Abstract:
A rocker chiller includes a chilling tank and a baffle assembly. The baffle assembly includes a drive shaft, a baffle blade extending along a bottom of the tank and a plurality of spaced-apart and elongate baffle members extending in a radial direction from the drive shaft towards the bottom of the tank. The elongate baffle members contact the drive shaft at spaced-apart locations along the drive shaft and define a plurality of openings therebetween. The elongate baffle members are sized and shaped to push at least a majority of the carcasses laterally through the heat exchanging liquid in a direction generally orthogonal to a lengthwise forward movement of the carcasses from the first end of the tank to the second end of the tank.

Description:
REFERENCE TO PRIORITY APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 13/070,521, filed Mar. 24, 2011, now abandoned, which claims priority to U.S. Provisional Application Ser. No. 61/424,363, filed Dec. 17, 2010, the disclosures of which are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure generally relates to rocker chillers for carcasses such as poultry carcasses, that reduce the temperature and increase the moisture retention of the carcasses and that enhance the ability of the carcasses to more effectively respond to disinfectant. 
     BACKGROUND OF THE INVENTION 
     Paddle type chillers, also known as “rocker chillers,” have a history of use in the poultry processing industry and in other food processing industries. The basic principle of operation is that a paddle or long blade is used to agitate poultry carcasses in a tank of cold heat exchanging liquid to chill the carcasses as the carcasses are advanced by movement of the liquid through the tank. 
     Continuous introduction of cold water in one end of the tank and removal of warmer water at the other end of the tank provides the mechanism for removing heat from the carcasses and for moving the carcasses along the length of the tank. The side to side rocking motion of a paddle adjacent the semi-cylindrical bottom wall of the tank tends of distribute the carcasses throughout the volume of heat exchanging liquid, thus assuring more thorough contact between the water and the product and more rapid chilling. 
     An unexpected consequence of paddle type chiller operation has been that carcasses processed in some such chillers retain more moisture than those processed in other types of chillers. Until now, it appears that this moisture retention phenomenon has not been understood or fully exploited. The current invention addresses optimization of moisture retention as well as improving certain operational problems of paddle type chillers. 
     Moisture retention in the poultry carcasses has significant financial implications for the poultry processing industry. The industry typically measures “yield” of the carcasses as the weight of processed carcasses divided by the live weight of birds delivered to the plant expressed as a percentage. Typical yield for whole carcasses can be around 74%. Processing steps that remove moisture from the meat will reduce yield since the weight of moisture removed is not included in the final product. Use of prior art rocker chillers has been shown to increase yield by about 1%. Use of chillers designed according to the current invention has increased yield by an additional 1% or more. To put this in perspective, a 1% increase in yield at a modest size plant processing 400,000 pounds of poultry per day would generate an additional 5400 pounds of salable product with an additional wholesale value of about $840,000 per year at current prices. 
     SUMMARY OF THE DISCLOSURE 
     Briefly described this disclosure concerns a rocker chiller for reducing the temperature of carcasses, such as poultry carcasses received from a processing line that still may be near their normal live temperature of about 104° F. The chiller, which may be a pre-chiller or a final chiller, or the only chiller in the poultry processing line, may include an elongated tank with a semi-cylindrical bottom surface for containing a cold heat exchanging liquid at a liquid level in the tank. An elongated baffle assembly is positioned in the tank and extends along the length of the tank and means, such as a motor, are provided for oscillating the baffle assembly across the curved bottom of the tank for moving the carcasses laterally in the tank through the body of heat-exchanging liquid. The baffle assembly may include a baffle that includes a lower edge adjacent the semi-cylindrical bottom surface of the tank and a body portion that extends upwardly from the lower edge toward the surface of the liquid in the tank. The baffle may include baffle openings sized and shaped to allow the heat-exchanging liquid to pass through the baffle in response to the oscillation of the baffle and to retard the movement of carcasses through the baffle as the heat exchanging liquid rushes about the carcasses. The baffle assembly may include a baffle blade that extends from the lower edge of the baffle and is positioned adjacent the facing curved surface of the tank and provides structural support to the baffle. The baffle defines baffle openings therethrough that are selected from shapes including, for example: circular, non-circular, elongated and polygonal. Other shapes may be used. The baffle openings allow the chilling liquid to rush through the baffle and about the poultry carcasses moving with the baffle. The poultry carcasses tend to become more densely gathered in the heat exchanging liquid when the baffle sweeps in that direction and less densely gathered on the trailing side of the baffle, contributing to a massaging action on the carcass. 
