EP1473986A2 - Megaströmungssystem - Google Patents
MegaströmungssystemInfo
- Publication number
- EP1473986A2 EP1473986A2 EP03703000A EP03703000A EP1473986A2 EP 1473986 A2 EP1473986 A2 EP 1473986A2 EP 03703000 A EP03703000 A EP 03703000A EP 03703000 A EP03703000 A EP 03703000A EP 1473986 A2 EP1473986 A2 EP 1473986A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- water
- conduit
- flow path
- arrangement
- aeration
- 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- Withdrawn
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 127
- 238000005273 aeration Methods 0.000 claims abstract description 73
- 244000144974 aquaculture Species 0.000 claims abstract description 41
- 238000009360 aquaculture Methods 0.000 claims abstract description 39
- 238000005086 pumping Methods 0.000 claims description 23
- 239000007787 solid Substances 0.000 claims description 15
- 230000001105 regulatory effect Effects 0.000 claims description 10
- 238000000926 separation method Methods 0.000 claims description 10
- 230000000284 resting effect Effects 0.000 claims description 6
- 238000004140 cleaning Methods 0.000 claims description 5
- 238000002347 injection Methods 0.000 claims description 4
- 239000007924 injection Substances 0.000 claims description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 10
- 229910052760 oxygen Inorganic materials 0.000 description 10
- 239000001301 oxygen Substances 0.000 description 10
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 238000007689 inspection Methods 0.000 description 6
- 239000002028 Biomass Substances 0.000 description 5
- 229910002092 carbon dioxide Inorganic materials 0.000 description 4
- 239000001569 carbon dioxide Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 241000251468 Actinopterygii Species 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 241000894007 species Species 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000001965 increasing effect Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000036284 oxygen consumption Effects 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000013049 sediment Substances 0.000 description 1
- 235000015170 shellfish Nutrition 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
- A01K63/00—Receptacles for live fish, e.g. aquaria; Terraria
- A01K63/04—Arrangements for treating water specially adapted to receptacles for live fish
- A01K63/042—Introducing gases into the water, e.g. aerators, air pumps
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
- A01K63/00—Receptacles for live fish, e.g. aquaria; Terraria
- A01K63/04—Arrangements for treating water specially adapted to receptacles for live fish
Definitions
- the present invention relates to an aquaculture system and, in particular, it concerns a system for increasing aquaculture biomass density by aeration using atmospheric air only.
- the most wide spread solution is to use oxygen enrichment from a liquid oxygen source or from an oxygen generator.
- the high concentration of the source allows super saturation of oxygen and thus allows a low rate of water recirculation.
- Bio-density is limited due to the narrow band available for oxygen introduction between saturation and the minimal concentration required for the well being of the reared species. Typically the minimum concentration needed is not far from saturation (1-3 parts per million difference). Bio-density is also limited due to the maximum velocity and turbulence created by such apparatus, limiting its use and creating a maximum density barrier derived from the rate of oxygen consumption and the maximum allowable speed and turbulence. Therefore, there is a need for a system to surpass the density limitation for an aerated recirculated aquaculture system
- the present invention is an aerated recirculated aquaculture system and method of operation thereof.
- an aerated recirculated aquaculture system comprising: (a) a culture tank for housing live aquaculture, the culture tank defining a first flow path; and (b) an aeration and circulation system including an aeration device configured to aerate water, the aeration device defining a second flow path, the first flow path and the second flow path at least partially defining a substantially closed flow path sequentially passing through the culture tank and the aeration device, the aeration and circulation system being configured to circulate the water around the substantially closed flow path.
- the aeration device includes an airlift pump having a dispensing arrangement and a conduit, the conduit having a top opening and a bottom opening, the dispensing arrangement having a plurality of holes configured for enabling injection of air into the water causing a plurality of bubbles to form in the conduit, the holes substantially covering a majority of the dispensing arrangement, the dispensing arrangement having at least one opening configured to allow passage of the water through the dispensing arrangement, such that a majority of the water flowing in the second flow path passes through the dispensing arrangement between a majority of the holes.
