Tunnel Freezer Manufacturers

Tunnel freezers — design and applications

A tunnel freezer is a straight, insulated freezing tunnel through which product is transported on a conveyor belt while cold air is circulated around the product to freeze it. The belt enters at one end, travels the length of the tunnel, and exits at the other end — the product is frozen continuously during the pass. The tunnel length (10–50m or longer) and belt speed determine the residence time; the refrigeration capacity and air temperature determine the freezing rate. Tunnel freezers are used for a wide range of food products where individual pieces require freezing without tumbling or stacking: fish fillets and portions, meat cuts, processed poultry, vegetables, bread and bakery products, ice cream bars, and fish blocks. Multi-belt tunnel freezers use multiple conveyor belts in series or stacked — the product moves between belts (falls from one level to the next), which also provides gentle tumbling to prevent pieces sticking together. This is particularly useful for vegetables and other small products that benefit from some agitation to prevent stacking.