초록 ▼

An improved dual-stage pump system is provided for the accurate pumping and filtering of viscous fluids. Two hydraulically activated pumps are provided in series with a filter and reservoir disposed in-line between the two pumps. The reservoir acts as a source bottle for the second pump and allows t

An improved dual-stage pump system is provided for the accurate pumping and filtering of viscous fluids. Two hydraulically activated pumps are provided in series with a filter and reservoir disposed in-line between the two pumps. The reservoir acts as a source bottle for the second pump and allows the first pump to pump the viscous fluid through the filter at a rate independent of the dispensing rate of the second pump. By operating the first pump at a rate independent of the second pump, back pressure at the filter is avoided. Each hydraulically activated diaphragm pump is equipped with an improved diaphragm that is pre-formed to the geometries of the process fluid cavity thereby eliminating any inaccuracies in the operation of the pumps due to expansion of retraction of the diaphragm during pump operation.

대표청구항 ▼

A dual stage pump system for pumping and filtering high viscosity fluids, the system comprising: a first pump for pumping fluid from an input source through a filtering media and into a reservoir, the filtering media disposed between the first pump and the reservoir, the first pump being capable of

A dual stage pump system for pumping and filtering high viscosity fluids, the system comprising: a first pump for pumping fluid from an input source through a filtering media and into a reservoir, the filtering media disposed between the first pump and the reservoir, the first pump being capable of pumping liquid through the filtering media to the reservoir, the reservoir disposed between filtering media and a second pump, the second pump being capable of withdrawing liquid from the reservoir, the reservoir providing filtered fluid to the second pumping means, the second pump pumping fluid received from the reservoir means through a discharge outlet of said second pump, wherein the discharge outlet of the second pump is connected to a three-way valve, said valve having at least two alternative positions including one position in which the discharge outlet is in communication with a dispensing outlet, and a second position in which the discharge outlet is in communication with a recirculation conduit, the recirculation conduit being in communication with a input source of fluid to the first pumping means.