- the conduit is configured to direct momentum from the upward flow of the water in the conduit into the first flow path of the culture tank.
- the culture tank has an internal bottom surface; and (b) at least part of the bottom opening of the conduit is disposed lower than any part of the internal bottom surface.
- the conduit has a substantially rectangular cross-section.
- conduit tapers towards the top opening.
- holes are spaced substantially evenly among the dispensing arrangement.
- the airlift pump includes an adjustable choke configured to regulate the rate of water flow in the conduit, thereby regulating the amount of aeration of the water.
- the airlift pump includes an air dispensing arrangement disposed externally to the conduit, the dispensing arrangement being configured to regulate the rate of water flow in the conduit, thereby regulating the amount of aeration of the water.
- the top opening is substantially wholly disposed below a resting level of the water within the culture tank.
- the culture tank has a first sloping internal bottom surface adjacent to the top opening of the conduit and a second sloping internal bottom surface, the first sloping internal bottom surface being steeper than the second sloping internal bottom surface.
- a separation arrangement disposed between the culture tank and the aeration device substantially at the end of the first flow path, the separation arrangement being configured to filter water leaving the culture tank to prevent clogging of the aeration device.
- a bottom collector having a collection opening, the culture tank having an internal bottom surface, the collection opening being disposed adjacent to the internal bottom surface such that, in operation a bottom layer of contaminated water flowing through the first flow path is removed from the culture tank via the collection opening.
- the bottom collector has a collection container configured for collecting the bottom layer; and (b) the bottom collector has a pumping arrangement configured to remove the bottom layer from the collection container, the pumping arrangement being configured to pump at a rate which is sufficient to ensure that the bottom layer is removed from the first flow path via the collection opening.
- the collection container has an at least partially slanted bottom surface configured to cause solids to collect near to the pumping arrangement.
- the pumping arrangement operates using an airlift apparatus.
- an airlift pump system comprising: (a) a conduit having a top opening and a bottom opening, the conduit defining a flow path from the bottom opening to the top opening; and (b) a dispensing arrangement having a plurality of holes configured for enabling injection of air into the water causing a plurality of bubbles to form in the conduit, the holes substantially covering a majority of the dispensing arrangement, the dispensing arrangement having at least one opening configured to allow passage of the water through the dispensing arrangement, such that a majority of the water flowing in the flow path passes through the dispensing arrangement between a majority of the holes.
- the conduit has a substantially rectangular cross-section.
- the conduit tapers towards the top opening.
- the holes are spaced substantially evenly among the dispensing arrangement.
- an adjustable choke configured to regulate the rate of water flow in the conduit, thereby regulating the amount of aeration of the water.
- an air dispensing arrangement disposed externally to the conduit, the dispensing arrangement being configured to regulate the rate of water flow in the conduit, thereby regulating the amount of aeration of the water.
- a cleaning system for cleaning contaminated water in a tank, the tank being configured for having the water flow therein in a defined flow path, the tank having an internal bottom surface, the system comprising: (a) a collection opening disposed adjacent to the internal bottom surface of the tank configured for removing a bottom layer of contaminated water flowing through the tank; a collection container for collecting the bottom layer therein; and (b) a pumping arrangement configured to remove the bottom layer from the collection container, the pumping arrangement being configured to pump at a rate which is sufficient to ensure that the bottom layer is removed from the tank via the collection opening.
- the collection container has an at least partially slanted bottom surface configured to cause solids to collect near to the pumping arrangement.
- the pumping arrangement operates using an airlift apparatus.
