US3856674A — Filtering process and apparatus

Claim 1

Independent Claim 241 words

A PROCESS FOR FILTERING A SUBSTANCE FLOWING THROUGH A PASSAGE COMPRISING THE STEPS OF INTRODUCING A FILTER BY PASSING IT THROUGH INLET AND OUTLET PORTS FLANKING SAID PASSAGE SO THAT A PART OF THE FILTER EXTENDS ACROSS THE PASSAGE, FORCING THE SUBSTANCE THROUGH THE FILTER PART IN THE PASSAGE TO FILTER THE SUBSTANCE, PROVIDING A FLOWABLE SEALING SUBSTANCE IN SAID INLET AND OUTLET PORTS, MAINTAINING TEMPERATURE CONDITIONS AT SAID INLET AND OUTLET PORTS RESULTING IN THE FORMATION THEREIN OF SEALING PLUGS OF SAID FLOWABLE SEALING SUBSTANCE OF ADEQUATE RIGIDITY TO PREVENT SUBSTANTIAL LEAKAGE AT SAID PORTS OF THE SUBSTANCE BEING FILTERED, SUPPORTING AT LEAST SAID PART OF THE FILTER WHICH EXTENDS ACROSS THE PASSAGE BY MEANS OF A MOVABLE BACKING SUPPORT ADAPTED TO RECEIVE SUBSTANCE FILTERING THROUGH THE FILTER, EQUALIZING THE FORCE APPLIED TO THE BACKING SUPPORT AS THE RESULT OF A HYDROSTATIC PRESSURE DIFFERENTIAL ACROSS THE FILTER URGING THE FILTER AGAINST THE BACKING SUPPORT BY APPLYING TO THE BACKING SUPPORT A COUNTERACTING FORCE THEREBY AT LEAST TO REDUCE THE NET FORCE TENDING TO RESTRICT THE EASE OF MOVEMENT OF THE BACKING SUPPORT, EFFECTING MOVEMENT OF SAID FILTER THROUGH SAID PORTS TO INTRODUCE ANOTHER PART THEREOF INTO SAID PASSAGE UNDER CONDITIONS PROVIDING FOR MAINTENANCE OF SAID SEALING PLUGS, EFFECTING MOVEMENT OF SAID BACKING SUPPORT WITH SAID FILTER MOVEMENT SO THAT THE BAKCING SUPPORT SERVES AS A MOVING BEARING FOR THE FILTER, AND EXTRACTING SAID FILTERED MATERIAL RECEIVED IN THE BACKING SUPPORT.

Claim 2

Dependent Claim 241 words

A PROCESS FOR FILTERING A SUBSTANCE FLOWING THROUGH A PASSAGE COMPRISING THE STEPS OF INTRODUCING A FILTER BY PASSING IT THROUGH INLET AND OUTLET PORTS FLANKING SAID PASSAGE SO THAT A PART OF THE FILTER EXTENDS ACROSS THE PASSAGE, FORCING THE SUBSTANCE THROUGH THE FILTER PART IN THE PASSAGE TO FILTER THE SUBSTANCE, PROVIDING A FLOWABLE SEALING SUBSTANCE IN SAID INLET AND OUTLET PORTS, MAINTAINING TEMPERATURE CONDITIONS AT SAID INLET AND OUTLET PORTS RESULTING IN THE FORMATION THEREIN OF SEALING PLUGS OF SAID FLOWABLE SEALING SUBSTANCE OF ADEQUATE RIGIDITY TO PREVENT SUBSTANTIAL LEAKAGE AT SAID PORTS OF THE SUBSTANCE BEING FILTERED, SUPPORTING AT LEAST SAID PART OF THE FILTER WHICH EXTENDS ACROSS THE PASSAGE BY MEANS OF A MOVABLE BACKING SUPPORT ADAPTED TO RECEIVE SUBSTANCE FILTERING THROUGH THE FILTER, EQUALIZING THE FORCE APPLIED TO THE BACKING SUPPORT AS THE RESULT OF A HYDROSTATIC PRESSURE DIFFERENTIAL ACROSS THE FILTER URGING THE FILTER AGAINST THE BACKING SUPPORT BY APPLYING TO THE BACKING SUPPORT A COUNTERACTING FORCE THEREBY AT LEAST TO REDUCE THE NET FORCE TENDING TO RESTRICT THE EASE OF MOVEMENT OF THE BACKING SUPPORT, EFFECTING MOVEMENT OF SAID FILTER THROUGH SAID PORTS TO INTRODUCE ANOTHER PART THEREOF INTO SAID PASSAGE UNDER CONDITIONS PROVIDING FOR MAINTENANCE OF SAID SEALING PLUGS, EFFECTING MOVEMENT OF SAID BACKING SUPPORT WITH SAID FILTER MOVEMENT SO THAT THE BAKCING SUPPORT SERVES AS A MOVING BEARING FOR THE FILTER, AND EXTRACTING SAID FILTERED MATERIAL RECEIVED IN THE BACKING SUPPORT.

Claim 3

Dependent Claim 45 words

A process as claimed in claim 1 wherein the said counteracting force is developed as a result of a hydrostatic pressure differential across at least one other filter supported upon said movable backing support urging said at least one other filter against the backing support.

Claim 4

Dependent Claim 30 words

A process as claimed in claim 1 wherein the said movement of the backing support is effected at least in part as the result of a mechanical drive applied thereto.

Claim 5

Dependent Claim 62 words

A process as claimed in claim 1 wherein the said filter is keyed to the sealing plug within the outlet port and wherein the hydrostatic pressure of the substance within said passage acting upon the sealing plug within the outlet port is utilized to apply a forwarding drive to said filter as a result of controlled extrusion of said outlet sealing plug.

Claim 6

Dependent Claim 72 words

A process as claimed in claim 1 wherein the said backing support exits from the filtering passage via a said outlet port and is keyed to the sealing plug therein and wherein the hydrostatic pressure of the substance within said passage acting upon the sealing plug within the outlet port is utilized to apply a forwarding drive to said backing support as a result of controlled extrusion of said outlet sealing plug.

