Apparatus and system for delousing of infested fish and method for use of same

Abstract

Apparatus (1) for guiding a fish by gravity past a treatment area (15) for killing or injuring an external parasite on the fish (9) The apparatus (1) comprises: - an inlet portion (10) and an outlet portion (20); - an elongated base (2) from the inlet portion (10) to the outlet portion (20), the elongated base (2) forms a treatment face (20) and an opposite back side (29); - a plurality of through openings (21) in the elongated base (2) from the back side (29) to the treatment face (20); and - a hot gaseous fluid generator (4) adapted to pass hot gaseous fluids (41) through the plurality of through openings (21) in the treatment area (15) between the inlet portion (10) and the outlet portion (19). A system (6) comprising the apparatus (1) and a method for operating the apparatus (1) are described as well.

Description

[0001] APPARATUS AND SYSTEM FOR DELOUSING OF INFESTED FISH AND METHOD FOR USE OF SAME

[0002] This invention concerns an apparatus and a system for rapid treatment of fish infected with external parasites. The fish may be a salmonoid fish and the external parasite may be a crustacean parasite such as Lepeophtheirus salmonis and Caligus spp. More particularly the apparatus and system concern to treat fish separated from water with hot air or with steam or with a mixture of hot air and steam for a short period of time, such as between 2 and 10 seconds. The hot air or steam or the mixture of hot air and may be lethal to the external parasite or cause at least injury to the parasite such that the parasite drops off the skin or is no longer able to feed on mucus and skin. The mucus of the fish protects the fish from the short exposure of the hot air or steam or the mixture of hot air and steam. Even more particularly the fish slides by gravity on a base past a treatment area where the fish is exposed to the hot air or steam or the mixture of hot air and steam. In one embodiment the base is kept cool by a coolant. The fish slides into a water-filled basin after treatment. The fish passes through the system in less than one minute, such as less than 45 seconds, such as less than 30 seconds. The invention also concerns a method for treatment of fish infected by an external parasite by exposing the fish and the external parasite to hot air or steam or the mixture of hot air and steam.

[0003] Efficient and cost-effective farming of species in the Salmonidae fish family is often marred by the presence of sea lice in the water. Many efforts have been made to reduce and try to eliminate sea lice from commercial fish farms.

[0004] One known method is to pump volumes of water and fish onto a vessel where the fish can be cleaned of sea lice using various known techniques and then delivered back to the water to continue growing. The water is then typically cleaned of sea lice by passing the water through a drum filter which catches the sea lice such that they can be disposed of. Such known out-of-water treatment techniques comprise warm water bath treatment, water jets and brushes.

[0005] The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

[0006] The object is achieved through features, which are specified in the description below and in the claims that follow.

[0007] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0008] In a first aspect the invention relates more particularly to an apparatus for guiding fish by gravity past a treatment area for killing or injuring an external parasite on a fish. The apparatus comprises:

[0009] - an inlet portion and an outlet portion;

[0010] - an elongated base from the inlet portion to the outlet portion, the elongated base forms a treatment face and an opposite back side;

[0011] - a plurality of through openings in the elongated base from the back side to the treatment face; and

[0012] - a hot gaseous fluid generator adapted to pass hot gaseous fluids through the plurality of through openings in a treatment area between the inlet portion and the outlet portion.

[0013] The elongated base may be formed by lengthy ribs positioned side by side, and the lengthy ribs have a first end at the inlet portion and a second end at the outlet portion.

[0014] The lengthy ribs may pairwise form a slit between them, and the slits may form the plurality of through openings.

[0015] The hot gaseous fluid generator may be adapted to generate hot gaseous fluids comprising one of:

[0016] - a steam, comprising one of a wet steam, a dry steam, a saturated steam and a super- heated steam;

[0017] - a hot air; and

[0018] - a mixture of a steam and a hot air.

[0019] The hot gaseous fluid generator may be fluidly connected to a plurality of nozzles positioned at the through openings.

[0020] The apparatus may comprise:

[0021] - a cooling means for the base; and

[0022] - a cooling device providing a coolant to the cooling means.

