EP0158529A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pressure filter
Assignee: Dorr Oliver Inc
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Filing: 1985-04-04
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Granted: —
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Expires: 2005-04-04
Abstract
Abstract A pressure filter for separating a liquor from mud liquor slurry and for concentrating a filter cake as a heavy slurry discharge, comprising a tank 11 having a ring of filter elements 15 supported by a plate 16 which separates the filter tank from a filtrate chamber 20. The feed enters the tank under pressure through an enlarged feed cylinder tube 29 located in the centre of the ring of filter elements. In the backwashing mode of operation the feed rate is maintained or increased to assist in displacing filter cake from the filter element.
Inventors
- 👤 Gordon Spilkin
- 👤 Jack Harold Eichler
- 👤 Peter Kos
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 20:33
CPC Classifications
B; B01; B01D; B01D36/00; B01D36/001; B01D29/00; B01D29/11; B01D29/114; B01D29/50; B01D29/52; B01D29/62; B01D29/66; B01D29/88; B01D29/885; B01D29/90; B01D29/92; B01D2201/00; B01D2201/04; B01D2201/043; B01D2201/0446; B01D2201/08; B01D2201/085
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
162 words
A pressure filter for separating a liquid from a liquid solid slurry solution and thickening a solids slurry for discharge as underflow from said filter, comprising a vertical cylindrical tank (11), a plurality of tubular filter elements (15) suspended in spaced and parallel vertical relationship from one side of a circular support plate (16) disposed in the upper portion of said tank, a filtrate receiving chamber (20) located at the opposite side of said support plate for receiving filtrate from said filter elements, a sump discharge outlet (35) at the base of said tank for discharging the thickened solids slurry removed from said filter elements, and a feed slurry inlet (27) to said tank characterised by feed distribution means (26) in said tank and including a feed tube (29) connected to said feed slurry inlet to said tank, said feed tube having a discharge end positioned adjacent said upper ends of said filter elements spaced from the undersurface of said support plate.
Claim 2
Dependent Claim
162 words
A pressure filter for separating a liquid from a liquid solid slurry solution and thickening a solids slurry for discharge as underflow from said filter, comprising a vertical cylindrical tank (11), a plurality of tubular filter elements (15) suspended in spaced and parallel vertical relationship from one side of a circular support plate (16) disposed in the upper portion of said tank, a filtrate receiving chamber (20) located at the opposite side of said support plate for receiving filtrate from said filter elements, a sump discharge outlet (35) at the base of said tank for discharging the thickened solids slurry removed from said filter elements, and a feed slurry inlet (27) to said tank characterised by feed distribution means (26) in said tank and including a feed tube (29) connected to said feed slurry inlet to said tank, said feed tube having a discharge end positioned adjacent said upper ends of said filter elements spaced from the undersurface of said support plate.
Claim 3
Dependent Claim
45 words
The pressure filter of claim 1 characterised in that said filter elements (15) are arranged in a ring about the circumference of said undersurface of said support plate and wherein said feed tube (29) is positioned at the center of said ring of filter elements.
Claim 4
Dependent Claim
39 words
The pressure filter of claim 2 characterised in that said feed tube (29) includes a cylindrical member having a diameter approximately equal to the radius of said filter tank and extending vertically approximately the height of said filter elements.
Claim 5
Dependent Claim
62 words
The pressure filter of claim 3 characterised in that said filter elements (15) comprise perforated tubular members having filter socks disposed about the outer surface thereof and having an end open to said filtrate receiving chamber (20) and wherein said tubes are located between said inner wall of said filter tank wall and the outer wall of said feed tube cylinder (29).
Claim 6
Dependent Claim
63 words
The pressure filter of any preceding claim characterised in that means (34, 36) are provided to permit discharge of the filtrate in said filtrate chamber to backflow to discharge filter cake from said filter elements and wherein means (33) are provided in said tank to return feed slurry'to a feed slurry feed tank (24) during said displacement of said cake from filter elements.
