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Title:
A RE-CIRCULATING HOT WATER SYSTEM ADAPTED FOR SUPPLY AND SPACE HEATING APPLICATIONS
Document Type and Number:
WIPO Patent Application WO/2004/070279
Kind Code:
A2
Abstract:
A re-circulating hot water system adapted for supply and space heating applications having a first re-circulating flow mode of operation and a second demand flow mode of operation and comprising a source of hot water, a hot water outlet and a duplex header connecting the source of hot water to the hot water outlet. The duplex header has a central fluid flow passage and an annular fluid flow passage. Flow from the source of hot water is directed into the system by way of the central fluid flow passage. Return counter-flow is directed back to the hot water source by way of the annular fluid flow passage. The header transports hot water from source of hot water to the outlet by duplex connecting conduits. There is also a source of replenishment water that is isolated from the system during the re-circulation mode and connected to the system during the demand mode to replenish consumed water. The duplex header re-circulates hot water between the outlet and the source of hot water thereby keeping the system temperature at a desired value. In the demand flow mode of operation there is hot water available at the outlet instantaneously.

Inventors:
STIRN DOUGLAS ROGER (CA)
Application Number:
PCT/CA2004/000168
Publication Date:
August 19, 2004
Filing Date:
February 09, 2004
Export Citation:
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Assignee:
STIRN DOUGLAS ROGER (CA)
International Classes:
F16L39/00; F24D3/08; F24D17/00; (IPC1-7): F24D3/08; F16L39/00; F24D17/00
Foreign References:
DE10054822A12002-05-08
DE10052097A12002-05-02
DE3542374A11987-05-21
DE19825553A11999-12-09
DE10164661A12003-10-30
DE20218316U12003-04-10
EP0997690A22000-05-03
FR1430376A1966-03-04
Attorney, Agent or Firm:
Thomson, Gordon J. (Ottawa, Ontario K1E 3G5, CA)
Download PDF:
Claims:
WHAT IS CLAIMED IS:
1. A recirculating hot water system adapted for supply and space heating applications, said system having a first recirculating flow mode of operation and a second demand flow mode of operation, the system comprising: a. a source of hot water ; b. a duplex header connected to said source of hot water, said duplex header having a central fluid flow passage and an annular fluid flow passage, the duplex header adapted to transport hot water in said first recirculating flow mode of operation and in said second demand flow mode of operation ; c. at least one hot water supply outlet connected to the source of hot water by the duplex header, said at least one hot water supply outlet having a first closed position corresponding to the recirculating flow mode and a second open position corresponding to the demand flow mode ; wherein, the at least one hot water supply outlet is connected to the duplex header by first duplex connection means; d. at least one hot water space heater connected to the source of hot water by the duplex header; wherein, said at least one hot water space heater is connected to the duplex header by second duplex connection means; and, e. a source of replenishment water connected to the source of hot water by first simplex connection means.
2. The system as claimed in claim 1, where: a. in the recirculating flow mode: i. the duplex header central fluid flow passage is adapted to transmit hot water from the source of hot water to the at least one hot water supply outlet; and, ii. the duplex header annular flow passage is adapted to return hot water to said source of hot water from the at least one hot. water supply outlet; and, b. in the demand flow mode : i. the duplex header central fluid flow passage is adapted to transmit hot water from the source of hot water to the at least one hot water supply outlet; and, ii. the duplex header annular fluid flow passage is adapted to transmit hot water from the source of hot water to the at least one hot water supply outlet.
3. The system as claimed in claim 2, wherein said first duplex connection means includes a first Tjoint adapted to join a first duplex conduit having a first central flow passage, a first annular flow passage and a first connecting end coaxially with a second duplex conduit having a second central flow passage, a second annular flow passage and a second connecting end, in a perpendicular relationship with a third duplex conduit having a third central flow passage, a third annular flow passage and a third connecting end, said first Tjoint comprising a body having: a. a first coupling adapted to connect the first Tjoint in a leak free relationship to said first duplex conduit first connecting end; b. a second coupling coaxial to said first coupling and adapted to connect the first T joint in a leak free relationship to said second duplex conduit first connecting end; c. a third coupling perpendicular to the coaxial first coupling and second coupling, said third coupling adapted to connect the first Tjoint in a leak free relationship to said third duplex conduit third connecting end; and, d. a hollow flow diverter located within said first Tjoint body creating a central passage way and an annular passage way within the first Tjoint body, said flow diverter having: i. a first tapered end adapted for connection in a leak free relationship to the first connecting end of the central flow passage of the first duplex conduit, ii. a second tapered end coaxial with said first tapered end and adapted for connection in a leak free relationship to the second connecting end of the second duplex conduit ; iii. a third tapered end perpendicular to said first and second coaxial tapered end and adapted for connection in a leak free relationship to the third connecting end of the third duplex conduit; so that, central passage flow in the first, second and third duplex conduits is contiguous and annular passage flow in the first second and third duplex conduits is contiguous.
4. The system as claimed in claim 3, further comprising: a. at least one duplex water purifier connected to the duplex header by third duplex connection means ; and, b. at least one simplex accumulator connected to the duplex header by fourth duplex connection means.
5. The system as claimed in claim 4, wherein the at least one hot water supply outlet comprises a base and a first hot water recirculating chamber; wherein, said first hot water recirculating chamber is closed when the at least one hot water supply outlet is closed and open and nonrecirculating when the at least one hot water supply outlet is open.
6. The system as claimed in claim 5, wherein said first duplex connection means further includes a first length of duplex conduit having a first end and a second end, wherein: a. said first end is connected to said hot water recirculating chamber, so that: i. in the first recirculating flow mode wherein the at least one hot water supply outlet is closed, hot water is received by the hot water recirculating chamber from the first central fluid flow passage way of said first length of duplex conduit and directed into the second annular fluid flow passage of the first length of duplex conduit ; and, ii. in the second demand flow mode wherein the at least one hot water supply outlet is open, hot water is received into the hot water recirculating chamber from the first central fluid flow passage way of the first length of duplex conduit and the second annular fluid flow passage of the first length of duplex conduit and directed into the open at least one out water supply outlet; and, b. said second end is connected to the duplex header by the first Tjoint, so that: i. in the first recirculating flow mode, the first duplex connection means is adapted to transmit hot water from the central passage of the duplex header to the hot water recirculating chamber by way of the central passage of the first length of duplex conduit ; and, to receive hot water from the hot water recirculating chamber through the second annular fluid flow passage of the first length of the duplex conduit for transmission into the annular fluid flow passage of the duplex header; ii. in the second demand flow mode, the first duplex connection means is adapted to transmit hot water demand flow from the central passage and annular passage of the duplex header into the respective central passage and annular passage of the second length of duplex conduit for release at the open at least one hot water supply outlet.
7. The system as claimed in claim 6, wherein said at least one space heater comprises: a. a second length of duplex conduit having a first end and a second end, wherein: i. said first end terminates in a second recirculation chamber; and, ii. said second end is connected to the duplex header by second duplex connection means so that in the recirculating flow mode and the demand flow mode hot water is transmitted from the central passage of the duplex header through the central passage of the said second length of duplex conduit to said second recirculation chamber wherein the hot water is directed into the second annular passage of the second length of duplex conduit for transport back to the annular passage way of the duplex header; b. heat radiation means surrounding the second length of duplex conduit, said heat radiation means adapted to absorb heat by conduction from the hot water within the second length of duplex conduit and radiate said heat into an adjacent space.
8. The system as claimed in claim 1, wherein said source of hot water comprises a hot water reservoir adapted to hold a predetermined volume of hot water and heat said predetermined volume of hot water to a predetermined temperature by heating means.
9. The system as claimed in claim 8, wherein said hot reservoir is a hot water tank having an outlet port and an inlet port; wherein, said outlet port is connected to the duplex header by a first recirculating flow mode pathway and a second demand flow mode pathway ; and wherein, said inlet port is connected to the duplex header by a second re circulating mode pathway.
10. The system as claimed in claim 9 wherein said first recirculating mode pathway comprises: a. a first length of simplex conduit having a first end and a second end, said first end connected to outlet port of said hot water tank and said second end connected to the duplex header by a fifth duplex connection means adapted to direct recirculating flow mode hot water from said hot water tank into the central fluid passage of the duplex header; b. a recirculating pump having an intake end connected to the first end of the first length of simplex conduit and a discharge end connected to the second end of the first length of simplex conduit wherein said pump is adapted to motivate hot water flow in the first recirculating flow mode from the hot water tank to the at least one closed outlet through the central flow passage of the duplex header; c. a temperature controller adapted to control the temperature of the system to a desired temperature in the first recirculating flow mode, said temperature controller logically connected to the pump so that pump speed can be controlled as a function of desired system temperature.
11. The system as claimed in claim 10, wherein said fifth duplex connection means comprises a second Tjoint adapted to join a first duplex conduit having a central flow passage, an annular flow passage and a connecting end with a first simplex conduit having a connecting end and a second simplex conduit having a connecting end, said second Tjoint comprising a body having: a. a first coupling adapted to connect the second Tjoint in a leak free relationship to said first duplex conduit connecting end; b. a second coupling coaxial to said first coupling and adapted to connect the second Tjoint in a leak free relationship to said first simplex conduit connecting end; c. a third coupling perpendicular to said second coupling and the first coupling, said third coupling adapted to connect the second Tjoint in a leak free relationship to said second simplex conduit connecting end; d. a hollow flow diverter located within said second Tjoint body, said flow diverter having: i. a first end connected in a leak free relationship to the connecting end of the central flow passage of the first duplex conduit, ii. a second end connected in a leak free relationship to the connecting end of the first simplex conduit; so that, flow from the first simplex conduit is diverted into the first duplex conduit central flow passage and flow from the first duplex conduit central flow passage is diverted into the first simplex conduit; and so that, flow from the annular passage of the first duplex conduit is diverted into the second simplex conduit and flow from the second simplex conduit is diverted into the annular passage of the first duplex conduit.
12. The apparatus as claimed in claim 11, wherein said second demand flow mode pathway comprises: a. a second length of simplex conduit having a first end and a second end, said first end connected to the hot water tank outlet port and said second end connected to the duplex header by sixth duplex connection means, said sixth duplex connection means adapted to direct demand flow from the second length of simplex conduit into the annular passage way of the duplex header; b. a first check valve having an inlet and an outlet, said inlet connected to the first end of the second length of simplex conduit and said outlet end connected to the second end of the simplex conduit; wherein; i. in the recirculating flow mode said first check valve is closed; and, ii. in the demand flow mode the first check valve is open to accommodate demand flow from the hot water tank through the second simplex conduit into the annular passage way of the duplex header.
13. The system as claimed in claim 11, wherein said sixth duplex connection means comprises a third Tjoint adapted to join a first duplex conduit having a first central flow passage, a first annular flow passage and a first connecting end coaxially with a second duplex conduit having a second central flow passage, a second annular flow passage and a second connecting end in a perpendicular relationship with a first simplex conduit having a connecting end, said third Tjoint comprising a body having: a. a first coupling adapted to connect the third Tjoint in a leak free relationship to said first duplex conduit first connecting end; b. a second coupling coaxial to said first coupling and adapted to connect the third T joint in a leak free relationship to said second duplex conduit second connecting end; c. a third coupling perpendicular to said second coupling and the first coupling, said third coupling adapted to connect the third Tjoint in a leak free relationship to said first simplex conduit connecting end; d. a hollow connector located within said third Tjoint body forming a central passage way and an annular passage way through the Tjoint, said connecting body having: i. a first tapered end connected in a leak free relationship to the connecting end of the central flow passage of the first duplex conduit, ii. a second tapered end connected in a leak free relationship to the connecting end of the central flow passage of the second duplex conduit; so that, flow from the first duplex conduit central passage flows into the second duplex conduit central passage and flow from the first duplex conduit annular passage flows into the annular passage of the second conduit; and so that, flow from the first simplex conduit is diverted around the connecting body into said annular passage way of the Tbody.
14. The system as claimed in claim 13, wherein said second recirculating mode pathway is adapted to receive recirculating flow from the annular passage of the duplex header while the system is in the recirculating mode and direct said recirculating flow to the hot water tank inlet; wherein, said second recirculating mode pathway comprises: a. a third length of simplex conduit having a first end and a second end, said first end connected to the inlet port of the hot water tank, and said second end connected to the duplex header by fifth duplex connection means adapted to direct recirculating hot water flow from the annular passage way of the duplex header into the second end of the third length of simplex conduit; b. a second check valve having an inlet and an outlet, said inlet connected to the second end of the third length of simplex conduit and said outlet connected to the first end of the third length of simplex conduit; wherein; i. in the recirculating flow mode said second check valve is open; and, ii. in the demand flow mode the second check valve is closed to prevent re circulating water from entering the hot water tank.