- Fig. 1 is a plan view of an aerated recirculated aquaculture system that is constructed and operable in accordance with a preferred embodiment of the present invention
- Fig. 2 is a cross-section view of the aerated recirculated aquaculture system of Fig. 1 through line A-A;
- Fig. 3 is a cross-sectional view of the aerated recirculated aquaculture system of Fig. 1 through line B-B;
- Fig. 4 is a plan view of an aerated recirculated aquaculture system that is constructed and operable in accordance with an alternate embodiment of the present invention
- Fig. 5 is a top view of a dispensing arrangement for use with the aerated recirculated aquaculture system of Fig. 1 ;
- Fig. 6 is a top view of an adjustable choke for use with the aerated recirculated aquaculture system of Fig. 1 ;
- Fig. 7a is a cross-sectional view of the aerated recirculated aquaculture system of Fig. 1 that is constructed and operable in accordance with a most preferred embodiment of the present invention;
- Fig. 7b is a plan view of the aeration tank in accordance with the most preferred embodiment of Fig. 7a;
- Fig. 8 is a cross-section view of the aerated recirculated aquaculture system of
- the present invention is an aerated recirculated aquaculture system construction and method of operation thereof.
- the principles and operation of an aerated recirculated aquaculture system according to the present invention may be better understood with reference to the drawings and the accompanying description.
- Fig. 1 is a plan view of an aerated recirculated aquaculture system 10 that is constructed and operable in accordance with a preferred embodiment of the present invention.
- Fig. 2 is a cross-section view of aerated recirculated aquaculture system 10 of Fig. 1 through line A-A.
- Fig. 3 is a cross-sectional view of aerated recirculated aquaculture system 10 of Fig. 1 through line B-B.
- Aerated recirculated aquaculture system 10 includes a culture tank 12 for housing aquaculture species, for example, fish and shellfish and an aeration tank 14. Culture tank 12 defines a flow path 16.
- Aeration tank 14 includes an aeration and circulation system 18 which includes an aeration device 20 configured to aerate the water in culture tank 12.
- Aeration device 20 is formed from four airlifts 22. It will be appreciated by one ordinarily skilled in the art that the number of airlifts included within aeration device 20 will depend on various design factors. It is generally possible to have a single airlift within aeration device 20. However, the division of aeration device 20 into a number of airlifts allows the operator to employ part of the battery of airlifts when the biomass is small and employ more of the airlifts as the biomass and therefore the demand for aeration grows. In this manner energy is saved because supply follows more closely the demand.
- Airlifts 22 aerate the water by adding oxygen and removing carbon dioxide.
- Aeration device 20 defines a flow path 24.
- the closed flow path is described as “substantially closed”, in that approximately 10% of the flow is removed to undergo a nitrification cycle and approximately 1 % of the main flow is removed as waste solids (see reference to inspection tray 33 below).
- the closed flow path is described as "sequentially passing through culture tank 12 and aeration tank 14".
- Aeration and circulation system 18 is configured to circulate the water around the substantially closed flow path.
- Each of airlifts 22 performs this circulation function. Airlifts 22 are described in more detail with respect to Fig. 5.
- Culture tank 12 has a sloping internal bottom surface 28 adjacent to airlifts 22 and a sloping internal bottom surface 30 in the remainder of culture tank 12. Sloping internal bottom surface 28 is steeper than sloping internal bottom surface 30. Sloping internal bottom surface 28 encourages a progressive integration of the "bubbly flow” leaving airlifts 22 into the slow flowing water in culture tank 12.
- the rate of flow in culture tank 12 in the region of sloping internal bottom surface 30 is typically 10 centimeters per second allowing uniform substantially laminar flow of the water. The velocity is kept at a convenient speed for the reared species. Sloping internal bottom surface 30 encourages solid waste materials to travel toward a bottom collector 32 which is disposed adjacent to sloping internal bottom surface 30 near to the end of flow path 16. Bottom collector 32 removes a bottom layer of contaminated water, containing waste materials.
- the contaminated water is sent for processing via an inspection tray 33 which collects the heaviest solids, such as uneaten food pellets, allowing information gathering and decision making regarding care of the aquaculture species, for example, by adjusting the feeding regime. Water and sediment are released from inspection tray 33 for further processing.
