Technical Field of the Invention

The present invention relates to a system for pumping a liquid containing particles or solid substances, where the particles or solid substances is not intended to be pumped through the liquid pump used for the pumping operation, avoiding exposing said particles or solid substances for moveable parts of the pumps or exposing the same for high liquid velocities. In particular, but not exclusively, the system is suitable for pumping fish in water, in particular, but not exclusively living fish. The particles may also other type of food.

In particular, the invention relates a method and system for pumping particles contained in a liquid, preferably living fish in water but not exclusively, from a liquid volume containing the particles to a receiving unit through associated one or more closed pipelines, using at least one pump; where liquid and particles are drawn through a pipeline from the liquid volume to a chamber for establishing a sub- pressure in the chamber by means of one or more pumps; and where liquid and particles are transported from the chamber through one or more closed ducts or pipelines to a receiving unit contained in a liquid, preferably living fish in water.

Background for the invention

When pumping fish there is a need for a system enabling pumping of a continuous flow of water from the suction side of the pump, pumping water and fish for delivery of water and fish at a higher level, and at the same time obtaining a large total lifting height and proper and adequate lifting capacity on the suction side without exposing the fish for excessive water velocities as in an ejector pumping system. Moreover, the system must be able to be positioned above the water for example in a temporary fishing cage containing fish for transfer or the water in a well boat for transporting for example fish to a abbatoir, the only part of the pumping system being submerged just below the water level being an inlet funnel for suction of water.

There exit many prior art solutions for pumping fish, but all of them differ from the present invention in that they cannot combine functions as being arranged above water; large total lifting height, appropriate proper lifting height on the suction side; and continuous water flow from inlet to outlet without exposing the fish for large and detrimental water velocities or movable pumping parts, also when pumping large fish. US 4,551 ,042 discloses a pump for pumping fish where water is extracted and air is added at a location in the pumping system higher than the initial air injection point, thereby excluding a certain percentage of water, whereupon the efficiency is not only increased, but variable control capabilities are achieved. According to this solution, the fish is lifted up via a transport pipe to a chamber by means of formation of a sub-pressure in the transport pipeline, the pump comprises a pump for gas/air and pumps for liquid/water, where air and water is injected at a pressure through openings into the lower part of the pipe. Air is also injected in an upper air supply ring, such that the fish is transported up in party air born state through the transport pipe to a height above water level.

Another prior art method for pumping fish is described on EP 0352941 , the method comprising use of a fish pumping device where a chamber receives a mixture og water and fish via an inlet orifice when the chamber is subjected to an under-pressure, and where the mixture of water and fish is transported out of the chamber along to the outlet, when the chamber becomes subjected to an overpressure.

Other known prior art methods are disclosed in the following listed patents or patent application: EP 1 179508; WO 2010/082834; US 9,01 1 ,680 B; GB 2 498 667 B; NO 394301 B; NO 394302 B; NO 303841 B; and US 4,551 ,042 B.

Summary of the Invention

An object of the present invention is to provide a device for pumping liquid and particles, preferably water and fish, where liquid and particles float continuously in a pipeline from inlet to outlet, without moving the particles through a liquid pump with moveable parts.

Another object of the invention is to provide a device for pumping a liquid and particles, preferably water and fish, where the velocity of the liquid flow may be maintained at a velocity that does not cause any damage to the particles.

A further object of the invention is to provide a device for pumping liquid and particles, preferably water and fish, where the suction side has sufficient lifting height so that the pumping device may be positioned at a certain height above the water surface, for example onboard a well boat or a fishing vessel, and at the same time permitting that the inlet end for liquid and particles to be positioned just below the water surface.

Yet another object of the invention is to provide a device for pumping liquid and particles, preferably water and fish, requiring as small space or foot print and still providing sufficient lifting height to transport liquid and particles to a plant positioned a distance apart or at a large height above the water surface.

Another object of the invention is to provide a device for pumping a liquid and particles, preferably water and fish, with sufficient capacity so that the water flow obtains a velocity sufficient to catch living fish without allowing the fish to

unintentionally escape or swim away from the suction inlet, also when using pipes with large pipe diameter, thus allowing pumping of large fish.

