This subject invention relates to methods and systems for treating fish (e.g., salmon) to rid them of parasites. (e.g., sea lice).
Fish farming is a large business but the damage caused by parasites cost fish farmers huge sums of money each year. Chemical treatments (see, e.g., U.S. 2013/0095126, incorporated herein by reference) may be ineffective and/or costly, may damage or kill the fish, and/or may pollute the water and/or damage other organisms. Certain pesticides, drugs, vaccines, and the like may result in genetically resistant sea lice.
Warm water and/or fresh water treatments may be ineffective, expensive, and often require long treatment times. Moreover, if the sea lice become resistant to fresh water, then wild saltwater fish migrating in fresh water can be put at risk.
Some mechanical treatments have been proposed. For example, WO 98/24314, incorporated by reference herein, proposes using water jets to remove sea lice from salmon. But, the water jets are fixed in place. Since the salmon are not stationary, and are not a constant size, large fish may be damaged by the water jets and, for smaller fish, the jet pressure may not be great enough to effectively remove the sea lice. Moreover, the water from the spray nozzles has to travel through water before reaching the surface of the fish body lowering the effectiveness of the water jet. And, the water jets are in a single fixed configuration with fixed angles.
In one preferred method and system, fish (e.g., salmon) are treated in two zones in a cost effective and expedient manner to more effectively remove parasites (e.g., sea lice) from the fish. The throughput of the preferred system results in many fish being treated in a short amount of time. Parts of the process may include a batch treatment or the system may be configured for a continuous process. In the first treatment zone (which may be optional), the fish are subject to a treatment that kills and/or weakens the parasites. This may include chemical treatments, for example, some sort of osmotic de-regulation that may be used in the first zone for killing, paralyzing, and/or weakening the parasites. Optionally, or in addition, the pH level of the sea water in the first treatment zone may be adjusted up or down, or both, to speed and increase the effectiveness of the treatment. Other substances such as hydrogen peroxide may be used. Other treatments may include varying temperature, salinity, dissolved gases, light exposure, or any other methods including sound, pressure, ultrasound, electrostatic, electromagnetic, laser, and/or plasma exposure that may kill or weaken the parasites. The parasites may be killed or weakened by the treatment(s) in the first treatment zone. Some parasites may be weakened or temporarily paralyzed but still attached to the fish. Other parasites may be released from the fish in the first treatment zone.
In the second treatment zone, physical treatments, (e.g., fish agitation, water jets sprayed through air at the fish) remove parasites from the fish. The removed parasites and their eggs (if any) may be collected by the system, killed (if still alive) and may be used as food (e.g., food for the fish that were previously treated), or for other purposes. The dead parasites may also be collected and simply discharged back into the ocean. This also applies to the parasite's egg-strings and loose eggs. Preferably, the fish are not stressed or harmed, the environment is not harmed, and the method and system are cost effective. 90-100% of the parasites may be removed from the fish using the systems described herein.
Featured is a system for removing parasites from fish comprising a conduit through which individual fish pass, a plurality of arms associated with the conduit circumferentially spaced with respect to each other, a treatment head unit for each arm for dislodging parasites from the fish, and means for adjusting the arms for closely spacing the head unit with respect to the fish.
In some versions, the head unit includes at least one nozzle connected to a fluid source. The fluid source may be temperature controlled. In some designs, the nozzle is connected to a particulate source. Also, the head unit may includes a vacuum head.
Preferably, the nozzle is set at a predetermined angle with respect to the surface of the fish and the system further includes means for maintaining said predetermined angle. In one design, the head unit includes a shoe pivotably attached to the arm and the nozzle is affixed to the shoe. The arm may include a ball pivotably received in a socket attached to the shoe. The shoe may include spaced fingers and the nozzle is positioned between the spaced fingers. The system may further include means for adjusting the nozzle. In one design, the means for adjusting oscillates the nozzle and/or changes the angle of the nozzle about one or more axes.
The system may further include a sensor subsystem configured to recognize features on the fish. The nozzle can be adjusted depending on a sensed fish feature.
The nozzle may be a ball nozzle received in a socket in the head unit and the means for adjusting includes one or more drivers associated with the head unit socket engaging the ball nozzle. In some designs, the arm constitutes a bar linkage pivotably attached to, or in proximity to, the conduit. A spring associated with a bar linkage biases it away from the conduit.
In some versions, the conduit includes a flexible chute circumferentially expandable to accommodate different sized fish. The arms may extend from a ring disposed about the chute and extend and retract based on the size of the fish in the chute.
