Abstract:
A method of preparing shrimps includes boiling them at a pressure exceeding atmospheric pressure, at a temperature exceeding the boiling temperature of water at atmospheric pressure, for keeping the meat of the shrimps in a compressed state while causing the meat to solidify and loosen from the shells of the shrimps. The shrimps are then rapidly cooled for causing the meat to be separated from the shells in an area behind the head of the shrimp and above the tail. Subsequently, the shrimps are peeled by mechanically opening the shells for allowing the meat contained within the shells to fall out. The meat is separated from the remains of the shrimps, including shell parts and eggs, by introducing the meat and remains into a separation liquid, causing the meat to float on the separation liquid while allowing the remains to sink. Finally, the meat is removed from the separation liquid.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Not Applicable 
     FEDERALL SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a technique for preparing shrimps, and more specifically, a method of boiling and peeling shrimps and of separating the meat of the shrimps from the remains of the shrimps which remains include shell parts and eggs. 
     The preparation of shrimps such as shrimps from cold water or from hot water i.e. shrimps from the arctic ocean or alternatively the oceans in areas with a tropical, a subtropical or a temperate climate, are conventionally prepared by boiling the shrimps and separating the boiled meat from the shell part of the shrimps and optionally from any eggs carried by the living shrimps. 
     Originally, the technique of preparing shrimps was carried out as a manual process involving boiling the shrimps in a container including boiling water and a manual peeling and separation of the meat from the shrimps. Within the last decades, several attempts have been made at automating these previous manual processes and of providing machinery for carrying out the peeling and separation processes. Although these technical solutions have, to some extent, been acceptable and also, to some extent, commercially successful, problems still exist as to the yield of meat produced in an automated and mechanical system for peeling and separating meat from the shell parts and the eggs after the shrimps have been boiled and also as to the quality of the product. It is a requirement in relation to the peeling and separation of meat from shells of shrimps that the meat should not to any substantial extent include remains from the shells or any eggs, as the presence of shell parts or eggs in the final product deteriorates the quality. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a reliable, fast and efficient technique of boiling, peeling and rinsing shrimps, in particular of providing rinsed shrimp meat from the boiled shrimps, allowing an easy separation of the meat from the shell parts and also ensuring a complete separation of eggs from the meat. 
     It is a further object of the present invention to provide a novel technique allowing the obtaining of an improved yield up to 5% more than the presently obtainable yield in terms of the weight percentage of meat obtained from the shrimps, thereby providing a more complete utilization of the raw material, being the shrimps to be boiled, peeled and separated into shrimp meat and remains, including shrimp shell parts and eggs. 
     It is a still further object of the present invention to provide a novel technique of boiling, peeling and separating shrimps into shrimp meat and remains including shrimp shell parts and shrimp eggs, which technique provides a reduced energy consumption as compared to the prior art automated and mechanical boiling, peeling and separation processes and techniques, providing a reduction of the energy consumption on the order of 25% or more. 
     The above objects together with numerous other objects, advantages and features, which will be evident from the detailed description below of preferred and advantageous embodiments of the technique according to the present invention, are in accordance with a first aspect of the present invention obtained by a method of preparing shrimps comprising:
         a) steam boiling the shrimps at a high pressure exceeding the atmospheric pressure, and at an elevated temperature exceeding the boiling temperature of water at the atmospheric pressure for a specific period of time for keeping the meat of the shrimps in a compressed state due to the pressurization, while rapidly heating the shrimps to the elevated temperature for causing the meat of the shrimps to solidify and to loosen from the shells of the shrimps;   b) rapidly cooling the shrimps to a temperature at or below the atmospheric temperature for causing substantially all meat of the shrimps to be separated from the shells of the shrimps between an area behind the head of the individual shrimp and a part above the tail of the individual shrimp;   c) peeling the shrimps by mechanically opening the shells of the shrimps for allowing the meat loosely contained within the shells of the shrimps to fall out from the shells of the shrimps;   d) separating the meat of the shrimps from the remains of the shrimps, including the shell parts and any eggs, by flotational separation of the meat from the remains, by introducing the meat and the remains into a separation liquid such as a brine solution, including a specific amount of NaCl by weight for causing the meat to float on the separation liquid while allowing the remains of the shrimps, including the shell parts and any eggs to sink; and   e) removing the meat from the separation liquid.       

