CA1065765A - Sludge removal system and settling tank combination - Google Patents
Sludge removal system and settling tank combinationInfo
- Publication number
- CA1065765A CA1065765A CA233,284A CA233284A CA1065765A CA 1065765 A CA1065765 A CA 1065765A CA 233284 A CA233284 A CA 233284A CA 1065765 A CA1065765 A CA 1065765A
- Authority
- CA
- Canada
- Prior art keywords
- tank
- pipe
- sludge
- suction
- bridge
- 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.)
- Expired
Links
Classifications
-
- 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
- B01D21/04—Settling tanks with single outlets for the separated liquid with moving scrapers
-
- 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
- B01D21/0006—Settling tanks provided with means for cleaning and maintenance
-
- 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
- B01D21/04—Settling tanks with single outlets for the separated liquid with moving scrapers
- B01D21/06—Settling tanks with single outlets for the separated liquid with moving scrapers with rotating scrapers
-
- 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
-
- 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
- B01D21/2466—Mammoth pumps, e.g. air lift pumps
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Jet Pumps And Other Pumps (AREA)
- Filtration Of Liquid (AREA)
- Refuse Collection And Transfer (AREA)
- Treatment Of Sludge (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE :
Sludge removal system in combination with a sludge settling tank to remove sludge which settled out at the bottom of the tank comprising a support bridge located above the tank and movable in a path over the tank; means removing the sludge from the bottom of the tank, as the bridge is moving while excluding access of air at ambient pressure to said sludge and forming an hydraulically closed suction fluid conduit to remove said sludge, including a suction nozzle and a suction riser pipe supported from the bridge and extending into the tank to sweep the bottom of the tank upon movement of the bridge in its path; a fixed sludge removal pipe located at least in part below the bottom of the tank, fixed with respect to the tank, immovably secured thereto and having a vertically extending fixed pipe portion;
a connecting pipe means supported from and moving with the bridge including a horizontal portion located above the highest liquid level joined to the suction riser pipe and an end portion extending vertically downwardly, and aligned with the vertically extending portion of the fixed sludge removal pipe;
and a movable joint which is substantially liquid-tight and tight with respect to subatmospheric pressure connecting the vertical end portion of the connecting pipe means and the sludge removal pipe; and a pump located laterally with respect to the tank and having a suction inlet connection connected to the sludge removal pipe, and hence to the hydraulically closed fluid conduit to provide a suction fluid circuit which is hydraulic-ally closed from the nozzle below the liquid level through the pipe portion above the liquid level and then to the laterally located pump while permitting relative movement of the nozzle in its path over the sludge settling tank. And, a method for removing sludge from the bottom of a settling tank.
Sludge removal system in combination with a sludge settling tank to remove sludge which settled out at the bottom of the tank comprising a support bridge located above the tank and movable in a path over the tank; means removing the sludge from the bottom of the tank, as the bridge is moving while excluding access of air at ambient pressure to said sludge and forming an hydraulically closed suction fluid conduit to remove said sludge, including a suction nozzle and a suction riser pipe supported from the bridge and extending into the tank to sweep the bottom of the tank upon movement of the bridge in its path; a fixed sludge removal pipe located at least in part below the bottom of the tank, fixed with respect to the tank, immovably secured thereto and having a vertically extending fixed pipe portion;
a connecting pipe means supported from and moving with the bridge including a horizontal portion located above the highest liquid level joined to the suction riser pipe and an end portion extending vertically downwardly, and aligned with the vertically extending portion of the fixed sludge removal pipe;
and a movable joint which is substantially liquid-tight and tight with respect to subatmospheric pressure connecting the vertical end portion of the connecting pipe means and the sludge removal pipe; and a pump located laterally with respect to the tank and having a suction inlet connection connected to the sludge removal pipe, and hence to the hydraulically closed fluid conduit to provide a suction fluid circuit which is hydraulic-ally closed from the nozzle below the liquid level through the pipe portion above the liquid level and then to the laterally located pump while permitting relative movement of the nozzle in its path over the sludge settling tank. And, a method for removing sludge from the bottom of a settling tank.
Description
1065'765 The present invention relates to a sludge removal system in combination with a sludge settling tank to remove sludge which settled out at the bottom of the tank, particularly a biolo-gical settling basin, and to a method of removing sludge from the bottom of the settling tank.
Sewage, which has solids suspended therefrom, is cus-tomarily introduced into a basin, in which the solids can settle out. A sludge forms at the bottom of the basin wnich can be re-moved by means of a suction apparatus, such as a suction nozzle, secured to a transport bridge located above the basin and arranged to travel over the basin to carry the nozzle along. The sludge or mud which has settled out from the sewage can then be removed over a pipe or duct arrangement connected to the suction nozzle.
Sewage treatment plants, and sludge settling tanks or basins, should be as simple as possible, so that, in operation, maintenance of the apparatus associated therewith is simplified.
It is particularly important that the mechanical arrangements should be as simple as possible, and that portion of the apparatus which is movable over the level of liquid in the tank or basin should preferably not have electrical apparatus thereon, so that cable or open-wire connections to the electrical apparatus carried on the movable bridge can be avoided. Preferably, electrical drives for all apparatus used in connection with such settling . tanks or basins should be fixed and located at non-movable posi-tions. To avoid a drive on the movable bridge, it has -~, . , , , , .. , : . . .
,, ; ,. .... -!. . : . . ,~, .
',`` . ' ~, ` . .. ". ~ ' ' ' ,' ' " ' , s .
, .. . . . . . .
previously been proposed to move the bridge itself by means of a cable drive, the cable itself being moved by a motor in fixed location. It has also been proposed to construct essentially circular basins, and to rotate the bridges by means of a mechanical drive located, for example,in the center of the basin, the bridge extending radially from a center support to the edge or rim thereof. Motor drives may, however, be required for the pumps to remove sludge and deposits through the nozzle. Such pumps, located on the bridge, are subject deterioration due to corrosion resulting from gases and vapors rising from the sewage in the settling tank. Movable electrical connections to pump apparatus at ~i the bridge are also subject to deterioration and require excessive maintenance. Mechanical pumps located on the bridge can be avoided by using syphons to remove the precipitated .j ;
solids from the bottom of the tank. The syphons are secured to the bridge to sweep across the bottom of the tank or ba~in and to remove the solids together with some liquid by introducing them into a duct or channel for further transport of the sludge, for example by means of a pump. Syphons introduce additional problems. Reliable operation of the , syphons can be ensured only if the suction nozzle or pick-up ;l element actua~y removing the sludge, and the ducts connected thereto, do not plug- up or clog. If necessary, counterflow should be possible to provide for back-flushing of the nozzle and connected pipes. Such counterflow can be obtained by .' ~~ -.
