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Radial Compressors and Axial-flow Compressors
MEASUREMENT OF VIBRATION AND ASSESSMENT OF TECHNICAL CONDITION OF RADIAL AND AXIAL-FLOW COMPRESSORS
The measurement is limited to that of physical quantity sets which can be used to define and evaluate unambiguously the dynamic condition of the whole compressing unit with the drive, clutch and gear.
Such measure is conducted in order to:
- Locate the sources of vibrations and determine their causes,
- Assess the vibration degree: current condition compared to the history of the machine,
- Collect data to make a complete analysis of the vibration state: current condition compared to the history of the machine,
- Interpret the vibration state observed: current condition compared to the history of the machine,
- Make a diagnosis regarding the technical state of the turbo set: current condition compared to the history of the machine,
- Make a forecast about the future technical state: current condition compared to the history of the machine,
- Prepare data concerning the time-span necessary for the repair and its scope.
- Determine the time necessary for the repair and its scope on the basis of the measurement of vibration.
The repair procedure can be planned according to the actual technical condition of the compressor’s unit. The additional advantage of this approach is that it is possible to obtain proper spare parts beforehand. As a result, the time necessary for the repair can be reduced to a minimum.
Type and Scope of Measurement:
We conduct measurements on machine sets which are operating or disabled.
Measurement of an operating turbine set’s vibrations is conducted with:
- a monitoring unit mounted permanently: the so-called turbine set monitoring system,
- sensors of a stationary monitoring system mounted on the turbine set,
- a measuring system installed by us for a longer period of time,
- a measuring system installed by us for a period during which the measurement is carried out,
- a portable measuring apparatus.
In each of the above cases, if necessary, the measuring system can be supplemented with sensors essential for obtaining the best description of the compressor set’s technical condition.
The scope of measurement we conduct depends on requirements, objectives and a technical problems occurring while the turbine set is operating.
Depending on the scope of the measurement, we are able to indicate and inspect the following basic faults of the compressor set:
- Flaws of the rotating system’s balance,
- Flaws of alignment,
- Seizures in seals,
- Looseness in bearing supports,
- Defect of the arrangement of bearing supports,
- Misalignment of the rotor in the electric engine’s stator,
- Axial displacement of the rotor in relation to the engine’s stator,
- Misalignment of the compressor’s rotor with the engine’s rotor, gear and clutch.
Apart from that, we carry out measurement geared to wards:
- Preparing the scope of repair work: selection of elements which must be inspected in the course of the repair,
- Assessing the vibration condition after the completion of the repair,
- Determining the frequency of free vibration of elements (e.g. blade, blade rims, reducers’ covers, elements of bearings etc.) and machines’ units (e.g. pipelines, gates, support mechanism etc.)
- Measuring and assessing the influence of a flowing medium on the vibration condition of the compressing unit (effect of the input dynamics),
- Assessing the influence of electromagnetic inputs on the dynamic state of the unit,
- Searching for causes of instability of the rotating system’s motion
- Eliminating all unfavourable and untypical phenomena occurring in the course of units operations.
We indicate loosenings or any possibility of looseness in the blade disk or clutch plate mounting on the shaft of the rotor. Measurement is carried out when the rotor is disabled, for example, during a repair of the unit. For this purpose, we use a method developed by the VIBROPOMIAR Company on the basis of modal analysis.
Measurement is geared to wards defining ranges of compressor sets’ actual critical velocities
We also determine the frequencies of free vibration of the compressor’s elements. Thanks to this, it is possible to protect the inspected elements against resonant vibration. Such measurement is aimed at improving the safety of operation.
The VIBROPOMIAR Company also maintains a measuring team which responds to emergencies. It conducts limited measurement consisting of the evaluation of the rotating system’s vibration condition. This measurement serves the purpose of assessing fitness of a rotating system for further operation, making it possible to evaluate its technical condition .
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