determination of limit dry solids contentReading time:
The apparatus used is the same as described in the filtrability test.
In this case it is required to use the piston to apply an homogeneous pressure on the filter cake avoiding it to crack.
The operating procedure is identical to the one described in filtrability test.
However, the following operations should be carried out after the sludge sample has been poured into the cell:
- with the purge valve removed the piston should be pushed down until it skims the surface of the sludge;
- re-insert the purge valve and tighten it down;
- follow the test procedure until the vertical asymptote of the curve is reached.
In practice, the filtration should be interrupted when the slope of the tangential at the point of interest is 5 times greater than the slope for the initial linear section. Determine the filter cake dry solids content at the pressure selected (at 105°C ± 2°C, until a constant weight is obtained).