[0023] The cooling means may comprise hollow lengthy ribs. The first end may be fluidly connected to a first manifold. The second end may be fluidly connected to a second manifold.

[0024] The first manifold and the second manifold may be fluidly connected to the cooling device, such that the coolant circulates through the elongated ribs.

[0025] In an alternative embodiment the elongated base may be formed by two plates spaced apart. The plurality of through openings may be holes or elongated apertures in the plate forming the treatment face.

[0026] In an alternative embodiment the first end of the two plates may be fluidly connected to a first manifold. The second end may of the two plates may be fluidly connected to a second manifold. The first manifold and the second manifold may be fluidly connected to the cooling device, such that the coolant circulates between the two plates.

[0027] The coolant may comprise water, such as sea water. The sea water may be sourced directly from an adjacent sea water body.

[0028] The base may be trough shaped. This has the advantage that fish sliding downwards by gravity may be guided by the trough shape. In an alternative embodiment the base is circular shaped or close to circular shaped.

[0029] The apparatus may be positioned internally in a frame. The frame may comprise at least one tight wall. The frame may comprise a tube. The frame has the advantage that the hot gaseous fluids remain inside the apparatus, and this may save energy. In a second aspect the invention relates more particularly to a system for treating fish infested with an external parasite, wherein the system comprises:

[0030] - an apparatus as described herein, wherein the inlet portion is elevated compared to the outlet portion;

[0031] - a separation unit at the inlet, the separation unit is adapted to separate fish from water, and the separation unit is adapted to guide the fish onto the elongated base;

[0032] - a fish transporter adapted to transport fish from a body of water to the separation unit; and

[0033] - a water-filled basin for the fish at the outlet.

[0034] The fish transporter may comprise a fish pump.

[0035] The separation unit may be positioned elevated to the inlet portion to guide fish by gravity onto the base.

[0036] The body of water may be a fish pen. The body of water may be a receptacle. The body of water may be a well in a well boat.

[0037] In a third aspect the invention relates more particularly to a method for treating fish infested with an external parasite. The method comprises the steps of:

[0038] - providing the system as described herein;

[0039] - provide a fish in need of treatment;

[0040] - transport the fish from the body of water into the separation unit and drain water from the fish;

[0041] - guide the fish from the separation unit and onto the elongated base on the treatment face;

[0042] - let the fish slide by gravity past the treatment area;

[0043] - generate the hot gaseous fluid and pass the hot gaseous fluid through the through openings such that the hot gaseous fluid contacts a surface of the fish;

[0044] - let the fish slide into the water-filled basin; and

[0045] - keep the base cool by use of the cooling means. The hot gaseous fluid may comprise hot air at a temperature of between 80 °C and

[0046] 300 °C, such as between 80 °C and 250 °C, such as between 80 °C and 200 °C, such as between 80 °C and 150 °C.

[0047] The hot gaseous fluid may comprise steam at a temperature of between 100 °C and 300 °C, such as such as between 100 °C and 250 °C, such as between 100 °C and 200 °C, such as between 80 °C and 175 °C.

[0048] The hot gaseous fluid may comprise a mixture of hot air and steam at a temperature of between 100 °C and 300 °C, such as such as between 100 °C and 250 °C, such as between 100 °C and 200 °C, such as between 80 °C and 175 °C.

[0049] The elongated base may be kept cool by flowing water of from 0 °C to 20 °C through the hollow ribs.

[0050] The temperature of the water in the water-filled basin may be within a range of ± 5 °C of the temperature of the body of water.

[0051] The residence time for the fish within the system is much shorter than by other known out-of-water techniques for treating infected fish. This causes comparable less stress to the fish. Due to the short treatment, the capacity is better, which means that the fish is treated more rapidly after being crowded by a sweep net in a fish pen. Le., the fish experience a shorter period in the crowded state, and this reduces the stress to the fish as well.

[0052] The fish in need of treatment may be a salmonoid fish. The salmonoid fish may be Atlantic salmon. The salmonoid fish may be rainbow trout. The external parasite may be a crustacean parasite. The crustacean parasite may be a sea lice.

