Spiral freezing is used in food processing and manufacturing. Just as blast freezing, spiral freezing is used to keep production quantity high, and quality consistent. Spiral freezers are composed of a conveyer belt system that “spirals” continuously, speeding up the freezing process. Spiral freezers can have their airflow and temperature adjusted according to item being frozen. They can freeze products individually or in batches. Products can be frozen quickly and uniformly without large ice crystals forming, preventing damage to the product.
The construction of spiral freezers depends on the installation. Spiral freezers are great for areas that have horizontal space limitations, but not vertical ones. Spiral freezers also have a subset of freezers called individual quick freezers, or IDQs.
IDQs are used for food products with short shelf lives. The “individual” aspect is emphasized when food needs to be frozen, but it needs to be kept in certain packages for resale. Heat transfer is optimal in this type of freezing. Heat transfer occurs in one stage of IDQ. The first stage is when food is passed over with cold air from a centrifugal fan. This is occurs when food is transferred onto the conveyor belt. The conveyer belt keeps food in motion to stop clumping. This is done by eccentric bearings. The conveyer belt and bearings also reduce the contact time on the conveyor belt.