CA1088229A - Backflushing method and system - Google Patents
Backflushing method and systemInfo
- Publication number
- CA1088229A CA1088229A CA292,707A CA292707A CA1088229A CA 1088229 A CA1088229 A CA 1088229A CA 292707 A CA292707 A CA 292707A CA 1088229 A CA1088229 A CA 1088229A
- Authority
- CA
- Canada
- Prior art keywords
- fluid
- gas
- pump
- inlet
- passage
- 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
- 238000000034 method Methods 0.000 title claims abstract description 11
- 239000002351 wastewater Substances 0.000 claims abstract description 19
- 230000010349 pulsation Effects 0.000 claims abstract description 4
- 239000007789 gas Substances 0.000 claims description 32
- 238000005086 pumping Methods 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 4
- 239000001301 oxygen Substances 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 230000002349 favourable effect Effects 0.000 claims description 2
- 239000012530 fluid Substances 0.000 claims 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 19
- 230000000332 continued effect Effects 0.000 abstract 1
- 238000011010 flushing procedure Methods 0.000 description 5
- 238000005273 aeration Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- 238000005276 aerator Methods 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- -1 hair Substances 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An improved method and system for aerating and mixing waste water which is circulated through a plurality of passages in submerged mixing chambers from an inlet to outlet of each wherein gas is mixed with the water, preferably by forming two parallel streams. To flush debris from the mixing chambers and conduits: (1) each inlet is connected to a location higher than the inlet, and at a lower pressure; (2) circulation of water is stopped; and (3) gas is con-tinued to be forced into the passages to create backward flow of waste water through each chamber from outlet to inlet and thence to the higher location, carrying lodged debris out of the chambers and conduits. Inter-mittent gas flow creates pulsations which help dislodge debris.
An improved method and system for aerating and mixing waste water which is circulated through a plurality of passages in submerged mixing chambers from an inlet to outlet of each wherein gas is mixed with the water, preferably by forming two parallel streams. To flush debris from the mixing chambers and conduits: (1) each inlet is connected to a location higher than the inlet, and at a lower pressure; (2) circulation of water is stopped; and (3) gas is con-tinued to be forced into the passages to create backward flow of waste water through each chamber from outlet to inlet and thence to the higher location, carrying lodged debris out of the chambers and conduits. Inter-mittent gas flow creates pulsations which help dislodge debris.
Description
~088'~Z9 ~RIEF DESCRIPTION OF THE INVENTION BACKGROUND
AN~ SUMMARY OF THE INVEN~ION
The invention relates to an improved method and submerged system for efficiently mixing gas with waste water and for flushing accumulated debris from such submerged system.
Industrial waste, sewage and the like are commonly purified by pumping the li~uid into a large tank, pond or b~sin where a bacteria population consumes the inorganic and organic material. Because the dissolved oxygen in the waste water is usually insufficient to support the required population of bacteria, the water must be aerated. This can be done with a surface aerating machine which has beaters extending into the waste water from above the water surface to agitate the water and incorporate air. Alternatively, air can be diffused through the bottom of the basin, e.g., through a porous medium.
Surface aerators are not efficient and cause certain mechanical problems. The energy loss of diffusing air is also great and a diffused system is not suitable for installation in an existing pond.
Waste water can also be aerated by pumping through submerged tubes with openings through which air is drawn or pumped into the tubes to create turbulent mixing. Such devices include vortex, jet, Venturi and impingement type devices and are much more energy ef~icient than diffusion or surface aerator systems.
One problem which can arise with systems o~ this sort in which water and gas are mixed in a chamber is that small particles in an aeration basin, tank or pond can be caught within the mixing chambers, the pump or the conduits therebetween, to eventually clog the same. In sewage treatment, material such as hair, paper, cloth, etc. will become lodged in the `~
.... , . .. , ~ .
.. .,: .. . . : .
-: '' , ~. :
1088Z~9 chambers, eventually blocking water flow and reducing the effect-iveness of the system. Since submerged systems of this type normally pump a great volume of water, even a small number of particles in the body of waste water will eventually become lodged within the mixing chambers. It is not normally desirable to shut down the system for maintenance, and removal of this material, even when the basin is drained, can be a difficult task.
However, these systems can be flushed of such debris by directly or indirectly connecting the inlets of each of the mixing chambers to which waste water is normally supplied for aeration to a higher, backflush location closer to or above water surface. If the pump is turned off while air continues to flow into the chambers, the difference in pressure between the water at the mixing chambers and the higher location causes flow of the air backward through the inlets to that back-flush location to flush the system.
