GB2248407A - Apparatus for clarification of sewage - Google Patents

Abstract

An apparatus for clarification of industrial sewage comprises a cylindrical chamber with a conical bottom 2 having an outlet 6 for settled sludge and an inlet 7 for the sewage, dosed with flocculant. Clarified liquid leaves the chamber by peripheral weir 10. The inlet 7 is extended upwards by pipe 12, whose perforations are more widely spaced towards the top, and this pipe is enclosed by tubular baffle 13 whose perforations decrease in size upwards. The bottom of the chamber encloses tubular baffles 16 and conical baffles 19, above which are generally radial baffles 17, 18, inclined to the horizontal. A bell 22 and fan 24 apply suction to the top of pipe 12 and baffle 13 to remove bubbles from the incoming sewage, and external ducts 27 recirculate sewage from the bell to a lower annular passage 25 with openings 26 into the bottom 2 of the chamber. <IMAGE>

Description

APPARATUS FOR CLARIFICATION OF 1"DUSTRIAL S3VAGE The present invention

relates to the treatment of industrial sewage, to a device for separation of suspended solid particles from liquids by precipitation in presence of flocculants and, more particularly, to an apparatus for clarification of industrial sewage.

The disclosed apparatus for clarification of indust- rial sewage can be used to advantage for purification of polluted industrial sewage mainly containing fine suspended solid particles not exceeding 0.1 mm in size which are repeatedly used in the technological process of a certain industry, for example at flotation concent- rating mills, for purification of industrial sewage.

With the purpose of ecological environmental safety, everz industrial enterprise snall strive, on the one hand, for a maximum reduction of fresh water consi;Liption by using it repeatedlj in t6e technological process and, on the other, for the greatest degree of purification of the contaminated industrtal sewage discharged into the envirorE2ant. The repeated utilization of industrial water in the technological process calls for its continuous or periodical purification to the state of clarity. '.'iidely used nowadays in industrial practice for clarification of industrial sewage mainly containing fine suspended solid particles are thickeners, settlers and clarifiers. Intensification of technological process- es involving the use of industrial waters and purification of contaminated industrial sewage containing fine suspended solid particles calls for a continuous improvement of the capacity and efficiency of the thickeners and clarifiers used.

Intensification of clarification of such sewage is usually achieved by the use of high-molecular flocculants. In the course of sewage clarification the fine solid particles settlirL in the form of floccules form C> a steady t--ree-d-i..iensio-.lal structure which interferes wit'n unloading of slurry from purifying apparatuses and causes frequent breakdowns of the slurry unloading mechanism in the thickeners. Therefore, the apparatuses 0 for clarification of industrial sewage usually incorpo- rate mecha.i.i.snns for mechan,-iJ-.ca.3, n-f suc'n a three-dimensional structure in the course of -a-nload-Jn,,- of the slurry from the apparatus or devices .C'3r its destruction with sets of liquid.

The use of high-molecular flocculants for clarifi- cation oil industrial sewa,,.e containing surfactants in W the for.m of flotation reagents and, particularly, foam conduces to the formation of floccules generators, containing gas-air, oil-like and inorganic components which reduces their precipitation rate and, consequ- ently, capacity of apparatuses. This is caused by the fact that the movement of industrial sewage containing surfactants and organic and inorganic sub- 3 - stances is accompanied, as a rule, by formation of gas and air bubbles therein. This is caused by ejection of air during turbulent motion of the liquid. The higher tge concentration of these surfactants in the liquid the greater is its saturation with gas and air bubbles in motion. The liquid is most intensively saturated with gas bubbles by changes in the direction of its flow and jet-type ejection inevitable during transportation of industrial sewage to the clarification apparatuses and when it pass- es directly through the apparatuses. The gas bubbles in the polluted industrial sewage interferes witn its inter,sive clarification because the gas bubbles coming to the surface in the clarification zone carry the slimy particles to the layer of clarified water due to their flo- cular flotation-and tarbalent mixing, The presence of gas-air, oily and some inorganic components in the industrial sewage makes the formed floccles loose, light -ation and easily floatable whicb reduces their precipit rate and, as a consequence, impairs the efficiency and capacity of clarification of industrial sewage.

