Dialyzers parallel-plate dialyzer

S.D. Kolev, W.E. van der Linden, Influence of the main parameters on a parallel plate dialyzer under laminar flow conditions, Anal. Chim. Acta 257 (1992) 317. 

In an attempt to decrease boundiy-layer resistance, while at the same time maintaining laminar flow, Abel et al.19 have designed a parallel-plate dialyzer that uses vortax mixing to disrupt the bouadaiy layers. Through this mechanism, they were able to reduce overall mass transfer resistance by a factor of 2-3 compared with conventional parallel-plate dialyzers containing the same membmae. 

Parallel-plate hemodialyzers using flat membranes, with several compartments in parallel, separated by plastic plates, are now only available from Hospal Co (Crystal and Hemospal models). Blood circulates between two membranes and the dialysate between the other side of membrane and the plastic plate. These parallel-plate dialyzers have a smaller blood-pressure drop than hollow-fiber ones and require less anticoagulants as flat channels are less exposed to thrombus formation than fibers, but they are heavier and bulkier and thus less popular. A recent survey of the state-of-the-art in hemodialyzers is given in [13]. 

Based on the membrane design and configuration, there are three types of dialyzers available. The design of the membrane is crucial to determine the efficiency of the dialysis (how much and how sufficiently the blood can be filtered). The basic membrane designs for dialyzers are hollow fiber, parallel plate and coil dialyzers, and each one has its own disadvantages and advantages over the other, but all of them ultimately have the same function. 

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