Note: Descriptions are shown in the official language in which they were submitted.
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Module, system and method for delousing fish
Technical field
The disclosure relates to the field of fish farming.
Background
[0001] Delousing of fish is generally performed in circular pipes with pipe
dimensions
around 250 to 300 mm in diameter. The relatively small pipe diameters are
largely used in order to prevent multiple fish from being transported through
the
pipe simultaneously, thus preventing overlap and making the distance from the
pipe wall to the fish relatively short and predictable. Injecting and
withdrawing
water can be done evenly around the fish without affecting its position,
making it
possible to use water nozzles to clean and delouse fish using relatively low
water
pressures.
[0002] A problem with delousing fish in circular pipes, however, is that it is
difficult to
scale up in order to meet the demand for higher capacities. One cannot simply
increase the diameter of the pipe, as the latter will result in overlap of
fish and
hence cause irregular and inefficient delousing treatment. The use of large
circular pipes may for example block the treatment of another fish making the
treatment for each individual fish dependent on the exact position of the fish
within the pipe.
[0003] To meet the demand for higher capacities in delousing systems, the
prevailing
solution has been to install multiple treatment systems/lines in parallel.
Each
additional line here adds a bit less than its rated capacity, as the lines can
be
hard to balance with flow and fish entry. Each additional line also requires a
complete set of the necessary equipment for performing delousing, including
for
example, pumps, sensors, electronics, and piping, and consequently also comes
with the associated costs and space requirements. Connecting multiple
treatment
lines to larger diameter pipes is especially problematic as it requires
splitting of
the flow and additional handling. The latter is known in the art to increase
the
risk of injuries inflicted on the fish and to cause blockages of the system.
[0004] N020160800A1 describes a system for delousing fish, comprising a source
of lice
infected fish, a pump device arranged for transporting fish from said source
to a
delousing module, a warm water source arranged to provide lukewarm water to
the delousing module.
[0005] N0339015 disclose a plant for removal of ectoparasites from live fish.
The plant
includes a receival unit for live fish and for sieving away water followed by
a lice
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removal station with rotary brushes and water jets configured for mechanical
removal of the ectoparasites attached to the surface of the fish.
[0006] The present disclosure aims to provide an alternative to the above-
mentioned
solutions for how to perform delousing of fish at a large scale with
consistent
results.
Summary of the disclosure
[0007] A first aspect of the present disclosure provides a module for
delousing fish, the
module comprising a pipe segment for conducting water containing fish, where
the pipe segment comprises a pipe segment top wall and a pipe segment bottom
wall, and a delousing means for removing sea lice from a fish being conducted
through the pipe segment, where the delousing means is arranged in or at the
pipe segment top wall and/or in or at the pipe segment bottom wall, where the
pipe segment has a transverse cross section with a maximum height h and a
maximum width w, and where w > 2h.
[0008] In an embodiment of the disclosure the pipe segment top wall and the
pipe
segment bottom wall are planar.
[0009] In another embodiment of the disclosure the pipe segment top wall and
the pipe
segment bottom wall are arranged in parallel to each other and at a distance h
from each other.
[0010] In yet another embodiment of the disclosure the pipe segment further
comprises
two pipe segment side walls, and where the two pipe segment side walls are
arranged at a distance w from each other.
[0011] In yet another embodiment of the disclosure the two pipe segment side
walls are
planar and parallel to each other, and where the pipe segment has a
rectangular
pipe profile.
[0012] In yet another embodiment of the disclosure the delousing means
comprises a
water nozzle.
[0013] In yet another embodiment of the disclosure the water nozzle comprises
an
elongate slit.
[0014] In yet another embodiment of the disclosure the delousing means
comprises a
water nozzle arranged in or at the pipe segment top wall, and a water nozzle
arranged in or at the pipe segment bottom wall.
[0015] In yet another embodiment of the disclosure the module further
comprises a
water outlet positioned upstream or downstream from the nozzle, and where the
outlet is in fluid communication with the water nozzle.
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[0016] In yet another embodiment of the disclosure the delousing means
comprises a
brush, a laser, a sound emitter or an ultrasound emitter.
[0017] In yet another embodiment of the disclosure h is in the range from 100
mm to
500 mm, preferably in the range from 150 mm to 400 mm and most preferably
in the range from 200 - 300 mm.