Claim 7

Dependent Claim 202 words

A process for filtering a substance flowing into a chamber comprising the steps of introducing a filter by passing it through inlet and outlet ports flanking said chamber so that a part of the filter extends across the chamber so as to be subject on opposed surfaces thereof to the pressure of substance to be filtered, the filter having an interior permeable to the substance to be filtered, forcing the substance through the filter part in the passage and into the permeable interior thereof, extracting the filtered substance from the said interior of the filter, providing a flowable sealing substance in said inlet and outlet ports, maintaining temperature conditions at said inlet and outlet ports resulting in the formation therein of sealing plugs of said flowable sealing substance of adequate rigidity to prevent substantial leakage from said ports of the substance being filtered, moving the filter when desired to introduce another part thereof into said chamber under conditions providing for maintenance of the sealing plugs, and arranging that forces developed as the result of hydrostatic pressure differentials betweeN the interior and exterior of the filter and acting upon the filter produce substantially no net forces tending to restrict movement of the filter.

Claim 8

Dependent Claim 202 words

A process for filtering a substance flowing into a chamber comprising the steps of introducing a filter by passing it through inlet and outlet ports flanking said chamber so that a part of the filter extends across the chamber so as to be subject on opposed surfaces thereof to the pressure of substance to be filtered, the filter having an interior permeable to the substance to be filtered, forcing the substance through the filter part in the passage and into the permeable interior thereof, extracting the filtered substance from the said interior of the filter, providing a flowable sealing substance in said inlet and outlet ports, maintaining temperature conditions at said inlet and outlet ports resulting in the formation therein of sealing plugs of said flowable sealing substance of adequate rigidity to prevent substantial leakage from said ports of the substance being filtered, moving the filter when desired to introduce another part thereof into said chamber under conditions providing for maintenance of the sealing plugs, and arranging that forces developed as the result of hydrostatic pressure differentials betweeN the interior and exterior of the filter and acting upon the filter produce substantially no net forces tending to restrict movement of the filter.

Claim 9

Dependent Claim 28 words

A process as claimed in claim 6 wherein the said filter is formed as a composite structure comprising at least one filter proper and a backing support therefor.

Claim 10

Dependent Claim 18 words

A process as claimed in claim 6 wherein the said filter is formed as an integral self-supporting structure.

Claim 11

Dependent Claim 33 words

A process as claimed in claim 6 including impregnating the interior of said filter prior to entry thereof into said chamber with a substance to be introduced into the substance to be filtered.

Claim 12

Dependent Claim 19 words

A process as claimed in claim 9 wherein the impregnant substance comprises the same substance as that being filtered.

Claim 13

Dependent Claim 19 words

A process as claimed in claim 10 including impregnating the filter interior by bleeding substance from the said chamber.

Claim 14

Dependent Claim 22 words

A process as claimed in claim 9 wherein the impregnant substance is an additive substance for introduction into the substance being filtered.

Claim 15

Dependent Claim 28 words

A process as claimed in claim 6 wherein the movement of the filter is controlled at least in part as the result of a mechanical force applied thereto.

Claim 16

Dependent Claim 60 words

A process as claimed in claim 6 wherein the said filter is keyed to the sealing plug in the outlet port and the hydrostatic pressure of the substance being filtered acting upon the sealing plug within the outlet port is utilized to apply a forwarding drive to said filter as a result of controlled extrusion of said outlet sealing plug.

Claim 17

Dependent Claim 162 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, inlet and outlet ports flanking the passage through which a filter is passed and can be moved to introduce different parts of the filter across the passage, means for providing temperature conditions at the ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to permit movement of said filter through said ports without substantial leakage of substance being filtered from the ports, and a movable backing support supporting the filter across the passage and serving as a movable bearing for the filter, the arrangement of the backing support being forcewise symmetrical in that forces applied to the backing support as the result of a hydrostatic pressure differential across the filter urging the filter against the backing support are at least substantially equalized by oppositely directed forces likewise applied to the backing support.

Claim 18

Dependent Claim 162 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, inlet and outlet ports flanking the passage through which a filter is passed and can be moved to introduce different parts of the filter across the passage, means for providing temperature conditions at the ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to permit movement of said filter through said ports without substantial leakage of substance being filtered from the ports, and a movable backing support supporting the filter across the passage and serving as a movable bearing for the filter, the arrangement of the backing support being forcewise symmetrical in that forces applied to the backing support as the result of a hydrostatic pressure differential across the filter urging the filter against the backing support are at least substantially equalized by oppositely directed forces likewise applied to the backing support.

Claim 19

Dependent Claim 159 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and inlet and outlet ports through which at least one filter can be passed and moved to introduce different filter parts across the passage, said ports being adapted for the provision thereat, in use, of such temperature conditions as to result in the formation within said ports of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage of substance being filtered, and a movable backing support serving as a movable bearing for said at least one filter within the passage, the said at least one filter being so arranged relative to the backing support and the arrangement of the backing support being such that forces applied to the backing support in use of the device as a result of a hydrostatic pressure differential across the said at least one filter tend to cancel.

Claim 20

Dependent Claim 159 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and inlet and outlet ports through which at least one filter can be passed and moved to introduce different filter parts across the passage, said ports being adapted for the provision thereat, in use, of such temperature conditions as to result in the formation within said ports of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage of substance being filtered, and a movable backing support serving as a movable bearing for said at least one filter within the passage, the said at least one filter being so arranged relative to the backing support and the arrangement of the backing support being such that forces applied to the backing support in use of the device as a result of a hydrostatic pressure differential across the said at least one filter tend to cancel.

Claim 21

Dependent Claim 66 words

A filtering device as claimed in claim 16 wherein said at least one filter is in the form of a single band, said movable backing support is in the form of a generally cylindrical member rotatable about an axis transverse to the direction of filter movement and apertured for extractive flow of filtered substance and said single filter band is looped around said generally cylindrical member.

Claim 22

Dependent Claim 28 words

A filtering device as claimed in claim 17 wherein said single filter band is operative for filtering throughout substantially the entirE surface area of said generally cylindrical member.

Claim 23

Dependent Claim 24 words

A filtering device as claimed in claim 18 including rollers located for guilding said single filter band to loop around said generally cylindrical member.

Claim 24

Dependent Claim 60 words

A filtering device as claimed in claim 17 further including means for co-operation with said generally cylindrical member for establishing at least two filtering stations corresponding to areas of the said generally cylindrical member whereat, in use of the device, filtering can take place, the filtering stations being so arranged that hydrostatic forces applied thereto in use tend to equilibrate.

Claim 25

Dependent Claim 59 words

A filtering device as claimed in claim 20 wherein said generally cylindrical member comprises a cylindrical drum having apertures in the curved surface thereof communicating with at least one extraction passage, and said means for establishing filtering stations comprises means for masking the apertures in the said curved surface other than in certain regions thereof constituting said filtering stations.