Known in the prior art is an apparatus for clarification of industrial sewage comprising a vertically-installed cylindrical chamber for circulation of industrial sewage said chamber having a cone-shaped bottom compris- ing a branch pipe for feeding in the polluted industrial sewage with flocculants, the outlet hole of said branch pipe being arranged along the axis of the cylindrical chamber for circulation of industrial sewage, and a branch pipe for discharging the slurry, a circular trough for draininb the purified industrial sewage secured on the outside of tie sewage circulating chamber at its upper edge, and partitions accommodated in said circulatin6 cnamber for settling of solid particles, the surfaces of said partitions beinE inclined towards the axis of the cylindrical sewa;e circulatinE chamber, and at least one separatint partition in the forml of a body of revolution nita noles intended for distributing the polluted sewage ovar the volume of the circulatinE clamber, said separating partttion beinE installed along the axis of tie sewage circulatin6 cLamber, in its central part.

In said sewage clarification apparatus the separatin, partition is arraneed, essentially, along the nelaLt of n-e ccnesLayed bottom, its upper edge is arran.ed somewhat 06her than rae joint between the conesnaled bottom and the cylindrical part of the caamber. 20 aplaratus also comprises two groups of partitions for settling of solid particles consisting, each, of a set of conical coaxialll installed suells. One 8roup of conical shells is installed in the cone-shaped bottom and the other one, in the cylindrical part of the chamber, between its upper edge and the upper edge of the separatinG partition, In said other Group of conical shells their uases of a smaller diameter are directed to the upper edEe of the cylindrical sewage-circulatint chamber.

Such an arran;ement of the separating partition and of the partition., for s ettlinj. of solid particles -e sepacreates a conical zone above trie upper edge of tL rating partition, said zone tapering towards the upper ed,--.,e of the cylindrical sewage-circulating chamber which offers resistance to the flow of gas-air bubbles liberated from the delivered polluted industrial sewage and conduces to the formation of loccules with a Eas phase which, in the loub ruri, le..,pai-rs the capacity of the apparatus for clarification of industrial sewage, the 10 efficiency and quality of its puri:ication.

Another previously known apparatus for clarifica- tion of industrial sewage comprises a vertically-install ed cylindrical sewaje-circulatine chamber with a cone shaDed bottom secLred on which is a branen pipe for feed 1 ing, in polluted sewage,.,,it-h.flocculants whose outlet C U hole is arranbed alonb t.e axis of the cylindrical sewa6e circulating cha!-,ber, and a slurry-discharging branch fied sew- pipe, a circular trou6.L for a dra--nin6 the piLL.i awe secured on tne outside of the cylindrical sewage- circulating chawber, at its upper edge, and partitions acco=odated inside the cylindrical sewage-circulatin6 chaiber, for settlin, of solid particles, the surfaces of said partitions beini inclined towards the axis of the cylindrical se.-jape-cire-latiri.chamoer, and at least one separatin,, partition in the form of a body of revolution witi, holes for distributing the polluted industrial water over tne volume of tae cylindrical se- waEe-circulatiri,-- chaiber, installed along. the axis 02 said cnamber in its central part, the upper ed,--e of said partition oeinr-_- arranSed, essentially, level the W upper edge of the cylindrical sewage-circulating chamber.

In said apparatus for clarification of industrial se,,va.r7,e the separatin,_ S artition, is installed along the enzii.e heiGht of tne claGoer to the level of its upper ede and the gas-air bubbles are liberated in a natural,.ay, from the surface o2 tue sewage in the chamber. The parttions for setting of solid particles in the form of conical shells whose large-diameter bases face the upper ed:e of the sewac;e-circulatin6 chamber do not offer any resistance to the flow of gas-air bubbles. Howevei, in tLe course of natural liberation of -as-air bubbles fro:-, -cr-.,e surface of z...e sewage continuouslj delivered into the chamber at least 50', of i-us -_as component participates in the formation of floccules witr, a Gas phase, i.e. floccules which retard the precipitation of solid particles whica, in the lon, run, reduces the capacity of -,ie sewa,-,e puri-fication apparatus, impairs the efficiency and quality of purification.