     The rocker chiller disclosed herein may further include a carcass guide shaped for directing the carcasses moving into the tank to alternate sides of the tank, for example, to the side of the tank in which the baffle is positioned. The carcass guide may move in unison with the baffle assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The present disclosure will be better understood with reference to the following drawing figures. Similar reference numerals designate corresponding parts throughout the figures, and components in the figures are not necessarily to scale. 
         FIGS. 1A, 1B and 1C  are perspective sections of a rocker chiller, showing the elongate baffle assembly in its left, centered and right positions, respectively. 
         FIGS. 2A, 2B, 2C, 2D, and 2E, 2F and 2G  are perspective sections of portions of baffle assemblies that include baffles of different configurations that extend from the semi-cylindrical bottom wall upwardly toward the surface of the heat exchanging liquid. 
         FIGS. 3A and 3B  are end views of a baffle assembly with a carcass guide that directs the oncoming carcasses into the chilling heat exchanging liquid. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now in more detail to the drawings in which like numerals indicate like parts throughout the several views,  FIGS. 1A-1C  show a rocker chiller  10  that includes a semi-cylindrical tank  12  that is substantially filled with a body of heat exchanging liquid  14 . The temperature of the heat exchanging liquid may vary in accordance with the carcasses being treated and the manner of treatment of the carcasses. For example, the heat exchanging liquid may be water with antimicrobial and other desirable additives. If the rocker chiller is to be used as a pre-chiller, in which the carcasses of chickens at 104° F. are going to be treated, the temperature of the heat exchanging liquid in the tank may be at about 60° F., a difference of about 44° F. If, however, the principles of the rocker chiller are used in a final chiller tank, the temperature of the heat exchanging liquid might be just above 32° F. 
     In addition to the heat exchanging liquid  14  that substantially fills the tank  12 ,  FIG. 1A  shows that additional heat exchanging liquid may enter the tank by recirculation conduits  16  that direct a cold stream of makeup heat exchanging liquid along the length of the semi-cylindrical bottom wall  19  of the tank, preferably at the predetermined positions above the sweep of the baffle assembly  18 , to be described hereinafter. The makeup liquid entering through the recirculation conduits will be at the desired temperature for the purpose of chilling the carcasses, and tends to urge the carcasses gathered at the upper facing surface of the baffle assembly along the length of the semi-cylindrical tank  12  toward the exit end  13  of the tank. This is disclosed in more detail in U.S. Patent Application Publication 2007/0169502 A1, dated Jul. 26, 2007, the disclosure of which is incorporated herein by reference. 
       FIGS. 1A, 1B and 1C  show the rocker chiller  10  with its baffle assembly  18  in different positions, with the lower edge portion of the baffle assembly to the left, centered and to the right, respectively. It will be appreciated that the baffle assembly  18  substantially divides the heat exchanging liquid  14  into two regions of variable volume depending on the position of the baffle assembly within its range of motion. Due to the design of the baffle, the heat exchanging liquid  14  may freely communicate between the two regions, but the carcasses  28  are at least partially confined to the region in which each was originally introduced. Carcasses in each region will be more or less densely gathered in the heat exchanging liquid as the volume of the region changes due to the motion of the baffle assembly  18 . Alternate cycles of compression and expansion have beneficial effect on the carcasses as will be described more fully in this description. 
     Baffle assembly  18  includes a drive shaft  20  that may extend at the liquid level along the length of the semi-cylindrical tank  12 . Drive shaft  20  oscillates about the longitudinal axis  22 , which may be the longitudinal axis for both the drive shaft  20  and the semi-cylindrical tank  12 . A power means  23  is used to oscillate the drive shaft. An electric motor and gear box may function as the power means. In the embodiment illustrated in  FIGS. 1A-1C , the baffle assembly  18  includes support arms  24  that are mounted at their upper ends to and extend radially downwardly from the drive shaft  20 , with the support arms spaced along the drive shaft. Baffle  26  is formed of parallel spaced apart horizontal slats  30  that are supported at their ends by the radially extending support arms  24 . The chilling liquid in the tank moves through the spaces  29  between the baffle slats  30  in response to the movement of the baffle  26 . The spaces  29  between the baffle slats  30  are too small for most of the poultry carcasses to pass between the baffle slats. The lower edge portion of baffle assembly  18  may include one or more elongated baffle blades  21  that are supported by the radially extending support arms  24  and extend parallel to the drive shaft  20 . The baffle blade  21  of  FIGS. 1A-1C  is sized, shaped and positioned by the support arms  24  so as to sweep closely adjacent the facing semi-cylindrical bottom wall  19  of tank  12 . 
