| 摘要 |
<p>On piston diaphragm chamber filter presses the usual soft diaphragm is replaced by a firm material capable of to and fro motion in piston fashion without deformation, pref. hard rubber, extended integrally by a yielding material to compensate for such movement in bellows fashion, pref. soft rubber of suitable elasticity forming also the seal between each pair of plates, and pref. permanently attached thereto, pref. by vulcanisation, so forming a complete chamber unit. Suitable grades of plastics may also be employed. Each such diaphragm may be sub-divided into several piston- andyielding areas. With plate and frame presses, the soft rubber extensions to the piston(s) are attached between plates and frames. Provision of guide straps between filter plates and such pistons to ensure that piston movement is parallel to its plate is embodied. Non-deforming piston diaphragms overcome voids in chambers, blocking of filtrate ports, excessive strain hitherto experienced with soft diaphragms.</p> |
