| 摘要 |
<p>A vapor pressure pump for delivering a liquid into a system operating at a higher pressure or located at a higher level by action of a vapor pressure produced from a portion of the liquid to be delivered. The pump comprises a closed reservoir for liquid, which includes an unidirectional liquid inlet, an unidirectional liquid outlet, a vapor exhaust valve adapted to balance the pressure between the unidirectional liquid inlet and the reservoir during its filling. The pump also comprises a vapor generator for producing vapor inside the reservoir at a pressure sufficient to force out the liquid contained therein through the liquid outlet, and a control device for operating the vapor generator only when the liquid fed by the liquid inlet has reached a predetermined level in the reservoir. According to the invention, the vapor generator comprises an evaporation chamber in vapor communication with the closed reservoir, and a device responsive to the control device for sampling a portion of the liquid contained in the reservoir when the liquid in the reservoir has reached the predetermined value, and for supplying the sampled liquid into the evaporation chamber. The vapor generator also comprises a heating system for evaporating the sampled liquid supplied into the evaporation chamber to produce the pressure vapor required to force the liquid out of the reservoir.</p> |