- a separation arrangement 34 typically a separating grill or grid is disposed between culture tank 12 and aeration tank 14, substantially at the end of flow path 16. Separation arrangement 34 is configured to filter water leaving culture tank 12 to prevent clogging of aeration device 20. Separation arrangement 34 is tilted towards aeration tank 14 to encourage any items which might block separation arrangement 34, such as dead fish, to rise to the top of separation arrangement 34, thereby enabling easy removal.
- the arrangement of the closed loop of culture tank 12 and aeration tank 14 ensures that the most oxygenated and degassed water is enters culture tank 12 and the least oxygenated and carbon dioxide saturated water returns to aeration tank 14. Thus, creating the highest concentration difference for the airlift operation enhancing the gas transfer efficiency of airlifts 22.
- the speed of the water flowing in culture tank 12 depends on the design of airlifts 22 as well as the number of airlifts 22 being operated. Heavy solids tend to sink fast to the bottom of culture tank 12. Therefore, the water flow rate and the slope of sloping internal bottom surface 30 need to be configured to ensure that solids do not accumulate in the quieter zones of culture tank 12. It is very important to avoid solid accumulation because solids release undesirable substances into the water. However, it will be apparent to those ordinarily skilled in the art that the speed of the water flowing in culture tank 12 will depend upon the minimum cleaning velocity needed to ensure that solids are pushed along sloping internal bottom surface 30 towards bottom collector 32 versus fish comfort and gas transfer efficiency.
- FIG. 4 is a plan view of an aerated recirculated aquaculture system 36 that is constructed and operable in accordance with an alternate embodiment of the present invention.
- Aerated recirculated aquaculture system 36 includes two culture tanks 38 and two aeration tanks 40. Each aeration tank 40 includes an aeration and circulation system 42.
- Aerated recirculated aquaculture system 36 also includes a bottom collector 44 and a separation arrangement 46 disposed in each culture tank 38. Culture tanks 38 and aeration tanks 40 define a closed flow path 48.
- Airlift 22 is a high efficiency airlift, which is a development of the well- known Airlift pump.
- An airlift pump uses compressed air introduced at the bottom of the pump creating a mixture of air bubbles and water, which is lighter than water. This creates the lifting effect. It has been shown by several researchers, amongst them Timmons & Reinemann, that an airlift pump is efficient as long as the gas to liquid ratio is below 25%. This creates a phenomenon called "bubbly flow". The same researchers recommend that the ratio between diameter of the pump and its length is smaller than 1 : 15. Since tanks in normal aquaculture facilities are rather shallow the usual airlift diameter is limited to about 3 inches, thereby limiting the output flow.
- the current invention is based on a high flow rate of newly aerated water through aeration tank 14.
- the flow provides the needed dissolved oxygen while keeping the minimum concentration above a predefined concentration.
- the desired flow is therefore the total oxygen flux needed divided by the concentration span available. Since a typical oxygen flux in aquaculture is a few hundred grams per ton of biomass per hour, the typical water flow needed is a few hundred cubic meters per hour per ton of biomass. Hence, the typical airlift application should have a flow capacity measured in thousands of cubic meters per hour. Such a flow rate is not practical with a conventional airlift which is typically limited to 3 inches in diameter. Many hundreds of conventional airlifts would be necessary to provide this flow rate.
- airlifts 22 of the current invention have additional features which enable them to overcome the 1 : 15 ratio, thereby providing a high efficiency airlift for commercial aquaculture.
- Each airlift 22 has a dispensing arrangement 50 and a conduit 52.
- Conduit 52 has a top opening 54 and a bottom opening 56.
- Dispensing arrangement 50 is disposed within conduit 52 near to bottom opening 56 or below conduit 52 near to bottom opening 56.
- Fig. 5 which is a top view of dispensing arrangement 50.
- Dispensing arrangement 50 has a dispensing grill 58, which is formed from a central airway 60 supplying compressed air to a plurality of secondary airways 62.
- the major surfaces of dispensing grill 58 are approximately 45cm long by 35 cm wide.
- Secondary airways 62 have a plurality of air-dispensing holes 64 through which air is injected into the water causing bubbles to form in conduit 52.
