Batch freezer with cryogenic precooling apparatus and method

Abstract

A freezer for a product includes a housing having a chamber therein with an atmosphere for reducing a temperature of the product; a cryogen refrigeration apparatus operationally associated with the chamber during a first cycle to pre-cool the atmosphere in the chamber; and a mechanical refrigeration apparatus operationally associated with the chamber during a second cycle to cool the atmosphere in the chamber when the first cycle is completed. A process is also provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 859,335, filed Jul. 29, 2013.BACKGROUND OF THE INVENTION[0002]The present inventive embodiments relate to batch freezers, and chilling and freezing processes provided by same.[0003]The initial cool down time of known batch freezer systems from room (or ambient) temperature to operating temperature restricts the usable operating time of the system during the day. Cool down times for a batch freezer can exceed one (1) hour. This limitation reduces the amount of product which can be frozen during a single shift or day and therefore, reduces overall efficiency of a plant freezing or chilling process.[0004]During the initial cool down period of a mechanical batch freezer using conventional mechanical refrigeration (such as for example heat exchangers and condensers), the air inside the freezer (chilling or freezing atmosphere) is cooled by passing it across internal ref...

AI Technical Summary

Benefits of technology

The patent describes a cryogen freezer that uses liquid nitrogen or carbon dioxide to quickly cool down products like food. The process is simple and cost-effective, and it reduces the time it takes to cool down the product. This means that production can be increased during the cooling process. The cryogen quickly reaches the product's surface temperature, which prevents further dehydration and allows the mechanical refrigeration system to take over. Overall, this invention makes the cooling process faster and more efficient.

Problems solved by technology

The initial cool down time of known batch freezer systems from room (or ambient) temperature to operating temperature restricts the usable operating time of the system during the day.

This limitation reduces the amount of product which can be frozen during a single shift or day and therefore, reduces overall efficiency of a plant freezing or chilling process.

As a result, moisture from the air collects on these coils and freezes until the internal temperature of the system is cold enough so that all moisture in the air drops out.

The accumulation of ice and snow on the refrigeration coils reduces the convective heat transfer between the internal air and the cods, which in turn results in significant inefficiencies in the mechanical refrigeration process.

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