Shell Egg Pasteurization System and Method

Abstract

A hatch processing control system for a shell egg pasteurizer controls the time and temperature in which batches of shell eggs are held in a pasteurization bath in accordance with a predetermined pasteurization protocol for designated egg size and start temperature. The predetermined pasteurization protocol is preferably statistically verified to optimize batches of eggs having the designated size and start temperature. The system also includes reporting software that generates daily reports to track each respective batch and verify that the batch has been pasteurized according to the statistically verified protocol.

1 - 23 . (canceled) 
     
     
         24 . A shell egg pasteurization method, comprising the acts of:
 providing a bath containing a fluid pasteurization medium, wherein the bath comprises a series of zones;   providing a batch carrier arrangement for advancing batches of shell eggs through the zones of the bath;   sensing the temperature of the fluid pasteurization medium in each zone of the bath;   providing a heating system for selectively raising the temperature of the fluid pasteurization medium in each zone of the bath, wherein the heating system includes at least one independently controlled heating element in each zone of the bath;   providing a cooling system for selectively lowering the temperature of the fluid pasteurization medium in the bath;   providing a pressurized air supply system in communication with the bath; and   operating a batch processing control system according to a pasteurization protocol selected from a plurality of predetermined pasteurization protocols, wherein each pasteurization protocol is based on a designated size and start temperature of shell eggs in a batch and sets a temperature set point value for the fluid pasteurization medium in the bath, an upper temperature limit for the fluid pasteurization medium in the bath, a level of air pressure for air flowing into the bath and a total dwell time in the bath for the batch, wherein the act of operating the batch processing control system comprises:
 selecting a pasteurization protocol for a batch of shell eggs; 
 controlling operation of the heating system to independently raise the temperature of the fluid pasteurization medium in each zone of the bath toward the temperature set point for the selected protocol in response to the act of sensing the temperature of the fluid pasteurization medium in each respective zone; 
 selectively operating the cooling system to lower the temperature of the fluid pasteurization medium in the bath in response to the act of sensing the temperature of the fluid pasteurization medium, to maintain the temperature of the fluid pasteurization medium below the upper temperature limit established by the selected pasteurization protocol; 
 controlling, movement of the batch carrier arrangement through the series of zones of the bath to bold each batch of shell eggs in the fluid pasteurization medium for a total dwell time selected in accordance with the selected pasteurization protocol; and 
   controlling operation of the pressurized air supply system in accordance with selected pasteurization protocol to control the level of air pressure of air flowing into the bath.   
     
     
         25 . The shell egg pasteurization method as recited in  claim 24 , wherein each predetermined pasteurization protocol for time and temperature is statistically verified for maintaining a central portion of the egg yolk at a temperature level for a period of time necessary to achieve a pre-selected reduction in  Salmonella  species present in the egg yolk in order to thoroughly pasteurize an egg having the designated size and start temperature. 
     
     
         26 . The shell egg pasteurization method as recited in  claim 25 , wherein the act of controlling operation of the—heating system is carried out by circulating heated fluid through a coil-type heating system in each zone. 
     
     
         27 . The shell egg pasteurization method as recited in  claim 25 , wherein the act of selectively operating the cooling system is carried out by introducing cold fluid pasteurization medium into the bath. 
     
     
         28 . The shell egg pasteurization method as recited in  claim 25  wherein the predetermined protocol for a batch of eggs with the designated size and start temperature defines at least two predetermined temperature ranges with one being assigned to a first portion of a total dwell time wherein a temperature set point the first predetermined temperature range is a higher temperature than the temperature set points of subsequent predetermined temperature ranges. 
     
     
         29 . The shell egg pasteurization method as recited in  claim 28  wherein the act of operating the batch processing control system is carried out using software embodied in a non-transitory machine readable form and containing the predetermined pasteurization protocols, each being customized for a distinct combination of egg size and start temperature, and further comprising the acts of providing an electronically controlled valve operatively interconnected with the batch processing control system, and a programmable logic controller that is programmed with a PID algorithm using a temperature set point value defined by said predetermined pasteurization protocol, said algorithm receiving a temperature feedback signal provided to the programmable logic controller and generating a valve control signal that is transmitted from the PLC to the electronically controlled valve in order to control the flow of heated fluid pasteurization medium in the zone beating system. 
     
     
         30 . The shell egg pasteurization method as recited in  claim 25  wherein each of the individually controlled heating elements comprises a beating coil located in one of the zones of the bath and an electronically controlled valve associated with the respective heating coil to control flow of heated fluid pasteurization medium through the respective beating coil, and wherein the batch processing, control system comprises a programmable logic controller which is programmed with a PID algorithm for each of the individually controlled heating coils, each said PID algorithm using a temperature set point value defined by the selected predetermined pasteurization protocol and receiving a temperature feedback signal provided to the programmable logic controller from a temperature sensor associated with the respective heating coil, and each of said PID algorithms generates a heating control signal that is transferred from the PLC to control operation of the respective heating coil. 
     
     
         31 . The shell egg pasteurization method as recited in  claim 30  wherein the zone heating system comprises a boiler for heating the fluid pasteurization medium to a predetermined boiler temperature and the programmable logic controller in the batch processing control system further comprises a PID algorithm to control the operation of the boiler, said PID algorithm for the boiler using a temperature set point value defined by said predetermined pasteurization protocol and receiving a temperature feedback signal provided to the programmable logic controller from a temperature sensor associated with the boiler, and generating a boiler control signal that is transmitted from the PLC to electronically control operation of the boiler. 
     
     
         32 . The shell egg pasteurization method as recited in  claim 25  wherein the batch processing control system controls an advance motor to move the batch carrier arrangement and thereby the respective hatches of shell eggs through and between zones in accordance with the selected predetermined pasteurization protocol for the hatches of shell eggs being pasteurized. 
     
     
         33 . The shell egg pasteurization method as recited in  claim 25  further comprising providing data from the batch processing control system to as computer for each batch of shell eggs being pasteurized, said data including a batch identification number, an identification of the type of batch based on the size and start temperature of the shell eggs in the batch, the batch start time, and the temperature of the fluid pasteurization medium in which the batch is located per time period of the pasteurization process, and further comprising the act of operating the computer to provide a printable report indicating the data for each batch of eggs pasteurized for a given time period. 
     
     
         34 . The shell egg pasteurization method as recited in  claim 33  wherein the report contains data for all batches of shell eggs pasteurized through the system for a given day. 
     
     
         35 . The shell egg pasteurization method as recited in  claim 34  wherein the printable report contains a plot that graphically depicts the time and temperature of the fluid pasteurization medium in which each batch is located per time period of the pasteurization process. 
     
     
         36 . The shell egg pasteurization method as recited in  claim 25  wherein each said predetermined pasteurization protocol sets a lower temperature limit in addition to the upper temperature limit and the temperature set point for the fluid pasteurization medium and the method further comprises the act of operating a sensory alarm located at or near an exit of the pasteurization bath, the alarm providing an on-site sensory indication when an exiting batch falls out of compliance with respect to the upper temperature limit, the lower temperature limit or the total dwell time of the selected predetermined pasteurization protocol.