Solar collector which heats air esp. for crop drying - has controlled recycling to maintain uniform conditions

摘要

Solar air collector is made from plastics foil and comprises one or more control devices, which respond to the intensity of the incident solar radiation and/or to temp. changes in the air leaving the collector and/or to other variables. These control devices open or close to a greater or lesser degree a recycling opening so that a portion of the air leaving the collector can be recycled through it. In this way a constant flow of air of uniform value through the collector is obtained with varying temperature conditions, but the total air throughput is increased or reduced accordingly to give a given temperature rise. The collector is particularly for the drying of crops but may also be used for heating.