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GB2582980A - Improvements to sewage treatment plants - Google Patents

Improvements to sewage treatment plants Download PDF

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Publication number
GB2582980A
GB2582980A GB1905226.5A GB201905226A GB2582980A GB 2582980 A GB2582980 A GB 2582980A GB 201905226 A GB201905226 A GB 201905226A GB 2582980 A GB2582980 A GB 2582980A
Authority
GB
United Kingdom
Prior art keywords
discs
air
generating device
bubble generating
air bubble
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.)
Withdrawn
Application number
GB1905226.5A
Other versions
GB201905226D0 (en
Inventor
Howard Stanwell-Smith Colin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB1905226.5A priority Critical patent/GB2582980A/en
Publication of GB201905226D0 publication Critical patent/GB201905226D0/en
Publication of GB2582980A publication Critical patent/GB2582980A/en
Withdrawn legal-status Critical Current

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Classifications

    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F7/00Aeration of stretches of water
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • C02F3/02Aerobic processes
    • C02F3/12Activated sludge processes
    • C02F3/20Activated sludge processes using diffusers
    • C02F3/201Perforated, resilient plastic diffusers, e.g. membranes, sheets, foils, tubes, hoses
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/231Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids by bubbling
    • B01F23/23105Arrangement or manipulation of the gas bubbling devices
    • B01F23/2312Diffusers
    • B01F23/23121Diffusers having injection means, e.g. nozzles with circumferential outlet
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/231Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids by bubbling
    • B01F23/23105Arrangement or manipulation of the gas bubbling devices
    • B01F23/2312Diffusers
    • B01F23/23126Diffusers characterised by the shape of the diffuser element
    • B01F23/23127Screens, nets, grades or grids
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/232Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles
    • B01F23/2323Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles by circulating the flow in guiding constructions or conduits
    • B01F23/23231Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles by circulating the flow in guiding constructions or conduits being at least partially immersed in the liquid, e.g. in a closed circuit
    • B01F23/232311Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using flow-mixing means for introducing the gases, e.g. baffles by circulating the flow in guiding constructions or conduits being at least partially immersed in the liquid, e.g. in a closed circuit the conduits being vertical draft pipes with a lower intake end and an upper exit end
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • C02F3/02Aerobic processes
    • C02F3/12Activated sludge processes
    • C02F3/1236Particular type of activated sludge installations
    • C02F3/1242Small compact installations for use in homes, apartment blocks, hotels or the like
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00Apparatus for treatment of water, waste water or sewage
    • C02F2201/002Construction details of the apparatus
    • C02F2201/003Coaxial constructions, e.g. a cartridge located coaxially within another
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00Technologies for wastewater treatment
    • Y02W10/10Biological treatment of water, waste water, or sewage
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00Technologies for wastewater treatment
    • Y02W10/30Wastewater or sewage treatment systems using renewable energies
    • Y02W10/37Wastewater or sewage treatment systems using renewable energies using solar energy

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Microbiology (AREA)
  • Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)

Abstract

An air bubble generating device that uses two discs 1 with thin slits 2 arranged that are at an angle to each other and form small air passage holes where the slits cross. The discs may be adapted to fit inside mass produced pipe fittings. The discs may be held by shape features 3, 4 by shape features in each disc which interlock when assembled at the desired angle. The discs may be held at right angles to each other to produce a grid or a mesh 6. The discs may be used may be used within bubble pumps or air diffusers. The pressurised air being used for the bubbles may be supplied by an exterior air pump or a diaphragm pump. The discs may be made from stainless steel. The discs may be used in a sewage treatment or wastewater processing application.

