WO2008026933A1

WO2008026933A1 - A method of cleaning a seine and an apparatus for use when practising the method

Info

Publication number: WO2008026933A1
Application number: PCT/NO2007/000300
Authority: WO
Inventors: Walter Johannes Bennett
Original assignee: G2 Ultrasonic As
Priority date: 2006-08-28
Filing date: 2007-08-27
Publication date: 2008-03-06
Also published as: NO20063834L; CL2007002452A1; NO325433B1

Abstract

The invention comprises a method of treating seine material (11), in particular seine material (11) connected with a net cage for fish farming, the method including the steps of: letting the seine material (11) pass an ultrasonic field (7a) so as to free the seine material (11) of undesired materials; and collecting the released, undesired materials which have been released from the seine material (11). The invention also comprises an apparatus (1) for use when implementing the method.

Description

A METHOD OF CLEANING A SEINE AND AN APPARATUS FOR USE WHEN PRACTISING THE METHOD

The invention relates to a method of cleaning a seine, more particularly a method, in which the seine, or at least parts of it, is/are treated with ultrasound. The method also includes collecting waste materials, which are released from the seine, and applying seine-preserving substances. The invention also includes an apparatus for use when practising the method.

In the fish-farming trade it is known to clean the seine walls in the farming net cage by, for example, flushing with water under high pressure. This is carried out substantially by the seine being pulled out of the water masses, possibly to undergo a drying process before being placed, for example, on a relatively plane surface where the cleaning is done by flushing. There are also washing drums, into which the seine material is placed, and in which washing of the seine material is carried out by rotation and flushing with water.

The cleaning process is laborious and causes great wear to the seine material and other enclosure components. The process also causes pollution of the surroundings, as the waste materials, for example biological material which is released from the seine, remnants of old impregnating agent with which the seine material has been treated in the production or in earlier cleaning, are difficult to collect because of, among other things, the large amounts of water used, and are thereby, to a great degree, carried into the adjacent water masses .

The invention has for its object to remedy or reduce at least one of the drawbacks of the prior art.

The object is achieved through the features, which are specified in the description below and in the claims that follow.

A primary object of the invention is to provide an apparatus and a method which simplify the cleaning of a seine material and take care of environmental issues concerning the control of emissions of biological material, toxic substances etc. into nature.

The invention relates to a method, in which the seine material which is to be cleaned, is passed through an ultrasonic field, the ultrasonic waves providing for undesired material, for example biological material growing on the seine wall, and old impregnating agent with which the seine wall has been treated in an earlier production or cleaning process, to be released from the seine. Preferably, the method includes a step in which the seine material is pulled out of the water masses in which, for example, a farming net cage is standing, and is passed through one or more vessels, in which the ultrasonic treatment is carried out continuously while the seine material is being pulled past an elongated ultrasound source. The waste material, which is released from the seine, is collected in vessels and can be passed on for destruction or other treatment without the risk of return to the water masses. A new impregnating agent can also be applied to the seine material in connection with the cleaning process. The invention also relates to an apparatus for use when practising the method. The apparatus includes an ultrasound source which is preferably located in an elongated vessel filled with liquid, which is arranged to collect the material released from the seine material which is moved by means of actuators and guide elements, for example drive rollers and guide rollers, past the ultrasound source, in the immediate vicinity thereof.

In connection with said apparatus is preferably disposed a device for applying a new impregnating agent to the cleaned seine material. This can be carried out by means of, for example, immersion in a container filled with impregnating liquid or by spraying with the same type of liquid. The apparatus advantageously includes devices for collecting and recirculating excess impregnating agent.

In a first aspect the invention relates more specifically to a method of treating a seine material, in particular a seine material in connection with a net cage for fish farming, characterized by the method comprising the steps of: letting the seine material pass an ultrasonic field so as to free the seine material of undesired materials; and collecting the released, undesired materials which have been released from the seine material.

The ultrasonic field is preferably provided by means of an ultrasound source extending substantially across the entire width of a conveyance track for the seine material under treatment .

The ultrasonic field is preferably provided in a container filled with a cleaning liquid.

The collecting of the released, undesired materials is advantageously carried out by circulation of the cleaning liquid in the container through a connected circulation circuit which is provided with a separating system which is arranged to separate the released, undesired materials from the cleaning liquid.

The cleaning liquid is preferably water-based.

Advantageously, the method further includes the step of supplying an impregnating agent to the seine material.

The impregnating agent is supplied to the seine material after it has passed through the ultrasonic field.

The impregnating agent is preferably supplied to the seine material by immersion of the seine material into an impregnation pool. Alternatively, the impregnating agent is sprayed over the seine material .