     A conventional drive motor  41  and transmission  40  are connected to the drive shaft  20  of the rocker chiller and function as means for oscillating the baffle assembly  18  in an arc from side to side in the heat exchanging liquid  14  across the interior facing surface of the tank  12 , as shown by arrow  17 . When the baffle assembly oscillates, it sweeps from side to side and tends to engage and move the poultry carcasses  28  adjacent the side wall of the tank toward alignment with recirculation conduits  16  as indicated in  FIGS. 1A and 1C . 
     Poultry carcasses  28  are placed in the tank  12  with the carcasses being generally submerged in the heat exchanging liquid  14 . Most of the carcasses tend to slowly sink toward the bottom of the heat exchanging liquid  14 , adjacent the interior surface of the semi-cylindrical bottom wall of tank  12 . 
     With this arrangement, some of the carcasses  28  are engaged by the baffle  26  and move up with the movement of the baffle and become aligned with the streams of liquid emitted from the recirculation conduits  16  so that the recirculated heat exchanging liquid that may bear an antimicrobial is directed against the carcasses. The drive motor may operate to intermittently pause the baffle assembly  18  at its up positions at the sides of the tank when the baffle assembly is aligned with a recirculation conduit  16 . The oncoming streams of heat exchanging liquid tend to urge the carcasses  28  along the length of the tank  12  toward the discharge end of the tank and to wash the carcasses with the heat exchanging liquid. 
     As shown in  FIGS. 1B and 1C  the baffle  26  extends from the baffle blade  21  at the lower edge of the baffle  26  upwardly toward the drive shaft  20  and toward the surface of the heat exchanging liquid  14 . The parallel slats  30  of baffle  26  have openings  29  extending between them for the passage of the heat exchanging liquid  14  through the baffle as the baffle moves from side to side. These parallel baffle slats  30 , as well as the parallel baffle rods and the parallel baffle bars described hereinbelow and shown in the figures, may be collectively referred to herein as elongate baffle members. 
     The baffle  26  includes openings extending therethrough that may be of various shapes, such as circular, non-circular, elongated, and polygonal. Other shapes of baffle openings may be suitable, as generally shown in  FIGS. 2A-2G . The openings in the baffle  26  are sized and shaped for reducing the likelihood of the carcasses becoming caught in the openings of the baffle but permitting the heat exchanging liquid  14  in the tank  12  to move through the baffle. The baffle may be formed of sheet metal, expanded metal, woven wire, perforated sheet material, one or more slats or a plurality of parallel rods supported by adjacent ones of the support arms  24  or by a plurality of parallel rods extending radially out from the drive shaft  20  and joined or not at the distal ends by a baffle blade  21 . The baffle may be made of materials that are stable and strong in the heat exchanging liquid. Further, the openings in the baffle may be larger than described above, with the spaces allowing movement of carcasses through the baffle. Preferably the openings in the baffle are of a size and shape so that the carcasses do not become caught in the baffle. 
     As shown in  FIG. 2A , the baffle  26 A of baffle assembly  18 A includes a perforated sheet  25 A extending radially downwardly from drive shaft  20  that defines an array of openings  31 A, with the baffle  26 A forming an upward extension of baffle blade  21 A. The perforated sheet may extend from the baffle blade  21 A upwardly to the drive shaft  20 . The radially extending support arms  24 A support the baffle assembly from the drive shaft  20 . 
     As shown in  FIG. 2B , the baffle  26 B of baffle assembly  18 B may be a perforated sheet  25 B that extends radially from drive shaft  20  to baffle blade  21 B. The perforated sheet  25 B also defines an array of openings  31 B, and the baffle  26 B forms an upward extension of baffle blade  21 B. The radially extending support arms  24 B support the baffle assembly from the drive shaft  20 . 
     As shown in  FIG. 2C , the baffle  26 C of baffle assembly  18 C includes a plurality of parallel spaced bars  27 C mounted to and extending downwardly from the drive shaft  20 . Spaces  29 C are formed between the bars  27 C and are sized as previously described, to retard the movement of the poultry carcasses from one side to the other side of the baffle as the baffle oscillates from side-to-side. The bars  27 C are of a length so that the lower ends of the bars move closely adjacent the facing cylindrical surface of the tank so the carcasses are not likely to pass about the end of a bar. 