[0053] In the following is described an example of a preferred embodiment illustrated in the accompanying drawings, wherein:

[0054] Fig. 1 shows schematically an apparatus and a system for killing or injuring an external parasite on a fish; Fig. 2 shows the same as figure 1 and a frame that houses the elongated base; and

[0055] Fig. 3 shows in a larger scale schematically a base with hollow lengthy ribs.

[0056] In the figures, same or corresponding elements are indicated by same reference numerals. For clarity reasons, some elements may in some of the figures be with-out reference numerals.

[0057] A person skilled in the art will understand that the figures are just principal drawings. The relative proportions of individual elements may also be distorted.

[0058] In the drawings, the reference numeral 1 indicates an apparatus for guiding fish 9 by gravity past a treatment area 15 for killing or injuring an external parasite on a fish 9. The apparatus 1 comprises an inlet portion 10 and an outlet portion 19. An elongated base 2 is formed between the inlet portion 10 and the outlet portion 19. The elongated base 2 forms a treatment face 20 (see figure 3) and an opposite back side 29. In one embodiment the base 2 is trough shaped (see figure 3).

[0059] The apparatus 1 is depicted with an optional cooling means 3 for the base 2. A cooling device 33 provides a coolant 35 to the cooling means 3.

[0060] The apparatus 1 comprises a plurality of through openings 21 in the elongated base 2 from the back side 29 to the treatment face 20.

[0061] The apparatus 1 comprises a hot gaseous fluid generator 4 adapted to pass hot gaseous fluids 41 through the plurality of through openings 21 in the treatment area 15 between the inlet portion 10 and the outlet portion 19.

[0062] The elongated base 2 is shown formed by lengthy ribs 5 positioned side by side, and the lengthy ribs 5 have a first end 50 at the inlet portion 10 and a second end 59 at the outlet portion 19. The lengthy ribs 5 form pairwise a slit 51 between them, and the slits 51 form the plurality of through openings 21. The lengthy ribs 5 may in one embodiment be hollow as seen in figure 3 and each lengthy rib 5 may comprise a cavity 53. The cooling means 3 may in one embodiment comprise the hollow lengthy ribs 5 and the first end 50 is fluidly connected to a first manifold 31, and the second end 59 is fluidly connected to a second manifold 32. The first manifold 31 and the second manifold 32 are fluidly connected to the cooling device 33, such that the coolant 35 circulates through the elongated ribs 5 in the cavity 53.

[0063] The coolant 35 may in one embodiment comprise water such as sea water. The cooling device 33 may comprise a pump (not shown). The cooling device 33 may pump water or sea water from a body of water 65. The water or sea water have a temperature between 0 °C and 20 °C. After the coolant 35 has passed through the lengthy ribs 5, the coolant 35 may be discharged to the body of water 65. In other embodiments the coolant may have passed through the elongated base 2 or over the elongated base 2.

[0064] The hot gaseous fluid 41 may be steam. The steam may be a wet steam. The steam may be a dry steam. The steam may be a saturated steam. The steam may be a superheated steam. The hot gaseous fluid 41 may be a hot air. The hot gaseous fluid 41 may be a mixture of steam and hot air. The steam may have a temperature of between 100 °C and 300 °C. The hot air may have a temperature of between 80 °C and 300 °C. The mixture of steam and hot air may have a temperature of between 100 °C and 300 °C. The hot gaseous fluid generator 4 may be a steam generator as known in the art. The hot gaseous fluid generator 4 may be a hot air generator as known in the art.

[0065] The hot gaseous fluid generator 4 is fluidly connected to a plurality of nozzles 43 positioned at the through openings 21. The nozzles 43 direct hot gaseous fluid 41 to the treatment area 15 on the treatment face 20.

[0066] The apparatus 1 may be positioned internally in a frame 16 as seen in figure 2. The frame 16 may in one embodiment be a tube. The frame 16 may in an alternative embodiment be box shaped. The frame 16 comprises at least one tight wall 17.

