US2901113A - Apparatus for removing solids from a flowing stream of liquid - Google Patents

Description

Aug. 25, 1959 'E. c. NEWELL 2,901,113

APPARATUS FOR REMOVING SOLIDS FROM A FLOWING STREAM OF LIQUID Filed Aug 27, 1957 3 Sheets-Sheet 1 Aug. 25, 1959 E. c. NEWELL 2,901,113

APPARATUS FOR REMOVING SOLIDS FROM A FLOWING STREAM OF LIQUID Filed Aug. 27, 1957 3 Sheets-Sheet 2 1959 E. c NEWELL 2,901,113

ARPARATUS FOR REMOVING SOLIDS FROM A FLOWING STREAM OF LIQUID Filed Aug. 27, 1957 3 Sheets-Sheet 3 United States APPARATUS FOR REMUVING SOLIDS FROM A FLOWING STREAM OF LIQUID Application August 27, 1957, Serial No. 680,539

9 Claims. (Cl. 210-158) This invention relates to new and useful improvements in apparatus for removing from a flowing stream of liquid, and transporting in a dewatered condition to a single point of disposal, suspended, and a proportionately excessive amount of floating, solids by a combined skiinming, screening and conveying operation.

The primary object of the present invention is to provide apparatus for performing the combined functions of skimming a major portion of the floating solids from the surface of a stream of liquid, screening out the suspended solids and the remaining floating solids from the stream, cleaning the accumulated solids from the surface of the screen, and transporting, to a point of disposal, through a single dewatering and conveying mechanism, the total mass of solids removed from the stream.

A further object of this invention is to provide apparatus of the foregoing character wherein a common trough is employed in performing both the skimming and the conveying operations.

A still further object of the invention is to employ hydraulic means for removing the accumulated solids from the screen, and for skimmingthe major portion of the floating solids from the stream, into said common trough.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same:

Figure 1 is a top plan view of a device embodying the present invention shown as employed in a typical installation,

Figure 2 is a vertical sectional view, taken on the line 2'-2 of Fig. 1, and

Figure 3 is a sectional view taken on the line 3--3 of Fig. 1.

In the drawings, wherein-for the purpose of illustration is shown a preferred embodiment of this invention,

' there is shown a portion of a concrete channel 11, formed by two vertical side walls 12 and a flat bottom 13, which carries a stream of liquid 14 moving in the direction indicated by the arrows of Figs. 1 and 3. It is to be understood that the stream is made up of water, sewage, industrial waste, or any other liquid likely to contain suspended or floating solid particles, or both.

In the rear part of the channel portion illustrated, a dam 15, extending between the side walls 12 and contiguous with the bottom 13, is formed. Connected to the top part of the dam 15 is a vertically adjustable weir plate 16 which controlsthe water level through the screen.

A device embodying the present invention, designated generally by the reference character 18, is installed in the channel ahead of the dam 15. This device serves the purpose of removing particles of solid material carried by. the stream 14 in order to prevent such particles from clogging or otherwise injuring subsequent equipment using or handling the stream liquid, or in order to prevent the presence of such solids from giving rise to an aren't into it with the result that, despite its movement, the

re r objectionable and unsanitary condition when the stream is discharged into a natural waterway.

The device 18 includes a screen cloth or other screen member movable in a closed path extending above and below the surface 17 for removing suspended solid particles from the stream and placed in the channel in such a fashion that the entire flow of the stream is confined to it. Furthermore, the screen member is continuous along its entire path of movement so that as portions of it are lifted from the stream other portions are entered entire flow of the stream is continuously intercepted by some portion of the screen member. In the present embodiment, the screen structure is provided in the form of a screen disc assembly 19 mounted for rotation in a vertical plane normal to the fiow of the stream with a bottom segment 20 submerged in the liquid and with a remaining top segment 21 extending above the surface.

The disc 19 comprises a hoop like frame 22 having a periphery formed by a circular channel member 23, the

, flanges of which are directed inwardly towards the center of the disc.

Radial members 24, angularly spaced, connect the circular member 23 to a hub portion 25. Preferably, the members 24 are also channel members disposed with their flanges parallel to the plane of rotation and leading forward in the direction of rotation of the disc. The forward edge of the member 23 is provided with a forwardly extending flange 26 which serves a purpose hereinafter described.

A screen cloth 27, which extends across the entire face of the disc 19, is mounted in back of the radial members 24. Behind the screen 27, additional frame structure, comprising a plurality of radial spoke members 28, each angularly aligned with one of the radial members 24, and cross members 29 radially spaced from the hub portion 25 and connecting adjacent spoke members 28, is provided. The members 29 increase the rigidity of the frame structure and provide a backing for the screen cloth 27.