     As shown in  FIG. 2D , the baffle  26 D of baffle assembly  18 D includes a plurality of parallel spaced bars  27 D mounted to and extending downwardly from the drive shaft  20  and joined (or not) at their lower ends to longitudinally extending baffle blade  21 D. Spaces  29 D are formed between the bars  27 D and are sized as previously described, to retard the movement of the poultry carcasses from one side to the other side of the baffle as the baffle oscillates from side-to-side. 
     As shown in  FIG. 2E , the baffle  26 E of baffle assembly  18 E includes a plurality of horizontally extending parallel spaced bars  27 E positioned between and parallel to the drive shaft  20  and baffle blade  21 E. Spaces  29 E are formed between the bars  27 E and are sized as previously described, to retard the movement of the poultry carcasses from one side to the other side of the baffle  26 E as the baffle oscillates from side-to-side. Radially extending support arms  24 E support the baffle  26 E and baffle blade  21 E from the drive shaft  20 . 
     As shown in  FIG. 2F , the baffle  26 F of baffle assembly  18 F includes at least one wide slat  30 F positioned between the drive shaft  20  and the baffle blade  21 F. Spaces  29 F are formed on opposite sides of baffle slat  30 F and are sized as previously described, to retard the movement of the poultry carcasses from one side to the other side of the baffle as the baffle oscillates from side-to-side. Radially extending support arms  24 F support the baffle  26 F and baffle blade  21 F from the drive shaft  20 . 
     As shown in  FIG. 2G , the baffle  26 G of baffle assembly  18 G includes a baffle board  30 G mounted to the baffle blade  21 G and to the radially extending support arms  24 G. The upper edge  23 G of the baffle board is spaced downwardly from the drive shaft  20  and forms an overflow space  29 G above its upper edge for the movement of chilling liquid. As the baffle assembly  18 G oscillates, the chilling liquid spills over the upper edge  23 G of the baffle board  30 G, causing turbulence of the chilling liquid about the poultry carcasses. 
     While the baffle blades  21 A- 21 G may provide structural and operational advantages in specific cases, it is not necessary to the general function of the baffle which is to allow heat exchanging liquid to pass through while retarding the passage of carcasses. For example, the baffle blade  21 E could be replaced by additional parallel rods  27 E of  FIG. 2E  while retaining adequate structural integrity, and the baffle would function as intended. 
     In some cases, the baffle may be designed with sufficient structural integrity to eliminate the need for the baffle blade and even the support arms.  FIG. 2B  shows a perforated baffle  26 B with a lip  21 B at the lower edge. The lip provides sufficient rigidity to avoid excessive flexure under the loads imposed on the baffle by the oscillating motion. The support arms  24 B of  FIG. 2B  have been reduced to flat ribs which carry the bending load where the baffle attaches to the central drive shaft  20 . 
       FIG. 2C  shows an embodiment in which the baffle consists of a series of radially extending parallel rods  27 C that span from the drive shaft  20  to a length that places the ends of the rods adjacent the inner surface of the tank  12 . The spaces between the ends of the rods  27 C and the tank  12  are small enough that carcasses cannot become wedged between rod and tank, but large enough that the rods do not touch the tank at any point in their range of motion. The rods are designed of such size and strength that each rod can bear the bending load imposed by the local resistance to the oscillatory motion of the baffle assembly. Neither baffle blade nor support arms are required in this embodiment. Note also that the lower edge of this baffle is not a continuous physical edge but rather an imaginary edge interpolated between the distal ends of rods. 
       FIGS. 3A and 3B  illustrate the positions of a baffle assembly  18  when the baffle assembly has moved from one side over to the other side of the semi-cylindrical tank  12 . A carcass guide  40  extends upwardly from drive shaft  20 . The carcass guide  40  may be a plate or other surface that extends in the opposite direction from the drive shaft  20  when compared to the radially extending support arms  24 . 
     The carcass guide may comprise a deflector plate  42  or other guide surface that functions to direct the oncoming carcasses  28  downwardly at a sloped angle into the heat exchanging liquid  14 . As shown in  FIG. 3A , the carcass guide  40  is positioned on the opposite side of the drive shaft  20  from the baffle assembly and the carcass guide moves to the opposite side of the drive shaft  20  in comparison to the movement of the baffle assembly. This causes the carcass guide  40  to deliver the carcasses to the heat exchanging liquid  14  on the side where the baffle assembly  18  is raised in the liquid  14 . When the baffle assembly sweeps to the other side of the tank, as shown in  FIG. 3B , the carcass guide will be extended upwardly to the opposite side in comparison with  FIG. 3A , so as to direct the oncoming poultry carcasses  28  to where the baffle assembly has been raised. This tends to equally divide the oncoming carcasses on opposite sides of the baffle assembly over time. 
