초록 ▼

A filter for flowing polymer having a filter element progressively advanced between an on-stream position communicating between the upstream and downstream passages and a backflush position. In the latter position, filtered polymer is forced through a segment of the element in the direction opposite

A filter for flowing polymer having a filter element progressively advanced between an on-stream position communicating between the upstream and downstream passages and a backflush position. In the latter position, filtered polymer is forced through a segment of the element in the direction opposite to on-stream flow. The filter is advanced in steps alternately with the energization of a pump for creating the backflush pressure. The steps are determined to cause each filter portion to remain in the backflush position for at least two consecutive steps.

대표청구항 ▼

A filter for flowing polymer comprising, in combination, filter means including an element having a foraminate filter area, a body defining upstream and downstream passages and supporting the filter means rotatably therein with said area of the filter element between said passages, said body having

A filter for flowing polymer comprising, in combination, filter means including an element having a foraminate filter area, a body defining upstream and downstream passages and supporting the filter means rotatably therein with said area of the filter element between said passages, said body having partition means defining a downstream chamber communicating with a segment of said area and an upstream chamber substantially sealed from the upstream passage and extending over and communicating with a portion of said area including said segment, a check valve connecting the downstream chamber with the downstream passage, a pump connected to the downstream chamber and having a power source reciprocating the pump to lower the downstream chamber pressure thereby drawing polymer thereinto through the check valve, and to raise said pressure thereby forcing the polymer through said segment into the upstream chamber, exhaust means connecting between the upstream chamber and the exterior of the body, and advancing means rotating said filter means to advance said segment out of communication with said chambers and to advance another segment of said area into communication with said chambers.