Filter Press Feeding - FPPU Brief Process Description
With an increasing layer of solids on the filter cloths of a filter press, the filtration pressure will rise when the conveying capacity of the feeding pumps stays constant. This causes premature compacting of the layer of solids that is very thin at first, and thus to an unfavourable throughput with accordingly long filtration times. The draining rate (dry matter contents) is also affected. For this reason, premature compacting of the layer of solids must be prevented. This is possible by reducing the delivery rate. The filtration pressure can be used as the process dimension for compacting.
Depending on the filtration pressure, the feed rate to the filter press must be reduced appropriately with increasing pressure. The ratio of conveying capacity to pressure is adjustable within extended limits for the developed controller to be able to adapt to the different dewatering characteristics of the respective products.
A complete filtration cycle is completed when the final pressure that must be set manually has been exceeded.
The seepex FPPU controller controls the filter press process as follows:
Pressure-dependent control of the prefeeding and high pressure pump
Volume-dependent control of the polymer pump
Temperature control of the stator (dry running protection device TSE)
Overpressure protection of the piping
It is available in the following two variants.
Variant FPPU: PLC with integrated LC-display. By use of additional modules this control variant can be extended to the feeding of four filter presses. A bus connection to a master PLC is already included in the software. Storage space is available for max. 20 user-specific characteristic filling curves. Variant LC-FPPU: Solution for networking and parameterizing up to three frequency inverters via CAN bus. Storage space is available for max. 9 user-specific characteristic filling curves.
