Nirbhay Kumar Sinha

Roll-2013MT0130Branch-Mining Machinery Engg.

ISM Dhanbad

INTRODUCTION :

Continuous miner is a machine used for cutting and loading of coal used in underground Board and Pillar mining operation.

The JOY continuous miner product line has been developed to meet the high productivity requirements of today's underground mining industry.

Types available in the market : -

The continuous miner product range is segmented by mining height requirements into three machine classes for low, medium and high-seam applications.

14CM Series Continuous Miners 12CM Series Continuous Miners 12HM Series Continuous Miners

Main parts of a Continuous Miner : - Cutter Gathering head Conveyor Traction Dust collector Manifold Hydraulics Electrical Circuits

CONTINUOUS MINER (MAIN PARTS)

CUTTING PEAKS

CUTTER DRUM

GATHERING ARM

CHAIN CONVEYOR

HYDRAULIC SHEARCYLINDER

BOOM

TRACTION

Specification : -

JOY 12CM15 is a high capacity, totally remote controlled CM designed for medium to high coal seam applications. The machine has

Cutter head drum Diameter - 1.12m Cutting Width - 3.3m Max cutting height - 4.6m Conveyor width - 0.76m

with 2.41m/s speed

Specification : - CM is equipped with 2 cutter motors, with

standard clutch protected, AC induction Motors (170KW) mounted parallel to centreline of boom frame.

Each cutter motor connects to the gearing of gear case using an internal torque shafts.

2 gathering head motors (AC) of 40KW 2 traction motors (DC) of 26KW 1 pump motor of 52KW; 1 dust collector fan motor 19KW. Total Weight of CM = 58 tonns(58376Kg)

Cutter Drum: -Left Cutter Drum

Centre Cutter Drum

Right Cutter Drum

Cutter Head

The cutter head may be of borer type, Oscillating head type and Horizontal drum type.

The majority of the continuous miners currently in operation are of horizontal drum type on which block are mounted in the form of a scrolls, carrying peak boxes.

The boxes are welded or bolted to the drum.

There are 2 cutter motor one in each side of the machine.AC induction, 1500 rpm170KW each.

Cutter Motor.

Tungsten carbide teeth used for cutting.Replaced when broken and treated as consumables.Peaks consists of two materials, tungsten carbide and cobalt.

PEAK (TEETH)

The most important physical properties of the cemented carbide are hardness and toughness.The value of both these properties can be varied by the presence of cobalt.

Variation of Hardness/Toughness with % of cobalt

% of Cobalt

The most important physical properties of the cemented carbide are hardness and toughness.The value of both these properties can be varied by the presence of cobalt.

Variation of Hardness/Toughness with % of cobalt

% of Cobalt

Angle formed by a line drawn longitudinally through the shank and the point of peak and the line forming the radius of the peak point.The sum of the back and front clearance angles will be equal to 30 degree.

Angle 0f Attack & Clearance Angle of a PEAK

Angle of AttackFront Clearance Angle

Back Clearance Angle

Angle of Attack

5 Ton Hydraulic Jack.

Cutter boom.

Cutter Boom

Shear Cylinders

Gathering Head : -

Centrifugal Loading Arm (CLA)

These CLA’s rotate in opposite direction to each other.

There are 2 Gathering motor one in each side of the machine.AC induction40KW each.

Gathering Motor.

Gathering head is raised and lowered by a single acting lift cylinder on each side of the machine.

Gathering Head Lift Cylinder.

Conveyor : -

Foot Shaft Flight Bar

Foot shaft is a shaft with a (4 toothed) sprocket, over which the flight bar chain sits, whose construction is responsible for movement

of coal

The movement of flight bar is >100mm from centre ----chain should be tightened.The movement of flight bar is <50mm from centre ----chain should be loosened.

Conveyor Chain Adjustment:

Conveyor Chain Adjustment:

A loose chain may jam, a tight chain may become overloaded causing high temperature in the drive or foot shaft leading to excessive wear. So, in order to address this issue a tension adjustment arrangement is made by incorporating a spring at the end of the take up cylinder to the side of swing conveyor.

 

Traction :-

Traction :-

Incorporates Crawler chain, brakes, Traction Motor, Traction planetary and Traction Reducer.

Traction motors are of 26KW of DC. Traction motors are connected with

reducer and the sun and planetary arrangement helps the crawler chain to move which sits on the sprocket connected with sun shaft.

Traction :-

It is equipped with spring applied, hydraulically- released traction brakes, which are normally applied.

Springs inside brake assembly push a piston against brake disks results in stoppage.

These are released when hydraulic pressure is applied to compress the springs and retract the piston.

This uses a slurry pump – motor to remove slurry from dust collector sump. It is located in the dust collector fan compartment.

Dust Collector.

Electrical System:

The input power to the CM is a 3 phase 950v AC (though 1100v or 1.1KV is the specified value).

Traction motors are controlled with a dual 6SCR drive system.

A control Transformer drops the line voltage to 110v AC for the control circuit, and 12 volts for the head light circuit.

CONCLUSION:-

In this world where nowadays where technology matters CM plays an important role and is a kind of boon in the field of mining industries, which has not only reduce the manpower and accidental records but has also increased the coal production as compared to the conventional methods.

REFERENCES:-

Wikipedia Google Search Google Image Class Notes (Ajit Kumar Sir)

THANKYOU