Common Malfunction and Treatment of Vertical Milling
one. Mill vibration causes and treatment:
1. Vibration measurement component failure:
Grinding roller just down there will be vibration, the operation of the procedures and parameters are normal, and the scene did not feel the vibration, after inspection found that vibration meter loose, re-tighten, grinding normal.
Vibrometer loose is common, then the control operation screen parameters are no exception, the scene without vibration. Prevention of the matter requires more attention to the usual patrol, and keep clean.
2. Roller skin loose and loose lining
The central control vibration is too large, the site found a regular vibration and boring sound of the vibration, emergency stop grinding into the mill to check the splint bolts were no significant loosening, grinding inside and outside the foreign body, everything is normal, into the mill was found a roll Pisi loose.
Roller skin loose is a very regular vibration, because the diameter of the roller than the diameter of the disc, so the disc rotation less than a week, there will be a vibration, coupled with on-site voice recognition, you can determine a roller roll skin appears loose.
Lining loose, the general performance of a continuous vibration, the scene felt a disc rotation every three weeks there will be vibration.
When found roll and liner are loose, you must immediately stop grinding, grinding into the detailed examination, and to guide the handling of professionals, or when its off, it will cause serious accidents.
3. Hydraulic station N2 capsule pre-pressure imbalance, or too high or too low
When the N2 ball is not balanced, the rod of the buffer force is different, so that the mill vibration. Too high, low buffer capacity is weakened, but also easy to make the mill vibration is too large, so the preload pressure of each N2 capsule should be set strictly in accordance with the given value, and regularly check to prevent leakage, leakage Gas, pressure is not normal.
4. Feed volume is too large, too small or unstable
Mill feed, resulting in too much material within the mill, the mill conditions malignant, it is easy to instantaneous vibration jump stop. Because the waste can not be used, open grinding spit slag directly into the grinding, grinding roller vibration is too large, while the performance layer thickness, inlet pressure, which is due to open spits when the slag more, with belt scale feeding , Into the grinding feed to become more. At this time should be a significant reduction in belt scale feeding, such as spit residue normal, then added to normal.
Feeding volume is too small, the mill material is too small, thin material layer. Between the grinding disc and the material roller buffer capacity is insufficient, easy to produce vibration. Vertical mill trial production, due to mechanical requirements required by 70% of the feed, the feed is too small, which is the production of neutral grinding vibration one of the reasons. So by feeding large particles of material to ensure smooth operation of the mill.
Unstable material to grinding conditions within the chaos, easy to vibration, to achieve a smooth operation of the mill, one of the important factors is to make the average smooth feeding of materials.
5, the system air volume is insufficient or unstable
When the kiln cut to 200t / h, the mill will have a large start spit residue, less than two minutes will be vibration jump stop, that the hot air inlet material, but clean up, the mill still does not start up. Analysis: due to the kiln exhaust less, the mill due to insufficient air volume and vibration. At this time only requires kiln production, and minimize mill feed, in order to open the mill. Or increase the opening degree of the air-conditioning baffle (or recirculation windshield opening).
Kiln grinding operation requirements integration. Mill operation will affect the kiln, while kiln operation will also affect the mill. Sometimes the kiln condition instability, high temperature fan over the wind fluctuations, but also accompanied by wind temperature changes, so that grinding conditions unstable, easy to produce vibration, which is through the cold wind and cycle wind baffle adjustment to ensure that the mill inlet negative pressure Stable, and try to ensure that the mill's temperature stability, so that the mill work properly.
6, grinding pressure is too high or too low
ATOX grinding machine can clearly feel the grinding pressure on the impact of mill vibration, when feeding a certain amount, the pressure is too high, will have a grinding capacity is greater than the finished product into the required capacity, resulting in grinding vibration. On the contrary, too much pressure caused by too much material within the mill, resulting in large vibration.