     The method according to the present invention is characterized by two main features, namely on the one hand the steam boiling combined with the rapid cooling and the flotation separation. According to the steam boiling and rapid cooling feature, it has been realized that the steam boiling of the shrimps allows on the one hand a highly efficient and low energy-consuming boiling and on the other hand contributes to an easier peeling and separation of the meat from the remains of the shrimps. It is contemplated that the high pressure steam boiling provides a slight compacting of the meat during the boiling process, thereby providing a loosening of the meat from the surrounding shell, which loosening of the meat from the shell is further accelerated through the high temperature of the steam causing a high temperature increase, generating, due to the differences in heat expansion coefficients of the shell and the meat, a delimitation of the meat from the shell. 
     The loosening of the meat from the shell is further promoted through the rapid cooling as the steam-boiled shrimps, having a temperature of 150° C. or more from the highly pressurized steam boiling process, are rapidly cooled to a temperature below the atmospheric temperature, such as a temperature of 3° C.-5° C., which rapid cooling causes a contraction of the shrimp meat and also of the shell, thereby promoting the loosening and separation of the meat from the shell circumferentially encircling the meat. 
     The loosening or separation of the meat from the circumferentially encircling shells of the boiled shrimps makes the peeling of the shrimps easier, allowing the usage of simple peeling techniques such as mechanical compression of the shells for simply causing the shells to crack and allowing the previously boiled and rapidly cooled meat to be easily removed from the interior of the cracked shells by simply allowing the meat to fall out from the cracked or opened shells. 
     According to the second main feature of the technique according to the present invention, the separation of the meat from the remains of the boiled shrimps, including the shell or shell parts and any eggs, is accomplished in a flotation separation process, as it has surprisingly been realized that a flotation separation process, provided that a specific separation liquid is chosen having a specific density, allows the meat to be floating on the separation liquid, whereas the remains of the shrimps, including the shrimp shells and any eggs, are allowed to sink. Thus, it has been realized that the eggs which are carried by the living shrimps during those periods of time when the shrimps are most tasty due to the presence of enough food, may also be separated from the meat, as the eggs have a slightly higher density as compared to the boiled meat of the shrimps. It is contemplated that numerous biologically acceptable separation liquids may be used; however, according to the presently preferred embodiment, brine is used having a content of NaCl of the order of 6-14%, preferably 9.5% by weight, which separation liquid is biologically acceptable for the reason that the shrimp meat, after the completion of the boiling, cooling, the peeling and separation processes is usually salted for improving the taste of the shrimp meat. Therefore, the use of the brine solution for the flotation separation process gives no after-taste to the shrimp meat, nor does it deteriorate the taste of the shrimp meat. 
     As described above, the pressure of the steam boiling process has to exceed the atmospheric pressure for providing the loosening of the meat from the circumferentially encircling shell. Therefore, the pressure in step b) is preferably of the order of 4-20 bar, e.g. 6-16 bar, preferably 8-14 bar, further preferably approximately 12 bar, or of the order of 4-6 bar, 6-8 bar, 8-10 bar, 10-12 bar, 12-14 bar, 14-16 bar, 16-18 bar or 18-20 bar. 
     Similarly, the steam boiling temperature should, as discussed above, provide the separation of the meat from the shell, and therefore, the temperature in step a) is preferably of the order of 150° C.-250° C., such as 160° C.-210° C., preferably 180° C.-200° C. further preferably approximately 190° C., or 150° C.-170° C., 170° C.-190° C., 210° C.-230° C. or 230° C.-250° C. 
     According to the advantageous effect of providing a shrimp boiling process that saves energy as compared to a conventional boiling process, the steam boiling process is carried out within a very short period of time such, as a time of less than 20 sec., such as 1-15 sec., preferably 2-10 sec., further preferably 4-6 sec., or 1-2 sec., 2-3 sec., 3-4 sec., 4-5 sec., 5-6 sec., 6-8 sec., 8-10 sec., 10-12 sec., 12-14 sec., 14-16 sec. or 16-20 sec. 
     The loosening of the meat from the circumferentially encircling shells of the shrimps is, as discussed above, further promoted through the rapid cooling of the shrimps from the high boiling temperature, preferably being higher than 150° C., to a low temperature, such as a temperature of approximately 0° C.-20° C., e.g. 2° C.-10° C., preferably 5° C.-8° C., or 1° C.-3° C., 3° C.-5° C., 5° C.-7° C., 7° C.-10° C., 10° C.-15° C., 15° C.-20° C. 
