Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
  • B01D35/28—Strainers not provided for elsewhere
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D33/00—Filters with filtering elements which move during the filtering operation
  • B01D33/01—Filters with filtering elements which move during the filtering operation with translationally moving filtering elements, e.g. pistons
  • B01D33/03—Filters with filtering elements which move during the filtering operation with translationally moving filtering elements, e.g. pistons with vibrating filter elements
  • B01D33/0346—Filters with filtering elements which move during the filtering operation with translationally moving filtering elements, e.g. pistons with vibrating filter elements with flat filtering elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D33/00—Filters with filtering elements which move during the filtering operation
  • B01D33/44—Regenerating the filter material in the filter
  • B01D33/46—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element
  • B01D33/461—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element brushes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D33/00—Filters with filtering elements which move during the filtering operation
  • B01D33/70—Filters with filtering elements which move during the filtering operation having feed or discharge devices
  • B01D33/76—Filters with filtering elements which move during the filtering operation having feed or discharge devices for discharging the filter cake, e.g. chutes

Definitions

• the present invention relates to a method and an apparatus for separating bodies (matter) from a liquid, according to the preambles to independent claims 1 and 12.
• body in the preceding paragraph is, herein, employed in its very broadest interpretation to disclose "occur ⁇ rences” (bodies/matter) in the liquid, these being characterised in that they are of a consistency which deviates from that of the liquid.
• Examples - which should not be considered as restrictive as regards, for example, size - of such bodies are splinters, sawdust, chips, grain, powder, plant parts, fibres, lumps (including gelati ⁇ nous such lumps), depositions, floes, fish, fish spawn, fry, algae, particles, oil droplets etc.
• the word body (matter) will also have the above-outlined broad scope of meaning in the following descrip- tio ⁇ and in the appended claims.
• a number of screening apparatuses are known in this art in which a screen grid is placed in a liquid flow .in order to separate-off pollutants and contaminants in the liquid.
• Such apparatuses are provided, in certain physical applications, with vertically reciprocating devices which mechanically move the pollutants deposited on the grid upwards and out of the liquid-and to a receptacle.
• vertically reciprocating devices which mechanically move the pollutants deposited on the grid upwards and out of the liquid-and to a receptacle.
• Such apparatuses suffer from the drawback that they are relatively tall and require mechanically stable frames in order not to jeopardise operational safety and reliability.
• the filters employed in such apparatuses become readily blocked, thus often necessitating regular cleaning.
• This apparatus is primarily intended for use as a separator which, in paper aking, separates off coarser particles and allows smaller particles to pass, for example to allow water and paper fibres to pass, while separating off splinters, sawdust and pro ⁇ jections (column 4, lines 38-40).
• the apertures of the screen mesh are reduced in size in order also to separate-off the fibres (column 5, lines 1-11).
• the fibre mat which is thereby formed migrates, because of the vibrations, along the upper surface of the screen mesh and leaves the apparatus at its upper end (the discharge end). Since large areas of the screen surface remain covered by pollutants during the screening operation, a screen according to the described embodiment suffers from reduced flow capacity, which results in requirements of larger screen surface operative areas with consequentially .increased, costs.
• a further screening apparatus comprising one fixed and one moving grid formed of rods which are placed obliquely in relation to the direction of flow of the water.
• the rods are provided with shoulders, whereby the shoulders of the moving grid shift the gathered pollutants upwardly along the fixed rods at the same time as the moving grid executes a substantially circular movement in order to collect and deposit matter gathered against the screen.
• large areas of the screen surface remain covered by the separated material and, as a consequence, the through-flow area of the apparatus is reduced. In order to attain the desired capacity, relatively large installations of this type are required, with consequentially elevated costs.
• the present invention discloses a technique in which also in large water flow volumes, substantially the entire screen surface is cleaned of collected bodies (matter) during, as a rule, relatively short time intervals and in which the released bodies (matter) are substantially immediately thereafter moved direct towards that region of the screen surface which is located in association with the sur ⁇ face of the liquid.
• the characterising clauses of claims 1 and 12 describe the method and the apparatus according to the present invention for realising the contemplated effect.
• the dependent claims disclose advantageous embodiments of the present invention.
• Fig. 1 is a perspective view of a fundamental apparatus according to the present invention
• Figs. 2a,2b are longitudinal sections through a filter apparatus placed in a bath through which a liquid flows
• Figs. 3a, 3b are longitudinal sections through alternative embodiments of the filter apparatus according to the present invention
• Fig. 3c is a partial section through an alternative embodiment of the discharge section of the filter apparatus
• Fig. 4 is a section taken along the line IV—IV in Figs. 3a or 3b.
• Figs 1-4 illustrate embodiments of the present invention in which a filter 11 is placed in an apparatus 22, for example a channel, or a bath, through which liquid 10 passes from the inflow end 37 of the apparatus and to its outflow end 38.
• the designation bath 22 will gener- ally be used, without restrictive import, for this apparatus.
• the designations inflow end and outflow end, respectively, are also to be considered as blanket terms and, herein, relate to regions upstream of the filter, and regions downstream of the filter, respectively.
• the liquid which is supplied at the inflow end 37 contains bodies (matter) 16 to be removed from the liquid, while the liquid in the region of the outflow end 38 is substantially free of such bodies.
• the liquid passes into the bath 22 by the intermediary of one or more inflows 23.
• the bottom 32 and side walls 33a, b of the bath are specifically disclosed.
• the filter 11 is illustrated in embodiments in which the filter is pivotally journaled about a shaft 20.
• a shaft 20 which is fixedly anchored at the frame 41 ' of the filter 11 and, in its turn, rests in journals 40.
• the filter is ovably journaled in relation to the shaft 20.
• Drive means (not shown) are provided for reciprocally pivoting the filter within adjustable extreme limits.
• the pivotal action is effected by means of the shaft 20, while in others, such action is effected by drive means which act directly on the filter and rotate the filter about the shaft 20, or alternatively about the journals of the shaft.
• the drive means which may be of, for example, hydraulic or electric type, are, furthermore, adjustable for different fixed or varying pivotal speeds. In certain embodiments, the drive means are provided for intermittent pivotal motion of the filter.
• upstream and downstream refer to the flow direction 17 (the major flow direction) along which the liquid follows on its passage through the bath.
• the frame 41 of the filter consists of a transverse frame section 50 located upstream and a transverse frame section 51 located down ⁇ stream, and longitudinal frame sections 52a,b which interconnect the transverse frame sections.
• a filter member 42 for example a filter cloth, a screen grid, a mesh, rods placed in spaced apart relationship, etc, or combinations hereof, is disposed in the frame 41 of the filter.
• the screen apertures and/or mesh gauge of the filter members are adapted to the size of the bodies which are to be separated-off from the liquid.
• the filter member 42 has an upper bounding surface 13 and a lower bounding surface 14 which are located upstream and dov/nstrea of the filter, respectively.
• the filter is, as a rule, disposed in an inclined plane such that the filter most proximal the inflow (upstream) is at a lower position (the lower portion 12 of the filter), and most pro ⁇ ximal the outflow (downstream) is at a higher position (the upper portion 43 of the filter).
• the reference numeral 15 relates to the discharge section of the filter.
• the filter constitutes an upper bounding definition of a space 35.
• the reference numeral 48 is employed for that portion of.this space which is substantially only filled with air, or possibly also to a certain degree with liquid or liquid droplets on their way towards the liquid collected in the bath.
• Figs. l-3a illustrate embodiments of the present invention in which the lower portion 12 of the filter, during the entire movement pattern of the filter, is located at least partially in the liquid and the upper portion 43 of the filter is located above the level of the liquid.
• Fig. 3b illustrates an embodiment of the present invention in which the portion of the filter located most proximal the inflow is located, at least in its uppermost position, above the level of the liquid, i.e. the mean liquid surface level 54, in the region adjacent that part of the filter located most proximal to the outflow.
• the shaft 20, about which the filter pivotally reciprocates, is, as a rule, disposed in immediate conjunction with the downstream trans- verse frame section 51 of the filter.
• a bellow device 31 there is provided, between the frame 41 of the filter and the bath, a bellow device 31 (Figs.
• the lower portion 12 of the filter is, as a rule, disposed to describe a reciprocal movement which is shown, in the figures, as a substantially upward and downward movement in that the filter pivots reciprocally - or in pendular motion - about the shaft 20.
• the angular amplitude of this pendular motion is of the order of magnitude of at most approx. 20° and the mean inclination of the filter in relation to the horizontal plane is at most approx. 30°.
• a brush 21 is provided for realising a supple- mentary displacement of bodies 16a gathered during the separation process to a receptacle device 25a-d.
• this receptacle device is shown in one embodiment in which it is composed of a recep ⁇ tacle shield 25a and a receptacle conduit 25b which discharges into a container 25c.
• An arrow 19 marks the displacement of the particles 16b in the receptacle device.
• Figs. 3b and 3c illustrate one embodi ⁇ ment in which the receptacle device 25d consists of a U-shaped channel 44 which merges into receptacle shield 25d. The channel is provided with a conveyor screw 45 for displacement of the bodies to a receptacle vessel (not shown).
• the brush 21 is shown in one embodiment in which it describes a rotational movement and further includes means (not shown) movable in a direction towards and away from the receptacle device, the brush, on movement from the receptacle device, being located above the upper bounding surface 13 of the filter member 42.
• the brush is substituted by a scraper, or doctor blade.
• Figs. 2-3 there is shown one embodiment of drive means for the pendular motion of the filter.
• the drive means are connected to a rotary shaft 28 which is connected, by the inter ⁇ mediary of a crank lever 27 and a crank shaft 29, to a drive arm 30 which is connected to the filter 11.
• Figs. 3a, 3b and 4 illustrates how one or more defining walls 34, 36 are provided between the filter 11 and the bottom 32 of the bath in order to impede the liquid from being dis ⁇ placed towards the outflow end of the bath when the filter 11 moves downwardly towards the bottom of the bath.
• the defining walls are shown in embodiments in which they form bulkheads 36 upstanding from the bottom of the container or bath, and slightly resiliently yieldable wall portions 34 depending from the filter.
• the purpose of the bulkheads upstanding from the bottom-of the bath is, here, to stabilise the positions of the depending wall portions in the horizontal direction.
• the depending wall portions are, moreover, provided with apertures 26 of a size which is adapted for the requi ⁇ site retardation of the movement of the liquid towards the outflow • portion of the bath in each contemplated field of application.
• Fig. 3b shows one embodiment in which the filter 11 is of substan ⁇ tially planar orientation and in which the filter is, with its portion 12 most proximal the inflow, located above the liquid surface level at least when that portion is in its uppermost position.
• the liquid is supplied in the form of one or more liquid jets 46 which are directed substantially in the plane of the filter and which impinge upon the upper bounding surface 13 of the filter.
• the liquid is supplied in the form of a jet column 46, the column being disposed in the transverse direction of the bath and being substantially horizontal.
• the filter is, in the embodiment illustrated in Fig. 3b, provided on its underside with a substantially vertical wall 47 of a length which entails that the wall always reaches down into the liquid 10a which has passed through the filter.
• the wall connects substantially sealingly with the side walls 33a, b of the bath, whereby the filter and the vertical wall 47 define the space 48 located beneath the filter and containing air - and to a certain degree also liquid - which has just passed the filter member 42.
• Fig. 3b also shows an embodiment in which a spillway overflow 49 regulates the level of liquid in the bath.
• Fig. 3c illustrates in detail an alternative embodiment in which the wall 47 has been substituted by a sealing connection 53 between the filter 41 and the U-shaped channel 44 of the receptacle device.
• this connection is shown in one embodiment in which the connection consists of a flexible diaphragm, for example a rubber sheet.
• this substantially sealing connection may, without departing from the inventive concept as herein disclosed, also be formed, for example, by direct abutment between the filter and the U-shaped channel, the abutment surfaces being here adapted so as to permit, with fully retained sealing function, the movement of the filter in relation to the channel.
• the channel is, furthermore, located so as to entail that the channel, throughout its entire length, reaches down into the liquid 10a.
• the filter describes an upward and downward movement in the liquid, there will be obtained a passage of liquid from one side of the filter to the opposite side, and, in the embodiment illustrated in Figs. 3b and 3c, a pressure change in the space 48 above the surface 54 of the liquid, respectively.
• the bodies are gathered against the filter and, in this instance, also reduce the total open through-flow area of the filter and thereby, to a certain degree, throttle the flow through the filter.
• the bodies gathered against the filter member 42 are released by the - liquid flow which runs from the underface 14 of the filter towards the upper face 13 of the filter and/or by the pressure increase in the space 48.
• the filter is disposed so as, at least during parts of the downwardly directed movement, to avoid allowing liquid to pass through the filter.
• the bodies are moved in a direction towards the discharge portion 15 of the filter, either by a liquid flow in the major flow direction 17 or by the mechanical displacement device 21 which caters for the displacement at least in that part of the filter where the liquid never reaches.
• the speed of movement and mesh gauge of the filter are adapted to the viscosity of the liquid and the size of the bodies, so that, on downward movement of the filter in relation to the liquid, excess pressure arises in the filter surface 14 located downstream of the major flow direction, i.e. the lower bounding surface of the filter. Such is the case irrespective of whether the space 35 adjacent the lower surface 14 includes the space 48 or not.