:', ' . . ' 1065~65 rais~ng the level of liquid in the removal duct above the level of liquid in the basin. Additional apparatus must, however, sti~ be used to remove air and gas from the liquid which is passed through the ducts or pipes, usually in form S of large bubbles. Such bubbles or gas contents greatly decrease the quantity of sludge and liquid being removed and may,at times, interrupt the liquid column within the syphon.
The vacuum in the syphon can be re-established by locating a v cuum pump in connection with the connecting ducting; such a vacuum pump must, however, again be located on the bridge, `` requiring yet another power supply thereto.
In some installations it is practically impossible to avoid deposits of solids in the suction nozzle and in the associated syphon ducts. It is practically impossible to prevent such deposits and re-establish flow by dropping the level in the collecting duct, or back-flushing the piping and the suction nozzle by raising the level in the collecting !~ duct over the level of the settling basin, since change in level of the collecting duct can be done only within a very limited range, and the initial difference in level between the liquid in the settling tank and the liquid in the ; collecting duct is small.
Some sewage disposal plants use a single settling tank only. In such plants, sewage is introduced into the : 25 settling tank with all its contaminants, which have not yet been removed by a prior pre-cleaning apparatus including "i'~ ,~
- . ~
mechanical cleaning systems such as rakes, or the like. The dan-ger of plugging or stoppages in the suction system is particularly high in single-stage installations. Back-flushing the suction nozzle and asqociated piping, to provide for self-cleaning, was possible only with additional apparatus.
It is an object of the present invention to provide a sludge removal system for combination with a settling tank which can be easily cleaned by back-flushing under high pressure, and which does not require motor drives on a movable bridge.
According to the present invention, there is provided a sludge removal system in combination with a sludge settling tank to remove sludge which settled out at the bottom of the tank com-prising a support bridge located above the tank and movable in a path over the tank; means removing the sludge from the bottom of the tank, as the bridge is moving while excluding access of air at ambient pressure to said sludge and forming an hydraulically clo-sed suction fluid conduit to remove said sludge, including a `~
suction nozzle and a suction riser pipe supported from the bridge and extending into the tank to sweep the bottom of the tank upon movement of the bridge in its path; a fixed sludge removal pipe located at least in part below the hottom of the tank, fixed with respect to the tank, immovably secured thereto and having a verti-cally extending fixed pipe portion; a connecting pipe means sup-ported from and moving with the bridge including a horizontal portion located above the highest liquid level joined to the suc-tion riser pipe and an end portion extending vertically down-wardly, and aligned with the vertically extending portion of the fixed sludge removal pipe; and a movable joint which is substan-tially liquid-tight and tight with respect to subatmospheric pressure connecting the vertical end portion of the connecting -~
pipe meanS and the sludge removal pipe; and a pump located later-ally wlth respect to the tank and having a suction inlet C
~.~ . . ..
. :...................... , .. . : ~
connection connected to the sludge re~ v~l pipe, and hence to the hydraulically closed fluid conduit to provide a suction fluid cir-cuit which is hydraulically closed from the nozzle below the liquid level through the pipe portion above the liquid level and then to the laterally located pump while permitting relative movement of the nozzle in itQ path over the sludge settling tank.
According to the present invention, there is also provided method to remove sludge from the bottom of a settling tank having a movable nozzle in fluid communication with the bot-tom of the tank, and a closed fluid piping conduit connected tothe movable nozzle including a fixed sludge removal pipe from which the sludge is discharged extending transversely of the tank and located below the tank, a movable riser extending from the movable nozzle to above the operating liquid level of the tank, a ' movable transverse connecting pipe located above the highest level of the tank and extending transversely of the tank, and an essen-) tially liquid-tight, suction-tight rotary joint connecting the movable transverse connecting pipe and a fixed downwardly exten-ding pipe jointed to said fixed transversely extending pipe to provide an eQsentially hydraulically completely suction-tigh~
closed fluid conduit from the nozzle to the terminal end of the transversely extending pipe, comprising the steps of moving the nozzle, and removing sludge from the bottom of the tank as the nozzle is moving while excluding access of air at ambient pressure to the sludge by applying suction to the transversely extending pipe in excess of the pressure head generated by the level of li-quid in the tank to apply the suction in the closed fluid conduit -as said nozzle is moving.
The invention will be described by way of example with reference to the accompanying drawings, wherein:
Fig. 1 is a schematic vertical sectional view through half of a circular settling basin with a radially located brJdge C
, ........... . . .
spanning the basin and having a central liquid-introducing struc-ture;
and Fig. 2 is a schematic piping diacram illustrat-ing selective sludge removal under forced flow conditions, or back-flushing also under forced flow conditions while providing single-direction pump operation.
A settling basin, generally shown at 1 in Fig. 1, has a circular outline when viewed from the top. An inlet struc-ture 2 is located centrally therein. Inlet structure 2 is a hollow col D 3 formed with openings 4 adjacent the bottom there-of. The basin 1 has an outer circular wall 5. An overflow trough 7 is secured to the outer wall 5 so that cleared liquid can be skimmed off the top level 6 and introduced into the clear-liquid trough 7, for removal from _ i !
.` ' . ' .' : , . ' . ' '. , ' ' ' .- :
106g765 the tank 5, trough 7 passing through a suitable opening (not shown) of the side wall 5 of the basin, or being in communication with a suction pump.
The upper edge or crown of wall 5 is s~tably shaped to guide rollers 9 supporting bridge 8 which extends radially from the center structure 2 across the basin. The bridge 8 is supported on center structure 2 by a hollow pipe-like cylindrical structure lO on which a gear ll is secured. Gear ll and, with it, cylindar~ 10 are guided by means of radial and axial or thrust-bearings (not shown) supported on~ a socket 12 and secured to spaced brackets ~ 13 which, in turn, are secured to cylinder 3. Rather than ;. using brackets, a support ring may also be usedj located, for example, at the inside of the hollow cylinder 3 of the inlet structure 2. Drive motor 15, secured to the inlet structure 2 and having a spur gear secured thereon in an engagement with gear 11, drives the bridge 9 in rotary movement about the basin 1.
~` Various other drive or support arrangements may be used; for example bridge 8 may be constructed as a cantilever-ed structure, freely extending across basin 1, 80 that further support, such as ro~ers 9 on the outer wall 5, is not necessary. The elements 11, 14, 15 drive bridge 8 over basin 1.