[0018] A second aspect of the present disclosure provides a modular pipe
system for
delousing fish, the modular pipe system comprising a module according to any
embodiment of the first aspect of the disclosure, a first coupling unit for
connecting a first end of the module to a circular pipe, and a second coupling
unit
for connecting a second end of the module to a circular pipe, where the
module,
the first coupling unit and the second coupling unit are connected in series,
with
the first coupling unit and the second coupling unit positioned at each end.
[0019] In an embodiment of the disclosure the module further comprises an
auxiliary
module, where the auxiliary module, the module, the first coupling unit and
the
second coupling unit are connected in series, with the first coupling unit and
the
second coupling unit positioned at each end, the auxiliary module comprising
an
auxiliary module pipe segment for conducting water containing fish, where the
auxiliary module pipe segment comprises an auxiliary module pipe segment top
wall and an auxiliary module pipe segment bottom wall, and a water draining
means for extracting water from the auxiliary module pipe segment, where the
water draining means is arranged in or at the auxiliary module pipe segment
top
wall and/or in or at the auxiliary module pipe segment bottom wall, and/or a
water injection means for injecting water into the auxiliary module pipe
segment,
where the water injection means is arranged in or at the auxiliary module pipe
segment top wall and/or in or at the auxiliary module pipe segment bottom
wall,
where the auxiliary module pipe segment has a second transverse cross section
having the same shape as the transverse cross section of the pipe segment.
[0020] A third aspect of the present disclosure provides a method for
delousing fish, the
method comprising the steps of providing a module according to any embodiment
of the first aspect of the disclosure or any embodiment of the second aspect
of
the disclosure, conducting water containing a fish through the pipe segment of
the module, and delousing the fish using the delousing means of the module.
[0021] In an embodiment of the disclosure the water is conducted through the
pipe
segment of the module with a velocity from 1.5 m/s to 2.5 m/s.
[0022] Other advantageous features will be apparent from the accompanying
claims.
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Brief description of the drawings
[0023] In order to make the disclosure more readily understandable, the
description that
follows will refer to accompanying drawings, in which:
[0024] Figure 1 is a schematic representation of a module for delousing fish
where the
delousing means comprises a water nozzle,
[0025] Figure 2 is a schematic representation of a module for delousing fish
where the
delousing means comprises a brush,
[0026] Figure 3 is a schematic representation of a module for delousing fish
where the
delousing means comprises a laser, a sound emitter, or an ultrasound emitter,
[0027] Figure 4 is a schematic representation of a module for delousing fish
where the
delousing means comprises a water nozzle, and where the module comprises a
water outlet,
[0028] Figure 5 is a schematic representation of a system for delousing fish
where the
system comprises a module for delousing fish, a first coupling unit, a second
coupling unit, a first auxiliary module and a second auxiliary module, and
[0029] Figure 6 is a schematic representation of a method for delousing fish.
Detailed description of the disclosure
[0030] In the following, general embodiments as well as particular exemplary
embodiments of the disclosure will be described. References will be made to
the
accompanying drawings. It shall be noted, however, that the drawings are
exemplary embodiments only, and that other features and embodiments may
well be within the scope of the disclosure as claimed. The drawings are
schematical drawings not drawn to scale.
[0031] Unless otherwise defined, all terms of art, notations and other
scientific terms or
terminology used herein are intended to have the meanings commonly
understood by those of skill in the art to which this disclosure pertains.
Certain
terms of art, notations, and other scientific terms or terminology may,
however,
be defined specifically as indicated below.
[0032] The present disclosure provides a module 100 for delousing fish, a
modular pipe
system for delousing fish and a method for delousing fish. The module 100,
system and method are each based on the concept of performing delousing of
fish in a pipe segment 105 having an elongate transverse cross section 107.
The
elongate transverse cross section 107 may here be understood as a plane cross
section 107 of the pipe segment 105 that is normal on the downstream average
flow direction 160 in the pipe segment, for example the flow direction of
water
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between conducted through the pipe segment 105. The latter is schematically
illustrated in figure 1.
[0033] Figure 1 shows a schematic illustration of module 100 for delousing
fish
according to the present disclosure. The module 100 here comprises a pipe
segment 105 and a delousing means 120.
[0034] The pipe segment is according to the disclosure configured to conduct
water
containing fish. The pipe may thus for example be a pipe made from a metal
such as steel, aluminium alloy, titanium alloy, or another suitable alloy.