Advantageously, the method includes the further steps of: before the seine material is submerged into the cleaning liquid, lifting the seine material out of a body of water, in which it has been in an operative position; and after treatment of the seine material, returning the seine material into an operative position in the body of water.

Subsequent to at least cleaning, the seine material is advantageously stored temporarily in a storage, in which it undergoes an after-treatment comprising drying.

The sound frequency, which is used, preferably lies in the range of 10 kHz - 50 kHz, more preferably in the range of 20 kHz - 35 kHz.

In a second aspect the invention includes an apparatus for cleaning seine material, in particular seine material connected with a net cage for fish farming, characterized by comprising : an ultrasound source, a container which is arranged to hold a liquid, a conveyance track for the seine material arranged to move the seine material through the container, and means for moving the seine material along the conveyance track; the ultrasound source being arranged to be placed in a submerged manner in the container, and the conveyance track including at least one portion which is submerged, in an operative position, in a cleaning liquid and is arranged to move the seine material past the ultrasound source at a defined distance and parallel thereto.

Preferably, the ultrasound source is arranged to provide a sound frequency in the range of 10 kHz - 50 kHz, more preferably in the range of 20 kHz - 35 kHz.

Preferably, the container is connected in a liquid- communicating manner to a circulation circuit including a separating system, which is arranged to separate undesired materials and substances from said cleaning liquid.

Said cleaning liquid is preferably water-based.

The means for conveying the seine material advantageously includes one or more wind-up rollers.

Advantageously, the apparatus is provided with a device for supplying a liquid impregnating agent to the seine material.

The device for supplying an impregnating agent is preferably constituted by a container, which is arranged to hold the impregnating agent, and the conveyance track for the seine material includes at least one portion, which is submerged in the impregnating agent in an operative position. Alternatively, the means for supplying the impregnating agent is formed by a dosing system including one or more nozzles, which are arranged to distribute the impregnating agent across the entire width of the conveyance track.

To the device for supplying an impregnating agent to the seine material is/are advantageously connected one or more devices for collecting and recirculating excess impregnating agent, which has been released from the treated seine material .

In what follows is described a non-limiting example of a preferred embodiment which is visualized in the accompanying drawings, in which:

Figure 1 shows schematically an apparatus according to the invention during cleaning of the seine material, the seine material being pulled through an ultrasonic field formed, in the main, in a liquid pool;

Figure 2 illustrates schematically that the liquid in the pool is circulated during the cleaning of the seine material ;

Figure 3 shows schematically that the container of the apparatus is being filled with an impregnating liquid;

Figure 4 shows schematically that impregnating liquid sprinkles / is sprayed onto the seine material as it is pulled out of the apparatus according to the invention and excess liquid runs down into the container; Figure 5 shows a schematic, perspective sketch of an apparatus according to the invention; and

Figure 6 shows a situation in which the seine material has been pulled through the apparatus.

In the drawings an apparatus according to the invention is indicated by the reference numeral 1. The apparatus 1 is provided with a pull-in roller 3, which is arranged with motor drive (not shown) , a wind-up roller 4 which is arranged with motor drive (not shown) and synchronized with the motor drive of the pull-in roller 3, and an elongated container 5 provided with an open top 5a. In the container 5 four elongated guide rollers 6 form a loop in a conveyance track for a seine material 11 between the pull-in roller 3 and the wind-up roller 4. Centrally within the container 5 and placed approximately in the middle of said loop is disposed an elongated ultrasound transmitter 7.

The container 5 is provided with an inlet pipe 51 for liquid. The inlet pipe 51 extends substantially in the entire length of the container 5 and is provided with several outlet openings for liquid. Via several outlets 53, a bottom portion of the container 5 is in fluid communication with an outlet pipe 54. The inlet and outlet pipes 51, 54 are in fluid communication with a cleaning plant 55, said container 5 together with pumps and valves (not shown) and said inlet and outlet pipes 51, 54, forming a circulation circuit for a water-based cleaning liquid 13, for example sea water, surrounding the ultrasound transmitter 7 when the apparatus 1 is being used, and forming a medium for conveying ultrasonic waves and conveying away contaminants from the seine material 11.

The cleaning plant 55 includes in a manner known per se means for mechanical and possibly chemical separation of contaminants from the cleaning liquid 13, and collecting and further controlled processing of biological material and residual amounts of chemical compounds. These means will not be described in any further detail here as a great number of systems can be used for the purpose.

The inlet and outlet pipes 51, 54 are also in fluid communication with a tank 56 for an impregnating liquid 14, pumps and valves (not shown) together with the tank 56, container 5 and said inlet and outlet pipes 51, 54, forming a circulation circuit for the impregnating liquid 14.

