Studies on the Forced Air Cooler (Part 2)

Performance of Stage Type Forced Air Cooler and Cooling Rate of some Products

Abstract

The results of cooling tests with stage type aircooler for various kinds products are as follows reported, and the possibilities of actually using the cooler are discussed.
1) When cooling citrus unshu by the air-cooler the most efficient air velocity was about 3 meters per second with due regard to fan motor electric consumption. (Fig. 3)
2) When chilled air velocity is constant, the gradient m (hr^-1) of cooling curves for citrus unshu was approximately constant, regardles of the temperature difference Δt between samples and chilling air. (Fig. 4)
3) When cooling citrus unshu, maxmam temperature difference Δt between samples and chilling air should be 20 deg, to make inner temperature difference, δt, of the citrus unshu small.
4) The inner temperature difference of agricultural products, δt, affected severely by the temperature difference between the products and chilling air, Δt.
5) The higher the heaps of products being cooled, the larger the unevenness of cooling, and the higher the velocity of the chilled air, the smaller the unevenness of cooling.
6) In the case of low absolute humidity of the atmosphere, the cooler could cool off 400-1600Kg of agricultural products from 25°C to 4°C in an hour.