Meat dewatering assembly

METHODS FOR DRYING EMULSIFIED MEAT

CROSS REFERENCE TO RELATED REQUEST

This application claims the benefit of United States Provisional Application SN 62/459,689, filed February 16, 2017, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates broadly to an improved apparatus for dehydrating various meat products to enable use thereof in large quantities as part of pet food recipes. More particularly, the invention relates to such apparatus which makes use of a pair of counter-rotating, intermeshing, tapered, tapered helical screws located within an apertured casing. The rotation of the screws serves to extract water from the meat, providing a relatively dry product for use in extrudable pet food mixes.

DESCRIPTION OF THE PRIOR ART

Traditionally, kibble-type pet foods have been produced using extrusion equipment. This typically involves the use of a preconditioner that serves to initially moisten and partially cook the feed mix, which includes grains, starches, fats, and other minor ingredients. After preconditioning, the mix is ​​fed to an extruder where it is fully cooked and shaped into a finished product ready for drying and packaging.

In recent years, pet food producers have tried to incorporate increasing amounts of fresh meats into food recipes. At relatively low levels of meat addition, traditional extrusion processing technologies are adequate. However, when attempts are made to incorporate high levels of meat (eg, greater than about 40% by weight), standard extruder/preconditioner equipment may not be adequate. One problem is that fresh meat products have very high moisture contents, and therefore the usual moisture addition steps in the preconditioner and/or extruder make the product too moist for successful extrusion.

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In response to this problem, equipment manufacturers have designed specialized extrusion equipment to handle high moisture food recipes. Another alternative, however, is to dehydrate the meat before it is mixed with the other feed ingredients, thereby at least partially ameliorating the high moisture problem. However, prior dehydration devices have not been able to efficiently dehydrate meat to a low enough level for effective use in pet food recipes.

References of interest include the following: United States Patents No.^you 2,567,219, 4,438,691, 4,565,124, 4,935,183, 5,232,280, 5,333,556, 5,628,560, 5,694,883, 6,234,661, 6,609,819, 6,688217, 6 .805.480, 7.191. 700, 7,322,738, 7,632,006, 7,731,879, 8,079,747, 8,596,856, and 9,316,439; United States Patent Publications No.^you 2005/0219943 and 2008/0069916; Foreign Patent References No.^you CN101103825A, CN101531054A1,

CN102225317A1, CN102275285A1, CN102490340A1, CN201439223U1,

CN202062635U1, DE10113949A1, EP0358837, and WO2004080704; and non-patent publications: Baldwin, Adding flexibility to the extrusion process, Animal Feed, 2007; Bharath, Design of Twin Screw Oil Expeller for Pongamia Pinnata Seeds, International Journal of Emerging Technology and Advance Engineering, 2014; MLA Report, Evaluation and development of high moisture extruded red meat trim products, 2011; and JSW brochure, Twin Screw Extruder, 2014.

SUMMARY OF THE INVENTION

The present invention overcomes the problems set forth above, and provides improved apparatus and methods for dehydrating meat, and particularly aqueous meat mixtures. Broadly, the invention provides dewatering assemblies comprising a pair of interlocking, tapered, non-parallel, elongated helical displacement screws, each screw having a longitudinal axis, the screws being oriented with the included angle between the axes lengths thereof which is about 1-7°, more preferably about 1-5°, and most preferably about 2°. The helical helix of the screws cooperatively exhibits pressure gaps along the length of the screws. A casing is provided in at least partial surrounding relationship with the helical screws, wherein the casing has an inlet opening for an emulsified meat (typically having meat particles no larger than about 3.0mm), a series of outlets for water along at least one

1641663 of 9 part of the length of the carcass, and an output of jerky. A drive is operatively engaged with the screws to counter-rotate the screws during the operation of the dewatering assembly.

The piecewise helical offset screws are oriented to remove water from the emulsified meat by pressing meat particles into the pressure interstices, and the casing is open to atmosphere so that the pressure within the casing is substantially atmospheric (ie plus or minus 3% of actual atmospheric pressure). In preferred forms, apparatus is provided to allow adjustment of the pressure gaps between the helix of the screws.

