| 摘要 |
<p>A vacuum device comprising a by-pass fan pump, a conduit (6) connecting the inlet of the pump to a member (8) in which pressure is to be reduced and means 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 (4) 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. </p> |