Claim 7
Dependent Claim
24 words
The pr3ssure filter of claim 5 characterised in that said feed slurry return means include a flushing pipe (31) located beneath said feed inlet.
Claim 8
Dependent Claim
55 words
The presasure filter of claim 6 characterised in that a displacement zone (A) for receiving cake from said filter elements is provided in said tank between the ends of said filter elements (15) and said flushing pipe extending a predetermined distance to allow cake to discharge from said filter elements without entering said flushing pipe.
Claim 9
Dependent Claim
30 words
The pressure filter of claim 6 or 7 characterised in that said flushing pipe comprises a barometric leg for providing a vacuum assist during the backwashing of said filter element.
Claim 10
Dependent Claim
27 words
The pressure filter of claim 8 wherein said barometric leg has one end immersed in the feed slurry tank and the opposite end in said filter tank.
Claim 11
Dependent Claim
25 words
The pressure filter of claim 9 characterised in that said opposite end of said barometric leg is provided with a funnel shaped end portion (33).
Claim 12
Dependent Claim
37 words
The pressure filter of any of claims 6 to 10 characterised in that normally closed valves (34, 36) are provided in said flushing line and said sump outlet and are opened for backwashing of said filter elements.
Claim 13
Independent Claim
190 words
A method of continuously thickening a suspension of solids by filtration under pressure to deliver a filtrate liquor and a thickened sludge underflow with periodic backwashing of the filter media, characterised by the steps of establishing a pressure filtration zone in a filter tank defined by the height of elongated filter elements suspended in said tank having their upper ends attached to a plate so that filtrate from said elements passes upwardly from said filtration zone into a filtrate compartment, establishing a filter cake displacement zone in the area between the opposite ends of said filter elements and a barometric discharge leg, feeding a slurry solution to said tank at a high rate of flux for a predetermined period wherein feed slurry occupies said displacement zone during a filtration process, providing a supply of backwash filtrate to said filtration zone to displace cake from said filter elements to said displacement zone while continuing to maintain a feed rate slurry to aid in said displacement, and removing feed slurry in the displacement zone during said backwashing step, and passing thickened slurry to a discharge sump upon completion of said backwashing step.
Claim 14
Independent Claim
190 words
A method of continuously thickening a suspension of solids by filtration under pressure to deliver a filtrate liquor and a thickened sludge underflow with periodic backwashing of the filter media, characterised by the steps of establishing a pressure filtration zone in a filter tank defined by the height of elongated filter elements suspended in said tank having their upper ends attached to a plate so that filtrate from said elements passes upwardly from said filtration zone into a filtrate compartment, establishing a filter cake displacement zone in the area between the opposite ends of said filter elements and a barometric discharge leg, feeding a slurry solution to said tank at a high rate of flux for a predetermined period wherein feed slurry occupies said displacement zone during a filtration process, providing a supply of backwash filtrate to said filtration zone to displace cake from said filter elements to said displacement zone while continuing to maintain a feed rate slurry to aid in said displacement, and removing feed slurry in the displacement zone during said backwashing step, and passing thickened slurry to a discharge sump upon completion of said backwashing step.
Claim 15
Dependent Claim
46 words
The method of claim 12 characterised in that a vacuum assist is provided to said backwashing step by a barometric leg and wherein said feed slurry in said displacement zone is removed from said tank through said barometric leg during said backwashing of the filter element.
Claim 16
Dependent Claim
22 words
The method of claim 12 or 13 characterised in that the filtration and thickening backwash and discharge cycle is about 30 seconds.
Claim 17
Dependent Claim
20 words
The method of claim 14 characterised in that said backwash and displacement portion of said cycle is about 5 seconds.
Claim 18
Dependent Claim
24 words
The method of claim 15 characterised in that the rate of slurry feed to said tank is increased during said backwash and displacement portion.
References Cited (Backward Citations)
No citation records indexed.
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