Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR CONTROLLING MECHANICAL PROCESSING
HEADLESS AND GUTTED WHITEFISH AND DEVICE
FOR CARRYING OUT SAID METHOD
The invention relates to a process for controlled machine processing of
headless and
gutted white fish, in particular for producing salt fish, wherein the inain
bone is
separated out in the region of the abdominal cavity. The invention also
relates to a
device suitable for carrying out the process. Cod, pollack, cusk and ling may
be
mentioned as examples of white fish to be processed.
When separating out the main bone in the region of the abdoniinal cavity, some
of the
neck blood and some of the blood sac remains at the tail-side end of the
abdominal
cavity in the product. These blood residues are traditionally removed
manually, after
the white fish product has been taken from the fish-processing machine. The
required
working steps are expensive in terms of time and personnel. Conventional
manual
brush cleaning must proceed relatively intensively, namely deep-acting, over a
large
surface area and also for a long time on open flesh. There is thus the danger
of
contamination by bacteria being distributed over a wide surface of the flesh.
The aims of the invention are to simplify the said processing of white fish
with
respect to the removal of blood residues. Cleaning should take place largely
by
machine and in a manner which protects the product and should eliminate the
danger
of contamination existing in traditional manual brush cleaning. A device
suitable for
carrying out the process should be siinple to construct and be able to be
operated for
white fish which are very different in length and weight at optimum throughput
rate.
According to the present invention, there is provided a process for controlled
machine processing of headless and gutted white fish having a body with a main
bone, wherein the main bone is separated out in a region of an abdominal
cavity
of the fish, characterised in that neck blood residues exposed on a head side
of
cut lateral blood kidneys of the body of the fish to be processed and
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provided with the main bone are removed using at least one cleaning high-
pressure liquid jet aligned with the neck blood residues, such that flesh of
the
fish remains protected from the high-pressure liquid jet by a membrane of the
fish, spanning the main bone on an abdomen side of the fish, and in that the
main bone lying in the region of the abdominal cavity is then removed and
hence
the fish membrane is opened, as a result of which neck blood residues of the
lateral blood kidneys cut at the head of the fish and lying on a tail side of
the fish
become free.
Preferably, the aims are achieved in the process mentioned in the introduction
in
that neck blood residues exposed on the head-side, with which the fish to be
processed is tainted, are removed before separating out the main bone using at
least one cleaning high-pressure liquid jet aligned with the neck blood
residues.
In a device suitable for carrying out the process, which comprises a conveying
device determining the conveying path for conveying the fish to be processed
in
plural and a filleting device arranged on the
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conveying path for separating out the main bone in the region of the abdominal
cavity, according to the invention a high-pressure liquid jet cleaning device
for
removing head-side neck blood residues is arranged along the conveying path in
the
direction of fish travel upstream of the filleting device. One important
measure
according to the invention consists in at least removing a large part of neck
blood
residues by means of at least one high-pressure liquid jet automatically in a
fish
machine and largely in a manner which protects the product. This is possible
in that
neck blood exposed in depressions and occurring on the fish membrane is
removed
using liquid blasting under high pressure, advantageously and expediently
using
water, wherein the flesh remains protected by the fish membrane over the
abdominal
cavity. The liquid high-pressure cleaning of the invention takes place in a
relatively
short time, locally concentrated and limited. Consequently, due to the measure
that
high-pressure liquid jet cleaning is carried out before separating out the
main bone
lying in the abdominal cavity region, on the one hand exposed blood residues
are
removed virtually without residue using liquid means, which is applied
intensively at
a local defined site, and on the other hand the fish flesh remains uninjured
in spite of
this intensive machine cleaning. Due to the removal according to the invention
of
neck blood residues exposed on the head side, a considerable saving of
personnel and
costs is achieved by avoiding expensive brush cleaning to be carried out
traditionally
by hand. The high-pressure liquid jet cleaning device of the invention can be
operated
not only using high speed, but it is also constructed simply and in space-
saving
manner. On the whole, considerable advantages are thus achieved for processing
headless and gutted white fish, the main bone of which can be removed only in
the
abdominal cavity region.
Advantageously, first of all the fish to be processed may be sliced in the
tail region
laterally of the main bone, before the exposed neck blood residues are removed
directly thereafter by means of high-pressure liquid jet cleaning.