The screen disc assembly 19 is supported by a shaft 30 extending rearwardly from the hub portion 25 of the disc and journaled in two pillow block bearings 31 mounted on spaced I beams 32 which extend transversely across the channel 11 and rest on shelves 33 formed on the walls 12. Rotation of the disc is effected by a suitable drive motor 34 and speed reducing mechanism 35 mounted on one of the side walls 12. A drive chain 36, trained over a sprocket 37 fixed to the shaft 3% and over the output sprocket 38 of the speed reducer, provides a driving connection between the shaft 30 and the speed reducer 35.

Immediately ahead of the screen disc 19 the channel 11 is provided with a wall 39 which extends across the channel and has an arcuately shaped top surface 4&1 corresponding to the curvature of the circular member 23 forming the periphery of the screen disc. A flexible sealing member 41, of rubber or the like material, is connected to the wall 39 by a curved angle member 42 so as to extend rearwardly from the top surface 40 into sealing engagement with the inner surface of the flange 26. It will be seen that this arrangement prevents the passage of liquid or solids around the outer edge of the disc and thus confines the entire flow to the screen cloth.

An elongated skimming trough 43 for removing floating solids from the surface 17 is partially submerged in the top portion of the stream 14 ahead of the screen disc 19 with its longitudinal axis horizontal and normal to the flow of the stream. Referring to Figs. 1 and 2, it is seen that the trough as spans the side walls 12 of the channel 11 and has an upstream portion or forward wall 44- provided wtih a top edge 45 lying parallel with and spaced slightly below the liquid surface 17 so as to allow floating solids carried along by the current of the stream to pass over the wall 44 and to enter the trough. The rear wall 46 of the trough extends above the surface so that, the solids; are retained in the troughonce they have gained entry.

To. assist solids in entering the trough, the forward wall 44 is provided with. a forwardly depending lip 47 formed along the edge 45. Also, ahead of the trough 43 there is provided a liquid supply pipe 48 having an end portion 49 positioned above the surface 17 parallel with the longitudinal axis of the trough 43 and provided with. spaced outlet nozzles 50. The nozzles 50 are directed towards the trough 43 and downwardly towards the. surface 17 so that when liquid under pressure is supplied to the pipe 43 a liquid spray plays against the surface, of theliquid and aids in moving, floating solids upv the lip 47 and into the trough 43.

Considering next the removal, of the solid particles from the device 18, it will be understod that suspended solid particles in the flow accumulate on the submerged portion of the screen cloth 27 and are subsequently elevated above the surface 17 by the rotative movement of the disc. Screenings which happen to fall from the surfa e of the, screen cloth are carried upwardly by the radial members 24 which, because of their channel shape, act as retaining troughs for such fallen screenings. Hydraulic means for removing the elevated screenings. from the cloth 2 7 and from the members 24 are provided behind the screen disc 19. In the present instance, this means comprises. a liquid supply pipe 51 having an end portion 52 positioned in spaced radial relationship with the disc and having spaced outlet nozzles 53 connected to the pipe portion 52'. These nozzles form a jet or spray of liquid directed against the back of the screen cloth 27 when liquid under pressure is supplied to the pipe. The spray thus formed flushes the screenings from the screen cloth and carries them forward beyond the surface of the. disc to the skimming trough 43. A valve 53a in the pipe 51 permits control of the pressure in the pipe portion 52 and, consequently, allows the force of the spray formed by the nozzles to be readily adjusted in order to, obtain a. spray best suited to the operating conditions.

In order to keep the cleaning spray and the screenings carried thereby which fall short of the trugh 43 from reentering the flow stream 14, the rear wall 46 of the trough is provided with an upwardly and rearwardly sloped member 54' formed along that portion of its top edge which lies. in. front of the nozzles 53, as shown: best in Fig. 3. The rear edge 55 of the member 54 is closley spaced in relationship to the disc 1-9. Thus, it will be seen, the member 54: serves as a drain board which channels the spray and the screen.

ings falling short of the trough into the top of the trough;

A vertical splash plate 56 is mounted above the forward edge of the trough in front of the nozzles 53- to keep the spray and the screenings carried thereby from traveling forward beyond the skimming trough. As shown in Fig. 2, the plate 56 may be bolted to a channel member 57 placed across the channel 11 above the surface 17 in parallel relationship with the forward. wall 44 of the trough.

