Classifications

• • 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
  • B01F23/232—Mixing 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
  • B01F23/2322—Mixing 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 using columns, e.g. multi-staged columns
• • 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
  • B01F23/40—Mixing liquids with liquids; Emulsifying
  • B01F23/45—Mixing liquids with liquids; Emulsifying using flow mixing
  • B01F23/454—Mixing liquids with liquids; Emulsifying using flow mixing by injecting a mixture of liquid and gas
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/20—Jet mixers, i.e. mixers using high-speed fluid streams
  • B01F25/21—Jet mixers, i.e. mixers using high-speed fluid streams with submerged injectors, e.g. nozzles, for injecting high-pressure jets into a large volume or into mixing chambers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/30—Injector mixers
  • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
  • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
  • B01F25/3131—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/40—Static mixers
  • B01F25/45—Mixers in which the materials to be mixed are pressed together through orifices or interstitial spaces, e.g. between beads

Definitions

• the present invention concerns a method for dissolving gas in a liquid and a system for doing the same. More specifically, the present invention concerns a flowing liquid into which gas is injected. The liquid flows in a pipe to the top of a mixer. An injector is arranged for the supply of gas to the flow of liquid in the pipe. The gas and liquid flow through the mixer, where the liquid and gas are mixed.
• the present invention may be used for oxygen enrichment of water and may be used in connection with fish farming or farming of other aquatic creatures. For example, the invention may be used in connection with land-based fish farming.
• US 4,171,681 shows a system for fish farming in which water from a lake and a well may be mixed and pumped through a device for supply of oxygen to the water mixture.
• the oxygen-enriched water then proceeds to a land-based farming tank.
• the farming tank At its base, the farming tank has an outlet for draining off water.
• This solution relates to a system for farming as such and does not describe how the oxygen is actually introduced into and dissolved in the water.
• FR 2 750 889 describes an injection device for the introduction of gas into a liquid for use in connection with oxygenation of water for fish farming.
• the injection device comprises a perforated elastic diffusion membrane made of rubber. The gas flows in a spiral around the membrane so that it is brought into contact with a flow of liquid.
• the device is designed to allow small bubbles to be introduced into a flow of liquid without disturbing it greatly.
• a general disadvantage of prior art solutions is that the effectiveness or utilisation of gas may be relatively low, in particular with large gas quantities (when large gas quantities are to be dissolved in water, for example a part flow). This may entail increased costs for gas and/or the need for larger units to be able to treat more water, which, in turn, results in high investment costs.
• the above disadvantages can be avoided with the present invention.
• the present invention it is possible for the oxygen to be mixed well into the water.
• the present invention is also simple, robust and reliable in operation.
• the present invention allows large quantities of gas to be dissolved with good utilisation of the gas.
• Figure 1 shows a system for oxygen enrichment of water which is added to a tank for fish farming in which a separator is placed outside the mixer.
• Figure 2 shows a system for oxygen enrichment of water which is added to a tank for fish farming in which a separator is integrated in the base of the mixer.
• Figure 3 shows an axial section through a mixer equivalent to that shown in Figure 2.
• Figure 4 shows details of the mixer' s inlet in an enlarged scale.
• Figure 1 shows a tank 1 for fish farming in which there is an oxygen-enriched quantity of water 2.
• a jet pipe 3 for the supply of oxygen-enriched water via one or more outlet openings 4, 4' , 4" , 4' " , 4" " , 4" " ' .
• the jet pipe 3 is designed so that it extends down into the tank 1 in a mainly vertical position.
• the equipment for oxygen enrichment of water comprises, among other things, a supply pipe 5 for water, which may consist of a mixture of fresh water and salt water which is introduced at an upstream end of the supply pipe 5 via the inlet pipes 6 and 7 respectively.
• valves 8 and 9 to regulate the quantity of water which flows into the inlet pipes 6 and 7.
• the flow of water may also be shut off completely using the valves.
• the supply pipe 5 is arranged in a vertical position and, at its upper end, it becomes a horizontal part 10 which communicates with an inlet 14 on the top of a mixer 11.
• an injector 12 for injection of oxygen gas from an oxygen supply pipe 13.
• a regulation/shutoff valve 30 may be fitted in the pipe 13 to control the flow of oxygen to the injector 12.