     In the current invention, the baffle restricts carcasses from moving through the baffle assembly, and the poultry carcasses  28  tend to become more densely gathered in the turbulent heat exchanging liquid  14  when the baffle assembly  18  sweeps in that direction and less densely gathered on the trailing side of the baffle assembly as shown in  FIGS. 1A, 1B and 1C . 
     The contact of the carcasses with the surfaces of the tank  12 , with the baffle assembly  18  and with one another creates a mild compression of each carcass, providing the benefit of massaging the meat of the carcasses. Repeated cycles of compression and relaxation cumulatively tend to help break down some of the cell structure of the carcasses, thereby tenderizing the meat and creating microscopic voids where moisture can be retained within the product. 
     It is desirable to not only chill the carcasses but to massage the carcasses so that moisture will be retained in the product through the production process. The additional surface area of the baffle provides more contact with the carcasses thus promoting the massaging action. 
     As the poultry carcasses gather more densely on the leading side of the baffle assembly, the heat exchanging liquid rushes through the baffle toward the opposite side of the tank. This is illustrated by the horizontal arrows  44  in  FIG. 1B , showing how the water rushes from the right side, through the baffle of the blade assembly, and then into the left portion of the tank. The rush of heat exchanging liquid tends to push the carcasses against the baffle, further enhancing the massaging effect on the meat. In addition, heat exchanging liquid rushing past the carcasses as they accumulate adjacent the baffle enhances the heat exchange efficiency. This enhanced efficiency assures that the chilling function does not suffer significantly as a result of the asymmetrical distribution of carcasses within the heat exchanging liquid. 
     A result of the new rocker chiller herein disclosed is the washing action of the more vigorous movement and more positively churning of the birds about in the heat exchanging liquid  14 . This vigorous washing function of the carcasses tends to remove bits of organic matter that are usually carried by the carcasses into the heat exchanging liquid. This vigorous churning tends to get more of that substance off the birds and this may be important if the rocker chiller is functioning as a pre-chiller where the birds are first placed for treatment in the pre-chiller and then moved to the final chiller. 
     When the rocker chiller disclosed herein is functioning as a pre-chiller, the temperature of the water in the pre-chiller is usually significantly higher than the temperature of the water in the final chiller, and at the higher temperature the compression and turbulence action experienced in the pre-chiller tends to remove more of the unwanted substances from the surfaces of the carcasses while the surfaces of the carcasses are relatively warm. The warmer surfaces of the carcasses are more subject to being cleansed by the turbulence of the water and the impact against the carcasses. The oil and bits of fat and organic matter on the meat tend to be washed off the carcasses in the chiller when the temperature of the carcasses is still above about 60° F. The combination of the higher temperature and the more vigorous impact and churning of the carcasses provides a cleaner carcass at the exit of the pre-chiller. Thus, these items, skin oil, bits of fat, organic matter, etc. tend to remain in the heat exchanging liquid of the pre-chiller, where it is not transferred to the subsequent main chiller, where disinfectant in the main chiller can be used at a lower concentration for providing the same cleaning results. A stronger dose of disinfectant in the pre-chiller allows a minimal dose of disinfectant in the final chiller. 
     By scrubbing the birds in the pre-chiller, less organic matter is transferred into the final chiller and whatever chlorine or other disinfectant is used is more available to attack the microbes of the carcasses. 
     The cycles of alternate compression and relaxation of the water on opposite sides of the baffle assembly as shown in  FIGS. 1A, 1B and 1C  tends to “massage” the soft tissues of the poultry carcasses and encourage moisture retention. The baffle assembly configuration increases and decreases liquid pressure on opposite sides of the baffle as it sweeps in opposite directions across the tank in a cycle pattern. This change in pressure is relatively small, only a few inches of water head, as shown in  FIGS. 3A and 3B , but when the pressure change is applied repeatedly along the length of the travel of the carcasses, it tends to have an effect of compression and expansion of the bird carcasses, resulting in more water retention and expelling of undesirable surface tissues on the birds. 
     Although preferred embodiments of the invention have been disclosed in detail herein, it will be obvious to those skilled in the art that variations and modifications of the disclosed embodiments can be made without departing from the spirit and scope of the invention as set forth in the following claims.