15. The system as claimed in claim 14, wherein, said source of replenishment water comprises a source of unheated water connected to the third length of simplex conduit by a fourth length of simplex conduit having: a. a first end connected to the source of cold water ; b. a second end connected to the third length of simplex conduit; c. a third check valve having an inlet connected to said first end of the fourth length of simplex conduit and an outlet connected to said second end of the fourth length of simplex conduit; wherein said third check valve is: i. closed in the recirculating flow mode; and ii. open in the demand flow mode so that replenishment water is permitted to enter the hot water reservoir.
16. A recirculating hot water system adapted for supply and space heating applications, said system having a first recirculating flow mode of operation and a second demand flow mode of operation, the system comprising: a. a source of hot water; b. a simplex header connected to said source of hot water, said simplex header adapted to transport hot water in said first recirculating mode of operation and in said second demand flow mode of operation; c. at least one hot water supply outlet connected to the source of hot water by the simplex header, said at least one hot water supply outlet having a first closed position corresponding to the recirculating flow mode and a second open position corresponding to the demand flow mode; wherein, the at least one hot water supply outlet is connected to the simplex header by first duplex connection means; d. a first hot water space heater connected to the source of hot water by the simplex header; wherein, said at least one hot water space heater is connected to the simplex header by second duplex connection means; e. a second hot water space heater connected to the source of hot water by the simplex header; wherein, said second hot water space heater is connected to the simplex header by second duplex connection means having a first duplex ball valve; and, f. a source of replenishment water connected to the source of hot water by first simplex connection means.
17. A recirculating hot water system adapted for supply and space heating applications, said system having a first recirculating flow mode of operation and a second demand flow mode of operation, the system comprising: a. a hot water tank having an inlet and an outlet; b. a duplex header connected to said hot water tank by connection means, said duplex header having a central fluid flow passage and an annular fluid flow passage, the duplex header adapted to transport hot water in said first recirculating flow mode of operation and in said second demand flow mode of operation; and, c. a source of replenishment water connected to the hot water tank by said connection means.
18. The system as claimed in claim 17 wherein said connection means comprises a solid body having a plurality of simplex conduits formed therein, said solid body adapted to connect the water tank to the duplex header and said source of replenishment water by said plurality of simplex conduits.
19. The system as claimed in claim 18, wherein said plurality of simplex conduits comprises at least: a. a first simplex conduit adapted to draw recirculating water flow from the hot water tank and into the central passage way of the duplex header, said first simplex conduit having: i. a first end connected to said outlet port of the hot water tank by a first connector fixed to the body; and. ii. a said second end connected to the duplex header by a second connector fixed to the body; wherein, said second connector includes a flow diverter upstream thereof and adjacent thereto, said flow diverter adapted to divert recirculating hot water from the hot water tank into the central passage way of the duplex header; iii. a recirculating pump having an intake end connected to the first end of the first simplex conduit and a discharge end connected to the second end of the first simplex conduit; wherein, said pump is adapted to motivate hot water flow in the first recirculating flow mode from the hot water tank into the central passage way of the duplex header; iv. a temperature controller adapted to control the temperature of the system to a desired temperature in the first recirculating flow mode, said temperature controller logically connected to the pump so that pump speed can be controlled as a function of desired system temperature; b. a second simplex conduit adapted to draw demand flow from the water tank outlet, said second simplex conduit having: i. a first end connected to the hot water tank outlet port; and, ii. a said second end connected to the duplex header by the second connector fixed to the body; wherein, demand flow is diverted from the hot water tank into the annular passage way of the duplex header; iii. a first check valve having an inlet and an outlet, said inlet connected to the first end of the second simplex conduit and said outlet end connected to the second end of the simplex conduit; wherein; 1. in the recirculating flow mode said first check valve is closed; and, 2. in the demand flow mode the first check valve is open to accommodate demand flow from the hot water tank through the second simplex conduit into the annular passage way of the duplex header; c. a third simplex conduit having: i. a first end connected to the inlet port of the hot water tank; ii. a second end connected to the duplex header by the second connection means so that the flow diverter diverts recirculating hot water flow from the annular passage way of the duplex header into the second end of the third simplex conduit; iii. a second check valve having an inlet and an outlet, said inlet connected to the second end of the third simplex conduit and said outlet connected to the first end of the third simplex conduit; wherein; 1. in the recirculating flow mode said second check valve is open; and, 2. in the demand flow mode the second check valve is closed to prevent recirculating water from entering the hot water tank. d. a fourth simplex conduit having: i. a first end connected to the third simplex conduit; ii. a second end connected to said source of replenishment water by way of a fourth connection means; iii. a third check valve having an inlet connected to said first end of the fourth simplex conduit and an outlet connected to said second end of the fourth simplex conduit; wherein said third check valve is: 1. closed in the recirculating flow mode; and, 2. open in the demand flow mode so that replenishment water is permitted to enter the hot water reservoir.
20. The system as claimed in claim 19, further including a pressure switch adapted to detect the pressure of the system during operation, said pressure switch logically connected to the recirculating pump and adapted to control the operation of the re circulating pump as a function of the detected pressure of the system.
21. A recirculating hot water system adapted for supply and space heating applications, said system having a permanent recirculating flow mode of operation, the system comprising: a. a source of hot water; b. a duplex header connected to said source of hot water, said duplex header having a central fluid flow passage and an annular fluid flow passage; c. a plurality of hot water space heater connected to the source of hot water by the duplex header; wherein, said plurality hot water space heaters are connected to the duplex header by a plurality of second duplex connection means; and, d. a source of replenishment water connected to the source of hot water by first simplex connection means.
22. The system as claimed in claim 21, wherein: a. the duplex header central fluid flow passage is adapted to transmit hot water from the source of hot water to the plurality of space heaters; and, b. the duplex header annular flow passage is adapted to return hot water to said source of hot water from the plurality of space heaters.
23. The system as claimed in claim 22 further comprising at least one simplex accumulator connected to the duplex header by first duplex connection means.
24. The system as claimed in claim 23, wherein each of the plurality of space heaters comprise: a. a length of duplex conduit having a first end and a second end, wherein: i. said first end terminates in a second recirculation chamber ; and, ii. said second end is connected to the duplex header by duplex connection means so that in the recirculating flow mode and the demand flow mode hot water is transmitted from the central passage of the duplex header through the central passage of the said second length of duplex conduit to said second recirculation chamber wherein the hot water is directed into the second annular passage of the second length of duplex conduit for transport back to the annular passage way of the duplex header; b. heat radiation means surrounding the second length of duplex conduit, said heat radiation means adapted to absorb heat by conduction from the hot water within the second length of duplex conduit and radiate said heat into an adjacent space.
25. The system as claimed in claim 24, wherein each of said plurality of second duplex connection means includes: a. a length of duplex conduit adapted in length to connect each of the plurality of space heaters to the duplex header; b. a duplex to duplex connector adapted to connect said length of duplex conduit to the duplex header so that central passage flow through the header is contiguous with central passage flow through the central passage of the duplex conduit and wherein annular flow through the header is contiguous with annular flow through the header is contiguous with annular flow through the duplex conduit; and, c. regulating valve means adapted to regulate both central passage flow and annular flow of hot water from the header into the length of duplex conduit.
26. The system as claimed in claim 25 wherein said regulating valve means is a ball valve that is manually operated.
27. The system as claimed in claim 26 wherein said regulating valve means is a ball valve that is electrically operated and further wherein said electrically operated ball valve is logically connected to a central thermostat so it may be controlled remotely.
28. The system as claimed in claim 27, wherein said source of hot water comprises a hot water reservoir adapted to hold a predetermined volume of hot water and heat said predetermined volume of hot water to a predetermined temperature by heating means.
29. The system as claimed in claim 28, wherein said hot reservoir is a hot water tank having an outlet port and an inlet port ; wherein, said outlet port is connected to the duplex header by a first simplex recirculating flow mode pathway and said inlet port is connected to the duplex header by a second simplex recirculating mode pathway.
30. The system as claimed in claim 29 wherein said first recirculating mode pathway comprises: a. a first length of simplex conduit having a first end and a second end, said first end connected to outlet port of said hot water tank and said second end connected to the duplex header by duplex connection means adapted to direct recirculating flow mode hot water from said hot water tank into the central fluid passage of the duplex header ; b. a recirculating pump having an intake end connected to the first end of the first length of simplex conduit and a discharge end connected to the second end of the first length of simplex conduit wherein said pump is adapted to motivate hot water flow in the first recirculating flow mode from the hot water tank to the at least one closed outlet through the central flow passage of the duplex header; c. a temperature controller adapted to control the temperature of the system to a desired temperature in the first recirculating flow mode, said temperature controller logically connected to the pump so that pump speed can be controlled as a function of desired system temperature.
31. The system as claimed in claim 30, wherein said second recirculating mode pathway is adapted to receive recirculating flow from the annular passage of the duplex header while the system is in the recirculating mode and direct said recirculating flow to the hot water tank inlet; wherein, said second recirculating mode pathway comprises: a. a third length of simplex conduit having a first end and a second end, said first end connected to the inlet port of the hot water tank, and said second end connected to the duplex header by fifth duplex connection means adapted to direct recirculating hot water flow from the annular passage way of the duplex header into the second end of the third length of simplex conduit; b. a second check valve having an inlet and an outlet, said inlet connected to the second end of the third length of simplex conduit and said outlet connected to the first end of the third length of simplex conduit; wherein; i. in the recirculating flow mode said second check valve is open; and, ii. in the demand flow mode the second check valve is closed to prevent re circulating water from entering the hot water tank.
32. The system as claimed in claim 31, wherein, said source of replenishment water comprises a source of unheated water connected to the third length of simplex conduit by a fourth length of simplex conduit having: a. a first end connected to the source of cold water; b. a second end connected to the third length of simplex conduit; c. a third check valve having an inlet connected to said first end of the fourth length of simplex conduit and an outlet connected to said second end of the fourth length of simplex conduit; wherein said third check valve is: i. closed in the recirculating flow mode; and ii. open in the demand flow mode so that replenishment water is permitted to enter the hot water reservoir.
33. A recirculating hot water system adapted for supply and space heating applications, said system having a first recirculating flow mode of operation and a second demand flow mode of operation, the system comprising: a. a hot water tank having a first port and a second port; b. a duplex header connected to said hot water tank by connection means, said connection means connecting said duplex header to said first port, said duplex header having a central fluid flow passage and an annular fluid flow passage, the duplex header adapted to transport hot water in said first recirculating flow mode of operation and in said second demand flow mode of operation; c. a pump having an intake end connected to said second port and a discharge end connected to the connection means; d. at least one hot water supply outlet connected to the source of hot water by the duplex header, said at least one hot water supply outlet having a first closed position corresponding to the recirculating flow mode and a second open position corresponding to the demand flow mode; wherein, the at least one hot water supply outlet is connected to the duplex header by first duplex connection means; e. a source of replenishment water connected to the hot water tank first simplex connection means.
34. The system as claimed in claim 33, where: a. in the recirculating mode: i. hot water is drawn by the pump from the tank into the pump intake through the second port and discharged into the central passage of the duplex header; ii. hot water is returned to the tank by way of the duplex header annular passage and diverted by connection means into the hot water tank through the first port; and, iii. replenishment water is isolated from the hot water tank; b. in the demand mode: i. hot water is drawn by the pump from the tank into the pump intake through the second port and discharged into the central passage of the duplex header; ii. hot water is drawn from the hot water tank first port into the duplex header annular passage and diverted by connection means into the annular passage of the duplex header, and, iii. replenishment water is permitted to flow to the hot water tank.
Description:
TITLE OF THE INVENTION A Re-circulating Hot Water System Adapted for Supply and Space Heating Applications.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of United States Provisional Patent Application 60/445,813 filed on February 10,2003.