[0067] The apparatus 1 is part of a system 6 for treating fish 9 infested with an external parasite. The inlet portion 10 is elevated compared to the outlet portion 19. A separation unit 61 is positioned at the inlet 10. The separation unit 61 is adapted to separate fish 9 from water as known in the art. The separation unit 61 is adapted to guide the fish 9 onto the elongated base 2. A fish transporter 63 is adapted to transport fish 9 from a body of water 65 to the separation unit 61. The fish transporter 63 may be a fish pump as known in the art. The separation unit 61 is positioned elevated compared to the inlet portion 10. Thereby the fish 9 are guided by gravity onto the base 2.

[0068] The system 6 further comprises a water-filled basin 67. The fish 9 slide past the treatment area 15 on the treatment face 20, through the outlet portion 19 and into the water-filled basin 67.

[0069] The body of water 65 may be a body of water 65 within a fish pen (not shown). The body of water 65 may be a body of water 65 within a receptacle. The body of water 65 may be a body of water 65 within a well in a well boat (not shown).

[0070] The water-filled basin 67 may be a fish pen (not shown). The water-filled basin 67 may be a receptacle. The water-filled basin 67 may be a well in a well boat (not shown).

[0071] Fish 9 to infested by an external parasite is transported from the body of water 65 onto the separation unit 61 by the fish transporter 63. The fish transporter 63 comprises a fish pump 64. Water is from the fish 9 when the fish 9 pass over the separation unit 61. The separation unit 61 guides the fish 9 onto the elongated base 2 and more specifically onto the treatment face 20. The fish 9 slide by gravity past the treatment area 15.

[0072] Hot gaseous fluid 41 is generated by the hot gaseous fluid generator 4, and the hot gaseous fluid 41 is passed through the through openings 21 such that the hot gaseous fluid 41 contacts a surface 91 of the fish 9. The fish 9 further slide into the water-filled basin 67.

[0073] The base 2 is in one embodiment kept cool by use of the cooling means 3.

[0074] The difference in height between the inlet 10 and the outlet 19 is adjustable. Thereby the residence time of the fish 9 on the treatment face 20 and in particular the time the fish use to pass the nozzles 43 spraying hot gaseous fluid onto the surface 91 of the fish 9, can be adjusted in a simple manner. The residence time should be sufficient to injure or kill the external parasite and short enough to not cause burns to the fish 9. The fish 9 is in contact with the treatment face 20. The treatment face 20 is kept cool by the cooling means 3. In addition, the fish is covered by mucus. The mucus comprises mostly water, and evaporation of the water protect the skin from being burnt. In addition, the residence time is short, such as between 2 and 10 seconds, and the fish 9 may immediately be dropped into a water-filled basin 67. The water in the water-filled basin 67 may have a temperature of between 0 °C and 20 °C, which will immediately chill the fish 9.

[0075] The residence time is much shorter than by other known out-of-water techniques for treating infected fish 9. This causes comparable less stress to the fish 9. Due to the short treatment, the capacity is better, which means that the fish 9 is treated more rapidly after being crowded by a sweep net in a fish pen. Le., the fish 9 experience a shorter period in the crowded state, and this reduces the stress to the fish 9 as well.

[0076] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0077] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

C l a i m s1. Apparatus (1) for guiding a fish (9) by gravity past a treatment area (15) for killing or injuring an external parasite on the fish (9), c h a r a c t e r i s e d i n that the apparatus (1) comprises:- an inlet portion (10) and an outlet portion (19);- an elongated base (2) from the inlet portion (10) to the outlet portion (19), the elongated base (2) forms a treatment face (20) and an opposite back side (29);- a plurality of through openings (21) in the elongated base (2) from the back side (29) to the treatment face (20); and- a hot gaseous fluid generator (4) adapted to pass hot gaseous fluids (41) through the plurality of through openings (21) in the treatment area (15) between the inlet portion (10) and the outlet portion (19).

2. The apparatus (1) according to claim 1, wherein the elongated base (2) is formed by lengthy ribs (5) positioned side by side, and the lengthy ribs (5) have a first end (50) at the inlet portion (10) and a second end (59) at the outlet portion (19).

3. The apparatus (1) according to claim 2, wherein the lengthy ribs (5) pairwise form a slit (51) between them, and the slits (51) form the plurality of through openings (21).

