Figure 3: Variation in freezing times for a batch carton freezer with
induced draught air flow.
Perhaps a symptom of the difficulty in achieving adequate air flows is the large variation in fan capacities found in blast cell designs. As an indication, fan power consumption can make anywhere from 20% to 40% of the total freezer heat load.
Figure 4 provides an example of the various heat loads for the blast cell we tested.
Note: a) Using the measure air temperature profile.
b) Using the design air temperature.
c) Using the “required” air temperature.