Fluid treatment apparatus with semi-permeable membranes, useful as a haemodialyser
AssigneeHospal Industrie
InventorsRobert Benattar, Michel Cronenberger
Life of this patent
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Abstract
The invention relates to a fluid treatment apparatus resulting from the stacking of plates 1 each having, on each of their two main faces, a treatment zone 3 provided with ribs 2, the two membranes being placed between the opposite faces of each adjacent plate 1 of the stack. The two membranes between each adjacent plate are held at a multiplicity of points by the ribs of adjacent plates, at least one rib, and preferably both, at each such point having at least one portion 14 of maximum height H only over a length l which is less than the total length L of that rib or the distance between maximum height portions on that rib. The apparatus is particularly useful in the medical field, especially as a haemodialyser.
Claims8
Hemodialysis apparatus comprising:
- means for providing minimum ultrafiltration rates whilst maintaining dialysis performance characteristics, including:
- (a) a stack of superposed plates, each plate being of elongate form and having a longitudinal axis;
- (b) two opposite major faces on each plate;
- (c) a semi-permeable membrane on each of said two major faces of each plate of the stack, the two membranes thus being located between adjacent plates of the stack;
- (d) means defining a fluid treatment zone on each of said major faces of each plate, each treatment zone having two ends;
- (e) means for feeding fluid to be treated to one end of the treatment zone on each face of each plate and between the two membranes and withdrawing it from between said two membranes at the other end of said treatment zones;
- (f) means for feeding a treating fluid at the location of one end of the treatment zone on each major face of each plate and between said major face and the adjacent membrane, and means for withdrawing the treatment fluid therefrom at the other end of the treatment zone;
- (g) a plurality of membrane supporting ribs upstanding from the major face of each plate, the ribs being disposed in a zig-zag arrangement on each major face of each plate, and intersecting with the opposite ribs on the adjacent major face, the two membranes between two successive plates being in contact at points where the opposite ribs intersect, at least one rib at each such point having at least one portion of maximum height H only over a length l, the ration l/L being between 0.1 and 0.3, L which is between 5 to 15 mm denoting either the length of a rectilinear rib having only one portion of maximum height H in its length, or the distance between two portions with a maximum height H following each other on a rectilinear rib when the ribs of two adjacent major faces clamp the membranes through the intermediacy of more than one portion of maximum height H on a rectilinear length of a rib, the ribs at each point where they intersect being at an angle .alpha. to the longitudinal axis of the plate on one face and being at an angle -.alpha. for the face of the adjacent plate, said angles .alpha. or -.alpha. being between 10.degree. and 45.degree., in absolute value, with said longitudinal axis.
Dependencies are inferred from the claim text.