5-2. High-Speed Dynamic Balancing of Turbine Rotors
Specialized Overhaul of Turbine Rotors
1. Journal and Main Shaft:
Inspect journals for corrosion, cracks, and damage. Measure journal runout and concentricity. For journal scoring or wear, perform cold welding repair using electrical discharge deposition welding technology. After repair, machine the journal to meet design specifications.
2. Sandblasting for Scale Removal:
High-velocity abrasive blasting effectively removes rust, scale, deposits, and other contaminants from the rotor surface, restoring the metal's original finish. Focus on cleaning the impeller, blades, and blade roots.
3. Rotor Blade Replacement:
Replace the entire blade stage if severe wear affects all blades or if a few blades in a specific stage are damaged. After replacement, machine the blades to design specifications and perform high-speed dynamic balancing.
4. Blade and Impeller Inspection:
Focus on inspecting crack-prone areas such as rivet heads, areas around tie holes, transitions from the working section to the root, inlet/outlet edges, root cross-section transitions, and rivet holes. Typically employ non-destructive testing (NDT) methods (ultrasonic, dye penetrant, or magnetic particle inspection) to check for issues like tie weld separation or blade fractures.
5. Rotor dynamic balancing is a process that controls residual unbalance within permissible limits by adding or removing counterweights on two balancing surfaces. Its core objective is to eliminate lateral vibration and dynamic loads caused by centrifugal forces and centrifugal couples, thereby enhancing equipment operational stability and service life.
5.1 High-speed dynamic balancing is performed at the turbine's actual operating speed. By measuring vibration and phase at real operating speed, it precisely corrects imbalance caused by elastic deformation.
5.2 Low-speed dynamic balancing is performed when the turbine rotor's support conditions on the balancing machine approximate those of the field machine. The rotor only requires balancing correction at the balancing speed (typically around 20% of the operating speed) by selecting any two plane surfaces perpendicular to the shaft axis for alignment.
Preceding page
Service Items
Get ln Touch Now
Need Assistance? We're Here To Help!