In an alternative exemplary embodiment, in which an impregnating liquid 14 is applied to the cleaned seine material 11 by sprinkling/spraying, the outlet openings of the inlet pip 51 can be directed in such a way that the exiting impregnating liquid 14 is directed towards a portion of the conveyance track of the seine material 11 in order, thereby, to apply impregnating liquid 14 to the seine material 11 in the entire width of the seine material 11 and in such a way that excess impregnating liquid 14 can flow into the container 5 and be recirculated into the tank 56. This is illustrated schematically in figure 4.

The apparatus 1 according to the invention is located in a place suitable for that purpose. For example, it may be placed temporarily or permanently at the edge of a farming net cage. The seine material 11 to be treated is connected to the wind-up roller 4, for example by ropes, which are secured to a portion of the seine wall of the net cage, being passed over the pull-in roller 3 and along the conveyance track through the apparatus 1 to the wind-up roller 4 and secured there. The container 5 is filled with cleaning fluid 13, for example seawater, preferably in such a way that the ultrasound source 7 is immersed. The ultrasound source 7 is activated so that it emits sound waves, propagating in particular in the masses of water within the container 5. The most favourable sound frequency depends on the design of the apparatus, especially the size, shape and position of the container, and generally lies in the range of 10 kHz - 50 kHz, more specifically in the range of 20 kHz - 35 kHz.

The apparatus includes a framework 2.

The seine material 11 is pulled at a prescribed speed through the apparatus 1 by putting the pull-in roller 3 and wind-up roller 4 into operation. The seine material 11, immersed in the cleaning liquid 13, passes the ultrasound source 7. The sound waves make undesired materials, for example but not limited to, biological material growing on the seine wall of the enclosure, and remnants of impregnating liquid, come loose from the seine material 11 and be carried away from the container 5 with the cleaning liquid 13 which is circulated through the cleaning plant 55, in which the undesired materials are separated to undergo further processing, for example dehydration of biological material for land disposal and recovery of impregnating substance. The seine material 11 is wound onto the wind-up roller 4.

When a prescribed amount of seine material 11 has been cleaned, the rotation of the pull-in roller 3 and wind-up roller 4 is stopped. The container 5 is emptied of cleaning liquid 13.

By reversal of the driving gear of the pull-in roller 3 and wind-up roller 4 the seine material is moved out of the apparatus 1 and back into an operative position in the enclosure. During this process the seine material can be impregnated. In a first embodiment of the invention the container 5 is filled to a prescribed level with an impregnating liquid 14 through the inlet pipe 51, so that the seine material 11 is carried, while immersed, through the container 5 on its way out of the apparatus 1 (see figure 3) . In a second embodiment of the invention the seine material 11 is sprinkled with impregnating liquid 14 flowing out of the outlet openings of the inlet pipe 51, which may have, in this embodiment, the form of nozzles 51a which are directed directly towards a portion of the conveyance track of the seine material 11, preferably early in the course of the conveyance track through the container 5, so that excess impregnating liquid has the possibility of being collected in the container 5.

It is obvious to a person skilled in the art that it is beneficial to let the seine material 11 dry after cleaning. Naturally, this may take place on the wind-up roller 4, but it will be obvious to form the wind-up roller 4 as a roller leading the seine material 11 to a drying area, in which the seine material 11 is kept for some time, exposed to sunlight for example .

In farming net cages which are arranged with a net bag, in which, at all times, part of the net bag is at the edge of the net cage to be cleaned/dried/impregnated, it will be obvious to arrange two apparatuses 1 according to the invention, the apparatuses 1 being disposed at two opposite net cage edges. The apparatuses 1 are operated synchronously, one apparatus feeding ready cleaned seine material 11 into the masses of water, whereas the other apparatus is pulling out of the masses of water and cleaning the seine material 11 which has been in the operative position in the masses of water for a period of time.

Claims

C l a i m s

1. A method of treating seine material (11), in particular seine material (11) connected with a net cage for fish farming, c h a r a c t e r i z e d i n that the method comprises the steps of: letting the seine material (11) pass an ultrasonic field (7a) so as to free the seine material (11) of undesired materials; and collecting the released, undesired materials which have been released from the seine material (11) .

2. The method in accordance with claim 1, c h a r a c t e r i s e d i n that the ultrasonic field (7a) is provided by an ultrasound source (7) extending substantially across the entire width of a conveyance track for the seine material (11) under treatment .

3. The method in accordance with claim 1, c h a r a c t e r i z e d i n that the ultrasonic field (7a) is provided in a container (5) filled with a cleaning liquid (13) .

