Foods and beverages: apparatus – Cooking – Boiler or deep fat fryer type
Reexamination Certificate
2002-06-14
2004-11-16
Alexander, Reginald L. (Department: 1761)
Foods and beverages: apparatus
Cooking
Boiler or deep fat fryer type
C099S407000, C099S44300R, C099S450000
Reexamination Certificate
active
06817284
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a food product processing apparatus for processing food product, a food product transport mechanism, a lift used to remove food product from the apparatus, and a method of operating the apparatus, and more particularly to a food product transport mechanism for a food product processing apparatus that has a perforate lift that possesses improved dewatering capabilities.
BACKGROUND OF THE INVENTION
Commercial food processing equipment, such as blanchers, steamers, cookers, and coolers, have been used to process food product, such as pasta, vegetables, meats, sauces, juices, pastes, mixed food product, pouched food product, noodles, macaroni, and other types of food product in large quantities. Such food processing equipment usually utilizes a tank equipped with an inlet through which food product to be processed enters. A food product transport mechanism in the tank moves the food product along the tank from adjacent the inlet to adjacent an outlet where a lift is used to remove food product by delivering it to a discharge. The tank typically holds a fluid heat transfer medium that contacts the food product in the tank to process the food product by changing its temperature to heat or cool the food product.
Types of food processing equipment used to process food product using a heat transfer medium include blanchers, cookers, cooker-coolers, and steamers. A rotating auger is a preferred type of food product transport mechanism used in such equipment to urge food product from adjacent the inlet end of the tank toward the discharge end. The auger is equipped with at least one lift located adjacent the discharge to scoop up and discharge food product from the tank. The lift typically comprises one or more perforate lift buckets. In many instances, the auger is equipped with several such lift buckets. While in the tank, a liquid heat transfer medium typically is used to heat the food product. The rate of rotation of the auger is selected to control the amount of time the food product resides in the tank, i.e., residency time, to help achieve a desired amount of processing.
Other types of food processing equipment are used to process food product by removing heat. For example, chillers and coolers are often used to cool food product, such as after it has been heated, so that the food product can be more quickly frozen or packaged for shipment. The food product transport mechanism, which typically also is an auger, urges food product along the tank until it is discharged by the lift. The heat transfer medium used to cool the food product typically also is a liquid.
Each lift bucket is made from a flat sheet of metal, typically of 16 gauge stainless steel, that is punched or laser cut to create several sets of dewatering perforations in it. In one known prior art lift bucket depicted in
FIG. 2
, each such perforation is oval in shape, extends completely through the sheet, and has a width of about ⅛ inch and a length of about ¾ inch such that the total open area of the perforations is no more than 18% of the total bucket surface area. Lift buckets of this construction having perforations with a width of {fraction (1/16)} of an inch or {fraction (5/32)} of an inch have also been used. The bucket also has a bend that helps contour the bucket so it facilitates discharge of the food product. An angled or inclined flange is attached to a bucket side edge to help guide food product into the bucket. The other bucket side edge is attached to an endwall of the auger located adjacent the discharge. As the lift bucket scoops up food product, the perforations dewater food product by permitting liquid heat transfer medium on the food product and on the bucket to pass through the bucket and return to the tank. By preventing loss of heat transfer medium out the tank discharge, less makeup liquid processing medium must be added to the tank during operation which thereby also reduces the energy that must be expended to heat or cool the fluid in the tank to keep it at a desired temperature.
Unfortunately, there is an auger rotational speed limit above which all of the liquid scooped up by such a prior art perforated bucket will not pass through the perforations before the bucket reaches the discharge position. This typically happens at an auger speed of between about 3 to 4 revolutions per minute (RPM), depending on the type of food product. When this happens, some of the liquid food product processing medium remains in the bucket and on food product in the bucket when the food product is discharged. As a result, some of the liquid also ends up being discharged.
When liquid food product processing medium is lost, it must be replaced. Energy must be expended to pump makeup liquid into the tank and to heat or cool the liquid until it corresponds to a desired tank temperature, all of which increases operating costs. Additionally, the auger cannot be rotated much faster than this speed limit without the buckets essentially pumping even larger amounts of liquid out the discharge. As a result, each food processing machine equipped with the aforementioned prior art lift buckets has a rotational speed limit that undesirably limits its food product processing throughput.
Unfortunately, it is believed that there is little room, if any, to improve the dewatering capacity of the prior art lift buckets. Increasing dewatering capacity is not as simple as adding more perforations or increasing the size of each perforation. Increasing the perforation width beyond ⅛ of an inch can cause food product to hang up and plug the perforations, which then significantly decreases dewatering capacity. Adding more or larger perforations beyond what is presently done causes warping of the bucket. Increasing the thickness of the steel sheet material to permit adding more or larger perforations while attempting to avoid warping also is not the answer because increasing sheet thickness limits the size of each perforation that can be punched. Generally, where the perforations are punched, the size of each perforation can be no larger than 1.5 times steel sheet thickness. The size of laser cut perforations in steel sheeting has generally been viewed as being limited in a similar manner. Additionally, even if it is assumed that these technical difficulties can be overcome, laser cutting is generally less favored than punching because it is more costly and less efficient. As a result, it is generally viewed that increased auger speeds simply cannot be attained using lift buckets of this prior art construction.
What is needed is an improved lift bucket and method of operation that permits increasing auger speeds without increasing loss of liquid from the tank.
SUMMARY OF THE INVENTION
The present invention is directed to a food product processing apparatus for processing food product, a food product transport mechanism, a lift used to remove food product from the apparatus, and a method of operating the apparatus where food product processing throughput can be increased while dewatering the processed food products being discharged. A perforate lift comprised of a perforate grid or latticework provides greater open area to increase dewatering at greater food product processing throughput rates.
In one preferred embodiment, the lift is comprised of a plurality of perforate lift buckets that each have at least 24% dewatering open area to provide increased dewatering capacity as compared to prior art lift buckets. Each lift bucket is comprised of grid structure or latticework structure. One such preferred structure includes food product carrying wires that are spaced apart to define dewatering perforations between each pair of adjacent wires. The food product carrying wires are supported by wires that preferably comprise wire retainers that can be clips that engage the food product carrying wires.
In one preferred embodiment, each perforate lift of the invention comprises a lift bucket made of a plurality of pairs of spaced apart and parallel slats that are carried b
Alexander Reginald L.
Boyle Fredrickson Newholm Stein & Gratz S.C.
Lyco Manufacturing Inc.
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