- Secondary airways 62 are typically formed from a rigid material such as a hard plastic. Holes 64 typically have a diameter of half a millimeter.
- secondary airways 62 are formed from a flexible material which is supported by a rigid support structure, holes 64 being formed as very small slits through the surface of the flexible material. When the holes are formed as slits in the flexible material they general remain unclogged. In accordance with this preferred embodiment of the present invention, there are approximately 2000 holes 64 per dispensing grill 58. Holes 64 are substantially evenly spaced on dispensing grill 58.
- the typical spacing between holes 64 is in the order of the expected bubble diameter. It is not desirable to enhance coalescence of the bubbles. However, it is desirable to maximize the contact surface area between the air and the water. Therefore, the minimum practical distance between holes 64 is typically about 6 mm, which is 20% to 50% more than an expected bubble diameter.
- holes 64 are configures to cover a majority of dispensing grill 58.
- the term "covering" means at least 3,000 holes 64 per square meter. If holes 64 are not all disposed on a plane which is perpendicular to flow path 24, then the gaps between holes 64 should be assessed by projecting holes 64 onto a plane which is perpendicular to flow path 24. .
- a plurality of openings 66 between secondary airways 62 allows the passage of water through dispensing grill 58, while holes 64 located on the secondary airways 62 supply the air bubbles at even distances.
- the width of each opening 66 is approximately the same as the width of each secondary airway 62. Both water and bubbles interweave to form a substantially uniform mixture that gradually increases its velocity towards the outlet.
- a majority, typically almost 100%, of the water flowing into airlift 22 passes through openings 66 of dispensing grill 58 between a majority, typically almost 100%, of holes 64.
- Dispensing grill 58 is typically detachable for maintenance purposes, allowing easy access to the holes 64, sparing the need to remove the whole of airlift 22 from the water.
- Dispensing arrangement 50 includes a water evacuation port 68 (Fig. 2), which allows fast water evacuation from central airway 60 and secondary airways 62.
- the evacuation port is located below the level of holes 64 so that air will not escape through water evacuation port 68. Keeping the airways open allows even distribution of air through dispensing grill 58 creating an even "bubbly flow".
- the size and number of holes 64 is configured to ensure that water is evacuated from the airways without air escaping through water evacuation port 68.
- Water evacuation port 68 has a one-way valve which only allows water to exit dispensing arrangement 50 via water evacuation port 68. This feature is important in order to prevent soiled water from entering the airways when airlift 22 is inoperable and clogging holes 64 when pumping is resumed. Water evacuation port 68 extends almost to the bottom of aeration tank 14 to ensure even distribution of air in the system. Bottom opening 56 is typically wholly or at least partially disposed lower than any part of sloping internal bottom surface 30. Therefore, aeration tank 14 is deeper than culture tank 12. This increased depth allows an efficient operation of airlifts 22. Conduit 52 has a substantially rectangular cross-section.
- conduit 52 allows an increase in the flow of water in airlift 22 without having to increase the length of conduit 52, which is a common requirement with prior art round cross-section airlifts.
- the rectangular cross-section also enables effective space utilization.
- conduit 52 tapers towards top opening 54.
- the change in cross section area from bottom opening 56 to top opening 54 allows a gradual increase of flow speed inside airlift 22 saving friction losses especially at bottom opening 56, where introduced water undergoes a sudden change in speed.
- Conduit 52 is configured to direct momentum from the upward flow of the water in conduit 52 into flow path 16 of culture tank 12, by bending conduit 52 such that top opening 54 faces culture tank 12.
- Adjustable choke 70 is disposed within conduit 52 below and adjacent to dispensing grill 58. Adjustable choke 70 is configured to regulate the rate of water flow in conduit 52, thereby regulating the amount of aeration of the water. Adjustable choke 70 is formed as a grill having two side-supports 72 and a plurality of central elongated members 74.
- the width and spacing of elongated members 74 is configured to match the width and spacing of openings 66 of dispensing grill 58 (Fig. 5).