According to the invention, the objects are achieved by a solution more clearly defined by the independent claim, while embodiments, variants and alternatives are defined by the dependent claims.

According to a first embodiment of the invention, it is provided a method for pumping particles contained in a liquid, preferably living fish in water, from a liquid volume containing the particles to a receiving unit through associated one or more closed pipelines, using at least one pump; where liquid and particles are drawn through a pipeline from the liquid volume to a chamber for by establishing a sub- pressure in the chamber by means of one or more pumps; and where liquid and particles are transported from the chamber through one or more closed ducts to a receiving unit. The liquid and particles are delivered from the chamber into an ejector and from the ejector to the receiving unit through a pipeline by means of a pump pumping water through the ejector and into duct for formation of a sub-pressure at the ejector and for providing a required liquid flow through the duct, and by connecting the suction side of the pump to a separate chamber connected to the chamber via an outlet with openings that are smaller than the particles for supply of only liquid and gas from the chamber into the chamber, the ejector and the pump together forming a sufficient sub-pressure with a subsequent over-pressure so that sufficient volume of liquid and particles may be drawn from the liquid volume through the closed duct to the chamber, and from the chamber through the ejector and the duct to the receiving unit, preventing the particles from passing through the pump.

One or more compressors may be used for supply of pressurized gas delivered to a distribution chamber, allowing the gas to ascend upwards in the liquid via openings in the chamber wall, drawing particles through the chamber past the outlet and into the ejector.

Moreover, the pump may pump gas in addition to liquid, so that the pump evacuates gas from the chamber and the volume that is substituted by liquid, drawn up from the liquid volume. According to one embodiment, a rotating sieve or band sieve may be used in association with the outlet to the chamber in order to transport the particles past the inlet towards the ejector.

The sieve may preferably be cleaned by a liquid jet forcing liquid in direction from the chamber into the chamber in order to force particles away from the outlet and into the ejector.

According to an alternative, nozzles forming a part of the ejector may be used, allowing a part of the flow of liquid out of the ejector to pass through the outlet for forcing particles away from the outlet and into the ejector.

According to another embodiment, the particles may be shielded from the liquid flow out of the ejector by means of a sieve or filter at least until the liquid velocity out of the ejector has dropped downstream of the ejector to a level where said flow does not harm the particles.

According to the invention, it is also provided a system for pumping particles contained in a liquid, preferably living fish in water, comprising a pump; a suction line arranged between the pump and a liquid volume containing the liquid and the particles to pumped; a receiving unit, and a pipeline for transferring the pumped liquid and particles. An ejector is arranged downstream of the pump, an inlet of which being arranged in fluid communication with an outlet of the pump and with a device for formation of a sub-pressure at inlet of the ejector, providing a required liquid flow through the duct, said device being a separate chamber in fluid

communication with chamber via an outlet with openings that are smaller than the particles for supply of only liquid and gas from the chamber into the chamber, enabling both the ejector and the pump together to form a sufficient sub-pressure with a subsequent over-pressure at the outlet of the ejector so that sufficient volume of liquid and particles may be drawn from the liquid volume through the closed duct to the chamber, and from the chamber through the ejector and the duct to the receiving unit, preventing the particles from passing through the pump.

According to one embodiment of the system, the suction side of the pump may be connected to the chamber at the bottom of the chamber, and that outlet is positioned at the upper end of the chamber, so that gas mixed with the liquid will ascend upwards and back into the chamber through the outlet, while liquid is drawn downwards in the chamber and into the pump. The suction side of the pump may also be connected to an external supply of liquid.

The suction side may be connected to both the chamber and an external supply, where the connection may be completely opened and closed by means of a valve on the supply line and a valve on the connection to the chamber, said valves preferably being controlled so that it is a least flow resistance in the connection line to the chamber, until the outlet becomes partly or completely clogged by particles, and then it will be lower flow resistance in the external supply until gas delivered by the compressor draws away said particles when the gas ascends upwards through the liquid column in the chamber.