Two suction nozzles 17 are supported by means of riser ducts 18 from bridge 8. Suction nozzles 17 are .' ~, , .
,~ :
~. ~: - , . ~ - .
, . . . .
.. . . ~ . :
~065765 located to just clear the bottom of basin 1. They move along with the bridge 8. The risers 18 both terminate in a horizontal connecting line 19. Line 19 is located beneath bridge 8 to just clear the upper liquid level 6 of liquid in the basin 1. Connecting line 19 is suspended from bridge 8 by means of suspension holders 21. Preferably, a flow indicator, such asa transparent pipe section, or a deflecting vane with an external indicator, is located in the risers 18 at a readily visible position to indicate flow through the : 10 risers, which can be individually controlled by valves 22. .
The flow indicators are not shown in the drawings for . simplicity. - .
: Connecting line 19 extends horizontally, supported from bridge 8, and terminates at the center of rotation of ~ ~.
: 15 bridge 8 in a vertically downwardly extending end portion 23,having a terminal end 24. End 24 is flush with the end 25 . .
of a verticallyupwardly extending pipe 26 ~hich is fixed in position. The ends 24, 25 of pipes 19, 26 are thus movable with respect to each other and,to prevent leakage,they are covered by an external sleeva 27, engaging the respective . ~ .
pipe ends 24, 25 for example with o-rings. Connecting line 26 extends through the bottom of the inlet str~cture 2 of `................ the basin 1, and extends outwardly of the basin 1 to terminate i at a pumping station 28.
~, The joint formed by ends 24, 25 and collar or sleeve 27, forms a movable joint which connects the two pipes 19, 26 ~.. . -: . , - , , . -: ............. - : .
essentially liquid-tight, but permits free movement of the pipe elements 17, 18, 19, 23 with respect to the fixed pipe 26.
Line 26, which i9 used as the sludge removal pipe, is connected to the suction inlet of a pump 29 located in pump chamber 28.
The vertical part 30 of the sludge removal pipe 26 i8 coaxial with the center of rotation of bridge 8. It is surrounded by a wider pipe 31 forming the inlet for sewage to be cleared in the settling tank or basin. Pipe 31 merges at its upper end in a funnel-shaped enlargement 32. Pipe 31 extends through the bottom of the inlet structure 2 and is connected to a pipe duct 33 forming the inlet line for basin 1.
Operation: Sewage introduced through line 33 flows out of funnel 32, and through the center structure 2, to enter the basin 1 at the bottom openings 4. To remove sludge which has precipitated at the bottom of the basin 1, pump 29 is started. Pump 29 preferably has a variable, controllable through-put. Bridge 8 is started by starting motor 15. The entire bottom wall of basin 1 is thus continuously cleaned.
If the through-put through the pump changes substantially - which can be sensed, for example, by sensing pump-operating characteristics - or by observing flow through flow indicators or transparent pipe sections, pump 28 can be ..
,~
- - , ~ . . . . ..
80 operated that the sludge removal line 26 is used as a pressure or flushing or cleaning line. Interruption or substantial decrease of flow through the pump may be due to deposits at the nozzles or anywhere in the system of pipes 17, 18, 19, 23, 26. Referring to Fig. 2: Pipe 26 is connected to the inlet of pump 29 through a normally open inlet valve 34. The outlet from pump 29 is conducted to a sludge storage or further settling basin through a normally open outletvalve 33. The pump can be reverse-connected, however, by opening two normally closed valves 35, 36, connected between the outlet of valve 33 and the inlet of pump 29, and the outlet of pump 29 and the inlet to valve 34, -respectively. Under normal operating conditions, sludge will flow through pipe 26, as indicated in solid lines in Fig. 2, -through normally open valve 34, pump 29, and normally open valve 33. For reverse flushing, however, flushing liquid is introduced from the outlet pipe through the then opened normally closed valve 35, the suction inlet of pump 29 and the then opened normally closed valve 36 to flow as ~dicated in broken line arrows in reverse connection through the piping system 26, 23, 19, 18, 17. The through-put direction of the pump 29 remains the same regardless of the mode of operation - sludge removal or reverse flushing, as indicated ; by the fixed directional triangle within the pump symbol.
Pressurized cleaning or flushing liquid can thus be supplied both through the fixed as well as the movable portio~
;~, q ,~
~06576S
of the ducting system, to flush out any depo~its and to clear blockages. The flow indicator (not shown) within one of the pipes can be u~ed to determine the quantity or velocity of flow of flushing liquid through the respective risers 18. If the indicator should show that one of the lines does not receive its proper share of back-flushing liquid, then the other one of the lines can be shut off by means of valve 22, 80 that flushing liquid at full pumping pressure will be applied to the one line which is partly or wholly plugged,to clear that specific line of solids which caused the obstructi~n~ and stoppage. Since the direction of flushing flow is counter the removal direction, any stoppages are more readily cleared than the application of high-preæsure in flow direction. Persistent stoppages are effectively avoided. The pump permits back-flushing not only of the of fixed portion of the piping system, but also/the movable portion. The movable joint 27 is essentially tight, and permits application of pressurized fluid through the movable joint, thus ensuring reliable interruption-free operation.
In normal operation, however, the fixed, as well as the movable piping system, provide~ the connection to the suction inlet of the pump.
; Pwmping station 28 can be so arranged that the line26 operates as a syphon ter~ating in a pump sump in communication with the basin 1, from which solids removed from the basin can then be further transported or pumped.
`';. ~
;- . .. .... . . .............................. .
.. . .
~065765 An auxiliary pump i8 preferably provided in such arrangements as well, which permits back-flushing of the fixed as well as of the movable piping, as described in connection with pump 29.
The movable joint is so constructed that it is capable of accepting over-pressure (for pressurized back-flushing) as well as being tight with respect to under-pressure, that is, for normal, suction operation. Sealing the movable joint 27 with respect to under-pressure is facilitated by locating the movable joint 27 below the operating level 20 of the settling basin 1.
' The nwm~er of suction nozzles 17 depends largely on the size of the basin 1; depending on its size, one, or more ; of the ~uction nozzles can be used; two have been shown as an example. The suction nozzles are directly connected to a fixed suction line, preferably to the suction line directly connected to pump 29 without intermediate open vessels or troughs. Removal efficiency tnus is similar to that other-wise obtainable only with fixed nozzles. The arrangement, particularly as shown in Fig. 2, permits use of a single pump 29 which can be located essentially at random with respect to the operating level 20 of the liquid in the basin 1, and for example below the level of the basin 1, 80 that pressure will exist at the suction side of the pump, thus increasing the operating reliability of the system.
~/
~,. . . . . . .
. . - : ..
~6S76S
Inlet pipe 31 is located to surround the vertical portion 30 of the removal line 26. This permits symmetrical flow of the sewage introduced into the basin 1, and similarly essentially symmetrical distribution of the sewage S through the openings 4 into the basin 1.
The invention has been described with respect to a circular basin. The arrangement of the piping having a -~
movable, sealed joint between a fixed pipe part and a movable part effectively makes the suction nozzle 17 the suction opening for a fixed pumping station 28 located outside of the basin 1. In similar manner, a basin having a rectangular outline can be used; connection between the ixed and movable piping portions can then be obtained by telescoping pipes, for example, with the same advantages as those which are o ffl ainable with a circular basin as specifically described ; in connection with Fig. l.
: ~ .
Various changes and modifications may be made within the scope of the inventive concept.
'~
, ~. ~
,. ~
..
Sewage, which has solids suspended therefrom, is cus-tomarily introduced into a basin, in which the solids can settle out. A sludge forms at the bottom of the basin wnich can be re-moved by means of a suction apparatus, such as a suction nozzle, secured to a transport bridge located above the basin and arranged to travel over the basin to carry the nozzle along. The sludge or mud which has settled out from the sewage can then be removed over a pipe or duct arrangement connected to the suction nozzle.
Sewage treatment plants, and sludge settling tanks or basins, should be as simple as possible, so that, in operation, maintenance of the apparatus associated therewith is simplified.
It is particularly important that the mechanical arrangements should be as simple as possible, and that portion of the apparatus which is movable over the level of liquid in the tank or basin should preferably not have electrical apparatus thereon, so that cable or open-wire connections to the electrical apparatus carried on the movable bridge can be avoided. Preferably, electrical drives for all apparatus used in connection with such settling . tanks or basins should be fixed and located at non-movable posi-tions. To avoid a drive on the movable bridge, it has -~, . , , , , .. , : . . .
,, ; ,. .... -!. . : . . ,~, .
',`` . ' ~, ` . .. ". ~ ' ' ' ,' ' " ' , s .
, .. . . . . . .
previously been proposed to move the bridge itself by means of a cable drive, the cable itself being moved by a motor in fixed location. It has also been proposed to construct essentially circular basins, and to rotate the bridges by means of a mechanical drive located, for example,in the center of the basin, the bridge extending radially from a center support to the edge or rim thereof. Motor drives may, however, be required for the pumps to remove sludge and deposits through the nozzle. Such pumps, located on the bridge, are subject deterioration due to corrosion resulting from gases and vapors rising from the sewage in the settling tank. Movable electrical connections to pump apparatus at ~i the bridge are also subject to deterioration and require excessive maintenance. Mechanical pumps located on the bridge can be avoided by using syphons to remove the precipitated .j ;
solids from the bottom of the tank. The syphons are secured to the bridge to sweep across the bottom of the tank or ba~in and to remove the solids together with some liquid by introducing them into a duct or channel for further transport of the sludge, for example by means of a pump. Syphons introduce additional problems. Reliable operation of the , syphons can be ensured only if the suction nozzle or pick-up ;l element actua~y removing the sludge, and the ducts connected thereto, do not plug- up or clog. If necessary, counterflow should be possible to provide for back-flushing of the nozzle and connected pipes. Such counterflow can be obtained by .' ~~ -.
:', ' . . ' 1065~65 rais~ng the level of liquid in the removal duct above the level of liquid in the basin. Additional apparatus must, however, sti~ be used to remove air and gas from the liquid which is passed through the ducts or pipes, usually in form S of large bubbles. Such bubbles or gas contents greatly decrease the quantity of sludge and liquid being removed and may,at times, interrupt the liquid column within the syphon.
The vacuum in the syphon can be re-established by locating a v cuum pump in connection with the connecting ducting; such a vacuum pump must, however, again be located on the bridge, `` requiring yet another power supply thereto.
In some installations it is practically impossible to avoid deposits of solids in the suction nozzle and in the associated syphon ducts. It is practically impossible to prevent such deposits and re-establish flow by dropping the level in the collecting duct, or back-flushing the piping and the suction nozzle by raising the level in the collecting !~ duct over the level of the settling basin, since change in level of the collecting duct can be done only within a very limited range, and the initial difference in level between the liquid in the settling tank and the liquid in the ; collecting duct is small.
Some sewage disposal plants use a single settling tank only. In such plants, sewage is introduced into the : 25 settling tank with all its contaminants, which have not yet been removed by a prior pre-cleaning apparatus including "i'~ ,~
- . ~
mechanical cleaning systems such as rakes, or the like. The dan-ger of plugging or stoppages in the suction system is particularly high in single-stage installations. Back-flushing the suction nozzle and asqociated piping, to provide for self-cleaning, was possible only with additional apparatus.
It is an object of the present invention to provide a sludge removal system for combination with a settling tank which can be easily cleaned by back-flushing under high pressure, and which does not require motor drives on a movable bridge.
According to the present invention, there is provided a sludge removal system in combination with a sludge settling tank to remove sludge which settled out at the bottom of the tank com-prising a support bridge located above the tank and movable in a path over the tank; means removing the sludge from the bottom of the tank, as the bridge is moving while excluding access of air at ambient pressure to said sludge and forming an hydraulically clo-sed suction fluid conduit to remove said sludge, including a `~
suction nozzle and a suction riser pipe supported from the bridge and extending into the tank to sweep the bottom of the tank upon movement of the bridge in its path; a fixed sludge removal pipe located at least in part below the hottom of the tank, fixed with respect to the tank, immovably secured thereto and having a verti-cally extending fixed pipe portion; a connecting pipe means sup-ported from and moving with the bridge including a horizontal portion located above the highest liquid level joined to the suc-tion riser pipe and an end portion extending vertically down-wardly, and aligned with the vertically extending portion of the fixed sludge removal pipe; and a movable joint which is substan-tially liquid-tight and tight with respect to subatmospheric pressure connecting the vertical end portion of the connecting -~
pipe meanS and the sludge removal pipe; and a pump located later-ally wlth respect to the tank and having a suction inlet C
~.~ . . ..
. :...................... , .. . : ~
connection connected to the sludge re~ v~l pipe, and hence to the hydraulically closed fluid conduit to provide a suction fluid cir-cuit which is hydraulically closed from the nozzle below the liquid level through the pipe portion above the liquid level and then to the laterally located pump while permitting relative movement of the nozzle in itQ path over the sludge settling tank.
