SEMI-MECHANISATION BY SDLs & LHDs I. Satyanarayana, M.Tech,MBA,MCA Dy. Manager, Project Planning, SCCL, firstname.lastname@example.org, visit at www.slideshare.net/isnindian ISN
PRESENTATION ONSEMI-MECHANISATION BY SDLs & LHDs I. Satyanarayana, M.Tech,MBA,MCA Dy. Manager Project Planning ISN
CHRONOLOGY OF INTRODUCTION OF UG MECHANISATION IN SCCL1956 – Coal Cutting and Coal ploughing1962 – Gathering arm loaders and Shuttle Cars1976 – SDLs (GDK No. 9 Incline)1979 – Roadheaders1980 – LHDs (GDK No. 9 Incline)1983 – Longwall Technology1989 – Blasting Gallery Technology ISN
INTRODUCTION• In order to keep away with the arduous labor of loading coal manually, to avoid exposure of persons at face and improve productivity efforts are made to introduction of intermediate technology and continuous mining systems.• as a result, in India SDLs & LHDs have taken foot forward in intermediate technology. contd… ISN
INTRODUCTION• The Board and pillar method has been predominantly adopted in SCCL and in India for the extraction of coal seams due to shallow depth and good roof conditions.• Although every effort is made to introduce LW method of mining, it is not likely to replace the entire board and pillar method contd… ISN
Cycle of Operations•Drilling•Blasting•Supporting•Coal loading (SDLs & LHDs) ISN
OPERATION OF LHDs and SDLs Method of working The method of development and depillaring with LHDs/SDLs was similar to Conventional development of forming rectangular OR square pillars as per Regulation 99 of Coal Mines Regulations, 1957 and subsequent extraction of pillars by splitting and judiciously reducing it. Coal Preparation Coal preparation for LHD/SDL was done by conventional drilling and blasting.TransportationThe coal carried by LHD/SDL from the face was discharged on to thepony belt conveyor, which was maintained as near to the face aspossible, even though LHD/SDLISN cope with about 100m lead. can
Details of LHD• an electro-hydraulic powered underground mining equipment• used to collect the coal, haul upto the discharge point ofhopper/chain conveyor/belt conveyor located within 100 m fromthe coal face and to dump on it.• 50 HP (811 Model) Motor and 100 HP (912E Mode) Motor•Three forward and three reverse speeds.• The working pressure of hydraulic system is 2200 PSI anddischarge 16 GPM.• The hydraulic tank capacity is 210 ltrs.• Oil is cooled by a radiator and fan run by hydraulic motor.• The power to the machine is fed by a trailing cable 16 m2handled by a cable reeler, which can accommodate 100 m length. ISN
Advantages of LHDs(a) Indigenous and : To save foreign exchange and to availability of spares reduce breakdown hours.(b) Robustness : To withstand difficult conditions.(c ) Compactness : To work in restricted underground space.(d) Reliability and : To enable to resist difficult conditions. susceptibility(e) Adaptability : For easy maintenance.(f) Portability : Easy to move from place to place.(g) Safety : Proper guides and covers. Elect. Protective devices. ISN
SAFETY FEATURES of LHDs1. HEAD LIGHTS2. OPERATOR’S CANOPY3. DUMP VALVE4. PARKING BRAKES & SERVICE BRAKES5. GONG BELL6. AUDIO VISUAL ALARM7. EMERGENCY STOP BUTTON8. DEAD MAN SWITCH9. FLOAT (OIL LEVEL) SWITCH10. TEMPERATURE SWITCH11. CABLE OVERRIDING SWITCH12. PILOT CORE PROTECTION13. PUSH BUTTON STATION14. BRAKE ACCUMULATORS ISN15. FIRE EXTINGUISHERS
Details of LHD ..Contd•The temperature of hydraulic oil is kept well below 65o C.Cycle Time for LHD 811 Model1. Available time per shift - 390 minutes2. Time for trip - 5.7 minutes3. Number of trips per shift for LHD - 654. Output per shift for LHD - 72 tonnes5. OMS - 3.375 tonnes6. Output per drill - 60 tonnes ISN