Surprisingly, the air pumps waste water at a substantial flow rate and pressure backward through the system. A separate line can be used with a valve to flush the debris directly above the surface where it can be collected. The waste water can be back-flushed through the pump to clean the pump screen provided that the pump and its strainer are mounted above the mixing chambers.
The air can be intermittently turned on and off to create pulsations of water which act as a hammer to dislodge debris.
Other objects and purposes of the invention will be clear from the following detailed description of the drawings.
,~ . .:
BRIEF DESCRIPTION OF THE DRAWINGS:
FIGURE 1 shows a schematic side view of the system of the present invention in use;
FIGURE 2 shows a planar view of the system of FIGURE l;
FIGURE 3 shows a sectional view of a mixing chamber of the present invention;
FIGURE 4 shows a sectional view of a helical air mixing chamber;
FIGURE 5 shows a partial sectional view of the mixing chamber of FIGURE 4;
FIGURE 6 shows a schematic view of another embodiment;
FIGURES 7 and 8 show a further embodimènt.
DETAILED DESCRIPTION OF ~HE DRAWINGS:
.
Reference is now made to FIGURES 1 and 2 which schematically illustrate one embodiment of the present in-vention. In the embodiment of FIGURES 1 and 2, a plurality ~ .
of circumferentially disposed mixing chambers 20, each preferably identical to the other, are circularly disposed around a dome ;
manlfold 22 which include~ an upper section 24 into which water is pumped and a lower section 26 connected to a source ~ .
of air or oxygen at a suitable pressure. Each of the mixing chambers is of the type shown in detail in FIGURES 3-5 and discussed in detail below.
lO~B~29 A plurality of conduits 30, ea~h formed of a metal segment 32 and a plastic segment 34 connect section 24 to each mixing chamber 20 so that water is continuously pumped through each chamber 20. A similar series of conduits 40 formed of metal portion 42 and a plastic portion 44 also connect section 26 to each of the mixing chambers 20. As will be apparent below, each of the mixing chambers forms parallel streams of air and gas which interact within an extending chamber of the mixing chamber to form tiny bubbles which efficiently mix with the pumped waste water. Manifold 22 is suspended from a fibreglass floating work platform 50 by means ~f guide bars 52 and 54 and two bars behind them in Figure 1. Industrial air piping conduit 60 is attached to guide bar S4 for supplying air to section 26. C~ble 62 connects the manifold 22 to a frame 64 on platform 50 for lifting manifold 22 and holding manifold 22 in position for maintenance.
A conventional submersible pump 66 is mounted above manifold 22 and includes an optional strainer basket 67 which keeps most debris from entering the pump and being lodged therein. For many installations the basket can be omitted and the debris which collects in the pump, backflushed as described below. Conduit 68 connects pump 66 to section 24.
Floating work platform 50 is provided with suitable railings 70 of a height so that the unit can be lifted to a level for convenient work on the mixing chambers and pump.
An on-shore air pump 74 is schematically shown as connected to line 60 for pumping air, oxygen or other gas to section 26 for mixing with the pumped waste water.
When it is desired to clean the inevitable particles and debris which will accumulate within the pump 66 and the mixing chamber 20, pump 66 can simply be turned off while the 1088Z~9 air pump 74 continues forcing air into the mixing chambers.
However, surprisingly, instead of moving out of the outlet, the air will pump waste water back through the inlet, opposite to the direction of flow during aeration, through conduits 34 and 32 into section 22, through conduit 68 and through pump 66, blowing off the debris which has accumulated on the outside of strainer basket 67. This occurs because the water pressure at the level of the strainer basket is lower than the water pressure at the level of the mixing chambers 20. The outlet -point for the back-flushing should be as close to the waterline as possible. Alternatively, flushing can be accomplished by operating a valve 76 in a line 78 which connects to conduit 68.
With many pumps, particularly those mounted out of the water, ~ -flushing through a separate line is preferable to flushing -through the pump. The debris will now be blown into the air and since the pressure differential is greater, the force ~ -produced, by the air which works as an air hammer, will blow the debris through the system and back-flush all of the material in a few minutes. Turning the air on and off ~`
repeatedly creates pulsations which will dislodge almost all debris and back-flush it from the system.
