Cone crusher set cone assembly abnormal rotationDate: 2019-08-08 Views:
Cone crusher because its broken ability is strong, the advantages of large processing capacity, this paper cone crusher production of sharing in the slime for a concentration of fixed cone assembly clockwise rotation and discharging mouth anomaly smaller problems, through field observation, investigation, summarizes the abnormal rotation of reason, put forward the measures to solve and prevent abnormal rotation.
1. Cone crusher working condition and failure
1.1 abnormal rotation characteristics of fixed cone assembly
A concentrator processes 450,000 t of ore per year.The processing process of mineral processing plant is crushing - grinding - flotation.The crushing system consists of three stages of closed-circuit crushing with screening operations, namely, a jaw crusher, a two-stage single-cylinder hydraulic cone crusher, and a three-stage multi-cylinder hydraulic cone crusher.There are two sets of systems in the grinding workshop, which are respectively: the second stage ball mill and grading mechanism to form the no. 1 old closed-circuit grinding system, and the first stage ball mill and cyclone to form the no. 2 new closed-circuit grinding system.Flotation for a rough, two - time sweep, two - time selection, middle - ore sequence return.
In this concentrator cone crusher, the fixed cone assembly often rotates in an abnormal clockwise direction and the discharge port automatically becomes smaller, which affects the normal production.Although many times to the production site to understand the equipment failure, find the cause, and cone crusher equipment overhaul, have changed the lock ring, lock cylinder, adjustment ring, moving cone assembly, fixed cone assembly, liner shape, have failed to solve the fixed cone assembly abnormal rotation of the fault.Later, technicians observed and investigated at the production site and found that the fixed cone assembly of the cone crusher was abnormally rotated with the following characteristics:
1) when the red number of the locking cylinder oil pressure gauge is 18.5 ~ 21.5mpa, and the fluctuation of the number of the oil pressure gauge does not exceed 0.1mpa, the cone assembly of the cone crusher can be locked without rotation.
2) when the red number of the locking cylinder oil pressure gauge is 17.5 ~ 22.5mpa, and repeatedly jumping up and down, the cone assembly of the cone crusher can not be locked and rotation.
3) in the period of 14:00 to 20:00 every day, the cone assembly of the cone crusher often occurs abnormal rotation failure;In other periods, such as morning and evening shift, the fixed cone assembly rarely has abnormal rotation failure.
4) when the hardness of ore increases obviously, the number of abnormal rotation failure of cone assembly of cone crusher increases obviously.
5) when the movable cone liner and fixed cone liner wear to the later stage, cone crusher assembly abnormal rotation failure of the number of significantly increased.
6) when the motor current exceeds 260A, the number of abnormal rotation faults of the fixed cone assembly is significantly higher;When the current is lower than 220A, the frequency of abnormal rotation failure of fixed cone assembly is obviously less.
7) the failure of abnormal rotation of fixed cone assembly occurs not continuously, but intermittently.
1.2 cause analysis of abnormal rotation of fixed cone assembly
After a week of observation and investigation, the hydraulic pressure of the hydraulic system is normal and stable, the cone assembly of the cone crusher can be locked without rotation. The reasons for the abnormal rotation of the cone assembly of the cone crusher are summarized as follows:
1) when there is leakage of hydraulic oil in the hydraulic system, the oil pressure will jump up and down, and the fixed cone assembly will rotate due to loose lock.
When the hydraulic system of pipe joints, all kinds of valves, sealing element of the place such as seal wear or fails, prone to leakage of hydraulic oil or the leakage phenomenon, the hydraulic system of hydraulic falling fast, hydraulic system pressure filling system automatically start the gear oil pump, automatic pressure and oil pressure is rising fast, then lock cylinder hydraulic table red Numbers in 17.5 ~ 22.5 MPa jumping up and down, set the friction of the cone assembly (lock) is not in the normal range.Therefore, the cone assembly of the cone crusher can not lock and rotate.
2) when the oil temperature of the hydraulic system slowly rise, the oil pressure will slowly decline, less than 18.5mpa, cone crusher assembly can not lock and rotation.