     It is to be realized that the combined method according to the present invention, including the steps a)-e), may be carried out as a continuous process or alternatively as a batch or intermittent process, or it may alternatively be combined as one or more of the steps performed as batch process steps whereas the remaining steps may be carried out as continuous process steps. In particular, the boiling may be performed in a pressurised boiler in a continuous operation as the shrimps are continuously introduced into the steam boiler, and after the above short period of time removed as a continuous flow of boiled shrimps from the steam container and introduced to the rapid cooling step. Alternatively and presently preferred, the boiling is performed in a set of pressurized boilers as a semi-continuous process involving the intermittent and sequential operation of the steam boilers of the set of boilers. In particular, according to the presently preferred embodiment of the method according to the present invention, the boiling is performed in a pressurized boiler in an intermittent batch operation. 
     As already discussed above, the rapid cooling of the high temperature steam-boiled shrimps is preferably performed by simply sinking the boiled shrimps into a cooling bath having the above discussed temperature below the atmospheric temperature. 
     For improving the separation of the meat from the remains of the shrimps, including the shell parts and any eggs, the method preferably further includes a step prior to step d) of forcedly introducing the peeled shrimps into the separation liquid or alternatively stirring the peeled shrimps in the separation liquid for causing a physical separation of the meat from the remains of the shrimps, including the shell parts and any eggs, for preventing meat from sticking between shell parts or being concealed within eggs due to a compacting of the material, including the meat, the shell parts and any eggs being prevented from being rinsed before the completion of the flotation separation step. 
     It is to be realized that the present invention according to further aspects includes the separate steps a) in combination with steps b) (peeling) and d) (separating) of the method according to the first aspect of the present invention. 
     Consequently, according to a further aspect of the present invention, a method of boiling shrimps is provided comprising:
         a) steam boiling the shrimps at a high pressure exceeding the atmospheric pressure, and at an elevated temperature exceeding the boiling temperature of water at the atmospheric pressure for a specific period of time for keeping the meat of the shrimps in a compressed state due to the pressurization, while rapidly heating the shrimps to the elevated temperature for causing the meat of the shrimps to solidify and to loosen from the shells of the shrimps, and   b) rapidly cooling the shrimps to a temperature to or below the atmospheric temperature for causing substantially all meat of the shrimps to be separated from the shells of the shrimps between an area behind the head of the individual shrimp and a part above the tail of the individual shrimp.       

     According to a further aspect of the present invention, a method of separating meat from the remains of boiled shrimps, which remains include shell parts and any eggs, which method comprises:
         separating the meat of the shrimps from the remains of the shrimps, including the shell parts and any eggs, by flotational separation of the meat from the remains by introducing the meat and the remains into a separation liquid such as a brine solution, including a specific amount of NaCl by weight for causing the meat to float on the separation liquid while allowing the remains of the shrimps, including the shell parts and any eggs, to sink.       

     The above objects together with numerous other objects, advantages and features which will be evident from the below-detailed description of preferred and advantageous embodiments of the technique according to the present invention are in accordance with a further aspect of the present invention obtained by a plant for preparing shrimps, comprising:
         a) a boiler section for steam-boiling the shrimps at a high pressure exceeding the atmospheric pressure, and at an elevated temperature exceeding the boiling temperature of water at the atmospheric pressure for a specific period of time for keeping the meat of the shrimps in a compressed state due to the pressurization while rapidly heating the shrimps to the elevated temperature for causing the meat of the shrimps to solidify and to loosen from the shells of the shrimps;   b) a cooling section for rapidly cooling the shrimps to a temperature at or below the atmospheric temperature for causing substantially all meat of the shrimps to be separated from the shells of the shrimps between an area behind the head of the individual shrimp and a part above the tail of the individual shrimp;   c) a peeling section for peeling the shrimps by mechanically opening the shells of the shrimps for allowing the meat loosely contained within the shells of the shrimps to fall out from the shells of the shrimps;   d) a flotation separation section for separating the meat of the shrimps from the remains of the shrimps, including the shell parts and any eggs, by flotational separation of the meat from the remains by introducing the meat and the remains into a separation liquid such as a brine solution, including a specific amount of NaCl by weight for causing the meat to float on the separation liquid while allowing the remains of the shrimps, including the shell parts and any eggs, to sink; and   e) a transfer section for removing the meat from the separation liquid.       