According to the present invention, there is also provided method to remove sludge from the bottom of a settling tank having a movable nozzle in fluid communication with the bot-tom of the tank, and a closed fluid piping conduit connected tothe movable nozzle including a fixed sludge removal pipe from which the sludge is discharged extending transversely of the tank and located below the tank, a movable riser extending from the movable nozzle to above the operating liquid level of the tank, a ' movable transverse connecting pipe located above the highest level of the tank and extending transversely of the tank, and an essen-) tially liquid-tight, suction-tight rotary joint connecting the movable transverse connecting pipe and a fixed downwardly exten-ding pipe jointed to said fixed transversely extending pipe to provide an eQsentially hydraulically completely suction-tigh~
closed fluid conduit from the nozzle to the terminal end of the transversely extending pipe, comprising the steps of moving the nozzle, and removing sludge from the bottom of the tank as the nozzle is moving while excluding access of air at ambient pressure to the sludge by applying suction to the transversely extending pipe in excess of the pressure head generated by the level of li-quid in the tank to apply the suction in the closed fluid conduit -as said nozzle is moving.
The invention will be described by way of example with reference to the accompanying drawings, wherein:
Fig. 1 is a schematic vertical sectional view through half of a circular settling basin with a radially located brJdge C
, ........... . . .
spanning the basin and having a central liquid-introducing struc-ture;
and Fig. 2 is a schematic piping diacram illustrat-ing selective sludge removal under forced flow conditions, or back-flushing also under forced flow conditions while providing single-direction pump operation.
A settling basin, generally shown at 1 in Fig. 1, has a circular outline when viewed from the top. An inlet struc-ture 2 is located centrally therein. Inlet structure 2 is a hollow col D 3 formed with openings 4 adjacent the bottom there-of. The basin 1 has an outer circular wall 5. An overflow trough 7 is secured to the outer wall 5 so that cleared liquid can be skimmed off the top level 6 and introduced into the clear-liquid trough 7, for removal from _ i !
.` ' . ' .' : , . ' . ' '. , ' ' ' .- :
106g765 the tank 5, trough 7 passing through a suitable opening (not shown) of the side wall 5 of the basin, or being in communication with a suction pump.
The upper edge or crown of wall 5 is s~tably shaped to guide rollers 9 supporting bridge 8 which extends radially from the center structure 2 across the basin. The bridge 8 is supported on center structure 2 by a hollow pipe-like cylindrical structure lO on which a gear ll is secured. Gear ll and, with it, cylindar~ 10 are guided by means of radial and axial or thrust-bearings (not shown) supported on~ a socket 12 and secured to spaced brackets ~ 13 which, in turn, are secured to cylinder 3. Rather than ;. using brackets, a support ring may also be usedj located, for example, at the inside of the hollow cylinder 3 of the inlet structure 2. Drive motor 15, secured to the inlet structure 2 and having a spur gear secured thereon in an engagement with gear 11, drives the bridge 9 in rotary movement about the basin 1.
~` Various other drive or support arrangements may be used; for example bridge 8 may be constructed as a cantilever-ed structure, freely extending across basin 1, 80 that further support, such as ro~ers 9 on the outer wall 5, is not necessary. The elements 11, 14, 15 drive bridge 8 over basin 1.
Two suction nozzles 17 are supported by means of riser ducts 18 from bridge 8. Suction nozzles 17 are .' ~, , .
,~ :
~. ~: - , . ~ - .
, . . . .
.. . . ~ . :
~065765 located to just clear the bottom of basin 1. They move along with the bridge 8. The risers 18 both terminate in a horizontal connecting line 19. Line 19 is located beneath bridge 8 to just clear the upper liquid level 6 of liquid in the basin 1. Connecting line 19 is suspended from bridge 8 by means of suspension holders 21. Preferably, a flow indicator, such asa transparent pipe section, or a deflecting vane with an external indicator, is located in the risers 18 at a readily visible position to indicate flow through the : 10 risers, which can be individually controlled by valves 22. .
The flow indicators are not shown in the drawings for . simplicity. - .
: Connecting line 19 extends horizontally, supported from bridge 8, and terminates at the center of rotation of ~ ~.
: 15 bridge 8 in a vertically downwardly extending end portion 23,having a terminal end 24. End 24 is flush with the end 25 . .
of a verticallyupwardly extending pipe 26 ~hich is fixed in position. The ends 24, 25 of pipes 19, 26 are thus movable with respect to each other and,to prevent leakage,they are covered by an external sleeva 27, engaging the respective . ~ .
pipe ends 24, 25 for example with o-rings. Connecting line 26 extends through the bottom of the inlet str~cture 2 of `................ the basin 1, and extends outwardly of the basin 1 to terminate i at a pumping station 28.
~, The joint formed by ends 24, 25 and collar or sleeve 27, forms a movable joint which connects the two pipes 19, 26 ~.. . -: . , - , , . -: ............. - : .
essentially liquid-tight, but permits free movement of the pipe elements 17, 18, 19, 23 with respect to the fixed pipe 26.
Line 26, which i9 used as the sludge removal pipe, is connected to the suction inlet of a pump 29 located in pump chamber 28.
The vertical part 30 of the sludge removal pipe 26 i8 coaxial with the center of rotation of bridge 8. It is surrounded by a wider pipe 31 forming the inlet for sewage to be cleared in the settling tank or basin. Pipe 31 merges at its upper end in a funnel-shaped enlargement 32. Pipe 31 extends through the bottom of the inlet structure 2 and is connected to a pipe duct 33 forming the inlet line for basin 1.
Operation: Sewage introduced through line 33 flows out of funnel 32, and through the center structure 2, to enter the basin 1 at the bottom openings 4. To remove sludge which has precipitated at the bottom of the basin 1, pump 29 is started. Pump 29 preferably has a variable, controllable through-put. Bridge 8 is started by starting motor 15. The entire bottom wall of basin 1 is thus continuously cleaned.
If the through-put through the pump changes substantially - which can be sensed, for example, by sensing pump-operating characteristics - or by observing flow through flow indicators or transparent pipe sections, pump 28 can be ..
,~
- - , ~ . . . . ..
