Enthalpy Exchanger Element And Method For The Production

Abstract

Enthalpy exchanger elements which allow the creation of enthalpy exchangers whereby the efficiency of sensible energy exchange and latent energy exchange can be varied and controlled and especially improved. Also, a method for the production of enthalpy exchanger elements including: a) perforating a flat plate element (1) according to a predetermined perforation pattern (2, 2, . . . ) within the plate outer dimensions, or providing a plate element (1) with an inherent pore structure; b) applying to at least one side (1a) of the plate element (1) a thin polymer film (3) with water vapor transmission characteristics; c) forming the plate element (1) into a desired shape exhibiting a corrugation pattern (4, 4, . . . ), whereby the polymer film (3) is formed into the same corrugation pattern shape as that of the plate element (1).

Claims

1. A method for the production of enthalpy exchanger elements, the method comprising: a) perforating a flat plate element (1) according to a predetermined perforation pattern (2, 2, . . . ) within the plate outer dimensions, or providing a plate element (1) with an inherent pore structure; b) applying to at least one side (1a) of the plate element (1) a thin polymer film (3) with water vapor transmission characteristics (water vapor transfer ratio, WVTR), thereby completely covering the plate element as well as the holes or perforations, or the inherent pore structure; c) forming the plate element (1) into a desired shape exhibiting a corrugation pattern (4, 4, . . . ), whereby the polymer film (3) is formed into the same corrugation pattern shape as that of the plate element (1); and whereby the plate element is a plastic plate and whereby a total open area for water vapor transfer on no less than 50% of the available plate exchange surface is provided.

2. The method according to claim 1, wherein the plate is perforated using at least one of needles, pins, die and punch, or a laser.

3. The method according to claim 1, wherein steps b) and c) are performed simultaneously.

4. The method according to claim 3, wherein the polymer film is bonded, preferably heat bonded and/or glued, to the plate element during the forming step of the plate element.

5. The method according to claim 1, wherein said polymer film is made of a sulfonated copolymer, preferably a block copolymer.

6. The method according to claim 1 wherein the spatial frequency of the corrugations of the corrugation pattern and the density of the perforations in the perforation pattern is varied in a border area of the corrugation pattern and a border area of the perforation pattern in order to improve frost resistance.

7. An enthalpy exchanger element comprising: a plate element (1) with a shape exhibiting a predetermined perforation pattern (2, 2, . . . ); and a predetermined corrugation pattern (4, 4, . . . ); wherein at least one side (1a) of the plate element (1) is covered by a thin polymer film (3) with water vapor transmission characteristics (water vapor transfer ratio, WVTR).

8. The enthalpy exchanger element of claim 7, wherein the thin polymer film is bonded, preferably heat bonded and/or glued, to the plate element.

9. The enthalpy exchanger element according to claim 7, wherein the perforated area of the plate element includes corrugated or embossed surface areas.

10. The enthalpy exchanger element according to claim 8, wherein the width of corrugations (4) in the border areas of the plate element (1) is larger than the width of corrugations (4) in the middle area of the plate element (1) and/or the perforation density (i.e. number of perforations per unit area) in a border area of the plate element is larger than in the middle area of the plate element.

11. The enthalpy exchanger element according to claim 7, wherein the corrugations are oriented to guide a fluid flow.

12. The enthalpy exchanger element according to claim 7, wherein the perforations are openings of diverse shapes and with a surface area equivalent to hole diameters ranging from 30 m to 1.2 mm, preferably providing a total open area of no less than 50% of the available plate exchange surface.

13. The enthalpy exchanger element having the plate like heat exchanger elements according to claim 7, wherein at least three plates like enthalpy exchanger elements fixed to each other in parallel orientation to form two fluid paths allowing fluids to flow there through.

14. The enthalpy exchanger element according to claim 13, wherein the enthalpy exchanger elements are fixed to each other by means of welding such as laser welding or ultrasonic welding, or by means of gluing.

15. The enthalpy exchanger element according to claim 7, wherein the border areas of the plate element are not perforated, preferably in a range of 5 to 20 mm, more preferably in a range of 10 to 20 mm, from the outer dimensions of the plate element.

16. The enthalpy exchanger element according to claim 7, wherein the perforations may be openings of diverse shapes and with a surface area equivalent to hole diameters ranging from 30 m to 1.2 mm, preferably providing a total open area of no less than 50% of the available plate exchange surface area.