     The plant according to the present invention preferably includes any of the features discussed above with reference to the above described method according to the first aspect of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is now to be further described with reference to the drawings in which: 
         FIG. 1  is an overall diagrammatic, perspective and schematic view of a first and presently preferred embodiment of a plant, according to the present invention, for carrying out the method according to the present invention of boiling and rinsing shrimps, comprising three main sections: a boiler section, a peeling section and a rinsing and separation section; 
         FIG. 2  is a vertical sectional view of the rinsing and separation section shown in  FIG. 1 ; 
         FIG. 3  is an elevational end view of an alternative embodiment of the rinsing and separation section shown in  FIGS. 1 and 2 ; 
         FIG. 4  is a perspective, schematic and partly broken away view of an alternative embodiment of the rinsing and separation section shown in  FIGS. 1-3 ; 
         FIG. 5  is a perspective and schematic view of a modified embodiment of the boiler section shown in  FIG. 1 , including a transfer section for the transfer of boiled shrimps from the boiler section to the peeling section; 
         FIG. 6  is a schematic and sectional view of a boiler of the batch steam boiler section shown in  FIG. 1 ; 
         FIG. 7  is a schematic and perspective view of a shrimp illustrating those areas at which the peeling process is preferably initiated; and 
         FIG. 8  is a perspective, schematic and partly broken away view illustrating in greater details the peeling section of the plant shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1 , a first and presently preferred embodiment of a plant according to the present invention for boiling, peeling, rinsing and separating shrimps according to the method of the present invention is shown, composed of a plurality of sections. 
     The plant is in its entirety designated by the reference numeral  10  and comprises a two-part batch boiler section  12 , a peeling section  14 , a rinsing and separation section  16  and finally the transfer section  18 . 
     The individual sections  12 ,  14 ,  16  and  18  are to be described in greater detail below. At this point, however, an overall description of the plant  10  and the sections thereof is presented. In the steam boiler section  12 , two steam boilers are operated intermittently for providing a substantially continuous output of boiled and rapidly cooled shrimps to the peeling section  14 . In the peeling section, the boiled and cooled shrimps are peeled by breaking the shells of the shrimps for allowing the meat of the shrimps to be separated from the shells of the shrimps. In the rinsing and separation section, the meat of the shrimps is rinsed and the remains, i.e. the shrimps&#39; shells and also the eggs of the shrimps, are separated from the meat. Finally in the transfer section, the peeled and rinsed shrimps are transferred to a further processing section, such as a packaging and freezing section, which section is not part of the present invention. 
     Now turning to the individual sections, the boiler section having two intermittently operated steam boilers is first to be described. One boiler is designated by the reference numeral  20 , and the other boiler is designated by the reference numeral  22 . The boilers receive high temperature and high pressure steam such as 12 bar, 190° C. steam from a steam supply tube  24  as the steam is input to the one boiler  20  through a closure valve  26  and similarly, the steam input to the second boiler  22  is input through a closure valve  28 . The closure valves  26  and  28  are mounted on steam inlet tubes  30  and  32 , respectively. The boilers  20  and  22  and vented through venting tubes  34  and  36 , respectively, as the venting of the boiler chambers within the boilers  20  and  22  is controlled by means of additional closure valves  38  and  40 , respectively. Each of the boilers  20  and  22  has a high pressure enclosure  42  and  44 , respectively, having a bottom outlet  46  and  48 , respectively. At the opposite upper ends of the boilers  20  and  22 , two closure caps  50  and  52 , respectively, are provided, constituting openable caps or lids through which a container including a specific amount of shrimps, such as a batch of 5-25 kg is introduced into the interior of the enclosures  42  and  44 , respectively. 
     The bottom outlets  46  and  48  communicate with upwardly open cooling containers  54  and  56 , respectively, containing cooling water as indicated by the reference numerals  58  and  60 , respectively. The cooling water is input to the cooling containers  54  and  56  by means of a water supply including a water supply tube  62  and a water supply reservoir  64  from which the cooling water is poured into the cooling containers  54  and  56 , respectively, through additional valves  66  and  68 , respectively. As is well known in the art, the containers  54  and  56  include thermostat elements for controlling the valves  66  and  68  as the valves  66  and  68  are opened for the entry of water, provided that the temperature of the cooling water  58  and  60  or one of the container  54  and  56  rises above a specific level necessitating the additional cooling by the supply of additional cooling water. 