The solids in the skimming trough, which include both the solids skimmed from the surface 17 and the suspended solids washed from the screen disc, are removed by conveyor means cooperating with the skim The conveying means cooperating with the skimming trough is shown to take the form of an endless chain 60 carrying a plurality of spaced flights 61 in movement through the skimming trough and the elevating trough. The endless chain 60 moves in a path defined by idler sprockets 63, 64 and 65 and drive sprocket 66. The sprockets 63 and 64 are positioned above the opposite ends of the skimming trough and serve to. guide the flights 61 through the skimming troughinconveying relationship. with the solid particles therein. The drive; sprocket 66 is connected to the upper end of the second trough 58 and together with the idler sprocket 64 guides the flights 61 through the elevating trough 58 in conveying relationship with the solid particles therein. The idler sprocket 65 connected to the frame structure 67 serves to support the return portion of the chain. Preferably, the flights 61 are perforated, as shown, so that the liquid will drain from the solids as the flights. are moved through the troughs.

The chain 60 is driven by drive means. such as a, drive motor 68 and associated speed reducer 69 mounted. on the frame structure 67. A chain 70 trained over the, output shaft 71 of the speed. reducer and a: sprocket. 72. fixed to the shaft 73. of the drive sprocket 66 transmits the driving force of the motor to the drive sprocket.

The operation of the present device may be briefly summarized as follows: As the flow 14 passes through the screen disc 19, the screen cloth 27 intercepts and retains solids suspended in the flow. A liquid spray formed by the spray nozzles 53 flushes the accumulated. solids, which are elevated from the surface of the liquid, by rotation of the screen disc, from the screen cloth and carries them to the skimming trough 43. Simultaneous with the screening operation floating solids. are. carried into the skimming trough by the fluid current; with the assistance of a liquid spray formedv by the 1101 zles 50. Both classes of solids are then removed from the skimming trough by the conveyor flights 61 to the auxiliary conveyor 62, these solids being dewatered bythe action of the flight perforations as they are carried up the second trough 58.

It is to be understood that the form of this invention herewith shown and described is to be taken as. a preferred example. of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the in:- vention or the scope of the subjoined claims.

Having thus. described the invention, I claim l. A device for removing solids from a liquid; stream, comprising a screen member movable in a closed path extending above and below the surface of the stream for removing suspended, solidsfrom said stream, means for driving said member along said path, an elongated; skimming. trough partially submerged in the. top portion of said: stream ahead of said screen member, said. trough. having an. upstreamv portion defining atop edge. disposedv transversely of said stream and spaced. slightly below the surface. thereof to allow floating solids carried by; the. stream to pass. over said upstream portion and enter said. trough, cleaning means above the surface of the stream for removing from. said screen member the solids accumulated thereon and: for carrying such solids to said. trough, and means for. removing from said trough the combined. mass of solids contained therein.

2. A device for removing solids from a. liquid stream, comprising a screen cloth. movable in a closed. path. extending above and below the surface of the stream for removing suspended solids from said. stream, means for driving saidcloth along said path, an elongated skimming; trough partially submerged in the top portion of said stream ahead of said screen. cloth, said trough having an. upstream portion defining a topedge disposedtran'sversely of said stream and: spaced. slightly below the surface. thereof to allow floating solids carried by the stream. to.

means-above the surface of the stream for forming a spray of liquid directed against the back of said cloth to flush from said cloth the solids accumulated thereon and to carry such solids forward to said skimming trough, and means for removing from said trough the combined mass of solids contained therein.

3. A device for removing solids from a liquid stream, comprising a screen cloth movable in a closed path extending above and below the surface of the stream for removing suspended solids from said stream, means for driving said cloth along said path, an elongated skimming trough partially submerged in the top portion of said stream ahead of said screen cloth, said trough having an upstream portion defining a top edge disposed transversely of said stream and spaced slightly below the surface thereof to allow floating solids carried by the stream to pass over said upstream portion and enter said trough, means above the surface of the stream for forming a spray of liquid directed against the back of said cloth to flush from said cloth the solids accumulated thereon and to carry such solids forward to said skimming trough, a splash plate mounted above the forward side of said trough to keep said jet of liquid and the solids carried thereby from passing beyond said trough, and means for removing from said trough the combined mass of solids therein.

4. A device for removing solids from a liquid stream, comprising a screen cloth movable in a closed path extending above and below the surface of the stream for removing suspended solids from said stream, means for driving said cloth along said path, an elongated skimming trough partially submerged in the top portion of said stream ahead of said screen cloth, said trough having an upstream portion defining a top edge disposed transversely of said stream and spaced slightly below the surface thereof to allow floating solids carried by the .stream to pass over said upstream portion and enter said trough, means above the surface of the stream for forming a spray of liquid directed against the back of said cloth to flush from said cloth the solids accumulated thereon and to carry such solids forward to said skimming trough, a second trough connected end to end to one end of said skimming trough and leading from the latter to a discharge point located above and to one side of the stream, an endless chain carrying a plurality of spaced flights in movement through said skimming trough and said second trough for effecting the conveyance of solids along the length of said troughs to said point of discharge, and means for driving said chain.