BACK GROUND TO THE INVENTION Field of the Invention This invention relates to fluid handling and more specifically to a fluid recirculation system and components for energy and water conservation.

Discussion of the Known Art It is well known that in conduits connecting a hot water tank to a distant valve in a domestic or commercial hot water system there can be a significant volume of cold water. When the valve is opened and the hot water demanded from the hot water tank, this cold water must be evacuated from the conduits prior to hot water reaching the valve. This results in a wastage of potable water and energy as hot water and cold water will mix in the conduit quenching the hot water to below desired temperatures. Therefore it is necessary to continue to run the hot water until desired temperatures are reached.

A number of attempts have been made to reduce the wastage of water and energy caused by this problem. For example, United States Patent 2,915, 080"Control Means for Hot Water Systems" issued to Holmes on December 1, 1959 addresses the problem of cold water backing up into hot water pipes and provides for instant hot water when the hot water is demanded at the opened valve. Holmes teaches the installation of a pressure-sensitive float valve in the hot water return line that prevent cold water from entering the hot water line. The obvious shortcoming to this system is that the valve may leak or fail. As well, hot water held up in the conduits may continue to chill to ambient temperatures necessitating running the water until hotter water is available from the water tank. United States Patent 3,543, 836"Recirculation Unit"issued to Paulson on December 1,1970 teaches a system for maintaining hot water at the outlet fixture by mixing hot water with cold water at the fixture. The temperature of the water at the fixture is not permitted to fall below a predetermined temperature. When the temperature of the water in the hot water conduit falls below the predetermined value, the cooled water is circulated back to the hot water tank and hot water is pumped into the conduit to take its place. This type of system is energy inefficient as it requires the constant replacement and reheating of water in the hot water conduits.

Therefore there is a continued need for an energy and water efficient system that maintains hot water at a desired temperature at the hot water outlet. There is also a requirement for a system that eliminates the wastage of water caused by a lengthy waiting period endured until hot water issues from the faucet.

SUMMARY OF THE PRESENT INVENTION My invention is a re-circulating hot water system adapted for supply and space heating applications. The system has a first re-circulating flow mode of operation and a second demand flow mode of operation. The major elements of my invention comprise at least one hot water outlet valve such as a faucet, a source of hot water such as a hot water tank and a duplex header connecting the hot water tank to the faucet. "Duplex"means that the conduit or header has a central fluid flow passage and an annular fluid flow passage. The duplex header transports hot water from the hot water tank to the at least one faucet. My system also includes a source of replenishment water that is isolated from the system during the re-circulation mode and connected to the system during the demand mode to replenish consumed water. My system can optionally include a duplex water purifier and a simplex accumulator.

The primary advantage of my invention is that by the use of duplex conduits, water can be re- circulated in the system keeping the system temperature at a desired value. Typically, hot re- circulating water is supplied from the hot water tank to the system by way of the duplex header central passage way and returned to the hot water reservoir by way of the duplex header annular passage way. In demand flow mode, the pressure drop across the system caused by an open faucet, reverses the flow in the annular passage way of the duplex header and demand flow is supplied to the open faucet by both the central passage way and annular passage way of the duplex header. In demand flow mode, hot water is available at the open faucet at the desired temperatures instantaneously.

This prevents having to waste potable water waiting for the water to reach a desired temperature.

This also saves energy by using hot water held within the system during demand mode of operation without having to significantly draw down the hot water reservoir and adding cold replenishment water that will have to be heated to system temperature.

My invention contemplates the use of a variety of duplex conduits and means for joining these duplex conduits to each other and to simplex conduits. Other embodiments of my invention disclosed below are adapted for water supply and space heating applications.

My invention can also be used for chilled water flows rather than hot water flows.

OBJECTS AND ADVANTAGES OF THE PRESENT INVENTION It is an object of the present invention to overcome the deficiencies of the prior art.

It is a further object of the present invention to substantially reduce or eliminate the waiting time before hot water issues from a hot water outlet fixture.

Another object of the present invention is to prevent wastage of potable water in a domestic or commercial water system.

Yet another object of the present invention is to prevent wastage of energy in a hot water system.

A further object of the present invention is to be able to retrofit existing water systems to more energy and water efficient systems in a cost-effective manner.

Still further objects and advantages of the present invention will become apparent from a consideration of the ensuring description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a known simplex hot water supply and space heating system representative of the prior art.

Figure 2 is one embodiment of the re-circulating hot water system for hot supply and space heating applications of my invention shown in the re-circulating mode of operation.

Figure 3 is the same as Figure 2 used to describe additional features of my invention.

Figure 4 is an illustration in sectional view of a specialized T-joint (130) of my invention for converting duplex to simplex flow and simplex to duplex flow.

Figure 5 is an illustration in sectional view of another specialized T-joint (180) of my invention to receive simplex flow into the annular passage way of a duplex conduit.

Figure 6 is the same as Figure 2 and Figure 3 and is used to describe additional features of my invention.