Alternatively, the pipe segment may be made, at least in part, from a polymer
such as Acrylonitrile Butadiene Styrene (ABS), Chlorinated Polyvinyl Chloride
(CPVC), High-Density Polyethylene (HDPE), polybutylene (PB-1), polyethylene
(PE), cross-linked polyethylene (PEX), polypropylene (PP), Polyvinylidene
Difluoride (PVDF), Unplasticized Polyvinyl Chloride (UPVC). The pipe is
preferably
completely watertight.
[0035] Figure 1 schematically illustrates a pipe segment 105 according to the
disclosure,
where the pipe segment 105 has a transverse cross section 107 with a maximum
height h and a maximum width w. The maximum height h and the maximum
width w are here chosen such that w 2h. The pipe segment 105 may thus be
consider as generally having an elongate transverse cross section 107 with a
width w that is at least twice the size of the height h. What is considered as
the
height relative to what is considered the width of the elongate transverse
cross
section 107, i.e. the pipe segment 105, will be appreciated by a person
skilled in
the art to generally be arbitrary. The pipe segment 105 may for example be
rotated, meaning that the width w and the height h may be interchanged. The
direction of the width and the direction of the height will nevertheless be
considered as being normal to each other. A person skilled in the art with
knowledge of the present invention will appreciate that the height of the pipe
segment cross section 107 generally may be considered as the vertical
direction
of the pipe segment cross section 107. The width w and the height h of the
transverse cross section 107 of the pipe segment 105 may herein be considered
as the same as the width w and the height h the pipe segment 105 respectively.
[0036] The width to height ratio, w/h, of the pipe segment is according to the
disclosure
such that w 2h. In a preferred embodiment, the width to height ratio of the
pipe segment is such that w 3h, or even more preferred such that w 4h. A
width of the pipe segment being larger than 3 times the height is preferred as
such a width is adapted to the typical present flow requirements for a
delousing
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system for fish, particularly for salmon. The dimensions of the pipe segment
may
generally be adapted to the dimensions of the piping used by for example fish
carriers and bilge well vessels, which typically employ circular piping with
diameters of 500 mm and larger, i.e. a cross section of roughly 200000 mm2 and
larger. For a pipe segment with a height of 250 mm (which is a typical
desirable
height for the pipe segment as will be described later) it will consequently
be
required to have a width of at least 3 times the height in order to match the
cross section of circular piping with diameters of 500 mm. A width to height
ratio
of the pipe segment being such that w 4h is preferred for even larger systems.
[0037] Figure 1 is a schematic illustration of a pipe segment 105 of a module
100 for
delousing fish, where the pipe segment 105 comprises a pipe segment top wall
110 and a pipe segment bottom wall 115. A person skilled in the art will
appreciate that said walls 110,115 do not need to be separate walls, but that
they may both be a part of continuous wall. The latter will for example be the
case for a pipe segment 105 with a transverse cross section 107 being oval,
elliptical, or another elongate continuous structure. The height h of the pipe
segment 105 may generally be considered as the maximum separation distance
between the pipe segment top wall 110 and a pipe segment bottom wall 115. The
maximum height h of the pipe segment 105 may generally be chosen according
to the size of the fish that is to be deloused in the module 100. The maximum
height h of the pipe segment 105 may in other words be chosen such that the
height h is slightly larger than the maximum height of the fish to be treated.
The
latter allows for a fish to pass through the pipe segment 105 with a similar
distance to the top wall 110 and the bottom wall 115 of the pipe segment 105
while at the same time not touching any of the said walls 110,115. A small
clearing between the fish and the top wall 110 and bottom wall 115 of the pipe
segment 105 is preferred, as this will enable predictable conditions for
delousing
using the delousing means 120. The clearing distance between the fish and any
of the top wall 110 and bottom wall 115 of the pipe segment 105 may for
example be in the range 20 mm to 100 mm, or in the range 30 mm to 80 mm, or
alternatively in the range 40 mm to 70 mm. In a particular example, the height
h of the pipe segment 105 may be in the range from 100 mm to 500 mm. In
another example the height h of the pipe segment 105 may be in the range from
150 mm to 400 mm. In yet another example the height h of the pipe segment
105 may be in the range from 200 - 300 mm. A height h of the pipe segment
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105 being in the range 200 - 300 mm, for example 250 mm, has been found to
be particularly suitable when the fish to be treated is salmon or trout.
