Water bath shell egg pasteurization system

A shell egg pasteurization system comprising:

• a pasteurization bath containing liquid water and having a series of at least two continuous zones;
• an air supply system supplying air bubbles into the water in the pasteurization bath;
• at least one temperature sensor in each zone of the bath for measuring the water temperature in the zone of the bath;
• a heating system that operates to increase the temperature of the water in each zone of the bath to a temperature set point value, said heating system including at least one independently controlled heating element in each zone of the bath;
• a batch carrier arrangement that holds batches of shell eggs in the bath and includes an advance motor that moves the batch carrier arrangement and thereby the respective batches of shell eggs through and between zones;
• a cooling system that operates to selectively lower the temperature of the water in the pasteurization bath when the temperature in one or more zones approaches an upper temperature limit that is set higher than the temperature set point value;
• and
• a batch processing control system programmed with at least one pasteurization protocol based on a designated size and start temperature of shell eggs in a batch, said protocol setting at least the temperature set point value for the water bath and a total dwell time in the bath for each batch;
• wherein the batch processing control system receives signals from the at least one temperature sensor in each zone of the bath and is configured to operate the heating system to independently raise the temperature of the water in each zone of the bath toward the temperature set point in response to signals from the at least one temperature sensor in each respective zone, is also configured to operate the cooling system to lower the temperature of the water in the bath in response to signals from at least one temperature sensor in the bath in order to maintain the temperature of the water below said upper temperature limit, and is further configured to control the advance motor of the batch carrier arrangement to move the batches of shell eggs through the series of zones in the bath and hold each batch of shell eggs in the water for said total dwell time.