Claim 26

Dependent Claim 57 words

A filtering device as claimed in claim 20 wherein said generally cylindrical member has formed therein a plurality of extraction channels each in communication with at least one said aperture in the backing support surface, and said means for establishing filtering stations comprises valve means operative selectively to block flow of filtered substance through said extraction channels.

Claim 27

Dependent Claim 94 words

A filtering device as claimed in claim 16 including at least two said filters associated with a single backing support arrangement, each said filter being associated with and operative throughout at least one filtering station established in the supporting surface of the backing support, the said filtering stations being so arranged relative to the backing support arrangement that forces applied to the backing support arrangement at the filtering stations, as the result of hydrostatic pressure differentials across the filters at the filtering stations urging the filters against the backing support arrangement, tend to cancel.

Claim 28

Dependent Claim 55 words

A filtering device as claimed in claim 23 wherein said at least two filters are each in the form of a band, and said movable backing support is in the form of a generally cylindrical member rotatable about an axis transverse to the direction of filter movement and apertured for extractive flow of filtered substance.

Claim 29

Dependent Claim 59 words

A filtering device as claimed in claim 24 wherein said generally cylindrical member comprises a cylindrical drum having apertures in the curved surface thereof communicating with at least one extraction passage, and said means for establishing filtering stations comprises means for masking the said apertures in the curved surface other than in certain regions thereof constituting said filtering stations.

Claim 30

Dependent Claim 57 words

A filtering device as claimed in claim 24 wherein said generally cylindrical member has formed therein a plurality of extraction channels each in communication with at least one said aperture in the backing support surface, and said means for establishing filtering stations comprises valve means operative selectively to block flow of filtered substance through said extraction channels.

Claim 31

Dependent Claim 72 words

A filtering device as claimed in claim 23 wherein there are provided two filters and said backing support comprises two cylindrical backing drums, one drum for each said filter, rotatable about axes transverse to the direction of movement of said filters and arranged with their axes of rotation parallel and their curved filtersupporting surfaces in contact, the two drums rotating in use both at the same peripheral speed but in opposite directions.

Claim 32

Dependent Claim 24 words

A filtering device as claimed in claim 27 including a single said inlet port and a single said outlet port for said two filters.

Claim 33

Dependent Claim 55 words

A filtering device as claimed in claim 16 wherein the said outlet port presents a greater effective area to said passage than said inlet port whereby the hydrostatic pressure of the substance being filtered produces a net forCe tending to extrude the sealing plug in the outlet port and thereby tending to forward the filter.

Claim 34

Dependent Claim 79 words

A filtering device as claimed in claim 16 including means for cooperation with the backing support for establishing filtering stations corresponding to areas of the backing support only whereat in use of the device filtering can take place, the filtering stations being so arranged relative to the backing support that forces applied to the backing support at the filtering stations, as the result of hydrostatic pressure differentials developed across the filters at the filtering stations, at least substantially equilibrate.

Claim 35

Dependent Claim 61 words

A filtering device as claimed in claim 30 wherein said means for establishing said filtering stations includes means to establish temperature conditions in areas of the backing support, other than said areas only whereat in use of the device filtering can take place, such that in such areas the substance being filtered becomes too viscous for passage through the filter band.

Claim 36

Dependent Claim 44 words

A filtering device as claimed in claim 31 wherein heating means are provided in the regions of said filtering stations, and the regions next adjacent said filtering stations are adapted for cooling, heat insulation means being provided between the thus-heated and the thus-cooled regions.

Claim 37

Dependent Claim 115 words

A filtering device as claimed in claim 30 wherein said movable backing support comprises a cylindrical drum mounted for rotation about an axis transverse to the direction of filter movement, the circumferential curved surface of said drum constituting the filter supporting surface thereof, apertures are provided in the supporting surface of the backing support throughout a central portion of the circumferential curved surface of said drum between two end portions thereof, a plurality of extraction channels are formed in said drum, each said extraction channel communicating with at least one said aperture, and said means for establishing said filtering stations comprises valve means operative selectively to block flow of filtered substance through said extraction channels.

Claim 38

Dependent Claim 85 words

A filtering device as claimed in claim 33 wherein said valve means is constituted by cooperating apertures formed in a surface of said cylindrical drum and in a closely-contacting surface of a non-rotating member, said apertures in said surface of said cylindrical drum communicating with said extraction channels and said apertures in said surface of said non-rotating member communicating with an outlet for filtered substance, said valve means being open when said drum apertures are in registry with said member apertures and otherwise being closed.

Claim 39

Dependent Claim 27 words

A filtering device as claimed in claim 34 wherein said drum is mounted for rotation on a shaft and said member is non-rotatable relative to said shaft.

Claim 40

Dependent Claim 58 words

A filtering device as claimed in claim 35 wherein said member comprises a disc-shaped member, said drum has a recess in an axial end thereof, said disc-shaped member being received in said recess, and said cooperating surfaces defining said valve means are constituted by the edge surface of said disc-shaped member and an adjacent surface of said recess.

Claim 41

Dependent Claim 26 words

A filtering device as claimed in claim 36 including sealing means preventing incursion of unfiltered substance into the junction of said disc-shaped member and said drum.

Claim 42

Dependent Claim 21 words

A filtering device as claimed in claim 37 wherein said sealing means comprises a diaphragm seal adapted to overlie said junction.

Claim 43

Dependent Claim 79 words

A filtering device as claimed in claim 16 wherein said movable backing support comprises a plurality of generally cylindrical members mounted in a sequential array and each rotatable about an axis transverse to the direction of filter movement, said array of generally cylindrical members serving on one side thereof as a movable bearing for one band and on the other side thereof as a movable bearing for a second band, at least one of said bands comprising a filter.

Claim 44

Dependent Claim 83 words

A filtering device as claimed in claim 16 wherein Said movable backing support comprises a hollow cylindrical drum rotatably received within a recess formed within the said body of the device, said recess having at least two arcuate enlargements defining filtering chambers, each of said filtering chambers having an inlet for substance to be filtered an inlet port for the respective filter and an outlet port, said inlet and outlet ports being formed in the body of the device around said filtering chambers.

Claim 45

Dependent Claim 68 words

A filtering device as claimed in claim 40 wherein said outlet ports are of greater cross-sectional area than said inlet ports whereby the hydrostatic pressure of the substance being filtered produces net forces tending to extrude the sealing plugs in the outlet ports, the arrangement being such that said net forces apply to the backing support a resultant torque for rotation thereof in the direction of filter forwarding.

