DISTILLATION APPARATUS

Technical Field

The present invention relates to distillation apparatus and more particularly but not exclusively to water distillation apparatus to produce potable water from a water supply.

Background of the Invention

There are numerous methods and apparatus for producing potable water from waste water and/or saline. However these previous methods and apparatus are either expensive to operate due to their energy demands, and/or requires substantial capital investment.

Object of the Invention

It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

Summary of the Invention There is disclosed herein a distillation apparatus including: a heat exchanger having a first and a second path along which a fluid passes for transfer of heat therebetween, the heat exchanger having an inlet and an outlet for said first path, and an inlet and an outlet for said second path; a fluid delivery duct in communication with said first path inlet to deliver the fluid in liquid form to the second path inlet; an outlet reservoir communicating with the first path outlet to receive the liquid therefrom; a heater to raise the temperature of the liquid in said reservoir; a fluid compressor communicating with the reservoir to take the fluid in vapour form from said reservoir, said compressor also being in communication with the second path inlet to deliver compressed vapour to said second path inlet; and an outlet drain in communication with said second path outlet to drain liquid resulting from condensation of the vapour condensing to form liquid in said second path.

Preferably, said apparatus further includes a passage extending from said reservoir to provide for the drainage of at least part of the liquid in said reservoir. Preferably, said compressor is a fan. Preferably, said delivery duct includes a delivery reservoir.

Preferably, said apparatus includes an outlet for draining liquid from said delivery reservoir.

Preferably, said apparatus includes a primary inlet to provide for the delivery of liquid to said delivery reservoir. In an alternative preferred form said apparatus includes an outlet for draining liquid from said outlet reservoir.

Preferably, said heat exchanger includes: a plurality of stacked frames, each frame being of a rectangular configuration so as to have four sides, a plurality of baffles extending between two opposite sides of said four sides so that adjacent baffles define a passage extending between said opposite sides; a sheet material located between adjacent frames and covering the passages of the adjacent frames and providing for the transfer of heat between fluid passing between the passages of adjacent frames; a plurality of the passages of each frame include an entry passage portion, a generally central passage portion and an exit passage portion, with the generally central passage portion extending diagonally relative to said opposite sides; and wherein a plurality of the frames provide passages providing said first path, while other frames provide a plurality of passages providing said second path.

Preferably, in respect of each passage, arcuate passage portions join the entry passage portion and the exit passage portion to the central passage portion.

Preferably, said central passage portion extends at approximately 45° to said opposite sides.

Preferably, each of said opposite sides includes a first side portion and a second side portion, with the first side portions being located directly opposite each other, and the second side portions being located directly opposite each other and wherein in respect of each passage of said plurality of passages, the inlet portions extending from a first one of the first side portions, and the exit portions extending from the second side portion of the other opposite side.

Preferably, each side portion extends approximately half the length of the respective side.

Preferably, said entry portions and said exit portions extend generally normal to their respective side.

Preferably, said frames are arranged so that the central passage portions of adjacent frames are substantially perpendicular. Preferably, said sheet material is substantially moisture impervious.

In a further preferred form, said sheet material is sheet Mylar (Registered Trademark).

There is further disclosed herein a method for distilling a distilled liquid from a feed liquid, the method including the steps of: delivering a stream of the feed liquid to the first path of a heat exchanger; delivering the feed liquid from the first path to a first chamber that receives vapour of said feed liquid; taking the vapour from said first chamber and compressing the vapour; delivering the compressed vapour to a second path of the heat exchanger to provide for the transfer of heat from the vapour passing along said first path to the feed liquid passing along said first path; and allowing the vapour to condense in said second path to provide said distilled liquid; and delivering said distilled liquid to an outlet. Preferably, the method further includes delivering the feed liquid to a second chamber communicating with said first path, and draining feed liquid from said second chamber.

Preferably, the method further includes heating the feed liquid in said first chamber when required to aid in producing said vapour. Preferably, compressing the vapour is performed by a fan.

Preferably, said liquid is water.

Brief Description of the Drawings

Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a schematic sectioned side elevation of a distillation apparatus to distil potable water from recycled water and/or saline;

Figure 2 is a schematic side elevation of a modification of the apparatus of Figure 1;

Figure 3 is a schematic sectioned bottom plan view of the apparatus of Figure 2; Figure 4 is a schematic top plan view of the apparatus of Figure 2;

Figure 5 is a schematic parts exploded isometric view of a portion of a heat exchanger including frames and sheet materials to separate the frames;

Figure 6 is a schematic sectioned end elevation of portion of the heat exchanger of Figure 5;

Figure 7 is a schematic sectioned side elevation of portion of the heat exchanger of Figure 5;

Figure 8 is the schematic plan view of a frame employed in the heat exchanger of Figure 5; Figure 9 is a schematic end elevation of the frame of Figure 8;

Figure 10 is a schematic end elevation of the frame of Figure 8;

Figure 11 is a schematic end elevation of the frame of Figure 8;

Figure 12 is a schematic isometric view of a stack of the frames of Figure 8; and

Figure 13 is a schematic top plan view of the stack of Figure 12.

Detailed Description of the Preferred Embodiments

In Figures 5 to 13 of the accompanying drawings there is schematically depicted a heat exchanger 10. The heat exchanger 10 includes a plurality of heat exchanger frames 12 that are arranged in a stack 13, with adjacent frames separated by a length 14 of sheet material 15, as best seen in Figure 5. The length 14 is arranged along a serpentine path so as to provide a plurality of pockets 16. Located in each pocket is a respective one of the frames 12. The material 15 is water impervious and is preferably plastics material such as Mylar (Registered Trademark).

In this embodiment each of the frames 12 is of a rectangular configuration and more particularly a square configuration as best seen in Figure 8. The stack 13 is of a parallelepiped configuration as best seen in Figure 12.

Each frame 12 is generally flat (generally planar) and in this embodiment is square in configuration. Each frame 12 has four sides 16, 17, 18 and 19, The sides 17 and 19 are generally flat strips 21 and do not have any apertures. The opposite sides 16 and 18 each include a first side portion 22 or 23, and second side portions 24 or 25. The side portions 23 and 24 are also generally flat strips and do not have any apertures, while the side portions 22 and 25 each have a plurality of apertures 26 or 27.

Extending between the side portions 22 and 25 is a plurality of baffles 28 that are essentially strips or flanges, with a passage 29 being located between each adjacent pair of baffles 28. The baffles 28 are arranged so that each aperture 26/27 is aligned with a respective one of the passages 29. Preferably at least some of the passages 29 are divided longitudinally by a dividing baffle 30. Accordingly in operation a fluid can enter via one of the apertures 26/27 and flow along the respective passage 29 to exit via the other aperture 26/27. The passages 29 of adjacent passages 29 are separated by the length 14. Support members 31 extend between the sides 17, 18, 19 and 20 to aid in supporting the

baffles 28 and 30 in the positions illustrated. In that regard it should be appreciated the support members 31 do not block the passages 29.

Each of the passages 29 includes a first passage portion 32 that extends from the side portion 22. Each passage 29 further includes a second passage portion 33 that extends from the side portion 25. In that regard the passage portions 32 and 33 extend generally normal form the respective side portions 22 and 25.

Each passage 29 further includes a diagonal generally central passage portion 34 that may be divided longitudinally by a respective one of the baffles 30. Each passage portion 34 is joined to its respective passage portions 32 and 33 by arcuate passage portions 35. As is best seen in Figure 11, each diagonal passage portion 34 extends at approximately 45° to the opposite sides 16 and 18. Accordingly at the passage portions

34 the baffles 28 and 30 also extend at approximately 45° to the sides 16 and 18.

The side portions 22 and 25 are provided with projections 36 that would aid the mounting thereto of ducting when the frames 12 are arranged in the stack 13. Preferably the sides 16 and 18 are provided with ridges 37 that are engaged with a corresponding longitudinal recess 38 of the next adjacent frame 12 to provide for the alignment of the frames 12 and there securing in a stack 13.

As best seen in Figure 7, each frame 12 has a recess 38 within which the length

14 is located to be securely attached to the frames 12 by engagement of the ridges 37 on the recess 38.

The stack 13, as best seen in Figure 12 has four side faces 40 to 43, with the faces 41 and 43 having strips 21 so that they are essentially closed off. The faces 40 and

42 have the apertures 26 and 27 with the passages 29 extending therebetween so that fluid may flow between the faces 40 and 42. The stack 13 is particularly formed by a plurality of the frames 12, that are stacked as follows. Each alternate frame is arranged in the orientation as shown in Figure

11. Every other frame is arranged with the frame 12 as shown in Figure 11 but rotated through 180° about the transverse axis 44. Accordingly the stack 13 provides four face portions, 45, 46, 47 and 48. The face portion 45 has apertures 26 as does the face portion 46. The face portions 47 and 48 have apertures 27. The passages 29 extending from the apertures 26 of face portion 46 communicate with the apertures 27 of the face portion 48.

Simultaneously the passages 26 of the face portion 45 communicate with the apertures 27 of the face portion 47. Accordingly the diagonal passage portions 34 of adjacent frames

12 are generally perpendicular.

Because the length 14 is interposed between adjacent frames 12, the passages 29 of adjacent frames 12 do not communicate in respect of fluid flow however there is transfer of heat between adjacent passages 29 of adjacent frames 12. For example, a fluid could enter the apertures 26 of the face 46 and travels through the passages 29 to exit via s the apertures 27 in the face 48, while a fluid entering the apertures 27 of the face 47 would flow via passages 29 to the apertures 26 of the face 45, to provide for the transfer of heat from fluid passing from face portion 46 to face portion 48 to fluid passing from face portion 47 to face portion 45.

The passages 29 extending between the face portions 46 and 48 provide a first io fluid path, while the passages 29 extending between the face portions 45 and 47 provide a second fluid path.

The face portions 45, 46, 47 and 48 are generally planar with the apertures 26 and 27 arranged in linear rows. The rows of face portion 45 are offset relative to the rows of face portion 46, while the rows of face portion 48 are offset relative to the rows of face I ₅ portion 47.

As is best seen in Figure 13, the diagonal portions 34 of adjacent frames 12 are generally perpendicular. Marked in Figure 13 are two diagonal passage portions 34, as can be seen they are generally perpendicular.

In Figure 1 of the accompanying drawings there is schematically depicted a 20 distillation apparatus 50. Typically the apparatus 50 is to produce potable water by distilling recycled water and/or saline.

The apparatus 50 includes a heat exchanger 10, as described with reference to Figures 5 to 13. However the heat exchanger could also be a heat exchanger described in any one of USA Patents 6829900, 6935132 or 5829513, or any one of the heat exchangers 2 ₅ described in Australian Patent Applications 2004215315 or 2005266840.

The heat exchanger 10 as previously described has passages 29 extending from face portion 46 to face portion 48, providing a first fluid path, and passages 29 extending from face portion 47 to face portion 45 providing a second fluid path. The face portion 46 provides an inlet for the first path and the face portion 48 providing an outlet for the 30 first path. The face portion 47 provides an inlet for the second path while the face portion 45 provides an outlet for the second path.

Communicating with the face portion 46 is a delivery duct in the form of a reservoir 51 that provides for the delivery of water to be delivered to the passages 29 of the first path. The face portion 48 provides an outlet for the first path and receives the

3 ₅ water from the passages 29 extending from the first face 46. Water leaving the face

portion 48 is received by the reservoir 52, with the water having a water level 53, Preferably the reservoir 52 has a heater 54 that may be activated when required, particularly when the apparatus 50 is in a "start-up" mode. The reservoir 52 also contains vapour (steam) of the liquid in the reservoir 52, with the vapour being delivered to a compressor in the form of a fan 55. The fan 55 delivers compressed vapour to a duct 56 extending to a hollow housing 57 providing a chamber 58 communicating with the face portion 47. The face portion 47 provides an inlet for the passages 29 of the second path, the second path extending to the face portion 45 that provides an outlet for the second path. The vapour in the chamber 58 enters the passages 29 of the second path and passes therealong to a reservoir 59 just downstream of the face portion 45. Thus the reservoir 59 receives the water that condenses in the passages 29 extending from the face portion 47 to the face portion 45. The condensed water (potable water) is then drained by means of a duct 60 communicating with a restriction valve 61 and a solenoid valve 62.

The apparatus 50 includes an inlet assembly 63 including a delivery pipe 64 that delivers water via a check valve 65 to a solenoid valve 66. The valve 66 communicates with a filter 67 via a float valve 68. The float valve 68 includes a float 69 that is operatively associated with the water level 53 of the reservoir 52. The float valve 68 governs the delivery of filtered water to the primary inlet 70, that communicates with the reservoir 51 via a restriction valve 71. The reservoir 51 also has a drain 72 that provides for the removal of waste water therefrom to provide for the introduction of further treated water to the heat exchanger 10. The waste water flows down the passages 29 under the influence of gravity, as it is heavier than the water flowing in the opposite direction.

In operation of the above described apparatus 50, water in the reservoir 51 is delivered thereto via the primary inlet 71. The water in reservoir 51 moves through the passages 29 to reach the reservoir 52 until the water level 53 reaches a desired level. The heater 54 is activated at start up to cause the production of water vapour (101 ⁰ C). The water vapour (steam) is taken via the fan 55, compressed and delivered to the chamber 58. The water vapour then passes along the passages 29 to exit via the face portion 45 as water, having condensed to distilled water, to be received by the reservoir 59. This distilled water is drained via operation of the valves 61 and 62. Accordingly the water and vapour (steam) passing along the second path heats (boils) the water passing along the first path to thereby deliver to the reservoir 52 heated water that again will evaporate. As water is taken from the apparatus 10, further water is added via the inlet assembly 63.

Waste water is also taken via the drain 72 to ensure that, for example if saline is used, the water does not become too salty.

The process continues, with heat being added via way of operation of the fan 55.

More particularly the fan 55 takes vapour from the reservoir 52 (at a temperature of about 101°C) and delivers it to the chamber 58 after compression, with the vapour in the chamber 58 having a temperature of about 103°C. If so required, the heater 54 may also be activated apart from initial "start up".

Contaminated water (such as the saline) flows backward along the first path to accumulate in the reservoir 51 from where it is drained at the lower portion 72 thereof. In Figures 2 to 4 there is schematically depicted a modification of the apparatus

50. In this embodiment the apparatus 50 has an inlet assembly including a column 75 that receives the water to be treated so as to maintain the desired water level 53. The inlet assembly 75 further includes a float operated valve 76 that maintains the water level 53, with a restriction valve 77 and a solenoid valve 78 receiving water from a one-way valve 99, communicating with an inlet pipe 100.

In this embodiment the drain 72 communicates with two central passages 73 (of the passages 29) to provide for the discharge of contaminated (heavier) water from the apparatus 10.

Because the waste water is heavier it flows from the chamber 52 into the passages 73.