Membrane Filter Elements
32 Operating Manual Status: 06/2001/01
Squeeze medium quantity
The quantity of squeeze medium per cycle is calculated as follows:
Chamber volume - final cake volume = squeeze medium quantity
Squeezing volume flow
The required volume flow is not exclusively dependent on the squeeze time and the
calculated squeeze volume. The natural dewatering rate of the filter cake is of primary
relevance.
Squeezing pressure rise
The squeeze pressure rise is of major importance for:
• the dewatering
• the squeeze results
• the membrane life and operating safety
The squeezing pressure rise is directly influenced by the dewatering rate.
6.3.1 Possible connections for squeeze media
The squeeze medium can be fed through the individual external or through a collective
internal inflation system into the membrane filter elements. The individual external inflation
system is always advantageous, since leakage and contamination of the squeeze medium
are virtually eliminated.
Individual external inflation system
With the individual external inflation system, the membrane filter elements are supplied with
squeeze medium via flexible pressure-rated hoses from a manifold mounted alongside the
press.
The length of the hoses is such that the filter elements can be moved freely and tension-
free by the plate shifting system. The filter elements are equipped with either screw-type of
flange-type hose connections for this purpose.
Example
If a filter cake is squeezed from 40 mm to 35 mm, the required squeeze medium volume
= 12.5 % x chamber volume.
Information
The conditions required in each case can only be determined empirically.
The maximum permissible squeezing pressure rise for the membrane filter
elements is shown in Graph 13 (page 63) and Graph 15 (page 64).