An object of the invention lies in raisin,;-:- the cathe a,,aratus i:o-,. clarif o- J'ication of industrial sewa-e, the ef-liciency and quaLity of sewaz-e purification.

The essence of tne- invention consists in that the cylindrical sewag_ecirculatinf,,. chaLiber in tne apparatus for clarification oil industrial sewa-_e is arranged ver- ticallir; secured on t..Le conical botton of the sewagecirculatinF- cha:abe-L are a branch pipe for feeding the polluzed industrial water witL flocculants, whose outlet hole is arranGed alon,' the axis of the cylindrical sewage- C-> eirculatinf,. cha;nber ar,12 a slurry-dischargin,-- branch pipe; secured on the outside of the cylindrical sevja-.,e-ci--,culatin,--, ena-oei. at ius uP,er edge is a circular trough for draining the purified sewage; located inside the cylind.rical sewatSe-circulatin-. chia:ilbe:c. are partitions for settling of solid particles, the surfaces of said partit.Lons beinF,., inclined to the axis of the cylindrical sewage-cir cr-aibe--.; tnere is at least one seDaiatin., parti tion installed alont,. tne axis c tLe cylindrical sewage eircLzlatin,;,,,. cha,,i',bez in i-js cenIL-ral part, said partition navin, ilc)l,--s distribiti-n.-, t,.,e polluted industrial water over the volume o-f the cylii,-rical sewa,,,;,.e-circulat in cnalber, tde upper ediSe o.;L' said partition beiri ar ranr,ed essentially level with the upper edge of the cy lindrical sewa6e-ci-lc"la bin,-_ installed above tne Uition is a press uret-i;-.ht be' se- e CA ,ai,atinf-par' ll-shaped hous- Lower edge is located belo.,,,; -kll:ie upper edge o--' the se,aratin- partition inside the cylindrical sewagecircul-tinjchaL:ioer; the pressLueti-h-" bell-shaped housinkj corniiunicates Y;ith an air- rarefaction reans.

It is practicable that 'he apparatus for cl--rification of industrial sewage, accordinc. to the invention, r_ with partitions for settling of solid particles in trie - 8 7 coaxial conical shells installed successively f orm of along the height of the conical bottom Ath a gap relative to its walls, should contain a circular header arranged outside of the cylindrical sewage-circulating chamber in its lower part, co=unicating with the gap between the conical sLells and the conical bottom, and 1 a F 1_ ,roup of hoses located outside of the c.-Y-lindrical se- wage-circ,.lati..,,i,. cliaiDer and connected w-Lti., ttle pressuretight bell-shaped housinr-. at one end and with the circular header at tLe ouher.

Install-st-Lon of tne pressuretight bell-shaped housin---. connected witr, the air rarefaction means above r-,j th-- surface of industrial sewage continuously delivered se-,,a--.e-ci:i,c-lat-ici; c,, --- to f -111 t, (D --- aUlber builds x) a rare- faction -Nhic. inuensifies liberation of -as-air bubbles inustrial sewa,e.

For eza--p2-e, the rarefaction of air above the surface w-ose area amounts to about 0.1 of the entire sarface area of the industrial-sewagecirculatinf.,. c _, hamber C a pressure o-L frow 0.07 to 0.08 1-Pa ensures libe- E the gas component of industri- ration o-;' at least 70% Of al sewace and iLaproves tre cai,,acity o-, Vh apparatus for clarification of industrial sewage by at least 1.4 times. In taiss case the sewage purification rate amounts to not less than 98%.

Thus, the improvement of capacity of the disclosed ap-paratus for clarification of industrial sewage is ensured by forming more compact easilj-prec-ipizatinE floccules and preventing floccular flotation.

The provision of noses connectin6 the pressuretight housing witn the circular header pernits to increase tue su--face area of industrial sewage witri a wore inuensive liberation of F.as wnich also improves capacity of the apparazus fol, ciarification of industrial sewa_-e.

