HEAT AND MATERIAL EXCHANGER

Abstract

This exchanger (100) includes: substantially parallel and vertical membranes (30), permeable to vapor and impermeable to a liquid, these membranes delimiting zones, each of said zones belonging alternately to a first type of zone and to a second type of zone; the zones of said first type including in the upper portion a spray nozzle (20) configured to vaporize a liquid along a plane (R) substantially parallel to the membranes, and in the lower portion a first collector (50), independent and separated from the zones of the second type, a first pipe (10) supplying the spray nozzles (20) of the zones (Z20) of said first type with a liquid.

Claims

1. An exchanger including: substantially parallel and vertical membranes, permeable to vapor and impermeable to a liquid, said membranes delimiting zones, each of said zones belonging alternately to a first type of zone and to a second type of zone; the zones of said first type including in the upper portion a spray nozzle configured to spray a liquid along a plane substantially parallel to said membranes, and in the lower portion a first collector, independent and separated from the zones of the second type, a first pipe supplying the spray nozzles of the zones of the first type with a liquid.

2. The exchanger according to claim 1, wherein it includes: a passage allowing the circulation of a gas in the zones of the second type.

3. A method for using an exchanger according to claim 2, including: a step of circulating a relatively hot and humid gas in the zones of the second type; a step of circulating a relatively cold and salt-rich liquid in said first pipe, said liquid being sprayed by said spray nozzles in the zones of said first type; and a step of collecting a warmed and diluted liquid in said first collector.

4. The method for using an exchanger according to claim 2, including: a step of circulating a relatively cold gas in the zones of the second type; a step of circulating a relatively hot and salt-poor liquid in said first pipe, said liquid being sprayed by said spray nozzles in the zones of said first type; and a step of collecting a cooled and concentrated liquid in said first collector.

5. The exchanger according to claim 1, wherein: the zones of said second type including in the upper portion a spray nozzle configured to vaporize a liquid along a plane substantially parallel to said membranes, and in the lower portion a second collector, independent and separated from the zones of said first type. said exchanger also including: a second pipe supplying the spray nozzles of the zones of said second type with a liquid.

6. The method for using an exchanger according to claim 5, including: a step of circulating a relatively cold and salt-poor liquid in said first pipe, said liquid being sprayed by said spray nozzles in the zones of said first type; a step for circulating a relative hot and salt-rich liquid in said second pipe, said liquid being sprayed by said spray nozzles in the zones of said second type; a step of collecting a warmed and diluted liquid in the second collector in the lower portion of the zones of the first type; and a step of collecting a cooled and concentrated liquid in the second collector in the lower portion of the zones of the second type.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Other features and advantages of the present invention will appear in the following description of a given embodiment, given by way of a non-limiting example, with reference to the appended drawings, in which:

[0040] FIG. 1 shows an exchanger conforming to a first embodiment of the invention;

[0041] FIG. 2 shows an exchanger conforming to a second embodiment of the invention; and

[0042] FIGS. 3 and 4 show an exchanger conforming to a third embodiment of the invention.

FIRST EMBODIMENT

[0043] FIG. 1 shows an exchanger 100 conforming to a first embodiment of the invention. It can be used to refresh and dehumidify hot and humid air (for example 25° C. and 60% RH) circulating in the zones Z30 delimited by membranes 30 permeable to water vapor. A fan 40 can be used for blowing the hot air.

[0044] In the embodiment described here, a zone Z20 with a spray nozzle 20 over it is located on either side of each air circulation zone Z30. These spray nozzles 20 are supplied by a pipe 10 in which a cold (typically 15° C.) and salt-rich liquid circulates. The spray nozzles 20 spray the liquid substantially into a flat sheet R parallel to the membranes 30.

[0045] In this embodiment of the invention, like in those described hereafter, the liquid supply pressure upstream of the nozzles can be on the order of 2 bars.

[0046] When the salt-rich liquid is sprayed by the spray nozzles 20 in the zones Z20, the air comprised in these zones Z20 surrenders its humidity which is absorbed by the salt. It becomes colder and drier than the air in the zones Z30.

[0047] The air in the zones Z30 cools and its humidity migrates toward the zones Z20 through the membranes 30, as shown by the horizontal arrows. The liquid in the zones Z20 is diluted; it is recovered in a collector 50 arranged so that the liquid collected is not in contact with the zones Z30.

