Making the right Choice
The special requirements result from the way the filter press works: At the beginning of the dewatering process, a high flow rate is required, until the chambers between the filter plates gradually fill up with particulate matter resulting in what are called “filter cakes”. Due to the increasing resistance to flow as the filter cake builds up, the pump’s discharge pressure rises, while simultaneously the flow rate must be reduced, because the intake capacity of the filter press falls.
Piston Diaphragm Pump with Frequency Converter
ABEL piston diaphragm pumps can fulfil the demands for filter press feeding in various ways. Equipped with an analogue pressure sensor and a frequency converter, the initial flow rate, break-point and minimum flow rate can be easily set and also varied, if needed. This adaptability is a real plus compared to other types of feed pumps, whose pumping rate is, as a result of the design, dependent on counter pressure. Particularly when short filtration times and high solids content are important.
This type of control scheme is energy-saving and allows for individual adjustment, even with changing slurries, to reach optimum filtration results.
ABEL CM Series with Diaphragm Stroke Control
If sensitive electronics are to be avoided, ABEL offers pumps with an internal diaphragm stroke control. With this option, the volume conveyed of the piston diaphragm pump is not achieved by stroke number reduction (via VFD), but rather mechanically by reducing the membrane stroke length. This is a simple, long-term and cost-effective alternative solution.