4. The method in accordance with claims 1 and 2 , c h a r a c t e r i z e d i n that the collecting of the released, undesired materials is carried out by the cleaning liquid (13) in the container (5) being circulated through a connected circulation circuit which is provided with a separating system (55) which is arranged to separate the released, undesired materials from the cleaning liquid (13) .

5. The method in accordance with claims 1 and 2, c h a r a c t e r i z e d i n that the cleaning liquid (13) is water-based. -L £

6. The method in accordance with claim 1, c h a r a c t e r i z e d i n that the method further includes the step of: supplying an impregnating agent (14) to the seine material (11) .

7. The method in accordance with claim 6, c ha r a c t e r i z e d i n that the impregnating agent (14) is supplied to the seine material (11) after it has passed through the ultrasonic field (7a) .

8. The method in accordance with claim 6, c h a r a c t e r i z e d i n that the impregnating agent (14) is supplied to the seine material (11) by immersion of the seine material (11) into an impregnation pool (5) .

9. The method in accordance with claim 6, c ha r a c t e r i z e d i n that the impregnating agent (14) is sprayed over the seine material (11) .

10. The method in accordance with claim 1 or 6 , c h a r a c t e r i z e d i n that the method includes the steps of: before the seine material (11) is submerged into the cleaning liquid (13), lifting the seine material (11) out of a body of water, in which it has been in an operative position; and after treatment of the seine material (11) , returning the seine material (11) into an operative position in the body of water.

11. The method in accordance with any one of the preceding claims, c ha r a c t e r i z e d i n that, subsequent to at least cleaning, the seine material (11) is stored temporarily in a storage in which it undergoes an after-treatment comprising drying.

12. The method in accordance with claim 1, c h a r a c t e r i z e d i n that the sound frequency lies in the range of 10 kHz - 50 kHz.

13. The method in accordance with claim 1, c ha r ac t e r i z e d i n that the sound frequency lies in the range of 20 kHz - 35 kHz.

14. Apparatus (1) for cleaning seine material (11), in particular seine material (11) connected with a net cage for fish farming, c ha r a c t e r i z e d i n that it includes an ultrasound source (7), a container (5) which is arranged to hold a liquid (13, 14) , a conveyance track for the seine material (11), arranged to carry the seine material (11) through the container (5) , and means (3, 4, 6) for moving the seine material (11) along the conveyance track; the ultrasound source (7) being arranged to be placed in a submerged manner in the container (5), and the conveyance track including at least one portion which is submerged, in an operative position, in a cleaning liquid (13) and is arranged to move the seine material (11) past the ultrasound source (7) at a defined distance and parallel thereto.

15. The apparatus (1) in accordance with claim 14, c ha r a c t e r i z e d i n that the ultrasound source (7) is arranged to provide a sound frequency in the range of 10 kHz - 50 kHz.

16. The apparatus in accordance with claim 14, c ha r a c t e r i z e d i n that the ultrasound source (7) is arranged to provide a sound frequency in the range of 20 kHz - 35 kHz.

17. The apparatus (1) in accordance with claim 14, c ha r a c t e r i z e d i n that the container (5) is connected in a fluid-communicating manner to a circulation circuit including a separating system (55) which is arranged to separate undesired materials and substances from said cleaning liquid (13).

18. The apparatus (1) in accordance with claim 14, c h a r a c t e r i z e d i n that said cleaning liquid is water-based.

19. The apparatus (1) in accordance with claim 14, c ha r a c t e r i z e d i n that the means ( 3 , 4 , 6) for conveying the seine material (11) includes one or more wind-up rollers (4) .

20. The apparatus (1) in accordance with claim 14, c ha r a c t e r i z e d i n that it is provided with a device for supplying a liquid impregnating agent (14) to the seine material (11) .

21. The apparatus (1) in accordance with claim 20, c ha r a c t e r i z e d i n that the device for supplying an impregnating agent (14) is constituted by a container (5) which is arranged to hold the impregnating agent (14) , and that the conveyance track for the seine material (11) includes at least one portion which is submerged, in an operative position, in the impregnating agent (14).

22. The apparatus (1) in accordance with claim 20, c h a r a c t e r i z e d i n that the means for supplying an impregnating agent (14) is constituted by a dosing system including one or more nozzles (51a) which is/are arranged to distribute the impregnating agent (14) across the entire width of the conveyance track.

23. The apparatus (1) in accordance with claim 20, c h a r a c t e r i z e d i n that to the device for supplying an impregnating agent (14) to the seine material (11) is/are connected one or more devices (5, 53, 54) for collecting and recirculating excess impregnating agent (14) which has been released from the treated seine material (11) .