• the speed of movement, mesh gauge etc. of the filter are selected such that the liquid flow which is led in over the upper surface of the filter generates.a wave motion which' assists in displacing the bodies towards the receptacle device of the filter in that the wave leaves behind.bodies on that region of the filter which, during the greater part of the movement of the filter, is located above the wash of the liquid.
• the through flow of the liquid - and where applicable the wave formation - is amplified in that the defining walls 34, 36 partly hinder the liquid from passing towards the out ⁇ flow end of the bath in conjunction with the downwardly-directed movement of the filter.
• the defining walls also provide the • ⁇ possibility, with the assistance of the space 35, of adaptably governing the through-flow area and thereby the liquid flow in a direction towards the outflow end of the bath in conjunction with the downwardly directed movement of the filter.
• the mesh gauge and the speed of movement of the filter are adapted to the size of the space 48 beneath the filter in order that the pressure increase which arises in the space be able to raise and/or release those bodies which have gathered against the upper surface of the filter.
• the raised and/or released bodies accompany the brush and are displaced to the U-shaped channel 44.
• Efforts should generally be made to ensure that the pressure increase merely occasions a minor raising of the bodies, in that the pressure increase is adapted such that liquid located in the mesh of the filter is retained in the mesh and forms an upwardly directed bubble.
• the filter 41 has a substantially fixed position in the bath and there assumes a location corresponding to that shown in Fig. 3b, i.e. the entire filter is positioned above the level of the liquid surface 54.
• Pressure and evacuation means (not shown), for example of bellows- like arrangement, are connected to the substantially closed space 48 located beneath the filter.
• the employ ⁇ ment of excess pressure, and possibly also of partial vacuum in a space located in conjunction with the underface of the filter and bounded by the filter is also applicable to stationary filters which have a relatively great inclination and which, at their upper por ⁇ tion, are supplied with the liquid and body (matter) mixture.
• bodies gathered against the upper face of the filter are released in a manner corresponding to that described above and this will thereby prevent the mesh and/or apertures of the filter from being blocked.
• the filter member 42 may, in certain fields of physical application, be formed of rods or bars disposed adjacent one another. In such an instance, the spacing between the rods is adapted to the speed of movement of the filter, the viscosity of the liquid and/or the size of the space 48 in order to attain the above-described functions and effect.
• the filter has been shown in applications where the filter describes a pendular motion, it will be obvious to those skilled in this art that the above-described filter action may be obtained in embodiments in which the filter member 42 is disposed for a substantially uniform reciprocal movement, for example a substantially upward and downward movement, with essentially fully retained orientation of the filter member, or is disposed for a uniform rotational movement in the vertical plane.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Filtration Of Liquid (AREA)
• Treatment Of Liquids With Adsorbents In General (AREA)
• Centrifugal Separators (AREA)
• Control And Other Processes For Unpacking Of Materials (AREA)
• Supplying Of Containers To The Packaging Station (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)
• Manufacturing Of Printed Circuit Boards (AREA)
• Liquid Developers In Electrophotography (AREA)
• Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

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Cited By (4)

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Citations (3)

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• 1985
  • 1985-05-17 SE SE8502442A patent/SE452558B/sv not_active IP Right Cessation
• 1986
  • 1986-05-20 WO PCT/SE1986/000232 patent/WO1986006648A1/en active IP Right Grant
  • 1986-05-20 AU AU59043/86A patent/AU591133B2/en not_active Ceased
  • 1986-05-20 BR BR8607111A patent/BR8607111A/pt unknown
  • 1986-05-20 JP JP61503005A patent/JPS63500780A/ja active Pending
  • 1986-05-20 EP EP86903654A patent/EP0259336B1/en not_active Expired - Lifetime
  • 1986-05-20 AT AT86903654T patent/ATE81303T1/de not_active IP Right Cessation
  • 1986-05-20 DE DE8686903654T patent/DE3686950T2/de not_active Expired - Fee Related
• 1987
  • 1987-01-14 NO NO87870138A patent/NO166166C/no unknown
  • 1987-01-16 DK DK021987A patent/DK21987A/da not_active Application Discontinuation
  • 1987-11-09 FI FI874948A patent/FI86260C/sv not_active IP Right Cessation
• 1989
  • 1989-11-02 US US07/430,826 patent/US4956101A/en not_active Expired - Fee Related

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