A very particularly advantageous measure of the invention consists in that
after
separating out the main bone, neck blood residues lying on the tail side are
removed
using means which protect the flesh. It is post-cleaning, since according to
the
invention the greatest part of neck blood residues has already been removed by
the
step of high-pressure liquid jet cleaning. It has been found that after
separating out the
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main bone lying in the region of the abdominal cavity, that is after opening
the fish
membrane, only a relatively small part of the neck blood, namely about 20 %
and less,
remains on the then open fish flesh. Such residues may advantageously be
detached
using brush means which particularly protect the flesh, the intensity of which
is
largely reduced.
A supplementary further process step may advantageously consist in that after
the fish
to be processed has been sliced in the tail region laterally of the main bone,
a blood
sac residue lying at the tail-side end of the abdominal cavity is removed
using at least
one cleaning high-pressure liquid jet aligned with the latter. First of all
the main bone
may advantageously be separated out in the region of the abdominal cavity and
the
blood sac residue may be removed after removing neck blood.
At least one cleaning high-pressure liquid jet in the form of a high-pressure
waterjet,
advantageously having jet pressure at the blood site to be removed of at least
50 bar,
preferably at 70 to 100 bar, may advantageously be applied at a blood site to
be
cleaned primarily.
In order to control the cleaning operation, the process of slicing the fish in
the tail
region laterally of the main bone may be used particularly advantageously,
wherein a
fish size value is obtained for controlled operation of at least one cleaning
step.
In order to render neck blood residues to be removed accessible as much as
possible
to high-pressure liquid jet cleaning, the fish is advantageously conveyed in a
position
pressed against lateral support at least at one site upstream of jet cleaning
in order to
press forward neck blood residues below the fish membrane.
A further advantageous additional process measure may consist in that the
region of
the processed fish which is freed of blood residues is washed using rinsing
liquid,
which is applied at low static pressure in a manner which protects the flesh.
The cleaning device may advantageously have at least one pair of nozzles
producing
in each case a high-pressure liquid jet for removing head-side neck blood
residues,
wherein the nozzles are aligned assigned to depressions of a passing fish
having the
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blood and lying laterally of the main bone and on the head-side end of the
fish
membrane.
In order to slice the fish in the tail region before cleaning, a device for
slicing the
tail region of the fish laterally of its main bone is arranged along the
conveying
path in the direction of fish travel upstream of the cleaning device provided
for
removing head-side neck blood residues.
According to the present invention, there is also provided a device for
processing of headless and gutted white fish for carrying out the process,
comprising a conveying device determining a conveying path for conveying the
fish to be processed in plural and a filleting device arranged on a conveying
path
for separating out the main bone in the region of the abdominal cavity,
characterised in that a high-pressure liquid jet cleaning device for removing
neck
blood residues exposed on the head side of cut lateral blood kidneys of the
fish
body to be processed and provided with the main bone is along the conveying
path in the direction of fish travel upstream of the filleting device, so that
said at
least one cleaning high-pressure liquid jet blasted from the cleaning device
is
aligned with the exposed neck blood residues such that the fish flesh remains
protected from the high-pressure liquid jet by the fish membrane spanning the
main bone on the abdomen side.
Preferably, in order to also remove by machine proportionately fewer neck
blood
residues, which occur after filleting in the region of the fish abdominal
cavity, a
cleaning device for removing tail-side neck blood residues may be arranged
advantageously in the direction of fish travel downstream of the filleting
device.
Such a cleaning device advantageously has a detaching means having
mechanical detaching elements and which can be contacted with the blood sites
in a manner which protects the flesh. This means is advantageously formed by
at least one drivable brush, preferably in the form of a double cone-like
roller
brush which can be rotated. A controllable means, which brings the brush into
cleaning engagement with the blood sites to be cleaned when passing the
latter,
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may advantageously be assigned to the brush. In a preferred embodiment
according to the invention, a cover element, the position of which can be
changed accordingly, which releases the brush only for cleaning, otherwise
which covers it, is provided as a controllable engagement means. The brush
engagement means may advantageously have a movement means, by means
of which the brush can be moved in particular by adjustable compressive force
against the blood sites to be cleaned and can be removed from the latter. The
cleaning device provided for removing tail-side neck blood residues may also
advantageously comprise a controllable means for pressing the fish against the
detaching means in the region of the blood sites to be cleaned.