     From the bottom of the enclosures  54  and  56  two outlet ducts  70  and  72 , respectively, extend for allowing the shrimps, which have been introduced into the water  58  and  60  of the cooling reservoirs  54  and  56 , respectively, to be output to the peeling section  14 . 
     In the high pressure and high temperature steam boiler described above and shown in  FIG. 1 , the process time for the boiling of one batch of shrimps by the supply of 12 bar, 190° C. steam is of the order of 4 sec., allowing one batch of shrimps to be boiled within a period of approximately 6-8 sec., including the time for the introduction of the batch into the boiler and the time for discharging the steam-boiled shrimps to the cooling containers  54  and  56 , respectively. 
     The steam-boiled and cooled shrimps delivered from the outlet ducts  70  and  72  are received in the peeling section  14 , including two parallel side bars  80  and  82  in which a plurality of parallel extending stainless rollers  84  are journalled and operated by means of a motor  86  causing the rollers  84  to rotate in opposite directions, as is illustrated in  FIG. 8 . In a specific embodiment, the rollers  84  have an outer diameter of approximately 30 mm, defining a spacing between any two adjacent rollers on the order of 1 mm, and are operated by the motor  86  to rotate at a speed of approximately 30 rpm. The rollers  84  cause the shrimps to be slightly compressed between the two oppositely rotating rollers, causing the shells of the shrimps to break as the shell of each individual shrimp has, due to the rapid boiling and rapid cooling, loosened its grip on the meat of the shrimp. 
     In  FIG. 7 , a shrimp  90  is shown having a head part  92 , a body part  94  and a tail  96 . The transition between the head part and the body part is indicated by an arrow  93  and similarly, an arrow  95  indicates the transition from the body part  94  to the tail  96 . Due to the rapid boiling and rapid cooling of the shrimps, the shells constitute fairly loose encasings relative to the meat of the individual shrimps. The shell of the shrimp breaks at the above transitions indicated by the arrows  93  and  95 , generally allowing an almost 100% utilization of the meat of the individual shrimp as compared to conventional techniques in which the shrimps are boiled at the atmospheric pressure and at a temperature of approximately 100° C. 
     In  FIG. 8 , a detail of the rollers  84  of the peeling section  14  is shown illustrating the peeling function of the rollers. The rollers  84  constitute revolving rollers, i.e. rollers which, in the orientation shown in  FIG. 1 , rotate for an extended period of time in the clockwise direction and which are periodically reversed for rotating synchronically in the counter-clockwise direction. The unpeeled shrimps are, in the clockwise direction performed by the rollers  84 , caused to be brought into the gap between any two adjacent rollers, causing a crushing of the shrimps and slightly compress the boiled shrimps, thereby causing the shells to be separated from the meat. The distance between the rollers prevents the meat from falling between the rollers, whereas the shells, the shell parts, and the eggs separated from the meat of the shrimps fall between the rollers  84  onto the conveyor belt shown in  FIG. 1 , from which conveyor belt the separated shell parts and any eggs attached to the shell parts are disposed. The shrimp meat, and shrimp meat having attached shell parts, and any eggs attached to the shell parts are carried along by the rollers  84  and delivered from the peeling section  14  to the rinsing and separation section  16 . It is to be realized that the material delivered from the peeling section  14  to the separation section  16  includes any remaining shell parts having eggs attached thereto and loose meat and further shrimp meat having shell parts attached thereto. The rinsing and separation section  16  is physically mounted below the conveyor belt  88 ; however, in  FIG. 1 , as indicated by an arrow  98 , the rinsing and separation section  16  is, for illustrative purposes, positioned above the conveyor belt  88 . 
     In the rinsing and separation section  16 , the shrimp meat is rinsed from any shell parts or eggs adhering to the meat and further separated from the shells and the eggs. The material, including the shrimp meat, the shell or shell parts, and the shrimp eggs, is delivered from the output end of the conveyor belt  88  to a set of rotating agitators  100  which are journalled in two parallel side bars, one of which is shown in  FIG. 1  and designated the reference numeral  102 , and which are rotated in opposite directions by means of a motor  104 . Basically, the agitators  100  are operated similar to the rollers  84  of the peeling section  14 ; however, the agitators  100  are positioned in spaced apart relationship allowing the material after the mechanical agitation to be delivered into a separation bath of a separation container  106 . The container  106  is composed of two opposite side walls  108  and  110 , a front wall  112  and an end wall  114 . The container also has a bottom wall  116  in which an outlet funnel  118  is provided, which funnel communicates with a bottom pump assembly  120  from which the shell parts and the shrimp eggs are delivered to an outlet tube  122 . Between the two side walls  108  and  110 , a chute wall  124  extends from below two downwardly protruding V-defining walls  126  and  128  to the funnel  118  for guiding the shell parts and the shrimp eggs to the bottom outlet funnel  118 . 