The system may further include a treatment zone upstream of the conduit where fish are pretreated to kill parasites, paralyze the parasites, weaken the parasites, and/or weaken the attachments of any parasites on the fish.
Also featured is a method of treating fish. Fish travel from a pen to a first treatment zone where the fish are pretreated to kill any parasites on the fish, to weaken any parasites on the fish, and/or to weaken the grip of any parasites on the fish. The fish are singulated and/or oriented for travel through an inclined or vertical conduit of a second treatment zone. At the second treatment zone, at least one treatment head is maintained at a near constant effective distance with respect to the fish body surface to dislodge parasites from said fish. After treatment the fish are discharged.
The fish in the first treatment zone may proceed therethrough in a batch or continuous process. Maintaining the treatment head position may include using one or more pivoting arms with a treatment head mounted thereto. Maintaining the treatment head may include using one or more extendible and retractable arms with a treatment head mounted thereto. The conduit may include a flexible chute.
The fish may move continuously through the first treatment zone while being pretreated. The treatment head may produce a fluid spray directed at the fish. The fluid spray may be temperature controlled. The fluid spray may is preferably maintained at a predetermined angle relative to the surface of the fish. The fluid spray may oscillate. The fluid spray may adjust between different spray angles relative to the surface of the fish. The fluid spray angle may adjust depending on a fish feature being treated. The method may further include killing said dislodged parasites.
The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving all of these objectives.
Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:
Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.
Fish in pen 10 are transported in sea water to the first treatment zone 12. Various mechanisms can be used to transport fish in sea water, which may include: vacuum pumps, conveyors, or Archimedes' screws. See WO 2014/129908 and also WO 2014/184776 both incorporated by reference herein.
In first treatment zone 12, the fish may be treated with a substance (e.g., a solution) introduced into the treatment zone 12 as shown at 16. An exemplary dwell time may be 2-30 (e.g., 5) minutes. Preferred is an osmotic deregulator which weakens, paralyzes, and/or kills sea lice on the fish. Examples include Brine (CaC03), iodine, potassium iodide, and lactic acid (e.g. four parts per thousand). Other possible treatments include known chemicals and compounds. Adjusting other variables, such as dissolved gases, salinity, and temperature, in conjunction with an osmotic deregulator or other treatment substance may decrease treatment time and improve effectiveness. The pH level of the water in treatment zone 12 may be adjusted to decrease treatment time and improve effectiveness. See, U.S. Pat. No. 8,759,073 incorporated by reference herein. For example, sodium hydroxide may be used to raise the pH of the sea water while maintaining a safe level of pH and exposure time for the fish to approximately 10.0. Hydrochloric acid may be used to lower the pH of the sea water to approximately 4.0 while maintaining a safe level of pH and exposure time for the fish. Again, the dwell time, in one example, may be between two and thirty (e.g., five) minutes. If needed, the water output from treatment zone 12 may be treated again to bring it back to a nominal pH level (e.g., 8.3). Ozone may also be used in treatment zone 12. See, for example, WO 2014/129908 and WO 2013/066191 (both incorporated herein by this reference). The water temperature in the first treatment zone may be controlled to improve the effectiveness of the treatment and to improve the general health of the fish during treatment
In treatment zone 12, some or all of the parasites will be killed or at least weakened. One or more of the above described treatments as well as others may be used in treatment zone 12. The parasites may be weakened to the point they are not as strongly attached to the fish. Some parasites may be removed from the fish.
The fish are then preferably transferred to second treatment zone 18 where a physical treatment is preferred to remove parasites from the fish. Treated fish with reduced parasites are then returned to a pen. The fish may optionally be sedated for the treatment in the first and/or second zone.
The system may further include separation zones 22a, 22b, and 22c where lice (and/or their eggs) in the sea water and/or another solution present in the system are collected and exterminated at station 24. UV radiation may be used. Other extermination means may be used. The dead sea lice may be transported to storage vessel 26 for use as fish food, for example. The separation zones may include, for example, grates, filters, and the like through which water and any sea lice (and/or their eggs) pass but fish are directed to a different path. These separation zones ensure the parasites do not reattach themselves to the fish and ensure that any eggs do not mature into parasites. There may be a singulation and/or orientation mechanism 28 upstream of treatment zone 18 so only a single fish at a time, oriented head first, enters treatment zone 18. Singulation and/or orientation may also be performed manually with a mechanism to present the fish to human operators for this purpose. Sea water may be sprayed on the fish in treatment zone 18 via pump 14b. Pump 14c may be used to pump sea water at separation zone 22b to mix with the treatment solution at 16 which is pumped into treatment zone 12. Any removed sea lice and egg strings in the system due to spraying of the fish, scraping of the fish, and/or due to movement of the fish, or treatment of any kind of the fish, may be removed from the system in separation zone 22c where water and removed sea lice are directed to extermination zone 24. In some examples, the fish are not swimming in the sea water in second treatment zone 18.