Preferably, in a development of the device of the invention, a high-pressure
liquid jet device for removing blood sac residue lying at the tail-side end of
the
abdominal cavity may be arranged on the conveying path. This cleaning device
is arranged expediently and advantageously along the conveying path in the
direction of fish travel behind the filleting device.
Preferably in order to arrange nozzles of a cleaning device of the invention
in a
particularly space-saving and simple manner, in an embodiment of the
invention,
at least one transfer body is provided with at least one opening for the
passage
of cleaning liquid, which is blasted from at least one nozzle, wherein the
transfer
body preferably has a support surface pointing upwards for abdomen-side fish
support.
Preferably, in order to treat sites already essentially freed of blood
residues for
removing cleaning residues, a further cleaning device in the form of a rinsing
device for washing the blood sites to be cleaned may be arranged in the
direction of fish travel behind at least one cleaning device primarily
removing
blood residues. The rinsing device preferably has at least one rinsing nozzle
releasing rinsing liquid, in particular water, under low static pressure.
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A device for slicing the tail region of the fish laterally of its main bone
may
advantageously be arranged along the conveying pat in the direction of fish
travel upstream of the cleaning device provided for removing head-side neck
blood residues, wherein a measuring device with assigned conveying path for
fish length measurement, which is provided for operational control at least of
a
cleaning means which removes blood residues, is arranged before the cutting
device.
Particularly expedient and advantageous embodiments or possibilities of the
invention are described in more detail using the following description of the
exemplary embodiments shown in the schematic drawing.
Figure 1 shows in longitudinal side view, a device of the invention with
cleaning
stations,
Figure 2 shows in detailed side view of the device according to Figure 1,
cutting
device assigned to the tail region of the fish and cleaning device arranged
downstream
of the latter,
Figures 3A and 3B show a headless and gutted white fish before processing in
bottom
view and sectional view,
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Figures 4A and 4B show in bottom view and sectional view, the fish according
to
Figure 3 after slicing in the tail region and having closed membrane in
position for
removing exposed head-side neck blood residues,
Figures 5A, 5B and 5C show in bottom, longitudinal and transverse view, the
fish
according to Figure 4 after filleting in the region of its abdominal cavity
and in
position of brush cleaning of the invention for removing tail-side neck blood
residues
and
Figure 6 shows in bottom view, the fish which is filleted in the abdominal
cavity
region and freed of neck blood residues with exposed blood sac residue in
position for
high-pressure liquid jet cleaning.
A device 9 of the invention provided for carrying out the process of the
invention, as
can be seen from Figure 1, comprises in a manner known per se, a frame 91
having a
cutting device 4 and filleting device 6 arranged downstream of the latter. A
table 92 is
provided, via which the device 9 is charged in succession with white fishes 1
to be
processed. A conveying device 3 comprises in serial arrangement, groups of
carrier
elements 311 guided in continuously circulating manner and driven by means of
conveying chain 31 for the transport of the fishes 1 in direction of fish
travel R along
the conveying path of the device 9. Each fish 1 is gripped by means of tail
clamps 312
and conveyed with its tail in front.
A first high-pressure liquid jet cleaning device 5 of the invention is
arranged along the
conveying path between the cutting device 4 and the filleting device 6. A
brush
cleaning device 7 of the invention is situated in the direction of fish travel
R behind
the filleting device 6. A rinsing device 99 is arranged downstream of this
brush
cleaning device 7, and a second high-pressure liquid jet cleaning device 8 of
the
invention follows the rinsing device 99 of the invention in turn in the
direction of fish
travel R.
As can be seen from Figures 1 and 2, conventional conducting bodies 93, 94,
via
which the fish 1 is brought to a cutting circular knife 41 of the cutting
device 4, are
provided at the entrance to the cutting device 4.