     Within the separation container  106 , brine  130  is contained, including approximately 9.5% NaCl by weight for providing a flotation separation of the shrimp meat from the remains of the shrimps, including the shell parts and the shrimp eggs. It has surprisingly been realized that a specific separation threshold exists, allowing the shrimp meat to be separated from the remains of the shrimps, namely the shrimp shells and the shrimp eggs. The brine is input to the separation container through two brine inlet tubes  132  and  134 , and the brine is allowed to float out from the separation chamber  106  at an outlet opening in the rear wall  114  as the brine carrying the shrimp meat is allowed to fall down into the transportation section  18 . 
     In  FIG. 2 , a vertical sectional view of the separation container  106  is shown, in which the shrimps, including the shrimp meat, the shrimp shells, and the shrimp eggs, are introduced into the separation container through a delivery funnel  136  rather than by means of the agitators  100  shown in  FIG. 1 . 
     As the brine is introduced through the tube  132 , the water is forced upwardly along a vertical wall part of the chute wall  124  carrying along the material input through the funnel  136  and including the shrimp meat, the shrimp eggs, and the shrimp shells. The material carried along with the brine is forced downwardly below the two V-defining walls  126  and  128  providing a steering effect for separating the constituents from one another and allowing the rinsed and cleaned shrimp meat parts  138  to float on top of the brine, whereas the shell parts  140  and the eggs  142  sink to the bottom of the separation container  106 , allowing the shrimp shell parts  140  and the shrimp eggs  142  to deposit in the outlet funnel  118  of the separation container, from which outlet funnel (shown in  FIG. 1 ), the waste material, i.e. the shrimp shell parts  140  and the shrimp eggs  142 , is output through the outlet  122  shown in  FIG. 1 . 
     After the flotation separation process has been completed, the brine carrying the shrimp meat parts  138  is output from the rear end of the separation container, i.e. opposite to the inlet end at which the brine inlet  132  and the funnel  136  are positioned, and transferred to the transport section  18 . 
     In the transport section  18  shown in  FIG. 1 , a conveyor belt  144 , which constitutes a filtering conveyor belt, carries the shrimp meat parts to the packaging and freezing section (not shown in the drawings), whereas the brine is expelled to a bottom funnel  146 , from which the brine may be discarded, or alternatively, as shown in  FIG. 2 , recirculated to the inlet end of the separation container by means of a pump  148  delivering the recirculating brine to the inlet end of the separation container  106 . 
     The technique of removing the waste, i.e. the shell parts  140  and the eggs  142 , from the flotation separation container  106  may be accomplished in numerous ways as an intermittent operation or a continuous operation. 
     In  FIG. 3 , a modified embodiment of the separation container is shown, differing from the above described first and presently preferred embodiment shown in  FIGS. 1 and 2 , in that the side walls  108  and  110  constituting vertical side walls in  FIG. 1  are substituted by sloping side walls  108 ′ and  110 ′. In a transverse direction relative to the separation container  106 , a belt  144  extends, which belt is driven by a motor  145 . The belt is forced down into contact with the inner surface of the separation container  106  by means of two pressure arms  148  and  150  carrying pressure rollers  152  and  154 , respectively. As the pressure rollers are in their lowermost operational position shown in solid outline in  FIG. 3 , the bottom part of the belt  144  is raised, as illustrated in solid outline in  FIG. 3 . The belt  144  passes around a drive roller  156  connected to the drive motor  145  and around an idler roller  158  positioned symmetrically relative to the drive roller  156 , as the drive roller  156  is positioned above the sloping side wall  110 ′, whereas the idler roller  158  is positioned above the sloping side wall  108 ′. 
     The bottom part of the belt  144  is guided around two rollers  160  and  162  which are interconnected by means of a spacing bar  164 . Below the lower part of the belt contacting the rollers  160  and  162 , a sloping rinsing wall  170  is positioned, which rinsing wall  170  is fixed to supporting legs  172  and  174  of the rinsing and separation section  16 . 