- Adjustable choke 70 is disposed, such that the direction of elongation of elongated members 74 is parallel to the direction of elongation of openings 66. Therefore, lateral movement of adjustable choke 70 with respect to dispensing grill 58 is able to control the water flow rate through conduit 52. It will be appreciated by those skilled in the art that arrangements performing a similar function to adjustable choke 70 can be disposed anywhere in conduit 52.
- Fig. 7a is a cross-sectional view of aerated recirculated aquaculture system 10 of Fig. 1 along line A-A that is constructed and operable in accordance with a most preferred embodiment of the present invention.
- top opening 54 of conduit 52 is substantially wholly disposed below a resting level of the water within culture tank 12.
- a “resting level” of the water is defined as the water level within culture tank 12 when aeration and circulation system 18 is inoperable and there is no “bubbly flow” creating different water levels in aerated recirculated aquaculture system 10.
- Airlift 22 in accordance with this most preferred embodiment does not have to do work to raise the water above the resting level and thereby saving lifting energy. Additionally, in accordance with this most preferred embodiment the cross-section of conduit 52 typically does not taper, as the reasons described above regarding tapering of the cross-section of conduit 52 with respect to Fig. 5 are generally not applicable here. Reference is also made to Fig. 7b, which is a plan view of aeration tank 14 in accordance with this most preferred embodiment.
- an air dispensing arrangement 90 is disposed externally to conduit 52 within aeration tank 14. Air dispensing arrangement 90 is configured to regulate the rate of water flow in conduit 52, thereby regulating the amount of aeration of the water.
- Air dispensing arrangement 90 has a main airway 92, which supplies air to secondary airways 94.
- Secondary airways 94 have a plurality of holes (not shown) configured to inject air into the water in aeration tank 14 thereby creating bubbles which make the water lighter, reducing the density of the water outside of airlifts 22.
- This reduction in water density reduces the up flow effect in airlift 22, denoted by arrow 98, created by dispensing grill 58 of airlift 22. Therefore, the resulting speed of the water which is rising in airlift 22 is reduced by air dispensing arrangement 90. Therefore, air-dispensing arrangement 90 performs a similar function as adjustable choke 70 (Fig. 6) without the disadvantages of adjustable choke 70.
- Adjustable choke 70 limits the water flow by a sudden decrease in cross-sectional area which increases the water speed locally and thereby resulting in lost energy.
- the air added to the water by air dispensing arrangement 90 is also used to aerate the water in airlifts 22. Therefore, air- dispensing arrangement 90 is a very efficient device for reducing the upward flow in airlifts 22.
- the water and air mixture inside conduit 52 should be lighter than the mixture outside of conduit 52 in aeration tank 14 to ensure that water still rises in conduit 52. Therefore, the number of holes per unit area of air dispensing arrangement 90 should be less than the number of holes per unit area of dispensing grill 58.
- Air dispensing arrangement 90 is disposed at the same level as dispensing grill 58 within aeration tank 14. Air dispensing arrangement 90 is supported by a plurality of support legs 100. It should be noted that the whole of air dispensing arrangement 90 should be operated even when only one or some of airlifts 22 are operable. This is to ensure that the desired density ratio of air to water outside of the operable airlifts 22 is maintained so that the retention time of the water in the operable airlifts 22 is independent of the number of airlifts 22 in operation.
- top opening 54 of conduit 52 includes one or more hinged flaps 104 made of buoyant material. Hinged flaps 104 automatically close top opening 54 when there is no flow from conduit 52.
- FIG. 8 is a cross-section view of aerated recirculated aquaculture system 10 of Fig. 1 through line C-C showing bottom collector 32.
- FIG. 3 Bottom collector 32 has a collection opening 76 which is disposed adjacent to the lowest section of sloping internal bottom surface 30.
- Collection opening 76 is formed by an opening between collection container 78 and a collecting door 86 which is attached to the top of collection container 78 by at least one hinge 88.
