Pumping system
US4225290A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1979 |
| Grant date | Sep 30, 1980 |
| Priority date | — |
| Expiry date | Feb 22, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2030/326
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved chromatographic pump control circuit for compensating for pulsation in pump flow over a wide range of flow-rates and pressures and for providing improved protection against pump pressure and motor torque fault conditions. The control circuit is coupled to a pump motor to provide motor speed-up during the repressurization portion of the pump cycle as a function of the set point pump flow rate. The circuit also includes a summing circuit for developing a repressurization signal based on the flow-rate and detected pressure. The signal is coupled to compensate for pulsation by controlling the duration of repressurization with respect to both pressure and the set point of the flow rate. The circuit is additionally coupled to sense pump pressure and motor torque to initiate alarm and pump shutdown during high and low pressure and motor over-torque fault conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.