MATERIAL TREATMENT APPARATUS

Abstract: Material treatment apparatus (10) has a housing (11) with inlet (31) for material to be treated. A helical wall (21) defines an angularly and axially extending flow path for material. Gas can escape through pipe (9) and liquid is discharged through outlet (30). Solids pass on wall (21) to channel (25) to a separate container (27) having outlet (28). Treatment gas can be introduced at nozzles (40) and other treatment material e.g. defoaming agent can be introduced at axially spaced nozzles (43). If sedimentation only is required, pipe (9) can be omitted. The apparatus is compact.

Description: MATERIAL TREATMENT APPARATUS THIS IFVΕTTΪION relates to material treatment apparatus. According to this invention material treatment _: apparatus comprises a housing having an axis, and means defining a liquid flow path in the housing between an inlet and an outlet characterized in that the flow path at least in part extends angularly as it extends axially. -ι - —c. The defining means may define axially space regions of the flow path, the flow paths in the regions extending angularly as they extend axially. The defining means may comprise an helical -.vail. I!; The radially outer edge region of the wall may co p ise a channel. The channel may communicate with a separate outlet at its lower end. There may " be means for introducing treatment 20 material e.g. a gas and/or a liquid into the flov; Oa h. The invention may be performed in various ways and one specific embodiment with possible modifica¬ tions will now be described by way of example with reference to the accompanying drawings, in which Pig. 1 is a side vie? of a material treatment apparatus with some parts omitted; Pig. 2 is a plan view of Pig. 1 on an enlarged scale with the omitted parts inserted; Pig. 3 is a perspective view of part cf Pig. 1 with part removed for clarity; Pig. 4 is a plan view of ig. 5; Pig. 5 is a side view of a modi ication; Pig. 6 is a schematic view; and ig. 7 illustrates a treatment system. A material treatment apparatus 10 comprises a generally cylindrical housing 11 having a central axis and a peripheral wall 12 and closed by end walls 13, 14- Upstanding centrally from the bottom wall 13 is a tube 15 closed at its upper end 16. An I—shaped tube 9 has a central vertical leg 17, which is open at its lower end and which extends sealingly through the top wall 14, and a horizontal leg 18 arranged for connection to a source of reduced pressure or vacuum apparatus indicated schematically at 19- An axially extended spiral or helix 20 is located in the housing 11. The spiral has a downwardly and outwardly inclined helical wall 21 which is sealed e.g. by welding, at its inner edge 22 to the outer surface 23 of the tube 15, and to the outer surface 8 of the leg 17. In the axial space 27 between tube 15 and tube leg 17 the inner edge 22a of wall 21 is free. The wall 21 stops short of the inner surface 24 of the wall 12 and is continued by an I*-shaped channel 25 whose outer edge 26 is sealed, e.g. by '.velding, to the surface 24. The edges 22, 22a, 26 each form a helix. The spiral 20 stops short of end wall 13 and a plate 34 in housing 11 forms the bottom end of volume 30. The wall 21 and channel 25 thus define with the housing 11 a volume 30 which is closed apart from the inlet to pipe 17. A wall 36 extends between two adjacent turns c the spiral to close the spiral at the top so that between the wall 14 and the spiral 20 is a closed volume 37. A closed volume 33 is between plate 34 and wall 13. Volumes 37, 33 are not in communication wit volume 30. In use the volume 30 is normally filled with material being treated. At its lower end the channel 25 communicates with a closed container 27 having an outlet 28 tnroug the wall 12. Material to be treated can be introduced at the top of the vol-αne 30 through one or more, three shown in ig. 1, inlet pipes 31 which extend through the top wall 13 (Pig. 2) or side wall 12 ( ig. 1; ana sealingly into an upper region of the volume 30 between adjacent turns of the spiral. At the lower end of the housing 11 is an outlet 2 from the volume 30. An openable and closabls drain outlet In use the material introduced at inlet 31 descends through the vαlα_ne 30 following initially an axially extended helical path in a region 70 associated with leg 17, then through a region 71 betΛ-een the tube 15 and the leg 17 in which trie flow is less spatially controlled, a.αα then ir_ a.-i axially extended helical path in a regie ' i 72 around the tube 15 to the outlet 32. The angular motion of the material produces a radial pressure difference so that pressure is less at a radially inner .-egior- than at a ial^r outer region so that gas in the material tends to migrate towards the inner region, as indicated schematically by bubbles 33 ig. 7. Air or other gas may be supplied to the volume 30 through inlet nozzles 40 extending from pipe 41 having closable flow control valve 42. There nay be one or more nozzles 40 at each of one or more axial locations. The added air or other gas attracts light particles or bubbles of gas or dissolved gas and assists in transporting this to a radially irmer region. Farther liquid, e.g. a defoaming agent, can be supplied to the volume 30 through nozzles 43 extend¬ ing from pipe 44 with closable flow control valve 45. There a;/ be one or more nozzles 43 at each of one or more axial locations. Samples of the mixture in the volume 30 can be taken through closable sample outlets 45 at one or more axial locations. Tne apparatus may be used in a variety of ways. Por example the input material may be a αixture of liquid and solid material. As tni input liquor descends, solids which are heavier than the liquid will tend to engage the wall 21 and pass therealong into the channel 25 and be carried ' ^γ the spiral motion of tne mixture to the container 27 for remova and, where appropriate, further treatment e.g. cleansing, prior to re-use. The input mixture is thus clarified and the clarified liquor is removed through the outlet 32 either by gravity or a pump 50 In some cases the input liquor is the effluent from another process e.g. paper-making or china clay blending or treatment, and the clarified liquid may be returned to that process for re-use, possibly after further treatment e.g. passing through a cyclone separator. If the liquid-solid mixture contains so- called flotables, these may be removed through pipe 9 due to the reduced pressure in the pipe 9. Where appropriate air or other gas is introduced at 40 to attract particles in the mixture and cause them to float and thus rise up the housing " " and be removed by the suction in pipe 9. cr example this could be applied to an input mixture of water and titanium dioxide. One example of a solid-liquid mixture is water with sand and/or river mud. In another example, the input material is a liquid- liquid mixture e.g. water and solvent. Agair. air or other gas can be introduced at 41 , and/ cr a def oa ing agent at 43 , to cause the solvent to r se and be removed through the pipe 9. In some cases the input material is a liquid- gas mixture e.g. liquid and absorbed air. The air may be caused tσ' separate out wholly or in part by the angular movement of the mixture along the spiral or air or other gas can be introduced e.g. in the form of bubbles to remove the air from the mixture and thus through the pipe 9. The rate of flow of input material through the volume 30 can be controlled bv a flow meter and valve 60 which can be at the input or outlet end, and the input material could be pumped in by pump 61. The arrangement is compact by comparison with a long settling tank; for example the diameter of the housing 11 may be between 3.3 metres to 5.7 metres (8ft to 12ft) with an axial length of 5.7 metres. Although the apparatus has been illustrated in a vertical position, this is not essential and the housing 11 may have other orientations. In some cases it is not necessary to apply suction to pipe 9, the gas can simply pass tnrough pipe 9. The arrangement can be constructed for partic¬ ular uses. Foe example the spiral region above tube 15 can be principally for removal of gas and the spiral region along tube 15 primarily for separation of solids as indicated schematically at 39 Fig. 7 in which the solids are shown as settling and migrating to channel 25. Thus the lengths of tube 15 and pipe 17 and the numbers of associated turns of wall 21 can vary. The rate of flow of material through the apparatus is adjusted to particular circumstances and treatment. The wall 21 can be at different angles to the axis in different apparatus or have a varying angle at different axial positions in an apparatus 10. - 3 - If desired a filter for solids can be incorpor¬ ated. For example a filter <**9 Fig. 4 formed as a circular tray 51 can be disposed above outlet 32 and have a plurality of sectors 52 whic contain for 5 example sand to act as a filter. The tray 31 is rotated step-by-step by motor 53, say one complete revolution in 24 hours, and is a cover 34 for one it the _-P._---._- _. -_-- ectcr c may as above be by both dissolved air flotation and sedimentation. In some cases the Treatment may be sedimentation 13 only and in tnis case the air inlet(s) could be omitted and the tube 13 extend up to the wall 14 (pipe 9 omitted'. zr into sealing engagement wit leg -I rr Because the axial listance between ad.acent 20 turns of cha:inel 23 is relatively small, particles can more readily fall into contact with '.vail 21. In some rases additional material to assist in the treatment is added to the liquor before tne liquor enters the apparatus 10. Thus effluent -"-. from source 30 Fig. 7 can receive added air at 31, these components passing through an in-line mixer 32, the output then receiving added polymer at 33 before passing to inlet pipes 31. The clarified liquid is removed at 84 as above and the solid residues (say 10_ by volume) can be removed, passed through a centrifugal separator 85, then an air dissolving tube 86 and the output of this fed bacl_. to the inlet 31 or to the inlet to the mixer 32, The tube 15 could be moveable up and down in relation to the wall 21 to vary the relative Dositions and extent of the treatment zones.

