Brief introduction of tunnel type liquid nitrogen quick freezing machine:

Tunnel type liquid nitrogen quick freezing machine is a kind of large-scale quick freezing machine which is suitable for large production of factory line, and has strong quick freezing capacity; Simple operation and high degree of automation. Tunnel type liquid nitrogen quick freezing machine is suitable for large batch, continuous, less humanized and large area industrial production mode. It can be combined with other food lines to become automatic line. Besides tunnel type liquid nitrogen quick freezing machine with large quick freezing capacity, the company also applies to cabinet type liquid nitrogen quick freezing machine with medium and small production, pure electric compression mechanism cold type and quick frozen liquid quick freezing machine.

Why liquid nitrogen is chosen as the refrigeration medium?

Liquid nitrogen is non-toxic, it is a colorless, transparent and low viscosity liquid. The chemical properties of liquid nitrogen are stable. The boiling point at atmospheric pressure is -196.5 ℃, and it does not react with frozen products, and it is inert to food components. Liquid nitrogen meets the food hygiene requirements. It is an ideal food preservative. The nitrogen content in the air is 78%. It can be said that nitrogen is an inexhaustible environmental refrigerant. Moreover, because of the replacement of air from food, the oxidation change can be reduced to a small extent during freezing and packaging storage.

When the heat absorbed by liquid nitrogen changes to gas at standard atmospheric pressure, 199.29kj/kg latent heat of gasification shall be absorbed, and the heat of 202kj/kg shall be absorbed by the low temperature gas rising from -196.5 ℃ to -10 ℃. Liquid nitrogen is to use this super-low temperature heat absorption property to quickly cool down. At this time, the temperature difference is up to 200 ℃ and the strong heat exchange can make the frozen product freeze in a moment, and the surface forms a hard shell. The water content inside the frozen product will not volatilize, so that the freeze dry consumption rate is extremely low, almost zero. Because the freezing time is too short, 5-10 minutes, it is 1 / 8-1 / 5 of the conventional freezing method. The ice crystals generated in the frozen products are very thin and even. The freezing speed is greater than the steam penetration speed inside and outside the cell. Ice crystals are generated inside and outside the cell, which has no damage to the cell wall. Therefore, the original color, fragrance, taste and fresh state of the frozen product can be maintained after thawing, Liquid nitrogen quick freezing is one of the current fast freezing and preservation techniques of food.

Tunnel type liquid nitrogen quick freezing machine -- Application

Tunnel type liquid nitrogen quick freezing machine is a kind of large-scale quick freezing machine which is suitable for large production of factory line, and has strong quick freezing capacity; Simple operation and high degree of automation. The new heating technology, temperature control technology and liquid nitrogen dispersion technology are adopted in the series of liquid nitrogen quick freezing machines, which make the programmed heating, constant temperature and cooling processes stable. Liquid nitrogen is used as refrigerant to meet the requirements of cooling and environmental protection. The quick freezing equipment has many specifications such as box type, cabinet type and tunnel type, and can be designed and manufactured according to the user requirements.

Freezing speed is fast. Compared with the traditional air forced circulation freezing device, the heat transfer intensity increases by 30-40 times. This is because: the thermal resistance decreases 15-18 times when freezing, the Exothermic Coefficient of product surface and cold air increases by 4-6 times, and the effective heat exchange area increases by 3.5-10 times. So the freezing speed is dozens times higher than that of the ordinary freezing equipment. Because of the fast freezing speed, it can maintain the original nutrition and fresh state of food to a great extent.

The monomer is frozen quickly. After the food freeze, it will not stick together, and realize IQF freezing, which is not only of good quality, but also convenient for packaging and consumer consumption.

The dry consumption of food is low. Each frozen food has a thin ice film on the surface, which is conducive to keeping the food fresh and preventing oxidation, and has less dry consumption. The results of the experiments on mushrooms and strawberries by Swedish scholars show that the dry consumption of liquid nitrogen freezing is almost half of the freezing of forced air supply tunnel. This is particularly important for food with higher prices.

It is easy to realize mechanization and automation continuous production, high production efficiency, and workers operate under normal temperature conditions, which improves the working conditions.

Tunnel type liquid nitrogen quick freezing machine - product advantages:

1. quick freezing time is short, and it is frozen rapidly in 5 to 10 minutes.

2. low water loss and low cell tissue destruction greatly preserved the texture, color and taste of the product.

3. liquid nitrogen is used as refrigerant, which is safe and environmental protection.

4. simple operation.