| 摘要 |
PURPOSE:To hold a flow rate of fluid constant by flushing a filter by operating a lower limit contactless switch by detecting by a raise in pressure of fluid in a duct due to clogging caused by deposition of powder in a filter bag by a pressure detector. CONSTITUTION:Duct 10 is provided with variable fluid resistor 14, its driving motor and detector 16 for pressure in the duct, and between the driving motor and detector 16, control circuit 17 is further arranged. This resistor 14, having the shape of a circular damper in conformity with the section of duct 10, give resistance of various value to classified media flowing in duct 10 according to the circumferential rotation of the shaft. Then, classifier 1 operates and when powder is deposited in filter bag 11 to cause clogging, the pressure in duct 10 rises. Consequently, float 20 in channel-shaped glass pipe 18 is lowered and lower-limit contactless switch 22 is operated to flush the filter. Thus, the flow rate is held constant. |
