seminer predictive maintanance

7/30/2019 Seminer Predictive Maintanance

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WELCOME


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SEMINAR ON

PREDICTIVE MAINTANANCE USING VIBRATIONANALYSIS

PRESENTED BY: SAMIR KUMARBOSEDEPT. MECHANICAL ENGG.

ROLL NO: 0910300705REGISTRATION NO: 091030110327


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-:

Vibration monitoring:

Thermography.

Tribology.(lubricating oil analysis, spectrographic analysis,

wear particle analysis.)

Ultrasonic.(leak detection, or material testing.)


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Vibration monitoring is the most reliable method of

assessing the overall health of a rotor system.

Spectral analysis of vibrations has been used in rotating

machines fault diagnosis for decades.

When a mechanical part of the machine either wears or

breaks up, a frequency component in the spectrum will

change.


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Misalignment of couplings, bearings and gears.

Unbalance of rotating components .

Looseness .

Gear wear . Rubbing .

Electrical problems (unbalance magnetic forces) in motors.

Resonance.


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Repeating Forces:-

The term repeating forces refers to those unbalanced

forces that occur over and over again within a machine to

create movement. Repeating forces in machines are

caused mostly by the rotation of imbalanced, misaligned,

worn or improperly driven machine components.

Looseness:-

Machine parts that are loose may cause the machine to

vibrate. If parts become loose, vibration that normally is

acceptable may become excessive && damaging.


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Resonance:-

Most machines have at least one natural frequency of

vibration, commonly referred to as natural oscillation rate.

Although a repeating force may be small and result from

the operation of a sound machine component, such a

repeating force potentially may match the machines

natural oscillation rate and create resonance.

Frequency:-

A machine component typically vibrates at more than one

frequency. This occurs because a variety of forces generally

act upon a machine component during operation.


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A v i b r a t i o n s i g n a l i s p r e s e n t e d a s a s i n u s o i d a l w a v e

f o r m w i t h a l l f r e q u e n c i e s a n d a m p l i t u d e s c o m b i n i n g

t o g i v e o n e o v e r a l l s i g n a l .


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By applying the FFT (Fast Fourier Transform) algorithm

to a Time Domain signal, it is converted to theFrequency Domain.

In the Frequency Domain, each individual amplitude

and frequency point are displayed here.


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Baseline Data:-

Baseline data sets should be acquired for each machine when

the machine is installed.

Reset After Maintenance:-

The baseline data set must be updated each time the machine is

repaired, rebuilt, or major maintenance is performed.

Proper Identification:-

Each reference or baseline data set must be clearly and

completely identified.


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Acceptance testing:-

It performed at the factory & immediately after

installation can be used to ensure that new equipment

performs at optimum efficiency & expected life-cycle

cost.


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Noise control:-

Vibration analysis can be used to isolate the sourceof unwanted noise generated by plant equipment.

Leak Detections:-

A variation of vibration monitoring and analysis can

be used to detect leakage and isolate its source.


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Recommendations are following:-

Measurement methods and parameters.

Transducer selection, location, and attachment.

Data collection.

Machine operating conditions.

Vibration monitoring systems.

signal conditioning systems.

Interfaces with data processing systems.


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Overall Vibration

Steady State

Synchronous


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Outputs the sum of all vibration measured within

a specified frequency range.

Used as an initial alarm type survey, whereby if

the overall indication is above a specified value,

a more detailed survey is performed to identify

the possible cause.


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Used to measure v ibrat ion at a constant

engine/component operat ional

f requency.

Used to determine the speed / f requency

at which balancing shou ld be per formed.


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Ut i l i zes a tachometer s igna l & a f i l te r to t rack v ib rat ion of a spec i f ic ro to r o r shaf t .

Used to determine the ampl i tude of an

imbalance condi t ion.


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Sensor Selection:-

The first consideration is manufacturers recommendations. Ifnone exist, then:

Frequency Range.

Environmental conditions.

Sensor:-

A transducer that converts mechanical motion into

electronic signals. Three categories: Displacement.

Velocity.

acceleration.


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Displacement:- Measures the distance an object is

moving from a reference position. This distance is

typically reported in mils.

Velocity:- Measures the rate of change of position an

object is moving, and is commonly reported in Inches

Per Second (IPS).Best suited to measure vibrations

between ~ 10 Hz and 1000 Hz, or 600 to 6000 RPM.

Accelerometer:- Measures the rate of change of

velocity per time period. Acceleration is reported in

Gs. Most effective frequency range for an

accelerometer is above 1000 Hz, or 6000 RPM.


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Increased component operational life/availability.

Allows for pre-emptive corrective actions.

Decrease in equipment or process downtime.

Decrease in costs for parts and labour.

Better product quality.

Improved worker and environmental safety.

Energy savings.


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Increased investment in diagnostic equipment.

Increased investment in staff training.

DISADVANTAGES:-


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THANK YOU

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