Claim 46

Dependent Claim 95 words

A filtering device as claimed in claim 16 wherein said backing support is in the form of a hollow cylindrical drum having a hollow inner hub joined thereto by means of a web, extraction channels in said web communicating between apertures in said drum and said hollow inner hub, and means are provided in parts of the body of the device closely adjacent said web for providing such temperature conditions as to result in the formation between said body part and the said web of seals of sufficiently solidified substance preventing substantial leakage of substance.

Claim 47

Dependent Claim 253 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and slotted inlet and outlet ports flanking said passage through which a filter in the form of a band is passed and can be moved to introduce different filter parts across said passage, means for maintaining temperature conditions at said ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to permit movement of said filter through said ports without substantial leakage of substance being filtered, the device further including a movable backing support in the form of a generally cylindrical member mounted for rotation about an axis transverse to the direction of filter movement and serving as a movable bearing for the filter, said member having openings in its circumferential curved surface in fluid flow communication with at least one extraction passage formed within the member, said openings serving in use for admitting filtered substance which passes through the filter supported upon said surface into said at least one extraction passage, and the filter being looped around the said member so as to be operative throughout substantially the entire curved surface area of the said member whereby forces applied to the said member in use of the device as the result of a hydrostatic pressure differential across the filter urging the filter against the member produce at least substantially no net force tending to restrict the ease of rotation of the said member.

Claim 48

Dependent Claim 253 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and slotted inlet and outlet ports flanking said passage through which a filter in the form of a band is passed and can be moved to introduce different filter parts across said passage, means for maintaining temperature conditions at said ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to permit movement of said filter through said ports without substantial leakage of substance being filtered, the device further including a movable backing support in the form of a generally cylindrical member mounted for rotation about an axis transverse to the direction of filter movement and serving as a movable bearing for the filter, said member having openings in its circumferential curved surface in fluid flow communication with at least one extraction passage formed within the member, said openings serving in use for admitting filtered substance which passes through the filter supported upon said surface into said at least one extraction passage, and the filter being looped around the said member so as to be operative throughout substantially the entire curved surface area of the said member whereby forces applied to the said member in use of the device as the result of a hydrostatic pressure differential across the filter urging the filter against the member produce at least substantially no net force tending to restrict the ease of rotation of the said member.

Claim 49

Dependent Claim 300 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and slotted inlet and outlet ports flanking said passage through which a filter in the form of a band is passed and can be moved to introduce different filter parts across said passage, means for maintaining temperature conditions at said ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to permit movement of said filter through said ports without substantial leakage of substance being filtered, the device further including a movable backing support in the form of a generally cylindrical member mounted for rotation about an axis transverse to the direction of filter movement and serving as a movable bearing for the filter, said member having openings in its circumferential curved surface in fluid flow communication with at least one extraction passage formed within the member, said openings serving in use for admittinG filtered substance which passes through the filter supported upon said surface into said at least one extraction passage, and means cooperating with the backing support to establish at least two filtering stations corresponding to areas of the backing support only whereat in use of the device filtering can take place, the filter being looped around the said member so as to be operative at said at least two filtering stations and the filtering stations being so arranged relative to the backing support that forces developed thereat upon the backing support as the result of a hydrostatic pressure differential across the filter in the region of each filtering station urging the filter against the backing support tend to cancel thereby producing at least substantially no net force tending to restrict the ease of movement of the backing support.

Claim 50

Dependent Claim 300 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and slotted inlet and outlet ports flanking said passage through which a filter in the form of a band is passed and can be moved to introduce different filter parts across said passage, means for maintaining temperature conditions at said ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to permit movement of said filter through said ports without substantial leakage of substance being filtered, the device further including a movable backing support in the form of a generally cylindrical member mounted for rotation about an axis transverse to the direction of filter movement and serving as a movable bearing for the filter, said member having openings in its circumferential curved surface in fluid flow communication with at least one extraction passage formed within the member, said openings serving in use for admittinG filtered substance which passes through the filter supported upon said surface into said at least one extraction passage, and means cooperating with the backing support to establish at least two filtering stations corresponding to areas of the backing support only whereat in use of the device filtering can take place, the filter being looped around the said member so as to be operative at said at least two filtering stations and the filtering stations being so arranged relative to the backing support that forces developed thereat upon the backing support as the result of a hydrostatic pressure differential across the filter in the region of each filtering station urging the filter against the backing support tend to cancel thereby producing at least substantially no net force tending to restrict the ease of movement of the backing support.

Claim 51

Dependent Claim 240 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow and slotted inlet and outlet ports flanking said passage through which at least two filters each in the form of a band are passed and can be moved to introduce different filter parts across the passage, said ports being adapted for the provision thereat in use of such temperature conditions as to result in the formation therein of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage of substance being filtered, a movable backing support supporting said at least two filters across the passage and serving as movable bearings for the filters, the backing support being adapted to receive filtered substance passing through the filters and being in fluid flow communication with at least one extraction channel for filtered substance, and means for cooperation with the backing support for establishing filtering stations corresponding to areas of the backing support only whereat in use of the device filtering can take place, each of said at least two filters being associated with and operative throughout at least one said filtering station and the filtering stations being so arranged relative to the backing support that forces applied to the backing support as a result of hydrostatic pressure differentials developed across the filters at the filtering stations urging the filters against the backing support at least substantially equilibrate.

Claim 52

Dependent Claim 240 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow and slotted inlet and outlet ports flanking said passage through which at least two filters each in the form of a band are passed and can be moved to introduce different filter parts across the passage, said ports being adapted for the provision thereat in use of such temperature conditions as to result in the formation therein of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage of substance being filtered, a movable backing support supporting said at least two filters across the passage and serving as movable bearings for the filters, the backing support being adapted to receive filtered substance passing through the filters and being in fluid flow communication with at least one extraction channel for filtered substance, and means for cooperation with the backing support for establishing filtering stations corresponding to areas of the backing support only whereat in use of the device filtering can take place, each of said at least two filters being associated with and operative throughout at least one said filtering station and the filtering stations being so arranged relative to the backing support that forces applied to the backing support as a result of hydrostatic pressure differentials developed across the filters at the filtering stations urging the filters against the backing support at least substantially equilibrate.

Claim 53

Dependent Claim 63 words

A filtering device as claimed in claim 45 wherein said movable backing support comprises a cylindrical drum having extraction apertures for filtered substance in the circumferential curved surface thereof, and said means for establishing filtering stations comprises means for masking the apertures in the said circumferential curved surface of the said cylindrical drum other than in certain regions thereof constituting said filtering stations.