Figure 7a and Figure b depict in sectional view a duplex to duplex T-joint (242) in a re-circulating mode and a demand mode respectively.

Figure 8 is a view of a duplex elbow joint in sectional view.

Figure 9 depicts the same system as depicted in Figure 2 but in the demand flow mode of operation, with the faucet open.

Figures lOa-lOd depicts a variety of duplex conduits adaptable for use in my invention.

Figure 11 illustrates in sectional view a T-joint adapted to connect a first split conduit to a first and second simplex conduits.

Figure 12 illustrates in sectional view a T-joint adapted to connect a first, second and third split conduits.

Figure 13 illustrates in sectional view a T-joint adapted to connect a first and second simplex conduits to a first split conduit.

Figure 14 illustrates in sectional view a T-joint adapted to connect a first split conduit to a first and second simplex conduits.

Figures 15a and 15b illustrate in sectional view a T-joint adapted to connect simplex conduit to a first and second split conduit in two flow modes.

Figure 16 illustrates in sectional view a"crow's foot"junction used for duplex conduits.

Figure 17 illustrates in section view a Y-joint used for duplex conduits.

Figures 18a, 18b and 18c illustrate a variety of arc connectors of my invention.

Figure 19 illustrates in sectional view a T-joint (740) having a flow diverter and adapted to connect first and second simplex conduits to a first duplex conduit.

Figure 20 illustrates in sectional view a T-joint (750) having a flow diverter and adapted to connect a first and second simplex conduit to a first duplex conduit.

Figures 21a and 21b illustrate in sectional view an adapter adapted to covert a simplex T-j oint into one that will accept a first duplex conduit.

Figure 21c illustrates in sectional view the adapter of Figure 21b having a ball valve.

Figure 22 illustrates a T-joint having a flow diverted that is adapted to connect three duplex conduits and divert annular flow to central passage flow.

Figure 23 illustrates in sectional view a duplex coupling adapted to join two duplex conduits co- axially.

Figure 24 illustrates in sectional view an adapter adapted to join a first duplex conduit having a first diameter with a second duplex conduit having a second diameter.

Figures 25a and 25b illustrate the bulk-head plate of one embodiment of my invention.

Figure 26 illustrates another embodiment of the re-circulating hot water system for supply and space heating applications using both simplex and duplex conduits.

Figure 26a illustrates another embodiment of my invention.

Figure 26b illustrates yet another embodiment of my invention.

Figure 26c illustrates still another embodiment of my invention.

Figure 26d illustrates another embodiment of my invention.

Figure 26e shows another embodiment of my invention.

Figure 27 illustrates in sectional view the uni-block manifold block of one embodiment of my invention in a re-circulating mode.

Figure 28 illustrates in sectional view the uni-block manifold block of Figure 27 in demand flow mode.

Figures 29a and 29b illustrate in sectional view a manifold block of another embodiment of my invention.

Figure 30 illustrates another embodiment of the re-circulating hot water supply and space heating system of my invention.

Figures 31a, 31b and 31c illustrate yet another embodiment of my invention in the re-circulating and demand modes.

Figures 32a and 32b illustrate in sectional view means for converting a simplex T-joint into a duplex-joint adapted to connect three duplex conduits.

DETAILED DESCRIPTION Referring to Figure 1, there is shown a prior art hot water supply and hot water space heating system (1700) in the re-circulating mode. All of the conduits and peripheral devices attached to the system are"simplex", that is, as more fully explained below, they comprise a conduit having a single passage way. The system includes a hot water reservoir (1702) from which hot water is drawn by pump (1704) intake from reservoir outlet (1706) by way of coupling (1708) into conduit (1710) and by way of elbow (1712) into conduit (1714). The pump discharges hot water into elbow (1716) and by way of T-joint (1718) and coupling (1719) into space heater (1720). T-joint (1718) also discharged hot water into T-joint (1722) connected to closed faucet (1724) by way of conduit (1726). When the faucet is closed, there is no hot water supply demand and hot water is re-circulated by way of conduit (1728) back towards the hot water reservoir (1702) by way of T- joint (1731), conduit (1730) and open check valve (1732). Hot water space heater is connected to the re-circulation conduit (1728) at T-joint (1734) by way of elbow (1736). An accumulator (1740) is jointed to the system at T-joint (1731) by way of conduit (1740) and elbow (1742). Also shown in Figure 1 is cold water supply conduit (1744) that is connected to conduit (1730) by way of conduit (1731) containing check valve (1733) that remains closed until there is a demand on the system. T-joint (1746) connects conduit (1731) to conduit (1744) and permits cold water passage to the faucet (1724). In the prior art system shown in Figure 1, lengthy pipe-runs from the hot water reservoir to the faucet will cause a significant heat loss in the system even if the piping is insulated. Heat loss is further exacerbated by space heater (1720). Therefore, when the faucet is opened, hot water in the system will have cooled to below desirable temperatures. This necessitates maintaining the faucet in an open position until hot water of a desirable temperature reaches the faucet. This situation creates a water demand situation that wastes potable water and energy used to heat the water. As well, when the cold water replenishment check valve (1733) is open in demand flow conditions, cold water entering the hot water reservoir will have the effect of further cooling the hot water and creating more energy demand to add heat. My invention

provides for a hot water supply and heating system that is energy and water efficient and avoids the problems noted above.

Referring to Figure 2, there is depicted one embodiment of my invention (10) for a re-circulating hot water system adapted for supply and space heating applications being a fluid re-circulation system for energy and water conservation having a first re-circulating mode of operation (depicted in Figure 2) and a second demand mode of operation (depicted in Figure 9). The system comprises a hot water supply and re-circulation header (16) comprising a plurality of joined passage conduits having therein a first central fluid flow passage way (20) and a second fluid flow passage way (22) annular to the first central fluid flow passage way (20). Throughout the detailed description and claims herein, a dual passage conduit having a central passage way and an annular passage way will be referred to as"duplex conduit". Similarly, connectors, joints and branches that utilize dual passage flow are referred to as"duplex connectors", "duplex joints"and the like.

A person skilled in the art will understand that there may be several such branches, faucets, and or appliances incorporated within a typical household hot water system, and that these illustrations are abbreviated for clarity purposes.

At least one hot water supply outlet such as faucet (12) is connected to the duplex header (16) by first duplex connection means including duplex conduit (24) through a duplex elbow (27) and duplex conduit (25) to first T-joint (242). The faucet depicted in Figure 2 is a typical hot/cold water faucet generally found in domestic applications. A person skilled in the art will understand that the design of the faucet is not determinative of the function of the invention, and that any type of faucet or valve can be used with the invention as long as the faucet connection permits the flow of fluid from the central passage way of a duplex conduit into the annular passage way of duplex conduit as indicated at (29) in the re-circulation mode. The hot water faucet has a first closed position (depicted in Figure 2) when the system is in its first re-circulating mode of operation. The faucet has a second open position (depicted in Figure 9) when the system is in its second demand mode of operation.

The system (10) in Figure 2 further comprises a source of hot water such as a hot water heater- reservoir (14) which may also be a hot water heater-boiler as commonly found in domestic and

commercial applications being oil fired, gas fired, electrically heated or the like and is connected to the duplex header (16) by means of a first re-circulating hot water outlet single fluid passage way conduit (30) having an first inlet end (32) and an first outlet end (34). The hot water heater- reservoir (14) is adapted to store a predetermined volume of water at a predetermined temperature.

The term"single fluid passage way conduit"means that the conduit has a single passage, as is the case for all single wall conduits such as copper or PVC tubing or similar single-wall plumbing conduits. Throughout the description and claims herein, "single fluid passage way conduit"will be referred to a"simplex conduit". First simplex conduit (30) is connected to second simplex conduit (40) at simplex T-joint (46) and includes pump (120) discharging through simplex elbow (31) into fifth duplex connection means including specialized second T-joint (130) connecting simplex conduit (30) second end (34) to the duplex header (16) central passage (20). There is also included water system temperature gauge (36) that, by adding control means, can be adapted to regulate the hot water temperature by controlling pump (120) by way of logic connection (43).

This type of control is well known in the art and need not be further described herein. In Figure 2 the re-circulation water outgoing flow from the heater-reservoir (14) is depicted by the white arrows (38) and the return flow is depicted by black arrows (62).

Figure 2 also depicts second demand hot water simplex outlet conduit (40) having a second inlet end (42) and a second outlet end (44). The first inlet end (32) of the first simplex conduit (30) is connected by simplex T-joint (46) to the second simplex conduit (40) between the second inlet end (42) and the second outlet end (44). The second inlet end (42) is connected to the hot water reservoir (14) outlet port (15) by way of simplex coupling (50) and is adapted to draw water from the hot water reservoir in both the first re-circulating mode and the second demand mode of the system as further described herein. Also in simplex conduit (40) is check valve (160). Second end (44) of simplex conduit (40) is connected by sixth duplex connection means including specialized third T-joint (180) to duplex header (16) annular flow passage (22).

Figure 2 further depicts a third re-circulating hot water simplex inlet conduit (52) having an inlet end (54) connected to the duplex header (16) annular flow passage at specialized Tjoint (130) by way of simplex elbow (58) and an outlet end (56) connected to the hot water reservoir (14) inlet port (17) at simplex coupling (64). As further explained herein, the third simplex conduit (52)

directs re-circulation water flow (62) from the duplex header annular passage way (22) into the hot water reservoir (14) during the system re-circulation mode of operation. Second T-joint (130) is adapted to direct duplex header (16) annular return flow (62) into the simplex third conduit (52).

Still referring to Figure 2, there is shown a source of reservoir replenishment water (66) which in this embodiment is the simplex cold water pipe connecting water mains (68-not shown) to the cold water side (70) of faucet (12). Simplex cold water pipe (66) is connected to the cold water side (70) of faucet (12) through a plurality of simplex elbow joints (72). A person skilled in the art will understand that a plurality of different joints may have to be used to suit a given installation.