A treatment solution or compound such as shown at 16 is then pumped into chamber 32a to treat the fish for a predetermined dwell time after which gate 30b is opened and, the fish may be singulated and oriented at station 28 to travel within one or more conduits, 42a, 42b, 42c of treatment zone 18. The fish, after mechanical treatment in treatment zone 18 then pass through separation zone 22c and back into a pen.
A continuous flow system is shown in
Also, whenever the fish must be transported from one location to another in the overall system, the subsystems shown in
Optionally, a treatment substance as shown at 16 is introduced into the sea water in vertical conveyor 70 to treat the fish and kill or at least weaken the sea lice or other parasites as the fish move upwards in the conveyor. The pH of the sea water may be raised or lowered, a chemical or biological agent may be used, the water may be warmed or cooled, and/or an osmotic treatment may be used. Other treatments may be used as well. Thus, in this example, the device which moves the fish into the system is also the first treatment zone.
Then, the fish, now in air, travel in downwardly inclined conduit 42 and are subject to mechanical treatment in treatment zone 18. Preferably, the treatment zone 18 constitutes a continuous treatment subsystem. In one preferred embodiment, a series of circumferentially oriented treatment heads (e.g., spray heads) 80 are used. For example, there may three sets of spray heads with four or eight spray heads in each set. If four spray heads are used, they may be oriented 90° apart and if eight spray heads are used they may be oriented 45° apart. The spray heads function to dislodge the parasites from the fish. In separation zone 22b, there is a grate or filter as shown at 73 for removing from conduit 42 any fluid ejected by the spray heads. Again, any sea lice (and/or eggs) in this fluid may be filtered out, collected, and/or destroyed. The conduit may be inclined to provide the optimal velocity and efficacy e.g., between 5 and 90° with respect to horizontal. Killing the eggs in the system can prevent lice from these eggs from returning which could create further problems.
Featured in some embodiments are treatment heads which are urged close to the fish 67 no matter their size. Also, the spray heads may be configured to always spray a fluid, (e.g., water or gas) at a constant angle relative to the fish outer surface. A treatment substance may also be added to the fluid supplied to the spray heads.
In systems with fixed spray heads, small fish may not receive enough of a pressurized spray to dislodge sea lice and a large fish may receive a pressurized spray at too high a pressure and/or velocity, and/or momentum which damages the fish scales, eyes, fins, or the like. This problem is addressed in the subject invention.
Also, any given fish body is small in diameter at the head, then larger in the middle, and them smaller again at the tail. Fixed in place spray heads do not account for this change in fish geometry. This problem too is addressed in the subject invention is discussed below. Finally, prior systems sprayed fluid towards the fish while the fish were in water. The water generally diminishes the effectiveness of the fluid jet spray by diminishing the jet velocity and/or impact pressure, and/or momentum. This problem too is addressed in the subject invention since the fish preferably travel in conduit 42 in air or other medium. In prior systems, if the fish in water passed too close to a given fixed jet spray head then the fish could be harmed including any damage to the eyes or other sensitive areas.
In
Shoe 96 may be made of or include a slippery top surface (e.g., Delrin or Teflon or similar type material) so as not to harm the fish. The shoe may also function to scrape parasites off the fish body. As shown in
In this way, the jet spray is more effective: the cleaning spray is in air, the spray nozzle is kept a near constant distance from the fish no matter its size or what portion of orientation anywhere along the circumference of the conduit the fish is being treated, and the jet spray remains at a near constant angle relative to the fish body. With the cleaning sprays in air, little energy is lost from the spray as it moves through air to the lice and fish surface. Alternatively, if the fish and spray jets are in water, as long as the spray nozzle is kept a near constant distance from the fish and a near constant angle relative to the fish body, the spray pressure may be adjusted to remain effective.
In
By using a four bar or other linkage, the spray head nozzle is kept at a constant distance from the fish body and at a constant angle relative to the longitudinal axis of the conduit. The linkage keeps the spray head at a constant angle with respect to the pipe wall as the linkage and the spray head follows the outer surface of the fish moving by. With pivoting shoes on the outer bar, the head will follow the fish surface and keep the jet spray angle constant with respect to the fish surface while bar 102 stays parallel to the pipe wall. Compression spring 116 between arms 108 and 110 may be used to bias the four bar linkage away from the conduit (e.g., at a 90° angle relative to the longitudinal axis of the conduit wall).
