A freezing tunnel is a type of instant quick freezer (IQF). Unlike the plate freezers and the spiral freezers, the freezing tunnel usually travels horizontally through a long-enclosed compartment (cold tunnel) and the cold air is circulated upward through the product. The product is conveyed through the freezing tunnel by a series of stainless steel or plastic mesh belts.
The principle of the Tunnel Freezer is based on the circulation of air at a very high speed and at a temperature of around -35°C. It will allow a rapid drop in product temperature to stabilize the product at around -18°C/-20°C at the core. The freezing speed is essential to preserve the quality of the food. The process itself allows freezing the essential nutrients and vitamins of the food. With this mode of freezing the formation of ice crystals of very small sizes will not damage the tissues of the product. With a low exudation at the time of thawing, the foodstuffs will thus preserve all their gustatory qualities.
Please be noted that the freezing process would be completely degraded during a slow freezing type negative cold room for food conservation (-18/-20°C). The formation of larger crystals would damage the wall of the cells by altering the product which will lose water during thawing.
The straight freezing tunnel is capable of freezing and chilling a wide variety of products as part of the continuous processing operation. The customizable freezers are designed to be adaptable to meet the demands of the modern food processing industry. The SFT continuous freezing tunnels incorporate many proven technologies to ensure quick thorough freezing and maintaining the quality attributes of the products.
Benefits for IQF tunnel freezer/ fluidized tunnel freezer:
- Best flavor, texture, and moisture retention
- The best quality product, no damages to the products
- Flexible to freeze various products
- High efficiency of chilling/freezing
- Automated control, continuous operation
- Minimum maintenance and operating cost
The SFT freezing tunnels have the advantages of being very flexible in use. It allows the freezing of a wide variety of foods of different sizes and shapes such as meat products, fish, cephalopods, shellfish, fruits and vegetables, and ready meals.
To customize every particular requirement, we designed and developed the different types of freezing tunnels (listed below)
Continuous Freezing Tunnels of stainless-steel/poly contact belt (single belt)
SFT contact belt freezing tunnel consists of the cold-rolled stainless steel band, aluminum air units (evaporators), insulated enclosure, control panel, and supporting frames. Completely assembled and pre-wired in modular sections, for easy installation and for future expansion in freezing capacity. Pre-assembled at our factory and fully tested to be easily assembled on site
The SFT contact belt freezing tunnels are used for wet, fluid or soft high moisture products or soft extruded products. Also cooked or fried products requiring no marking on product such as fish fillets.
Red meat industry: raw meat, hamburger patties
Seafood industry: raw scallops, fish fillets, raw shrimp Others: products in trays at reduced capacity, products in slush or extruded forms
Continuous Freezing Tunnels of Two or Multiple Belts
The freezer is a continuous in-line-belt freezer designed to minimize product weight loss and assure quality gentle handling during freezing. Completely factory assembled and designed to minimize site installation time.
The multipass tunnel freezers are designed to freeze or chill any product. Product larger than 1/2 inch round or thick without any surface moisture such as Italian Pasta product, fried breaded/battered product.
Poultry industry: chicken parts, chicken nuggets
Red meat industry: meatballs
Seafood industry: fish sticks, raw shrimp, fish fillets
Packaged Fluidized Tunnel Freezers
The cascade belt is an inclined twin-belt for providing positive conveying of products. The product is mechanically agitated in a thin layer on the first belt crust-frozen to seal in the moisture. The packaged freezer is pre-assembled and tested at our plant ready to be placed at your plant site.
The fluidized tunnel freezer is generally used for IQF. Small particles range from 3/16 to 2-inch diameter.
Vegetable industry: peas, green beans, cut corn, mushrooms, vegetables, french fries, cob corn, diced carrots, diced onion, cut cauliflower, cut broccoli, cut asparagus, brussel sprouts.
Fruit industry: blueberries, cranberries, strawberries, cherries, gooseberries, raspberries, diced pineapples, sliced apple. Seafood industry: cooked shrimp, skin on shrimp, scallops.
Packaged Brine Tunnel Freezers
SFT sealwelded packaged brine tunnel freezer combines compactness with a highly efficient conveying and freezing system, ideally suited to handle a wide variety of foods.
SFT sealwelded packaged brine tunnel freezers are completely factory assembled, wired and tested, for the minimum site installation time. Units are shipped in separated pieces and joined at the job site. The packaged brine tunnel freezers are designed to freeze a wide variety of seafood products. Such as Shrimp, Fish, and others. Application is for saltwater seafood with skin protection only as it enhances the taste.
Impingement Tunnel Freezers
The SFT impingement tunnel freezers utilize a solid flat top polyethylene belt, which allows for gentle handling of the product and leaves no surface marks. High-efficiency evaporators and fans, with a combination of concentrated air jets, are used to achieve fast freezing time with minimum dehydration of the product. The entire system is enclosed with a stainless-steel finish high-efficiency insulated enclosure.
The SFT impingement tunnel freezers are completely packaged and ready to be moved into place. All that is needed is to install the belt and connect services such as electric power, water, and refrigeration system. The SFT impingement tunnel freezers are designed to freeze a wide variety of wet and soft products. Products such as raw meat, fish fillet, scallops, shrimp, squid, and extruded products.
For more information of our tunnel freezer, please contact us.
WATCH VIDEO. IQF tunnel freezer