Fluid separation cells and spacers for use in these

Claim 2

A spacer assembly, for separating membranes of a fluid chamber in a fluid separation cell, said spacer assembly comprising a pair of spacer sheets (1) disposed in overlying coextensive relationship, and in which each spacer sheet (1) has sides surrounding an open centre (2) defining the sarea of the fluid chamber, conduit passages formed by holes (8, 9) in opposite sides of each spacer sheet (1), respectively, for supply and withdrawal of fluid to an associated cell and a plurality of slots (13, 14) arranged substantially uniformly along each of said opposite sides, each slot (13, 14) extending part way only between one of the conduit passages formed by holes (8, 9) and the open centre (2) and each slot having an open slot mouth (30) and a closed slot end distal from said open slot mouth, wherein the slot mouth (30) opens into either the open centre (2) or the respective conduit passage(s) formed by hole(s) (8), said slots (13, 14) being formed in said spacer sheet sides such that facing sides of adjacent slots define teeth (15, 16) that merge at said closed slot ends into a continuous web (20, 21), and in which the opposite sides of each spacer sheet (1) are in overlying relationship with each other so that the slots (14) in one sheet (1) which have their mouths (30) opening into the open centre (2) cooperate with the slots (13) in the other sheet having their mouths (30) opening into the respective conduit passage(s) formed by hole(s) (8) to provide a continuous fluid passage between the conduit passages formed by holes (8, 9) and the open centre (2), in which: the conduit passages formed by holes (8, 9) comprise a supply conduit passage and a withdrawal conduit passage extending along said opposite sides of the spacer sheet (1) and across substantially an entire width of the open centre (2), the slots (13, 14) are distributed substantially uniformly across a width of each conduit passage, a ratio of a width of the mouth (30) of each slot to a thickness of each spacer sheet (1) being in a range of 0.2:1 to 5:1, and at least some of the slots (13, 14) have a widened closed slot end, the width of said widened closed slot end, transverse to the longitudinal axis of said slot, being greater than the corresponding width of said slot mouth and in which substantially all of the slots (13, 14) which do not have said widened closed slot end in one sheet cooperate with a slot (13, 14) which does have said widened closed slot end in the other sheet such that the cooperating slots (13, 14) which do not have said widened closed slot end overlap with said widened closed slot ends of the slots (13, 14) that do have said widened closed slot ends.

Claim 3

A spacer assembly according to claim 1 in which substantially all the slots (13, 14) have widened closed slot ends.

Claim 4

A spacer assembly according to claim 1 or claim 2, wherein the closed slot ends of said slots having widened closed slot ends are widened on both sides of the respective mouths.

Claim 5

A spacer assembly according to claim 3, in which a ratio of a width of the closed slot ends of the slots (13, 14) which have said widened closed slot end to the width of the mouth (30) of the slots (13, 14) which have said widened closed slot end is in a range of from 1.2:1 to 5.0:1.

Claim 6

A spacer assembly according to claim 4, in which the ratio of the width of the closed slot ends of the slots (13, 14) which have said widened closed slot end to the width of the mouth (30) of the slots (13, 14) which have said widened closed slot end is in the range of from 1.5:1 to 3.0:1.

Claim 7

A spacer assembly according to claim 3, wherein the slots (13, 14) which have a widened closed slot end are triangular, keyhole, or T-shaped.

Claim 8

A spacer assembly according to claim 1 in which a width of the closed slot ends of the slots (13, 14) that have widened closed slots ends is greater than a width of the teeth (15, 16) between the sides of adjacent slots.

Claim 9

A spacer assembly according to claim 1 in which the width of each slot mouth (30) is in the range 0.5 to 3 mm and each spacer sheet (1) has a thickness in the range 0.5 to 3 mm.

Claim 10

A spacer assembly according to claim 1 in which the ratio of the width of the mouth (30) of each slot (13), (14) to the thickness of each spacer sheet (1) is in the range of 0.3:1 to 2:1.

Claim 11

A spacer assembly according to claim 1 in which each spacer sheet (1) has the shape of a regular polygon having an even number of sides and in which the sides not having conduit passages (formed by holes (8, 9) are provided with side passages formed by holes (10, 11) of substantially the same dimensions and positions in their respective sides as the conduit passages formed by holes (8, 9).

Claim 12

A spacer assembly according to claim 10, in which each spacer sheet (1) is square.

Claim 13

A spacer assembly according to claim 1 which is formed from a thermoplastics sheet material.

Claim 14

A spacer assembly according to claim 12, wherein said thermoplastic sheet material is a polyolefin.