In some examples, opposing spray heads may be 1-2 inches apart from each other (when the arm is 90° to the conduit), the spray heads may be disposed a near constant distance of 1-2 inches from the fish body, may provide a fluid spray at a pressure, for example, of 25-200 PSI and at a flow rate, for example, of 0.5-1 GPM to effectively remove parasites. Closer distances of the nozzle to the fish may be possible (e.g., 1-2 mm). Fan shaped sprays or other shapes may be used to optimize treatment coverage on the surface of the fish regardless of the shape and size of the fish. Different sets of nozzles may be in stages of the process to give maximum efficiency. The fan nozzles may overlap as needed for the biggest fish (bigger circle) and thus the longest circumference and distance between the nozzles. In one example, the final cleaning of the fish to remove salmon lice and eggs may be done by “curtain” nozzles. Flat shaped jets or jets that are made out of a slit in the circumference of the tube that face inwardly may be used, to make the pressure variation less dependent on the distance from the head of the jet.
There are other means for adjusting the arms depending on the size of the fish and the conduit and for closely spacing the spray head nozzles with respect to the fish. For example,
The material of the chute may assist in scraping sea lice or other organisms off the surface of the fish in the second treatment zone 18. The material of the chute, however, should be configured to allow the water jet to reach the surface of the fish body. In this example, there is a ring 120 disposed about the chute and the spray heads 80 (in this example 8 spray heads) are mounted on piston arms 122 extending inwardly from the ring 120. Ring 120 may form a distributor for the fluid delivered to it via hose 92 and thus is configured to deliver the fluid to the individual spray heads via their respective arms. This radially expandable chute may also act as a speed controller, so the fish is constantly treated equally over its length passing the nozzles at a controlled speed.
The piston arms may extend and retract based on the size of fish 27 in the chute and the area being treated (e.g., head, body, tail) to keep the spray nozzles of the spray head at a constant or near constant close distance to the surface of fish 27. Preferably, the spray nozzles of the spray heads are oriented to spray rearwardly along the body of fish 27 to effectively remove parasites and to prevent damage to the scales of fish 27. The piston arms may be actuated. The spray heads may also rotate as shown by arrow 81 (e.g., up and down) to vary the spray angle. Conforming fan sprays may be used.
One or more sensors 130 may be used to sense the distance of the body of fish 27 from the ring 120 (or, alternatively, a nozzle). The output of the sensor(s) may be fed to a processor (not shown) which then drives the actuators of the piston arms accordingly to keep the spray heads at a desired distance to the fish body. The sensor subsystem could be based on capacitance, for example, with the exterior of chute 42′ including markers which can be sensed by the sensor(s). Other sensor subsystems may be used. In other examples, the nozzles are attached to the material of the chute or sleeve. See
The ring/piston arrangement shown in
The result in any embodiment is a more effective treatment method and system which is cost-effective and which is ecologically sound.
Preferred are means for maintaining a head unit close to, at a constant or near constant distance from, the surface of the fish irrespective of the size of the fish, the portion of the fish being treated, the position of the fish in the conduit, and the like. In
One or more nozzles may be configured for droplet impingement. One or more nozzles may be configured for particle impingement (e.g., CO2, ice particles, or the like).
In some designs, the angle of the nozzle relative to the surface of the fish is fixed and yet remains at a constant or nearly constant angle with respect to the surface of the fish.
As shown in
For example, nozzles may be desired which quickly oscillate between a tangential spray as shown at 226,
In still other designs, the angle of the spray may be adjusted depending on the portion of the fish being treated. For the main body of the fish, a tangential or near tangential spray may be desired. At the head of the fish, a shallow angle, rearwardly directed spray may be desired to protect the eyes and gills of the fish. When the pelvic fin or anal fin are detected, for example, it may be desirable to oscillate or adjust the nozzle along one or both axes 222,
The nozzles may oscillate continuously about one or more axes. Alternatively, or in addition, the nozzle spray angle may be adjusted based on the portion of the fish being treated. A sensor 250 is shown in
Besides nozzles spraying fluid (e.g., treatments and/or temperature controlled fluids or particles),
Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. Other embodiments will occur to those skilled in the art and are within the following claims.
In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant cannot be expected to describe certain insubstantial substitutes for any claim element amended.
This application claims benefit of and priority to U.S. Provisional Application Ser. No. 62/486,598 filed Apr. 18, 2017, under 35 U.S.C. §§ 119, 120, 363, 365, and 37 C.F.R. § 1.55 and § 1.78, which is incorporated herein by this reference.
Number | Date | Country | |
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62486598 | Apr 2017 | US |