Aquaculture system

Abstract

An aquaculture system ( 10 ) comprising a building structure ( 11 ) defining a scaled environment ( 13 ) having an access system ( 17 ) incorporating an airlock ( 18 ), a culture tank ( 35 ) and water treatment means ( 41 ) for treating water in the culture tank for removing contaminants to maintain water quality. The system also, has air supply means ( 27 ) and temperature control means ( 31 ). A mechanical filtration system using an endless belt and biological filtration apparatus are also disclosed.

1 . An aquaculture system comprising a cell defining a closed environment, the cell having an access system incorporating an airlock for access to and from the closed environment, at least one culture tank accommodated in the closed environment, and water treatment means for treating water in the or each culture tank for removing contaminants therein to maintain the water of a quality appropriate to the species under culture.  
     
     
         2 . An aquaculture system according to  claim 1  further comprising a water supply means for introducing water of a quality appropriate to the species under cultivation into the environment.  
     
     
         3 . An aquaculture system according to  claim 1  or  2  further comprising air supply means for introducing air of a quality appropriate to the species under culture into the closed environment.  
     
     
         4 . An aquaculture system according to  claim 1 ,  2  or  3  further comprising power supply means for introducing electrical power to the closed environment.  
     
     
         5 . An aquaculture system according to any one of  claims 1  to  4  wherein the water treatment means comprises a plurality of filtration devices in a serial arrangement, water being extracted from the or each culture tank and contacted by the filtration devices for filtering thereof prior to being returned to the culture tank or tanks.  
     
     
         6 . An aquaculture system according to  claim 5  wherein the filtration devices provide mechanical filtration and biological filtration.  
     
     
         7 . An aquaculture system according to  claim 5  or  6  wherein the filtration devices include a mechanical filtration apparatus comprising a moveable structure incorporating a filter screen, means for contacting a portion of the filter screen with the water, and means for periodically moving the filter screen for varying the portion thereof being contacted by the water.  
     
     
         8 . An aquaculture system according to  claim 7  wherein the filter screen comprises a plurality of screen sections disposed along a direction of movement of the moveable structure.  
     
     
         9 . An aquaculture system according to  claim 7  or  8  wherein the moveable structure comprises an endless belt.  
     
     
         10 . An aquaculture system according to  claim 7 ,  8  or  9  wherein the means for contacting a portion of the moveable structure with the water comprises a receiving chamber into which the water can be delivered and from which the water can flow under gravity through the filter screen.  
     
     
         11 . An aquaculture system according to any one of  claims 7  to  10  wherein the mechanical filtration apparatus further comprises a cleaning means for cleaning a respective portion of the filter screen after that portion has moved out of contact with the liquid.  
     
     
         12 . An aquaculture system according to  claim 11  wherein the cleaning means comprises a washing system for applying a washing liquid to the respective portion of the filter screen.  
     
     
         13 . An aquaculture system according to  claim 12  wherein the cleaning liquid comprises water applied as a spray.  
     
     
         14 . An aquaculture system according to any one of  claims 5  to  12  wherein the filtration devices include a biological filtration apparatus comprising a contact chamber, aeration means for introducing air into water contained in the chamber, and a protein skimmer for collecting foam bubbles generated by aeration of the water, the protein skimmer comprising a body defining a tray for receiving foam bubbles.  
     
     
         15 . An aquaculture system according to  claim 14  wherein the tray surrounds a collar disposed about an opening extending through the body, the opening accommodating a delivery pipe of the aeration means with a clearance space therebetween.  
     
     
         16 . An aquaculture system according to  claim 14  or  15  wherein the biological filtration apparatus further comprises a further contact chamber, a further aerating means for introducing air into a body of liquid contained in the further contact chamber, and a further protein skimmer wherein the two contact chambers are connected in series in a liquid flow circuit such that water undergoing biological filtration passes upwardly through one contact chamber and downwardly through the other contact chamber.  
     
