Abstract: A compressor control method includes providing variable aerodynamic sizing of fluid flow through a compressor at multiple operating points of the compressor. A head is determined for an operating point, based on a process input at that operating point. Further, for that operating point, a control pressure number is determined as a function aerodynamic flow sizing at that operating point. The control pressure number is determined a function of the head divided by the square of a tip speed of the impeller of the compressor. An operating speed setpoint is determined based on the determined head and control pressure number.

Abstract: An aeration system (10) which feeds air to multiple water basins (12) and method. A plurality of local processor based control modules (208) is provided. Each module controls the operation of a compressor unit (11) to effect functions including changes in compressor power level, thermal control and blow-off during compressor start-up. The compressor units (11) are assembled in systems and each system is allocated to a different basin so that no two compressors (22) provide air to the same basin (12). A plurality of control operations are performed with a central processor (300) wherein the central processor directly controls aeration valves 324 in each basin 12 based on monitored oxygen levels.

Abstract: An aeration system (10) which feeds air to multiple water basins (12) and method. A plurality of local processor based control modules (208) is provided. Each module controls the operation of a compressor unit (11) to effect functions including changes in compressor power level, thermal control and blow-off during compressor start-up. The compressor units (11) are assembled in systems and each system is allocated to a different basin so that no two compressors (22) provide air to the same basin (12). A plurality of control operations are performed with a central processor (300) wherein the central processor directly controls aeration valves 324 in each basin 12 based on monitored oxygen levels.

Abstract: A compressor control method includes providing variable aerodynamic sizing of fluid flow through a compressor at multiple operating points of the compressor. A head is determined for an operating point, based on a process input at that operating point. Further, for that operating point, a control pressure number is determined as a function aerodynamic flow sizing at that operating point. The control pressure number is determined a function of the head divided by the square of a tip speed of the impeller of the compressor. An operating speed setpoint is determined based on the determined head and control pressure number.