TTPS Operation Circle MPM II Unit V Overhauling of mill, gear box, under bowl, mill outlets, classifier assembly etc., in Mills 5A to 5F during forthcoming overhaul

Charges for draining the oil from mill gear box, cleaning the gear box, worm wheel, worm shaft with neat cloth, arresting of oil leaks and refilling the gear box with old or new oil as directed by the Engineer –in charge, including transportation of material from and to stores and cost of consumables.

Charges for Dismantling of upper skirt assembly, lower skirt assembly, Mechanical face seal assembly, dust guard and blue matching of seal runner, renewal of seal (bronze), air seal, dismantling of Mill bottom cover, upper bearing housing cover, oil seals etc., Complete overhauling, assembling back the lower skirt assembly, scrapper assembly and arresting the oil leakages in the return line and also spillage’s at the rear side of gearbox to prevent Mill fire including cleaning and tapping the threaded holes.

Charges for dismantling the gear coupling bolts, gear coupling (worm shaft only), distance piece, unscrewing the worm shaft extension cover bolts and bearing housing cover bolts, removing the worm shaft extension cover, lowering to ground floor, releasing the worm shaft assembly from its position and assemblies providing back the overhauled worm shaft assembly in the gear box and fitting back the worm shaft extension cover, bolting and tightening the bolts to the required torque level and assembling back the gear coupling bolts, distance piece etc.

Charges for checking the bearing clearance after dismantling the thrust bearing and radial bearing housing covers, removing the bushes, springs etc. thoroughly cleaning the bearing housings and other components inspecting the thrust bearings, resetting the axial clearance by reducing the thickness of shims in the thrust bearing housing cover, providing of new shims and by trial method adjusting the clearance to 0.10 mm to 0.15 mm. Assembling back the thrust and radial bearing housing properly and renewing the gland studs and gland packing in the worm shaft assembly.

Charges for changing the worm shaft thrust bearing after gas heating and releasing the old bearings from the worm shaft, heating the new bearing in oil bath and providing the new bearing in the worm shaft in proper position.

Charges for renewing radial bearing in the worm shaft after gas heating and releasing the old bearing and providing new bearing in the worm shaft after heating the bearing in oil bath.

Charges for removing (by gas cutting) the eroded spout segments liner from the inner cone and reconditioned the spout segments and refixing the spout segments liner without gap as per the direction of Engineer in charge. This includes the transportation of materials from and to stores and consumables.

Charges for dismantling the wornout spool pipe and MPO (each 4 Nos.) after supporting the relevant coal pipes firmly and disconnecting the victaulic coupling, air line and other accessories and replacing of liner, old /new victaulic coupling gaskets, replacement or inverting the orifice and re-fixing MPO, MDV or spool pipes as per the direction of Engineer in charge. The work includes lead, lift of materials from `0’ meter and devolution of scraps to stores and cost of consumables such as cutting gas, welding electrodes etc.,

Dismantling of worn out classifier assembly, inspection of deflector blade, cleaning, replacing of worn out deflector blade components renewal and assembling of new classifier assembly with its links. The overhauled classifier assembly was checked from 0 to 6 positions and ensured that the deflector blades, links move correspondingly to its position without any malfunction.

Charges for dismantling the centre feed pipe from mill top to transition piece lowering down and placing it in the specified area. Cutting the wornout portion and reconditioning with new/old pipe aligning with the mill and fitting in the correct position as per the direction of Engineer incharge, necessary scaffolding platform and support to be provided by the contractor. This includes consumables and transport of materials from stores and devolution of scrap to stores.