The Blast hole drills (BHD) deployed at Neyveliare of ingersoll-Rand make. These drills are basically hydraulicdrills. For the various operations of the drill, direction controlvalves (DCV) operated with 24-voit DC coil was used. Butunfortunately in all the drills, the direction control valves startedgiving frequent troubles due to accumulation and ingress of duston the ports of the solenoid coils. Frequent cleaning of directioncontrol valves became necessary leading to non-availability ofthe machine bey6nd the maintenance hours leading toproduction losses. The solenoid operated DCVs, were replacedby sandwich type mobile control valves for the hydraulicactuator operations. Though the mechanically operated valveswhich have replaced the mobile control valves are more troublefree, they are cumbersome to use and are a journey back in time.This paper looks into the factors that led to such a decision andcompares both types of valves and the performance of the drillafter the introduction of the mobile control valves. Finally,based on a study of drill operators' efficiency by the authorsbefore and after the conversion, it is being suggested here whyand how solenoid valves can be reintroduced. Also a glimpse onhow modem maintenance practices and computer-based troubleshooting can help overcome the earlier problems is also suggested.
展开▼