Now the invention will be explained by way of ex- a--7ples with reference to the accompanying d--!,awin,.,-.s in wLich:

Fif,. 1 is a eneral view of the apparatus for clarifica.-'.-ion of industrial se-wage according to the in15 vention, parCial longitudinal section; Fi,. 2 is the top view of the a..-aratus for clarification of industrial sewage according to the invention; Fie-. 3 is a section along line III-III in Fig. 29 enlarged, sho-wing the upper part of the cylindrical chainb- er with a pressure-tight bell-shaped housing according to tLe invention; Fig. 4 is fra--ment A in Fig. 3, enlar;:.ed,.

t-- C) Fi6. 5 is a section alon6 line V-VAn Fi6. 4, enlarged.

The apparatus for clarification of industrial sewage coisprises a cylindrical chamber 1 (Fig. 1) for circulation of industrial sewa6e to be purified. The cylind- rical chamber 1 has a conical bottom 2 anj is installed vertically on support_-ng members 3 connected with a Lra2e 4 by, sa_v, a screw joint.

Adjoining the conical bottom 2 is a slurry-collect in, poc,:.et 5 on is secured a slurry-discharginL; branch pipe 6. _13esides, the slurry-collecting pocket carries a branch pipe 7 for feedinj--- the polluted indust ri-!zl water with flocculants. The industrial sewa6.e puri fied in tLe disclosed a,Daratus for clarification of in dustrial sevia.--e Lostly contains fine sus-.--nded particles r; ki not more tr.,an 0.1 wm in size. It is known that the fine solid particles suspended in industrial sewa-.e form floccules capable of precipitating quickly. As a rule,.c)l,jaci,y.Lamiaes are u.sed as flocculants. The outlet hol 8 of the branen pipe 7 for feeding po21uted industrial water is arranged alonF. the axis 0 of tLe cylindrical Z_ se,,-jage-circulating chaLber 1.

The apparatus for clarification of industrial,- sewage also coiprises a circular trough 9 for draining the purified industrial water, secured outside of the c,lindrical sewage-circulating chamber 1, at its upper edge 10. Saia trou,L.L 9 for draining the purified sewage is defined by 'the upper portion of tjl.-ke cylindrical chamb- lindrical saell arrat.Lged coaxiaily out- er 1 and trie cy. side of tnis portion of the cylindrical chamber 1. The bottom 01' the troufn 9 for draining the purified sewage is inclined towards the cylindrical shell and is provided with a branch pipe 11 for discharging the puri- 1;:

- -1 e fied sewage from the apparatus.

