>> Air Blast Freezer
Air blast freezers are not readily available off the shelf as packaged units. They usually have to be tailor-made to suit individual requirements. This note is intended to help the cutomers to specify exactly what he wants, and suggests what information we should then give to enable the customers to make the right choice from what is offered.
The note first describes good design and operation of air blast freezers; this information will be useful both before the freezer is specified and after it has been installed.
In a well designed and correctly operated air blast freezer, the air speed over the products should be about the same everywhere in the freezer, thus ensuring uniform freezing of the product.
The air temperature in an air blast freezer should be low enough to freeze the products as quickly as the code of practice recommends.
Range Temperature – 30 °C. Therefore the air in the freezer has to be lower than – 35°C and, in many commercial blast freezers, an air temperature of – 40°C is found to be practicable.
This important piece of information must be known before attempting to design a suitable freezer.
In an air blast freezer, the shape and size of the freezing space, the size of the coolers and the refrigeration machinery have to be matched to handle a given product load, but because the blast freezer is versatile, a range of products can be accommodated, having different shapes and sizes and different freezing times; it is therefore difficult to predict accurately the most suitable design and to avoid misuse of the freezer once it is in operation.
>> Air Blast Chiller
The differences between Air Blast Freezer and Air Blast Chiller is the temperature. The air temperature of Air Blast Chiller above o °C.