FIGURES 3-5 illustrate the unique mixing chamber 20 of the present invention. Waste water flows from the inlet through passage 100 into the extending chamber 102. At the intersection between passage lOO and section 102, a step region 104 is provided at which a plurality of bores terminates. To keep the vortices within chamber 102 at high air pressure, the bores inject the gas at an angle between roughly 11 and 22 1/2. A chamber with helical vanes in the bores as shown in FIGURES 4 and 5 creates greater wave generating conditions.
i~, .
1 .... .. . . .
,, 1~88229 Thus, two parallel stream~ of gas and waste water are created as shown in FIGUPE 3. As streams move along the chamber 102, the friction between them causes waves to form and the air thus trapped in waves to disperse into tiny bubbles. Since the air and gas streams move in the same direction, effective mixing is achieved at minimum energy consumption. It is desirahle that under most co~ditions the mixing take place within chamber 102 and for that reason the chamber is slightly tapered inwardly within the portion 110 with the cross-section decreasing in the direction from inlet to outlet and more radically tapered within portion 112.
These tapers extend the maximum air flow rate with which the system will operate by several times without sub-stantial loss of efficiency.
The helical guide vanes 106 ~rovide a twi ting motion to the air and thus create more waves which also help the interface break up more quickly by creating instability.
The mixing chambers can be made of any suitable materials such as stainless steel, aluminum or plastic.
;~ FIGURE 6 shows another embodiment in which the submersible pump is replaced with a conventional waste :: :
;water pump 200 mounted beside tank 202 and oonnected to manifold 204 by line 206- Pump 200 has an inlet 207. A ~lurality of mixing chambers 208 are mounted about manifold 204 and can be any suitable mixing device such as a jet, vortex, Venturi or impingement type device. Air pum~ 210 is also mounted beside tank 202 and is connected to manifold 204 by line 212. Valve 214~can be opened to back-flush waste water as described above while pump 200 is turned off and .
" ;~, ., , .. . - - .:
,: : .
. , ~..... . .
''' : ' ,- .' ` , .. ,:. . : . , , 10~8;~2g pump 210 continues to force gas into the mixing chambers of device 208. The gas then pumps the waste water back through manifold 204 and line 212 where it leaves via valve 214. The waste water returns to the tank and the debris is caught in strainer 216 if desired.
FIGU~ES 7 and 8 illustrate yet another embodiment of the invention which utilizes mixing chambers as described above. In the arrangement of FI~URES 7 and 8, water in a suitable tank 300 is pumped through a straight line pipe 302 by a pump 304. A plu_ality of mixing chambers 306 extend outwardly from pipe 302 at separated locations as shown in FI~URE 7. Air is supplied to a second pipe 308 which extends above and parallel to pipe 302. Alternatively, -~
one pipe can be within the other. Pipe 308 is connected to the individual mixing chambers for injecting air into those chambers. ~ipes 302 and 308 preferably extend along the center of the basin 300 parallel to the edges so as to cause a favorable pattern of water flow from one side to the other using a minimum amount of energy to create maximum flow and aeration. The system is flushed by opening valve 310 while pump 304 is turned off and air continued to be supplied to chambers 306.
Many changes and modifications in the above described embodiments of the invention can, of course, be carried out with-out departing from the scope of the invention. The system can be used with non-aqueous liquids and gas other than air such as pure oxygen can be added. Accordingly, that scope is intended to be limited only by the scope of the appended claims.
AN~ SUMMARY OF THE INVEN~ION
The invention relates to an improved method and submerged system for efficiently mixing gas with waste water and for flushing accumulated debris from such submerged system.
Industrial waste, sewage and the like are commonly purified by pumping the li~uid into a large tank, pond or b~sin where a bacteria population consumes the inorganic and organic material. Because the dissolved oxygen in the waste water is usually insufficient to support the required population of bacteria, the water must be aerated. This can be done with a surface aerating machine which has beaters extending into the waste water from above the water surface to agitate the water and incorporate air. Alternatively, air can be diffused through the bottom of the basin, e.g., through a porous medium.
Surface aerators are not efficient and cause certain mechanical problems. The energy loss of diffusing air is also great and a diffused system is not suitable for installation in an existing pond.
Waste water can also be aerated by pumping through submerged tubes with openings through which air is drawn or pumped into the tubes to create turbulent mixing. Such devices include vortex, jet, Venturi and impingement type devices and are much more energy ef~icient than diffusion or surface aerator systems.
