Device for continuous filtration of material blends
A device for the continuous filtration of material blends, in particular for separating impurities from plastic melts. A housing has a hollow cylindrical filter disposed inside. An inside chamber is disposed inside the filter. An annular chamber is defined by the outer surface of the filter and an inside wall of the housing. A cleaning device removes the impurities retained on the filter by a motor driving about an axis coupled to pivot the filter inside the housing. The cleaning device has at least one wiper for removing in the radial direction impurities retained on the filter. A conveying device transports off the impurities removed from the filter by the wiper. The motor-driven filter and the conveying device are driven separately of each other.
1. A device for the continuous filtration of material blends, in particular for separating impurities from plastic melts, comprising a housing; a hollow cylindrical filter disposed inside the housing; an inside chamber disposed inside the filter; an annular chamber defined by the outer surface of the filter and an inside wall of the housing; a cleaning device for removing the impurities retained on the filter; a motor drive about an axis coupled to pivot the filter inside the housing; the cleaning device being comprised of at least one wiper for removing in the radial direction impurities retained on the filter and a conveying device for transporting off the impurities removed from the filter by the wiper, and wherein the motor-driven filter and the conveying device are driven separately of each other.
2. A device as in claim 1 , wherein the wiper is disposed at an oblique angle with respect to the filter.
3. A device as in claim 1 , wherein the wiper is disposed at an angle of pitch (α) with respect to a median plane of the filter.
4. A device as in claim 3 , wherein the angle of pitch (α) of the wiper can be changed.
5. A device as in claim 1 , wherein the wiper is disposed on a shaft that is pivotably disposed inside the housing.
6. A device as in claim 1 , wherein the conveying device is a motor-driven conveying screw that is disposed parallel to the axis of rotation of the filter.
7. A device as in claim 6 , wherein the rotational speed of the filter and the rotational speed of the conveying device are controllable separately of each other.
8. A device as in claim 6 , wherein the wiper is disposed in the immediate vicinity of the conveying screw.
9. A device as in claim 1 , wherein the filter comprises a filter tube supported by a supporting body, the filter tube having a plurality of thru openings that widen in the direction of flow.
10. A device as in claim 9 , wherein the supporting body comprises several circumferential collecting grooves with narrow rib-like elements disposed in between that support the filter tube.
11. A device as in claim 1 , wherein the filter is removably mounted on a carrier shaft that is pivotably disposed in the housing.
12. A device as in claim 11 , wherein the carrier shaft has several collecting slots that form the inside chamber.
13. A device as in claim 1 , wherein the wiper is a scraper knife that is pressed against the filter by means of a spring.
14. A device as in claim 1 , wherein the wiper is a spring blade.
15. A device as in claims 6 , wherein the filter and the conveying device have one of identical and opposite directions of rotation.