17. The enthalpy exchanger element according to claim 7, wherein the plate element is (i) a porous polymer plate, (ii) a woven or non-woven fabric made from polymer fibers, inorganic fibers or metal fibers, (iii) a composite made using a woven or non-woven fabric made from polymer fibers, inorganic fibers or metal fibers, (iv) a composite which includes a porous polymeric material as a matrix, or (iv) combinations thereof.

18. The enthalpy exchanger element according to claim 7, wherein said thin polymer film is a multilayer film further comprising a sequence of polymer layers of different polymer types.

19. The enthalpy exchanger element according to claim 18, wherein the polymer type of each polymer layer is selected from the group consisting of polyether ester, polyether amide and polyether urethane.

20. The enthalpy exchanger element according to claim 18, wherein the total thickness of the thin polymer multilayer film is between 5 m and 200 m or between 10 m and 150 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Further features, advantages and aspects of the invention become obvious from the following description of the drawings. The drawings show

[0052] FIG. 1 a flow chart illustrating a sequence of steps of the production method according to the invention; and

[0053] FIG. 2 a sequence of states of the production of an enthalpy exchanger element in cross sectional view during the production method according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] In FIG. 1, a sequence of steps of the production method according to the invention are shown. Each step shown in FIG. 1 corresponds to a resulting state schematically shown in FIG. 2. It should be noted that the illustrated geometric parameters such a thicknesses, hole diameters, curvatures etc. in FIG. 2 are for exemplary purposes, only. Therefore, they do not necessarily represent the proper or preferred ratios of such parameters.

[0055] In providing step S1, a flat yet unformed plastic plate element 1 with defined outer dimensions is provided. In perforating step S2, a portion of the flat plastic plate element 1 is transferred to a perforation device (not shown) where the flat plastic plate element 1 is perforated by a needle-roller or a punching die (not shown) depending on the desired size of the holes. In the present case, the entire plate element 1 is perforated with a symmetric hole pattern, except for the border areas (not shown) to allow welding of the plate elements 1 in order to form the plate exchanger (not shown). The perforation pattern is made up of a plurality of holes 2 extending across the entire plate thickness from a first surface 1a to a second surface 1b of the plate element 1.

[0056] Subsequently to the perforating step, in covering step S3, one side, i.e. surface 1a, of the now perforated plate element 1 is completely covered by a thin polymer film 3. The polymer film is made of a proprietary sulfonated block copolymer or any type of such sulfonated block copolymers.

[0057] Subsequently to the covering step, in forming step S4, the now perforated and covered flat plate element 1 is transferred to a forming device, which is embodied by a vacuum forming device, where the flat plate element 1 and the thin polymer film 3 are formed into a desired shape. In this forming step S4, the border areas, fluid inlets and outlets and corrugations 4 are formed into the plate element 1. The corrugation pattern is made up of a plurality of corrugations 4 extending across the plate area.

[0058] In the present embodiment of the invention, the border areas are being formed in non-perforated areas, while the corrugations are being formed in perforated areas of the plate element 1.

[0059] Thereby, during the forming step S4 which is a co-forming step of the flat plate element 1 and the thin polymer film 3, the thin polymer film 3 is formed into the exact same shape as the plate element 1 and is permanently bonded thereto, due to the heat, which is applied by the vacuum forming device.

[0060] These thin-polymer-film-covered and co-formed plates 1 constitute the enthalpy exchanger plates according to the invention. They will be stacked to build an enthalpy exchanger (also referred to as a total energy exchanger) core e.g. for ventilation systems to exchange heat from outgoing to incoming air (or vice versa for free cooling in summer) as well as humidity from outgoing to incoming air in winter (or vice versa for moisture reduction in summer or all year round in hot and humid climatic zones).

[0061] The cross sectional shape of the corrugations 4 may be rectangular, square or triangular. It may also be trapezoidal such half hexagonal.

[0062] The drawing and the description do in no way restrict the invention and are meant for illustrating the invention by an example, only.

REFERENCE NUMERALS

[0063] 1 flat plate element [0064] 1a first surface [0065] 1b second surface [0066] 2 hole [0067] 3 thin polymer film [0068] 4 corrugation [0069] S1 providing step [0070] S2 perforating step [0071] S3 covering step [0072] S4 forming step (co-forming)