Fumigation of multiple storages with recirculatin g gaseous fumigant

摘要

The simultaneous fumigation of particulate commodities in any number of silos (10) of a storage facility comprising multiple silos, using recirculation of a gas containing fumigant from a single source (17) of fumigant, requires a gas recirculation circuit comprising a gas supply duct (13), a gas outlet duct (14) and a gas connection (15). The silos (10) are included in parallel in the recirculation circuit, their respective inlet ports (11) being connected via respective valves (19) to the gas supply duct (13) and their respective outlet ports (12) being connected to the gas outlet duct (14). Gas movement means (16) circulates gas through the recirculation circuit. A system control valve (25) maintains the pressure of gas in the gas supply duct at a predetermined value irrespective of the number of silos in the recirculation circuit. The gas inlet port (11) of each silo contains an orifice plate (20), the aperture of which is adjusted to ensure a required flow of gas through its associated silo from the gas supply duct. The single source of fumigant supplies fumigant to the gas supply duct (13) to maintain the concentration of fumigant in the gas supply duct at or above a predetermined minimum value.