Claim 15

A spacer assembly according to claim 12, wherein said thermoplastic sheet material is a polymer of propylene.

Claim 16

A spacer assembly according to claim 1 in which the conduit passages formed by holes (8, 9) in each sheet (1) are each selected from two types of conduit passages, said types consisting of type 1 conduit passages formed by holes (8) characterized in that the slots (13) that are distributed along the type 1 conduit passages all have their mouths (30) opening into the type 1 conduit passage(s) and type 2 conduit passages formed by hole(s) (9) characterized in that the slots (14) that are distributed along the type 2 conduit passage(s) all have their mouths (30) opening into the open centre (2).

Claim 17

A spacer assembly according to claim 15 in which each spacer sheet (1) has a type 1 conduit passage and a type 2 conduit passage and a type 1 conduit passage in one sheet co-operates with a type 2 conduit passage in the other sheet.

Claim 18

A spacer assembly according to claim 15, wherein one of the conduit passages formed by holes (8, 9) in each spacer sheet (1) is a type 1 conduit passage and the other conduit passage is a type 2 conduit passage.

Claim 19

A spacer assembly according to claim 1 in which each spacer sheet (1) is substantially identical but is turned through 180° with respect to the other.

Claim 20

A fluid separation cell, comprising a stack of shallow chambers each of which is defined on its opposing faces by a membrane (17) and around its sides by a spacer assembly, in which the spacer assembly comprises a pair of spacer sheets (1) disposed in overlying coextensive relationship, and in which each spacer sheet (1) has sides surrounding an open centre (2) defining the area of the fluid chamber, conduit passages formed by holes (8, 9) in opposite sides of each spacer sheet (1), respectively, for supply and withdrawal of fluid to an associated cell and a plurality of slots (13, 14) arranged substantially uniformly along each of said opposite sides, each slot (13, 14) extending part way only between one of the conduit passages formed by holes (8, 9) and the open centre (2) and each slot having an open slot mouth (30) and a closed slot end distal from said open slot mouth, wherein the slot mouth (30) opens into either the open centre (2) or the respective conduit passage(s) formed by hole(s) (8), said slots (13, 14) being formed in said spacer sheet sides such that facing sides of adjacent slots define teeth (15, 16) that merge at said closed slot ends into a continuous web (20, 21), and in which the opposite sides of said spacer sheet (1) are in overlying relationship with each other so that the slots (14) in one sheet (1) which have their mouths (30) opening into the open centre (2) cooperate with the slots (13) in the other sheet having their mouths (30) opening into the respective conduit passage(s) formed by hole(s) (8) to provide a continuous fluid passage between the conduit passages formed by holes (8, 9) and the open centre (2), in which: the conduit passages formed by holes (8, 9) comprise a supply conduit passage and a withdrawal conduit passage extending along said opposite sides of the spacer sheet (1) and across substantially an entire width of the open centre (2), the slots (13, 14) are distributed substantially uniformly across a width of each conduit passage, a ratio of a width of the mouth (30) of each slot to a thickness of each spacer sheet (1) being in a range of 0.2:1 to 5:1, and at least some of the slots (13, 14) have a widened closed slot end, the width of said widened closed slot end, transverse to the longitudinal axis of said slot, being greater than the corresponding width of said slot mouth (30), and in which substantially all of the slots (13, 14) which do not have said widened closed slot end in one sheet cooperate with a slot (13, 14) which does have said widened closed slot end in the other sheet such that the cooperating slots (13, 14) which do not have said widened closed slot end overlap with said widened closed slot ends of the slots (13, 14) that do have said widened closed slot ends.

