ball mill

The principle and structure description:

1, the mill works

Synchronous motor by a pneumatic clutch, a pinion gear, the large gear driven at a constant speed rotation of the rotary unit, the rotary portion of the cylinder body of grinding media balls under the effect of centrifugal force and frictional force, is raised to a certain height, was spilled off state movement, Material from the feed inlet into the mill at ball impact and abrasive and grinding, grinding minerals from the overflow spout, after screening, qualified product size discharged by the screen, a small amount of material from the big screen Last drain, complete the grinding operation.

 

2, the main components of a ball mill

Feeding part, feed department, main bearing portion, the body portion, discharging part, Transmission Division, Department of Basic, slow gear, jet lubrication device, lifting device, high-pressure pipeline and lubricants and lubrication station master motors, electrical control systems, pneumatic clutch and the gas system, couplings and safety enclosures.

 

3, the structural characteristics of the mill

3.1 feed block

According grinding mill feed selection process, using the feed chute or combined feeding mode.

3.2 feed Ministry

Feed section includes a feed screw barrel, feed and end cap liner and so on. According to the material type design spiral tube structure, tapered seal spiral tube structure, improve the feed material level, to prevent the accumulation of material in the spiral tube grinding process requirements; feed cover to prevent excessive wear and tear, into laying liner material inside cover, liner with impact sclerosis, wear resistant properties.

3.3 tubular section

Barrel is the main component of the ball mill, comprises a barrel, the inner liner and the like. To prevent excessive wear of the cylinder, the cylinder internal laying liner, liner bolted. Rubber pad between the liner and the cylinder, which can effectively cushion the impact of the steel rod of the cylinder, and the cylinder wall liner and make a more snug fit. The selected cylinder liner material has good impact hardened, wear resistant properties.

3.4 feed Ministry

Discharging portion includes a discharge end caps, end liner, spiral tube and discharge sieve. According to the characteristics of the mill discharge, the discharge portion is provided in the overflow discharge spiral tube, so that qualified fine material discharge overflow, too coarse material from the feed screw return cylinder regrinding.

3.5 main bearing section

Using static and dynamic pressure bearing section bearings can be achieved hydrostatic jacking, dynamic pressure operation. Before the mill is started or stopped before the mill starts high-pressure pumps, high-pressure oil into the bush, so that the oil film between the bearing and the journal, hydrostatic jacking; normal operation after the mill, high pressure pump to stop relying on continuous fed into the Low oil to achieve hydrodynamic lubrication. Main bearing by bearing, bearing, bearing cap and cooling system, etc., are all closed circular 120 ° double rocker self-aligning bearings.

3.6 transmission parts

Transmission is by the size of the gear mill consisting of open gears, adapted mill low speed, heavy, continuous characteristics. Where the main motor with a synchronous motor and bearings and stator temperature measuring device.

The size of the gear tooth surface meshing automatic timing and constant lubrication spray lubrication, lubrication is better, and can effectively reduce oil consumption, maximize reduce labor intensity of the operator. Large and small gears are equipped with steel shield protection, can effectively prevent splashing lubricant leakage and external dust. An inspection door on guard, enabling real-time viewing and maintenance. Sealing large gear excellent sealing performance of the end face using a labyrinth seal structure.

3.7 pneumatic clutch

Mill is low speed, heavy machinery and equipment, pneumatic clutch actuator to be configured according to the characteristics of pneumatic clutch in front of the mill rotation, a state of separation, the first no-load synchronous motor starts, after synchronous speed to be reached, PLC controlled by make pneumatic clutch and put into operation, driven mill at full capacity. The motor can be achieved, the host segments start, which reduces the current impact on the grid when the mill motor starter.

3.8 Slow gear

Slow transmission auxiliary micro drag to the mill installation, commissioning, maintenance bring great convenience. The device consists of a slow pass motor, reducer and straight tooth clutches and other components. Slow work unit, the main motor off automatically, mill shell can get less than 1r / min speed, so that the mill to easily stay in any desired position and at the same time realize reversing mill. When the motor power outage stopped the slow pass, using a ratchet pawl jammed the barrel can be achieved stall. This structure is simple, safe and reliable. Transmission of electrical, mechanical interlock control, to ensure the safe operation of the mill.

3.9 spray lubrication device

Large mill pinion gear belongs open, with low speed, heavy, continuous work characteristics. Mating surfaces using spray lubrication device. Spray lubrication with pump-driven, high-viscosity oil through the nozzle, timing, quantitative, spray evenly to large and vice surface friction pinion. Extend the life of the gears, improve the operating rate of the mill.

3.10 from the device

Mill for installation, maintenance, service convenience, set the lifting device. Lifting device from cradle seat, hydraulic jacks, rollers, etc., can be realized simultaneously lifting uniform. When you need to replace the main bearing lining parts and other maintenance, use the lifting device will Swiveling certain height from the top, and then along the journal bearing bush slip out or removed for repair and maintenance of other components. After the completion of repair work, when you want to #### the barrel, lifting device can not pay attention to the rapid relief should be used synchronous operation, the cylinder to slow down, to prevent accidental damage to equipment and other key components of the bush.