Claim 54

Dependent Claim 79 words

A filtering device as claimed in claim 45 wherein said movable backing support comprises a cylindrical drum having extraction apertures for filtered substance in the circumferential curved surface thereof, and there are provided a plurality of said extraction channels each in communication with at least one said aperture in a different area of the backing support surface, and said means for establishing filtering stations comprises valve means operative selectively to block flow of filtered substance through said extraction channels.

Claim 55

Dependent Claim 115 words

A filtering device as claimed in claim 45 wherein said movable backing support comprises a cylindrical drum mounted for rotation about an axis transverse to the direction of filter movement, the circumferential curved surface of said drum constituting the filter supporting surface thereof, a plurality of apertures for extraction of filtered substance are formed in a central portion of the circumferential curved surface of said drum between two end portions thereof, a plurality of extraction channels are formed in said drum, each said extraction channel communicating with at least one said aperture, and said means for establishing said filtering statioNs comprises valve means operative selectively to block flow of filtered substance through said extraction channels.

Claim 56

Dependent Claim 45 words

A filtering device as claimed in claim 48 wherein said valve means comprises a spring-loaded valve member in each said extraction channel and cam means selectively operating the said spring-loaded valve members of said plurality of extraction channels as said cylindrical drum rotates in use.

Claim 57

Dependent Claim 85 words

A filtering device as claimed in claim 48 wherein said valve means is constituted by cooperating apertures formed in a surface of said cylindrical drum and in a closely-contacting surface of a non-rotating member, said apertures in said surface of said cylindrical drum communicating with said extraction channels and said apertures in said surface of said non-rotating member communicating with an outlet for filtered substance, said valve means being open when said drum apertures are in registry with said member apertures and otherwise being closed.

Claim 58

Dependent Claim 75 words

A filtering device as claimed in claim 50 wherein said drum is mounted for rotation on a shaft, said member is non-rotatably keyed to said shaft, said member comprises a disc-shaped member, said drum has a recess in an axial and thereof, said disc-shaped member being received in said recess, and said cooperating surfaces defining said valve means are constituted by the edge surface of said disc-shaped member and an adjacent surface of said recess.

Claim 59

Dependent Claim 31 words

A filtering device as claimed in claim 51 including sealing means preventing incursion of unfiltered substance into the outlet by way of the junction of said disc-shaped member and said drum.

Claim 60

Dependent Claim 21 words

A filtering device as claimed in claim 52 wherein said sealing means comprises a diaphragm seal adapted to overlie said junction.

Claim 61

Dependent Claim 66 words

A filtering device as claimed in claim 45 wherein there are provided two said filters and said backing support comprises two cylindrical backing drums, one drum serving as movable bearing for each said filter, said drums being arranged with their axes of rotation parallel and their curved surfaces in contact, the two drums rotating, in use, both at the same peripheral speed but in opposite directions.

Claim 62

Dependent Claim 46 words

A filtering device as claimed in claim 54 including mounting means for said two backing drums, said mounting means enabling a degree of movement of said backing drums in a direction towards and away from each other and including spring means urging said backing drums together.

Claim 63

Dependent Claim 72 words

A filtering device as claimed in claim 45 wherein said movable backing support comprises a plurality of generally cylindrical members mounted in a sequential array and each rotatable about an axis transverse to the direction of filter movement, said array of generally cylindrical members serving on one side thereof as a movable bearing for one filter band and on the other side thereof as a movable bearing for a second filter band.

Claim 64

Dependent Claim 61 words

A filtering device as claimed in claim 45 wherein said means for establishing said filtering stations includes means to establish temperature conditions in areas of the backing support, other than said areas only whereat in use of the device filtering can take place, such that in such areas the substance being filtered becomes too viscous for passage through the filter band.

Claim 65

Dependent Claim 98 words

A filtering device as claimed in claim 45 wherein said movable backing support comprises a hollow cylindrical drum rotatably received within a recess formed within the said body of the device, said recess having at least two arcuate enlargements defining filtering chambers, one said filtering chamber being provided for each of said at least two filters, each of said filtering chambers having an inlet for substance to be filtered and an inlet port and an outlet port for the respective filter, said inlet and outlet ports being formed in the body of the device around said filtering chambers.

Claim 66

Dependent Claim 68 words

A filtering device as claimed in claim 58 wherein said outlet ports are of greater cross-sectional area than said inlet ports whereBy the hydrostatic pressure of the substance being filtered produces net forces tending to extrude the sealing plugs in the outlet ports, the arrangement being such that said net forces apply to the backing support a resultant torque for rotation thereof in the direction of filter forwarding.

Claim 67

Dependent Claim 86 words

A filtering device as claimed in claim 58 wherein said hollow cylindrical drum has hollow inner hub joined thereto by means of a web, extraction channels in said web communicating between apertures in said drum and said hollow inner hub, and means are provided in parts of the body of the device closely adjacent said web for providing such temperature conditions as to result in the formation between said body parts and the said web of seals of sufficiently solidified substance preventing substantial leakage of substance.

Claim 68

Dependent Claim 64 words

A filtering device as claimed in claim 45 wherein the said inlet and outlet ports are of different cross-sectional area whereby the hydrostatic pressure of the substance being filtered produces a net force tending to extrude the sealing plug in the outlet port, the arrangement being such that said net force applies to the filters a forwarding drive in the direction of filter movement.

Claim 69

Dependent Claim 48 words

A filtering device as claimed in claim 45 wherein said at least two filters are each in the form of a band comprising a plurality of successive filtering elements, the arrangement being such that said filtering elements locate successively with said filtering stations as said filters are moved.

Claim 70

Dependent Claim 279 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and inlet and outlet ports flanking said passage through which at least one filter in the form of a succession of individual filter elements is passed so as to extend across said passage and can be moved to introduce different filter elements into operative condition at least two at a time, means for maintaining temperature conditions at said ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage through said ports of substance being filtered, a movable backing support in the form of a generally cylindrical member mounted for rotation about an axis transverse to the direction of filter movement and serving as a movable bearing for said at least one filter, said member having openings in its circumferential curved surface adaped for location with said filter elements and in fluid flow communication with at least one extraction passage formed within the member, said openings serving in use for admitting filtered substance which passes through the at least two operative filter elements supported upon said surface into said at least one extraction passage, and means for preventing extraction of substance via openings not located with the at least two operative filter elements, the said at least one filter being so arranged relative to the backing support and the arrangement of the backing support being such that forces applied to the backing support in use of the device as the result of hydrostatic pressure differentials across the said at least two operative filter elements tend to cancel.