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Each white fish 1 to be processed is a fish body which is freed of head and
guts, but
still provided with main bone 11. This is shown in Figures 3A and 3B. As is
conventional for producing salt fish from white fish, the fish 1 is sliced in
the tail
region laterally of the main bone 11 from below to above the main bone 11 by
means
of the cutting device 4 and the knife 41 aligned accordingly vertically. The
cutting
line 411 can be seen from Figures 3A and 3B as a dot-and-dash line. The
product
shown in Figures 4A and 4B and guided over a conducting body 42 of the device
4 is
produced. This is tainted with blood residues 21 exposed towards the head end
of the
fish 1, which lie to the left and right laterally of the main bone 111 in
sites 2 formed
by depressions in the region of the collar bone 12. These blood sites 2 are
produced
when cutting lateral blood kidneys at the head of the fish.
Means may be provided in order to favour emergence of blood below the membrane
13. Advantageously, the conducting body 93 may be shaped at the start of the
conveying path by lateral flank surfaces 931 and/or may be provided with
projecting
elements so that lateral supports are formed, which act on the blood sites at
the outer-
lying abdomen flaps of the fish I under conveying pressure, in order to
additionally
press forward neck blood residues 21 below the fish membrane 13.
According to the invention, the neck blood residues 21 exposed on the head
side are
removed before separating out the main bone 111 lying in the region of the
abdominal
cavity 14 using high-pressure water jets 54 aligned with the neck blood
residues 21
(Figure 2). As can be seen from Figures 4A and 4B, the high-pressure water
jets 54
catch a working region 510 including the head-side neck blood residues 21.
Since the
main bone of the abdominal cavity region has not yet been separated out, the
fish
flesh remains protected from water jet cleaning by the fish membrane 13
spanning the
main bone 111 on the abdomen side.
Important parts of the first water jet cleaning device 5 can be seen in detail
from
Figure 2. The transfer body 42 has a roof ridge-like profile cross-section. An
opening
421, from which water blasts at high pressure, namely at advantageously 70 to
100
bar upwards into the working region 510, is situated in each lateral roof-
ridge surface
420. The openings 421 are produced by a pair of vertically directed openings
53 in the
conducting body 42. A pair of high-pressure water jet nozzles 51, which are
exposed
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to water in each case via a hose 52 and are aligned with the associated
opening 53, are
arranged below the body 42.
As can be seen in particular from Figure 2, the two water jets 54 produced on
the
roof-ridge surfaces 420 still lie in the region of the cutting knife 4, so
that cleaning
takes place briefly in time and in a short space and immediately following the
step in
the cutting device 4. In particular it may be advantageous to start high-
pressure water
jet cleaning even before the end of step 411. As is conventional in fish-
processing
devices and fish-processing machines, the units acting on the fish are
controlled as a
function of the length of the fish 1 conveyed into the device. For this
purpose, the
length of each fish 1 is measured. Length measurement advantageously takes
place in
a manner known per se in the region upstream of the cutting device 4. The
length
value used for cutting the fish 1 may then also be used advantageously for
controlling
the water jet nozzles 51. The water jets 54 are controlled in particular as a
function of
fish length via magnetic valves 55 by means of a conventional computer not
shown. It
is significant that the water jets are produced in a relatively short time and
with high
intensity when passing the sites 2 of blood residues 21.
According to the invention, the main bone 111 lyinR in the reizion of the
abdominal
cavity 14 is removed by means of the filleting device 6 only after cleaning in
the
device 5. The filleting device 6 comprises in a conventional arrangement and
design,
a pair of circular knives 61, which are indicated in Figure 4B by a dot-and-
dash line.
They are aligned at an angle with respect to one another according to the
flank bones
of the abdominal cavity 14. Whereas the part 112 of the main bone 11 remains
in the
tail region of the fish 1, the part 111 of the main bone 11 in the region of
the
abdominal cavity 14 is cut out of the fish 1 together with the membrane 13 and
the
blood kidneys lying below the main bone part 111. As can be seen from Figure
5A,
neck blood residues 22 of the lateral blood kidneys cut at the head of the
fish 1 and
lying at the sites 2 towards the end of the tail of the fish 1 thus become
free. These
blood residues 22 have a significantly lower proportion than the head-side
blood
residues 21 already removed, and they are now removed according to the
invention
using a cleaning means which protects the flesh. For this purpose, in the
exemplary
embodiment the brush cleaning device 7 is provided, which can be seen in more
detail
from Figure 5B and 5C with essential elements.
