TRM type vertical grinding roll is designed, developeddevelopmentThe new grinding equipment ofBall millingIt is completely different. It can simultaneously performdry, grinding and grading, simple process flow, small floor area, low unit power consumption, low metal wear, low machine noise, high grinding efficiency, and large use of kiln tail gas compared with ball mill roll.
The production capacity of vertical mill depends on the specifications of vertical mill. For example, the raw material output of 3425 mill is 185 tons/hour.(34 represents the diameter of the center circle of the grinding plate, 25 represents the diameter of the grinding roller) 1915 grinds its raw material output of 45 tons/hour.(The specification of grinding roll is the same as above) If you need the output of vertical mill of other specifications, please provide the specifications together.Sometimes there may be some errors due to the great difference of the grinding materials.
Raymond mill is also calledraymond mill , full English name: Raymond mill.It is applicable to the preparation of various mineral powder and coal powder, such as fine powder processing of raw material ore, gypsum ore, coal and other materials.From the appearance, it looks like a steel container standing upright, with air inlet and outlet, and a feed inlet in the middle.There is a motor at the lower part of the grinding roll to drive the internal grinding rod and grinding plate to rotate to crush or grind the materials to be grinded. The finished materials are blown up by the air inlet. There is a separator at the upper part of the grinding roll to separate the coarse and fine powders, and then the air through the grinding roll is taken out of the air outlet for collection.
Purpose of each process in grinding roll room
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① Grinding the work roll and backup roll of four continuous rolling mill, single leveling and finishing mill;
② Storage of various production turnover rolls;
③ Disassembly and assembly of roll and bearing pedestal;
④Roller bearingCleaning and maintenance of seats and bearings;
⑤ Polishing and roughening of the work roll surface; ⑥Various cutting edge grinding and some small rollers grinding.
Function of technical parameters of grinding roll
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The surface technical characteristics of the toothed roll mainly refer to the number of teeth, tooth angle, tooth top plane and inclination of the grinding teeth on the roll surface, as well as the arrangement, average speed and speed ratio of the two grinding rolls.
The number of teeth is related to the size and flow of grinding materials and the degree of grinding required.For example, when the particle size and flow of the material to be grinded are large or the material to be grinded is required to be coarse, the number of teeth should be less;On the contrary, more teeth shall be allocated.Under the same other conditions, the smaller the number of grinding roller teeth, the greater the distance between the two grinding teeth, and the deeper the tooth groove, which is only suitable for grinding materials with large particles.If it is used to grind fine materials, the materials will be embedded in the tooth groove without grinding.The more teeth of the grinding roll, the smaller the distance between the two grinding teeth and the shallower the tooth groove, which is only suitable for grinding materials with small particles.If it is used to grind the materials with large particles, the wheat husk will be easily crushed when the flow is small, and the middle part of the materials will not be fully grinded when the flow is large, the grinding teeth will be easily worn, and the output will be low and the power consumption will be high.
Production practice has proved that less teeth save power, lower grinding temperature, longer service life of grinding roller, can adapt to high flow rate, easily maintain integrity of bran, have more slag particles than more teeth, and have less flour.Under the same other conditions, the stripping rate and powder extraction rate are low.
The tooth angle is divided into front angle and rear angle.During the grinding process, the material falls between two grinding rollers, is held by the slow roller, and is crushed by the fast roller.The force acting on the material between the grinding rollers mainly depends on the front angle.When the current angle is reduced, the shearing force increases, the extrusion force decreases, the shearing and crushing effect on materials is strengthened, the stripping rate increases, the proportion of slag cores in the mill offal increases, the quantity of fine powder decreases, the cortex is fragile, and the bran stars in the powder increase, so the quality may decline, but the higher material flow can be handled with lower power consumption;When the front angle increases, the shear force decreases, the extrusion force increases, and the extrusion force plays a dominant role. The proportion of slag core in the mill offal decreases, the quantity of fine powder increases, the cortex is not fragile, and the flour quality is good, but the crushing capacity decreases, the power consumption is high, and the processing flow is low.
Although the rear angle of grinding teeth does not play a major role in grinding, its size is related to the height of grinding teeth and wear resistance.When the tooth angle remains unchanged and the rear angle increases, the height of the grinding teeth decreases and the thickness increases, which improves the wear resistance of the grinding teeth and prolongs the service life of the grinding roller.
(3) Addendum plane
The tooth top of grinding teeth for new wire drawing shall not be too sharp, and a certain tooth top plane shall be reserved according to the size of grinding teeth.The tooth top plane can achieve a more moderate crushing effect on materials and reduce the generation of bran;It can ensure that the grinding roll is an accurate cylinder after wire drawing, and improve the operation stability;It can also improve the service life of the grinding roll and stabilize the running state of the powder path.
The gear grinding slope is the key to the cross point of materials produced by the opposite rotation of two grinding rollers and the stripping, scraping and grinding.If the grinding teeth are not inclined, the grinding teeth of the fast and slow rollers will be parallel to each other, and unstable and wrong meshing will occur between the two rollers during grinding, which will not only easily cut the bran into filaments, but also cause vibration of the grinding rollers, which will affect the grinding effect.The grinding gear must not only have a slope, but also be installed correctly.