First simplex connection means includes a fourth replenishment simplex conduit (80) having a fourth inlet end (82) and a fourth outlet end (84) connects the simplex cold water pipe (66) at simplex T-joint (92) to the third simplex conduit (52) at simplex T-joint (90) between the third outlet end (56) and third inlet end (54). Check valve (220) controls replenishment flow into the reservoir (14).

Still referring to Figure 2, there is shown in this re-circulating hot water supply and space heating embodiment of my invention (10) at least one space heater (100) connected to the duplex header (16) by second duplex connection means including duplex conduit (102). Space heater (100) is adapted to heat a volume of space such as a room by way of radiating heat from duplex conduit (102) by radiator means (300). There may be a plurality of space heaters connected to the system.

The hot water supply embodiment of the invention (10) may optionally include a duplex conduit configured water purifier (104) connected to the header (16) third duplex connection means including duplex conduit (106) and T-joint (111). There is also a simplex accumulator (108) connected to the header (16) by fourth duplex connection means including simplex conduit (110) and T-joint (109). The accumulator is adapted to mitigate against pressure transients in the system due to thermal expansion, and the opening and closing of valves that may cause water hammer effects.

Referring now to Figure 3, there is shown the same re-circulating hot water supply and space heating embodiment of my invention (10) as depicted in Figure 2 but for neatness and to avoid

clutter, Figure 3 will be referred to in the discussion of further features of my invention. The simplex conduit (30) includes pump (120) having an intake end (122) and a discharge end (124).

Intake end (122) is illustrated as connected by way of a simplex T-joint (46) to simplex conduit (40). Discharge end (124) the pump (120) is connected to duplex header (16) at second T-joint (130) through simplex elbow (31). There is also shown thermostat (36) that can be logically connected (43) to pump (120) to regulate system temperature between desired set points by controlling the activation and speed of the re-circulating pump. Pump (120) is generally electrically motivated by AC or DC power depending on the installation needs. For example, in a recreational vehicle installation the pump may be DC or both AC and DC. In a domestic home or commercial application, the pump may be AC. The pump is sufficiently sized to provide a suitable volume of re-circulating water flow (38) that will maintain the system at the desired flow rates and temperature. Simplex conduit (30) outlet end (34) is connected to the duplex header (16) by way of second T-joint (130). Second T-joint (130) is further illustrated in Figure 4.

Referring to Figure 4, there is shown a cross-sectional view of second Tjoint (130) of the type used to connect first simplex conduit (30) end (34) to the duplex header (16) at coupling (132) and third simplex conduit (52) end (54) to the duplex header (16) at coupling (134). Illustrated clearly in Figure 4 is the duplex nature of header (16) having a first central fluid flow passage way (20) and a second annular fluid flow passage way (22). The duplex header (16) is joined to second T- joint (130) at coupling (136). These couplings and all couplings indicted herein may be threaded couplings, glued couplings, welded couplings, soldered couplings, mechanical press fit couplings or any other type of coupling that a person skilled in the art may deem suitable for the application.

Re-circulating water flow depicted by arrows (38) is discharged from pump (120) and directed into the duplex header central passage (20) through flow director (140). Flow director (140) constricts and accelerates flow from simplex conduit (30) into duplex header (16) central passage (20). Inlet end (142) of director (140) is adapted for abutment against simplex conduit second end (34) and flow director second end (144) is narrowed to join duplex header (16) inner passage way (20) tubular wall (31) in a leak resistant fitting. Return water flow depicted by arrows (62) flows around director (140) and into simplex conduit (52) because the diameter of director (140) is less than the diameter of duplex header (16). As well there is no leakage around the connection

between director first end (142) and simplex conduit (30) outlet end (34) so that cooler return water does not intermingle with hot re-circulating water (38).

Referring back to Figure 3, there is illustrated conduit (40) including a first check valve (160) between inlet end (42) and outlet end (44) of simplex conduit (40). First check valve (160) is a typical ball type check valve having an inlet (161), an outlet (163) and a spring (162) biasing a ball (164) against the valve inlet (161). When faucet (12) is closed and system (10) is in its re- circulation mode, there is negligible pressure drop between the faucet and the hot water reservoir.

Therefore, spring (162) in first check valve (160) is powerful enough to bias ball (164) against inlet (161). However, when the faucet (12) is open there is a significant pressure drop across the system (10) between the open faucet (12) and hot water reservoir (14). This causes water from reservoir (14) to impinge upon ball (164) and lift it against spring (162) thereby permitting full demand flow from reservoir (14) into system (10) by way of third T-j oint (180).

Still referring to Figure 3, second end (44) of simplex conduit (40) is connected to duplex header (16) at T-joint (180) so that fluid from outlet end (44) is directed into annular passage way (22) of the duplex header (16).

Referring to Figures 5a and Sb, there is illustrated a sectional view of third T-joint (180). Figure 5a illustrates third T-j oint (180) when system (10) is in re-circulation mode and Figure 5b illustrates the same when system (10) is in demand mode.

Referring to Figure 5a third T-joint (180) is shown having three couplings (182), (184) and (186).

Second end (44) of simplex conduit (40) connects to duplex header (16) at coupling (186). During the re-circulation mode, there is no flow from simplex conduit (40) and return flow (62) by way of annular passage (22) proceeds unimpeded towards the hot water reservoir (14). Return flow may fill check valve (160) and second end (44) without consequence as there is no leakage across the check valve and the temperature of the return flow is not much lower than the temperature of the re-circulating flow at the ball end of the closed check valve. Within the T-joint and in order to connect sections of duplex header (16) together there is a hollow connector (190) having tapered

ends (192) and (194) that permit easy insertion of the duplex header ends into T-joint (180) and continual flow through flow passage (20).

Referring to Figure 5b, in demand mode, check valve (160) is opened and demand flow is permitted from hot water reservoir (14) into duplex header annular passage way (22). Note that flow in the annular passage (22) is reversed due to the pressure differential across the system caused by the open faucet and thereby able to accommodate demand flow. Demand flow is able to enter the header annular passage around the connector (190) as illustrated.

Referring back to Figure 3, there is illustrated third simplex conduit (52) including second check valve (200) between third inlet end (54) and third outlet end (56). Check valve (200) is generally identical to first check valve (160) and operates based on the pressure differential between the hot water reservoir (14) and the faucet (12). Ball (204) and spring (206) are adapted to remain in an open position while the system is in re-circulation mode to permit return water flow (62) into hot water reservoir (14). As illustrated and discussed herein, when the system is in demand mode with faucet (12) open the pressure differential between the water reservoir (14) and the open faucet (12) will, with the bias force of spring (206), overcome the weight of ball (204) and return water flow (62) to close check valve (200) preventing further flow into the hot water reservoir, and preventing cold make-up water from entering the hot water system.

Also shown in Figure 3, is third check valve (220) in simplex conduit (80). Third check valve (220) is substantially identical to the other previously described check valves being of the ball (222) and spring (224) type. Third check valve (220) controls flow of hot water reservoir replenishment water from the simplex cold water line (66) into simplex conduit (52). When the system is in re-circulation mode the valve is in a closed position as illustrated in Figure 3, thus preventing cold water from entering the hot water system. When the system is in demand mode when the faucet (12) is open, the pressure differential across the system overcomes the bias of spring (224) against ball (222) and the third check valve is opened thereby permitting replenishment water to enter the hot water reservoir.

Referring now to Figure 6, there is shown the same re-circulating hot water supply and space heating embodiment of my invention as shown in Figures 2 and 3. Figure 6 is used to illustrate further features of the system (10) without overcrowding the drawings. With reference to Figure 6, faucet (12) is connected to duplex header (16) by way of duplex conduit (24), elbow (27) and duplex conduit (25). Duplex conduit (24) has a first end (240) connected to duplex header (16) by duplex T-joint (242) and a second end (244) connected to duplex elbow (27). Conduit (25) has a first end (247) connected to the duplex elbow and a second end (249) terminating adjacent to the hot water side (71) of faucet (12). Faucet (12) includes a base (11) and a chamber (245) below the base that permits hot water from the central passage of conduit (25) to enter the chamber and be directed back into annular flow passage of conduit (25) for transportation back to the header (16).

Referring to Figure 7a and 7b there is illustrated duplex first T-joint (242) in cross section in re- circulation mode and demand mode respectively. This type of duplex of T-joint connector is used to connect the faucet (12) to the duplex header (16) and the duplex water purifier (104) to the duplex header (16). Duplex first T-joint (242) comprises three couplings (290), (292) and (294).

There is also a hollow flow diverter (296) having first, second and third tapered ends (291) (293) and (295) respectively that are adapted to receive duplex conduit connecting ends in a leak resistant relationship. A person skilled in the art will understand that this configuration of Tee joint may be installed wherever a"duplex"branch is required on a full"duplex"system.

As illustrated in Figure 6, (and with reference to Figure 7a), in re-circulation mode, central passage (20) flow is received at first coupling (290) and passes through the T-joint into third co-axial coupling (294) and then to the space heater (100) at duplex elbow (250). A portion of the flow through passage way (20) is directed into the central passage of duplex conduit (24) and towards closed faucet (12) to maintain that conduit at a desired temperature and to facilitate instantaneous hot water supply at open faucet (12) where it enters chamber (245) and is returned through annular passage way (22) to mix with annular flow from heater (100) at T-joint (242) for transport back to hot water reservoir (14). Referring to Figure 7b, when faucet (12) is open, both annular flow and central passage flow are directed towards the open faucet.

