Patent ID: 6890157
Filing Date: 2005-05-10
Classification: F04B

Abstract:
1. A method for matching or not matching first and second flow rates of respective first and second fluid flows in respective, fluidly-unconnected first and second flow paths, wherein the first flow path includes a first positive displacement pump having a controllable first pump speed which controls the first flow rate, wherein the second flow path includes a second positive displacement pump having a controllable second pump speed which controls the second flow rate and includes a flow-rate transducer downstream of the second positive displacement pump, and wherein the method comprises the steps of: a) shutting off the second positive displacement pump; b) fluidly interconnecting the first and second flow paths creating an interconnected flow path which allows substantially all of a flow of fluid from the first positive displacement pump to encounter the flow-rate transducer; c) after steps a) and b), obtaining a first set of readings from the flow-rate transducer for various values of the first pump speed; d) disconnecting the fluid interconnection between the first and second flow paths; e) turning on the second positive displacement pump; f) after steps d) and e), obtaining a second set of readings from the flow-rate transducer for various values of the second pump speed; and g) substantially matching or not matching the first and second flow rates by controlling one of the first and second pump speeds using the other of the first and second pump speeds and the first and second sets of readings.