One problem which can arise with systems o~ this sort in which water and gas are mixed in a chamber is that small particles in an aeration basin, tank or pond can be caught within the mixing chambers, the pump or the conduits therebetween, to eventually clog the same. In sewage treatment, material such as hair, paper, cloth, etc. will become lodged in the `~
.... , . .. , ~ .
.. .,: .. . . : .
-: '' , ~. :
1088Z~9 chambers, eventually blocking water flow and reducing the effect-iveness of the system. Since submerged systems of this type normally pump a great volume of water, even a small number of particles in the body of waste water will eventually become lodged within the mixing chambers. It is not normally desirable to shut down the system for maintenance, and removal of this material, even when the basin is drained, can be a difficult task.
However, these systems can be flushed of such debris by directly or indirectly connecting the inlets of each of the mixing chambers to which waste water is normally supplied for aeration to a higher, backflush location closer to or above water surface. If the pump is turned off while air continues to flow into the chambers, the difference in pressure between the water at the mixing chambers and the higher location causes flow of the air backward through the inlets to that back-flush location to flush the system.
Surprisingly, the air pumps waste water at a substantial flow rate and pressure backward through the system. A separate line can be used with a valve to flush the debris directly above the surface where it can be collected. The waste water can be back-flushed through the pump to clean the pump screen provided that the pump and its strainer are mounted above the mixing chambers.
The air can be intermittently turned on and off to create pulsations of water which act as a hammer to dislodge debris.
Other objects and purposes of the invention will be clear from the following detailed description of the drawings.
,~ . .:
BRIEF DESCRIPTION OF THE DRAWINGS:
FIGURE 1 shows a schematic side view of the system of the present invention in use;
FIGURE 2 shows a planar view of the system of FIGURE l;
FIGURE 3 shows a sectional view of a mixing chamber of the present invention;
FIGURE 4 shows a sectional view of a helical air mixing chamber;
FIGURE 5 shows a partial sectional view of the mixing chamber of FIGURE 4;
FIGURE 6 shows a schematic view of another embodiment;
FIGURES 7 and 8 show a further embodimènt.
DETAILED DESCRIPTION OF ~HE DRAWINGS:
.
Reference is now made to FIGURES 1 and 2 which schematically illustrate one embodiment of the present in-vention. In the embodiment of FIGURES 1 and 2, a plurality ~ .
of circumferentially disposed mixing chambers 20, each preferably identical to the other, are circularly disposed around a dome ;
manlfold 22 which include~ an upper section 24 into which water is pumped and a lower section 26 connected to a source ~ .
of air or oxygen at a suitable pressure. Each of the mixing chambers is of the type shown in detail in FIGURES 3-5 and discussed in detail below.
lO~B~29 A plurality of conduits 30, ea~h formed of a metal segment 32 and a plastic segment 34 connect section 24 to each mixing chamber 20 so that water is continuously pumped through each chamber 20. A similar series of conduits 40 formed of metal portion 42 and a plastic portion 44 also connect section 26 to each of the mixing chambers 20. As will be apparent below, each of the mixing chambers forms parallel streams of air and gas which interact within an extending chamber of the mixing chamber to form tiny bubbles which efficiently mix with the pumped waste water. Manifold 22 is suspended from a fibreglass floating work platform 50 by means ~f guide bars 52 and 54 and two bars behind them in Figure 1. Industrial air piping conduit 60 is attached to guide bar S4 for supplying air to section 26. C~ble 62 connects the manifold 22 to a frame 64 on platform 50 for lifting manifold 22 and holding manifold 22 in position for maintenance.
A conventional submersible pump 66 is mounted above manifold 22 and includes an optional strainer basket 67 which keeps most debris from entering the pump and being lodged therein. For many installations the basket can be omitted and the debris which collects in the pump, backflushed as described below. Conduit 68 connects pump 66 to section 24.
Floating work platform 50 is provided with suitable railings 70 of a height so that the unit can be lifted to a level for convenient work on the mixing chambers and pump.
An on-shore air pump 74 is schematically shown as connected to line 60 for pumping air, oxygen or other gas to section 26 for mixing with the pumped waste water.
When it is desired to clean the inevitable particles and debris which will accumulate within the pump 66 and the mixing chamber 20, pump 66 can simply be turned off while the 1088Z~9 air pump 74 continues forcing air into the mixing chambers.