The apparatus for clarification of industrial sewage also comprises at least one sepa:l,atin; partition in the form of a body of revolution with holes for distributing the polluted industrial water over the volume o' the cylindrical sewage-circula-Gin6j c.,aioer 1. The se- fL paratinpartitions way be other conical or cylindrical t-- in shape. In this eibodiment of the apparatus for clarification of industrial sewa,-,,,e shlown in the drawing there are two se cl paratinL- partitions 12 and 13 in the form of two coaxiall.-,--arranged pipes installed vertically along the axis 0 of the cylindrical sewage- circulatinn- chamber C__ 1 in the central part of said chamber 1 t-rou,6hout its - a ba.,-- betweerl tneia. The upper edges of the i.Lei6Lt wit.l jcz separatin- partitions 12, 13 are arranged, essentially, level with the upper edge 10 o-" tLe cylindrical cnamber 1. The separating partitions 12, 17 separate the zone 11 of delivery of the polluted industrial water where the flow of said water is of a turbulent nature frow the sew age puri -ication zone where the flow of industrial water is, essentially, o. a laminar nature. The pipe forming the internal partitijn 12 is arranr-ed alon6 the liei:ht -he cylindrical sewage of the conical bottom 2 and of t circulating chamber 1. The lower edee of this pipe joinse the branch pipe 7 for feeding the polluted industrial wat er. The outer pipe forming the set-,aratin,. partition 13 11 - is arranted along the height of the cylindrical sewage- circulatinChamber 1. The separatinj:, partition 12 has r) holes 14 for distributing the polluted water over the volume of the cylindrical sewage-ci-culating chamber 1; said holes are of the sa=e diameter and the distance bet- ween sai holes 14 grows from underneath upwards. The partition 15 has noles l for distributing industrial sewa;:,e over t-.e volume of the cylindrical sewage-circulat- W in.7 cLamber 1, said holes being arranged in a staggered order at the same discances fro;i one another. The dia- lc) meter of the holes 15 diziiniSnes from underneath upwards. This sia. :e anj distribution of holes 14 and 15 in th-d separatin, partitions 12 and 13, respectively, are necessary for creating, a quiet laminar nature of the move,-ent of upper layers of the sewage being puri- A=an-_7ed alontne height of the conical bottom 2 C) of t..-- cyl-li-.--,,,4rical se-.va6e-circulatin,-,, cha--ber 1 is a cf four equispaced cylindrical shells 16 installed f tLe separat- successively outside of tLe lo.,.er Dortion o in- partition 12 along the axis 0 of the caamber 1. The diameters of tiese cylindrical shells 16 grow from the lower ed6e of the separating partition 12 towards the lower ed,e of t.,.e se - partition 13. Th,tse cyli-ind r_ paratirib rical shells 16 are aimed at destroying the three-dimen sional structures of the flocculated slurries by creat in5 concentric flows of sewage in the slurry-discharging zone thus acceleratin; the eLLptyinE o-- trie slurry-collec- ting pocket 5 Accom-odated in the cyiindrical sewage-circulatin, chamber I are also partitions for settling of solid par ticles whose su:L-faces are inclined towards the axis 0 of tae cylindrical sewaGe-circulating chamber 1.

One Group o'L such partitiotis is constituted by a set of plates 17 in3balled between the separating partition 1_ and tiae -liall of tLe cylindrical sewage circulatiri--- chamber 1. Tt,,e plates 17 are inclined to the horizontal plane at 60 0 and the side edges of tiae plates 17 are in ti,Lt contact, res.ectively, with the valls of tae sewa,---e circu1_-tinF- chamber 1 and with the se-a ratin6 partition 13 vvdile the uper and lower edges of the plates 17 (FiL-,. 2) are arranged radially at the same dizzances from one arnoti-ier around the circumference o--" the cylindrical sewage-circulatin-_ chamber 1. Installed in the gaps between the plates 17 are additional plates 18 one side edge of;ihLica adjoins tae wall of tiie cy-_ lindrical sewa--e-circulatin,_ chamber 1, said plates beinf' arranted similarly to plates 17. One mo-ce,.rou3 of parti tion,6 for settlini of solid particles is arraned alon; 0 the heiGat of t..Le conical bottom 2 1). T.Lis group is constituted by conical sJaells 19 installed one after anotier alons the height of tLe conical bottom 2 with. a gap 20 relative to said conical bottom 2. The generatinp_ lines of the conical surfaces of said s.aells 19 are inclined to tiaeir axes of revolution at an angle whica is equal, essentially, to the inclination angle of the generating line of the conical surface of the conical 0 bottom 2 and may range from 45 to 60 ', The adjacent conical shells 19 overlap one another partly and are installed re.,,iotely from one another at these overlapping portions. The conical shells 19 rest on ribs 21 secured to the conical bottom 2.

The apparatus for clarficiation of industrial sewage also comprises a pressuretight bell-shaped hous- inj 22 located, essentially, above the sewage-circulatin:- chamber 1, the lower edge of said housing being lo- w C> cated below the upper edge of the separating partition 13 inside the cylindrical chamber 1 and encompasses said upper ege of said separatinS partition 13. The bell- shaped housing 22 has a branch pipe 23 connecting it with the air rarefaction means 24. This means may be constituted by any known device capable of ensurinj a rarefaction of 0.07 - 0.03 PAPa inside the bell- shaped housing 22. In the embodiment described herein the air-rarefaction means 24 is constituted by a fan.

