Wise maintenance-procedures are essential for achieving high industrial productivities and low energy expenditure. A major part of the energy used in any production process is expended during the maintenance of the em...Wise maintenance-procedures are essential for achieving high industrial productivities and low energy expenditure. A major part of the energy used in any production process is expended during the maintenance of the employed equipment. To ensure plant reliability and equipment availability, a condition-based maintenance policy has been developed in this investigation. In particular, this project explored the use of vibration parameters in the diagnosis of equipment failure. A computer-based diagnostic tool employing an artificial neural-network (ANN) was developed to analyse the ensuing machinery faults, their causes and consequences. For various categories of this type of machinery, a vibration-severity chart (ISO 12372 / BS 4675: 1971) appropriately colour coded according to defined mechanical faults, was used in training of the ANN. The model was validated using data obtained from a centrifugal pump on full load and fed into the program written in Visual Basic. The results revealed that, for centrifugal pumps within 15 to 300kw power range, vibration-velocity amplitude of between 0.9 and 2.7mm/s was within acceptable limits. When the values rose to between 2.8 and 7.0mm/s, closer monitoring and improved understanding of the equipment condition was needed. The evolved diagnostic and prognostic model is applicable for other rotary equipment that is used within the same power limits.展开更多
Most energy-conversion machines (e.g. vehicle engines and electric motors) involve rotating components (e.g. roller bearings and gears), which generate vibrations. The behavior of a pump which includes a deliberate fa...Most energy-conversion machines (e.g. vehicle engines and electric motors) involve rotating components (e.g. roller bearings and gears), which generate vibrations. The behavior of a pump which includes a deliberate fault was chosen to illustrate this assertion. The test bearing at the driven end of the pump’s motor was deliberately damaged using a 1.5mm wire-cutting method and an adjustable coupling disk introduced to impose a shaft misalignment of 40. The resulting undesirable behavior of the pump was observed. Experimental data were measured at various speeds of the rotor. The sample period at various operating frequencies were 0.9, 0.6 and 0.45s respectively. The ball-passage frequency was observed at 4.4, 8.8, 13.2 and 17.6Hz. A computer-based analytical model was developed, in visual basic, for monitoring the machine failures: this led to an integrated system-process algorithm for diagnosis of faults in rotating components.展开更多
文摘Wise maintenance-procedures are essential for achieving high industrial productivities and low energy expenditure. A major part of the energy used in any production process is expended during the maintenance of the employed equipment. To ensure plant reliability and equipment availability, a condition-based maintenance policy has been developed in this investigation. In particular, this project explored the use of vibration parameters in the diagnosis of equipment failure. A computer-based diagnostic tool employing an artificial neural-network (ANN) was developed to analyse the ensuing machinery faults, their causes and consequences. For various categories of this type of machinery, a vibration-severity chart (ISO 12372 / BS 4675: 1971) appropriately colour coded according to defined mechanical faults, was used in training of the ANN. The model was validated using data obtained from a centrifugal pump on full load and fed into the program written in Visual Basic. The results revealed that, for centrifugal pumps within 15 to 300kw power range, vibration-velocity amplitude of between 0.9 and 2.7mm/s was within acceptable limits. When the values rose to between 2.8 and 7.0mm/s, closer monitoring and improved understanding of the equipment condition was needed. The evolved diagnostic and prognostic model is applicable for other rotary equipment that is used within the same power limits.
文摘Most energy-conversion machines (e.g. vehicle engines and electric motors) involve rotating components (e.g. roller bearings and gears), which generate vibrations. The behavior of a pump which includes a deliberate fault was chosen to illustrate this assertion. The test bearing at the driven end of the pump’s motor was deliberately damaged using a 1.5mm wire-cutting method and an adjustable coupling disk introduced to impose a shaft misalignment of 40. The resulting undesirable behavior of the pump was observed. Experimental data were measured at various speeds of the rotor. The sample period at various operating frequencies were 0.9, 0.6 and 0.45s respectively. The ball-passage frequency was observed at 4.4, 8.8, 13.2 and 17.6Hz. A computer-based analytical model was developed, in visual basic, for monitoring the machine failures: this led to an integrated system-process algorithm for diagnosis of faults in rotating components.
