dear experts,
we are having loshe mill LM26-3 for coal grinding, now we want to grind pet coke from this mill with a residue of 2% at 90 mic mesh. what changes we have to do or is it possible to reduce the table speed and get the desired fineness and what is the optimum speed pl. write
Dear
There is no problem to grind pet coke in LM . If you send me your operating data and design data like fan flow, nozzle area, mill o/l operating temp , dp , HGI of pet coke and grinding pressure with N2 pressure in accumulaor .
Speed reduction of table can not improve grinding( holding good bed layer of pet coke). better reduced the nozzle velocity of gas with reduction of op. o/l temp around 75 oC and reduced operating dp. set point 20% present with reduced op. grinding pressure 10 %.
GK SHARMA
How much Mill output you have achived in petcoke compare to caol grinding
What Mr. GK Sharma has replied is vey correct.
1. Gradually increase the Grinding pressure to the maximum design level.2. Nitorgen Presure of accumulator also to be increased as per the Mill supplier guide line. 3. Gradually increae the water spray on the Mill table from 1 Cubic Meter to 3 Cubic meter. 4. Reduction of Mill table speed upto 10% will help Pet coke to sustain on the table. 5. Reduce Coal Mill fan speed by 10 to 12%. 6. To maintain the Pet coke residue 1.5 to 2% on 90 Micron sieve, it almost 40 to 50% Production loss is oberved and subsequently power consumption also will increase. Hard Grove Index (HGI) is less than 38 will further reduce the production. Damring height may reduce to minimum level. I think, Mill optimization can be done on the base of trial. Mill outlet temperature also can increase up to 75 to 78 C, it will help to reduce the Mill main drive load.
As per my experience in Pfeffier Mill, Grinding Pressure may increased up to 150 Bar, and accumulator pressure can increase up to 65 to 70 Bar. Mill table speed 92% and Mill Fan speed is 85 to 88% 35 tph capacity Mill production fall down to 20 to 22 tph and Product residue is 1.5% on 90 Micro sieve.