The invention also provides methods of dehydrating meat-containing slurries comprising the steps of first passing an emulsified meat mixture into and through a meat dehydrating assembly, wherein the assembly comprises a pair of helically displaced screws elongated, not parallel, tapered and meshed. Each of the screws has a longitudinal axis, and the screws are oriented with the included angle between the longitudinal axes thereof from about 1-7°, and the helical helix of the screws cooperatively presents pressure gaps along the length of the screw. screw length. The screws are counter-rotated during the passage of the emulsified meat through the dewatering assembly in order to cause the meat particles within the mixture to be compressed within the pressure interstices in order to expel water from the meat. and allow the recovery of the dehydrated meat. The entire process is carried out at substantially atmospheric pressure.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a perspective view of a meat dehydrating assembly in accordance with the invention;

Fig. 2 is another perspective view of the meat dehydrating assembly, from a different viewing angle;

Fig. 3 is a side elevational view of the meat dewatering assembly;

Fig. 4 is a plan view of the meat dehydration assembly;

Fig. 5 is a top view of the meat dehydrating assembly, with the screw housing removed to illustrate the configuration of the double dehydrating screws;

1641663 of 9 Fig. 6 is an exploded perspective view of the meat dewatering assembly, illustrating alternative casing assemblies and the end screw support frame in its open position;

Fig. 7 is a sectional view illustrating the forward ends of the meshing screws of the meat dewatering assembly, illustrating the pressure gaps between the helices of the screws;

Fig. 8 is an enlarged top view illustrating one of the U-joint/fitting collars that forms a part of the meat dewatering assembly;

Fig. 9 is a perspective view of one of the U-joint/fitting collars that forms a part of the meat dewatering assembly;

Fig. 10 is an exploded view of one of the U-joint/fitting collars which forms a part of the meat dewatering assembly;

Fig. 11 is a fragmentary view illustrating the dewatering slots in the housing of the meat dewatering assembly;

Fig. 12 is an enlarged view similar to Fig. 6, but illustrating in detail the swing frame screw support of the meat dewatering assembly;

Fig. 13 is an exploded view of a modified casing used in another embodiment of the invention and equipped with a first section steam heater; and Fig. 14 is a fragmentary perspective view of the third casing section of the embodiment of Fig. 13, illustrating the pattern of drainage grooves only at the bottom 180° of the casing section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention overcomes the problems set forth above, and provides highly effective, efficient equipment for dehydrating meats of various types, including beef, pork, chicken, turkey, fish, and combinations thereof.

Turning first to Figs. 1-4, a meat dehydrating assembly 10 is shown, generally including an elongated lower support frame 12, a twin screw dehydrating unit 14, a drive assembly 16 operatively coupled with the unit 14, a screw bracket most extreme oscillating, 18, and a water collection gutter 20. As illustrated, the frame 12 supports all of the above components in an in-line manner, from right to left, as seen in Figs. 1, 3, and 4.

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In more detail, the support frame 12 has laterally spaced elongated side members 22, 24, with an intermediate connecting structure 26 and span walls 27 extending therebetween and interconnecting the side members. Drive assembly 16 includes an electric drive motor 28 having an output shaft 30 leading to gearbox 32. The gearbox 32 has a pair of output shaft assemblies 34, 36, each including a first adjusting collar 38, a first interlocking U-joint 40, a short output shaft 42 of the first U-joint 40 to a second U-joint 44, and a second adjustable collar 46.

The dewatering unit 14 includes a pair of uniformly tapered, nonparallel meshing, helical offset screws 52 and 54 each having a central helix region 55, a rearwardly extending drive section 56 that it extends into and is supported within the bearing housing 50, and forwardly extending stub shafts 58. As illustrated, the drive section 56 extends through the bearing housing 50 and is secured to the adjustable collar 46. In the illustrated embodiment, the center lines of the screws 52, 54 have an included angle of 2° between them; more generally, this angle would be about 1-7°, more preferably about 1-5°. Larger included angles of 10° or more would tend to degrade the performance of the assembly 10 by creating unduly high roller pressure conditions in the roller regions between the screws. The regions 55 of the screws 52, 54 have a single helix design, with a uniformly decreasing pitch length from back to front, and a uniformly varying helix depth from back to front. The screw 52 rotates to the left hand, is of variable rotation (from 3.937 inches at the rear end to 2.520 inches at the front end), has a variable screw depth, while the screw 54 rotates to the right hand, is of variable pitch, with a variable screw depth having the same rotation dimensions. Pressure points or pressure gaps 59 are provided between the meshing helices along the length of the screws, which are adjustable in length. It is important to note that the screws are designed and driven to rotate in a counter-rotating manner, that is, they rotate in counterclockwise directions.

The pressure gaps 59 between the meshing helix of the screws 52, 54 (see Fig. 7) can be varied using the adjustment structure described below.

1641663 9 continuation between 0 and 0.161 inches on the large diameter ends of the screws, and 0 to 0.086 inches on the small diameter ends of the screws. In alternative designs, multi-flute screws may be used instead of screws 52, 54, or the screws may be constant-turn or constant-pitch.