Due to lubrication station of cone crusher with 1 typhoon only cold system to reduce and control the oil temperature, since the device installed and put into production, there have been problems of higher temperature of lubricating oil, especially in the summer, lubricating oil temperature is difficult to control in a safe range, so on the transformation, increase 1 typhoon cooling system to reduce the effect of oil temperature, but is not ideal.
The concentrator is located in southern China, and the environment temperature of the workshop is higher than other periods during the period from 14:00 to 20:00 every day.Because there is only one steel plate between the hydraulic oil tank and the lubricating oil tank, the heat of the lubricating oil is transferred to the hydraulic oil quickly, resulting in the hydraulic oil temperature rise of the hydraulic system, hydraulic pressure drop, when the oil pressure falls to 18.5mpa or below, the cone assembly of the cone crusher can not lock and rotation.The environment temperature of morning and evening shift is relatively low, the hydraulic oil temperature of the hydraulic system is not high, the oil pressure is relatively stable, HP200 cone crusher fixed cone assembly can lock without rotation.
3) when the hardness of ore increases significantly, crushing ore needs more crushing force, and the reaction force of a given cone assembly of crushed ore is greater, even if the hydraulic pressure of the cone crusher hydraulic system is stable, the pressure of the locking cylinder is not enough, the fixed cone assembly is difficult to overcome the reaction force.As a result, the fixed cone assembly rotates abnormally.
4) when the movable cone liner and fixed cone liner wear to a later stage, the shape of the crushing cavity changes. Even if the ore crushing force does not increase significantly, the component force of the reaction force in the horizontal circumference direction increases significantly, and the fixed cone assembly is difficult to overcome the action of the reaction force.As a result, the fixed cone assembly rotates abnormally.
5) if the cone crusher into the hopper mouth feed too much ore or ore silt content is large, the size of discharge mouth and adjust too fine, resulting in broken ore can not be quickly discharged.This will also lead to cone crusher fixed cone assembly stress increase, can not lock and rotation.
2.Transformation and application of cone crusher
2.1 equipment transformation
After observation, investigation and summary of the causes of abnormal rotation of the set cone assembly, the HP200 cone crusher is reformed to completely eliminate the abnormal rotation of the set cone assembly:
1) redesign and make the locking ring.
Add 4 locking cylinders to the locking ring, that is, make and install 12 locking cylinders.Therefore, the downward pressure of the locking cylinder of the locking ring to the adjusting ring is 295.61kN.If the friction coefficient between the locking ring and the adjusting ring is set as 0.1, the fixed cone assembly connected with the adjusting ring by bolts is subjected to the horizontal circumferential friction force (locking force) of 29.561kn.The fixed cone assembly is subjected to 1.5 times more frictional force (locking force) in horizontal circumference direction than before modification.
2) check the hydraulic oil, safety valve, solenoid valve, hydraulic cylinder, seal, etc. regularly to ensure that the hydraulic system neither leaks nor leaks, to ensure the oil quality and oil pressure stability.
Replace or tighten the loose hydraulic oil pipe joint in time, replace the broken and perforated oil pipe, replace the worn hydraulic cylinder seal ring or eliminate the internal leakage fault in time.Eliminate oil pressure fluctuation and prevent abnormal rotation of fixed cone assembly.
3) install a cooling circulation water pipe in the hydraulic oil tank, and use the cold water inside the water pipe to take away the heat of the hydraulic oil outside the water pipe in time to ensure that the temperature of the hydraulic oil is within the normal range.
2.2 application effect
The production practice of cone crusher after 2 months of reconstruction has achieved good application effect.
1) increase the cooling circulation water pipe, and the oil temperature of lubricating oil and hydraulic oil decreases by 5℃ on average, which is conducive to stabilizing the pressure of the hydraulic system.
2) within the normal wear and service life range of the liner plate, the inner fixed cone assembly only rotates one gear for 8h, that is, the discharge port decreases by 0.2mm.This is normal and the fixed cone assembly does not rotate abnormally.
3) as long as the crushing ratio between the first section crusher, the second section crusher and the third section crusher is well controlled, to ensure that the cone crusher feeding particle size, feeding load and discharging particle size, the total achievement of fixed cone will not occur abnormal rotation.