Filter and method of cleaning the filter

Claim 2

A process according to claim 1, in which, after the filter has been cleaned, removing the sludge, released from the inlet side of the filter by the cleaning fluid, from the base of the inlet side of the filter apparatus by a pipe attached to the base, by means of a gas under pressure in the inner volume of the apparatus.

Claim 3

A process according to claim 1, in which, after the filter has been cleaned, removing the sludge, released from the inlet side of the filter by the cleaning fluid, from the base of the inlet side of the filter apparatus by a pipe attached to the base, by means of a gas under pressure in the inner volume of the apparatus, and in which the gas is at least partially air which is supplied to the filter apparatus for mixing the sludge with the cleaning fluid at the inlet side beneath the level of the cleaning fluid accumulated at the base of the inlet side of the apparatus.

Claim 4

A process according to claim 1, in which the cleaning fluid and gaseous medium are supplied from the container by a feedpipe to the outlet side of the filter, and in which the filling of the separate container, with the feedpipe closed, is carried out at least partially with the cleaning fluid, heating the cleaning fluid to a temperature above its boiling point at normal pressure and then opening the feedpipe so that the pressure of the cleaning fluid falls, a part of the cleaning fluid being vaporized in the separate container and this vapor then forms the gaseous medium used for supplying the cleaning fluid to the filter apparatus.

Claim 5

A process according to claim 5, in which water is used as the cleaning fluid and the gaseous medium is formed from the water vapor.

Claim 6

A process according to claim 5, in which water is used as the cleaning fluid and the gaseous medium is formed from the water vapor, and wherein the water is heated in the separate container to a temperature exceeding 140* C.

Claim 7

A filter apparatus, comprising at least one filter, a separate container connected by a feedpipe to the outlet side of the filter apparatus, a stop valve in the feedpipe, and means for causing a gaseous medium under excess pressure to displace a cleaning fluid from the container into the filter apparatus, the filter being a candle filter with a plurality of filter candles and the filter candles are provided with means for distributing the cleaning fluid, which during the cleaning operation flows from an outlet side of the filter apparatus into the interior of the candles, on the inner surface of the permeable and filtering parts of the candles, the distributing means are provided for each candle comprising a nozzle-shaped constriction at the outlet from the candle and a deflecting body attached at a distance from the constriction inside the candle, the body serving to deflect cleaning fluid, which, during the cleaning operation, flows through the constriction in the form of a jet to all sides in the direction of the inner walls of the candle, and an annular closed loop-gap provided between the deflecting body and the inner wall of the candle, down through which the cleaning fluid distributed along the inner wall of the candle by the deflecting body, can run, and in which the deflecting body is a round and flat deflecting plate mounted at 2 to 5 cm. from the edge of the permeable filtering part of the candle and perpendicular to the axis of the candlE.

Claim 8

A filter apparatus, comprising at least one filter, a separate container connected by a feedpipe to the outlet side of the filter apparatus, a stop valve in the feedpipe, and means for causing a gaseous medium under excess pressure to displace a cleaning fluid from a container into the filter apparatus, the filter being a candle filter with a plurality of filter candles and the filter candles are provided with means for distributing the cleaning fluid, which during the cleaning operation flows from an outlet side of the filter apparatus into the interior of the candles, on the inner surface of the permeable and filtering parts of the candles, the distributing means for each candle comprise a nozzle tip at the outlet side of the end of the candle and projecting into the candle, the tip having a number of nozzle openings directed toward the surrounding part of the inner wall of the candle.

Claim 9

A filter apparatus, comprising at least one filter, a separate container connected by a feedpipe to the outlet side of the filter apparatus, a stop valve in the feedpipe, and means for causing a gaseous medium under excess pressure to displace a cleaning fluid from the container into the filter apparatus, the filter being a candle filter with a plurality of filter candles and the filter candles are provided with means for distributing the cleaning fluid, which during the cleaning operation flows from an outlet side of the filter apparatus into the interior of the candles, on the inner surface of the permeable and filtering parts of the candles, the filter candles are attached to a wallplate, located between the inlet and outlet sides of the filter apparatus, by means of a screw penetrating the wallplate and screwed into the end plate at the outlet side of the candle, said screw projecting into the candle with an attachment at the front which forms the nozzle tip and is provided with a blind hole extending from the top of the screw to the attachment, as well as with nozzle openings issuing radially from the blind hole in the region of the attachment.