BEST PRACTICES ..Contd Keeping LHD path clean, dry and flatSmooth and uniform discharge by LHD on the belt conveyorCategorisation of Spares & ensuring availability of fastmoving parts in underground stores.Providing appropriate tools for techniciansAvoiding acute anglesPreshift extention/retreating and maintenance of conveyor beltsPreshift maintenance of LHDsEasily shiftable tail end assemblyReplacing/overhauling Transmission and axles of LHDs (biannualProviding drill machine in each face and spare Gate EndPanels for LHDs Cable VulcanisingTyre and tube repairing and inflation ISN
Code of Practice for Overman: He should inspect the route of LHD/SDL marching priorto marching and take the following precautions: Ensure no obstruction in the way of marching. Check thepresence of W-straps, bolts, chock timber, old pipes andother material that damage to the LHD/SDL and result toother breakdowns. Take necessary precautions to prevent dislodgment ofvertical supports, if any, due to moving trailing cable. Ensure that the persons engaged have taken all necessaryprecautions. Take necessary precautions while crossing track line, pipeline etc. And also avoid rubbing of trailing cable againsthard surfaces and to pillar corners. ISN
OPERATING PROBLEMS• Non-availability of machine• Poor utilization of machine• Lack of Coal preparation• Delay in supporting• Delay in machine tramming• Delay in tub supply or backup transport services (crusher, belts, bunkers etc.,)• Idle time due to shift change hours• Lack of spares availability ISN Contd…….
OPERATING PROBLEMS• Lack of on-hand trained crew• Lack of midlife overhaul of machinery• Lack of maintenance of machinery• Poor working environment• Timely not positioning of supervisors• Poor placement of orders• Unsatisfactory incentive schemes• Untrained mechanized district crew right from supervisor to workmen. ISN
1. Improvement of availability and utilization of machinery – Idle time due to shift change hours can be reduced by implementing overlapping 4 shifts. – Proper maintenance of machinery i.e., strict scheduled maintenance should be followed. – By making availability of coal at max. no of working faces. – Reducing flitting distance of machine. – Timely availability of spares by follow up with firms and placement of RC & departmental contracts. – By introducing sufficient number of mechanized roof bolting machines with rated power pack/ air compressors. – Deployment of trained efficient supporting crew, technicians and operating personnel. ISN
2. Working of full shifts.– Implementation of staggered shifts– Positioning of supervisors in time.– By improving good environmental conditions such are ventilation, supporting, drainage and house keeping.– Keep availability of material for supporting , ducting and spares.– Efficient back up services like pumping, work-shops, coal evacuation system, bunkers etc.,– Proper incentive schemes. ISN– Treating people with due regard.
3. Other recommendations– Introduction of high capacity and cable less LHD’s– Good communication system at all levels.– Intensive monitoring at all levels.– Increasing length of cable by reducing diameter of cable or increasing drum diameter.– Mechanization of face drilling.– Introduction of multi job concept like ‘operator cum mechanic’, ‘coal cutter cum support men’ ISN Contd……
3. Other recommendations– Introduction of equipment maintenance by OEM.– Design of suitable training module.– Out sourcing of non-core activities– Adjusting general shift man power in production and retaining only in statutory requirement.– Explore the workings at suitable gradient.– Avoiding water and slurry condition by proper maintenance of drainage system– Selection of educated and young persons as operation ISN crew.
CONCLUSIONAvailability of coal faces & more yield per blastMaintain less lead (30m)Continuous LoadingExtensions/Retreats & Pre-shift maintenance etcIncrease machine utilizationBetter working conditionsGood discipline, higher morale and well planned actionsTraining ISN