Patent ID: 8517693

Claim:
A method of cooling the working fluid of multiple variable speed hydraulic torque converters in a string of rotating power equipment including a prime mover driving multiple compressors, and multiple variable speed fluid torque converters for starting at least one of said compressors followed by other torque converters starting other compressors, in succession, said prime mover being connected to a first variable speed fluid drive torque converter, and said first torque converter being connected to a first compressor, and a second torque converter connected to said first compressor and in turn connected to a second of said compressors, at least a third torque converter connected to said second compressor and in turn connected to a third of said compressors, said torque converters and said compressors being positioned in an in-series configuration, each of said torque converters providing an output from zero to full speed, each of said torque converters including a supply conduit for cooled working fluid, and a discharge conduit for the heated working fluid, said supply conduit and said discharge conduit for each of said torque converters being connected to a single heat exchanger, and including a discharge valve in each of said discharge conduits and a supply valve in each of said supply conduits, wherein each torque converter includes a lock-up mechanism, engaged at full speed, whereby all power is transmitted mechanically and the input and output speed is synchronized, wherein the method comprises: starting the prime mover; opening the supply and discharge valves of said first torque converter while keeping all other valves to said second and third torque converters closed to permit the working fluid to flow through said first converter and said single heat exchanger; starting said first compressor and increasing the speed up to full speed; closing the supply and discharge valves to said first torque converter; opening the supply and discharge valves to said second torque converter while keeping all other valves closed to permit the working fluid to flow through said second torque converter and said single heat exchanger; starting said second compressor and increasing its speed to full speed; and closing the supply and discharge valves to said second torque converter, opening the supply and discharge valves of said third torque converter while keeping all other valves to said first and second torque converters closed to permit the working fluid to flow through said third converter and said single heat exchanger; starting said third compressor and increasing the speed up to full speed; closing the supply and discharge valves to said third torque converter; whereby each of said torque converters can be successively isolated from said single heat exchanger in turn and each of the torque converters is locked up at full speed, successively, to enable full power transmission mechanically such that working fluid is no longer required.