However, surprisingly, instead of moving out of the outlet, the air will pump waste water back through the inlet, opposite to the direction of flow during aeration, through conduits 34 and 32 into section 22, through conduit 68 and through pump 66, blowing off the debris which has accumulated on the outside of strainer basket 67. This occurs because the water pressure at the level of the strainer basket is lower than the water pressure at the level of the mixing chambers 20. The outlet -point for the back-flushing should be as close to the waterline as possible. Alternatively, flushing can be accomplished by operating a valve 76 in a line 78 which connects to conduit 68.
With many pumps, particularly those mounted out of the water, ~ -flushing through a separate line is preferable to flushing -through the pump. The debris will now be blown into the air and since the pressure differential is greater, the force ~ -produced, by the air which works as an air hammer, will blow the debris through the system and back-flush all of the material in a few minutes. Turning the air on and off ~`
repeatedly creates pulsations which will dislodge almost all debris and back-flush it from the system.
FIGURES 3-5 illustrate the unique mixing chamber 20 of the present invention. Waste water flows from the inlet through passage 100 into the extending chamber 102. At the intersection between passage lOO and section 102, a step region 104 is provided at which a plurality of bores terminates. To keep the vortices within chamber 102 at high air pressure, the bores inject the gas at an angle between roughly 11 and 22 1/2. A chamber with helical vanes in the bores as shown in FIGURES 4 and 5 creates greater wave generating conditions.
i~, .
1 .... .. . . .
,, 1~88229 Thus, two parallel stream~ of gas and waste water are created as shown in FIGUPE 3. As streams move along the chamber 102, the friction between them causes waves to form and the air thus trapped in waves to disperse into tiny bubbles. Since the air and gas streams move in the same direction, effective mixing is achieved at minimum energy consumption. It is desirahle that under most co~ditions the mixing take place within chamber 102 and for that reason the chamber is slightly tapered inwardly within the portion 110 with the cross-section decreasing in the direction from inlet to outlet and more radically tapered within portion 112.
These tapers extend the maximum air flow rate with which the system will operate by several times without sub-stantial loss of efficiency.
The helical guide vanes 106 ~rovide a twi ting motion to the air and thus create more waves which also help the interface break up more quickly by creating instability.
The mixing chambers can be made of any suitable materials such as stainless steel, aluminum or plastic.
;~ FIGURE 6 shows another embodiment in which the submersible pump is replaced with a conventional waste :: :
;water pump 200 mounted beside tank 202 and oonnected to manifold 204 by line 206- Pump 200 has an inlet 207. A ~lurality of mixing chambers 208 are mounted about manifold 204 and can be any suitable mixing device such as a jet, vortex, Venturi or impingement type device. Air pum~ 210 is also mounted beside tank 202 and is connected to manifold 204 by line 212. Valve 214~can be opened to back-flush waste water as described above while pump 200 is turned off and .
" ;~, ., , .. . - - .:
,: : .
. , ~..... . .
''' : ' ,- .' ` , .. ,:. . : . , , 10~8;~2g pump 210 continues to force gas into the mixing chambers of device 208. The gas then pumps the waste water back through manifold 204 and line 212 where it leaves via valve 214. The waste water returns to the tank and the debris is caught in strainer 216 if desired.
FIGU~ES 7 and 8 illustrate yet another embodiment of the invention which utilizes mixing chambers as described above. In the arrangement of FI~URES 7 and 8, water in a suitable tank 300 is pumped through a straight line pipe 302 by a pump 304. A plu_ality of mixing chambers 306 extend outwardly from pipe 302 at separated locations as shown in FI~URE 7. Air is supplied to a second pipe 308 which extends above and parallel to pipe 302. Alternatively, -~
one pipe can be within the other. Pipe 308 is connected to the individual mixing chambers for injecting air into those chambers. ~ipes 302 and 308 preferably extend along the center of the basin 300 parallel to the edges so as to cause a favorable pattern of water flow from one side to the other using a minimum amount of energy to create maximum flow and aeration. The system is flushed by opening valve 310 while pump 304 is turned off and air continued to be supplied to chambers 306.
Many changes and modifications in the above described embodiments of the invention can, of course, be carried out with-out departing from the scope of the invention. The system can be used with non-aqueous liquids and gas other than air such as pure oxygen can be added. Accordingly, that scope is intended to be limited only by the scope of the appended claims.