80 operated that the sludge removal line 26 is used as a pressure or flushing or cleaning line. Interruption or substantial decrease of flow through the pump may be due to deposits at the nozzles or anywhere in the system of pipes 17, 18, 19, 23, 26. Referring to Fig. 2: Pipe 26 is connected to the inlet of pump 29 through a normally open inlet valve 34. The outlet from pump 29 is conducted to a sludge storage or further settling basin through a normally open outletvalve 33. The pump can be reverse-connected, however, by opening two normally closed valves 35, 36, connected between the outlet of valve 33 and the inlet of pump 29, and the outlet of pump 29 and the inlet to valve 34, -respectively. Under normal operating conditions, sludge will flow through pipe 26, as indicated in solid lines in Fig. 2, -through normally open valve 34, pump 29, and normally open valve 33. For reverse flushing, however, flushing liquid is introduced from the outlet pipe through the then opened normally closed valve 35, the suction inlet of pump 29 and the then opened normally closed valve 36 to flow as ~dicated in broken line arrows in reverse connection through the piping system 26, 23, 19, 18, 17. The through-put direction of the pump 29 remains the same regardless of the mode of operation - sludge removal or reverse flushing, as indicated ; by the fixed directional triangle within the pump symbol.
Pressurized cleaning or flushing liquid can thus be supplied both through the fixed as well as the movable portio~
;~, q ,~
~06576S
of the ducting system, to flush out any depo~its and to clear blockages. The flow indicator (not shown) within one of the pipes can be u~ed to determine the quantity or velocity of flow of flushing liquid through the respective risers 18. If the indicator should show that one of the lines does not receive its proper share of back-flushing liquid, then the other one of the lines can be shut off by means of valve 22, 80 that flushing liquid at full pumping pressure will be applied to the one line which is partly or wholly plugged,to clear that specific line of solids which caused the obstructi~n~ and stoppage. Since the direction of flushing flow is counter the removal direction, any stoppages are more readily cleared than the application of high-preæsure in flow direction. Persistent stoppages are effectively avoided. The pump permits back-flushing not only of the of fixed portion of the piping system, but also/the movable portion. The movable joint 27 is essentially tight, and permits application of pressurized fluid through the movable joint, thus ensuring reliable interruption-free operation.
In normal operation, however, the fixed, as well as the movable piping system, provide~ the connection to the suction inlet of the pump.
; Pwmping station 28 can be so arranged that the line26 operates as a syphon ter~ating in a pump sump in communication with the basin 1, from which solids removed from the basin can then be further transported or pumped.
`';. ~
;- . .. .... . . .............................. .
.. . .
~065765 An auxiliary pump i8 preferably provided in such arrangements as well, which permits back-flushing of the fixed as well as of the movable piping, as described in connection with pump 29.
The movable joint is so constructed that it is capable of accepting over-pressure (for pressurized back-flushing) as well as being tight with respect to under-pressure, that is, for normal, suction operation. Sealing the movable joint 27 with respect to under-pressure is facilitated by locating the movable joint 27 below the operating level 20 of the settling basin 1.
' The nwm~er of suction nozzles 17 depends largely on the size of the basin 1; depending on its size, one, or more ; of the ~uction nozzles can be used; two have been shown as an example. The suction nozzles are directly connected to a fixed suction line, preferably to the suction line directly connected to pump 29 without intermediate open vessels or troughs. Removal efficiency tnus is similar to that other-wise obtainable only with fixed nozzles. The arrangement, particularly as shown in Fig. 2, permits use of a single pump 29 which can be located essentially at random with respect to the operating level 20 of the liquid in the basin 1, and for example below the level of the basin 1, 80 that pressure will exist at the suction side of the pump, thus increasing the operating reliability of the system.
~/
~,. . . . . . .
. . - : ..
~6S76S
Inlet pipe 31 is located to surround the vertical portion 30 of the removal line 26. This permits symmetrical flow of the sewage introduced into the basin 1, and similarly essentially symmetrical distribution of the sewage S through the openings 4 into the basin 1.
The invention has been described with respect to a circular basin. The arrangement of the piping having a -~
movable, sealed joint between a fixed pipe part and a movable part effectively makes the suction nozzle 17 the suction opening for a fixed pumping station 28 located outside of the basin 1. In similar manner, a basin having a rectangular outline can be used; connection between the ixed and movable piping portions can then be obtained by telescoping pipes, for example, with the same advantages as those which are o ffl ainable with a circular basin as specifically described ; in connection with Fig. l.
: ~ .
Various changes and modifications may be made within the scope of the inventive concept.
'~
, ~. ~
,. ~
..
Claims (10)
1. Sludge removal system in combination with a sludge settling tank to remove sludge which settled out at the bottom of the tank comprising a support bridge located above the tank and movable in a path over the tank:
means removing the sludge from the bottom of the tank, as the bridge is moving while excluding access of air at ambient pressure to said sludge and forming an hydraulic-ally closed suction fluid conduit to remove said sludge, including a suction nozzle and a suction riser pipe supported from the bridge and extending into the tank to sweep the bottom of the tank upon movement of the bridge in its path;
a fixed sludge removal pipe located at least in part below the bottom of the tank, fixed with respect to the tank, immovably secured thereto and having a vertically extending fixed pipe portion;
a connecting pipe means supported from and moving with the bridge including a horizontal portion located above the highest liquid level joined to the suction riser pipe and an end portion extending vertically downwardly, and aligned with the vertically extending portion of the fixed sludge removal pipe;
and a movable joint which is substantially liquid-tight and tight with respect to subatmospheric pressure con-necting the vertical end portion of the connecting pipe means and the sludge removal pipe;
and a pump located laterally with respect to the tank and having a suction inlet connection connected to the sludge removal pipe and hence to the hydraulically closed fluid conduit to provide a suction fluid circuit which is hydraulically closed from the nozzle below the liquid level through the pipe portion above the liquid level and then to the laterally located pump while permitting relative movement of the nozzle in its path over the sludge settling tank.
means removing the sludge from the bottom of the tank, as the bridge is moving while excluding access of air at ambient pressure to said sludge and forming an hydraulic-ally closed suction fluid conduit to remove said sludge, including a suction nozzle and a suction riser pipe supported from the bridge and extending into the tank to sweep the bottom of the tank upon movement of the bridge in its path;
a fixed sludge removal pipe located at least in part below the bottom of the tank, fixed with respect to the tank, immovably secured thereto and having a vertically extending fixed pipe portion;
a connecting pipe means supported from and moving with the bridge including a horizontal portion located above the highest liquid level joined to the suction riser pipe and an end portion extending vertically downwardly, and aligned with the vertically extending portion of the fixed sludge removal pipe;
and a movable joint which is substantially liquid-tight and tight with respect to subatmospheric pressure con-necting the vertical end portion of the connecting pipe means and the sludge removal pipe;
and a pump located laterally with respect to the tank and having a suction inlet connection connected to the sludge removal pipe and hence to the hydraulically closed fluid conduit to provide a suction fluid circuit which is hydraulically closed from the nozzle below the liquid level through the pipe portion above the liquid level and then to the laterally located pump while permitting relative movement of the nozzle in its path over the sludge settling tank.