Claim 71

Dependent Claim 279 words

A filtering device including a body defining a passage through which a substance to be filtered can be caused to flow, and inlet and outlet ports flanking said passage through which at least one filter in the form of a succession of individual filter elements is passed so as to extend across said passage and can be moved to introduce different filter elements into operative condition at least two at a time, means for maintaining temperature conditions at said ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage through said ports of substance being filtered, a movable backing support in the form of a generally cylindrical member mounted for rotation about an axis transverse to the direction of filter movement and serving as a movable bearing for said at least one filter, said member having openings in its circumferential curved surface adaped for location with said filter elements and in fluid flow communication with at least one extraction passage formed within the member, said openings serving in use for admitting filtered substance which passes through the at least two operative filter elements supported upon said surface into said at least one extraction passage, and means for preventing extraction of substance via openings not located with the at least two operative filter elements, the said at least one filter being so arranged relative to the backing support and the arrangement of the backing support being such that forces applied to the backing support in use of the device as the result of hydrostatic pressure differentials across the said at least two operative filter elements tend to cancel.

Claim 72

Dependent Claim 96 words

A filtering device as claimed in claim 63 including means cooperating with the backing support to establish at least two filtering stations corresponding to areas of the backing support only whereat in use of the device filtering can take place, the filtering stations being so arranged relative to the backing support that forces applied to the backing support at the filtering stations, as the result of hydrostatic pressure differentials developed across the filter elements at the filtering stations, at least substantially equilibrate, and means to ensure registry of said operative filter elements with said filtering stations.

Claim 73

Dependent Claim 32 words

A filtering device as claimed in claim 64 wherein the surface of said generally cylindrical member is formed with portions complementary to the shapE of and adapted to receive the filter elements.

Claim 74

Dependent Claim 35 words

A filtering device as claimed in claim 64 wherein two such filters are associated with a single said generally cylindrical backing support, each said filter being operative at at least one individually assigned filtering station.

Claim 75

Dependent Claim 25 words

A filtering device as claimed in claim 63 wherein said succession of filter elements constituting a said filter are linked together in a chain construction.

Claim 76

Dependent Claim 23 words

A filtering device as claimed in claim 63 wherein said succession of filter elements constituting a said filter are separate from one another.

Claim 77

Dependent Claim 22 words

A filtering device as claimed in claim 68 including drive means operative to push said separate filter elements successively into the device.

Claim 78

Dependent Claim 189 words

A filtering device including a body defining a chamber into which a substance to be filtered can be caused to flow, inlet and outlet ports flanking the chamber through which a filter structure is introduced into the chamber so as, in use of the device, to be subject on opposed surfaces thereof to the pressure of substance to be filtered, said filter structure being movable to introduce different filter parts into the chamber, means for providing temperature conditions at the ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage of substance being filtered from the ports, said filter structure having an interior adapted and arranged to receive only substance filtering through said filter structure and to permit the flow of filtered substance within the said interior and between said opposed surfaces for extraction thereof from the filtering device, at least one outlet for filtered substance in fluid flow communication with said interior of the filter structure and means preventing flow of substance to be filtered directly into said at least one outlet from the said chamber.

Claim 79

Dependent Claim 189 words

A filtering device including a body defining a chamber into which a substance to be filtered can be caused to flow, inlet and outlet ports flanking the chamber through which a filter structure is introduced into the chamber so as, in use of the device, to be subject on opposed surfaces thereof to the pressure of substance to be filtered, said filter structure being movable to introduce different filter parts into the chamber, means for providing temperature conditions at the ports for the formation therein, in use, of sealing plugs of a flowable sealing substance of adequate rigidity to prevent substantial leakage of substance being filtered from the ports, said filter structure having an interior adapted and arranged to receive only substance filtering through said filter structure and to permit the flow of filtered substance within the said interior and between said opposed surfaces for extraction thereof from the filtering device, at least one outlet for filtered substance in fluid flow communication with said interior of the filter structure and means preventing flow of substance to be filtered directly into said at least one outlet from the said chamber.

Claim 80

Dependent Claim 33 words

A filtering device as claimed in claim 70 wherein said filter structure comprises at least one filter proper and a backing support therefor, aaid filter structure interior being constituted by said backing support.

Claim 81

Dependent Claim 57 words

A filtering device as claimed in claim 71 wherein said filter structure comprises two bands sandwiching therebetween said backing support, at least one of said bands comprising said at least one filter proper, the arrangement of said chamber being such that both said two bands are subject in use to the pressure of substance to be filtered.

Claim 82

Dependent Claim 53 words

A filtering device as claimed in claim 70 wherein said filter structure is adapted for edgewise extraction of filtered substance permeating into the said interior thereof, edges of the said filter structure being sealed against internal walls of said chamber, and outlets for filtered substance in said internal walls communicating with said edges.

Claim 83

Dependent Claim 37 words

A filtering device as claimed in claim 73 wherein seals are provided preventing flow of substance to be filtered directly into said outlets, said seals comprising sealing strips arranged along the edges of the said filter structure.

Claim 84

Dependent Claim 45 words

A filtering device as claimed in claim 72 wherein said backing support comprises a corrugated metal band the corrugations of which extend substantially transversely to the length of the band, and the said two bands are separated by the corrugations of said corrugated metal band.

Claim 85

Dependent Claim 82 words

A filtering device as claimed in claim 70 wherein said filter structure is adapted for edgewise extraction of filtered substance permeating into the interior thereof, said filter structure being supported at edges thereof within the said chamber by means of rod-shaped members which extend across the said chamber spaced from the walls thereof, said rod-shaped members having formed therein extraction passages in fluid flow communication with the edges of said composite structure for extractive flow of filtered substance from the interior thereof.

Claim 86

Dependent Claim 90 words

A filtering device as claimed in claim 76 wherein each of said rod-shaped members is Formed in two longitudinal parts which come together to define in said member a recessed seat for the edge of said filter structure, a longitudinal passage for extraction of filtered substance from the device, apertures providing communication between said recessed seat and said longitudinal passage for flow of filtered substance from the interior of the filter structure into said longitudinal passage, and a seat for a sealing strip to seal said two longitudinal parts together.

Claim 87

Dependent Claim 45 words

A filtering device as claimed in claim 76 wherein said rod-shaped members are each formed with a recessed seat to receive an edge of the said filter structure, apertures providing communication between said recessed seat and a longitudinal extraction passage formed within said rod-shaped member.