[0038] The elongate transverse cross section 107 of the pipe segment 105
allows for
multiple fish to swim/be conducted side by side though the pipe segment 105,
while at the same time restricting the number of fish swimming/being conducted
above one another. The height of the pipe segment 105 may further be adjusted
according to the size of the height of the fish, thus hindering overlap of
fish in the
height direction h of the pipe segment 105. The fish being conducted through
the
pipe segment 105 may in the latter case be distributed largely in one plane.
Figure 1 schematically illustrates a particular embodiment of the disclosure
where
the pipe segment top wall 110 and the pipe segment bottom wall 115 are planar.
The latter allows for low turbulence in the pipe segment 105 and similar
conditions close to the top wall 110 and bottom wall 115 of the pipe segment
105.
[0039] The delousing means 120 may according to the present disclosure be any
means
suitable for removing sealice from the skin of a fish being conducted through
the
pipe segment 105. The delousing means 120 may in other words be considered
as configured to remove lice from the skin of a fish being conducted through
the
pipe segment 105. The delousing means 120 may for example comprise a water
nozzle 130, a brush 140, a laser 145, a sound emitter 150 or an ultrasound
emitter 155. The brush 140 may here be a brush 140 configured to be rotated,
for example a cylindrical brush 140 or alternatively a stationary brush 140.
The
ultrasound emitter 155 may here for example be configured to emit ultrasound
into the pipe segment 105 with a frequency that matches the eigenfrequency,
i.e.
resonance frequency, of the sealice to be removed from the fish. In a
particular
embodiment of the disclosure the ultrasound emitter 155 may be configured to
emit a wavelength from 5 mm to 20 mm. The latter is known as the approximate
size of sea lice in the Lepeophtheirus salmonis and Caligus elongatus
families,
and ultrasound with wavelengths in the range 5 mm and 20 mm may result in
standing oscillations in these lice, causing them either to perish or to be
dislodged from the fish. Figure 1 is a schematic representation of a module
100
for delousing fish where the delousing means 120 comprises a water nozzle 130
shaped as a slit. Figure 2 is a schematic representation of a module 100 for
delousing fish where the delousing means 120 comprises a rotating brush 140.
Figure 3 is a schematic representation of a module 100 for delousing fish
where
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the delousing means 120 comprises a laser 145, a sound emitter 150, or an
ultrasound emitter 155.
[0040] The delousing means 120 may as schematically illustrated in figure 1, 2
and 3 be
arranged in or at the pipe segment top wall 110 and/or in or at the pipe
segment
bottom wall 115. The delousing means 120 may for example be incorporated in
the pipe segment top wall 110 and/or in the pipe segment bottom wall 115. An
example of the latter is a water nozzle 130 built into the pipe segment top
wall
110 and/or a water nozzle 130 built into the pipe segment bottom wall 115. A
delousing means 120 arranged at the pipe segment top wall 110 and/or at the
pipe segment bottom wall 115 may be considered as delousing means 120
arranged adjacent to or fastened to the segment top wall 110 and/or at the
pipe
segment bottom wall 115 inside the pipe segment 105. An example of the latter
is a rotating brush 140 positioned inside the pipe segment 105 adjacent to the
pipe segment top wall 110 and/or adjacent to the pipe segment bottom wall 115.
The delousing means 120 may be considered as two separate delousing means
120, comprising delousing means 120 arranged in or at the pipe segment top
wall 110, and delousing means 120 arranged in or at the pipe segment bottom
wall 115.
[0041] Figure 1, 2 and 3 schematically illustrate a particular embodiment of
the
disclosure where the pipe segment top wall 110 and the pipe segment bottom
wall 115 are arranged in parallel to each other. The pipe segment top wall 110
and the pipe segment bottom wall 115 may alternatively be essentially in
parallel
with each other, meaning herein that the pipe segment top wall 110 is inclined
with an angle of less than 10 degrees relative to the pipe segment bottom wall
115. A configuration where the pipe segment top wall 110 and the pipe segment
bottom wall 115 are arranged in parallel, or essentially in parallel to each
other
facilitates similar internal conditions in the pipe segment 105 along the
width of
the pipe segment 105. Delousing means may thus be arranged such that the
delousing effect becomes largely unaffected by the exact position of the fish
to be
treated along the width of the pipe segment 105. In the embodiment where the
pipe segment top wall 110 and the pipe segment bottom wall 115 are arranged in
parallel to each other, the distance from the pipe segment top wall 110 to the
pipe segment bottom wall 115 will be equal to h, i.e. the height of the pipe
segment 105.