4. The apparatus (1) according to any one of the preceding claims, wherein the hot gaseous fluid generator (4) is adapted to generate hot gaseous fluids (41) comprising one of:- a steam, comprising one of a wet steam, a dry steam, a saturated steam and a superheated steam;- a hot air; and- a mixture of a steam and a hot air.

5. The apparatus (1) according to any one of the preceding claims, wherein the hot gaseous fluid generator (4) is fluidly connected to a plurality of nozzles (43) positioned at the through openings (21).

6. The apparatus (1) according to any one of the preceding claims, wherein the apparatus (1) comprises:- a cooling means (3) for the base (2); and- a cooling device (33) providing a coolant (35) to the cooling means (3).

7. The apparatus (1) according to claim 6, wherein the cooling means (3) comprises hollow lengthy ribs (5) and the first end (50) is fluidly connected to a first manifold (31), and the second end (59) is fluidly connected to a second manifold (32), and the first manifold (31) and the second manifold (32) are fluidly connected to the cooling device (33), such that the coolant (35) circulates through a cavity (53) in the elongated ribs (5).

8. The apparatus (1) according to any one of the preceding claims, wherein the coolant (35) comprises water.

9. The apparatus (1) according to any one of the preceding claims, wherein the base (2) is trough shaped.

10. The apparatus (1) according to any one of the preceding claims, wherein the apparatus (1) is positioned internally in a frame (16).

11. The apparatus (1) according to claim 10, wherein the frame (16) comprises at least one tight wall (17).

12. A system (6) for treating fish (9) infested with an external parasite, wherein the system comprises:- an apparatus (1) according to any one of the claims 1 to 11, wherein the inlet portion (10) is elevated compared to the outlet portion (19);- a separation unit (61) at the inlet portion (10), the separation unit (61) is adapted to separate fish (9) from water, and the separation unit (61) is adapted to guide the fish (9) onto the elongated base (2);- a fish transporter (63) adapted to transport fish (9) from a body of water (65) to the separation unit (61); and- a water-filled basin (67) for the fish (9) at the outlet portion (19).

13. The system (6) according to claim 12, wherein the fish transporter (63) comprises a fish pump (64).

14. The system (6) according to claim 12 or claim 13, wherein the separation unit (61) is positioned elevated to the inlet portion (10) to guide fish (9) by gravity onto the base (2).

15. The system (6) according to any one of the claims from 12 to 14, wherein the body of water (65) is one of a fish pen, a receptacle and a well in a well boat.

16. The system (6) according to any one of the claims from 12 to 15, wherein the water-filled basin (67) is one of a fish pen, a receptacle and a well in a well boat.

17. Method for treating fish (9) infested with an external parasite, c h a r a c t e r i s e d i n that the method comprises the steps of:- providing the system (6) according to any one of the claims 12 to 16;- provide the fish (9) in need of treatment;- transport the fish (9) from the body of water (65) onto the separation unit (61) and drain water from the fish (9);- guide the fish (9) from the separation unit (61) and onto the elongated base (2) on the treatment face (20);- let the fish (9) slide by gravity past the treatment area (15);- generate the hot gaseous fluid (41) and pass the hot gaseous fluid (41) through the through openings (21) such that the hot gaseous fluid (41) contacts a surface (91) of the fish (9);- let the fish (9) slide into the water-filled basin (67); and- keep the base (2) cool by use of the cooling means (3).

18. The method according to claim 17, wherein the hot gaseous fluid (41) comprises hot air at a temperature of between 80 °C and 300 °C.

19. The method according to claim 17, wherein the hot gaseous fluid (41) comprises steam at a temperature of between 100 °C and 300 °C.

20. The method according to any one of the claims from 17 to 19, wherein the elongated base (2) is kept cool by flowing coolant of from 0 °C to 20 °C through cavities (53) in the hollow ribs (5).

21. The method according to any one of the claims from 17 to 20, wherein the tem- perature of the water in the water-filled basin (67) is within a range of ± 5 °C of the temperature of the body of water (65).

22. The method according to any one of the claims from 17 to 21, wherein the fish (9) in need of treatment is a salmonoid fish.

23. The method according to any one of the claims from 17 to 21, wherein the ex- ternal parasite is a crustacean parasite.

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