- Collecting door 86 is typically a rectangular plate spanning substantially the whole width of sloping internal bottom surface 30. Collecting door 86 is made of a buoyant material in order to keep collecting door 86 open during normal operation. A calibrated device (not • shown) ties down collecting door 86 to maintain the dimensions of collection opening 76. The height of collection opening 76 is typically set to about 1 centimeter above sloping internal bottom surface 30. Therefore, bottom collector 32 operates like a carpenter's wood plane, cutting off a layer of material which moves against an inclined wide blade. As described above, collecting door 86 is attached to collection container 78 by a hinge, allowing easy access to collection container 78 for inspection and maintenance.
- a pumping arrangement 80 removes the contents of collection container 78 to inspection tray 33 (Fig. 1). Pumping arrangement 80 pumps at a rate which is sufficient to ensure that the bottom layer of contaminated water flowing through flow path 16 is removed via collection opening 76. It should be noted that the pumping rate needs to be sufficient to remove the heavy solids traveling near the bottom of culture tank 12. Generally, the required pumping rate is equal to or higher than the product of the average cross-sectional water velocity in flow path 16 close to bottom collector 32 and the area of collection opening 76. Pumping arrangement 80 operates using an airlift apparatus including a conduit 82 and an air dispensing arrangement 84.
- the holes of dispensing arrangement 84 are disposed at the same level as holes 64 of dispensing grill 58 thereby allowing the use of a single compressed air supply. Therefore, a single compressor services each aerated recirculated aquaculture system 10 and an array of aerated recirculated aquaculture systems 10 with a single engine.
- Collection container 78 has a partially sharply slanted bottom surface, typically at least a 40% gradient, configured to cause solids to collect near to the inlet of pumping arrangement 80.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Environmental Sciences (AREA)
- Marine Sciences & Fisheries (AREA)
- Animal Husbandry (AREA)
- Biodiversity & Conservation Biology (AREA)
- Farming Of Fish And Shellfish (AREA)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US35945102P | 2002-02-15 | 2002-02-15 | |
US359451P | 2002-02-15 | ||
PCT/IL2003/000112 WO2003067966A2 (en) | 2002-02-15 | 2003-02-13 | Mega flow system |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1473986A2 true EP1473986A2 (de) | 2004-11-10 |
EP1473986A4 EP1473986A4 (de) | 2008-03-12 |
Family
ID=27734767
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP03703000A Withdrawn EP1473986A4 (de) | 2002-02-15 | 2003-02-13 | Megaströmungssystem |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1473986A4 (de) |
JP (1) | JP2005538688A (de) |
KR (1) | KR20040096565A (de) |
AU (1) | AU2003206116B2 (de) |
WO (1) | WO2003067966A2 (de) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101056657B1 (ko) * | 2009-09-03 | 2011-08-12 | 이장수 | 밀물가두리 |
CN107258634A (zh) * | 2017-07-07 | 2017-10-20 | 江苏省海洋水产研究所 | 兼具滩涂贝苗培育和养殖水处理的系统及运行方法 |
KR102150694B1 (ko) | 2018-06-05 | 2020-09-01 | 씨와이에이지 주식회사 | 무약품 순환식 양식 장치 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1592085A (en) * | 1977-08-26 | 1981-07-01 | Fisons Ltd | Fish rearing apparatus |
WO1990003109A1 (en) * | 1988-09-22 | 1990-04-05 | Sinvent As | Device for tanks for the rearing of aquatic organisms |