• the mixer 11 may be described as a downward-facing pipe, which may preferably have a greater cross-sectional area than the supply pipe 5.
• the cross-sectional shape may be round or circular. However, other viable cross-sectional shapes may also be used.
• One or more turbulence-initiating elements 15, 15' , 15" , 15" ' , 15" “ , 15” ' " are fitted inside the mixer. They cause the flow through the mixer 11 to be turbulent in such a way that optimal dissolution of oxygen gas in the water is achieved.
• the turbulence-initiating elements used in the example may be designed like a first disc 16 with one or more through holes, where the outer periphery of the disc 16 is in contact with the internal wall surface of the mixer 11.
• Figure 1 shows a disc 16 with one circular, centrally located hole 17.
• a second disc 18 At a short distance from the hole, downstream (below) it, is a second disc 18 of a smaller size than the first disc. It is fitted in such a way that a gap is formed between the internal wall of the mixer 11 and the outer periphery of the disc.
• the discs 16 and 18 may be fitted in a fixed position in the mixer or they may be arranged so that the distance between them can vary (not shown).
• turbulence-initiating element 15 The function of such a turbulence-initiating element 15 is that, when a mixture of liquid and gas flows vertically downwards through the mixer 11 and into such an element 15, the flow will change from being axial to being radial in the element.
• the flow cross-section in the mixer 11 the size of the hole 17 in the first disc and the size of the second disc 18, as well as the distance between the discs, it will be possible to initiate a change in speed in the flowing medium over the element 15 in addition to the relatively extensive change in direction of flow which occurs here.
• the separator 22 is to separate surplus gas/oxygen from the mixture that comes from the mixer 11.
• the mixture of water and oxygen gas which comes from the mixer 11 in this example may be supersaturated with oxygen, i.e. it contains more oxygen than can be dissolved in water.
• the separator 22 will comprise both a liquid phase 23 and a gaseous phase 24.
• the gaseous phase which will generally consist of oxygen, is taken out of the top of the separator 22 via a return pipe 25, which may be fitted with a shutoff/regulation valve 26.
• the return pipe 25 conducts surplus gas/return gas back to the injector 12 so that it will follow the flow of water into the mixer 11 again together with a larger or smaller quantity of oxygen from the pipe 13.
• the return gas may be conducted back to the mixer 11 via a return pipe connected to its own injector, i.e. without being connected to the pipe 13 and injector 12.
• FIG. 2 shows a system for oxygen enrichment of water which is added to a tank 101 for fish farming in which a gas/liquid separator 122 is integrated in the base of a mixer 111.
• a jet pipe 103 for the supply of oxygen-enriched water via one or more outlet openings 104, 104' , 104" , 104' " , 104" " and 104
• the system comprises a supply pipe 105 for water, which may consist of a mixture of fresh water and salt water which is introduced at an upstream end of the supply pipe 105 via the inlet pipes 106 and 107 respectively.
• a supply pipe 105 for water which may consist of a mixture of fresh water and salt water which is introduced at an upstream end of the supply pipe 105 via the inlet pipes 106 and 107 respectively.
• valves 108 and 109 to regulate the quantity of water which flows into the inlet pipes 106 and 107 or to shut off the flow of water completely.
• the supply pipe 105 is, as shown, arranged in a vertical position and, at its upper end, it becomes a horizontal part 110 which communicates with an inlet 114 on the top of the mixer 111.
• an injector 112 for injection of oxygen gas from an oxygen supply pipe 113.
• a regulation/shutoff valve 130 may be fitted in the pipe 113 to control the flow of oxygen to the injector 112.
• Figure 3 shows an axial section through a mixer 111 with an integrated separator 122, as shown in Figure 2. It can be seen that the design of the separator' s outlet differs somewhat from that shown in Figure 2.
• One or more turbulence-initiating elements 115, 115' , 115" , 115' " , 115” " are fitted inside the mixer. They cause the flow through the mixer 111 to be turbulent in such a way that optimal dissolution of oxygen gas in the water is achieved.
• the turbulence-initiating elements used in the example may be designed like a first disc 116" with one or more through holes, where the outer periphery of the disc 116" is in contact with the internal wall surface of the mixer 111.
• the figure shows a disc 116" with one circular hole which, together with a return pipe 125, forms a centrally located annulus 117" .
• the pipe 125 may be coaxially mounted in relation to the hole in the disc 116" and will be described in further detail later.
• a second disc 118" At a short distance from the annulus 117" , downstream from (below) it, is a second disc 118" of a smaller size than the first disc. It is fitted in such a way that a gap is formed between the internal wall of the mixer 111 and the outer periphery of the disc.