Secured outside of the cylindrical sewage-airculatinS chamber 1, in its lower portion, essentially at its joint with the conical bottom 2 is a circular header 25 which communicates through slots 26 equispaced around the perimeter of the lower edge of the cylindrical sewage-circulating chamber 1 with the gap-20 between the conical shells 19 and the conical bottom 2, and - 15 with the bell-shaped housing 22.

The circular header 25 communicates with the bellshaped housing 22 by a group of hoses 27 located outside of the cylindrical sewa7e-circulating chamber 1, C connected with the pressaretight bell-shaped housing 22 at one end and, with the circular header 25 at the other.

The branch pipe 7 for feeding the polluted industrial sewage is connected via the adapter 28 with tne pipeline 29 for transportation of polluted sewaje.

Each hose 27 has a horizontal section 30 (Fig.3) located i=ediately above the level of the upper edge 10 of the cylindrical sewage-circulating chamber 1. The horizontal section 30 of each hose 27 is cc-n-nected with the vertical section 31 Of stLid 'nose 27 by a de- tachable coupling 32 (Figs 4,5) with a gasket 33 of an elastic material, e.g. rubber, which ensures pressuretight connection of the horizontal and vertical sections 30 and 31. 20 Shoyrn by arrows in Figs 193 is the direction of movement of industrial water in the course of its purification and the direction of motion of solid particles. The disclosed apparatus for clarification of industrial sewage functions as follows. The cylindrical sewage-circulating chamber 1 16 - (Fig. 1) is filled with polluted industrial water containing a hignl.-- molecular flocculant whose amount usually ranges from 3 to 6 g/m 3 of polluted industrial water. The polluted industrial water with a flocculant is delivered under pressure through adapter 23 into the branch pipe 7 for feeding the polluted industrial water and is directed upward inside the cylindrical separating partition 12 along the axis 0 of the chamber 1.

onen the water level in the cylindrical chamber 1 1 approaches the upper edge 10 of said chamber 1 located above the lower edge of the bell-shaped housing 22, the air rarefaction means 24, e.g. a fan, is turned on thus building up a vacuixn riside the pressuretight Co) bell-shaped housing 22, the value of this vacuum reaching 0.07 - 0.08 1. 2a.

In the course of filling the cylindrical sewagecirculating chamber 1, the polluted industrial sewage W starts to be purified. The movement of the flow of pol- luted water inside the separating partitions 12 and 13 in the central part of the chamber 1 is of turbulent nature at which the polluted water is intensively mixed with the flocculant. Passing inside the separating partitions 12 and 13, the polluted industrial sewage flows through holes 14 and 15 and is distributed uniformly over the volume of the chamber 1 so that the turbulence 17 - of the flow diminishes and the flow of industrial water outside of the separating partition 13 in the peripheral part of the chamber 1 has a laminar nature thus conducing to quiet precipitation of solid particles on the plates 17, 1S and to their further movement to the slurry- discharGing branch pipe 6.

1jeanwhile the level of industrial water inside the partitions 12, 13 is higher than the level in the perLpheral portion of the chamber 1 outside the parti10 tion 13. This level is the hi7.hest inside the central c > separating partition 12. The difference of levels depends on the ratio of diameters of partitions 12, 13 and diameters of holes 14, 15 in said partitions 12, 13. By the moment when the cylindrical lating chamber 1 is filled up to its upper edge 10 the surface layer of water up to 0.3 m thick in the peripheral portion of the chamber 1 is purified to the required degree of cleanness and is drained over the upper edge 10 into the circular trough 9 for the discharge of purified water. The water level in the central part of the chamber 1 inside the pressuretight housing 22 rises to 0.5 m due to rarefaction of air inside it. The gas and air bubbles are intensively liberated from the surface of industrial water in the pressuretight bell-shaped housing 22 and the degree of degassing of the polluted industrial water C1 13 - depends substantially on the area of the surface from which gas is liberated.