     As shrimp shells and shrimp eggs are collected on the part of the belt  144  positioned between the two pressure rollers  152  and  154 , and while the flotation separation process is performed, the collected quantity of shrimp shells and shrimp eggs needs, after a period of time, to be removed. The removal of the shrimp shells and shrimp eggs in the modified embodiment shown in  FIG. 3  is accomplished by simply raising the pressure arms  148  and  150  from the solid outline positions shown in  FIG. 3  to the dotted outline positions, allowing the belt  144  to be raised, and by operation of the motor  145  driving the belt by means of the drive pulley  156 , the waste material is carried by the belt around the roller  158  and is delivered to an outlet passage connected to the separation wall  170  against which the belt is pressed for mechanically rinsing the belt as the lower part of the belt  144  is lowered into contact with the sloping rinsing wall  170  as the bar  164  swings downwardly, as is illustrated in dotted outline in  FIG. 3 . 
     In  FIG. 4 , a further modified embodiment of the separation container  106  is shown in which a transverse conveyor is used for the removal of shrimp shells and shrimp eggs from the bottom of the separation container  106 . In  FIG. 4 , two guide rails  180  and  182  are provided in which a transverse conveyor belt  184  is guided transversely relative to the longitudinal direction of transportation of brine through the separation container  106 . The conveyor belt  184  is provided with outwardly protruding carrier plates  186  by means of which the shrimp shells and shrimp eggs are lifted along the side wall  108  of the separation container  106  as the conveyor belt  184  is moved in the direction indicated by two arrows  188  and  190  in  FIG. 4 . The conveyor belt  184  is guided through the guide rails  180  and  182  and further around two top rollers  192  and  194  and further around a drive roller  196  powered by a motor  198  and around a bottom idler roller  200 . Between the top rollers  192  and the drive roller  196 , the conveyor belt  184  defines a sloping surface from which the shrimp shells and the shrimp eggs carried by the conveyor belt are thrown into a waste container  202 . 
     Apart from the above described techniques of removing the waste material, i.e. the shrimp shells and the shrimp eggs, from the separation container  106  by means of a bottom funnel, a transverse, periodically-operated belt and a continuous operated belt having carried plates, numerous other removal techniques are obvious to a person having ordinary skill in the art and are contemplated to be part of the present invention as defined in the appending claims. 
     In  FIG. 5 , a modified cooling enclosure  54 ′ is shown in which a sloping conveyor is used for the removal of the steam-boiled and rapidly cooled shrimps from the cooling water  58 ′, which conveyor belt is designated the reference numeral  208  and is passed around a drive roller  210  powered by a motor  212  and a total of three idler rollers  214 ,  216 , and  218  as the belt is moved in the direction indicated by an arrow  220  for the transfer of the steam-boiled and rapidly cooled shrimps to the peeling section  14  positioned below the drive roller  210  of the conveyor assembly including the conveyor belt  208 . 
     Rather than a cooling water supply tube, as illustrated in  FIG. 1 , the cooling enclosure  54 ′ shown in  FIG. 5  is provided with a recirculation circuit in which a cooling apparatus  230  is included having an internal pump  232  for the circulation of the cooling water through the cooling apparatus  230  and for the delivery of the cooling water to the cooling enclosure  54 ′. The cooling of the water is accomplished by means of a conventional cooling compressor circuit having a cooling compressor, an evaporator, etc. as is well known in the art per se. 
     In  FIG. 6 , one of the two batch steam boilers  20  and  22  is shown in schematic view, illustrating the interior of the boiler in which the shrimp batch is included in a container  21  which is heated by means of steam input through the closure valve  26  as the batch container  21  is introduced into the interior of the enclosure  42  by opening a cap  50  by means of a thumb wheel  51 . From the bottom outlet  46 , the batch container  21  is delivered to the cooling water  54  by the opening of the bottom outlet by means of a thumb wheel  47 . 
     Although the technique of steam boiling shrimps and rapidly cooling the shrimps for the loosening of the shrimp shell from the shrimp meat, the peeling of the shrimps by means of solid stainless steel rollers and finally the flotation separation technique according to the present invention has been described with reference to specific and presently preferred embodiments, the present invention is by no means limited to the above described embodiments, techniques or alternatives, as numerous modifications and alterations are to be considered obvious to a person having ordinary skill in the art without deviating from the true spirit and scope of the invention as defined in the appending claims.