Referring to Figure 8, there is illustrated a duplex elbow joint (250) in cross section. All duplex elbows are similar. The duplex elbow joint is adapted to join at right angles two sections of duplex conduit (24) from T-joint (242) to elbow (250) and duplex conduit (25) from elbow (250) to faucet (12). The duplex elbow comprises first end coupling (252) and second end coupling (254). Within the elbow joint (250) is a connector (256) adapted to join the first and second coupling together in a leak free manner. The duplex elbow retains continuity of flow in both the central passage (20) and annular passage (22) Referring back to Figure 6, the terminal end (249) of the second duplex conduit (25) is located within chamber (245) at closed faucet (12). Within the chamber the re-circulating flow exits the central passage (20) and is directed back into the annular passage (22) for re-circulation back to the hot water reservoir (14). When the faucet is opened, the chamber is opened and re-circulating annular flow is reversed into demand flow towards the open faucet as a result of the pressure drop across the system. The advantage of my invention is that since the water temperature in the system is maintained at a desired temperature during re-circulation mode, hot water supply is instantaneous and there is no need to waste potable waiting for suitable hot water to arrive at the faucet from the hot water reservoir.

Referring still to Figure 6, there is shown space heater (100) comprising heat radiating element (300) disposed around duplex conduit (102). Duplex conduit (102) has a first end (302) connected to the header (16) by elbow joint (250) and a second end (304) terminating in chamber (306) so that in the chamber flow from the first central flow passage way is directed into the second annular passage way back to the header annular passage way.

Referring to Figure 6, the system (10) includes a duplex water purifier (104) comprising duplex conduit (106) having a first end (310) connected to the duplex header by way of duplex T-joint (111) that is identical to duplex T-joint (242) illustrated in Figures 7a and 7b so that flow received from flow passage (20) of the duplex header is directed into the central flow passage of conduit (106). Conduit (106) has a second end (312) that terminates in chamber (314) adapted to direct flow from the central flow passage into annular flow passage and back towards the duplex header annular passage (22) for transport back to hot water reservoir (14). The water purifier includes a

source of ultra-violet radiation (316) disposed around duplex conduit (106) and duplex conduit (106) is adapted to be transparent to ultraviolet radiation.

Figure 6 also illustrates simplex accumulator (108) connected to the annular passage (22) of duplex header (16) at specialized T-joint (180). The accumulator acts to dampen pressure spikes within the system to avoid water hammer events.

Referring back to Figure 2, system (10) is illustrated in re-circulation mode with faucet (12) closed. In re-circulation mode: faucet (12) is closed; check valve (160) is closed; check valve (200) is open; and check valve (220) is closed. Pump (120) is operating and hot water for re- circulation is drawn from hot water reservoir (14) through simplex conduit (30) by pump (120) and discharged into central flow passage (20) of duplex header (16) for transport to faucet (12) and space heater (100). Re-circulating hot water is returned to the hot water reservoir (14) by way of the annular passage (22) of duplex header (16) through the second open check valve (200).

Although not shown in any figures of this application, it is to be understood by a person skilled in the art that the conduits, joints and system components described herein may be covered with a suitable insulating material to prevent heat loss from the system.

Referring now to Figure 9, there is shown system (10) of the re-circulating hot water supply and space heating embodiment of my invention in demand mode. In demand mode faucet (12) is open.

Faucet (12) may be fully open to hot water or it may be partially open to hot water and to cold water from simplex cold water conduit (66). In demand mode check valve (160) is open due to the pressure differential across the open system acting on spring (162) and ball (164). Therefore, there is demand flow through simplex conduit (40) direct from the reservoir (14) into the annular passage (22) of duplex header (16) through check valve (160). There continues to be re- circulating flow through pump (120) into duplex header (16) central flow passage way (20). The pressure differential across the system caused by open faucet (12) acts to close second check valve (200) to prevent cold replenishment water from entering hot water system. Check valve (220) is drawn open by the pressure differential across the system so that replenishment water from simplex cold water conduit (66) can enter hot water reservoir (14) to make up any demand flow.

Water continues to circulate through purifier (104) and space heater (100). Accumulator (108) acts to maintain a suitable pressure on the system to avoid water hammers due to the pressure transient from closed faucet to open faucet. Once the faucet is closed, the system reverts to the re- circulation mode as shown in Figure 2 Referring now to Figure l Oa to lOd, and as noted above, header (16) comprises a duplex conduit.

My invention provides for different embodiments of duplex conduit all permitting flow in opposite directions within the same conduit. Figure 1 Oa illustrates one embodiment (401) of the dual passage way conduit in which the central passage way (400) is fixed to the inside wall (402) of annular passage way (404). In another embodiment (406) of duplex conduit the central passage way (408) is suspended in the middle of the conduit by means of webs (410) and (412) thereby creating a first (414) and a second (416) annular passage ways. Figure l Oc illustrates a third embodiment (420) of the header conduit of my invention wherein the central passage way (422) is suspended in the outer conduit by spacer means (424) at either end of the duplex conduit. Figure 10d illustrates a fourth embodiment (430) of the dual passage way conduit wherein the inner passage (432) of the conduit is split by a continuous dividing member (434) into a first (436) and second (438) passage ways. This configuration of conduit shown in Figure l Od is hereafter referred to as a"split conduit". It is to be understood that in embodiments shown in Figures 10a to l Oc the size of the inner passage with respect to the size of the annular passage may vary, but generally, the annular passage is capable of receive a much larger flow volume than the inside passage of the conduit in order to accommodate demand flow in an open system. In Figure 1 Od, the dividing member of the split conduit may split the conduit in half as shown but is may also provide for two unequal passage ways. A person skilled in the art will understand that the embodiment of the dual passage way conduit chosen will be determined on the basis of application needs and material availability.

Employing a variety of dual passage way conduits necessitates the availability of various embodiments of elbow joints and T-joints adapted to convert simplex flow to duplex flow. For example, when using the split conduit configuration illustrated in 10d, a T-joint could take the forms as discussed and illustrated below and which form part of my invention.

Referring to Figure 11, there is shown a specialized T-joint (450) of one embodiment of my invention adapted to the split conduit of Figure 10d. The T-joint (450) comprises three couplings (452), (454) and (456). This T-joint is adapted to joint a first simplex conduit (458) co-axially with a second simplex conduit (460) and a perpendicular first split conduit (462) having flow in one direction in a first side of the split conduit (464) and flow in a second opposite direction in the second side of the split conduit (466). The split conduit (464) dividing member (468) terminates in a plug (470) adapted to terminate flow from simplex conduit (458) and direct it into first side (464) of split conduit (462). Flow from the second side (466) of the split conduit (462) is directed into simplex conduit (460).

Figure 12 illustrates another embodiment of a T-joint adapted for use with split conduits of the type illustrated in Figure l Od. Figure 12 illustrates T-joint (472) having three couplings (474), (476) and (478). The couplings are adapted to join the T-joint (472) with a first (480) split conduit co-axially with a second (482) split conduit and a perpendicular third (484) split conduit. The T- joint contains a plug (486) that is adapted to meet the dividing members (488), (490) and (492) of the first, second and third split conduits respectively in a sealing engagement. T-joint (472) is adapted to permit flow from conduit (482) into conduit (480) through the top sections (498) and (496) respectively. As well, the T-joint (472) is adapted to direct flow from lower half (500) of split conduit (480) into the first half (502) of split conduit (484). Similarly, flow from the second half (504) of the split conduit (484) is directed into the lower half (506) of split conduit (482).

Referring to Figure 13, there is shown another embodiment of a T joint (520) adapted for split conduits of the type illustrated in Figure 10d. T-joint (520) comprises three couplings (522), (524) and (526) adapted to receive a first split conduit (528) co-axially with a first simplex conduit (530) and a perpendicular second simplex conduit (532). Flow from the first simplex conduit (530) is directed into the top passage way (534) of the first split conduit (528). Flow from the bottom passage way (536) of the split conduit (528) is directed into simplex conduit (532). The flows are segregated by way of plug (538) within the T-joint (520).

Referring to Figure 14 there is shown yet another embodiment of a specialized T-joint (540) adapted to direct flow between a first simplex conduit (542), a co-axial second simplex conduit

(544) and a perpendicular first split conduit (546) having a first half passage way (548), a second half passage way (550) and a dividing member (552) between them. Flow from simplex conduit (542) is permitted to flow around plug (554) and into simplex conduit (544). A portion of flow from simplex conduit (542) is directed by plug (554) into first half passage way (548) of split conduit (546). Flow from the second half passage way (550) of split conduit (546) is directed by plug (554) onto second simplex conduit (544). The T-joint (540) comprises couplings (556), (558) and (560) that are adapted to accept conduits (542), (544) and (546) respectively.

Referring now to Figures 15a and 15b there is shown yet another embodiment of a specialized T- joint (570) used to joint a perpendicular simplex conduit (582) with a co-axial first split conduit (580) and second split conduit (578). T-joint (570) includes a first (572), second (574) and third (576) couplings. As illustrated in Figure 15a and Figure 15b the couplings are adapted to accept the conduits (578), (580) and (582) respectively. Figure 15a illustrates conduit (580) co-axially joined to conduit (578) so that the top half (584) of conduit (580) and the bottom half (586) of conduit (580) are contiguous with the top half (588) of conduit (578) and the bottom half (590) of conduit (578) respectively. As well the dividing member (592) in conduit (580) and the dividing member (594) in conduit (578) are joined by member (596) within the T-joint so that there is leak free continuity between them. As illustrated in Figure 15b and by way of example only, flow from perpendicular simplex conduit (582) is directed by T-joint (570) into the lower passage (590) of split conduit (578).

Figures 2 to 9 illustrate various embodiments of the system of my invention and those couplings, elbows and T-joints used when a duplex conduit of the type illustrated in Figure 10b and Figure l Oc are used or when a similarly configured duplex conduit having a central first fluid passage way and an annular second passage way are used. My invention, by way of necessity, contemplates additional configurations of joints, elbows, T-joints, arc-connections and branches all configured for use on duplex conduit illustrated in Figures 2 and 3. These are described as follows and are part of my invention described herein.

