Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1431—Dissolved air flotation machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/20—Mixing gases with liquids
  • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
  • B01F23/234—Surface aerating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/20—Mixing gases with liquids
  • B01F23/23—Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
  • B01F23/234—Surface aerating
  • B01F23/2341—Surface aerating by cascading, spraying or projecting a liquid into a gaseous atmosphere
  • B01F23/23413—Surface aerating by cascading, spraying or projecting a liquid into a gaseous atmosphere using nozzles for projecting the liquid into the gas atmosphere
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1412—Flotation machines with baffles, e.g. at the wall for redirecting settling solids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1443—Feed or discharge mechanisms for flotation tanks
  • B03D1/1475—Flotation tanks having means for discharging the pulp, e.g. as a bleed stream
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/24—Pneumatic
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/24—Treatment of water, waste water, or sewage by flotation
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F3/00—Biological treatment of water, waste water, or sewage
  • C02F3/02—Aerobic processes
  • C02F3/12—Activated sludge processes
  • C02F3/26—Activated sludge processes using pure oxygen or oxygen-rich gas
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/02—Froth-flotation processes
  • B03D1/028—Control and monitoring of flotation processes; computer models therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1443—Feed or discharge mechanisms for flotation tanks
  • B03D1/1462—Discharge mechanisms for the froth
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2301/00—General aspects of water treatment
  • C02F2301/06—Pressure conditions
  • C02F2301/066—Overpressure, high pressure
• • Y—GENERAL 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
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W10/00—Technologies for wastewater treatment
  • Y02W10/10—Biological treatment of water, waste water, or sewage
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes

Definitions

• the present invention relates to apparatus for producing pressurized gas-saturated liquid, said apparatus comprising a pressure vessel having pressurized gas and liquid delivery means, means for tapping-off gas-saturated liquid, and means for maintaining a predetermined level of liquid in the pressure vessel.
• Flotation plants are used to an ever-increasing extent in the purification of water, both drinking water and sewage water, with the intention of increasing the rate at which the water flows through the purification plant and therewith also enable the size of the necessary tanks and thus the purifica- tion plant as a whole to be reduced.
• the requirements of the end product are essentially unitary and the construction of a purification plant is essentially determined by the nature of the water source or procurement.
• the water source is a lake or river
• coarse particles are normally separated from the water in a screen ⁇ ing chamber, whereafter the water is purified chemically and biologically by adding thereto precipitation and flocculating agents in a flocculating chamber.
• the precipitated particles are then separated from the water, by allowing the particles to settle to the bottom of a sedimentation tank gravitation- ally.
• Different types of particles will have different densities and therewith different settling rates.
• the tank In order for particles of low densities, "light particles”, to have time to settle as the water passes through a sedimentation tank, the tank must be given a large surface area so to provide the long period of time taken for such light parti ⁇ cles to settle.
• Particle separation times can be greatly reduced by flotation processes, in which there are added to the water microscopic air bubbles to which particles or particle floes in the water adhere. These bubbles also contribute in forming particle floes and in maintaining floe coherency.
• the microscopic air bubbles used in flotation processes have a diameter of 30-80 ⁇ m and cannot be produced by simply injecting air directly into water, for instance.
• Microscopic air bubbles intended for drinking water flotation processes are normally produced by releasing pressurized air into clean water from a pressure vessel. The highest possible degree of saturation is sought for in this regard.
• This water is conducted to an inlet for water that has undergone a flocculation process, so-called flocculated water, and which is situated at the bottom of the flotation tank, while maintaining the high pressure of said water, and is there delivered to the flocculated water through separate nozzles or jets which are constructed to generate an instantaneous decrease in pressure to a level at which the air dissolved in the water is released in the form of microscopic bubbles and forms a dispersion of air in the water.
• flocculated water a flocculation process
• Those pressure vessels used to produce pressurized dispersion water that has been saturated with air to the greatest possible extent are normally kept half full with water with the aid of control equipment and associated water level sensor means, and the incoming and outgoing flows of water are located beneath the surface of the water in the pressure vessel. Compressed air is delivered to the air-filled space above the water surface and the vessel has a relatively large size so as to obtain a large surface contact between air and water.
• the diameter of the pressure vessel has been reduced, said pressure vessel often being man high, and the thus reduced air/water contact surface is compensated for by delivering the water through a nozzle provided in the vessel side wall in the air space, through which nozzles the water is injected onto the opposing vessel wall, therewith disintegrating the water jets to some extent.
• the flotation method takes a much shorter time to effect and this shorter throughflow time enables purification plants to be made smaller with retained capacity.
• the object of the present invention is to provide apparatus for producing dispersion liquid having a high degree of gas saturation. Another object is to provide means which combines high capacity with small dimensions.
• Fig. 1 is a schematic, sectioned side view of a conventional ⁇ ly equipped flotation tank
• Fig. 2 is a partially sectioned view of inventive dispersion water producing apparatus.
• Fig. 1 is a schematic, sectioned side view of a conventional ⁇ ly equipped flotation tank referenced generally 1.
• the tank includes an inlet 2 to which water is delivered from a flocculation chamber, not shown.
• the water is caused to flow upwards in the tank 1, by an inclined barrier or baffle 3 mounted inwardly of the inlet 2.
• the pipe 6 functions to deliver air-saturated water, dispersion water, to the flocculated water flowing into the tank through the inlet 2, wherein the pressurized injected dispersion water speeds up movement of the flocculated water.
• the nozzles or jets 5 are constructed to cause the pressure of the dispersion water to be lowered instantaneously, therewith releasing air from the dispersion water and forming micro ⁇ scopic bubbles which as they travel towards the surface of the water collect particles and particle floes and move the major part of these particles and floes quickly to the surface of the water and there form a covering of slime, which is removed and deposited in a slime chute 8 located adjacent the tank wall 9, with the aid of some form of slime scraper 7, or is removed in some other way.
• a filter 10 disposed between the rear side of the baffle 3 and the tank wall 9 and through which the cleaned or purified water passes on its way to a purified water tank (not shown) through an outlet 11.
• Part of the purified water is pumped from the clean water tank at high pressure to the water inlet 13 of a pressure, vessel 12.
• the pressure vessel 12, in which the dispersion water is produced, is supplied with compressed air from a compressor (not shown) through an air intake 14, and the air- saturated water is then fed back to the nozzles 5 mounted in the flotation tank, via an outlet 15 and the distribution pipe 6.
• Fig. 2 is a schematic, partially sectioned view of inventive apparatus for producing dispersion water.
• the apparatus includes a vertically arranged pressure vessel 21 which is comprised of commercially available pipe or tube sections and has the form of an enlargement between an inlet pipe 22 and an outlet pipe 23.
• the inlet pipe 22 opens into a spray arrangement 24 which has the form of an inlet pipe extension and which is closed at its free end.
• the mantle surface of the extension pipe 24 is perforated totally with fine spray holes 25, of which only a few are shown in Fig. 2.
• the pressure vessel 21 is half filled with water and two sensor means 26 provided in the vessel wall send signals to control means (not shown) which decreases or increases the water supply as necessary, or alternatively adjusts the air pressure in the pressure vessel 21.
• Com- pressed air is delivered via the pipe 27 and is controlled by a solenoid valve 28 mounted on the pipe 27.
• a solenoid valve 28 mounted on the pipe 27.
• water is sprayed from the spray means 24 onto the inner wall of the pressure vessel which is thereby covered with a curtain of water to which fresh water is continuously supplied and therewith constantly maintain maximum air absorbency of the curtain.
• the ability of the inventive apparatus to take-up or absorb air is a great improvement on earlier known apparatus designed for this purpose, therewith enabling the dimensions of the inventive apparatus to be substantially reduced in comparison with the dimensions of the known apparatus. For instance, a conventional apparatus having a height of almost 2 m and a diameter of 35 cm can be replaced with inventive apparatus having a height of about 1 m and a diameter of 10 cm.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biotechnology (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Hydrology & Water Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Microbiology (AREA)
• Biodiversity & Conservation Biology (AREA)
• Physical Water Treatments (AREA)
• Cultivation Of Plants (AREA)
• Gas Separation By Absorption (AREA)
• Sorption Type Refrigeration Machines (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Nozzles (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (2)

Family Applications After (1)

Country Status (9)

Cited By (1)

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Citations (1)

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• 1995
  • 1995-01-19 SE SE9500215A patent/SE503895C2/sv not_active IP Right Cessation
• 1996
  • 1996-01-18 PL PL96321465A patent/PL182306B1/pl unknown
  • 1996-01-18 US US08/875,123 patent/US5989437A/en not_active Expired - Fee Related
  • 1996-01-18 AU AU45927/96A patent/AU4592796A/en not_active Abandoned
  • 1996-01-18 CN CN96191494A patent/CN1119285C/zh not_active Expired - Fee Related
  • 1996-01-18 WO PCT/SE1996/000040 patent/WO1996022248A1/en active Application Filing
  • 1996-01-19 AU AU44999/96A patent/AU4499996A/en not_active Abandoned
  • 1996-01-19 WO PCT/SE1996/000050 patent/WO1996022250A1/en active IP Right Grant
  • 1996-01-19 EP EP96901179A patent/EP0789672B1/en not_active Expired - Lifetime
  • 1996-01-19 DE DE69612366T patent/DE69612366T2/de not_active Expired - Fee Related
  • 1996-01-19 AT AT96901179T patent/ATE200272T1/de not_active IP Right Cessation

Patent Citations (1)

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