• the disc 118" as shown in the figure, is designed with a central hole through which the pipe 125 passes, preferably forming a tight seal against the surface of the hole.
• the discs 116" and 118" may be fixed or variable, equivalent to that described for the mixer 11 shown in Figure 1.
• the separator 122 which is located in the base of the mixer 111 , may have the same diameter as or a larger diameter than the rest of the mixer 111.
• the size is dimensioned on the basis of requirements so that the speed of the water downwards in a vertical direction is low enough to allow the gas bubbles to rise.
• the separated gas is returned to the top of the mixer 111 via the vertical return pipe 125 inside the mixer 111 and out through a dissolution element 131.
• the return pipe 125 expediently has a collection element 126 to collect gas bubbles in towards the inlet.
• the collection element may expediently be created by mounting an annular flange 127 on the lower side of the lowest disc 118" " in the turbulence-initiating element 115' " ' .
• the dissolution element 131 is designed so that the water which flows into the mixer is distributed radially and out over the lowest disc in the element 115.
• the dissolution element 131 is designed with holes on the side (all around it) through which the gas escapes.
• the dissolution element 131 has the function that it prevents incoming water from running down through the inlet where the return gas comes up.
• Surplus gas/return gas flows up through the return pipe 125, among other things because the gas bubbles have buoyancy (bubble buoyancy) and also because of the difference in pressure (height) between the top and bottom of the pipe.
• the liquid which flows past the opening in the dissolution element will cause a certain ejector effect.
• the liquid phase from the separator 122 is conducted from an outlet 119 (which may be in the base or on the side, etc., of the separator, depending on the conditions) and on to the farming tank 101 via a pipe 120.
• the outlet may consist of a pipe 132 which is placed across the mixer 111 and runs through it. One end of the pipe 132 may be blanked off and the other connected to the farming tank 101.
• the pipe 132 has a downward-facing recess 133 in its wall, which allows water to flow into the pipe from the separator 122.
• the pipe 120 is fitted with a manual or automatic regulation valve 129 which maintains the desired operating pressure in the mixer and meters the correct quantity of water.
• the expression liquid phase is used here for practical reasons even though the liquid may be saturated with oxygen gas. With the present invention, the gas dissolved in the liquid after the separator 122 will be dissolved as molecular oxygen without significant content of visible gas bubbles.
• Figure 4 shows details of the mixer' s inlet 114 in an enlarged scale.
• the turbulence- initiating element 115 has a first disc 116 and a second disc 118.
• the dissolution element 131 is mounted centrally in relation to the disc 118 and has an inlet opening 135 which communicates with the return pipe 125 ( Figure 3).
• the dissolution element 131 may be designed with one or more outlet openings 134, 134' in a mainly radial direction and have a rotationally symmetrical form so that the flow of liquid is distributed evenly in a radial direction over the disc 118.
• the system may be used in connection with different liquids/liquid mixtures to dissolve different gases/gas mixtures.
• gases other than oxygen such as CO 2 or air, may be dissolved.
• a mixture of C0 2 and 0 2 can be dissolved in water for the stunning of fish before slaughter.
• Another example related to fish farming is to dissolve a mixture of CO and an inert gas in water to be used in a bleeding off tank for slaughtered fish to avoid browning of the fish' s gills.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Dispersion Chemistry (AREA)
• Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)
• Farming Of Fish And Shellfish (AREA)
• Fertilizers (AREA)
• Medicines Containing Antibodies Or Antigens For Use As Internal Diagnostic Agents (AREA)
• Silicon Compounds (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Sampling And Sample Adjustment (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (9)

Cited By (2)

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Citations (4)

• 2001
  • 2001-09-07 NO NO20014375A patent/NO315029B1/no not_active IP Right Cessation
• 2002
  • 2002-08-30 DE DE60203722T patent/DE60203722T2/de not_active Expired - Lifetime
  • 2002-08-30 AT AT02756000T patent/ATE293008T1/de active
  • 2002-08-30 DK DK02756000T patent/DK1423182T3/da active
  • 2002-08-30 PT PT02756000T patent/PT1423182E/pt unknown
  • 2002-08-30 ES ES02756000T patent/ES2240783T3/es not_active Expired - Lifetime
  • 2002-08-30 WO PCT/NO2002/000306 patent/WO2003022413A1/en not_active Application Discontinuation
  • 2002-08-30 EP EP02756000A patent/EP1423182B1/en not_active Expired - Lifetime
  • 2002-09-06 MY MYPI20023344A patent/MY128943A/en unknown

Patent Citations (4)

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