Referring now to Figure 16 there is shown a branch joint (600), generally called a"crow's foot"of one embodiment of my invention. The branch joint is adapted to join four duplex conduits having

a first central passage way and a second annular passage way of the type illustrated in Figures 2 and 3. Branch joint (600) comprises a body (602) having a first (604), a second (606), a third (608) and a fourth (610) coupling. Within the body (602) is first inlet (612) and first (614), second (616) and third (618) outlets. First inlet (612) is adapted to accept central passage (620) flow from conduit (622) and distribute it into the central passages (624), (626) and (628) of conduits (630), (632) and (634) respectively. Body (602) of branch joint (600) also includes internal passages (636), (638), and (640) adapted to accept annular flow from annular passages (642), (644) and (646) respectively so that they are merged within the body (602) and directed into annular passage (648) of conduit (622).

Figure 17 illustrates a Y-joint of one embodiment of the invention. The Y-joint (680) comprises a body (682) having three couplings (684), (686) and (688) adapted to receive duplex conduits (690), (692) and (694) respectively. Within body (682) is an inlet central passage way (696) splitting into a first outlet passage way (698) and a second outlet passage way (700). Passage way (696) is adapted to accept inlet flow from the central passage way (702) of conduit (692) and divert it into the central passage way (704) of conduit (690) and passage way (706) of conduit (694). Similarly, body (682) includes annular passage ways is adapted to receive flow from annular passage way (710) of conduit (690) into body annular passage way (716) and from annular passage way (712) of conduit (694) into body annular passage way and combine them into body annular passage way (718) and direct the combined flow into annular passage way (714) of conduit (692).

Referring now to Figure 18a, 18b and 18c there are shown embodiments of arc connectors used in my invention and to be considered part thereof. It is obvious to a person skilled in the art that some installations are not suitable for straight conduits and, particularly, some joints will require arc connectors. My invention provides for such arc connectors manufactured from a suitable material. Figure 18a illustrates in partial cross section an arc connector comprising a first coupling (722) and a second coupling (724). Between the couplings is duplex conduit (721) having a central fluid flow passage (726) and annular flow passage way (728). Generally, these arc connections will be relatively short. Figure 18a illustrates an arc connector capable of a 45 degree

change in direction. Figure 18b shows an arc connector (734) having a right angle change of direction and Figure 18c shows an arc connector (736) having a 180 degree change of direction.

Referring now to Figure 19, there is shown T-joint (740) adapted to connect a duplex conduit (742) with two simplex conduits (744) and (746). T-joint (740) comprises a body (748) having three couplings (750), (752) and (754). T-joint (740) is adapted to receive flow from simplex conduit (744) and direct it by way of flow diverter (756) into the central passage way (760) of conduit (742). The flow diverter (756) first end (762) seals the end of conduit (744) in a leak free relationship so that all of the flow from conduit (744) is channeled to the flow diverter second end (764) which is connected in a leak free relationship to the end of the fluid passage way (760).

Flow from the annular passage way (764) of conduit (742) is diverted by diverter (756) into the single passage conduit (746).

Referring now to Figure 20, there is shown another embodiment of a T-joint (750) of my invention that is adapted to divert partial flow from a first simplex conduit (752) into the central passage way (754) of a duplex conduit (756) and direct flow from the annular passage way (758) of conduit (756) into simplex conduit (760). T-joint (750) comprises a body (762) having three couplings (764), (766) and (768) that are adapted to connect to simplex conduit (760), simplex conduit (752) and duplex conduit (756) respectively. Within the body (762) of T-joint (750) there is flow diverter (770) having a right angle bend and a first end (772) adapted to direct partial flow from conduit (752) to second end (774) and into the central passage way (754) of conduit (756).

Referring now to Figure 21a and Figure 21b there is shown another embodiment of a T-joint (780) of my invention. T-joint (780) is representative of a standard simplex T-joint and comprises a body (782) having three couplings (784), (786) and (788). The couplings are adapted to receive simplex conduits with coupling (784) in receipt of conduit (790) and coupling (786) in receipt of simplex conduit (792). Coupling (788) is also adapted to receive a simplex conduit but is convertible to receive a duplex way conduit by way of adapter (794) shown in Figure 21b. The adapter comprises a head piece (796) attached to a coupling (798) and is adapted to receive a duplex conduit (800) having a central passage way (802) and an annular passage way (804). The adapter has a central passage way (806) and an annular passage way (808) that are adapted to

connect to central passage way (802) and annular passage way (804) respectively of the duplex conduit (800). Adapter (794) is inserted into the simplex T-joint (780) body at coupling (788) so that the head piece (794) of the adapter (794) diverts a portion of the flow from conduit (790) into central passage (806) of the adapted and into central passage (802) of duplex conduit (800). Flow in the annular passage (804) is transported through the head piece (794) by way of annular passage (808) and directed into simplex flow of conduit (792). The adapter is inserted into the coupling (788) in a leak free relationship.

Referring to Figure 21c, the adapter may include a ball valve (807) having a first open position and a second closed position and adapted to terminate flow through the adapter in annular passage (808) and central passage (806). Valve (807) comprises a handle (801) connected by way of an axis (803) to ball (805). Ball (805) has a first annular passage (811) and a second central passage (813) adapted to permit flow through adapter when the valve is in its first open position and the annular passage (811) is in communication with annular passage (808) and central passage (813) is in communication with central passage (806).

Referring to Figure 22, there is shown another embodiment of a T-joint of my invention that is adapted to connect three duplex conduits. T-joint (820) comprises a body (822) having three couplings (824), (826) and (828) adapted to receive duplex conduits (830), (832) and (834) respectively. Within the body (822) of the T-joint (820) is a dual flow diverter (836) that is adapted to divert both central passage way flow and annular flow in the three duplex conduits joined to the T-joint. T-joint (820) could be used in position (242) illustrated in Figure 6 joining the header (16) to the faucet (12). This application of T-joint (820) will be used to describe its operation. Hot water from the hot water reservoir is received by T-joint (820) from central passage way (840) of conduit (834). Dual flow diverter (836) intake port (842) is tapered to accept the end of conduit (834) in a leak free relationship and diverts flow from central passage (840) into the dual flow diverter first discharge port (835) and subsequently into the central passage (844) of conduit (830). Discharge port (835) is tapered to accept the end of duplex conduit (830) central flow passage (844) in a leak free relationship. As illustrated in Figure 6, flow through central passage way (844) is destined to the closed faucet (12) where it is re-circulated into annular

passage way (846) of conduit (830). Flow through the annular passage way (846) is intercepted by the dual flow diverter (836) second intake port (850) and diverted so that it is discharged by second discharge port (852) into the annular passage way (854) of dual passage conduit (834).

Referring to Figure 6, flow through central passage (854) is destined to heater (100) where is its re-circulated back into conduit (832) annular passage way (860). Flow through annular passage way (860) is permitted to by-pass the dual flow diverter (836) by way of passage (862) and proceed into annular flow passage way (854) of conduit (834).

Referring now to Figure 23, there is shown an in-line coupler (870) adapted to connect co-axially two duplex conduits (872) and (874) respectively. Coupler (870) comprises a body (876) having a first coupling (878) adapted to receive conduit (872) and a second coupling (880) adapted to receive conduit (874). Within body (876) is a hollow connector (882) having a first tapered end (884) and a second tapered end (886) so as to receive the ends of central passage ways (888) and (890) in a leak free relationship. Annular flow from conduit (872) annular flow passage (892) passes around connector (882) through annulus (894) and into the annular flow passage (896) of conduit (894).

Referring now to Figure 24, there is shown a reducing adapter (900) of one embodiment of my invention. Reducing adapter (900) is adapted to co-axially connect a first duplex conduit (902) having a first diameter (904) with a second duplex conduit (906) having a second diameter (908).

Adapter (900) includes a coupler (910) that is configured to accept the end of conduit (902) and the end of conduit (906) while ensuring that there is continuous and leak free flow from annular passage (912) into annular passage (914) and from central passage (916) into central passage (918).

Refer now to Figures 25a and 25b conduits used in my invention may be required to pass through walls and bulkheads depending on the installation. Therefore, my invention includes a bulkhead fitting (920) that comprises a disc (922) made from a suitable resilient material. Disc (922) has a central opening (924) adapted to receive a conduit (926) in a tight fitting relationship so as to secure hold it. The disc (922) may be placed on either side of a wall. The disc has a plurality of apertures (928) to permit fastening to the wall by suitable fastening means.

Referring now to Figure 26, there is shown another hot water supply and space heating embodiment of the system of my invention (930) in a recirculation mode. This embodiment illustrates how duplex components can be integrated into a simplex system to retrofit an existing system into a more energy and water efficient system. Some of the components in this in this embodiment are similar to components shown in Figures 2,3 and 6 and so the same numbers will be used to identify these similar components in Figure 26. There is shown hot water reservoir (14) having outlet port (15) and simplex outlet conduit (40). Water is drawn into simplex conduit (41) through simplex elbow (43). Accumulator (108) is joined to the system by way of simplex T-joint (932). Water flows through simplex conduit (934) to specialized T-joint (936) of the type describe in Figure 20 which is adapted to connect simplex conduit (934) and simplex conduit (935) to duplex conduit (938). Hot water from the hot water reservoir (14) is directed up the central passage way (937) of duplex conduit (938) and into heater (100) by way of specialized T-joint (939) of the type described in Figure 22. Heater (100) is a space heater. Faucet (12) is closed and so hot water is re-circulated back into the annular passage (940) of conduit (938), through T-j oint (939) and T-joint (936) into simplex conduit (935) through simplex elbow (941) into conduit (942) and specialized T-joint (943) which is also described in Figure 20. Additional heater (101) may be valved into the system by way of duplex ball valve (944) to for additional space heating. Water is returned to reservoir (14) by way of simplex T-joint (948), pump (947), conduit (946), simplex elbow (949) conduit (950) simplex elbow (951) check valve (952) and simplex T-joint (953). Also illustrated in Figure 26, is cold water simplex pipe (66) connected to the faucet (12) and used to replenish water in the hot water reservoir through check valve (220).

