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 ( 1 a ) 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 ).

That which is claimed is: 
     
         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 ( 1   a ) 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 ( 1   a ) 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 μm 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 μm 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 μm and 200 μm or between 10 μm and 150 μm.