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The device 7 comprises a roller brush 71 which is like a double cone in
longitudinal
cross-section and which is mounted rotatably about an axis 710 in conjunction
with a
rotary drive 75. The axis 710 is directed vertically to an intended
synunetrical
conveying plane 90, in which the carriers 311 of the conveying device 3
circulate.
Bristles 76 terminate according to the obtuse-angle shape and guiding of the
fish 1 at
its bottom side using conically inclined brush detaching surface, so that they
pass in
adapted form in the working region 720 gently into brush engagement with the
tail-
side blood residues 22 lying at the sites 2, when the fish I passes the brush
71 for
cleaning.
The fish 1 is pulled through the device 7 with the tail end in front by means
of tail
clamps. The device 7 comprises a brush cover 72 which can be seen from Figure
5B
and which forms a controlled engagement means, and which has a shell segment
corresponding to the brush cone shape which can be pivoted back and forth
about the
roller axis 710 by means of control as a function of passing the blood
residues 22.
Figure 5B shows the cover 72 in the position releasing the bristles 76 for
cleaning the
blood sites 2. Outside of the cleaning phase, the cover 72 is pivoted below
the fish 1.
It forms a conducting surface, which closes a brush window 621 in a conducting
body
62, which takes the fish 1 from the filleting device 6.
As can be seen from Figure 1, the brush 71 is mounted pivotably and arranged
above
an arm about an axis 730 which is parallel to the roller axis 710 such that
the brush 71
can be pivoted towards the underside of the fish 1 or away therefrom, it can
thus be
raised and lowered in direction B. This movement for brush engagement is
controlled
in correspondence and connection with the movement of the cover 72, and
specifically as a function of the occurrence and the passing of the sites 2 to
be cleaned
of the blood residues 22. Pneumatic control means 73 and 78 are advantageously
provided, which are connected to conventional fish machine control.
As can be seen from Figures 1, 5B and 5C, the brush cleaning device 7 has
pressing
means in the form of suppressors 74 engaging laterally on the fish 1 in a pair
from the
top, and which are arranged to be pivotably movable about an axis 740 which is
parallel to the brush roller axis 710. The pivoting movement of these
suppressors 74 is
controlled in time with the fish-processing machine 9, and specifically such
that they
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prevent escape of the fish I at the top when the cover 72 is pivoted away and
the
brush 71 is raised.
As can be seen from Figure 1, the conducting body 42, which has the brush
window
621 which can be closed by the cover 72, has a water rinsing device 99
immediately
following the brush 71 spatially and in temporal operation. This water rinsing
device
99 is formed by a plurality of water nozzles 991 and openings 993, which are
provided and arranged in this respect in the same manner as the corresponding
elements of the cleaning device 5. However, an essential difference exists in
that the
nozzles 991 and the associated openings 993 are advantageously provided in
greater
number, for example four times, and the water jet force is only so great that
in the
working region 992 which can be seen from Figure 6, namely in the region of
the
blood sites 2 already cleaned using primary cleaning in the stations 5 and 7,
only final
cleaning rinsing takes place using low water pressure.
To realise a further process step of the invention, a second high-pressure
liquid jet
cleaning device 8, which is operated using water, is provided on the
conducting body
62 immediately spatially behind the rinsing device 99. This device has at
least one
nozzle 81 with assigned opening 83 arranged above the latter in the
conc_lucting hody
62. In the device 8, a controlled water jet under high pressure is aligned
with a further
blood site 2, at which namely a blood sac residue 23 lies at the tail-side end
of the
abdominal cavity 14, as can be seen from Figures 4A, 5A and 6. It is
significant that
this water jet high-pressure cleaning only takes place when the main bone 111
lying in
the region of the abdominal cavity 13 has been removed by means of the
filleting
device 6, since the blood sac freely comes to rest at the end of the then cut-
away
blood kidneys. In the exemplary embodiment, the blood sac residue 23 is
removed
after complete removal of neck blood. However, it may also be advantageous,
for
example to arrange the device 8 between the device 6 and the device 7. As for
the
other cleaning devices, water-jet control takes place, for example by means of
magnetic valve, as a function of the occurrence and passing of the blood sac
residue
23 at the cleaning device 8. For this purpose, the valve or valves are
connected to the
conventional operational control computer of a fish-processing machine for
water-jet
control.
