US 5,707,517 A · Immersible rotary disc filtration device

Abstract

Rotary disc filtration devices and filtration processes using those devices are disclosed. The devices have one or more fluid filtration gaps into which fluid to be filtered into permeate and retentate is placed. Each fluid filtration gap is defined by a disc and a filter, one of which rotates with respect to the other. The filter is carried on a filter member. The discs and interleaved filter members may be suspended from the top of the device, the top may rest on a vessel containing the fluid to be filtered, the discs may be attached to a single shaft for rotation, and the filter members may be suspended from a sleeve around the shaft, which sleeve keeps the filters centered with respect to the discs. Removal of the device's top removes the discs and filter members together, facilitating maintenance. Each filter member may have a peripheral lip and the lips of adjacent filter members may be sufficiently close to one another to substantially restrict the flow of retentate out of the fluid filtration gap. Retentate flowing out of each fluid filtration gap may be directed into the vessel to counteract the tendency of the fluid in the vessel to rotate in the same direction as the discs are rotated, or the retentate may be recycled directly to the fluid filtration gaps. The liquid level in the vessel may be held constant using a dual-pipe system and three-head peristaltic pump.

Claims108

Dependent claims

A rotary disc filtration device for filtering fluid from a body of fluid having an uppermost fluid level into permeate and retentate, the device comprising:

(a) a first member;
(b) one or more discs, each disc being suspended from the first member;
(c) one or more filter members, at least one filter member having a filter, each filter being oppositely disposed to a disc to define a fluid filtration gap therebetween in which gap the fluid to be filtered is placed during filtration, there being one or more fluid filtration gaps, fluid passing through each filter from a fluid filtration gap being the permeate and fluid not passing from a fluid filtration gap through a filter being the retentate, each filter member being suspended from the first member;
(d) rotating means for rotating at least one of each disc and filter defining a fluid filtration gap with respect to each other;
and
(e) rotatable suspension means for suspending from the first member the one or more discs or filter members so that at least one of each disc and filter defining a fluid filtration gap can rotate with respect to each other, the rotatable suspension means being above the uppermost fluid level of the body of fluid to be filtered.

3 more elements

A rotary disc filtration device for filtering fluid from a body of fluid having an uppermost fluid level into permeate and retentate, the device comprising:

(a) a first member;
(b) one or more discs, each disc being suspended from the first member;
(c) one or more filter members, at least one filter member having a filter, each filter being oppositely disposed to a disc to define a fluid filtration gap therebetween in which gap the fluid to be filtered is placed during filtration, there being one or more fluid filtration gaps, fluid passing through each filter from a fluid filtration gap being the permeate and fluid not passing from a fluid filtration gap through a filter being the retentate, the filter member defining at least one fluid filtration gap having restriction means for restricting the flow of retentate out of at least one fluid filtration gap into the body of fluid;
(d) rotating means for rotating at least one of each disc and filter defining a fluid filtration gap with respect to each other;
and
(e) rotatable suspension means for suspending from the first member the one or more discs or filter members so that at least one of each disc and filter defining a fluid filtration gap can rotate with respect to each other.

3 more elements

A rotary disc filtration device for filtering fluid from a body of fluid having an uppermost fluid level into permeate and retentate, the device comprising:

(a) a first member;
(b) one or more discs, each disc being suspended from the first member;
(c) one or more filter members, at least one filter member having a filter, each filter being oppositely disposed to a disc to define a fluid filtration gap therebetween in which gap the fluid to be filtered is placed during filtration, there being one or more fluid filtration gaps, fluid passing through each filter from a fluid filtration gap being the permeate and fluid not passing from a fluid filtration gap through a filter being the retentate;
(d) rotating means for rotating at least one of each disc and filter defining a fluid filtration gap with respect to each other;
(e) rotatable suspension means for suspending from the first member the one or more discs or filter members so that at least one of each disc and filter defining a fluid filtration gap can rotate with respect to each other;
(f) means for locating at least one of the one or more fluid filtration gaps within the body of fluid, the filter member defining that fluid filtration gap having restriction means for restricting the flow of retentate out of that fluid filtration gap into the body of fluid;
and
(g) feed fluid means for placing fluid from the body of fluid into one or more fluid filtration gaps, the feed fluid means comprising (i) an opening in at least one filter member for the inflow of fluid from the body of fluid, (ii) means for fluidly connecting the opening in the at least one filter member with at least one fluid filtration gap, and (iii) means to position the at least one filter member in the body of fluid so that fluid to be filtered can flow from the body of fluid through the opening in the at least one filter member to the at least one fluid filtration gap.

5 more elements

A rotary disc filtration device for filtering fluid from a body of fluid having an uppermost fluid level into permeate and retentate, the device comprising:

(a) a removable first member;
(b) one or more discs, each disc being rotatably suspended from the removable first member by rotatable suspension means, the rotatable suspension means being above the uppermost fluid level of the body of fluid to be filtered;
(c) one or more filter members, at least one filter member having a filter, each filter being oppositely disposed to a disc to define a fluid filtration gap therebetween in which gap the fluid to be filtered is placed during filtration, there being one or more fluid filtration gaps, fluid passing through each filter from a fluid filtration gap being the permeate and fluid not passing from a fluid filtration gap through a filter being the retentate, each filter member being non-rotatably suspended from the removable first member;
(d) rotating means for rotating at least one disc defining a fluid filtration gap, the rotating means comprising a shaft having a longitudinal axis on which shaft the one or more discs are mounted;
(e) means for locating at least one of the one or more fluid filtration gaps within the body of fluid, the filter member defining that fluid filtration gap having near its periphery restriction means for restricting the flow of retentate out of that fluid filtration gap into the body of fluid;
(f) feed fluid means for placing fluid from the body of fluid into one or more fluid filtration gaps, the feed fluid means comprising (i) an opening in at least one filter member for the inflow of fluid from the body of fluid, (ii) means for fluidly connecting the opening in the at least one filter member with at least one fluid filtration gap, and (iii) means to position the at least one filter member in the body of fluid so that fluid to be filtered can flow from the body of fluid through the opening in the at least one filter member to the at least one fluid filtration gap;
and
(g) means for maintaining the one or more filter members substantially centered with respect to the longitudinal axis of the shaft.

5 more elements

Dependencies are inferred from the claim text.

Immersible rotary disc filtration device

Life of this patent

Immersible rotary disc filtration device

Life of this patent

Abstract

Claims108