The overall unit 14 also includes a perforated open casing assembly 60, which receives screws 52, 54, with drive section 56 extending rearward from the casing, and knuckle shafts 58 extending forward of the casing. As best seen in Fig. 6, the casing assembly 60 is comprised of three end-to-end interconnected tapered sections 62, 64, 66, each having an internal bore 68, 70, 72 shaped like an "8" so as to closely surround the interposed screws 52, 54, that is to say, the casing presents two elongated communication chambers, side by side, where each one surrounds and receives a corresponding screw 52 or 54. The rearmost carcass section 62 is equipped with a tubular meat inlet 74. Sections 62-66 have a series of elongated water drainage slots 76 formed therein. In this embodiment, the slots 76 in section 62 are 1mm wide and 9mm long; the slots 76 in the downstream sections 64 and 66 are smaller, and the slots in section 64 are larger than those in section 66. Furthermore, in the embodiments of Figs. 1-12, slots 76 are provided over the entirety of the casing 60 and along its entire length. As best seen in Figs. 1 and 3, a series of upright supports 78 are secured to side members 22, 24, and extend upwards for connection with the shell sections, thus suspending shell 60 above support frame 12. The open design of the casing ensures that the meat dehydrating operation of the assembly 10 occurs at substantially atmospheric pressures in contrast to typical extruders which normally operate at pressures above atmospheric.

As shown in Fig. 6, use can be made of an alternative housing assembly 60a, which is identical to assembly 60, except that rings 68a, 70a, and 72a have essentially flat midsections and rounded ends. Consequently, the walls of the casing sections 62a, 64a, and 66a do not closely match the configuration of the screws 52, 54 in the engaging regions thereof.

The oscillating screw bracket 18 is mounted at the front end of the

1641663 of 9 support frame 12 by means of a pivot mount 80, allowing support 18 to be selectively moved from a closed position, illustrated in Figs. 1-5, to an open position, illustrated in Fig. 6. A suitable latching structure (see Figs. 6 and 12) is provided to hold bracket 18 in its closed position, with an on/off handle 82. When it is desired to open the bracket, crank 82 is actuated, and the bracket is rotated out to the position of Fig. 6. Bracket 18 is fitted with a fixture 84 which has a pair of side-by-side bearing brackets. 86, which receive the stub axles 58 projecting forward from the screw 52, ​​54; therefore, the screws are supported at both ends thereof during the mounting operation 10.

The water collection trough 20 positioned under the casing 60 is generally U-shaped and designed to receive water drawn through the slots in the casing 76. A suitable water removal structure is provided (not shown). for the drainage of the gutter 20 during the assembly operation 10.

As indicated above, the pressure gaps between the screws 52, 54 can vary. For this purpose, use is made of one or more of the adjusting collars 38. Referring to Figs. 8-10, U-joint/adjustment collar 46/44 is illustrated. Specifically, the rearmost end of drive section 56 of screw 54 is attached to collar 46. Collar 46 has a first radially expanded segment 88 having a pair of opposed lugs 90. Collar 46 also has a second segment 92 which has a pair of opposing lug receiving recesses 94. Segment 92 is attached to universal joint 44 by means of screws 96. Recesses 94 are defined by a pair of projections 98, each with a set screw 100; screws 100 engage lugs 90, as shown. When it is desired to change the relative position of the screw 54 with respect to the screw 52, ​​and therefore change the pressure gaps between them, it is only required to turn one of the adjusting screws 100, which affects a slight rotation of the collar 46, and thus the entire screw 54. Of course, such adjustments can only be made when the assembly 10 is not in operation.

Figure 13 illustrates a modified embodiment in the form of a meat dehydrating assembly 102. In this embodiment, a screw assembly casing 104 is provided comprised of first, second, and third end-to-end interconnected casing sections 106, 108, and 110. The initial casing section 106 is equipped with a surrounding heating steam jacket 112,

1641663 of 9 which serves to heat the emulsified meat introduced through the inlet 114. On the other hand, in this embodiment, the intermediate casing section 108 is equipped with water drainage grooves 76, which cover the entire surface of the section 108 The end section 110 has slots 76 only in the lower half thereof, as best seen in Fig. 14.

It is desirable that the meat to be processed in assembly 10 is first mechanically conditioned into an emulsified form, which may optionally be pre-treated at a temperature of approximately 40-80°C, prior to delivery to inlet 74. The meat then proceeds to along the length of the casing 60 during counter-rotation of the screws 52, 54, where they are driven by means of the drive assembly 16. As the meat travels the length of the casing at substantially atmospheric pressures, the interlocking screws serve to press or squeeze the meat particles into the emulsified meat, thereby extracting water through the casing slots 76 for the purpose of removing the meat. collection inside and removal of the gutter 20. The fully dehydrated meat then passes through the open front end of the casing 60 where it is collected, by a suitable conveyor or other apparatus (not shown) separately from the extracted water. In normal practice, the screws 52, 54 are counter-rotated at a speed of approximately 30-200 rpm, more preferably 50-150 rpm, which differs from typical twin-screw extruders equipped with high-speed co-rotating screws.