Claim 21

A fluid separation cell, comprising a stack of shallow chambers each of which is defined on its opposing faces by a membrane (17) and around its sides by a spacer assembly, in which the spacer assembly comprises a pair of spacer sheets (1) disposed in overlying coextensive relationship, and in which each spacer sheet (1) has sides surrounding an open centre (2) defining the area of the fluid chamber, conduit passages formed by holes (8, 9) in opposite sides of each spacer sheet (1), respectively, for supply and withdrawal of fluid to an associated cell and a plurality of slots (13, 14) arranged substantially uniformly along each of said opposite sides, each slot (13, 14) extending part way only between one of the conduit passages formed by holes (8, 9) and the open centre (2) and each slot having an open slot mouth (30) and a closed slot end distal from said open slot mouth, wherein the slot mouth (30) opens into either the open centre (2) or the respective conduit passage(s) formed by hole(s) (8), said slots (13, 14) being formed in said spacer sheet sides such that facing sides of adjacent slots define teeth (15, 16) that merge at said closed slot ends into a continuous web (20, 21), and in which the opposite sides of said spacer sheet (1) are in overlying relationship with each other so that the slots (14) in one sheet (1) which have their mouths (30) opening into the open centre (2) cooperate with the slots (13) in the other sheet having their mouths (30) opening into the respective conduit passage(s) formed by hole(s) (8) to provide a continuous fluid passage between the conduit passages formed by holes (8, 9) and the open centre (2), in which: the conduit passages formed by holes (8, 9) comprise a supply conduit passage and a withdrawal conduit passage extending along said opposite sides of the spacer sheet (1) and across substantially an entire width of the open centre (2), the slots (13, 14) are distributed substantially uniformly across a width of each conduit passage, a ratio of a width of the mouth (30) of each slot to a thickness of each spacer sheet (1) being in a range of 0.2:1 to 5:1, and at least some of the slots (13, 14) have a widened closed slot end, the width of said widened closed slot end, transverse to the longitudinal axis of said slot, being greater than the corresponding width of said slot mouth (30), and in which substantially all of the slots (13, 14) which do not have said widened closed slot end in one sheet cooperate with a slot (13, 14) which does have said widened closed slot end in the other sheet such that the cooperating slots (13, 14) which do not have said widened closed slot end overlap with said widened closed slot ends of the slots (13, 14) that do have said widened closed slot ends.

Claim 22

A fluid separation cell according to claim 19 in which the spacer assemblies are square and are all substantially identical and the spacer assemblies in adjacent cell pairs are oriented at about 90° relative to each other and in which there are two fluid streams passing through the cell.

Claim 23

A fluid separation cell according to claim 19, which is a dialysis or electrodialysis cell.

Claim 24

A spacer sheet suitable for use in a spacer assembly having sides surrounding an open centre (2) defining the area of the fluid chamber, conduit passages formed by holes (8, 9) in opposite sides of each spacer sheet (1), respectively, for supply and withdrawal of fluid to an associated cell and a plurality of slots (13, 14) arranged substantially uniformly along each of said opposite sides, each slot (13, 14) extending part way only between one of the conduit passages formed by holes (8, 9) and the open centre (2) and each slot having an open slot mouth (30) and a closed slot end distal from said open slot mouth, wherein the slot mouth (30) opens into either the open centre (2) or the respective conduit passage(s) formed by hole(s) (8), said slots (13, 14) being formed in said spacer sheet sides such that facing sides of adjacent slots define teeth (15, 16) that merge at said closed slot ends into a continuous web (20, 21), in which: the conduit passages formed by holes (8, 9) comprise a supply conduit passage and a withdrawal conduit passage extending along said opposite sides of the spacer sheet (1) and across substantially an entire width of the open centre (2), the slots (13, 14) are distributed substantially uniformly across a width of each conduit passage, a ratio of a width of the mouth (30) of each slot to a thickness of the spacer sheet (1) being in a range of 0.2:1 to 5:1, and at least some of the slots (13, 14) have a widened closed slot end, the width of said widened closed slot end, transverse to the longitudinal axis of said slot, being greater than the corresponding width of said slot mouth (30).

Claim 25

A spacer sheet suitable for use in a spacer assembly having sides surrounding an open centre (2) defining the area of the fluid chamber, conduit passages formed by holes (8, 9) in opposite sides of each spacer sheet (1), respectively, for supply and withdrawal of fluid to an associated cell and a plurality of slots (13, 14) arranged substantially uniformly along each of said opposite sides, each slot (13, 14) extending part way only between one of the conduit passages formed by holes (8, 9) and the open centre (2) and each slot having an open slot mouth (30) and a closed slot end distal from said open slot mouth, wherein the slot mouth (30) opens into either the open centre (2) or the respective conduit passage(s) formed by hole(s) (8), said slots (13, 14) being formed in said spacer sheet sides such that facing sides of adjacent slots define teeth (15, 16) that merge at said closed slot ends into a continuous web (20, 21), in which: the conduit passages formed by holes (8, 9) comprise a supply conduit passage and a withdrawal conduit passage extending along said opposite sides of the spacer sheet (1) and across substantially an entire width of the open centre (2), the slots (13, 14) are distributed substantially uniformly across a width of each conduit passage, a ratio of a width of the mouth (30) of each slot to a thickness of the spacer sheet (1) being in a range of 0.2:1 to 5:1, and at least some of the slots (13, 14) have a widened closed slot end, the width of said widened closed slot end, transverse to the longitudinal axis of said slot, being greater than the corresponding width of said slot mouth (30).

Claim 26

A spacer sheet according to claim 22, in which all of the slots (13, 14) are slots which have said widened closed slot ends.