An outlet is arranged at the top of the chamber, having a controllable opening for gas with a non-return valve or check valve, configured to close at a sub-pressure in the chamber, and in case of build up of gas with overpressure at the top of the chamber the gas will force it way out of the chamber through the outlet, and by controlling or adjusting the opening of the outlet, sufficient overpressure will be maintained at the top of the chamber to force or press liquid and particles to the receiving unit.

The gas pressed out through the outlet may be directed to the distribution chamber for supply of additional gas at the bottom of the chamber. The outlet (9) may be provided with a third line with adjustable or controllable opening and a valve for allowing superfluous gas to escape out of the system, and wherein the valve may be mechanically adjusted or controlled for opening at a certain pressure, controlled manually or automatically by a sensor measuring the pressure or liquid level inside the chamber.

The compressor may be provided with two outlets, each with a valve where one of the valves being associated with the distribution chamber and the other with the ejector, so that by closing valve on the outlet from the distribution chamber and supplying pressurized gas from the compressor into the ejector, a sub-pressure is formed at the ejector, emptying the closed duct, the chamber and the chamber for gas, said gas being substituted by liquid drawn up from the liquid volume.

A non-return valve or check valve may be arranged in the closed duct or duct, closing if the flow of liquid and particles is moving in wrong direction from the duct to the liquid volume, and opens when the liquid flow moves in opposite direction.

According to another embodiment of the invention, it is provided a system for pumping particles contained in a liquid, preferably living fish in water. The system comprises a liquid volume containing the particles; one or more closed ducts from the liquid volume to a chamber for receipt of liquid and particles by establishing a sub-pressure in the chamber; one or more pumps for supply of gas and liquid; one or more compressors for supply of pressurized gas; and one or more closed ducts for transport of liquid and particles from the chamber to a receiving unit.

The chamber is provided with an outlet for liquid and particles into an ejector and from the ejector to a closed duct ending at the receiving unit; and a distribution chamber into which pressurized gas is supplied from the compressor(s), the gas ascending upwards in the liquid via openings in the chamber wall; and a pump pumping water through the ejector and into duct for formation of a sub-pressure at the ejector and for providing a required liquid flow through the duct, the suction side of the pump being connected to the chamber so that the volume of liquid supplied to the pump is drawn from the liquid volume; the chamber being connected to the chamber via an outlet with openings that are smaller than the particles for supply of only liquid and gas from the chamber into the chamber, so that the gas ascend vertically in the chamber, the ejector and the pump together forming a sufficient sub- pressure with a subsequent over-pressure so that sufficient volume of liquid and particles may be drawn from the liquid volume through the closed duct to the chamber, and from the chamber through the ejector and the duct to the receiving unit, preventing the particles from passing through the pump.

According to one embodiment, the pump may pump gas in addition to liquid, so that the pump evacuates gas from the chamber and the chamber that is substituted by liquid drawn up from the liquid volume.

Short Description of the Drawings

An exemplary embodiment of the invention shall in the following be described in further detail, referring to the accompanying drawings, wherein:

Figure 1 shows schematically, partly in vertical section, an outline of an exemplary embodiment of the invention for pumping fish from a cage to a well onboard a well boat;

Figure 2 shows schematically in an enlarge scale a vertical section through an exemplary embodiment of a pump according to the present invention;

Figure 3 shows schematically, partly in vertical section, an outline of a second exemplary embodiment according to the invention for pumping fish from a cage to a well onboard a well boat;

Figure 4 shows schematically in an enlarge scale a vertical section through a second exemplary embodiment of a pump according to the invention;

Figure 5 shows schematically, partly in vertical section, through a third exemplary embodiment of a pump according to the present invention; and

Figure 6 to 8 show schematically an outline of a second exemplary

embodiment of a pump according to the invention. Detailed Description of the Exemplary Embodiment disclosed in the Drawings

The following description of the exemplary embodiment refers to the

accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to various forms of pumping systems and pumps used for pumping water and fish. It should be appreciated, however, that the referenced pumping system may also be used for pumping other mixtures of a liquid and a substance, or particles or soft or solid bodies without deviating from the inventive idea.

Reference throughout the specification to "one embodiment" or "an

embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout the specification is not necessarily referring to the same embodiment.

Moreover, the arrows in the drawings indicate the direction of flow and movement through the system and the direction of rotation with respect to direction of flow.

Figure 1 shows schematically, partly in vertical section, an outline of a first exemplary embodiment of the invention for pumping fish from a cage to a well onboard a well boat, while Figure 2 shows schematically in an enlarge scale a vertical section through an exemplary embodiment of a pump according to the present invention. As indicated in the Figures, water and fish 2 (particles) is pumped up from a well 1 in the direction of the arrows and delivered to a tank or container or the like 16.

As indicated in Figure 1 and 2, the pumping plant comprises a hose with a suction funnel 3, where the end of the hose provided with the funnel 3 is submerged into the upper layer 20 of a liquid volume 1 containing the fish 2. The opposite end of the hose with the funnel 3 is connected to a first chamber 4. In association with the first chamber 4 a distribution chamber 1 1 is arranged, the interface plate between the first chamber 4 and the distribution chamber 1 1 being provided with a number of small holes or apertures for supply of air or a gas in the form of small bobbles to the chamber 4. This distribution chamber 1 1 is connected to a compressor 12, delivering pressurized gas to the distribution chamber 1 1 and hence to the firs chamber 4 through the small openings or apertures. The first chamber 4 extends vertically upwards to an outlet with a non-return valve or check valve 14, where liquid and particles 2 pass through the valve 14 and into an ejector 7 and then further into a pipeline 15, extending from the outlet of the ejector 7 and to a well, tank or a container 16. The check valve 14 opens up when the pressure in the first chamber 4 is larger than the pressure in the ejector 7 and closes when the pressure in the first chamber 4 is lower than the pressure in the ejector 7. The check valve 14 prevents in this manner liquid and particles from returning back from the pipeline 15 and downwards into the liquid volume 1 .

On top of the first chamber 4, an outlet 9 is provided, the outlet 9 being provided with an associated valve 10 for evacuating air trapped at the top of the first chamber 4, while at the same time the valve 10 closes when an under-pressure is formed in the first chamber 4, preventing that false air is drawn into the first chamber 4. If possible the outlet 9 is connected to a point on the pipeline 15 where the pipeline ascend upwards toward the outlet , allowing air to be drawn with the liquid flow and out of the pipeline 15, into the tank 16.

In the upper part of the first chamber 4, a liquid outlet 6 is provided for transfer of liquid to an outer chamber 5, the outlet 6 having openings or apertures that is smaller tan the smallest particles 2 to be pumped, thus preventing said smallest particles to enter into the outer chamber 5.

The outer chamber 5 is given such height that air that is drawn with the water into the outer chamber 5 ascends up and back into the first chamber 4 through the outlet 6, at the same time as the liquid is drawn downwards and into the pump 13. In this manner the suction side of the pump 13 contributes to filling of liquid in the first chamber 4, and during operation, to parts of the flow of liquid and particles 2 in the first chamber 4.

The pump 13 is a liquid pump of desired type, such as a positive pressure pump or a centrifugal pump with a non-return valve or check valve, where the pump 13 sealed when it is not in operation, such that the liquid does not flow back or return through the pump 13 and back into the first chamber 4.

The liquid is pumped through the pump 13 and into the ejector chamber 8 and further through the ejector 7 and into the pipeline 15. When the first chamber 4 is to be filled with liquid, there is no liquid in the pump 13 or in the ejector 7. It will then be the lowest pressure in the first chamber 4. The non-return valve or check valve 14 will the be closed, such that the pump 13 will form a sufficient sub-pressure in the first chamber 4 in order to lift liquid and particles 2 up from the liquid volume 1 through the hose with suction funnel 3. When the liquid level has come up to the pump 13, then the compressor 12 may be started. The compressor 12 forces the air into the distribution chamber 1 1 , so that air is supplied to the bottom of the first chamber 4. When this air ascends, it will function as a mammoth pump where the ascending air sucks or draws water up through the chamber 4.

Simultaneously the pump 13 pumps liquid into the antechamber 8 and from the antechamber 8 through the ejector 7, such that the ejector 7 forms an further pressure drop in the pipeline 15 at the ejector 7, and a corresponding pressure increase in the pipeline downstream of the ejector 7. In this manner both the pump 13, the mammoth pump and the ejector 7 contribute to a liquid flow of 200 to 300 liters per second and a lifting height in the order of 15 to 20 meters, in spite of the first chamber 4 having a limited height of 2.5 meters, and without causing any increase in liquid velocity in the ejector 7 that may cause damage or injury to the particles 2.

At the exit of the pipeline 15, the flow of liquid and particles 2 is led into a receiving unit 16, where the particles 2 are transported for further storage or processing.

Figure 3 shows schematically, partly in vertical section, an outline of a second exemplary embodiment according to the invention for pumping fish from a cage to a well onboard a well boat, while Figure 4 shows schematically in an enlarge scale a vertical section through a second exemplary embodiment of a pump according to the invention. . As indicated in the Figure, water and fish 2 (particles) is pumped up from a well 1 in the direction of the arrows and delivered to a tank or container or the like 16.

Figure 3 and 4 disclose an alternative embodiment of the invention n. This alternative embodiment differs from the embodiment disclosed in Figures 1 and 2, in that the pump 13 is connected to an external liquid supply 19 in addition to the connection to the outer chamber 5. The supply of liquid is controlled by means of a valve 17 on the external supply line 19 and a valve 18 on the supply from the chamber 5.

The external supply 19 is used for example for cleaning of the system with pure or clean water, filling of water at start-up and operation of the ejector 7 in those cases where particles 2 may have a tendency to clog the outlet 6.

When the external supply 19 is connected to the liquid volume 1 , the system may be operated with a valve 17 partly open and the valve 18 completely open. The pump 13 will then draw liquid supply with lowest flow resistance, so that if the outlet 6 becomes more or less clogged, then the least flow resistance will be in in the external supply 9. When the flow of air and liquid then flowing in the chamber 4 has cleaned the outlet 6, the pump 13 will again draw water from the external chamber 5, since the valve only will be partly open and function as a flow resistance in the external supply 19.

Figure 5 shows schematically, partly in vertical section, through a third exemplary embodiment of a pump according to the present invention. The Figure shows yet another exemplary embodiment that differs from the previously described embodiments in that fluid out of the outlet 9 is fed to the distribution chamber 1 1 for increase of air supply to the bottom of the first chamber 4. The outlet 9 is in addition connected to a valve 21 that may open a third line for addition of free air when the air at the top of the first chamber 4 obtains a certain increase in pressure or when a certain liquid level is obtained. The valve 21 may be controlled so as to open at a certain over-pressure. This occur when a larger build-up of air at the top of the first chamber 4 is formed, said air then obtaining an increase in pressure when the passage for the liquid below the pocket of air is narrowing in and the liquid is forced against the pocket of air.

Figure 5 shows also a further embodiment, where the gas from the

compressor 12 is directed either to the distribution chamber 1 1 or to the ejector 7. This is obtained by providing the compressor 12 with first line to the distribution chamber 1 1 that may be closed and open by a valve 22 and a second line 24 communicating with the ejector 7, that may be closed and opened by a valve 23. The valves 22,23 may be controlled manually or by a sensor sensing the liquid height in the chamber 4.

This function is used when the system is in progress of filling liquid. In such case the valve 22 is closed and the valve 23 is opened, while the compressor delivers pressurized gas into the ejector 7, creating a sub-pressure evacuating gas from the first chamber 4 and sucking up liquid from the liquid volume 1 and into the first chamber 4.

Figure 6 to 8 show schematically an outline of a second exemplary

embodiment of a pump according to the invention. This second exemplary embodiment differs from the first exemplary embodiment in that the outlet 6 for liquid to an outer chamber 5 is configured as a rotating sieve (ref. Figure 6) or a rotating bans sieve (ref. Figure 7), powered by a separate motor 28.

At the inlet to the ejector 7, a flushing unit 25 is arranged, forcing water through an outlet 6 from the side facing the chamber 5 and into the chamber 4. A closed wall 26 guides the particles and the liquid flow delivered from the flushing unit 25 into the ejector 7. The particles that follow the outlet when rotating, is drawn to the flushing unit 25 where the particles 2 are forced away from the outlet 6 by the liquid flow from the flushing unit25 and in such manner is fed to the inlet of the ejector 7. When the liquid has passed through the outlet 6, the liquid is pumped through the pump 13 and onto the antechamber 8 and from the antechamber into the ejector 7.

A sieve 27 shields the particles 2 from the strong and hard water flow coming out of the ejector 7 until the particles 2 and the water flow out of the ejector 7 are mixed in the pipeline 15 so far downstream of the ejector 7 that the water velocity out of the ejector 7 has been reduced to a level that does not cause any harm or damage to the particles 2.

According to one embodiment, the compressor 12 forces air into the distribution chamber 1 1 , such that air is introduced into the chamber 4. The air is mainly supplied for moving the particles away from the outlet and into the ejector 7. It is of importance that the system is configured in such that sufficient sub-pressure is established at the inlet to the ejector 7. Moreover, it is also important that the chamber is formed and configured in such way that the air ascends upwards in the chamber 4, ending at the inlet to the ejector 7. If the ejector 7 creates an increased sub-pressure 4, the ejector 7 will contribute to increased flow of liquid and particles 2 into the chamber 4. A part of the liquid flow will pass through the pump 13, while the remaining part of the liquid flow will enter at the suction side of the ejector 7. If a volume of air corresponding to the remaining part of the liquid flow is supplied, air will be lighter than the liquid and hence will be drawn into the ejector 7 instead of water. The system will then adjust itself down again until the flow of water and particles 2 entering the chamber 4 correspond to the liquid flow passing through the pump 13, while supplied air is drawn towards the ejector 7 instead of entering the pump 13.

Without supply of gas, only the particles 2 floating or sinking will be fed to the ejector 7, if the ejector is positioned at the top of the chamber 4 for floating particles 2, or at the bottom of the chamber 4, if the particles 2 sink. The particles 2 must then be much larger or lower density than the liquid, so that the particles when I the chamber 4 will be able to leave the water flow due to own weight or buoyancy. If not, the liquid flow will feed the particles 2 forward until the particles are forced against the outlet(s), and after a while clog the outlet(s).

In such latter case it may be necessary to use for example a rotating sieve 30 as outlet 6, moving the particles 2 forced against the outlet 6 towards the inlet of the ejector 7 due to the rotation of the sieve 30, ref. the arrows in Figures 6 and 7. As shown, while the particles and the liquid flow is in a direction to the left in the drawing, the direction of rotation of the rotating sieve is a clockwise direction. It should be noted that the embodiment disclosed in Figures 6 and 7, i.e. an

embodiment with a rotating sieve 30, supply of gas/air may be superfluous. Not with- standing the above, it should be noted, however, that the disclosed embodiment may also function in the intended manner even if a gas is supplied.

The embodiment disclosed in Figures 6 and 7, i.e. use of a rotating sieve, differs from the embodiments disclosed in Figures 1 to 5 in that the outlet 6 for supply of a liquid to the outer chamber 6 is configured or formed as a self-cleaning or rinsing sieve. The sieve may be ion the form of a rotating, cylindrically shaped sieve 30 or a rotating, band sieve, either being driven by a separate motor 28 (only indicated in Figure 8).

At the inlet to the ejector 7, one or more one or more nozzles 25 forcing liquid through sieve or filter 30 out through the outlet 6 from the side facing towards the chamber and into the chamber 4. Particles 2 following the outlet 6 when rotating, will be drawn towards the nozzles 25 where the particles are forced away from the outlet 6 by the flow of liquid out of the nozzles 25, and hence into the inlet of the ejector 7. A closed wall 26 guides the particles and the flow of liquid from the nozzles 25 into the ejector 7.

As shown in Figure 8, a sieve 27 protects the particles 2 against the tough and hard water flow out of the ejector 7, until the particles 2 and water flow out from the ejector are mixed downstream in the pipeline 15, such mixing occurring at a distance downstream of the outlet of the ejector 7where the velocity has decreased to a level that does not cause any harm to the particles.