
In the fumigation of bulk materials such as grain with hydrogen phosphide (phosphine) the gas containing hydrogen phosphide is caused to circulate in a closed loop passing through the bulk material and past the zone of phosphine generation in pulses having a flow rate, duration and pulse intervals so designed that excessive or dangerous accumulations of gas are avoided and that optimum conditions for pest control are attained throughout the system as soon as possible. The intersticial gas of the...