[0048] In this embodiment:

[0049] the more the liquid sprayed by the spray nozzles 20 is concentrated with salt, the more the dehumidification of the hot and humid air in the zones Z30 is favored; and

[0050] the more the liquid sprayed by the spray nozzles 20 is cold, the more the cooling of the air circulating in the zones Z30 is favored.

SECOND EMBODIMENT

[0051] FIG. 2 shows an exchanger 200 conforming to a second embodiment of the invention. It can be used to cool and concentrate a hot and salt-poor, or even salt-free liquid.

[0052] In the embodiment described here, this liquid (at 35° C. for example) is sprayed by the spray nozzles 21 in zones Z21 delimited by membranes 30 permeable to water vapor, the spray nozzles being supplied by a pipe 11. The spray nozzles 21 spray the liquid substantially in a flat sheet R parallel to the membranes 30.

[0053] As in the first embodiment, the zones Z21 are separated by zones Z30 in which air circulates. But in this embodiment, the air in these zones Z30 is colder than the liquid sprayed in the zones Z21. The air in the zones Z30 is for example at ambient temperatures, for example at 24° C.

[0054] In the zones Z21, the air, in contact with the hot sprayed liquid, is warmed and charged with humidity. The liquid cools and is concentrated. It is collected in a collector 51 arranged so that the liquid collected is not in contact with the zones Z30.

[0055] The water vapor migrates from the zones Z21 to the zones Z30 through the membranes 30 as shown by the horizontal arrows. In the zones Z30, the air is warmed and is charged with humidity.

[0056] This second embodiment of the invention advantageously allows cooling the liquid below the temperature of the air circulating in the zones Z30, thanks to the phenomenon of evaporation, until it attains the wet-bulb temperature.

THIRD EMBODIMENT

[0057] FIGS. 3 and 4 show a third embodiment of the invention. It can be used to desalinate a liquid.

[0058] In this embodiment, the exchanger 300 includes:

[0059] a pipe 10 supplying the spray nozzles 20 with a cold salt-poor, or even salt-free liquid, this liquid being sprayed by the spray nozzles 20 in the zones Z20; and

[0060] a pipe 11 supplying the spray nozzles 21 with a hot, concentrated salt liquid, this liquid being sprayed by the spray nozzles 21 in the zones Z21.

[0061] The zones Z20 and Z21 are alternated and separated by membranes 30 permeable to water vapor. In each of the zones, the spray nozzles 20, 21 spray the liquid in a flat sheet R substantially parallel to the membranes.

[0062] In the zones Z21, the air in contact with the hot liquid is warmed and is charged with humidity. The water vapor migrates toward the zones Z20 through the membranes 30.

[0063] In the zones Z20, the air is warmed and is charged with water vapor due to the migration of water vapor coming from the zones Z21 as shown by the horizontal arrows.

[0064] In the zones Z20, the air surrenders its heat to of the flow of cold, salt-poor liquid increasing the quantity of water. The hot and diluted liquid is collected in a collector 50 arranged so that this liquid is not in contact with the zones Z21.

[0065] In the zones Z21, the quantity of water is reduced due to the migration, and the salt-rich liquid is concentrated. The cold and concentrated liquid is exhausted by U-shaped pipes leading through openings 61 into a collector 51 arranged so that this liquid is not in contact with the zones Z20.

[0066] This embodiment allows concentrating the salt-rich liquid introduced into the pipe 11: it can be used for desalination operations.

[0067] In this third embodiment of the invention, the exchanger 300 has a structure 7 to which the membranes 30 are attached. The collectors 50 and 51 have shoulders in which these membranes 30 are inserted, thus avoiding any contact between the different liquids.

[0068] An arrangement of this type can also be used in the exchangers 100 and 200 described previously with reference to FIGS. 1 and 2 to avoid contact between the liquid in the collectors 50, 51 and the air circulating in the zones Z30.

OTHER USE EMBODIMENT OF THE INVENTION

[0069] As previously mentioned, in the embodiment of FIG. 1, the solution recovered in the collector 50 is diluted by the water vapor which has migrated from the zones Z30 through the membrane 30. It is necessary, to be able to re-use it at the input to the pipe 10, to remove the water added to it.

[0070] To carry out this operation, it is possible to head the diluted solution recovered in the collector 50 and to inject it into the pipe 11 of the exchanger of FIG. 2 in order to reduced its temperature and to concentrate it.