The high-Yau
              Kaifeng Group of the Yellow River Air Separation 
    Abstract: a large group of centrifugal air compressors axial force on-line monitoring of data in the process of testing the application.
    I. Overview
    Key words: centrifugal air compressors, axial force monitoring device, the shaft vibration, application.
    Large group of centrifugal air compressors is the power, petrochemical, metallurgical, pharmaceutical, and other enterprises in the key power equipment, the safety and reliability of its operation in the production process is very important. And machinery and equipment of the axial rotation of the shaft vibration, axial displacement, and so is the unit operating conditions, the fault diagnosis of state parameters, especially for thrust bearing burned and broken shaft such a failure, analysis of data than analysis of the axial Shaft vibration, displacement data more direct and effective. In order to ensure the safe operation of air compressor, axial force to prevent a catastrophic failure caused a large, steel mills DA1480/0.6 a centrifugal air compressors axial force established on-line detection system, the thrust of this parameter as online , Overrun alarm and stopping the chain of important indicators. Control of the axial force in an appropriate range. In addition, the axial force on the dynamic signal analysis can also be found in some machines, such as air shocks, such as Surge fault.
                    Second, the function of monitoring system
    1, dynamic real-time display of a single axial measurement points of the value or the average.
    2, historical data can be set at the time, the current time, date and alarm values.
    3, can choose to print the instantaneous data or historical data and the corresponding measurement of time.
    4, has an internal clock automatically recorded in the corresponding axial measurement of time, especially gauge the corresponding value of time.
    5, the gauge of memory function, the situation in case of overruns, DCS Shang Sheng-alarm system has been a sound and light alarm signal, when the system returned to normal at the Voice Signal automatically eliminated, and the optical signal has been reported memory, until the elimination of man-made .
    3, axial force on-line monitoring of the test
    1, the air compressor is turned on, the issue of ear-piercing screams, a surge, four exhaust pressure rose to 0.6 Mp (gauge), the take-off safety valve, axial force volatile, and there are no rules step by step Increasing trend, and the sound and light alarm activated in Figure (a) below.
    Analysis after the pipeline unreasonable for the air compressor caused by exhaust electric air compressor check valve normal, anti-surge valve action is also normal, silencers and found Mufflers import protection does not remove the board at the time of installation.
    2, restart air compressor, imports of lead from five percent to 60 percent of a total of 6 s, axial force from 05 t to 7.6 t basically stable, with about 10 s, axial force sound and light alarm activated, the Commissioner of air compressor After the electrical pressure valve, four exhaust pressure from 0.055 Mp rose to 0.2 Mp, axial force to 5.0-5.3 t, Voice Signal automatically eliminated, elimination of artificial light on. Figure (b).

    After the electric air compressor Commissioner to continue to pressure valve to 0.3 Mp, air compressor shaft vibration extremely unstable, vibration gradually increased until the value chain of parking, causing the rotor balancing destruction. Axial force also signals an upward trend. Figure (c) below.
    Analysis of the new manufacturing welding stress in the rotor at the time can not be completely eliminated, have certain residual stress, residual stress will result in residual strain, the residual stress should be more than 80 percent of the light load or no load operation to eliminate the situation, Question of vibration signals and axial force only when pressure has stabilized.
    3, Rotor been installed after the re-balancing drive, air compressor discharge pressure rose to 0.2 Mp operation after 12 hours of the axial shaft vibration and smooth, then gradually pressurized air compressor discharge pressure to 0.52 Mp, a 24-hour operation, everything is normal.
                                   Concluding remarks
    Large group of centrifugal air compressors axial force the introduction of online testing, testing and operation in the effective monitoring of the air compressor stability, the stability of the axial force marks the stability of air compressor, axial force of different changes, Note air compressor, such as a shock, Surge, displacement changes, impeller deformation, impeller tearing, burning bush, bush-fault, such as the emergence of crack. Should stop and timely adjustment