| 摘要 |
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). The invention relates to a backwash filter having at least two filter chambers which are arranged on a common control housing (3) which accommodates a control element (9) which is operated by a control drive (20) and by means of which the filter chambers can be switched individually from filter operation to backwash operation and vice versa, and having a pressurized gas feedline for the pressurized gas-aided backwash operation. According to the invention, the filter inserts (2) of the filter chambers (1) are immersed into the control housing (3), preferably by a length which corresponds to at least approximately 1/3 to ½ of its overall length. In the control housing (3), the medium space (10) is expediently arranged above the filtrate space (11), the filter inserts (2) being immersed into the medium space (10). The slurry blow-off valve (8) and the valve serving for the feeding of the pressurized gas are separated in construction from the control element (9), the slurry blow-off valve (8) preferably being situated in the horizontal position at the foot of the control housing.
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