7, separator speed is too high
In the early stage of the trial production, the rotor speed is generally not set at the maximum. Because at this time the amount of feed and air volume is very small, elected powder machine speed is too large, easy to produce over grinding, so that grinding powder increased, too much powder can not form a solid material bed, roller 'eat' material Deep, easy to produce vibration. So the mill did not meet the design output, the requirements of the particles into the grinding material is too large, easy to operate.
8, into the grinding temperature changes too high or too low
When the outlet temperature of high-temperature fan changes, mill conditions will change, too high to the disc plate on the bed is not easy to form, too low can not dry material, causing the nozzle ring blockage, bed thicker makes the mill abnormal vibration .
This situation occurs by adjusting the mill water, humidification tower water, or mixed with cold air, circulating wind, stable mill inlet and outlet temperature, stable mill conditions.
9, the grinding temperature of the high or too low
Vertical mill is generally open, the impact of its environment is very large, the current heavy rain and rain, so that the mill body and the pipeline temperature of the sudden change in the export temperature is rapidly reduced, which is extremely easy to cause the mill jump, must be quickly adjusted: Heating, pull the wind, cut the material adjusted to normal. The grinding temperature is also affected by the number of materials into the mill, composition changes, changes in large, you need to adjust the water, feeding and the baffle opening to stability.
Outlet temperature is too high, prone to empty grinding, the material in the disc can not form a solid material bed, resulting in vibration, too easy to plug the nozzle ring, but also easy to produce vibration, then adjust the inlet temperature, grinding water, May be appropriate to increase, reduce yield.
10, nozzle ring block serious
When the material into the mill is very wet, mixed with large, insufficient air flow, feed too much, wind speed instability will have a nozzle ring clogging, blocking serious, so that the disc around the wind speed, air volume is uneven, Smooth, resulting in large vibration. At this time need to stop grinding clean, re-open grinding to pay attention to reduce the chunk into the mill, increase air volume, reduce feed, while maintaining grinding conditions stable to prevent the nozzle ring block.
11, into the grinding lock valve impact
When the lock air valve clogging, no material into the mill, then the resulting air mill will produce a large vibration. When the lock air valve leakage, will produce abnormal vibration.
12, grinding within a foreign body or large
Usually pay attention to whether the loose bolts within the bolt, the bolt is desoldering, including lock air valve. Digang and Chizhou have emerged three lock valve plate off the wall, causing the mill vibration. When a large iron block in the mill, it should be promptly stopped grinding out. Even if he does not affect the vibration jump, will also cause damage to the mill, for example, damage to the baffle ring. Chizhou 1 # mill has this phenomenon, due to mill capacity, the general iron ore is not easy to find, and finally destroyed the baffle to know.
Large into the mill, in addition to blocking the nozzle ring, there may be grinding roller, resulting in vibration, so to put an end to the chunk into the mill. Second, the vertical grinding fineness running rough reasons and treatment 1, the election of the speed adjustment device improper device
Adjusting the speed of the rotor is the most common way to adjust the fineness, and the most important one. Usually change the fineness: the first thought is to adjust its speed, running rough when increased speed.
2, ventilation is too large
In the trial production, with the hot stove or feeding less, the mill internal ventilation is small, the separator speed is set to 70-80%, the basic fineness can be achieved. With the increase in the hot air kiln, mill ventilation increased, EP fan baffle increase, fineness will rise, then should gradually increase the speed of the separator, to ensure the fineness of qualified.
For example: when the kiln feeding to full load, the kiln large air volume, or even EP fan open to 100%, grinding entrance or positive pressure, when the fineness is likely to become larger, even if the separator can not be added to the limit Fineness qualified. At this time can be considered open grinding bypass baffle, but this method is more dangerous, easy to make the mill jump. So must be careful, each 1% have to observe a longer time to ensure the smooth operation of the mill in a certain range can reduce the fineness, this method is limited to excessive air volume.
3, grinding pressure is small
ATOX mill pressure can be given in the control, the general open grinding when the pressure is set to a minimum, with the increase in production, must be gradually pressurized, or because of crushing and grinding capacity is insufficient, resulting in running rough phenomenon.
