Abstract: A system for dehydrating lubricating and hydraulic fluids includes a heating circuit and circuitry for creating a vacuum. The heating circuitry introduces a stream of heated fluid into a vacuum chamber in which a partial vacuum is drawn by the vacuum circuit. Aqueous components of the fluid stream are flashed in the vacuum chamber by virtue of the elevated temperature and reduced pressure. Dehydrated fluid is then collected and evacuated from the vacuum chamber. Vapor from the vacuum chamber, including the aqueous components of the fluid stream are collected, condensed and separately evacuated. The heating circuit limits surface temperature of a heating element in a closed-loop manner to avoid degradation of the fluid. The fluid stream is introduced into the vacuum chamber or is recirculated through the heating circuit to maintain a desired level of fluid temperature in a closed-loop manner.

Abstract: A system is provided for closed-loop control of a plurality of metering pumps driven by a single source of pressurized fluid. Feedback signals are generated that are proportional to output flow rate from each metering pump, such as velocity of a movable element of the pump with respect to a stationary element. Flow control valves are coupled between the source of pressurized fluid and the metering pumps. A controller receives the feedback signals and regulates flow from the flow control valves to each metering pump to maintain a desired level of output flow. The source of pressurized fluid may include a pressure compensated positive displacement pump having a maximum output flow rate at least equal to the anticipated combined flow rate of drive sections of the metering pumps.

Abstract: A system for metering a fluid, such as a catalyst in an industrial chemical process plant, includes a controller, a drive pump assembly and an injection pump assembly. The drive pump assembly forces reciprocation of the injection pump assembly via a controlled flow of hydraulic fluid. The injection pump assembly includes a drive cylinder and at least one injection section. The drive cylinder receives pressurized fluid from the drive pump assembly and causes metered fluid to be drawn into and expelled by the injection section. The position of reciprocating components of the injection pump assembly is detected between stroke limits and converted to a velocity signal. Closed-loop control of the flow from the injection pump assembly is implemented by the controller via the drive pump assembly based upon the actual velocity of the reciprocating components of the injection pump assembly and a commanded velocity.