Cement and Energy

Table 1 Modernisation of facilities in various parts of the plant Date Work carried out Specific power saving kWh/t cement 1988-89 Cement mill: Installation of high-efficiency Sepax dynamic separator for converting the mill to 2.5-3.0 closed circuit (Fig. 2). 1990-91 Raw mill: Installation of high efficiency dynamic separator. 3.0 1990-91 Calciner: Modification in calciner by increasing its height 1.2-2.0 1990-91 Conveyors : Replacement of pneumatic conveying of cement by mechanical conveying (belt 3.0-4.0 conveyor and bucket elevator). 1990-91 Coal mill: Installation of high efficiency dynamic separator (Fig. 3). 1.0 1991-92 Raw mill fan :Installation of SPRs for speed control. 2.0 1991-92 Coal handling : Installation of stacker for stacking and blending the raw coal which had reduced - variation in coal quality to± 5% in the coal ash (designed and fabricated by Shree Cement team). 1992-93 Kiln feed : Replacement of pneumatic conveying of raw meal by mechanical bucket elevator for 1.75-2.0 feeding the kiln. 1992-93 Prelleater fan : Installation of SPRs for speed control 1.50 1993-94 Expert System : Installation of expert system for kiln, cooler and cement mill. - 1994-95 Raw meal conveyor : Replacement of pneumatic system of transporting raw meal to CF silo by 2.0 bucket elevator. 1994-95 Sampling : Incorporation of on line auto bulk sampler (designed and fabricated by Shree Cement - engi neers) prior to limestone stock pile, which had reduced variati.on in CC to± 5%. 1994-95 Prelzeater : Replacement of conventional twin cyclones of first stage of preheater by indigenously 1.50 designed LP twin cyclones. 1995-96 Roller Mill : Installation of external material recirculation system across vertical roller mill. 0.5-0.75 1995-96 Raw Mill: On-line blending control installed. - - 1995-96 Grate cooler: Retrofitting of fKN-KIDS system of plates in part of first compartment of grate cooler. 0.50 Dust cyclones : Replacement of multi cyclones by ESP for collection of clinker dust from cooler Included in grate exhaust air. cooler Cooler fans : Replacement of cooler fans by high efficiency fans including replacement of butterfly - damper by radial vane type dampers. 1995-96 Quarry management: Installation of computer aided mine planning system for optimum utilisation - of limestone deposit. 1996-97 Preheater: Installation of a booster fan in parallel with existing preheater fan (designed and built by - Shree Cement engineers). 1996-97 Dust collection: Increasing cement mill venting capacity and dust collector area. - Cement mill : Replacement of blind liners of Combidan diaphragm by slotted liners for increasing 1.50 diaphragm opening area from 1.388 to 1.713 m 2 and optimisation of grinding media loading in each chamber of the mill. Calciner : Increase in height from 17.9 to 19.1 m which has correspondingly increased the height of cylindrical portion of IV cyclone (lowest cyclone) by 1.2 m Incorporation of hanging type of immersion tube in stage £V cyclone. lncreasin~the area of kiln riser duct connecting to in-line calciner from 5.76 m 2 to 7.22 m (21.92%). Increasing the internal diameter of down pipes of Cyclone three and four. ' Roller mill : Incorporation of newly fabricated cage rotor in Atox Vertical Roller Mill in place of old worn out cage rotor. 9