The two roll grinding teeth form many intersections with the material on both sides of the grinding area. When a pair of grinding rollers rotate in opposite directions, the fast roll grinding teeth and the slow roll grinding teeth form many intersections. When the rolling distance between the grinding rollers is less than the material to be grinded, the material is subject to relatively strong shear at the intersection.When there are many cross points in the grinding area, the average chance of materials being sheared in the area will increase, and the crushing capacity of the equipment will increase.
Under the same other conditions, when the slope is large, the number of cross points in the grinding area is large, and the degree of material crushing in the grinding area will be increased. The skin is fragile, the product quality is poor, but the power consumption is low.Therefore, smaller slope should be selected when processing hard wheat, old wheat, low moisture wheat and high quality requirements.When low power consumption is required, larger slope can be selected.
(5) Arrange
In the case of blunt to blunt arrangement, both fast and slow roll grinding teeth adopt large rake angle, which has large extrusion force on materials, small shear force, and moderate crushing effect. The leftovers are large in bran flakes, less in slag and core, but more in flour. The flour contains less bran and has good quality, but high power consumption.It is suitable for processing hard wheat, low moisture wheat, and the situation that requires bran integrity and low flow.
In front to front arrangement, the shearing effect on the material is strong, so the degree of fragmentation is high, the power consumption is low, the bran pieces in the milled material are broken, and there are more dregs and cores but less fine flour, which is suitable for processing soft wheat, high moisture wheat and high flow requirements.
(6) Average speed
The grinding roll is divided into fast roll and slow roll, with a certain rotational speed respectively. The rotational speed of the grinding roll is generally determined by the rotational speed of the fast roll.The higher the rotational speed, the higher the linear speed of fast and slow rolls, and the higher the average linear speed.The average linear speed of the two grinding rollers is related to the treatment flow. The higher the average linear speed, the greater the treatment flow and the higher the output of the mill.
If other conditions remain unchanged, the greater the speed ratio, the stronger the grinding effect on the material.The larger the speed ratio is, the more teeth are peeled and the more times the material is peeled, and the degree of crushing will obviously increase;But the bran is fragile, and the ash content of slag, core and flour increases, so does the power consumption.Therefore, the selection of speed ratio must adapt to the process, raw material properties, grinding requirements, etc.
If the speed ratio is increased but the linear speed of the fast roll is not increased correspondingly, the reduction of the linear speed of the slow roll will reduce the speed of materials passing through the grinding area, which will lead to the decline of the productivity of the mill.
(8) The new and old degree of grinding roller
The newly drawn grinding roll has sharp tooth angle and strong grinding effect.That is, high stripping rate, fragile bran, more granular materials, less fine powder, low power consumption, and can adapt to higher flow.However, after a period of time, due to the blunt tooth angle, the grinding effect is reduced, the output is reduced, the bran flakes in the milled product are large, the flour is more, the slag particles are reduced, and the grinding temperature is increased, especially the power consumption is increased.Therefore, the new and old grinding teeth will affect the grinding effect and the balance of powder path load.
Common problems and solutions of grinding roll
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Grinding roller body is worn
Vertical millDuring the use of the grinding roll body and wear-resistant liner, due to the pressure of the roller, the reaction force of the material, and the friction resistance between the material and the grinding roll liner;The shear stress of the roller, the pressure of the hydraulic system of the roller mill and the apparent compressive stress of the vertical mill due to the material grinding angle interact comprehensively. These forces act on the effective rolling area of the roller of the vertical mill.Once there is a fit gap, there will be impact and collision between the grinding roll body and the lining plate, which will aggravate the wear between the body and the lining plate. In serious cases, the lining plate will crack or even break, causing the lining plate to fall off and the machine to be damaged, especiallyReducerDamage, causing malignant events.Once such problems occur, it is difficult to solve them with general repair methods. Disassembly, welding, and machining are time-consuming and laborious, resulting in greatly prolonged downtime, which brings huge irreparable economic losses to enterprises.In view of the above problems, developed countries such as Europe and the United States often usePolymer compositesCarry out rapid repair of roller body wear of vertical mill, in which the more mature Youfushelan series are applied.With its excellent mechanical properties and good plasticity, the problem has been successfully solved.It can not only extend the service life of equipment and improve productivity, but also simply and effectively avoid the secondary possibility of this problem without taking up additional downtime, so as to protect the safe and continuous production of enterprises.
Wear of grinding roller bearing chamber
The assembly requirements of roller bearing of vertical mill are relatively strict, and enterprises generally place the bearing indry iceAssembly by means of medium cooling.Bearings andBearing chamberOnce there is a gap between them, the normal operation of the bearing will be affected, which will lead to bearing heating, and in serious cases, it will lead to bearing sintering.Traditional methods such as welding and brush plating have certain disadvantages: repair welding will produce thermal stress that will damage the bearing material, and even deform or break in serious cases;Brush platingThe pollution is heavy, and the coating thickness is limited, so the application is greatly limited.Polymer composites not only have the strength and hardness required by metals, but also have the flexibility (variable relationship) that metals do not have. Through "mold repair", "component correspondence", "machining" and other processes, the size matching of repair parts and matching parts can be ensured to the maximum extent;At the same time, the composite material can effectively absorb the impact of external forces, greatly resolve and offset the radial impact of the bearing on the shaft, and avoid the possibility of clearance, which also avoids the secondary wear caused by the increased clearance of the equipment.
