| 摘要 |
2085899 9119671 PCTABS00008 Phosphine is generated by the reaction of water with a metal phosphide formulation. In one embodiment, the formulation is within a housing (10) closed by a membrane (12) which is permeable to water and phosphine. A water-containing gas flows across the membrane and water from the gas permeates into the housing to react with the phosphide, producing phosphine which also permeates through the membrane to enter the gas flow. Two membranes (12A, 12B) may be used to close the housing, one permeable to water, the other permeable to phosphine. A blanking plate (17) and phosphine absorber (18) may be included to control the phosphine production. In a second embodiment, pellets of a phosphide formulation are transferred, periodically, from a hopper (23) to a chamber (24) containing water. The transfer is effected by a disc member (25) mounted below the hopper and above the chamber. The disc member has at least one aperture in it, within which pellets are transported from the hopper outlet to an inlet port of the chamber. Control of the phosphine production is supplemented by varying the water temperature and by using a safety arrangement adapted to supply a purge gas to the generator. The safety arrangement utilises a reservoir (73) of the purge gas (usually dry air, nitrogen or carbon dioxide) at high pressure, established prior to the operation of the phosphine generator. If the electrical power supply to the generator fails, or if the gas pressure or the phosphine concentration in the generator is too high, a valve (78) opens to let the purge gas flow from the reservoir into the generator.
|
