The mill roller size starts from (305X305 ) to (504 X 762) The rollers are of coarse grain cast iron having hardness 180-210 BHN. The composition of the shell material shall confirm to IS: and shall be
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Total carbon
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-
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3.20 to 3.6 percent
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Manganese
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-
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2.2 to 3.2 percent
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|
Silicon
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-
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1.2 to 2.2 percent
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Phosphorus
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-
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0.5 percent max
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Sulphur
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-
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0.15 percent Max
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The cast iron shell shall be hot shrunk on forged steel shaft of 40 C8 quality conforming to IS: 1570 or equivalent having a minimum tensile strength of 58 kg/mm2. All the shaft is having square ends,. Top roller shall be fitted with stationary flanges and juice rings in two halves. The bottom roller is providing with juice rings and removable guards to prevent entry of juice into the bearings. The cast steel crown pinions shall have minimum 380mm face width and conform to IS: 2708 grade 3 with well-dressed property profiled moulded teeth, keyed to roller shaft and suitable mild steel guards and troughs.
The headstock and crown pinion are designing to accommodate rollers of outside dia.varying according to a size of mill The fabricated headstocks is a boltless type. Removable hard steel /cast steel /gunmetal /fibre wearing plates on feed side as well as discharge side and with a lubricating arrangement between top roller bearings and wearing plates shall be provided. The top and side are of cast steel as per IS: 1030 grade 280/ 520 W and shall be securely locked in position for quick assembly stainless steel, a strip of suitable thickness is providing in the roller bearing face of the headstock. The eccentricity between top roller bearing centre and hydraulic cap centre is keeping suitably towards the feed side of the headstock, except in case of inclined headstocks.
The bearings are of cast steel with gunmetal /white metal Gr.6 as per IS: 25 1979 lined and with water cooling arrangement. The side roller bearing is of cast steel housing with renewable gunmetal liner as per IS 318 or renewable steel liner with white metal lining as per IS: 25. The housing is having water cooling arrangement.