The filter consists of a filter container of special construction which is able to resist the filtering pressure without the use of stays. The shape of the filter ensures a uniform distribution of the unfiltered juice over the filter surface and furthermore an easy draining of the sludge without residue after cleaning.
The filter is provided with 32 identical frames consisting
of wire netting made of stainless steel.
The frames are placed in two rows in the filter with the outlet from each frame at the outer side of the filter. An inspection glass is placed at each outlet.
All outlets from the filter frames are collected in a triangular pipe around the filter which also serves as support for the filter.
The filter is provided with a top cover fastened by means of bolts.
From the filter the sludge is drained into a hydrophore below the filter. Level transmitter is placed in the hydrophore and used for controlling the amount of sludge taken out of the filter at each draining.
When the automatic valves are switched back to filtering position, the sludge is pressed out of the hydrophore by means of compressed air and delivered either into the sludge tank for vacuum filters or returned to preliming.
This method of pumping is used partly because it breaks down the sludge structure very little and thus maintains the highest possible filtration quality, and partly because it works without difficulty even with very high sludge concentrations.