3.11 electrical parts and control and protection systems

(A) the electrical part

Mill electrical control using programmable logic controller (PLC) and touch-screen technology. For high and low pressure pump stations, bearing temperature, pneumatic clutch, slow transfer device, spray lubrication devices and systems such as the implementation of open parking interlocked control. PLC for the general failure of the mill can be adjusted to run their own state and an alarm signal. Indicates the fault location, to alert the operator, and issued a directive in the event of a serious failure to make the mill stops running. While using touch screen technology on the mill control has the following advantages:

1) replace the lights on the control panel, the output signal of the PLC communication cable to pass through the touch screen, while the corresponding indicator screen appears on the touch screen. The operator simply operate the touch screen to view;

2) replace the control panel buttons, as long as the operator presses the control buttons on the touch screen on the screen, you can put the control signal is transmitted to the PLC, program control by PLC;

3) If you need to detect analog signals, can not require secondary instrument, only the analog signal into the PLC. Re-transmission by the PLC to the touch screen, the touch screen to complete the monitoring of the analog signal;

4) If the control panel is not next to the host, and in the operating room, the operator can observe the operation of the device via the touch screen screen;

5) If a problem occurs, the touch screen can be observed directly to the point of failure, ease of maintenance mill. For example: When there is a limit not pull, if not a touch screen, you need to find the PLC program, and then find the program contact PLC input signal. The touch screen can be viewed directly into an electrical signal for each point is operating normally, if the limit is not energized, the screen on the touch screen will display the signal that is disconnected. This greatly facilitates the maintenance and use of equipment.

(B) the control and protection system

Mill electrical control system I provided mainly by: low voltage control cabinet (+ A), site operation box (+ B1, + B2, + B3) components.

1, low cabinet (+ A)

Mainly by the PLC, touch screen, overload protection, short circuit protection and so on. For lubrication of ball pressure, pressure from the top, bearing temperature measurement and control.

Touch screen installed in the control cabinet panel, through which you can watch bearing temperature, equipment operating conditions, to operate the equipment.

Control counter board installed a red emergency stop button, when it contacts energized, all devices stop working mill.

2, site operation box (+ B1)

Installed near the lubrication station. Has a low-pressure pump start / stop, high-pressure pump start / stop button on the box.

3, site operation box (+ B2)

Installed near the main motor. The box has a main motor starter, main motor stop button.

4, site operation box (+ B3)

Installed in the slow pass near the motor. Slow starter motor has passed on the box, slowly pass the motor stop button.

Hydraulic section 3.12

Hydraulic section includes high and low pressure oil stations and hydraulic lines, main bearings ensure safe and stable operation. Two parts at high pressure systems and low pressure systems, high-pressure part 2 sets of high-pressure pumps, respectively, to the two main bearing oil in the mill before the high-pressure pump start and stop automatic operation, the entire department in Bliss swing state, to avoid local heating, generate bush-burning phenomenon. Part 2 sets Low pressure pump, an open one prepare for two main bearings pour oil lubrication, lubrication and cooling play a role.

1) main bearing high pressure system: This system consists of two high-pressure, high-pressure outlet of each pump has a filter, directly from the low pressure pump suction pressure oil lines, reducing the suction pressure, so that the system design is more reasonable. Two high-pressure pump provides high pressure oil supply were the two main bearing bush, the two hollow shaft buoyant.

2) main bearing low pressure lubrication system: The system consists of two low-pressure pump (a running, a spare). When the pump fails to start work immediately spare pump, can ensure the normal operation of the host, and easy maintenance. Low oil outlet of the oil filter using binoculars mesh-type oil filter, oil filter when clogged can be replaced immediately to spare the chamber, while ensuring the normal operation of the system and easy maintenance. Low lubricating oil through binoculars mesh-type oil filter and then by the cooler after leaving the host bearing lubrication.

3) Cooling system: to provide a heat exchanger to reduce oil temperature. Heat exchanger installed in the low-pressure circuit, the use of water-cooled.

4) interlock and protection: the hydraulic system in the high and low pressure oil on the road are equipped with safety valves, hydraulic systems can achieve their over-voltage protection. The system also has the following electrical interlock: pumps and heaters, fuel tank low oil level, oil temperature high / low signal alarm.

5) local control hydraulic disc: Electrical components hydraulic station pre-wired to a separate tank on the junction box. Main bearing lubrication system is installed in the mill mainly by electrification control system in the control room. However, you can take advantage of local control Local / Remote selector switch on the lubrication system to provide local control panel on the cabinet door. When using local control, local control disc allows control of all pumps. Under normal operating conditions, local / remote selector switch is usually in remote mode. For the main bearing associated with the mill lubrication system for safe operation of all control logic as part of the PLC control panel.

6) Heating system: heating system consists of small power immersion heater. Oil temperature is mounted on the fuel tank through the submerged resistance measured by the sensor, immersion heater is controlled by the control logic input signal from the thermal sensor to achieve. Lights on the control panel indicate the working status of the heating element.