Membrane Filter Elements
Status: 06/2001/01 Operating Manual 17
6 Operating the Membrane Filter Elements
6.1 Closing the filter press
The closing mechanism of the filter press seals the chambers against the operating
pressure resulting from filtration or squeezing. The closing mechanism yields the surface
pressure required for sealing at the sealing edge.
While holding the filter chambers closed, the closing mechanism compensates for:
• changes in length caused by compressing the filter cloths and by the elasticity of the
filter elements
• changes in length resulting from thermal expansion
The stroke of the closing mechanism must be adjusted. The required stroke results from
the following parameters:
• the required opening distance of the chambers for cake release
• the elasticity of the filter pack including the filter cloths
Warning
To prevent the filter elements from being permanently deformed, overstressing as the
result of excessive closing force is not permitted.
Information
• The closing force must be transferred to the filter elements during operation. Usually,
hydraulic cylinders are used to close the filter press.
• Therefore, the hydraulic system must be designed so that the required hydraulic
pressure is regulated automatically by the hydraulic system during the closing times.
• If thermal expansion causes the filter pack to expand, the resulting excess pressure
must be relieved with a discharge valve.
• The closing force must not exceed the ratio calculated from the permissible
operating pressure and the operating temperature.
Therefore, we differentiate between the required closing force [F
min
] and the
maximum permissible closing force [F
max
].
Note
Should operating conditions exist which are not explained here, please contact LENSER
Filtration.
Your specific questions will be answered individually by LENSER Filtration experts.
WARNING
