Studies on the Air-Cooling of Farm Products (I)

On the Cooling Rate of NATSU DAIDAI

Abstract

The authors designed the laboratory scale installations of room cooling and forced-air cooling, and the characteristics of the cooling rates of NATSU DAIDAI in some packages were studied in various conditions, i. e. stacking pattern, vent-opening and the rate of air flow. Results obtained were as follows:
(1) The half cooling time of NATSU DAIDAI located in the center of standard carton was 10.8hr, for room cooling and 6.3hr, for forced-air cooling. The irregularity of the cooling rate for room cooling was smaller than that of forced air cooling. (Fig. 2, 3)
(2) The effectiveness of vent hole was remarkable for forced-air cooling. (Fig. 2)
(3) The cooling rate of forced air for lidless carton was very large, especially, when the cold air was blasted to the exposed NATSU DAIDAI. The half cooling time of NATSUD AIDAI located in the center of box was 1.3hr. (Fig. 4)
(4) It was not so effective for the purpose of cooling to leave wide space between the cartons. compared with narrow one (Fig. 5)
(5) The slopes of cooling curves in non-vented carton were parallel (Fig. 6)
(6) It is necessary to pay following attentions in the cutting of vent hole on the carton. (Fig. 7, 8, 9)
1) The vent hole should be bored in the perpendicularly plane to the forced air.
2) Vent hole Should be bored in the lower part of the plane
3) The area of vent hole of 5% is large enough 5 percent from the point of cooling.
(7) Vented carton is better from the point of cooling compared with non-vented carton accompanied with highly increased air flow. (Eig. 10)