Claims (23)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of operating a system for mixing gas with a fluid in a body of fluid comprising the steps of:
circulating said fluid in said body below the surface thereof through at least one passage in a mixing chamber from an inlet to an outlet;
causing gas to enter said passage so the gas and fluid are mixed in said passage as said fluid circulates through said passage; and connecting said inlet to a back-flush location above said inlet, said location having a lower pressure than the pressure at said inlet, while continuing to cause gas to enter said passage so that said gas causes backflow of said fluid from said outlet through said inlet to said lower pressure location to flush debris from said mixing chamber.
circulating said fluid in said body below the surface thereof through at least one passage in a mixing chamber from an inlet to an outlet;
causing gas to enter said passage so the gas and fluid are mixed in said passage as said fluid circulates through said passage; and connecting said inlet to a back-flush location above said inlet, said location having a lower pressure than the pressure at said inlet, while continuing to cause gas to enter said passage so that said gas causes backflow of said fluid from said outlet through said inlet to said lower pressure location to flush debris from said mixing chamber.
2. A method as in Claim 1, in which said step of connecting includes opening a valve in the line between the inlet and a pump which circulates the fluid.
3. A method as in Claim 2, in which said step of opening includes opening said valve above the surface of said fluid.
4. A method as in Claim 1, wherein said step of circulating includes pumping said fluid with a pump and said back-flow takes place through the pump and a strainer basket over the pump inlet to remove debris from the outside of said basket.
5. A method as in Claim 1, in which the fluid is waste water and the gas contains oxygen.
6. A method as in Claim 1, including the further step of intermittently cutting off the flow of gas during backflow to produce pulsations which dislodge debris.
7. A method as in Claim 1, wherein said fluid is circulated through a first pipe extending in a straight line and having said chambers extending outwardly therefrom at separated locations and said causing including supplying the gas through a second pipe extending parallel to said first pipe and connected to said chambers.
8. A method as in Claim 1, wherein said pipes extend in the middle of a tank to produce a favorable flow pattern.
9. A system for mixing gas with a fluid in a body of fluid comprising:
a plurality of mixing chambers disposed in said body, each having a passage for said fluid therethrough from an inlet to an outlet and at least one bore opening into said passage for supplying said gas into said passage for mixing with said fluid, said inlet being connected to a back-flush location higher than said inlet location and at a lower pressure;
a pump and means connecting said pump to said inlet for pumping said fluid through said passage; and means for supplying gas to said bores so that said gas is forced into said passage to mix with said fluid, said gas moving from said bore through said passage to said back-flush location to flush debris from said passage when said pump is inoperative.
a plurality of mixing chambers disposed in said body, each having a passage for said fluid therethrough from an inlet to an outlet and at least one bore opening into said passage for supplying said gas into said passage for mixing with said fluid, said inlet being connected to a back-flush location higher than said inlet location and at a lower pressure;
a pump and means connecting said pump to said inlet for pumping said fluid through said passage; and means for supplying gas to said bores so that said gas is forced into said passage to mix with said fluid, said gas moving from said bore through said passage to said back-flush location to flush debris from said passage when said pump is inoperative.
10. A system as in Claim 9, wherein connecting means includes a first straight pipe having mixing chambers connected thereto at separated locations and said supplying means includes a second pipe connected to said chambers.
11. A system as in Claim 9, wherein said pipes extend in the center of a tank.
12. A system as in Claim 9, wherein said gas supplying means includes a pump outside said body and means for connecting said pump to said mixing chambers.
13. A system as in Claim 9, wherein said body is a tank and including said tank.
14. A system as in Claim 9, further including a manifold separated into a first section connected to said pump and to said inlets and a second section connected to said bores and to said gas supplying means, said chambers extending radially outward from said first section.
15. A system as in Claim 14, including means for mounting said pump above said manifold in said body, said pump having an inlet in said body.
16. A system as in Claim 15, including a strainer basket over the inlet of said pump.
17. A system as in Claim 15, wherein said connecting means includes a conduit between said pump and manifold and further including a line connected to said conduit and extending out of said body and a valve in said line.
18. A system as in Claim 15, including a plurality of first conduits each connecting an inlet of said first section to one of said chambers and a plurality of second conduits each connecting said second section to one of said bores.
19. A system as in Claim 9, wherein said chamber includes a step region at which said bores terminate to produce parallel streams of gas and fluid in said passage.
20. A system as in Claim 9, including a first pipe connected to said pump and extending in a straight line with said chambers extending outward therefrom and a second pipe extending adjacent to and parallel to said first pipe, said second pipe being connected to each of said bores and to said gas supplying means.