[0042] Figure 1, 2, 3 and 4 schematically illustrate an embodiment of the
disclosure
where the pipe segment 105 further comprises two pipe segment side walls 125,
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and where the two pipe segment side walls 125 are arranged at a maximum
distance w from each other. The two pipe segment side walls 125 may, as
illustrated in figure 1, 2, 3 and 4 be planar and parallel to each other. The
figures
1, 2, 3 and 4 also schematically illustrate a particular embodiment of the
disclosure where the pipe segment 105 has a rectangular pipe profile. The
latter
design is preferable as this enables the pipe segment 105 to be constructed
using
plates. The latter has inter alia the potential to reduce cost of
manufacturing the
module 100 relative to using a circular pipe segment.
[0043] Figure 1 schematically illustrates an embodiment of the disclosure
where the
delousing means 120 comprises a water nozzle 130. The water nozzle 120 may
here generally be considered as configured to inject water onto fish being
conducted through the pipe segment 105 in order to delouse the fish. The water
nozzle 120 may here for example comprise an opening in the top wall 110 and/or
bottom wall 115 of the pipe segment 105. Alternatively, the water nozzle 120
may comprise a separate nozzle being integrated in the top wall 100 and/or
bottom wall 115 of the pipe segment 105 or a separate nozzle being arranged at
or on the inner surface of the top wall 110 and/or bottom wall 115 of the pipe
segment 105. The water nozzle 130 may in a particular embodiment comprise an
elongate slit, for example provided in the top wall 100 and/or bottom wall 115
of
the pipe segment 105. The slit may, as schematically illustrated in figure 1,
be
arranged such that it extends along the top wall 110 or bottom wall 115 of the
pipe segment 105, for example in a direction perpendicular to the flow
direction
160 in the pipe segment. The slit may for example be a straight slit that
extends
along the entire width, or at least the 80 % of the width of the top wall 110
or
bottom wall 115 of the pipe segment 100. A water nozzle 130 may optionally be
arranged in or at the pipe segment top wall 110, and additionally be arranged
in
or at the pipe segment bottom wall 115. The delousing means 120 may thus
generally be arranged both in or on the pipe segment top wall 110 and in or on
the pipe segment bottom wall 115.
[0044] During a delousing operation, water containing a fish to be treated may
be
conducted through the pipe segment. The water nozzle or water nozzles may
then be used to inject water onto the fish to be treated such that a sea lice
present on the skin of the fish is removed. The shape of the pipe segment
described herein enables the water pressure from the nozzle(s) experienced by
each fish to be similar regardless of where in the cross section of the pipe
segment that the fish passes through. A delousing process performed in the
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module herein described may thus result in a higher consistency in sealice
removal from fish to fish relative to a delousing system of the same type
employing a circular pipe segment.
[0045] Figure 4 schematically illustrates an embodiment of the disclosure
where the
module 100 further comprises a water outlet 132 positioned upstream or
downstream from a water nozzle 130, and where the water outlet 132 is in fluid
communication with the nozzle 130. The water outlet 132 may here collect water
upstream or downstream of the water nozzle 130 that later injects the same
water onto fish being conducted through the pipe segment 105. An equilibrium
in
the rate of flow through the pipe segment 105 may thus be maintained, hence
reducing regions of low pressure in the pipe segment 105 where fish may be
stuck or hurt from irregular flows such as eddies. The fluid communication
between the water outlet 132 and the water nozzle 130 may be obtained using
suitable means such as a tube, built in tube, built-in channel, or similar.
Said
water outlet, or alternatively a separate water outlet may additionally or
optionally be employed in order to control the water flow velocity through the
pipe segment 105. Said water outlet 132, or alternatively a separate water
outlet
may according to a particular embodiment of the disclosure be configured to
adjust the velocity of water being conducted in the pipe segment 105 to a
velocity from 1.5 m/s to 2.5 m/s. The latter velocity has been found to be
optimal for maintaining the welfare of the fish, while at the same time
enabling
removal of sealice from the skin of the fish.
