USE OF A MICROPROCESSOR CONTROLLED EXPANSION VALVE FOR HIGH HUMIDITY STORAGE OF VEGETABLES

A very low water vapor pressure deficit is necessary for optimal storage results of most vegetable kinds. Up to now those conditions have only been obtained using special constructions. Due to the high costs of those storage systems they are not widely used in horticultural practice. A new possibility for reaching low water vapor pressure deficit in common directly cooled storage come with the use of a microprocessor controlled motor driven expansion valve.

Construction and possibilities of the system are described. Temperature and humidity development in a storage room are shown. The effectiveness of the system is compared with a common cold storage system (using a thermal controlled expansion valve) by means of Chinese cabbage storage. Calculation of the economics of both systems is included.