Referring to figure 26, we further describe space heater (101). A typical space heater design may be adapted to the duplex nature of my invention (10) by means of a specialized tee (60,450, 520,540, 740,750) or any other specialized part, which can be used to separate the flows in a single duplex conduit into two or more separate simplex conduits directing water flow into the simplex radiator. Also the radiator may be produced in a manner wherein duplex pipe is attached directly to radiating fins, thereby eliminating the need for an adapter altogether. Incorporated with the space heater (101) may also be a fan or other device for forcing air past the radiating means. A

fan is used in order to enhance the efficiency of the heat transfer from the hot water to the air, or to the cold water from the warmer air if used as a chiller. A pump may also be used to regulate flow speed of the water thru the radiator. Also, the space heater may call upon the use of a duplex valve to switch flows to either. Any of these systems may be controlled via logic circuits or by manual control.

Figures 26a to 26e illustrates other embodiments of space heater (101) and the manner in which it is connected to the system.

In another embodiment of my invention, various components can be grouped together and advantageously molded and machined from a light-weight and inexpensive single block of suitable material for easy installation on a pre-existing hot water reservoir or heater. Referring now to Figure 27 there is shown what is referred to herein as"uni-block"manifold (1000) adapted for installation onto the top of a hot water heater or reservoir (14). The uni-block manifold (1000) is comprises of a single block of suitable material (1002). The conduits shown therein and described herein are machined into the block of suitable material. Couplings, pumps and thermometers can be easily installed on the block. Figure 27 illustrate the uni-block manifold (1000) in a recirculation mode. The uni-block manfold (1000) comprises a first coupling (1004) adapted for connection to the hot water outlet (1006) of the hot water heater (14). Pump (1008) draws re- circulating hot water (1015) from the water tank (14) and discharges it into the central passage way (1010) of duplex header (1012). Since the system is in are-circulating mode, that is, the faucet is closed ; the demand flow check valve (1014) is closed. Thermometer (1016) indicates hot water flow temperature at the tank outlet. Thermometer (1016) is connected logically (1018) to a controller (1020) that is adapted to control (1022) the operation of pump (1008) so that the system temperature may be controlled between desirable set points. Manifold (1000) further includes coupling (1024) adapted to connected duplex header (1012) to the manifold and direct simplex flow from the pump to the central passage way (1010). Return water (1030) from the annular flow path (1032) of duplex header (1012) is directed into return flow passage (1034) by flow diverter (1036). Check valve (1038) remains open during re-circulating flow so that there is communication between passage (1034) and the water tank inlet (1040) by way of passage (1042).

There is also included a pressure switch (1044) to sense system pressure that is connected logically

(1046) to the pump controller (1020) to maintain system pressure between desired set points.

There is also a second thermometer (1050) to measure the temperature of the return water stream from the header (1012). Thermometer (1050) is logically connected (1052) to the pump controller (1020) to maintain return water temperature between desired set points. The uni-block manifold (1000) further includes a coupling (1054) adapted to connect to a hot water tank water replenishment source by way of check valve (1056) which is closed during re-circulation.

Referring now to Figure 28, there is shown the uni-block manifold (1000) in demand mode that is, when the faucet is open and hot water is demanded from the hot water reservoir (14). The pressure differential across the system caused by the pressure drop from the open faucet causes demand flow check valve (1014) to open and re-circulation check valve (1038) to close. Pump (1008) continues to operate and may accelerate to compensate for the pressure drop sensed by pressure sensor (1044) logically connected (1046) to the pump controller (1020). Demand flow (1060) is drawn through check valve (1014) and directed by flow diverter (1036) into the annular flow passage (1032) of header (1012). Pumped flow (1062) continues to be directed by flow diverter (1036) into the central passage (1010) of header (1012). Check valve (1056) is open to permit replenishment water flow (1064) through coupling (1054) and into the hot water reservoir.

Referring to Figure 29a, there is shown another embodiment of the uni-block manifold of my invention wherein check valves (1038) and (1056) are replaced by single valve means (1500) comprising a single body (1502) having a profile as shown at (1503). The body is adapted to travel to and fro freely in passage way (1504). Figure 29a shows the valve when the uni-body manifold is in are-circulating mode. Body (1502) is forced by system pressure against the replenishing flow inlet thereby preventing the flow of replenishing fluid into the reservoir.

Referring to Figure 29b, when the system is in demand mode, the pressure drop across the uni- block manifold forces the body to the opposite end of the passage way thereby sealing the passage way against re-circulating flow and opening the passage way to replenishment flow. Ball (1011) in check valve (1014) may also be replaced by body (1506) identical to body (1502) Referring now to Figure 30, there is shown yet another embodiment of my invention providing hot or cold water recirculation for zone heating or chilling purposes and for use in buildings,

recreational vehicles, commercial vehicles and vessels. Figure 30 is modified from Figure 2, which is the hot water supply for consumption configuration of my invention, by removing those components associated to hot water demand flow. The zone heating configuration comprises a hot/cold water reservoir (1800) having an outlet port (1802) and an inlet port (1804). Re- circulating water pump (1806) draws water from the reservoir and discharges it into duplex header (1810) central passage (20) by way ofT-joint (130) of the type described in Figure 4. Flow (1812) is directed into the central passage of duplex header (1810) for distribution to a plurality of heating zones, shown in Figure 30 as (1814), (1816) and (1818). The configuration also includes accumulator (1822) to maintain a pressure in the system so as to suppress adapt to thermal expansion and prevent water hammer due to pressure fluctuations when zones are valved in.

Heating/chilling water is distributed by way of duplex conduits (1824) to heating zones through a plurality of distribution duplex T-joints (1826) and (1828) which are of the type described in Figure 22. Zone valves (1830) are located in line to permit and regulate hot/cold water flow into the zones and into hot/cold water radiators (1832). The zone valves may be remotely controlled by way of a zone thermostat or they may be manually operated. Hot/cold water is returned by way of annular flow paths in duplex conduits (1824) into simplex inlet conduit (1836) connected to inlet port (1804). Normally open check valve (1840) on simplex inlet conduit (1836) prevents back flow into the system from the reservoir. As well there is provided a temperature gauge (1842) and water replenishment line (1846) connected to the system by way of check valve (1848).

The replenishment line is also equipped with valve (1850) to isolate the line as necessary. As is obvious from Figure 30, the heating configuration of my invention further includes a plurality of elbow joints and connectors of the simplex and duplex type as described herein.

Referring now to Figures 3 la, 3 Ib and 31c there is shown yet another embodiment of my invention that is applicable to smaller water systems. Such systems may be found in recreational vehicles where the water heater or water chiller and the conditioned water reservoir are separated.

Figure 31 a shows such a system in a re-circulating mode. The system comprises a conditioned water reservoir (1400) connected to a replenishment source of water (1402) by way of a check valve (1404) and an isolation valve (1406). In the re-circulation mode the check valve (1404) is normally closed. Reservoir (1400) has an outlet (1406) to which is coupled the intake port (1407) a re-circulating pump (1408). Re-circulating flow from the pump discharge (1409) is directed into

the central passage (1410) of duplex conduit (1412) through specialized T-joint (1414) of the type described in Figure 19. Return flow from the annular passage way (1416) of duplex conduit (1412) is directed by T-joint (1414) into water reservoir intake (1418). Figure 31b illustrates the same system as Figure 3 la in a demand mode, when, for example, a hot or cold water faucet is opened. The pressure differential across the system caused by the open faucet causes a reversal of flow in annular flow pathway (1416) and demand water (1420) is drawn from the tank into T-joint (1414). Pumped water (14220 continues to flow in central passage way (1410) of duplex conduit (1412). Check valve (1404) is opened to provide a replenishment flow of water into the reservoir.

As illustrated in Figure 31c, the pump (1408) can be configured to rotate in an opposite direction by replacing T-joint (1414) with T-joint (1430) which is of the type described in Figure 4. In this configuration, re-circulating flow is drawn out of port (1418) and returned by way of port (1406).

Referring now to Figures 32a and 32b there is shown an adapter T-joint that is able to convert a simplex conduit T-fitting into a duplex conduit T-fitting. Simplex T-fitting (1500) comprises a body (1502) having a first (1504), second (1506) and third (1508) couplings that are adapted to receive the open ends of simplex conduits. The conversion apparatus comprises a generally T- shaped second body (1510) that is adapted for insertion into the simplex T-body (1502). The second body includes three tapered ends (1512), (1514) and (1516). These three tapered ends are adapted to receive a coupling ring (1520). The coupling ring fits over the tapered ends in a sealing engagement. The coupling ring comprises an outer spacer ring (1522) and an inner collar (1524) that fits over the tapered ends of the second body. The outer spacer ring is separated from the collar by spacers (1524). The face (1526) of the spacer ring is adapted to seal against the face of an outer end of a duplex conduit and face (1528) of the collar is adapted to seal against the face of the inner passage of a duplex conduit in a leak free relationship. In this way, annular flow from a duplex conduit attached to the body (1502) is directed through the annulus (1530) in the coupling ring and over the second body (1510) into the annulus of the co-joined duplex conduits. Flow through the central passage of a duplex conduit is directed through the central passage (1532) of the ring (1520) and into the central passage of body (1510) for distribution into the central passages of the co-joined duplex conduits.

In a similar manner, simplex ball valves, elbows, tees, crow feet, wyes, straight pipes, couplings, reducers, unions, and flanges may be converted into duplex configurations.

A person skilled in the art will understand that my invention can be used for chilling fluids as well as for heating fluids. The principles of simplex and duplex flow are the same and only a number of components need be changed. For example, the hot water reservoir may be a chilled water reservoir and space heaters can be exchanged for chillers. Whether the fluid circulating is hot or cold, the principles of operation of my invention remain the same. Therefore, although this description has much specificity, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given




 
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