| 摘要 |
A vacuum device comprising a by-pass fan pump, a conduit connecting the inlet of the pump to a member in which pressure is to be reduced and a flow passage formation enabling a stream of air to enter the pump and to by-pass the member. In a preferred embodiment the inlet to the by-pass fan pump is connected to the outlet of a Venturi pump and the member is connected to the exhaust inlet of the Venturi pump. The device is directed particularly to the replacement of air by preserving gases in the packaging of foodstuffs.
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