Membrane Filter Elements
18 Operating Manual Status: 06/2001/01
6.1.1 Determining the closing force for standard filter elements up to 16 bar
To determine the closing force for standard membrane filter elements:
1. Refer to the graphs (Appendix, Graph 11+12, page 62) to read off the permissible
pressures in dependence of the operating temperature.
Make sure to take the material of the filter element into account!
2. Establish the maximum permissible operating pressure.
- The actual operating pressure must be less than or equal to the maximum
permissible operating pressure.
- The closing force is dependent on the size of the filter elements.
- Examples explain how to read off the values from the graphs.
3. Now determine the required closing force [F
min
] and the maximum permissible closing
force [F
max
] for the respective filter element pack from the graphs (see Appendix).
4. Calculate the exact closing forces as a function of the actual operating pressure [p] with
the formulae [1] and [2]:
Warning
Make sure that:
• the required closing force is permissible for your filter press frame.
• the required closing force remains constant during the closing times (is within the
specified amounts for F
min
and F
max
).
- An insufficient closing force results in leakage.
- Excessive closing force may damage the filter elements and the filter press frame.
Improper operation may cause property damage and injuries.
• the closing force does not exceed the ratio calculated from the permissible operating
pressure and the operating temperature.
• when the filter press is not in operation, no closing force is applied to the filter
elements.
- There is a danger that, as the result of temperature fluctuations, changes in the
length of the plate pack may occur which cannot be compensated by the closing
mechanism, e.g. the hydraulic system.
• if the filter press is to be closed without operating it, the hydraulic system continues
to operate.
- However, the maximum permissible closing force must not be applied for an
extended period, e.g. for longer than one (1) day, without operating the filter press.
- In this case, permanent deformations to the filter elements may occur which lead to
malfunctions of the filter elements and the filter press.
• no objects, including filter cake residues or even persons, are caught while closing
the filter press.
Improper operation may cause property damage and injuries.
• the general accident prevention regulations, such as the light curtain, release cord
etc. are observed.
The employer's liability insurance association has published corresponding accident
prevention regulations for filter presses. Ask your safety expert about them.
WARNING