DE19521037A1 (de) * | 1995-06-09 | 1996-12-12 | H J Dipl Ing Schultze | Becken zur Fischzucht |
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US893625A (en) * | 1907-10-21 | 1908-07-21 | Jean Heuscher | Means for producing circulation in liquid-tanks. |
US3638616A (en) * | 1970-09-14 | 1972-02-01 | William Jeter Carmouche | Fish-growing aquarium |
FR2473243A1 (fr) * | 1980-01-08 | 1981-07-10 | Saint Gobain Vitrage | Vitrage chauffant et dispositif de fabrication |
BE888607A (fr) * | 1980-04-29 | 1981-10-28 | Venturator Ltd | Dispositifs pour gazeififier des liquides et installations de traitement comprenant de tels dispositifs, |
US4481905A (en) * | 1983-07-01 | 1984-11-13 | Fonseca Oscar O | Aquarium with improved aerator and purifier |
US4915059A (en) * | 1987-05-12 | 1990-04-10 | Fisheries Engineering Research And Development Co., Inc. | Raceway culturing of fish |
JPH0331029U (de) * | 1989-07-27 | 1991-03-26 | ||
US5066394A (en) * | 1990-07-30 | 1991-11-19 | Harrison Mark R | Aquarium aeration and recycling apparatus |
US5139659A (en) * | 1991-01-11 | 1992-08-18 | Michael Scott | Aquarium air-lift water pump, aerator, and filter |
DE4103402C1 (de) * | 1991-02-05 | 1992-02-13 | Metz Mannheim Gmbh, 6800 Mannheim, De | |
JP2522730B2 (ja) * | 1991-05-02 | 1996-08-07 | 黒木 重光 | 液流発生を兼ねた曝気装置 |
US5205237A (en) * | 1991-10-18 | 1993-04-27 | Skeggs Leonard T | Method and apparatus for growing fish in a recirculating tank |
IT1254714B (it) * | 1992-01-20 | 1995-10-09 | Filtro percolatore a pressione del tipo impiegato per la rigenerazione dell'acqua di acquari. | |
JP2704691B2 (ja) * | 1992-05-01 | 1998-01-26 | 株式会社 ナイガイコーポレーション | 養殖装置 |
JP2838130B2 (ja) * | 1992-06-01 | 1998-12-16 | ジンヴェント アクチエセルスカベット | 粒子トラップ |
US5450818A (en) * | 1993-09-29 | 1995-09-19 | Float Culture Systems, Inc. | Floating fish cultivating system and related method |
JP2618326B2 (ja) * | 1993-12-28 | 1997-06-11 | 有限会社オーディーアイ | 海水魚の飼育方法及びそのための観賞用水槽 |
JPH10337131A (ja) * | 1997-06-09 | 1998-12-22 | Yamaha Motor Co Ltd | 魚用養殖装置 |
US6065430A (en) * | 1997-10-10 | 2000-05-23 | Sheriff; Richard L. | Fish culturing system |
JP3208125B2 (ja) * | 1999-02-15 | 2001-09-10 | 株式会社広瀬 | 濾過装置付き水盤 |
-
2003
- 2003-02-13 AU AU2003206116A patent/AU2003206116B2/en not_active Ceased
- 2003-02-13 EP EP03703000A patent/EP1473986A4/de not_active Withdrawn
- 2003-02-13 KR KR10-2004-7012491A patent/KR20040096565A/ko not_active Application Discontinuation
- 2003-02-13 JP JP2003567167A patent/JP2005538688A/ja active Pending
- 2003-02-13 WO PCT/IL2003/000112 patent/WO2003067966A2/en active Application Filing
Patent Citations (3)
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GB1592085A (en) * | 1977-08-26 | 1981-07-01 | Fisons Ltd | Fish rearing apparatus |
WO1990003109A1 (en) * | 1988-09-22 | 1990-04-05 | Sinvent As | Device for tanks for the rearing of aquatic organisms |
DE19521037A1 (de) * | 1995-06-09 | 1996-12-12 | H J Dipl Ing Schultze | Becken zur Fischzucht |
Non-Patent Citations (1)
Title |
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See also references of WO03067966A2 * |
Also Published As
Publication number | Publication date |
---|---|
JP2005538688A (ja) | 2005-12-22 |
AU2003206116B2 (en) | 2009-07-02 |
WO2003067966A3 (en) | 2004-04-08 |
AU2003206116A1 (en) | 2003-09-04 |
KR20040096565A (ko) | 2004-11-16 |
EP1473986A4 (de) | 2008-03-12 |
WO2003067966A2 (en) | 2003-08-21 |
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