Claim 88

Dependent Claim 36 words

A filtering device as claimed in claim 70 wherein said filter structure comprises a succession of discrete filter elements each having an interior and each adapted for extractive flow of filtered substance from said interior thereof.

Claim 89

Dependent Claim 19 words

A filtering device as claimed in claim 70 wherein said backing support comprises a plurality of transverse separator slats.

Claim 90

Dependent Claim 50 words

A filtering device as claimed in claim 80 wherein said transverse separator slats are each comprised by a permeable tubular member permitting filtered substance flow through at least one surface thereof and into at least one internal flow passage formed therein and adapted to communicate with the filtering device outlet.

Claim 91

Dependent Claim 29 words

A filtering device as claimed in claim 80 wherein said transverse separator slats are each comprised by hollow elements providing flat filter-supporting surfaces perforated for filtered substance flow therethrough.

Claim 92

Dependent Claim 21 words

A filtering device as claimed in claim 82 wherein said filters comprise individual filter sections carried upon said flat filter-supporting surfaces.

Claim 93

Dependent Claim 30 words

A filtering device as claimed in claim 70 wherein said filter structure comprises a plurality of discrete filter elements contained in apertures formed in a pair of continuous metal tapes.

Claim 94

Dependent Claim 50 words

A filtering device as claimed in claim 71 wherein said filter structure comprises a folded sheet of sintered metal constituting said filter proper supported by an inner permeable backing support and arranged for sliding movement over a guide member provided within the filtering passage and having extraction channels formed therein.

Claim 95

Dependent Claim 26 words

A filtering device as claimed in claim 70 wherein said filter structure is constructed to restrict flow of filtered substance in the direction of filter movement.

Claim 96

Dependent Claim 33 words

A filtering device as claimed in claim 70 including means operative to impregnate the interior of the filter structure with substance of the type to be filtered before entry thereof into said chamber.

Claim 97

Dependent Claim 30 words

A filtering device as claimed in claim 87 including an impregnation station and a feed passage provided in the body of the device to bleed substance to said impregnation station.

Claim 98

Dependent Claim 54 words

A filtering device as claimed in claim 87 including means operative to control the supply of impregnant, said means including means for sensing the extent of penetration of impregnant into the interior of the filter structure in in a direction opposite to the direction of movement of the filter structure into the inlet port.

Claim 99

Dependent Claim 29 words

A filtering device as claimed in claim 88 wherein said impregnation station is formed integrally with the inlet port through which said filter structure is admitted to the device.

Claim 100

Dependent Claim 45 words

A filtering device as claimed in claim 90 wherein said impregnation station comprises a zone of said inlet port provided with heating means and intermediate and thermally insulated from two zones provided with cooling means, said feed passage connecting with said inlet port intermediate zone.

Claim 101

Dependent Claim 53 words

A filtering device as claimed in claim 91 wherein said cooled zones are arranged to be selectively heated or cooled, and a further cooled zone is provided in the inlet port, said further cooled zone being located to be the last zone traversEd by the filter structure during entry thereof into the device.

Claim 102

Dependent Claim 202 words

A filtering device including a body defining a chamber into which a substance to be filtered can be caused to flow, slotted inlet and outlet ports flanking said chamber through which two filters each in the form of a band can be passed and moved to introduce different parts of said filters across the chamber, inlet and outlet ports flanking said chamber for the introduction into and extraction from the chamber of a plurality of filter support elements, said two filter bands and said filter support elements forming within the chamber a composite filter/backing support structure which is movable through the chamber and has the said filter support elements sandwiched between the filter bands with the filter support elements extending transversely to the length of the filters, said filter support elements being formed to provide a facility for extractive flow of filtered substance in a direction transverse to the flow of substance through the filters during filtering, at least one outlet for filtered substance arranged for extraction of filtered substance permeated into the backing support, and sealing means in said chamber permitting movement of said composite structure whilst preventing flow of substance to be filtered directly into said at least one outlet.

Claim 103

Dependent Claim 202 words

A filtering device including a body defining a chamber into which a substance to be filtered can be caused to flow, slotted inlet and outlet ports flanking said chamber through which two filters each in the form of a band can be passed and moved to introduce different parts of said filters across the chamber, inlet and outlet ports flanking said chamber for the introduction into and extraction from the chamber of a plurality of filter support elements, said two filter bands and said filter support elements forming within the chamber a composite filter/backing support structure which is movable through the chamber and has the said filter support elements sandwiched between the filter bands with the filter support elements extending transversely to the length of the filters, said filter support elements being formed to provide a facility for extractive flow of filtered substance in a direction transverse to the flow of substance through the filters during filtering, at least one outlet for filtered substance arranged for extraction of filtered substance permeated into the backing support, and sealing means in said chamber permitting movement of said composite structure whilst preventing flow of substance to be filtered directly into said at least one outlet.

Claim 104

Dependent Claim 227 words

A filtering device including a body defining a chamber into which a substance to be filtered can be caused to flow, inlet and outlet ports flanking said chamber through which a filter structure is introduced into the chamber so as, in use of the device, to be subject on opposed surfaces thereof to the pressure of substance to be filtered, said filter structure being movable to introduce different filter parts into the chamber, means for providing temperature conditions at said ports resulting in the formation therein, in use, of sealing plugs of a flowable sealing substance, at least one outlet for filtered substance adapted for fluid flow communication with a portion of said filter structure, means sealing said at least one outlet to said portion to prevent direct flow of substance to be filtered into said at least one outlet while permitting movement of said filter structure, said filter structure comprising a composite structure of at least one filter proper and a permeable backing support therefor, said permeable backing support defining in said filter structure an interior adapted and arranged to receive substance filtering through said at least one filter proper and to permit the flow of filtered substance within the said interior and between said opposed surfaces for extraction thereof from the filter device, and said at least one outlet communicating with said permeable backing support.

Claim 105

Dependent Claim 227 words

A filtering device including a body defining a chamber into which a substance to be filtered can be caused to flow, inlet and outlet ports flanking said chamber through which a filter structure is introduced into the chamber so as, in use of the device, to be subject on opposed surfaces thereof to the pressure of substance to be filtered, said filter structure being movable to introduce different filter parts into the chamber, means for providing temperature conditions at said ports resulting in the formation therein, in use, of sealing plugs of a flowable sealing substance, at least one outlet for filtered substance adapted for fluid flow communication with a portion of said filter structure, means sealing said at least one outlet to said portion to prevent direct flow of substance to be filtered into said at least one outlet while permitting movement of said filter structure, said filter structure comprising a composite structure of at least one filter proper and a permeable backing support therefor, said permeable backing support defining in said filter structure an interior adapted and arranged to receive substance filtering through said at least one filter proper and to permit the flow of filtered substance within the said interior and between said opposed surfaces for extraction thereof from the filter device, and said at least one outlet communicating with said permeable backing support.

