Liquid purification or separation – Filter – With residue removing means or agitation of liquid
Patent
1995-04-12
1997-06-03
Lithgow, Thomas M.
Liquid purification or separation
Filter
With residue removing means or agitation of liquid
21033301, 2103331, 210415, B01D 2968, B01D 2901, B01D 2939, B01D 35027
Patent
active
056350660
DESCRIPTION:
BRIEF SUMMARY
SPECIFICATION
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national phase of PCT/DE 94/00704 filed June 1994 and based, in turn, upon German National application P 43 20 952.1 under the international convention.
FIELD OF THE INVENTION
The present invention directs to a pressure filter comprising a fluid compartment with a fluid inlet, at least one filter surface within the fluid compartment having a plurality of apertures, one side of the filter surface being restricted by the fluid compartment and the other side thereof being restricted by a filtrate compartment having a filtrate outlet, and backwashing means with a slat-like or plate-like backwashing head sweeping over the filter surface and sealing a part of the filter surface with respect to the fluid compartment, the backwashing head having a backwashing compartment restricting at least one suction chamber open in a slot-like manner to the filter surface, the backwashing compartment having a reject drain connected thereto.
BACKGROUND OF THE INVENTION
A pressure filter of the above-described type is known from EP 0 479 077 A1. This pressure filter works with a continuous cleaning of the filter surface and is especially destined for the separation of solids from suspensions. To the fundamental construction of such a pressure filter a plurality of pressure-tight filter elements separating the fluid compartment from the filtrate compartment and forming the filter surface and the backwashing means connected to the reject drain and having a backwashing head sealing a part of the filter surface with respect to the fluid compartment belong. The backwashing head and the filter surface are movable with respect to one another. The fluid to be filtered is supplied to the pressure filter with a pressure P.sub.1 and acts on the filter elements with this pressure P.sub.1 in the fluid compartment. The filtrate is drained from the filtrate compartement with a lower pressure P.sub.2. In the reject drain and backwashing compartment restricted by the backwashing head a pressure P.sub.3 is adjustable which is always smaller than the pressure P.sub.2 in the filtrate compartment. A filtration occurs on account of the pressure difference between the pressure P.sub.1 of the fluid compartment and the pressure P.sub.2 of the filtrate compartment, wherein solids are deposited on the filter surface and form a cover layer. This cover layer is continuously cleaned by backwashing, i.e. a conversion of the flow direction through the filter elements. The backwashing occurs at that portion of the filter surface which is sealed by the backwashing head with respect to the fluid compartment with a pressure difference between the pressure P.sub.2 in the filtrate compartment and the pressure P.sub.3 in the backwashing compartment. The filtration process at the remaining filter surface of the pressure filter is not influenced by the backwashing.
According to the known pressure filter the backwashing compartment has at least one suction chamber open to the filter surface in a slot-like manner. This suction chamber is formed as elongated chamber extending from a central drive shaft for the backwashing head radially outwardly. Upon rotation of the backwashing head the slot-like aperture sweeps over the filter surface as a radial beam emanating from the center of the pressure filter. Now, it became evident that difficulties result to assure at each radial point of the slat-like or plate-like backwashing head the same pressure against the filter surface. So, on account of the central support of the backwashing head, the pressure is higher in the central range than in the radial outer range. Especially, it became evident in practice that the radial outer end portions of the slat-like or plate-like head tend to lift off from the filter surface so that the correct realization of the backwashing progress can no more be guaranteed.
OBJECT OF THE INVENTION TO PROVIDE A PRESSURE
It is the object of the invention to provide a pressure filter of the cited type according to wh
REFERENCES:
patent: 2802572 (1957-08-01), Jalkanen
patent: 2834474 (1958-05-01), Jalkanen
patent: 3640395 (1972-02-01), Kinney
patent: 4085051 (1978-04-01), Karinsky
patent: 4162219 (1979-07-01), Miropolsky
patent: 4303522 (1981-12-01), Ducasse
Dubno Herbert
Lithgow Thomas M.
Maurer Mike
LandOfFree
Pressure filter with a back-flushing head exerting a uniform con does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressure filter with a back-flushing head exerting a uniform con, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressure filter with a back-flushing head exerting a uniform con will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-388656