[0046] Figure 5 schematically illustrates a modular pipe system 200 for
delousing fish
where the modular pipe system comprises a module 100 for delousing fish. The
modular pipe system 200 is further illustrated as comprising a first coupling
unit
205 for connecting a first end of the module to a circular pipe, and a second
coupling unit 210 for connecting a second end of the module 100 to a circular
pipe. The first coupling unit 205 is here configured to connect a first end of
the
pipe segment 105 of the module 100 with a circular pipe, hence acting as a
transitional coupling for enabling fluid communication between the circular
pipe
and the pipe segment 105 of the module 100. The second coupling unit 210 is
similarly configured to connect a second end of the pipe segment 105 of the
module 100 with another circular pipe, hence acting as a transitional coupling
between the pipe segment 105 of the module 100 and the other circular pipe.
The module 100, the first coupling unit 205 and the second coupling unit 210
are
here connected in series, with the first coupling unit 205 and the second
coupling
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unit 210 at each end. The module 100, the first coupling unit 205 and the
second
coupling unit 210 hence constitutes a modular system 200 with a continuous
channel for conducting water and fish passing therethrough.
[0047] The modular pipe system 200 may as schematically illustrated in figure
5
comprise additional modules, i.e. auxiliary modules 225, for treatment or
handling of fish. Any auxiliary module 225 may for example be an imaging
module for imaging fish or be a water treatment module for cleaning or
exchanging water flowing through the system. The modular pipe system 200
establishes a fluid pathway through the entire system 200, i.e. from a
circular
pipe into the first coupling unit 205, through the modules 100,225 of the
modular
system 200, and out through the second coupling unit 210 into another circular
pipe. The modules 100,225 may generally be coupled together using suitable
means such as one or more flange couplings. Alternatively, the modules 100,225
may be connected together using a hydraulic connection. A hydraulic connection
may here be considered as a connection where hydraulic pressure is used to
hold
the modules 100,225 of the modular system 200 connected to one another. The
first coupling unit 205 and second coupling unit 210 may be connected to any
of
the modules 100,225 using the same connection means as those listed above.
[0048] Figure 5 schematically illustrates a modular pipe system 200 for
delousing fish
where the modular pipe system 200 further comprises an auxiliary module 225.
The auxiliary module 225, the module 100, the first coupling unit 205 and the
second coupling 210 unit are here connected in series, with the first coupling
unit
205 and the second coupling unit 210 positioned at each end. The module 100
and the auxiliary module 225 are in other words positioned between the first
coupling unit 205 and the second coupling unit 210. The auxiliary module 225
comprises an auxiliary module pipe segment 230 for conducting water containing
fish, where the auxiliary module pipe segment 230 comprises an auxiliary
module
pipe segment top wall 235 and an auxiliary module pipe segment bottom wall
240. The auxiliary module 225 may further comprise a water draining means 245
for extracting water from the auxiliary module pipe segment 230, and/or a
water
injection means 250 for injecting water into the auxiliary module pipe segment
230. The water draining means 245 may here be arranged in or at the auxiliary
module pipe segment top wall 235 and/or in or at the auxiliary module pipe
segment bottom wall 240. The water injection means 250 is/are arranged in or
at
the auxiliary module pipe segment top wall 235 and/or in or at the auxiliary
module pipe segment bottom wall 240. The auxiliary module pipe segment 230
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may here have an auxiliary module transverse cross section 227 having the same
shape as the transverse cross section 107 of the pipe segment 105 of the
module
100. The fact that the cross section 107 of the pipe segment 105 of the module
100 matches the auxiliary module transverse cross section 227 of the auxiliary
module 225 means that a continuous fluid flow may be obtained going from the
pipe segment 105 of the module 100 into the auxiliary module pipe segment 230
of the auxiliary module 225 without experiencing significant disturbances at
the
interface between the two modules 100,225.
[0049] The water draining means and/or water injection means may according to
any
embodiment of the disclosure be configured to adjust the velocity of water
being
conducted in the auxiliary module pipe segment to a velocity in the range from
1.5 m/s to 2.5 m/s. The auxiliary module may be positioned upstream from the
delousing module in the delousing system in order to adjust the water velocity
in
the downstream delousing module pipe segment to a velocity measuring in the
range from 1.5 m/s to 2.5 m/s. The latter velocity has been found to be
optimal
for maintaining the welfare of the fish, while at the same time enabling
removal
of sea lice from the skin of the fish.
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