METHOD OF FREEZING FRUIT AND VEGETABLES (VERSIONS) AND DEVICE FOR REALIZATION OF THIS METHOD Russian patent published in 2004 - IPC

FIELD: freezing of fruit and vegetables.

SUBSTANCE: proposed method includes motion of product on conveyer belt and delivery of cold air to layer of product at temperature of t_a= - C to -C and partial freezing is performed in cooling part of conveyer; before freezing, product is cooled from surround temperature to temperature on surface of product equal to t_sur=C-C at simultaneous removal of moisture from surface of product by blowing it with descending air flow and partial drying due to mass exchange in dense layer. Proposed method includes motion of product and delivery of cold air at temperature t_a1=-C to -C in freezing part of conveyer; partial freezing is effected in descending air flow in dense layer at attenuating (in way of motion) amplitude of wave and turning the layer first to 0.25 and then to 0.5 and then to 0.75 of its thickness and finally to 1.0 of its thickness. Device proposed for realization of this method includes heat-insulated chamber, conveyer for products, air coolers and fans, loading bin and unloading chute, conveyer drums, transversal partition and longitudinal partition dividing the chamber into zones of increased and decreased pressures; transversal partition divides the chamber into cooling and freezing zones; conveyer is made in form of attenuating wave at oscillation period of T=600-1500 mm and amplitude of oscillation at the beginning A₁=100-160 mm and at the end A₂=0-100 mm and ratio of conveyer length to period of oscillations L/T=1.5- 4 at angle of inclination of conveyer to level =9-20 deg.

EFFECT: fast freezing of products; reduced mass and power characteristics; reduction of production area.

4 cl, 5 dwg