In the backflush filter (10) according to the invention, in which the
flushing back of the filter inserts (15) which are received in several
filter chambers takes place by means of flushing filtrate loaded by
compressed air, the flush valve (35) and the mud drain valve (39) are
actuated by a common drive, whereas the valves or the valve bores (45,
46) are dimensioned in such a manner that the flush valve only releases
the connection to the filtrate chamber (19') of the filter inserts (15')
to be flushed back, when the mud drain valve has already at least
partially released the connection between the mud chamber (24') of the
affected filter chamber (14') with a mud outlet (40). By this, it is
ensured in a particularly simple manner that at the backflush process the
pressure level in the mud chamber has already dropped before the filtrate
for the backflush is loaded with compressed air (see FIG. 2).