2. System according to claim 1, wherein a single pump is provided and valve means selectively connecting the sludge removal pipe to the suction inlet connection or to the pressure outlet connection of the pump to provide selectively for pumping of sludge or for pressurized back-flushing with said single pump through the closed fluid conduit.
3. System according to claim 1, wherein a plurality of suction nozzles are provided, each suction nozzle having a riser pipe associated therewith, and in communication with the connecting pipe means, and valve means connecting the individual riser pipes to the connecting pipe means to individually control flow through the respective pipe means and connected suction nozzle and through the connecting pipe means.
4. System according to claim 1, wherein the movable joint is located below the operating liquid level of the settling tank.
5. System according to claim 1, wherein the tank is of circular plan outline, a central inlet structure is provided, the movable joint is a rotary joint and located at the center of the tank ;
the bridge extending radially and being supported from the central structure, a drive motor secured to the central structure and drive means having one part associated with the bridge and another part associated with the motor to movably drive the bridge in rotary movement in a sweep path over the basin upon operation of the motor.
the bridge extending radially and being supported from the central structure, a drive motor secured to the central structure and drive means having one part associated with the bridge and another part associated with the motor to movably drive the bridge in rotary movement in a sweep path over the basin upon operation of the motor.
6. System according to claim 1, further comprising an inlet structure to introduce liquid fluid into the settling tank, wherein the movable joint is located in fluid communication with the inlet structure so that any leakage from said joint will be returned into the tank.
7. System according to claim 6, wherein the tank is of circular plan outline, the inlet structure comprises a central tubular inlet, and includes an inlet outflow pipe located at the center of the circular tank;
and the movable joint is a rotary joint, located coaxially with the center of the tank and above the outflow of the inlet pipe.
and the movable joint is a rotary joint, located coaxially with the center of the tank and above the outflow of the inlet pipe.
8. Method to remove sludge from the bottom of a settling tank having a movable nozzle in fluid communication with the bottom of the tank, and a closed fluid piping conduit connected to the movable nozzle including a fixed sludge removal pipe from which the sludge is discharged extending transversely of the tank and located below the tank, a movable riser extending from the movable nozzle to above the operating liquid level of the tank, a movable transverse connecting pipe located above the highest level of the tank and extending transversely of the tank, and an essentially liquid-tight, suction-tight rotary joint connecting the movable transverse connecting pipe and a fixed downwardly extending pipe jointed to said fixed transversely extending pipe to provide an essentially hydraulically completely suction-tight closed fluid conduit from the nozzle to the terminal end of the transversely extending pipe, comprising the steps of moving said nozzle, and removing sludge from the bottom of the tank as the nozzle is moving while excluding access of air at ambient pressure to said sludge by applying suction to the transversely extending pipe in excess of the pressure head generated by the level of liquid in the tank to apply the suction in the closed fluid conduit as said nozzle is moving."
9. Method according to claim 8, wherein the step of applying suction comprises connecting the transversely extending pipe directly to a suction pump."
10. Method according to claim 8, wherein the step of applying suction to the downwardly extending pipe comprises the step of connecting said pipe to the suction inlet of a pump for a predetermined period of time;
and further comprising the step of connecting said pipe, selectively, and at a different time to the pressure outlet of the pump and introducing flushing liquid to the suction inlet of the pump to provide reverse flow of liquid through said downwardly extending pipe, transversely extending connection and the riser pipe and suction nozzle to provide flushing.
and further comprising the step of connecting said pipe, selectively, and at a different time to the pressure outlet of the pump and introducing flushing liquid to the suction inlet of the pump to provide reverse flow of liquid through said downwardly extending pipe, transversely extending connection and the riser pipe and suction nozzle to provide flushing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH1127574A CH570942A5 (en) | 1974-08-19 | 1974-08-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1065765A true CA1065765A (en) | 1979-11-06 |
Family
ID=4371870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA233,284A Expired CA1065765A (en) | 1974-08-19 | 1975-08-12 | Sludge removal system and settling tank combination |
Country Status (20)
| Country | Link |
|---|---|
| JP (1) | JPS594166B2 (en) |
| AR (1) | AR205401A1 (en) |
| AT (1) | AT342523B (en) |
| BE (1) | BE832550A (en) |
| BR (1) | BR7505257A (en) |
| CA (1) | CA1065765A (en) |
| CH (1) | CH570942A5 (en) |
| DD (1) | DD120420A5 (en) |
| DE (1) | DE2535636A1 (en) |
| DK (1) | DK372975A (en) |
| ES (1) | ES440232A1 (en) |
| FI (1) | FI752335A (en) |
| FR (1) | FR2282406A1 (en) |
| GB (1) | GB1501480A (en) |
| IL (1) | IL47908A (en) |
| IT (1) | IT1040383B (en) |
| NL (1) | NL7509822A (en) |
| NO (1) | NO148057C (en) |
| SE (1) | SE432714B (en) |
| ZA (1) | ZA755216B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106422443A (en) * | 2016-06-23 | 2017-02-22 | 南通荣恒环保设备有限公司 | Sludge discharging machine used for sewage treatment |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3507365A1 (en) * | 1984-10-15 | 1986-04-24 | Hugo Dipl.-Ing. 4300 Essen Kahl | Round tank for waste water secondary clarification |
