Reconditioning of O-Sepa Separator rotor cage wheel

History of separators in the cement industry:

• These are also called cage separator or high efficiency separator.
• These separators were developed from beginning of the eighties (O Sepa from Onoda Cement) .
• At the second generation, the air flow required for the separation is produced by an external fan. And the separator material was carried out mechanically by means of suitable continuous conveyors.
• Fines are conveyed by air in external cyclones or directly to a bag filter.
• In the third generation separator, the main separating device is cylindrically rotor. The rotor is like a cage composed of blades closely spaced.
• The rotor is operated by a variable speed drive.
• The rotor speed determines swirl in the classifying zone and therefore the classification is done.

• Problem : Wear and breakage on spokes, base plate and blade
• Wear mechanism : Severe erosion
• Output   size of particle : 0.1 to 250 microns
• Application : Dynamic loading and metal to metal contact

• Area of installation : Cement Mill
• Location : After cement mill and before cement silo
• Speed : Max. 400 RPM
• Weight : 4500 kg
• Material handled : Cement
• Earlier solution : OEM supplied rotor cage
• WRTPL Solution : Reconditioning of Rotor cage with XAR 500E and carrying out DP/UT test and NDT test with 1 year warranty with enhanced service life.

Scope of work :

• Removal of worn out blades and measure their dimensions and mark  their position in rotor cage.
• Fixing of new rotor blade with XAR 500E, through the cross section with super surface  finish resulting in excellent flow ability.
• Removal of worn out spokes and measure their dimensions and mark  their position in rotor cage.
• Fixing of new spokes with XAR 500E from shaft to cross section with super  surface finish.
• Removal of worn out base plate brackets and measure their dimension and mark their position in rotor cage.
• Fixing of new base plate brackets with XAR 500E from shaft to cross section with super  surface finish.
• To maintain the good quality weld joint and no weld overlay undulation,  hence turbulence can be estimated.
• DP/UT test to  be carried out to ensure crack free surface.
• To do NDT test at all joints for crack and welding flows & rectification if required .
• To do machining of rotor to the dimensional tolerance as per drawing.
• Rotor N-2500 shall be statically balance and dynamically balanced.

Economic potential :

• Average potential for single rotor reconditioning : 11-12 lakhs

Life Comparison :

• Performance before WRTPL repair : 1.5 year
• Performance after WRTPL  repair : 2 years

Key benefits due to reconditioning of O-separator rotar cage wheel:

• Above case study addresses the concern of top management about reclamation of key spares rather then buying new. This approach is economical and technically superior for the society.
• The solution in terms of repair and reclamation aware society to adapt better metallurgical upgrades and innovative processes to improve the availability of the plant and machinery.
• Overall, this thereby reduces the downtime losses and operational costs resulting into absolute improvement of the bottom line for the organization.