IN-SITU DYNAMIC BALANCING

IN-SITU DYNAMIC BALANCING

Rotating unbalance is the uneven distribution of mass around an axis of rotation. A rotating mass, or rotor, is said to be out of balance when its center of mass (inertia axis) is out of alignment with the center of rotation (geometric axis). Unbalance causes a moment which gives the rotor a wobbling movement characteristic of vibration of rotating structures.

Unbalance creates the following effects: • Vibration
• Noise
• Decreased life of Bearings
• Increased Maintenance
• Unsafe work conditions

What is In-situ Balancing?

It is a process of analyzing and detecting Unbalance of a Rotor with a help of a Vibration analyzer. Through scientific calculation, the Unbalance spot in a rotor is identified and an equal amount of correction mass is added at the opposite side of the rotor to minimize the Unbalance force. The entire process is carried out without dismantling the rotor from its original assembly in actual Site conditions. Hence significant reduction in machine downtime is achieved and also cost involved in sending the rotor to OEM’s Work shop is eliminated.

Benefits of In-situ Dynamic Balancing.

• No need to send the rotor to OEM’s Workshop for balancing and thereby significant reduction in machine down time is achieved.
• Cost of Labour involved in dismantling the rotor from original assembly is eliminated – thereby cost saving.
• Increases the life of machine parts and bearing – Hence reduced maintenance spare parts.
• Avoids catastrophic failures.

TURBO MACHINERY – DYNAMIC BALANCING



Unlike rigid rotors, performing In-situ dynamic balancing of high speed Flexible Turbine rotors requires special skill and knowledge in understanding the machine dynamics and critical speed modes. Huge fuel cost is involved, for every Trial run taken during balancing of high capacity T.G. sets. Hence the entire balancing operation has to be completed within “MINIMUM NUMBER OF TRIALS”. The balancing trial weights and balancing Planes have to be chosen judiciously with utmost care.

ALTHUNAYAN Specialists have rich field experience of In-situ dynamic balancing of Turbo Generators up to 600 MW. We have to consider many additional information other than FFT Spectrum and Time Waveforms. We have to utilize advance analytical plots like Polar Plots, Shaft Centre Line, Bode Plots, Orbit plots etc. Our Experts have hands on experience of dynamically balancing Turbo Machinery rotors of different OEM’s like SIEMENS, ALSTOM, GE, BHEL, HTC, DONGFONG etc.. We have carried out hundreds of Turbine balancing activities and have proven record of appreciation for solving complex dynamic balancing of high speed flexible rotors within a shortest possible time.

In-situ dynamic balancing is being performed by DVC Experts for the following rotors:
• Turbines
• Generators
• Hydro Generators
• Motors
• Fans
• Cooling Tower Fans


ALTHUNAYAN specialists after successful Multi Plane Balancing of 108 MW Gas Turbine – GTG UNIT # 8, at GTPS – URAN, Mumbai, India.