Friday, September 17, 2010

CS 2: Changing bolt and nut

Changing bolt and nut to CS 2 had been carried out twice. Total replaced bolt and nut are 180 pcs todate. (equivalent to 45 bars). It is estimated that after 2 more times checking and bolt & nut replacement, all 100 bars will get new bolt and nuts. Replacement is deemed necessary as bolt and nuts had started to give way under current working condition. Previous bolt and nuts were in use started from 1st September 2009. Upon observation, it is best to replace bolt and nut MS 1/2" x 1 1/2" after 6 months or up to 9 months to ensure no CS breakdown due to broken bolt and nut.
Earlier there had been an idea to use HT bolt and nut in place of existing MS bolt and nut, but after considering nature of previous breakdowns inside CS here, it is best to still use same bolt and nut's material. Usage of HT bolt and nut may cause more breakdown as bolt and nut is no longer the weakest point... it may cause either bracket if not chain to break.

Wednesday, September 15, 2010

CS: An experience

CS mill, its the new look of JPOM. Working wise had been easier, as the mill is now operated almost fully automated up front. No SCADA system in place, but hard wire automation is more than sufficient. Key for smooth operation for CS is monitoring of control room and maintenance of CS chain. As practiced, both CS that we have here were under checking and maintenance every week. Both sterilizers require checking once a week without fail. To those with experience running CS, this is the most important time during the week. The 'quality time' spent during this maintenance period will determine what sort of week that we are going to enjoy next... will it be smooth, ruthless and efficient... or tiring, sleepless nights... its our choice...
Just to update, elongation had been too much until there is no room for adjustment left. We had cut 3 links at both side of CS no. 1. The CS now is shorter by 2 links on both side of chains. LH side is longer by 50mm compared to RH side. The cutting took place on Tuesday 14th Sept 2010. Next will be changing whole set of bolt and nuts that keeping bar to chain, which planned on 16th September 2010 during daytime. 400 pieces of MS bolt and nut is required. Previous changes at sterilizer no. 2 took us from 7.30am to 11.00am to replace bolts and nuts that hold 18 bars @ 18 x 4 bolt & nuts. Only one location used as location to do changes. This time around it will be on both end of sterilizer, so more bars is expected to get new bolt and nut replacement.