| DE19718499B4 (en) * | 1997-05-02 | 2004-01-29 | Franz, Heiko, Takapuna | Device for solids and sludge removal in sedimentation basins |
| DE19806858A1 (en) * | 1998-02-19 | 2000-05-25 | Emschergenossenschaft Lippever | Sedimentation basin with a round shape for separating sludge from waste water |
| JP4549551B2 (en) * | 2001-02-13 | 2010-09-22 | 東京都 | Mud sampling equipment |
| JP6727027B2 (en) * | 2016-05-12 | 2020-07-22 | 株式会社日立製作所 | Sand removal equipment for sand basins |
| JP6727100B2 (en) * | 2016-10-31 | 2020-07-22 | 株式会社日立製作所 | Sand removal equipment for sand basins |
| JP6833752B2 (en) | 2018-03-23 | 2021-02-24 | 株式会社東芝 | Rechargeable batteries, battery packs, vehicles and stationary power supplies |
| CN110384963A (en) * | 2018-04-23 | 2019-10-29 | 宁波碧源供水有限公司 | A kind of suction dredge |
| RU2761195C1 (en) * | 2021-01-11 | 2021-12-06 | Федеральное государственное казённое военное образовательное учреждение высшего образования "Военная академия материально-технического обеспечения имени генерала армии А.В. Хрулева" Министерства обороны Российской Федерации | Device for separation of activated sludge into fractions |
| CN113262529A (en) * | 2021-05-28 | 2021-08-17 | 成渝钒钛科技有限公司 | Vanadium extraction wastewater resource comprehensive utilization filtering device and use method thereof |
| CN114768312A (en) * | 2022-03-28 | 2022-07-22 | 芜湖华衍水务有限公司 | Domestic sewage treatment device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE372178C (en) * | 1923-03-27 | Abwasser & Wasserreinigungs Ge | Method and device for removing water-poor sewage sludge under water | |
| DE519016C (en) * | 1928-11-16 | 1931-02-23 | Klaer U Entphenolungsgesellsch | Sludge suction device for sewage wells |
| DE1784503A1 (en) * | 1968-08-14 | 1971-08-19 | Koppers Gmbh Heinrich | Sludge scraper for round pits |
| JPS4956564U (en) * | 1972-08-29 | 1974-05-18 |
-
1974
- 1974-08-19 CH CH1127574A patent/CH570942A5/xx not_active IP Right Cessation
-
1975
- 1975-01-01 AR AR260039A patent/AR205401A1/en active
- 1975-08-06 SE SE7508862A patent/SE432714B/en unknown
- 1975-08-08 IT IT26233/75A patent/IT1040383B/en active
- 1975-08-09 DE DE19752535636 patent/DE2535636A1/en active Granted
- 1975-08-12 CA CA233,284A patent/CA1065765A/en not_active Expired
- 1975-08-12 IL IL47908A patent/IL47908A/en unknown
- 1975-08-13 ZA ZA00755216A patent/ZA755216B/en unknown
- 1975-08-13 ES ES440232A patent/ES440232A1/en not_active Expired
- 1975-08-13 AT AT627875A patent/AT342523B/en not_active IP Right Cessation
- 1975-08-14 GB GB33927/75A patent/GB1501480A/en not_active Expired
- 1975-08-14 FR FR7525403A patent/FR2282406A1/en active Granted
- 1975-08-15 DD DD187890A patent/DD120420A5/xx unknown
- 1975-08-18 DK DK372975A patent/DK372975A/en unknown
- 1975-08-18 FI FI752335A patent/FI752335A/fi not_active Application Discontinuation
- 1975-08-18 NO NO75752859A patent/NO148057C/en unknown
- 1975-08-18 BR BR7505257*A patent/BR7505257A/en unknown
- 1975-08-18 NL NL7509822A patent/NL7509822A/en not_active Application Discontinuation
- 1975-08-19 JP JP50100560A patent/JPS594166B2/en not_active Expired
- 1975-08-19 BE BE159303A patent/BE832550A/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106422443A (en) * | 2016-06-23 | 2017-02-22 | 南通荣恒环保设备有限公司 | Sludge discharging machine used for sewage treatment |
Also Published As
| Publication number | Publication date |
|---|---|
| IT1040383B (en) | 1979-12-20 |
| DE2535636C2 (en) | 1987-07-30 |
| FR2282406B1 (en) | 1980-07-25 |
| BR7505257A (en) | 1976-08-03 |
| AU8396775A (en) | 1977-02-17 |
| ES440232A1 (en) | 1977-03-16 |
| NO148057C (en) | 1983-08-03 |
| ZA755216B (en) | 1976-07-28 |
| BE832550A (en) | 1976-02-19 |
| JPS594166B2 (en) | 1984-01-28 |
| AR205401A1 (en) | 1976-04-30 |
| NL7509822A (en) | 1976-02-23 |
| IL47908A0 (en) | 1975-11-25 |
| FR2282406A1 (en) | 1976-03-19 |
| IL47908A (en) | 1978-12-17 |
| AT342523B (en) | 1978-04-10 |
| NO752859L (en) | 1976-02-20 |
| SE432714B (en) | 1984-04-16 |
| DD120420A5 (en) | 1976-06-12 |
| GB1501480A (en) | 1978-02-15 |
| JPS5145447A (en) | 1976-04-17 |
| NO148057B (en) | 1983-04-25 |
| DE2535636A1 (en) | 1976-03-04 |
| DK372975A (en) | 1976-02-20 |
| FI752335A (en) | 1976-02-20 |
| ATA627875A (en) | 1977-07-15 |
| SE7508862L (en) | 1976-02-20 |
| CH570942A5 (en) | 1975-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1065765A (en) | Sludge removal system and settling tank combination | |
| JP2008272671A (en) | Integrated type solid/liquid separation system and filter apparatus | |
| US5340485A (en) | Apparatus and method for clarifier sludge collection | |
| US20100018913A1 (en) | Filter and sterilization apparatus | |
| DK162632B (en) | System for filtering out solids from a turbid liquid | |
| EP0626877B1 (en) | Decanting apparatus | |
| US5219470A (en) | Apparatus and method for clarifier sludge collection | |
| CN107185755A (en) | The washer jet of disinfection protection set is installed | |
| JPS5912322B2 (en) | Improved sludge bed settling equipment | |
| JPH05501532A (en) | Liquid suction device | |
| US6146530A (en) | Process and apparatus for removing particles of paint overspray from an aqueous turbid liquid | |
| US3672512A (en) | Static thickener and hydraulic rake therefor | |
| CN110304702A (en) | A kind of water purification installation | |
| KR100303230B1 (en) | Method and apparatus for wet processing of substrates in containers | |
| JPH0290904A (en) | Apparatus for removing sewage sludge from bottom part or surface layer part of sedimentation tank | |
| US4144172A (en) | Industrial liquid cleansing apparatus | |
| CN2180317Y (en) | Sewage treatment device with removing device for accumulated dirt | |
| US20040226880A1 (en) | Apparatus for collecting and conveying clean liquor from a separating tank and systems utilizing same | |
| US20160161037A1 (en) | Foldable drain pipe for a decanter in a water treatment system | |
| US20040050407A1 (en) | Apparatus for the automatic cleaning of liquid storage tanks | |
| JP3914323B2 (en) | Sand lifting equipment | |
| CN208824001U (en) | Water-discharging and sand-removing device for crude oil settling tank | |
| KR101508935B1 (en) | Sludge discharging apparatus | |
| CN220274267U (en) | Gardens liquid manure irrigation equipment | |
| US1337094A (en) | Sedimentation apparatus |