| 摘要 |
PURPOSE:To realize automatic release of biting status of a rotary valve for use in dust disposal and the like by switching a flow by means of a switching device according to an abnormality signal of rotatory condition detector and putting the rotary valve in one reverse and normal rotation. CONSTITUTION:When biting status occurs in a rotary valve 3 and the number of rotation is reduced, the period of a pulse from an adjacent switch R2 is lengthened. In case said period exceeds the set time of a dial 22, an integration circuit 19 puts SCR circuit 29 to ON state to operate a self-recovery circuit 6. Due to this operation, a switching device 5 is switched to a bypass 4 side by means of a motor cylinder 13, and at the same time, a motor 25 is put in at least one reverse rotation and also in normal rotation. If an ordinary rotation is recovered during the normal rotation, the pulse period of the adjacent switch R2 turns below a predetermined value, and the self-recovery circuit 6 allows the switch device 5 to return and make the rotary valve 3 to continue normal rotation. Thus, the biting status can be automatically released without stopping the flow. |
