Patent US3878086A successfully refreshed from Google Patents.
US3878086A
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Electrodialysis stack and spacer for use therein
Assignee: LEA MANUFACTURING COMPANY A CT CORP
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Filing: 1972-05-01
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Granted: 1975-04-15
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Expires: 1992-05-01
Abstract
Abstract An improved electrodialysis stack and method of constructing the same wherein a multi-ply membrane spacer is used, the spacer consisting of a relatively thick and relatively flexbiel interior ply and two relatively thin exterior plies formed of a more rigid material than is the interior ply. These exterior plies are held together by a water-resistant pressure-sensitive adhesive. The resultant spacer may be adhesively bonded to cationic and anionic membranes on each side thereof, and thereby form a part of an essentially solid laminar dialysis stack which is free from cross-leaking and seepage problems.
Inventors
- 👤 David B Haswell
- 👤 John L Eisenmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:37
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/42; B01D61/44; B01D61/46; B01D61/50
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
84 words
A flow-directing spacer for use between the cationic and anionic membranes of electrodialysis apparatus comprising a relatively thick inner ply of a relatively low modulus polymer sandwiched between two outer and relatively thin plies of relatively high modulus polymer, wherein the bonds between the outer and inner plies are formed of a pressure sensitive adhesive, and wherein a turbulence promoting means is placed within a flow path defined by an aperture in said spacer, the aperture being the depth of the three said plies
Claim 2
Dependent Claim
84 words
A flow-directing spacer for use between the cationic and anionic membranes of electrodialysis apparatus comprising a relatively thick inner ply of a relatively low modulus polymer sandwiched between two outer and relatively thin plies of relatively high modulus polymer, wherein the bonds between the outer and inner plies are formed of a pressure sensitive adhesive, and wherein a turbulence promoting means is placed within a flow path defined by an aperture in said spacer, the aperture being the depth of the three said plies
Claim 3
Dependent Claim
28 words
A spacer as defined in claim 1 wherein the total thickness of the inner ply is equal or greater than the total thickness of the two outer plies.
Claim 4
Dependent Claim
24 words
A spacer as defined in claim 1 wherein said outer plies formed of polyester terephthalate and said inner ply if formed of a polyolefin.
Claim 5
Dependent Claim
44 words
An electrodialysis apparatus formed of a laminated block article wherein the ion exchange membranes and spacers as defined in claim 1 are adhered together with an adhesive and comprising within said block separate conduits for the flow of concentrated and diluent through said block.
Claim 6
Dependent Claim
20 words
A stack as defined in claim 4 wherein a major portion of the volume of the said block is hollow.
Claim 7
Dependent Claim
52 words
A process for making an electrodialysis apparatus comprising the step whereby the anionic and cationic membrane are bonded to a spacer on each side thereof and over at least 20% of the surface of the membrane by means of a substantially volatile-free pressure sensitive adhesive thereby forming an integral block shaped laminate.
Claim 8
Dependent Claim
52 words
A process for making an electrodialysis apparatus comprising the step whereby the anionic and cationic membrane are bonded to a spacer on each side thereof and over at least 20% of the surface of the membrane by means of a substantially volatile-free pressure sensitive adhesive thereby forming an integral block shaped laminate.
Claim 9
Dependent Claim
19 words
A process as defined in claim 6 wherein said adhesive bond is formed with a double-coated adhesive base sheet.
Claim 10
Dependent Claim
38 words
A process as defined in claim 7 wherein said adhesive bond is formed by transferring said adhesive from a release sheet onto each side of a spacer and then pressing a membrane against each side of said spacer.
Claim 11
Dependent Claim
80 words
A multi-ply membrane flow-directing spacer of claim 1 for use between the ionic membranes of an electrodialysis stack including (1) an inner ply defining a primary flow path, manifold-defining inlet and outlet ports, and channels connecting said flow path to said inlet and outlet ports and (2) two exterior plies defining the same primary flow path configuration and manifold defining inlet and outlet ports but being free of any channel connecting said flow path and said inlet and outlet ports.
Claim 12
Dependent Claim
17 words
A spacer as defined in claim 9 comprising a flow-distributing means substantially throughout the aforesaid flow path.
Claim 13
Dependent Claim
16 words
A spacer as defined in claim 10 wherein said flow distributing means extends into said channels.
Claim 14
Dependent Claim
26 words
A spacer as defined in claim 9 wherein said inner ply is equal or greater in thickness than the total thickness of the two outer plies.
Claim 15
Dependent Claim
20 words
A spacer as defined in claim 10 wherein the plies are bonded to one another by a pressure-sensitive adhesive means.
Claim 16
Dependent Claim
71 words
Electrodialysis apparatus as defined in claim 4 where said spacers include (1) an inner ply defining a primary flow path, manifold-defining inlet and outlet ports and channels connecting said flow path to said inlet and outlet ports and (2) two exterior plies defining the same primary flow path configuration and manifold-defining inlet and outlet ports but being free of any channel connecting said flow path and said inlet and outlet ports.
Claim 17
Dependent Claim
28 words
Electrodialysis apparatus as defined in claim 14 wherein at least 20% of the surface area of all said membranes are bonded to the opposing surfaces of said spacers.
Claim 18
Dependent Claim
19 words
Electrodialysis apparatus as defined in claim 14 wherein said membranes have a flexural rigidity of less than 10,000 mg-cm.
Claim 19
Dependent Claim
18 words
Apparatus as defined in claim 16 wherein said membranes have a flexural rigidity of less than 4,000 mg-cm.
Claim 20
Dependent Claim
17 words
Electrodialysis apparatus as defined in claim 15 comprising a flow-distributing means substantially throughout the aforesaid flow path.
Claim 21
Dependent Claim
17 words
Electrodialysis apparatus as defined in claim 17 comprising a flow-distributing means substantially throughout the aforesaid flow path.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |