5.0 CONCLUSION
The blast cell tests undertaken have highlighted several weaknesses in the design and operation of blast cell freezers. Plants need to understand that blast cell freezers can freeze only a given product load for a given design refrigeration capacity, and that any change in any one of a multitude of production or carton parameters will often make significant difference to the freezing time.
Also uniform air flow is difficult to achieve in blast cell freezers, there is certainly potential to develop improved guidelines for sizing freezer fans, designing better freezer layouts, and calculating more accurately time variable heat load profiles. This will, however, only slightly improve the problems associated with blast cells, not cure them.
Above all else, what tests show is that there is a significant inconsistency in product temperatures on exiting the unit due to:
- Inconsisent loading factors.
- Variation in product, packaging, and stacking.
- Incorrect design.