Making the right Pump Choice
The particular, demands on the feed pump result from the way the filter press works: At the beginning of the filtration process, a high flow rate is required from the feed pump, until the chambers between the filter plates gradually fill up with particulate matter resulting in what are called “filter cakes”. Due to the resultant 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 these 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, much more importantly, also varied, if need be. This adaptability is a real plus compared to other types of feed pumps, whose pumping rate is, as a result of the pump’s construction, dependent on counter pressure. Particularly when short filtration times and high solids content are important.
This type of control scheme for filter press feed is energy-saving, and at the same time, allows for individual adjustment, even with changing slurries, to reach optimum filtration results.
Compact Diaphragm Pump with Diaphragm Stroke Control
If sensitive electronics are to be avoided, ABEL offers filter press feed pumps with an internal diaphragm stroke control. With this option, the pumping rate of the piston diaphragm pump under increasing counter-pressure is not achieved by stroke number reduction (via VFD), but rather mechanically by reducing the membrane stroke length. This is simple, long-term, and cost-effective alternative solution, particularly for small chamber filter presses.