Do you know two ways to align the roller center of the vertical mill?
Date：2019-10-21 16:02 Source：cementepcViews:
When the raw material is easy to wear, the output of vertical mill decreases.The wear of the roller lining plate often causes the vibration of the mill to be repaired, and the maintenance cycle is often short.Therefore, it is very important to research, analyze and summarize the key maintenance technology of the mill -- alignment of roller center.Do you know two ways to align the roller center of the vertical mill?
1. Cause and harm of deviation of grinding roller center
The quality of the mill roller is directly related to the normal operation of the mill, and it is also a key to ensure the output of the mill.Especially roller group center and mill grinding track changes not overlap, mill run under abnormal condition, adaptability to materials decreases significantly, especially large materials into the mill, roller group of swing range is small, difficult to large materials grinding into qualified product, it is difficult to form at the bottom of the roller is suitable for material thickness, mill vibration shock often stop.Therefore, the installation unit is required to install the vertical mill in strict accordance with the installation requirements of the equipment.
During the operation of the grinding machine, the grinding roller will produce higher material layer resistance under the action of loading pressure, and the grinding roller has a certain rotation resistance relative to the roller axis. The combined force of the two forces forms the rotation resistance of the grinding roller.When the grinding roller is well aligned, the thickness of the upper layer of the grinding ring is stable, the rotation speed of the three grinding rollers is constant, and the output is stable.
Due to the constant loading force, as the roller set of uneven wear, material layer resistance increases gradually, by grinding the material thickness between parts is reduced, the material layer buffering capacity is abate, roller mill and sensitivity to material layer thickness increases, the grinding operation caused by the uneven wear of beating, roller dynamic to paint a more serious, grinding parts running stability, destructive to material thickness increases, this is a vicious circle process;When the stable material layer thickness between the grinding roller and the grinding disc is destroyed, it causes the sharp vibration of the grinding machine.
2. Alignment of grinding roller center
(1) alignment method for the center of vertical grinding roller
The method of aligning the grinding roller with the aligning rod is as follows: unloading the tension hydraulic station before the middle.First, remove the material on the pressure frame and find out the alignment mark made by the manufacturer.Then use 0.5mm thin wire to mark the center of the pressure frame.
Make the center of the pressure frame coincide with the center of the main reducer with the plumb.Then use 3 steel needles to set 3 grinding rollers, the horizontal deviation of steel needles is within ±5mm;The clearance between the center of the pressure frame and the center side of the main reducer is 1mm, and then the clearance between the impact plate is adjusted to ≈5mm.
Through maintenance practice, it was found that the method of using only the grinding roller alignment rod alignment roller has many disadvantages and poor accuracy, such as alignment rod and alignment roller alignment hole coordination accuracy is extremely poor, alignment rod insertion after the free free momentum is very large, has exceeded the alignment requirements of 5mm accuracy range.
(2) alignment of the center of the vertical grinding roller method ii
During maintenance, the fundamental purpose of the center of the grinding roller is to ensure that the three grinding rollers are evenly distributed around the center of the grinding disc. The main purpose is to adjust the radial distance and axial distance of the grinding roller relative to the center of the grinding disc and the tilt Angle of the grinding roller to make them consistent, so as to ensure that the grinding roller is still in good alignment in dynamic operation.In order to improve the accuracy of roller center alignment, practical and effective methods are explored and summarized, thus improving the maintenance quality and equipment performance.
There are three hinge bearings of grinding roller on the pressure frame. The position of the pressure frame directly affects the position of grinding roller.Therefore, the center of the downforce frame must be found first.The pressure frame is manufactured according to equilateral triangle. The pressure frame center is determined by drawing lines respectively through the center of the end of the pressure frame and the center of the hinge seat of the side grinding roller. The center of the output flange of the reducer is aligned with the line setting hammer from the center of the pressure frame.
Adjusting the alignment of the center of the output flange of the wire hammer and reducer is the installation and adjustment process of the pressure frame. The positioning gap between the pressure frame and the guide plate is mainly adjusted. When the gap between the front guide plate is zero, the gap between the guide plate after the test must be consistent.The gap of guide plate in the original design was 5mm±0.5mm, which has been proved to be larger in practice. Now it is adjusted to 3mm±0.5mm, with good effect.
Grinding roller mainly depends on matching grinding roller and lining plate;The maximum outer diameter of the 3 roller lining plates has been strictly tested in advance, and the deviation of outer diameter is controlled <4mm.The thickness of each liner is also strictly tested, the thickness deviation is controlled <1mm, and the parts exceeding the standard are repaired.This directly ensures that the vertical deviation of the grinding roller is less than the standard requirement of 5mm. Check can directly measure the alignment hole of the grinding roller and the lead-straight distance of the reducer output flange, without the aid of the alignment rod.
At this time, the grinding roller horizontal deviation will usually <5mm, check, along the alignment rod to measure the grinding roller alignment hole and the distance between the midpoint, usually do not need to deliberately adjust;In case of excessive horizontal pair, the deviation of the center of the frame under pressure and the horizontal deviation of the grinding roller should be controlled by balance.
The alignment method in this paper solves the problem of consistency of inclination Angle of grinding roller, because the consistency of inclination Angle of grinding roller is very important for dynamic and stable operation and is beneficial to the balanced wear of grinding roller.