Description

DESCRIPTION
THIS INVENTION relates to household sewage systems typically for processing the foul waste from one to ten person homes. For centuries septic tanks have been used. These are closed vessels where solids in the waste float or sink while contaminated water is drained away to mains drains or drainage fields in the ground. To improve performance and to decontaminate the outlet water, modern systems form compartments either in separate vessels or by baffles in a single vessel such that the action of bacteria can be used to process the waste products. For example in a first chamber 30, shown diagrammatically in figure three, anaerobic bacteria are encouraged to process the solids while in a second connected chamber 31 aerobic bacteria are encouraged by adding blown air from an air pump 32. Typically in a third chamber 33 the water is ready to be discharged in the outflow pipe 35 by the natural action of inflow from the inlet foul drain pipe 34.
This known arrangement can be further improved by the use of internal pipes 42 arranged to take floating debris 36 shown at the water line, and sinking debris 37 from the third chamber 33 back to the first chamber 30. This can be done by two bubble pumps 38 where air is injected in addition to air added to the second chamber 31 by an air diffuser 39.
The air diffuser 39 also causes circulation within the second chamber 31 as illustrated diagrammatically by the arrows 41. In this way chanber 31 encourages aerobic bacteria.
This invention relates to the design and construction of improved bubble pumps, bubble generators and air diffusers.
In the second chamber 31 air is introduced as bubbles 40 and these are preferred to be small bubbles as the surface area of a small bubble is larger in proportion to the volume of air in the bubble. Oxygen in the air transfers to the water at the surface of the bubble. The surface area increases with the square of the bubble radius while the volume increases with the cube. All the bubbles rise to the surface and release air above the water. Therefore small bubbles will better oxygenate the water for a given flow rate of air if small bubbles are generated. With a bubble pump small bubbles are also preferred to lower the density because larger bubbles travel through the water too quickly.
A lower air flow rate is preferred for economy of the pump energy required and this is especially preferred if solar power or wind power are employed to run the air pump.
A typical bubble pump is shown in figure 2 using mass produced pipe components to reduce cost. The pipe is typically 50mm or 1.5 inch nominal plastic pipe but other sizes and materials can be used.
Water with debris is sucked in at 10 in figure 2 into pipe 11 and connected by elbow 12 to tee 13 from where it rises toward elbow 14 thence to a transfer pipe shown by arrow 15.
The flow is generated by the reduced density of the water due to the bubbles 22 generated from pumped air indicated by the arrow 16 going through elbow 20 into a coupling union 17 which is preferred to be a mass produced part for economy.
The water level shown at 21 is above the bubble pump in union 17 providing the weight of water to cause flow in the aerated flow with bubbles 22..
The bubbles are made by holes in the two special discs 18 which are sealed from air leakage by the typical seal 19 in said union 17 and these discs are the subject of this invention.
Known bubble generators made from porous ceramic materials tend to clog up easily in sewage treatment and known rubber sheet generators work well in large sizes but not so well in small sizes. This because large diameters allow the rubber to stretch while small diameters require the rubber to be too thin for robust long life.
This invention relates to the detailed design and construction of the elements 18 in figure 2.
Referring now to figure one, a disc 1 of stainless steel or other suitable material such as ceramic, rubber or other metals, is sized to suit the mass produced union described above. For illustration this can be 63 mm diameter in a typical 50mm nominal union fitting but other standard sizes can be used, such as 1". 1.5", 2" and so on..
By laser cutting, thin slits 2 can be produced accurately in a pattern such as a series of parallel lines. Using a typical laser these can be 0.1 to 0.2 mm wide in for example 0.9mm thick stainless steel. This dimension is smaller than any typical hole made by laser cutting or drilling including the first penetration hole when the laser starts to cut a slit. This detail is important because even 0.5mm diameter holes make large bubbles where smaller bubbles are preferred as explained above. The entry holes of the laser are arranged to be blocked in the preferred arrangement. For example the pattern of slits can be larger than the nominal internal fitting diameter. In the case of 50mm nominal fittings the internal diameter is 40mm and the pattern of slits can be 44mm diameter so that all the laser penetration holes are outside the bore of the fitting.
An identical or similar disc 5 can then be arranged at a rotated angle as shown in figure 1 and placed over the first disc as illustrated in figure 1 at 6., The combination of disc land disc 5 produces small square holes in an array or grid pattern illustrated at 6 and the discs can be retained at an angle, in this case 90 degrees but other angles are possible, by incorporating a slot 4 and a tongue 3 such that a slightly bend tongue 3 on disc 1 can enter slot 4 on disc 5 when both are trapped into a union fitting as described above.
The small square holes thus formed produce small bubbles under a small air pressure typically available from commercially available diaphragm pumps. But the construction of the discs makes them strong enough to withstand much higher air pressures that might be employed for clearing away debris during cleaning operations.
A typical separation between the slits 2 can be 2 mm or other values to produce fewer or more holes.
The invention as described can be used for both bubble pups and air diffusers as described and has the advantage of small size as well as using mass produced plastic pipe parts. This is advantageous because the working parts of a sewage vessel can be conveniently added through small access holes in the vessel and can be arranged to be removable for service. In practice an advantage of this invention is that the same discs can be used in bubble pumps and diffusers providing economy of production and ease of assembly and installion.
According to the present invention small air bubbles can be produced inside mass produced pipe fittings by the use of two touching discs each with slits arranged so that the slits in one disc are at an angle to the second disc thus forming small polygonal holes.
In a preferred embodiment the slits are made by laser cutting.
In a preferred embodiment the discs are held from relative rotation by shape features in each disc which interlock when assembled at the desired angle.
In a further preferred embodiment the discs are held at right angles to each other.
In a further preferred embodiment the two discs are identical to improve the cost of production and the ease of assembly.
The discs can be made of 0.9mm +/-0,8mm thick stainless steel but other materials can be chosen to suit the application.
In a preferred embodiment, the two discs can be used to make bubble pumps and air diffusers for use in sewage treatment plants having two or more vessels or two or more compartments in a single vessel where pressurised air is supplied by an exterior air pump such as a diaphragm pump.
In a further preferred embodiment the sizes of the laser cut discs are chosen to produce conveniently small units which can be added to a sewage system through the top access holes in typical vessels to facilitate installation and service operations.
In a further preffere embodiment the same discs can be used in both bubble pumps and air diffusers.

