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WO1998015334A1 - Dispositif de separation comportant un equipement pour commande de sortie - Google Patents

Dispositif de separation comportant un equipement pour commande de sortie Download PDF

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Publication number
WO1998015334A1
WO1998015334A1 PCT/SE1997/001680 SE9701680W WO9815334A1 WO 1998015334 A1 WO1998015334 A1 WO 1998015334A1 SE 9701680 W SE9701680 W SE 9701680W WO 9815334 A1 WO9815334 A1 WO 9815334A1
Authority
WO
WIPO (PCT)
Prior art keywords
helix
liquid
screening device
casing
screening
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/SE1997/001680
Other languages
English (en)
Inventor
Richard Bruke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Spirac Engineering AB
Original Assignee
Spirac Engineering AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Spirac Engineering AB filed Critical Spirac Engineering AB
Priority to AU46416/97A priority Critical patent/AU4641697A/en
Publication of WO1998015334A1 publication Critical patent/WO1998015334A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E03—WATER SUPPLY; SEWERAGE
    • E03F—SEWERS; CESSPOOLS
    • E03F5/00—Sewerage structures
    • E03F5/14—Devices for separating liquid or solid substances from sewage, e.g. sand or sludge traps, rakes or grates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/0012—Settling tanks making use of filters, e.g. by floating layers of particulate material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/0039—Settling tanks provided with contact surfaces, e.g. baffles, particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/02—Settling tanks with single outlets for the separated liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/18—Construction of the scrapers or the driving mechanisms for settling tanks
    • B01D21/183—Construction of the scrapers or the driving mechanisms for settling tanks with multiple scraping mechanisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/2444—Discharge mechanisms for the classified liquid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/24—Feed or discharge mechanisms for settling tanks
    • B01D21/245—Discharge mechanisms for the sediments
    • B01D21/2461—Positive-displacement pumps; Screw feeders; Trough conveyors

Definitions

  • the present invention relates to an apparatus for separation and displacement of bodies, particles and/or similar impurities from a liquid according to the preamble to the independent claim.
  • bodies, particles and/or similar impurities is taken in this description to signify all material which, when it is located in a liquid, comes to rest against a separation apparatus, for example a grid or a screen through which the liquid passes.
  • a separation apparatus for example a grid or a screen through which the liquid passes.
  • Screenings An expression which occurs often for such material is "screenings", consequently, in the continuation of this description, the expression screenings will often be employed for the above-defined matter.
  • solid substances also occurs but will be employed in this description generally exclusively for screenings in which the liquid content has been reduced.
  • the liquid content of the screenings is high.
  • the total solids is generally less than 5-8%.
  • G 8905963 there are previously known apparatuses for removing solid bodies and material from a flowing liquid.
  • These documents describe an obliquely upwardly inclined conveyor screw installed in a channel with flowing liquid containing bodies of solid matter.
  • the conveyor screw is disposed in a path which, in its lower region, forms a part-cylindrical screen surface. Above the water surface, the path is designed as a tube or casing surrounding the conveyor screw. In its upper end, the casing is provided with a discharge aperture. In the region ahead of the discharge aperture, the threads of the conveyor screw are of reducing pitch, whereby a certain compression and dewatering take place of the matter being upwardly transported.
  • capacity in these apparatuses is extremely low.
  • Apparatuses of the above described type are employed for mechanical treatment of restricted flows of municipal waste water, treatment plants or for purifying (screening) polluted liquids, for example water within industries such as paper mills, food industries and slaughter houses.
  • a serious drawback in the prior art technique is that the diameter of the conveyor helix is determined by the maximum liquid flow for which the apparatus is to be dimensioned, since the diameter of the conveyor helix is determined by the radius of curvature of the screen surface.
  • large liquid flows require large diameters of the conveyor helix, which entails unwieldy and expensive designs and constructions.
  • the average degree of efficiency in prior art apparatuses is low. This circumstance is the immediate reason why apparatuses of the type described here have only come into use in relatively limited maximum flows, seldom above 100-125 1/s.
  • German patent application 94113084.1 describes an apparatus with two cooperating screen surfaces, which implies that the above-described drawbacks are partly obviated.
  • the apparatus described in the patent document suffers from the drawback that the increased screen surface is, in its effective extent, restricted unless the construction is made extremely space-demanding and expensive. The reason is that they, according to the description, are oriented parallel with the inclining screen/upward conveyance apparatus.
  • the increased screen surface also requires that the supply channel be expanded in the area of the screen surface.
  • the only demonstrated method of attempting to control the degree of compression and thereby the dewatering efficiency is to vary the length of the "unthreaded" compression space ahead of the discharge opening, i.e. to increase or reduce the length of the "friction plug" which is formed by the conveyed matter.
  • the difficulty in attempting, in this manner, to control the degree of dewatering is obvious, since, in practice, the quantity of screenings per unit of time varies dramatically (the matter "dries" more or less when remaining for varying periods of time during which it is subjected to compression).
  • the present invention relates to an apparatus in which the above-outlined drawbacks have been obviated. This is attained by means of the apparatus according to the characterizing clause of the independent claim.
  • Fig. 1 shows a longitudinal section through an apparatus placed in a channel
  • Figs, la-e show cross sections taken along the lines A-A, B-B, C-C, D-D and E-E in Fig 1;
  • Fig. 2 shows the upper end portion of the apparatus in greater detail
  • Fig. 3 is a longitudinal section through a second embodiment of the apparatus placed in a channel;
  • Figs. 3a-e show cross sections taken along the lines A-A, B-B, C-C, D-D, and E-E in Fig. 3;
  • Fig. 4 shows the upper end portion of the apparatus according to Fig. 3 in greater detail
  • Fig. 5 is a longitudinal section through the apparatus in one embodiment in which it is placed in a container;
  • Fig. 6a is a top plan view of one embodiment of the apparatus with a laterally placed extra screen section
  • Fig. 6b shows the section taken along the line B-B in Fig. 6a;
  • Fig. 7a is a top plan view of a second embodiment of the apparatus with a laterally placed extra screen section;
  • Fig. 7b is a section taken along the line B-B in Fig. 7a;
  • Fig. 8a is a top plan view of a third embodiment of the apparatus with a laterally placed extra screen section;
  • Fig. 8b shows a section taken along the line B-B in Fig. 8a.
  • the Figures illustrate one embodiment of an apparatus for removing bodies and/or particles from a flowing liquid 60.
  • the apparatus includes a lower portion 10 including a screen device 40 and an upper portion 11 including a discharge portion 11a.
  • the apparatus also includes an intermediate portion 12 which forms a conveyor device 12 between the lower portion 10 and the upper portion 11.
  • a conveyor helix 3 is disposed in a path 7 which is formed by the lower portion, the upper portion and the intermediate portion (in those embodiments in which the intermediate portion is included).
  • Drive means 30 are disposed at the upper region of the apparatus.
  • the screen device 40, the intermediate portion 12 and the upper portion 11 from a screen and conveyor device which separates the bodies and/or particles from the liquid and displaces the screenings formed on separation to the upper region of the apparatus.
  • the conveyor helix consists of a helical thread blade 33.
  • thread blade has here been employed without any restrictive import and comprises a helical body whose cross section is, for example, rectangular, conical, trapezoidal, ziggurat-shaped defining surfaces, etc.
  • thread blade may also be taken to refer to a body which is composed of two or more mutually interconnected part helices.
  • the helical thread blade is designated hereinafter generally as "shaftless helix" 33 or "helix” 33.
  • the prime mover 30 is disposed to rotate the shaftless helix 33 about its geometric centre axis 32.
  • the path 7 and the geometric centre axis 32 of the helix make an angle ⁇ with the horizontal plane 5.
  • the intermediate portion 12 and the upper portion 11 are designed with a casing 17 which, with a certain play, surrounds the helix 3.
  • the designation first casing 17 will often be employed.
  • the first casing 17 is of substantially cylindrical design. In both portions, the casing has a cross section which generally includes at least one corner. In the region of the discharge device 51, described below, the casing is generally provided with a substantially circular cross section.
  • the screen device 40 comprises a first portion 41 located beneath the calculated highest liquid level 6a of the liquid which is fed to the inlet portion of the screen device, and a second portion 42 located above the calculated highest liquid level 6a.
  • the wall 17a of the screen device forms a screen surface which is pro- vided with passages 15 for liquids.
  • the dimensions of the passages are adapted to the size of those bodies, particles and/or similar impurities 61 which are to be separated from liquid passing through the screen device.
  • the cross section of that portion of the path which the screen device 40 forms (cf. Fig. la) and the outer radius of the helix are adapted to one another such that, in those portions of the screen device 40 where the helix abuts against the wall 17a of the screen device, this forms a curved surface with a radius of curvature which, in the circumferential direction, substantially coincides with or exceeds the outer radius of the helix.
  • a displaceable casing half 17b (cf. Fig. lb) is disposed in the region of the second portion 42.
  • the casing half generally has a cross section which corresponds to the cross section of the upper half of the first casing 17 in the intermediate portion 12 of the apparatus.
  • the casing half 17b in cooperation with the wall 17a of the screen device substantially surrounds the helix 3 in the lower portion 10 of the apparatus.
  • the casing half 17b is generally displaceable in the axial direction of the apparatus.
  • the displacement of the casing half is preferably automatically regulated in such a way that its lower edge is always located in the region of the surface of the incoming liquid, i.e. above, in or below the surface.
  • the displacement of the casing half is normally controlled with the aid of a level sensor 53 which senses the level of the liquid flowing in towards the screen device.
  • the displacement of the casing in the axial direction of the apparatus is normally controlled such that the casing half in cooperation with the screen device substantially surrounds the entire length of the helix, between the liquid surface and the casing 17 of the intermediate portion 12.
  • the casing half 17b is provided with outlet means 43 for liquid.
  • the outlet means comprise nozzles 43 which are directed towards the wall 17a of the screen device.
  • the nozzles are preferably disposed in two discrete rows which are substantially paral- lei with the geometric centre axis 32 of the helix.
  • control devices are normally included which only permit the one row of nozzles to emit liquid jets, namely that row whose nozzles, in the relevant direction of rotation, direct their liquid jets towards the drive side of the screen device 40.
  • drive side is here taken to signify that area of the screen device along which the major portion of the conveyed matter is displaced on rotation of the helix.
  • the nozzles 43 are, in certain versions, disposed on brackets 44 (cf. Fig. 3 below) which are generally displaceable in the longitudinal direction of the apparatus for moving the outlet devices 43 according as the liquid level varies.
  • brackets 44 cf. Fig. 3 below
  • a number of the highest-located brackets generally have a fixed posi- tion and form an upper portion 44 of brackets whose liquid jets are directed towards the upper region of the second portion 42 of the screen device.
  • the remaining brackets form a lower, movable section 46 of brackets which, during reciprocal movement, emit liquid jets directed at the wall 17a of the screen device above the liquid surface and thereby at any possible screenings located above the liquid surface.
  • the outlet devices 43 emit liquid which pours over the screenings irrespective of where the screenings are located in the region between the liquid surface and the intermediate portion.
  • the guide device and detector 53 adapt the extent of the reciprocating movement to the relevant level of the liquid flowing in towards the screen device 40.
  • Fig. 1 also shows a channel 62 with an upper edge 63 and a channel bottom 64.
  • Liquid 60a, 60b flows through the channel and passes through the screen device 40.
  • the liquid level of the liquid 60a before passing the screen device is higher than the liquid level of the liquid 60b which has passed the screen device.
  • the arrows D mark the flow direction of the liquids.
  • the channel consists, for example, of a concrete or sheet gutter or flume in which the liquid flows.
  • the wall 17a of the screen device merges in the upper region of the second portion 42 in the first casing 17 surrounding the conveyor helix 3 both in the intermediate portion 12 and in the upper portion 11.
  • the first casing 17 is surrounded, at least along a part of its length, by an outer casing 20.
  • this is of a cross section with at least one corner.
  • use is made of a polygonal cross section, as shown in Fig. lc. Embodiments also occur where the cross section is, for example, circular, oval, etc.
  • the casing 17 is, in the upper portion 11, provided with passages 45 for liquid, while the intermediate portion 12 generally lacks such passages.
  • Figs. 1-2 show a drive shaft 18 rotated by the prime mover 30, the shaft being fixed to the helix 3 in order to rotate it.
  • the drive shaft enters at least half a helical turn into the helix 3.
  • an area 16 without helix hereinafter also designated helical- free zone 16.
  • the above-mentioned end will hereinafter often be designated "free end" 34.
  • the first casing is provided with passages 45 for liquid in the region of the free end of the helix. This region prefer- ably comprises only that portion of the casing which surrounds the three helical turns which precede the end 34 and, as a rule, only the last two helical turns.
  • the first casing is moreover generally provided with passages 45 in that portion 16a which is located between the end 34 of the conveyor helix and the dis- charge aperture 14.
  • the first casing has, in the area proximal the upper end wall 54 of the apparatus, a discharge aperture 14. This is generally provided with at least one hatch 50 for the controllable closing and opening, re- spectively, of the discharge aperture. Drive means (not shown in the Drawings) are provided for moving the hatch to the opened position, to the closed position or to an intermediate position.
  • the drive shaft 18 is, in the region of the discharge aperture 14, pro- vided with a discharge device 51 fixedly connected to the shaft and, on rotation of the shaft, pushing accumulated screenings ahead of it in the circumferential direction of the first casing.
  • the distance in the axial direction of the helical -free region around the shaft 18 to the discharge device 51 corresponds to at least approximately half of the diameter of the helix 3 and at most approximately twice the diameter. As a rule, the distance is not greater than the diameter of the helix 3.
  • the helical -free space which is formed around the drive shaft 18 from the free end 34 of the helix 3 and up to the upper end wall 54 of the discharge portion constitutes a compartment for temporary accumulation of upwardly conveyed screenings.
  • the casing is provided with passages 45 for liquid while the intermediate portion 12 has no such passages.
  • a space 26 for accumulating liquid which has been moved into the space via the passages 45.
  • the intermediate portion is also provided with passages, whereupon the outer casing 20 is extended downwards towards the screen device 40 in order to surround that part of the intermediate portion which is pro- vided with passages.
  • the compression of the screenings (as described below) in the upper portion 11 of the apparatus is sufficiently effective for the desired total solids to be achieved for the matter which is to be discharged out of the apparatus.
  • the intermediate portion 12 is provided merely for the screenings to be lifted to suitable dis- charge height and is only a transport section for the screenings. Consequently, the intermediate portion normally lacks passages for liquid.
  • the cross section of the first casing 17 is, in the area along the helical -free portion between the free end 34 and the discharge device 51 preferably not circular, so as to prevent rotation of screenings accumulated in this region. In the area of the discharge device 51, the cross section is substantially circular.
  • the discharge aperture 14 is provided with an ejector chute 80.
  • This has a first wall 81 which is disposed on one side of the discharge aperture 14 and directed in a tangential direction of the cross section of the casing.
  • the ejector chute is provided with a second wall 82 which is opposed to the first. Both walls are interconnected with transverse walls which are oriented such that the ejector chute will have a substantially rectangular cross section. As a rule, the distance between the first and second walls increases with increasing distance from the discharge aperture 14.
  • the discharge device 51 is in the form of a vane 51 which is per- manently fixed at the drive shaft 18.
  • the cross section of the vane is preferably conical, with the tip of the cone directed from the centre axis of the drive shaft. On rotation of the drive shaft, the tip of the cone passes with slight clearance the inner surface of the first casing.
  • the device will, on its rotation past the area of the discharge aperture 14, act on matter which is abutting against the device with forces at a direction which substantially corresponds to the direction of the ejector chute.
  • displacement of matter out through the discharge aperture 14 will be facilitated.
  • a central stationary mechanical shaft 19 which is fixed to the lower transverse wall (bottom wall) 49 of the apparatus.
  • the shaft passes through the central cavity of the helix 3.
  • the dimensions of the shaft are less than the diameter of the inner cavity of the helix.
  • the shaft is designed with a cir- cular cross section, while in other embodiments it has an oval cross section.
  • the shaft is provided with external ribs and/or has a cross section with at least one corner.
  • Fig. 4 shows the upper portion 11 according to the embodiment il- lustrated in Fig. 3 in greater detail.
  • the drive shaft 18 is not mechanically connected to the mechanical shaft 19.
  • the length of the mechanical shaft 19 is selected such that the shaft terminates adjacent the rotary drive shaft 18.
  • the width of the thread blade 33 in the radial direction and the radius of the shaft are selected such that, when the shaft is inclining, the force of gravity will bring the thread blade into abutment against the wall 17a of the screen device 40 and/or against matter located between the thread blade and the wall 17a.
  • Those parts of the thread blade which are located in the intermediate portion 12 are also displaced by gravity into abutment against the casing 17 and/or against matter lo- cated between the thread blade and the casing.
  • the spiral is free-running, i.e. there is no abutment against the first casing 17 of the apparatus or against the central mechanical shaft 19.
  • Fig. 5 shows one embodiment of the apparatus where there is no intermediate portion.
  • the apparatus is placed in a container 2 with an inlet 21 and an outlet 22 which is provided with a valve (not shown in the Figure) for opening and closing the outlet.
  • the container includes a chamber 2a which is supplied with liquid through the inlet 21, and a space 2b from which liquid is removed through the outlet 22.
  • the wall 17a of the screening device 40 forms a partition 17a between the chamber 2a and the space 2b.
  • a detector 53 is provided for sensing the liquid level in the chamber and moreover a control means (not shown in the figure) opens and closes the outlet valve when the liquid level reaches a predetermined lowest level and opens the outlet valve when the liquid level reaches a predetermined highest level.
  • the outlet 22 of the container is dimensioned for a flow capacity which corresponds to or exceeds the flow capacity of the inlet 21.
  • Figs. 6a, b show one embodiment in which the apparatus includes an extra screening device 70 provided with passages 15a for liquid, this device being hereafter generally referred to as extra screening portion 70 which is disposed beside the screening device 40.
  • the screening device 40 is placed adjacent the one side wall 65 of the channel 62.
  • the extra screening portion 70 is disposed between the second side wall 66 of the channel and the screening device 40.
  • the extra screening portion 70 makes an obtuse angle ⁇ with the upstream channel wall 66.
  • a transverse wall 67 which is impenetrable for liquid (cf. Fig. 6b).
  • the extra screening portion 70 connects to the upper edge 69 of the trans- verse wall.
  • a scraper device (not shown in the Figures) is provided for displacing bodies which have accumulated against the extra screening portion towards the screening device 40.
  • a vertical wall 68 connects the extra screening portion 70 with the screening device 40.
  • the lower portion 68a of the wall flush with the edge 69 is impenetrable for liquid, while its upper portion 68b is, in certain embodiments, designed as screening device.
  • the extra screening portion 70 is, as a rule, placed a distance from the bottom 64 of the channel. This distance is determined by the calculated size of normal flow through the channel and is selected such that liquid passes through the extra screening portion only when the flow in the channel exceeds a predetermined flow. There will hereby be achieved the positive effect that, on flow which is less than the predetermined flow, all liquid passes through the screening device 40. This is a factor which entails that the desired size of the flow, and thereby the desired minimum flow rate will be maintained through the screening device 40 even in the event of slight flow volumes. An increased flow prevents sedimentation ahead of the screening device.
  • the extra screening portion 70 with the wall 67, as well as the extra screening portion 68b with the wall 68a are, as a rule, of vertical extent in the liquid 60.
  • the angle of inclination of the screening device 40 is, as a rule, 30-50° to the horizontal plane.
  • the width of the screening device 40 open to the liquid flow is preferably approx. 30-50 cm and the majority of channels in treatment plants throughout the world seldom display widths exceeding 2.5 m. The majority of widths is less than 1.2 m.
  • the screening device 40 and the screening portion 70 together cover the entire width of the channel and together offer an optimum screening surface for the onward flowing liquid.
  • the angle ⁇ may be permitted to vary without operation being jeopardized or without the design and construction being appreciably more expensive.
  • the present invention affords the possibility of simple dimensioning of the screening surface in view of liquid flow and demands on the size of the screen aperture, at the same time as the screening device 40, the intermediate portion 12 and the upper portion 11 are permitted to be dimensioned according to calculated maximum quantity of screenings which need to be handled per unit of time.
  • the screening device is placed between the side walls 65,66 of the channel, extra screening portions being provided between the screening device 40 and the side walls 65,66 of the channel on both sides of the screening device.
  • Figs. 7a,b show yet a further embodiment of the present invention in which extra screening portions 74 are provided between the screening device 40 and the walls of the channel on both sides of the screening device 40.
  • the extra screening portions are placed vertically in a man- ner corresponding to that previously disclosed for the embodiment according to Figs. 6a,b.
  • the screening portions are vertically oriented and have a cross section which constitutes a portion of a circle periphery.
  • the screening portions thus form partly cylindrical screening surfaces 75.
  • a scraper device 71 is disposed on an arm 72 rotatably about a vertical shaft 73. While this embodiment is shown with two extra screening portions, it will be obvious to a person skilled in the art that, in other embodiments, only one extra screening portion is included which is placed corresponding to that shown in Fig. 6a.
  • Figs. 8a,b show still a further embodiment of the extra screening device 70.
  • Fig. 8a which shows the extra screening device from above, this is disposed between the second side wall 66 of the channel, and the screening device 40 which is placed adjacent the opposed side wall 65.
  • the extra screening device 70 includes a cylinder 70 rotary about its centre axis and whose circumferential surface is provided with perforations or apertures 15a so as to form a screening surface 77 through which liquid flowing in the channel may pass.
  • the centre axis of the cylinder is substantially vertically oriented.
  • the cylinder 70 is disposed to rotate in such a direction that material entrapped on its front side (the side facing towards the liquid flow) is displaced on rotation of the cylinder substantially horizontally in a direction towards the inclining screening device 40.
  • a scraper device 76 oriented in the axial direction of the cylinder 70 is disposed adjacent the circumferential surface of the cylinder and is placed such that material scraped off falls down upstream or towards the screening surface which is formed by the wall 17a of the screening device 40.
  • a "box" 79 which is impenetrable for liquid and whose upper surface 69 is in conjunction with the bottom periphery 78 of the rotating cylinder 70.
  • the box 79 has, as a rule, a wall 68a which faces counter-currently and which corresponds to the above described lower portion of the vertical wall 68 which is impenetrable for liquid.
  • the wall 68a of the box is of an orientation which entails that there is formed, between the wall 66 of the channel and the wall of the box, an obtuse angle corresponding to the angle ⁇ previoiusly defined in this description.
  • the design of the box entails that, in a manner corresponding to that disclosed above, there is formed upstream of the screening device a flow path tapering towards the screening device 40 for the flowing liquid. This design of the box entails the advantage that the flow rate is maintained even in small flow volumes and that the risk of sedimentation is reduced during those periods when the liquid flows are slight.
  • the design with the rotary screening cylinder in accordance with the foregoing entails that liquid passes through the circumferential sur- face of the cylinder in both directions, i.e. also from inside and out, which gives the possibility of auto-cleaning of the apertures in the circumferential surface.
  • Extra cleaning of the apertures of the cylinder when they are located on that side of the cylinder which is downstream, is provided in certain embodiments by means of vertically fixed nozzles 43 which spray liquid against the inside of the circumferential surface of the cylinder.
  • cleaning devices not shown in the Figures
  • such as brushes or scrapers remove residual matter from the outside of the cylinder when its circumferential surface passes the cleaning devices.
  • the incling screening device 40 is placed centrally in the channel with one screening cylinder 70 on both sides of the screening device, the screening cylinders forming extra screening portions in the apparatus.
  • the purpose of the casing is to ensure efficient inward transport of screenings floating on the liquid surface and, at the same time, to render the upward transport operation more efficient.
  • outlet devices (nozzles) 43 spray liquid jets against screenings displaced in the path 7
  • soluble impurities in the liquid for example biological impurities
  • This liquid spraying also entails that the bodies and/or particles are moved towards the wall of the screening device 40, which improves efficiency in the transport by the helix 3 of the bodies and/or particles.
  • the plug will generally remain substantially intact in its end located most proximal the helix, while matter in the opposite end of the plug will be broken loose from the plug in connection with the discharge through the discharge aperture 14.
  • the degree of compression determines the size of the reduction of the liquid content of the matter, and thereby the total solids of the material passing through the discharge opening 14.
  • the degree of compression is controlled by the force which is required to open the hatch.
  • the apparatus is provided with control means for adjusting the requisite force.
  • the increasing compression of the screenings entails that a steadily increasing torque is required to rotate the helix 3 fixedly connected to the drive shaft 18 and the discharge device 51.
  • An automatically operating regulation of the opening and closing of the hatch, and thereby of the liquid content of the screenings or the compression will be obtained in that the hatch 50 of the discharge opening 14 is preten- sioned, for example mechanically or pneumatically.
  • the degree of compression of the material is adjusted by setting (e.g. by modifying the pretension- ing of the spring) of the total force which the matter is to apply against the hatch in order for this to be opened or closed.
  • the degree of compression is adjusted in that a device (e.g. a hydraulic piston, a pneumatic piston, an electro-mechanical operating device, etc.) opens or closes the hatch when the driving power for rotating the helix passes a pre-set value (as a rule the current strength is measured).
  • a device e.g. a hydraulic piston, a pneumatic piston, an electro-mechanical operating device, etc.
  • the total force which is required to displace the plug towards the discharge device determines the total solids of the matter which is discharged out of the apparatus.
  • the degree of compression increases and thereby the total solids of the material which is discharged out of the apparatus.
  • the apparatus includes an intermediate portion 12.
  • this constitutes merely a conveyor portion whose length is adapted in response to the level at which the discharge of the matter out of the apparatus is to take place. Since the technical effect of the apparatus is only dependent upon the lower portion 10 of the apparatus and the upper portion 11 of the apparatus, certain embodiments lack the intermediate portion 12.
  • the above-described combination of screening device 40 and extra screening portions 70,74 makes it possible to dimension the size of the total screening surface in view of the largest and smallest liquid flow and, regardless of this factor, to dimension the transport capacity of the screening device 40, the intermediate portion 12, and the upper portion 11 in accordance with the expected quantity of screenings per unit of time. Despite the increase of the permitted maximum liquid flow which the extra screening devices made possible, the size of the flow area in minimum flow will remain unchanged.
  • the described embodiments with extra screening portions offer efficient screening combined with horizontally directed advancement of entrapped screenings to the inclined screening device 40. Figs.
  • 6a, b show one embodiment in which, for example the dimensioning of the apparatus, the extra screening surface 70 and thereby the permitted maximum liquid flow may readily be increased by altering the angle ⁇ between the extra screening portions and the wall or walls 65,66 of the channel.
  • the reduced flow areas of the screening surfaces is compensated for by an increase of the obtuse angle ⁇ between the extra screening device 70 and the channel walls 65,66.
  • problems often occur in the accumulation of sedimented matter ahead of the screen grid in channels at, for example, water treatment plants.
  • the accumulation is because the channels are dimensioned to handle flows of greatly varying sizes.
  • the channels are dimensioned to permit large maximum flows, at the same time as, during long periods of time, the flows may be very small.
  • the flow rate is extremely low, for which reason matter sediments ahead of the screen grid of the channels.
  • the problem inherent in sedimented matter is eliminated in that the flow rate ahead of the grid is maintained even in the event of small flows in the channel, because the tight wall portion 67 beneath the extra screening surface 70 concentrates the flow such that liquid only passes through the passages 15 of the screening device 40.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Hydrology & Water Resources (AREA)
  • Public Health (AREA)
  • Water Supply & Treatment (AREA)
  • Sink And Installation For Waste Water (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
  • Filtration Of Liquid (AREA)
  • Separation Of Solids By Using Liquids Or Pneumatic Power (AREA)

Abstract

Cet appareil permettant d'extraire des corps (61) d'un liquide en écoulement (60a) comporte une hélice rotative de convoyeur (3) placée sur un trajet (7) défini par un carénage (17). La partie inférieure (10) du dispositif constitue un dispositif de criblage (40) et sa partie supérieure (11) un élément de décharge (11) pourvu d'un orifice de décharge (14). Des moyens d'entraînement mettent l'hélice du convoyeur en rotation. La partie inférieure comporte une partie (40) pourvue d'une ouverture donnant à contre-courant et, dans cette partie, le carénage délimite le dispositif de criblage (40). L'hélice du convoyeur (3) s'arrête à une certaine distance de l'orifice de décharge (14). Entre l'extrémité (34) de l'hélice du convoyeur et l'extrémité supérieure (13) du carénage (17), se trouve une zone dépourvue d'hélice (16) dans laquelle les corps s'accumulent, lesquels corps sont enlevés, au moyen de l'hélice du convoyeur, de la partie inférieure (10) du dispositif. L'orifice de décharge (14) est pourvue d'une butée mécanique (50) permettant de commander l'ouverture et la fermeture de l'orifice de décharge et, partant, de commander le taux de compression des matières accumulées dans la zone dépourvue d'hélice.
PCT/SE1997/001680 1996-10-07 1997-10-07 Dispositif de separation comportant un equipement pour commande de sortie Ceased WO1998015334A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU46416/97A AU4641697A (en) 1996-10-07 1997-10-07 Apparatus for separation including means for controlled output

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9603688A SE507500C2 (sv) 1996-10-07 1996-10-07 Separationsanordning försedd med transportspiral och organ för styrd utmatning
SE9603688-4 1996-10-07

Publications (1)

Publication Number Publication Date
WO1998015334A1 true WO1998015334A1 (fr) 1998-04-16

Family

ID=20404184

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1997/001680 Ceased WO1998015334A1 (fr) 1996-10-07 1997-10-07 Dispositif de separation comportant un equipement pour commande de sortie

Country Status (3)

Country Link
AU (1) AU4641697A (fr)
SE (1) SE507500C2 (fr)
WO (1) WO1998015334A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002011853A1 (fr) * 2000-08-04 2002-02-14 Rudolf Bischof Gmbh Technische Handelsvertretungen Dispositif d'extraction permettant l'extraction de liquide a partir de corps solides, et son utilisation
DE10361786A1 (de) * 2003-12-31 2005-02-17 Kuhn, Jürgen Vorrichtung zum Trennen von mit organischem Material verschmutzten anorganischem Material aus einer Schmutzflüssigkeit

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3122131A1 (de) * 1981-06-04 1982-12-23 Günther 7913 Senden Abel Vorrichtung zur entnahme und entwaesserung von feststoffen aus fluessigkeiten, insbesondere aus gerinnen von klaeranlagen
DE4143376A1 (de) * 1991-06-28 1993-04-29 Hans Georg Huber Kompaktanlage zum abscheiden und entfernen von rechengut und sand aus zulaufgerinnen
EP0565898A1 (fr) * 1992-04-07 1993-10-20 Hans Georg Huber Dispositif pour séparer des produits solides d'un liquide avec une surface de séparation cylindrique, perméable à ces liquides et pour l'enlèvement des produits solides
WO1995019212A1 (fr) * 1994-01-13 1995-07-20 Noggerath Holding Gmbh & Co. Kg Dispositif de nettoyage de solides contenus dans des eaux residuaires

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3122131A1 (de) * 1981-06-04 1982-12-23 Günther 7913 Senden Abel Vorrichtung zur entnahme und entwaesserung von feststoffen aus fluessigkeiten, insbesondere aus gerinnen von klaeranlagen
DE4143376A1 (de) * 1991-06-28 1993-04-29 Hans Georg Huber Kompaktanlage zum abscheiden und entfernen von rechengut und sand aus zulaufgerinnen
EP0565898A1 (fr) * 1992-04-07 1993-10-20 Hans Georg Huber Dispositif pour séparer des produits solides d'un liquide avec une surface de séparation cylindrique, perméable à ces liquides et pour l'enlèvement des produits solides
WO1995019212A1 (fr) * 1994-01-13 1995-07-20 Noggerath Holding Gmbh & Co. Kg Dispositif de nettoyage de solides contenus dans des eaux residuaires

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002011853A1 (fr) * 2000-08-04 2002-02-14 Rudolf Bischof Gmbh Technische Handelsvertretungen Dispositif d'extraction permettant l'extraction de liquide a partir de corps solides, et son utilisation
DE10361786A1 (de) * 2003-12-31 2005-02-17 Kuhn, Jürgen Vorrichtung zum Trennen von mit organischem Material verschmutzten anorganischem Material aus einer Schmutzflüssigkeit

Also Published As

Publication number Publication date
SE9603688D0 (sv) 1996-10-07
AU4641697A (en) 1998-05-05
SE9603688L (sv) 1998-04-08
SE507500C2 (sv) 1998-06-15

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