5. A device for removing solids from a stream of liquid, comprising a screen disc mounted for rotation in a vertical plane normal to the flow of said stream for removing solids suspended in said stream, said disc having a bottom segment submerged in said stream and a remaining top segment extending above the surface of the same, driving means for rotating said disc, an opentopped elongated skimming trough partially submerged in the top portion of said stream ahead of said disc, said trough having an upstream portion defining a top edge disposed transversely of said stream and spaced slightly below the surface thereof to allow floating solids carried by the stream to pass over said upstream portion and enter said trough, means for forming a liquid spray directed against the back of said top segment for flushing accumulated solids from said top segment and for carrying such solids forwardly from the surface of said disc to said skimming trough, and means for removing from said skimming trough the combined mass of solids contained therein.

6. A device for removing solids from a stream of liquid, comprising'a screen disc mounted for rotation in a vertical plane normal to the flow of said stream for removing solids suspended in said stream, said disc having a bottom segment submerged in said stream and a remaining top segment extending above the surface of the same, driving means for rotating said screen disc, an open-topped elongated skimming trough partially submerged in the top portion of said stream ahead of said disc with its longitudinal axis horizontal and normal to the flow of said stream, said trough having a forward wall provided with a top edge lying slightly below the surface of said stream so as to allow floating solids carried along by the'current of said stream to pass over said forward wall and enter said trough, said trough also having a rear wall projecting above the surface of said flow so as to retain said floating solids in said trough once they have gained entry, means for forming a liquid spray directed against the back of said top segment for flushing accumulated solids from said top segment and for carrying such solids forwardly from the surface of said disc to said skimming trough, a flight conveyor movable longitudinally of said trough for effecting the removal of the combined mass of solids in said trough, and means for driving said conveyor.

7. A device as defined in claim 6 further characterized by a forwardly depending lip formed along said top edge of said trough, and means for forming a liquid spray ahead of said trough directed downwardly and forwardly against the surface of said stream so as to assist said floating solids in passing over said lip and said top edge and into said trough.

8. A device as defined in claim 6 further characterized by a second trough connected end to end to one end of said skimming trough and leading from said skimming trough to a discharge point located above and to one side of said stream, and by said flight conveyor comprising an endless chain carrying a plurality of spaced flights in movement through said skimming trough and said second trough for effecting the conveyance of solids along the length of said troughs to said point of discharge, and means for driving said chain.

9. A device for removing solids from a stream of liquid comprising a screen disc mounted for rotation in a vertical plane normal to the flow of said stream for removing suspended solids therefrom, said disc including a hoop-like frame and a screen cloth mounted across the face of said frame and being positioned so as to have a bottom segment submerged in the stream and a remaining top segment extending above the surface of the same, driving means for rotating said disc, an open-topped elongated skimming trough partially submerged in the top portion of said stream ahead of said disc with its longitudinal axis horizontal and normal to the flow of said stream and having a forward wall provided with a longitudinally extending top edge lying slightly below the surface of said flow so as to allow floating solids carried along by the current of said stream to pass over said forward wall and into said trough, said trough also having a rear wall projecting above the surface of said stream so as to retain said floating solids in said trough once they have gained entry, a forwardly depending lip formed along said top edge, means for forming a liquid spray ahead of said trough directed downwardly and rearwardly against the surface of said stream so as to assist said floating solids in passing over said lip and said top edge and into said trough, means for forming a second liquid spray directed against the back of said top segment for flushing accumulated solids from said top segment and for carrying such solids forwardly from the surface of said disc to said skimming trough, a splash plate mounted above said forward wall for preventing said second liquid spray and the solids carried thereby from traveling forward beyond said trough, a drainboard formed along a portion of said rear wall extending upwardly into close proximity with said disc for channeling such liquid spray and solids as fall short of said trough into said trough, a second trough connected end to end to one end of said skimming trough and leading from said skimming trough to a discharge point located above and to one side of said stream, an endless chain carrying moans Z a plurality of spaced flights: in movement through saiti skimming trough 3,1111 said second; trough foneifecting the conveyance. of solids. along the length of said troughs to said point of discharge, and means; for driving said chain.

References Cited in the file Qfi his; pate t UNITED STATES PATENTS 2,237 172 Briggs V Apr. 1-, 1941

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