Claims (9)

  1. CLAIMS1 An air bubble generating device consisting of of two coaxial discs across an air flow pipe, each disc with slits arranged so that the slits in one disc are at an angle to the second disc thus forming small air passage holes where the slits cross.
  2. 2 An air bubble generator as in claim one where the discs are adapted to fit inside mass produced pipe fittings.
  3. 3 An air bubble generating device as in claim 1 in which the slits are made by laser cutting.
  4. 4 An air bubble generating device as in previous claims in which the discs are held from relative rotation by shape features in each disc which interlock when assembled at the desired angle.
  5. An air bubble generating device as in previous claims in which the discs are held at right angles to each other.
  6. 6 An air bubble generating device as in previous claims in which the two discs are identical to improve the cost of production and the ease of assembly.
  7. 7 An air bubble generating device as in previous claims 1 to 5 in which the discs are made of 0.9mm, plus or minus 0.8mm, thick stainless steel.
  8. 8 An air bubble generating device as in previous claims in which the two discs are used to make bubble pumps and air diffusers for use in sewage treatment plants having two or more vessels or two or more compartments in a single vessel where pressurised air is supplied by an exterior air pump such as a diaphragm pump.
  9. 9 An air bubble generating device as in previous claims in which the sizes of the laser cut discs are chosen to produce conveniently small units which can be added to a sewage system through the top access holes in typical vessels to facilitate installation and service operations.An air bubble generating device as in previous claims which is adapted to be used in both bubble pumps and air diffusers within the same sewage treatment plant
GB1905226.5A 2019-04-12 2019-04-12 Improvements to sewage treatment plants Withdrawn GB2582980A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1905226.5A GB2582980A (en) 2019-04-12 2019-04-12 Improvements to sewage treatment plants

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1905226.5A GB2582980A (en) 2019-04-12 2019-04-12 Improvements to sewage treatment plants

Publications (2)

Publication Number Publication Date
GB201905226D0 GB201905226D0 (en) 2019-05-29
GB2582980A true GB2582980A (en) 2020-10-14

Family

ID=66810009

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1905226.5A Withdrawn GB2582980A (en) 2019-04-12 2019-04-12 Improvements to sewage treatment plants

Country Status (1)

Country Link
GB (1) GB2582980A (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992003219A1 (en) * 1990-08-27 1992-03-05 The University Of Newcastle Research Associates Limited Aeration apparatus with diffuser
CN2242887Y (en) * 1995-10-26 1996-12-18 陈庭良 Combined air-diffusing aerator
JP2004195393A (en) * 2002-12-19 2004-07-15 Nomura Denshi Kogyo Kk Gas-liquid mixer
JP2010158631A (en) * 2009-01-08 2010-07-22 Jfe Engineering Corp Diffusion plate
US20110198763A1 (en) * 2010-02-16 2011-08-18 Frankel Thomas E Diffuser membranes with modified electrical properties
US20150246835A1 (en) * 2012-11-19 2015-09-03 Ant21 Co., Ltd Air diffusion device
TW201540674A (en) * 2014-04-21 2015-11-01 Kang Na Hsiung Entpr Co Ltd Gas diffusing disk

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992003219A1 (en) * 1990-08-27 1992-03-05 The University Of Newcastle Research Associates Limited Aeration apparatus with diffuser
CN2242887Y (en) * 1995-10-26 1996-12-18 陈庭良 Combined air-diffusing aerator
JP2004195393A (en) * 2002-12-19 2004-07-15 Nomura Denshi Kogyo Kk Gas-liquid mixer
JP2010158631A (en) * 2009-01-08 2010-07-22 Jfe Engineering Corp Diffusion plate
US20110198763A1 (en) * 2010-02-16 2011-08-18 Frankel Thomas E Diffuser membranes with modified electrical properties
US20150246835A1 (en) * 2012-11-19 2015-09-03 Ant21 Co., Ltd Air diffusion device
TW201540674A (en) * 2014-04-21 2015-11-01 Kang Na Hsiung Entpr Co Ltd Gas diffusing disk

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Holly Technology, October 2016, Fine bubble disc diffuser, Hollyep.com, [online], Available from: http://www.hollyep.com/html/Fine%20Bubble%20Diffusers_Aerators/915 [11/02/2020] *
Zoonar, September 2014, Airing slits, Alamy.com, [online], Available from: https://www.alamy.com/stock-photo-airing-slits-79548337.html *

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)