WO1981002729A1

WO1981002729A1 - Arrangement for passing a first liquid close to,but without mixing it with a second liquid,for example an arrangement for sea water desalination

Info

Publication number: WO1981002729A1
Application number: PCT/SE1981/000076
Authority: WO
Inventors: F Torberger
Original assignee: F Torberger
Priority date: 1980-03-24
Filing date: 1981-03-10
Publication date: 1981-10-01
Also published as: CH653906A5; NO813929L; JPH049576B2; IT8148078A0; ES501171A0; NO152506B; SE419699B; AU544645B2; FR2478616B1; BR8107945A; DE3140614T1; GB2082927A; NO152506C; GB2082927B; AU6924181A; JPS57500323A; HK989A; DE3140614C2; ES8202489A1; IT1144483B

Abstract

An arrangement for permitting a first liquid to flow close to a second liquid, but without being intermixed therewith, comprises a first plurality of plates (11) and a second plurality of plates (12), which are located between plates in the first plurality of plates but spaced therefrom by means of separating pieces (13). Each separating piece (13) comprises a frame (130) about plate-shaped plane-parallel partial pieces, viz. an outer porous and hydrophobic plastic diaphragm (21), an intermediate distance network (22) of plastic and an outer thin plastic foil (23). The frame (130) includes infeed holes (1301) for air and outfeed holes (1302) for water. The voids of the plastic diaphragm (21) have a radius within the range 2 to 5(Alpha)m. The distance network (22) has a thickness of 1 to 2 mm and consists of intersecting strips. The plastic foil (23) has a thickness of about0, 1 mm. The plates (11, 12) comprise a frame (110, 120) with four through holes, of which two holes (for example 111, 114) have connection to a depression (115) in the plate, while two holes (112, 113) have no such connection. The plates in the two pluralities of plates are so turned that holes (122, 123) with connection in the first plurality of plates correspond to holes (112, 113) without connection in the remaining plurality of plates. The frames (130) of the separating pieces include four through holes (131, 132, 133, 134) corresponding to the holes of the plates. Inflow means (101, 103) and, respectively, outflow means (104, 102) are connected to respective holes (111, 123; 114, 122) with connection in the two pluralities of plates.

Description

Arrangement for passing a first liquid close to, but without mixing it with a second liquid, for example an arrangement for sea water desalina- tion.

BACKGROUND OF THE INVENTION This invention relates to an arrangement for permitting a first liquid to flow close to a second liquid, but without being mixed therewith, in order, for example, to recover freshwater by distillation of sea water or to transfer heat from a relatively hot liquid to a relatively cold liquid. The arrangement is of a kind which comprises a first number of plates intended for the first liquid, and a second number of plates intended for the second liquid, which are located between, but separat¬ ed from plates in the first number of plates. All plates are well separated from each other by means of special separating pieces located between each two of said plates. PRIOR ART

It is previously known to recover freshwater from sea water by low- temperature distillation, see e.g. SE-PS 3-7 927, in which an arrange¬ ment is disclosed which comprises a plurality of plane-parallel plates, on every second one of which relatively cold freshwater flows and on every second one of which relatively warm, solar-heated sea water flows.

It is necessary that the plates with sea water and, respectively, fresh¬ water flow thereon are separated from each other, in order to prevent intermixing of the two flows. The said patent specification describes distance members, which consist of grooves turned upside down, and it also describes special means for distributing the liquids to the different plates and corresponding collecting means.

The object of the present invention is to provide devices of the afore¬ mentioned kind but so modified that a higher efficiency is achieved through a simplified and more compact construction. SUMMARY OF THE INVENTION

The invention relates to a special design of the said separating pieces, in such a manner, that each of the pieces comprises an outer porous hydrophobic plastic diaphragm, the voids of which have such a radius that at the hydrostatic pressures prevailing in the arrangement water passage through the plastic diaphragm is prevented, while passage of water vapour is rendered possible, an intermediate distance network of plastic and an outer thin plastic foil, all clamped in a frame, which in its upper portion is provided with inlet apertures for air and in i its lower portion with outlet apertures for water.

The invention also relates to a special design of the two numbers of plates, in such a manner, that they are adapted together with the separating pieces to be assembled to one unit, which is provided with separate inflow and outflow means for the two liquids. The characterizing features of an arrangement according to the inven¬ tion are apparent from the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in greater detail with reference to the accopmanyϊng drawings, in which - Fig. 1 schematically shows the location of plates and separating pieces relative to each other an supply and discharge means,

- Fig. 2 is a sectional lateral view of a separating piece,

- Fig. 3 is a front view of a portion of a distance network comprised in a separating piece, and - Figs. 4, 5, 6 are front views of the frame configuration of a separat¬ ing piece, of a plate in a first number of plates and of a plate in a second number of plates.

The arrangement according to Fig. 1 comprises a plurality of plates prior to their mechanical assembly to one unit. An outer plate 10 includ- es a first supply means 101, a second supply means 103, a first discharge means 104 and a second discharge means 102. A second outer plate 14 ^'■ includes corresponding supply means 141,143 and discharge means 144, 142. Between the said outer plates a first plurality of plates 11, a second plurality of plates 12 and separating pieces 13 are located. The drawing shows only one plate 11 -*ne plate 12 and one separating piece 13, but in reality there are a great number of plates 11, which by means of separating pieces 13 are spaced from an equal number of tightly abutting plates 12.

As appears form Fig. 2, a separating piece 13 comprises a frame 130 about plate-shaped mutually plane-parallel partial pieces, viz. an outer porous hydrophobic (water repel lant) plastic diaphragm 21, an inter¬ mediate distance network 22 of platic and an outer thin plastic foil 23- The frame 130 includes in its upper portion inlet holes 1301 for air and in its lower portion outlet holes 1302 for water. The plastic diaphragm 21 consists of a porous material with a void radius of within the range 2 to 5 y^~ -

The distance network 22 comprises vertical strips 222, see also Fig. 3, and perpendicularly thereto slightly downward directed cross-strips 221. The network has a thickness of about 1 to 2 mm, and the extension of the cross-strips 221 perpendicularly to ther vertical strips 222 is about 0,5 to 1 mm.

The ratio of the distance between the cross-strips 221 and the distance between the vertical strips 222 preferably is chosen to be about 20, for exampel the cross-strip distance = 50 mm, and the vertical strip distance = 2 to 4mm.

The plastic foil 23 consists of polyethylene and has a thickness of about 0,1 mm.

As appears from Fig.4, the frame 130 for a separating piece 13 is provided with four through holes 131,132,133,134. These holes have no connection to the space defined by the frame and intended for the partial pieces 21,22, 23.

Fig. shows a plate 11 comprised in said first plurality of plates. Said plate consists of a frame 110 with four through holes 111,112,113 and 114 in the periphery of the frame. Two of said holes, viz. the holes 111 and 114, have connection to a depres¬ sion (recess) 115 extending over a large part of the plate, while the re¬ maining holes 112,113 have no such connection.

Fig. 6 shows a plate 12 comprised in said second plurality of plates. This plate consists of a frame 120 with four through holes 121,122,123,124 in the periphery of the frame.

The holes 122 and 123 have connection to a depression in the plate, -.ile the holes 121 and 124 have no such connection.

The plates 11 and 12 are identical relative to each other, but so turned in relation one to the other that holes 122,123 with connection to the depression of the plate in plate 12 correspond to holes 112,113 without connection to the depression of the plate in plate 11. As a direct con¬ sequence, the holes 111,114 in the plate 11 correspond to the holes 121 and 124 in the plate 12. The separating pieces 13 prevent direct intermixing of, for example, relatively warm sea water with relatively cold freshwater at the produc¬ tion of freshwater by distillation of the sea water.

The porous hydrophobic plastic diaphragm 21 is located between a plate 11 for the warm sea water and the distance network 22 and has the object to permit the passage of water vapour.

The distance network 22 has the object to provide an air gap between the diaphragm 21 and the plastic foil 23.

The plastic foil 23 has the object to act as condensation surface.

Due to the fact that the plastic diaphragm 21 and the plastic foil 23 include the distance network 22 (i.e. an air gap), a detached condensa¬ tion chamber is formed where the water vapour is condensed out which has no contact with the warm water side nor with the cold water side. This implies in principle that both the warm water side and the cold water side can be charged with sea water. Owing to the design of the separating piece, there is no risk that the plastic diaphragm is deplet¬ ed of air and entirely or partially filled with liquid. The plastic foil 23 shall be so thin that the condensation heat easily can be conducted away by the cold liquid. A uniform water contact against the foil is obtained when the foil is dull finished.

Claims

Cl a i ms

1. An arrangement for permitting a first liquid to flow close to a second liquid, but without being intermixed therewith, for exampel for the recovery of freshwater by distillation of sea water or for the 5 transfer of heat from a relatively warm liquid to a relatively cold liquid, comprising a first plurality of plates intended for the first liquid and a second plurality of plates intended for the second liquid and placed between, but separated from plates in the first plurality of plates, all plates being well separated from each other by special

10 separating pieces located between each two of said plates, c h a r a c ¬ t e r i z e d i n that the separating pieces (13) comprise each a frame about plate-shaped mutually plane-parallel partial pieces, viz. an outer porous and hydrophobic plastic diaphragm (21) with such void radius, that water passage through the plastic diaphragm at the hydro-

15 static pressures prevailing in the arrangement is prevented, while passage of water vapour is rendered possible, an intermediate distance network (22) of plastic and an outer thin plastic foil (23), which frame is provided in its upper portion with inflow holes for air and in its lower portion with outflow holes for water.

202. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that the porous plastic diaphragm (21) has voids with the radius within the range 2 to 5 urn, that the distance network (22) has a thick¬ ness of about 1 to 2 mm and consists of vertical strips and perpendicu¬ larly thereto cross-strips, which are slightly downward directed and

25 extended about 0,5 to 1 mm perpendicularly to the vertical strips, and that the plastic foil (23) has a thickness of about 0,1 mm and consists of polyethylene.

3. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that the plates (11) in the first plurality of plates each comprise

30 a frame (110) with four-tjirough holes (111,112,113,114) in the periphery of the frame, of which holes two ones (111,114) have connection to a ' depression (115) extending over a large part of the plate, while the two remaining holes (112,113) have no such connection, that the plates (12) in the second plurality of plates each comprise a frame (120), four holes

35 (121,122,123,124) and a depression (125) similar to the plates in the first plurality of plates, but so turned in the arrangement, that holes (122,123) with connection in the second plurality of plates correspond to holes (112,113) without connection in the first plurality of plates, and vice versa, and that the frames (130) of the separating pieces (13) are provided with four through holes (131,132,133,134) in the periphery of the frame which correspond to the holes in said two pluralities of plates, and that the two pluralities of plates with intermediate separat¬ ing pieces are mechanically held together to form a liquid-tight unit and have first inflow means (101,141) for the first liquid connected to holes (111) with connection in the first plurality of plates (11), second in¬ flow means (103,143) for the second liquid connected to holes (123) with connection in the second plurality of plates (12), first outflow means (104,144) for the first liquid connected to remaining holes (114) with connection in the first plurality of plates (11) and second outflow means (102,142) for the second liquid connected to remaining holes (122) with connection in the second plurality of plates (12).