4, the temperature effect
Mill exit temperature is rising rapidly, or to maintain a high temperature, the grinding material may also run rough, because the temperature rise in the process of changing the grinding fluid velocity and the internal energy of the mill material to increase the fine material to do Brownian motion Large material is pulled out of the grinding body. This may be the kiln wind temperature, air flow changes or into the grinding material moisture changes can be formed when the internal grinding spray solution. Mill and humidification tower in series process line, adjustable humidifier tower water, in the case of air flow can be mixed with circulating wind or cold wind.
Into the grinding instability is easy to make the grinding conditions of chaos, wind speed, air volume fluctuations, resulting in intermittent running rough. Solution: stabilize the amount of material into the mill to ensure that the amount of grinding pressure, or moderate to reduce production.
5, grinding materials into the grinding poor
Into the mill material strength and hardness, or material particle diameter, difficult to break and grinding, plus the number of cycles to stop grinding increase, the final performance of the mill too much material, the solution: a. To improve the grinding material into the grinding And diameter b. Appropriate amount c. Moderate to reduce the yield.
6, equipment, serious wear and tear
Mill after a long period of time, the election device blade, roll roller skin, disc liner, nozzle ring, and so will be subject to varying degrees of wear and tear, this wear can lead to run rough fineness.
Optional powder device, nozzle ring, etc. should pay attention to maintenance, damage to the timely replacement, repair. 7, equipment failure and ran rough
In the period of time when the separator can not be recovered, the operator can control the pressure, air volume and temperature to reduce the fineness to about 21%, which can basically be used for kiln calcination.
Usually fineness is not a certain reason to run rough, the same is not only a way to reduce the fineness can be found running the main reasons for this reason, take the method, and can use other methods to compensate for this method Of the shortcomings, in order to achieve the purpose of reducing the fineness.
Third, into the grinding material blocking causes and treatment
Rotary valve is blocked, the cleaning is very dangerous, very laborious, serious constraints on production. The reasons for the blockage and treatment methods are the following: 1,
Material viscosity, easy to accumulate wet material
Raw materials into the grinding mill by a variety of ingredients, each component of moisture, viscosity are different. The early mining of limestone on the surface layer, non-limestone material content is high, these particles are small particles, strong viscosity, moisture is easy to accumulate.
2,
Stuck stones
ATOX mill rotary valve, and sometimes large stones, causing the rotary valve body does not move, but the sliding joint of the special features of the motor and immediately jump stop, causing the belt into the wear and continue to block the material to solve this problem is to reduce the Into the mill in the bulk of the material.
Usually due to the lock valve in the production of mechanical failure caused by the phenomenon of congestion, but does not rule out the possibility, so in peacetime to pay attention to its maintenance and inspection, timely detection of problems in time.
Phenomenon, Reason and Treatment of Mill Trip
Phenomenon
the reason
Approach
Increased vibration current value of the mill (mill vibration curve increases with the current curve increases beyond the limit)
There is a large foreign body on the disc
Shutdown manual cleaning
Mill ring was blocked by limestone
Mill exit temperature is too high
Adjust the cold, hot damper opening
Roller Bolts Loose Shutdown Manual Treatment
Hydraulic station hydraulic pressure low to re-adjust the work of the hydraulic station pressure and pressure relief to a certain amount of feed too much
Increase the fan and the opening of the circulating damper or fill cold wind mill current increases the vibration value decreases, the mill current decreases vibration value but increases
Induced draft fan air flow is not enough to lead to the classifier on the warehouse wall
The limestone powder falls back to the grinding disc to cause the roller to slip
Increase the fan and circulating damper opening or fill the cold wind
The speed of separator is too high
Adjust the classifier speed (reduced) vibration suddenly increase the current change is not
Feeding equipment failure, the phenomenon of breaking material
Shutdown inspection, processing