Claim 106

Dependent Claim 23 words

A filtering device as claimed in claim 94 wherein the filter proper and the backing support therefor are formed integrally with one another.

Claim 107

Dependent Claim 41 words

A filtering device as claimed in claim 94 wherein said filter structure comprises a permeable backing support sandwiched between two bands at least one of which comprises a filter, extraction of filtered substance taking place from the edges of said sandwich.

Claim 108

Dependent Claim 30 words

A filtering device as claimed in claim 94 wherein the interstices of at least the permeable backing support are impregnated with a substance to be introduced into the filtered substance.

Claim 109

Dependent Claim 23 words

A filtering device as claimed in claim 97 wherein said substance to be introduced includes an additive substance different from the filtered substance.

Claim 110

Dependent Claim 15 words

A filtering device as claimed in claim 94 wherein said backing support comprises sintered metal.

Claim 111

Dependent Claim 33 words

A filtering device as claimed in claim 99 wherein said sintered metal backing support is formed with internal extraction passageways and reinforcing means are provided in said passageways for strengthening the backing support.

Claim 112

Dependent Claim 16 words

A filtering device as claimed in claim 94 wherein said backing support includes helical wire coils.

Claim 113

Dependent Claim 20 words

A filtering device as claimed in Claim 94 wherein said backing support comprises bent or convoluted sheet or strip metal.

Claim 114

Dependent Claim 24 words

A filtering device as claimed in claim 94 wherein said backing support comprises a plurality of discrete spacers secured together to form a band.

Claim 115

Dependent Claim 29 words

A filtering device as claimed in claim 94 wherein said at least one filter proper comprises fine woven wire cloth and said backing support comprises coarse woven wire cloth.

Claim 116

Dependent Claim 56 words

A filtering device as claimed in claim 94 wherein said filter structure comprises a plurality of discrete filtering elements received in the apertures of at least one flexible metal ladder tape, said filtering elements each having an interior adapted to receive substance filtered by the respective element and to permit extractive flow of the filtered substance.

Claim 117

Dependent Claim 16 words

A filtering device as claimed in claim 105 wherein said elements are formed of sintered metal.

Claim 118

Dependent Claim 27 words

A filtering device as claimed in claim 106 wherein said sintered metal elements are each faced with at least one filter element formed of woven wire cloth.

Claim 119

Dependent Claim 71 words

A filtering device as claimed in claim 94 wherein said filter structure comprises a plurality of permeable sintered metal elements each adapted for exposure to substance to be filtered at at least one surface thereof for permeation of substance into the interior of the element, the elements furthermore being formed to provide a facility for extractive flow of filtered substance received within the interior thereof towards said at least one outlet.

Claim 120

Dependent Claim 18 words

A filtering device as claimed in claim 106 wherein said sintered metal elements each have a hollow interior.

Claim 121

Dependent Claim 44 words

A filtering device as claimed in claim 94 wherein said filter structure comprises a plurality of discrete elements each provided with sealing skirts adapted to overlap with like sealing skirts of an abutting like element to prevent substantial flow of substance between abutting elements.

Claim 122

Dependent Claim 34 words

A filtering structure as claimed in claim 108 provided with sealing skirts adapted to overlap with like sealing skirts of an abutting like element to prevent substantial flow of substance between the two elements.

Claim 123

Dependent Claim 47 words

A filtering device as claimed in claim 94 wherein said filter structure includes at least one layer of woven wire cloth and at least one other layer, and means are provided to restrict the flow of filtered substance within said layers in the plane of said layers.

Claim 124

Dependent Claim 126 words

A filtering device as claimed in claim 15 further including means connected to the filtered substance outlet of said device for filtering, for reducing pressure fluctuations in said filtered substance, said means including a fluid-filled enclosure, pressure control means for maintaining constant the pressure of said fluid in said enclosure, temperature control means for maintaining constant the temperature of said fluid in said enclosure, an at least substantially non-resilient volume variable pressure-transfer member within said enclosure, said presssure-transfer member having an exterior subject to the pressure of said fluid in said enclosure and an interior isolated from said exterior and in fluid flow communication with said filtered substance outlet of said device, and an outlet for filtered substance communicating with said interior of said pressure-transfer member.

Claim 125

Dependent Claim 32 words

A combination as claimed in claim 113 wherein said pressure transfer member is arranged to deliver the flow of substance passing through it to said outlet by way of hydrostatic damping means.

Claim 126

Dependent Claim 19 words

A combination as claimed in claim 114 wherein said hydrostatic damping means comprises a capillary contained within said enclosure.

Claim 127

Dependent Claim 38 words

A combination as claimed in claim 115 wherein said capillary is provided with heat exchanger means by virtue of which the temperature of the substance flowing within the capillary is determined to be that of the said enclosure.

Claim 128

Dependent Claim 46 words

A combination as claimed in claim 113 wherein said pressure transfer member is arranged to deliver the flow of substance Passing through it to said outlet by way of heat exchanger means adapted to determine the temperature of said substance to be that of said enclosure.

Claim 129

Dependent Claim 17 words

A combination as claimed in claim 113 wherein said pressure transfer member comprises a flexible tubular member.

Claim 130

Dependent Claim 161 words

A filtering device as claimed in claim 15 further including means connected to the filtered substance outlet of said device for filtering for monitoring the volume of filtered substance supplied thereby, said means including two series-connected non-resilient bellows members each contained in a separate temperature-controlled enclosure filled with a heat-transfer fluid and each having associated therewith a series-connected capillary, the capillary associated with the first said bellows member having an outlet into the second said bellows member and the capillary associated with the second said bellows member communicating with a system output, a pressure chamber communicating with said first enclosure, a spring loaded piston in said pressure chamber movable in dependence upon the pressure therein, a second pressure chamber communicating with said second enclosure, a second spring loaded piston in said second pressure chamber movable in dependence upon the pressure therein, snd means responsive to the differential displacements of said first and second pistons for providing an indication of fluid flow.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-12-23	1978-06-24	1978-12-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-12-23	1982-06-24	1982-12-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-12-23	1986-06-24	1986-12-24	$7700.00	Window Closed / Lapsed

Filtering process and apparatus

Abstract

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