Membrane Filter Elements
Status: 06/2001/01 Operating Manual 27
6.2.1 Precoat filtration
With precoat filtration, a thin layer of filter aid is allowed to build-up on the filter cloths of the
filter chambers. This method can achieve a better separation effect during filtration and/or
a better cake discharge at the end.
Diatomaceous earth, for example, is used as a filter aid.
6.2.2 Product filtration
The filter chambers are usually fed with pumps. There is a best possible pump size for each
installation.
Experience has shown that the dimensions of the feeding pump, depending on the product
composition and filtering speed, lie between 50 and 400 dm³ • h/m².
Information
• The required thickness of the filter aid layer must be determined individually for each
application.
• For a satisfactory effect, a uniform layer thickness is required for the entire filter
surface.
The concentration of filter aids in the precoating suspension and the precoating
quantity required in each case are determined empirically.
• The transition from precoat filtration to product filtration should take place without a
pressure drop to avoid disturbing the layer build-up.
• Please contact LENSER for additional information.
Information
• The feeding system must be designed so that no pressure pulsation or pressure dips
can occur. Otherwise uneven cake build-up, bent membrane filter elements and poor
filtration throughput will result.
• LENSER Filtration will be happy to offer advice on process optimisation.