21. A system as in Claim 20, including a tank for said body and wherein said pipes extend in the center of said tank.
22. A system as in Claim 20, including a line connecting said first pipe to the surface and a valve in said line.
23. A system for mixing gas with a fluid in a body of fluid comprising:
a plurality of mixing chambers disposed in said body, each having a main passage for said fluid therethrough from an inlet to an outlet and at least one further passage opening into said main passage for supplying said gas into said main passage for mixing with said fluid;
a line connecting each said inlet to a backflush location higher than that inlet location and at a lower pressure;
a valve in said line having an open position and a closed position;
a pump and means connecting said pump to each said inlet for pumping said fluid through each said main passage; and means for supplying gas to each said further passage so that said gas is forced into the associated main passage into which that further passage opens to mix with said fluid, said gas moving from that further passage through said associated main passage and said line to said backflush location to flush debris from said associated main passage when said pump is inoperative and said valve is in said open position.
a plurality of mixing chambers disposed in said body, each having a main passage for said fluid therethrough from an inlet to an outlet and at least one further passage opening into said main passage for supplying said gas into said main passage for mixing with said fluid;
a line connecting each said inlet to a backflush location higher than that inlet location and at a lower pressure;
a valve in said line having an open position and a closed position;
a pump and means connecting said pump to each said inlet for pumping said fluid through each said main passage; and means for supplying gas to each said further passage so that said gas is forced into the associated main passage into which that further passage opens to mix with said fluid, said gas moving from that further passage through said associated main passage and said line to said backflush location to flush debris from said associated main passage when said pump is inoperative and said valve is in said open position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA292,707A CA1088229A (en) | 1977-12-08 | 1977-12-08 | Backflushing method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA292,707A CA1088229A (en) | 1977-12-08 | 1977-12-08 | Backflushing method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088229A true CA1088229A (en) | 1980-10-21 |
Family
ID=4110243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA292,707A Expired CA1088229A (en) | 1977-12-08 | 1977-12-08 | Backflushing method and system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1088229A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106830332A (en) * | 2017-03-31 | 2017-06-13 | 长春工程学院 | The device and method of the inverse recirculation reactor Treating Municipal Sewage of air-flow continuum micromeehanics three |
-
1977
- 1977-12-08 CA CA292,707A patent/CA1088229A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106830332A (en) * | 2017-03-31 | 2017-06-13 | 长春工程学院 | The device and method of the inverse recirculation reactor Treating Municipal Sewage of air-flow continuum micromeehanics three |
| CN106830332B (en) * | 2017-03-31 | 2023-05-12 | 长春工程学院 | Device and method for treating urban sewage by reverse airflow continuous water inlet three-cycle reactor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4157304A (en) | Aeration method and system | |
| US4244821A (en) | Backflushing system | |
| US4152259A (en) | Backflushing method | |
| US6413418B2 (en) | System and method for oxygenation of waste water | |
| RU2139131C1 (en) | Reactor | |
| JP2002052330A (en) | Gas and liquid supply device | |
| CA2222394A1 (en) | A mixing and aeration unit | |
| CA1088229A (en) | Backflushing method and system | |
| KR100463401B1 (en) | Wastewater disposal plant | |
| CA1330671C (en) | Aeration device with a protection skirt | |
| EP0428747A1 (en) | Method and apparatus of filtering medium circulation type for purifying contaminated water | |
| KR100882818B1 (en) | An aeration apparatus | |
| JP3582036B2 (en) | Gas-liquid contact device | |
| CA1063265A (en) | Liquid aeration device | |
| JP4374885B2 (en) | Membrane separator | |
| CA1088228A (en) | Aeration method and system | |
| CA1082375A (en) | Method and system for aeration of waste liquids | |
| KR102008646B1 (en) | Width-of-air equipment for sewage treatment plants | |
| GB1586819A (en) | Backflushing method and apparatus | |
| US3116347A (en) | Sewage treating device | |
| GB1596190A (en) | Aeration method and apparatus for carrying it out | |
| JPS59206096A (en) | Aerating apparatus | |
| RU95114539A (en) | METHOD FOR BIOLOGICAL SEWAGE TREATMENT AND DEVICE FOR ITS IMPLEMENTATION | |
| KR200337130Y1 (en) | Bath water purifying apparatus | |
| JPS6024407Y2 (en) | Bypass mixing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |