| 摘要 |
<p>A filtration method has the step of feeding liquid to be filtered into a filter medium (1) between a fixed plate (2) and a movable plate (4); and reducing capacity of a filter chamber (80) formed by the medium (1) by moving the movable plate (4) in a direction in which the movable plate (4) presses the fixed plate (2) through the medium (1) so as to perform expressing filtration of the liquid and to produce cake (49). The reducing step has the step of alternately repeating at least one time an expressing pressure-increasing process for increasing pressure in the liquid in the medium (1) by a specified increment in the filtration of the liquid, and an expressing pressure-maintaining process for maintaining the pressure constant during a specified period, so that the filtration is performed under a specified pressure corresponding to a desired water content of the cake (49) to produce the cake (49). A filter press (3) for employing the method has the medium (1) arranged between the fixed plate (2) and the movable plate (4) capable of approaching and moving away from the fixed plate (2). The press (3) has a driving device for driving the movable plate (4) to approach and move away from the fixed plate (2); a pressure sensor (60) arranged at one of the movable plate (4) and the fixed plate (2) and measuring pressure in the chamber (80); and a control unit (61) for controlling the expressing filtration of the liquid by control of drive of the driving device on the basis of a signal outputted from the sensor (60).</p> |
