Severe weather conditions in mines and also at open pits affect on the service existence of pump and coal pump units.
High air humidity, in addition to thermal shocks cause alterations in winding resistance of electrical machines and spools of trigger units. Ice plugs exist in hydraulic transport units, plus water supply system at low temperatures in the winter months they might cause breakdowns of weld joints and valves of pipelines. The hydraulic fluid in ground pumps and coal pumps freeze intoxicated by cold, forms a leak-tight crust which can be warmed only by warm water or steam. The deposit generation inside pumps causes additional put on of impellers and seals because of the flow rate increase and solids carry-over. Natural put on is associated with continuous contact of pump unit parts using the contaminated water or hydraulic fluid flow. Major put on is noted in O-rings which separate the pump stages, plus discharge devices. Impellers and seals are exposed towards the finest put on in ground and coal pumps. For this finish, the timely inspection and substitute of worn parts allow maintaining your fundamental parameters of pumps and coal pumps inside the operating section of characteristics and staying away from an urgent situation failure. Such failure, for instance, thrust bearings could cause sharp increase from the axial pressure and motor failure.
A pump unit operator or dispatcher shall control carefully the whole process of water drainage, hydraulic lift or ground pump station when maintaining automated pump stations. All problems within the coal pump, pump and ground pump operation will be recorded inside a special log. For this function, a magazine will be stored within the pump and hydraulic lift chamber or in the earth pump cab. Book or log records would be the important cause for planning scopes and creating relation to various repairs.
A properly built repair system ensures timely charge of pump equipment serviceability for more operation.
Each kind of apparatus (water drainage, hydraulic lift, ground pump) functioning shall possess a schedule of preventive repairs.
The preventive repair system includes the next primary actions:
• inspection from the pump, electric drive and trigger equipment with a maintenance operator throughout the shift acceptance and while operation
• periodical inspection from the pump station with a special repair team
• periodical repair from the pump and coal pump unit transported out directly within the chamber or in the region (routing repair)
• periodical substitute from the pump (coal pump) in the district and central water drainage (hydraulic lift)
• periodical repair water drainage (hydraulic lift) equipment within the central electric shop (CEMS).
The initial system of preventive repairs contains schedules of inter-repair maintenance, in addition to routine repairs and overhauls. Emergency repair describes unscheduled ones.
Routine repair from the pump unit is conducted once in 15 days through the special repair team. The next scope of works is conducted within this situation:
• small parts (discharge rings, pins, sleeves, and cocks) are partly replaced
• the suction and delivery pipelines and pump covers are disconnected and inspected
• the intake valve and mesh are cleaned
• gate valves and appearance valves are replaced
• oil baths or anti-friction bearings are flushed oil, packing are replaced and glands are adjusted
• the impeller is inspected
• pumps, coal pumps or ground pumps are removed from solid precipitations
• worn gaskets are replaced
• the conditions from the front parts of the motor rotor and terminal block are checked
• the insulation resistance and air conditioning from the motor are controlled.
All kinds of routine repair are recorded in logs. A punch list to be the primary document for that unit preparation for overhaul is attracted up according to records. The sheet includes major defects and techniques for his or her removal, along with the listing of needed spares.
Overhaul offers complete restoration of pumps in compliance with technical needs. The pump, ground pump and coal pump is disassembled using all needed auxiliaries (winches, hoists, overhead electric hoists). Possible from the entire unit demounting isn’t excluded.
The overhauled pump performance will be identical to the new pump performance.
Emergency repair is associated with removing problems occurring during accidents or problems which might cause any sort of accident.
Each scheduled repair includes the repair preparation and unit testing after repair.
An urgent situation failure occurrence is described because worn parts were left within the pump throughout the repair or defective parts were installed.
The pump failure is because the irresponsible attitude of maintenance personnel to the responsibilities (for instance, in situation of lubricant absence, excess tightening of bearings).
Regarding the labor content, emergency repair might be comparable to routine repair or overhaul. Therefore, each emergency is attracted up by means of an action that contains detail reasons for the pump failure.
To prevent accidents , relation to repairs will be strictly adopted as well as their quality will be elevated.
Each mining enterprise shall struggle for that repair cost reduction: lessen the repair cost – this can lessen the prime price of the mineral.
For this function the next actions will be transported out:
• reduce the necessity in repairs because of the pump unit maintenance improvement and introduction from the automatic pump duty control
• reduce the repair labor content
• increase relation to pump unit service existence by replacing high-put on parts with more powerful ones made from new man-made materials.