The bulk of polluted industrial water enters from the pressuretight nousin; 22 through hoses 27 into the c> circular header 25 from which it flows through slots 26 into the gap 20 located between the conical shells 19 and the conical bottom 2 wherefrom it flows through gaps between the shells 19 into the conical bottom 2 of the industrial sewage-circulating chamber 1. The same botto-n receives part of the polluted industrial sewage with flocculant coming out through the gaps between cylindrical shells 10 from the polluted water delivery zone defined by the separating partition 13 The remaining part of polluted sewage with flocculant enters the sewage purification zone through holes 14, 15 of the separatinj partitions 12, 13.

Degassin,,-; of the polluted industrial sewage containing flocculant is effected when sewage passes inside the partition 12 in the polluted water delivery zone and during its passage through the horizontal seetions 30 (Fig. 3) of the hoses 27. Degassing intensifies to air-rarefaction inside the housing 22 and the hoses 27 connected to it.-As a result, the polluted sewage with flocculant enters the sewage purification zone practically having no gas-air phase, thus conducing to formation of compacted floccules which are capable of rapid precipitation and ruling out the floc- cular flotation of suspended solid particles which,in the final analysis, improves capacity of the apparatus and the quality of purification of industrial sewage.

Clarification of industrial sewage occurs when it passes through the purification zone,namely throu6h the gaps between the plates 17 (Fig. 2) and 18 which are used for settlin- of the solid particles. The cla- C) rified industrial sewage overflows the upper edge 10 (Fic;. 1) of the sewage-circulating chamber 1 into the circ-ular troug1a 9 a-ad leaves the apparatus throu6h the purified water oullet branch pipe 11. The solid particles in the form of floccules move over the plates 17 and 13 under gravity and enter the lower part of the sewagecirculating chamber 1. The polluted industrial sewage is still better purified due to its filtration through the layer of flocculated slurry descedning from the plates 17 and 18 onto the conical shells 19 located in close proximity to the conical bottom 2. Concurrently, the flattened jets of polluted industrial sewage es- caping from of the gaps between the cylindrical shells 16 destroy the three-dimensional structure of flocculated slurries and carry them towards the slurry-collecting pocket 5 from which the slurry is removed from the apparatus through the slurry-discharging branch pipe 6.

Claims (3)

CLAI1JS:

1. An apparatus for clarification of industrial sewage wherein the cylindrical chamber for circulation of sewage to be purified is installed vertically, secured to the conical bottom of the sewage-circulating chamber are a branch pipe for feeding polluted industrial water with flocculants, the outlet hole of said branch pipe being arranged along the axis of the sewage- t;> circulating chamber, and a branch pipe for discharging W the slurry; a circular trough secured outside of the cylindrical sewage-circulating chamber, at its upper edge, serves for the drainage of purified industrial sei,,Tage; accommodated inside the cylindrical sewagecirculating chamber are partitions for settling the solid particles, the surfaces of said partitions being inclined towards the axis of the cylindrical sewagecirculating chamber; installed along the axis of the cylindrical sewage-circulating chamber, in its central part, is at least one separating partition with noles for distributing the polluted industrial sewage over the volume of the cylindrical sewage-circulating chamber, the upper edge of said separating partition bein.--- arranged, essentially, level with the upper edge of the cylindrical sewage-circulating chamber; installed above the separating partition is a pressuretight bell-shaped housing whose lower edge is arranged below the upper edge of the separating partition inside the cylindrical sewage- circulating chamber; the pressuretight bell-shaped housing is in communication with an air-rarefaction means.

2. An apparatus for clarification of industrial sewage according to Claim 1 wherein partitions for settling of solid particles are made in the form of coaxial conical shells installed one after another along the height of the conical bottom with gaps relative to its walls; arranged outside of the cylindrical sewagecirculating chamber, in its lower part, is a circular header communicating with the gap between the conical slaells and the conical bottom; a group of hoses arranged outside the cylindrical sewage-ci.re.7.3..ating chamber communicates with the pressuretight bell-shaped housing at one end and with the circular header at the other.

3. An apparatus for clarification of industrial sewage realized as described above with reference to E> the accompanying drawings