Claims: CLAIMS 1. Material treatment apparatus comprising a housin (11) having an axis, and means (12, 21, 25) defining liquid flow path in the housing (11) between an inlet (31) and an outlet (32) characterized in that the flow path at least in part extends angularly as it extends axially. 2. Apparatus as claimed in Claim 1, characterized in that the defining means (12, 21, 25) defines spaced regions (70, 72) of the flow path, the flow patns in the regions extending angularly as they exten-J axiall . 3. Apparatus as claimed in Olaim 1 or claim 2, characterized in that the defining means comprises a helical wall (21). 4. Apparatus as claimed in Claim 3, characterized in that the helical wall (21) is inclined to the axis away from the inlet (31). 5. Apparatus as claimed in Claim 3 or Claim , characterized in that the radially outer edge of the wall (21) comprises a channel (25) coinmunicating with a separate outlet (28). 6. Apparatus as claimed in Claim 1 or Claim 2, characterized by a separate outlet (9) for gas. 7. Apparatus as claimed in Claim 6, characterized by suction means (19) connected to the outlet (9). 8. Apparatus as claimed in Claim 1 or Claim 2, characterized in that means (40) are provided for introducing treatment material into the flow path. 9. Apparatus as claimed in claim 8, including axially spaced means (40, 44) for introducing treatment material into the flow path. 10. Apparatus as claimed in Claim 2, including means (40) and means (44) for respectively intro¬ ducing treatment material into the flow path in the region (70) and the region (72).

Inventors: BAGGALEY JACK, BAGGALEY, JACK
Applicants: BAGGALEY JACK, BAGGALEY, JACK
Application year: 1992
Main classification: B01D17
IPC codes: B01D17, B01D21, B01J8, B03B5, B03D1