     
         17 . An aquaculture system according to  claim 16  wherein the liquid flow circuit has an inlet in one contact chamber and an outlet in the other contact chamber, the inlet and outlet each opening onto the respective contact chamber in a lower region thereof.  
     
     
         18 . An aquaculture system according to any one of  claims 6  to  17 , wherein the biological filtration is performed by a first biological filter and a second biological filter.  
     
     
         19 . An aquaculture system according to  claim 18  wherein the first biological filter is disposed beneath the mechanical filtration apparatus to receive water directly therefrom.  
     
     
         20 . An aquaculture system according to  claim 18  or  19  wherein the second biological filter comprises said biological filtration apparatus.  
     
     
         21 . An aquaculture system according to any one of the preceding claims wherein the water treatment means comprises a sterilisation system for sterilising the water as appropriate.  
     
     
         22 . A mechanical filtration apparatus comprising a moveable structure incorporating a filter screen, means for contacting a portion of the filter screen with a liquid requiring filtering, and means for periodically moving the filter screen for varying the portion thereof being contacted by the liquid.  
     
     
         23 . A mechanical filtration apparatus according to  claim 22  wherein the filter screen comprises a plurality of screen sections disposed along a direction of movement of the moveable structure.  
     
     
         24 . A mechanical filtration apparatus according to  claim 22  or  23  wherein the moveable structure comprises an endless belt.  
     
     
         25 . A mechanical filtration apparatus according to  claim 22 ,  23  or  24  wherein the means for contacting a portion of the moveable structure with the liquid comprises a receiving chamber into which the liquid can be delivered and from which the liquid can flow under gravity through the filter screen.  
     
     
         26 . A mechanical filtration according to any one of  claims 22  to  25  further comprising a cleaning means for cleaning a respective portion of the filter screen after that portion has moved out of contact with the liquid.  
     
     
         27 . A mechanical filtration according to  claim 26  wherein the cleaning means comprises a washing system for applying a washing liquid such as water to the respective portion of the filter screen.  
     
     
         28 . A biological filtration apparatus incorporating a protein skimmer, characterised in that the protein skimmer is disposed above a body of liquid undergoing biological filtration.  
     
     
         29 . A biological filtration apparatus comprising a contact chamber, aeration means for introducing air into a body of liquid contained in the chamber, and a protein skimmer disposed above the body of liquid for collecting foam bubbles generated by aeration of the liquid.  
     
     
         30 . A biological filtration apparatus according to  claim 29  wherein the protein skimmer comprises a body defining a tray for receiving foam bubbles.  
     
     
         31 . A biological filtration apparatus according to  claim 30  wherein the tray surrounds a collar disposed about an opening extending through the body, the opening accommodating a delivery pipe of the aeration means with a clearance space therebetween.  
     
     
         32 . A biological filtration apparatus according to  claim 29 ,  30  or  31  comprising a further contact chamber, a further aerating means for introducing air into a body of liquid contained in the further contact chamber, and a further protein skimmer disposed above the body of liquid, wherein the two contact chambers are connected in series in a liquid flow circuit such that liquid undergoing biological filtration passes upwardly through one contact chamber and downwardly through the other contact chamber.  
     
     
         33 . A biological filtration apparatus according to  claim 32  wherein the liquid flow circuit has an inlet in one contact chamber and an outlet in the other contact chamber, the inlet and outlet each opening onto the respective contact chamber in a lower region thereof.  
     
     
         34 . A water treatment system comprising a water circuit including a biological filter, a pump disposed on the downstream side of the biological filter, and an air-injected UV steriliser disposed on the downstream side of the pump.  
     
     
         35 . An aquaculture system substantially as herein described with reference to the accompanying drawings.  
     
     
         36 . A mechanical filtration apparatus substantially as herein described with reference to the accompanying drawings.  
     
     
         37 . A biological filtration apparatus substantially as herein described with reference to the accompanying drawings.