What are the causes of holding the bearing of hammer crusher?

Product introduction:https://www.cementepc.net/crusher/Hammer-crusher.html

Hammer crusher bearing hold, is the bearing in the process of running a lot of heat, heat in a short time can not be scattered.Causes the bearing temperature to rise sharply, finally holds the bearing dead.This phenomenon is common in equipment overhaul and production service site.What are the causes of holding the bearing of hammer crusher?
 

1. Improper assembly

 

1.1 improper fit between bearing outer ring and bearing seat hole or bearing inner ring and shaft during assembly.

In the process of assembly, sometimes the inner hole of hammer crusher is not repaired, its size is measured, new bearing is replaced for assembly, and the temperature rise is found to be too high after test run.During the inspection, it is found that the bearing seat hole of hammer crusher has been deformed, which causes the outer ring of the bearing to be squeezed, resulting in the radial clearance of the bearing becoming smaller, the rolling body rotating unevenly and the wear becoming worse.The clearance between the bearing inner ring and the shaft is too large, and the bearing inner ring rotates with the rolling body and the shaft, resulting in heat and vibration of the bearing due to friction.
 

1.2 improper control of bearing heating temperature during assembly.

During the heating operation, if the temperature of bearing heater of the debugging hammer crusher is too high, the hardness and accuracy of it will be reduced due to tempering, thus the temperature of the bearing will rise, which will lead to further wear and damage of the bearing.
 

1.3 improper adjustment of bearing clearance of hammer crusher during assembly.

In the actual work, many installations sometimes only by hand debugging, clearance is too large or too small, can not meet the production needs.If the axial clearance of hammer crusher is too small, it is easy to cause bearing heating, accelerate pitting corrosion, and even make the rolling body stuck or glue damage;If the axial clearance is too large, the impact force of the moving pair will increase and the stiffness will decrease, which will lead to abnormal sound in operation, and even cause serious vibration or damage to the cage.

2. Oil seal problem

Oil seal is used to seal the rotary shaft of hammer crusher seal oil seal elements, and the cavity is basically static, so the oil seal is also known as rotary shaft lip seal ring.For the oil seal that takes pair lip, its pair lip rises dustproof effect, prevent impurity to invade, in order to prolong oil seal life, but pair lip place often is lubricated undesirable, frictional bigger, cause oil to seal dry attrition and damage, must fill grease between double lip when installing double lip oil seal so.
 

3. Gap problem

In the process of assembly, if the size of the spacer is not carefully checked and the assembly is tested, the temperature will rise rapidly after a certain period of time.The size of the outer ring of the bearing of hammer crusher has been determined by the end cover and the stop mouth of the bearing seat. The size of the spacer is reduced, and the size of the inner ring is adjusted by the round nut. Finally, it is pressed down, and the axial clearance of the bearing becomes smaller, which causes heat in the running process.

4. Lubrication problem

Bearing grease should not be too much, too much grease will increase the friction torque, hammer crusher bearing temperature rise;However, if the amount of fat is too little, the reliable lubrication cannot be obtained and dry friction occurs.Generally speaking, the appropriate amount of grease is 1/3 ~ 1/2 of the total void volume in the bearing, therefore, according to the requirements of use, regular injection of appropriate amount of grease.

The page source:https://www.cementepc.net/productknowledge/What-are-the-causes-of-holding-the-bearing-of-hammer-crusher.html

What are the factors that affect the production capacity of the tube mill?resolved

Product introduction:https://www.lvssn.com/mill/Tube-Mill.html

There are many factors that determine the production capacity of tube mill. Only when we understand these factors can we better solve the problem. What are the factors that affect the production capacity of tube mill?
 

1. Factors of the tube mill itself

 

(1) type

The productivity of wet mill is higher than that of dry mill.The production capacity of rod mill is higher than that of ball mill.
 

(2) diameter and length

The production capacity of large-diameter mill is high, and the power consumption of powder mill is low (because the ratio of the weight of the cylinder to the weight of the mill is small, the work required to overcome the friction is less).Long too short, product fineness difficult to meet the requirements, long too long, increase power consumption, and produce more over grinding phenomenon.The length-diameter ratio of cement industry tube mill is 3 ~ 6.
 

(3) lining plate type and arrangement

The production capacity of the mill is higher when the capacity of the liner is larger.When the grading board is installed, the grinding body in the mill is positively graded, which is beneficial to the improvement of production capacity.When installing the groove lining plate, the steel ball can play the impact grinding function better and the production capacity of the mill is higher.
 

(4) compartment plate and feeding and discharging device

The shape, width and effective section area of the grate in the compartment plate are reasonable, and the mill has a high production capacity when it is suitable for the structure of the inlet and outlet devices.
 

(5) speed

The speed of cement industry tube mill is about 76% of the critical speed.The production capacity can be improved by proper increase of rotating speed, but the power consumption of pulverization will not decrease obviously.Too high rotating speed will cause the vibration of the grinding body intensified, grinding body and lining plate wear increased, the operating rate decreased, resulting in a decline in production capacity.
 

(6) ventilation

When the ventilation inside the mill is good and the wind speed is appropriate, the productivity of the mill is high.Closed circuit is generally 0.3~0.7 m/s, open circuit is generally 0.5~1.2 m/s.

 

2. Material factors

 

(1) hardness of materials

The greater the hardness, the worse the frangibility, the lower the productivity of the mill.
 

(2) granularity

The larger the feed size, the longer the grinding time to the required fineness, the more power consumption, the lower the production capacity of the tube mill.
 

(3) water content:

the total water content of grinding materials should be about 1.0%.High water content, the steam in the mill can not be discharged out of the mill, easy to paste the ball and lining plate, the production capacity of the mill decreased;Too high, the grate will plug and cause "full wear", or even make the mill unable to run.
 

(4) temperature

When the temperature of the grinding material is high, the powder material with electrostatic adsorption and agglomeration, the production capacity of the tube mill decreases.When it is too high, the "ball bag" phenomenon will occur.
 

(5) product fineness

When the product fineness is too fine, the grinding time to the qualified fineness is too long and the grinding phenomenon is intensified, and the production capacity of the mill is significantly reduced.

 

3. Feeding operation

When the feeding amount is appropriate and even and stable, the ball material ratio is maintained in the mill, and the production capacity of the tube mill is high.
 

4. Grinding method

Closed-circuit grinding is more productive than open-circuit grinding.It is also a closed circuit powder mill, with a high efficiency concentrator than with centrifugal and cyclone thing concentrator production capacity is high;The reasonable selection of parameters such as cyclic loading rate is higher than the production capacity when it is not reasonable enough.
 

5.Five other

Mill load control device can increase mill output.The output of mill with pre-crushing equipment is higher than that without.

The page source:https://www.lvssn.com/Product/What-are-the-factors-that-affect-the-production-capacity-of-the-tube-mill-resolved.html

Causes of jaw plate damage of jaw crusher and maintenance methods

Product introduction:https://www.cementepc.net/crusher/Jaw-crusher.html

The jaw plate is the core of the jaw crusher working directly with the material contact.In the crushing material, crushing teeth by the material's extrusion, grinding, impact, bear a huge load, the direct result is that the jaw plate is easy to wear.After the crushing teeth wear out, the power consumption of the crushing station will increase. In serious cases, the equipment will be shut down. Frequent replacement of jaw plate will also affect the benefits.Therefore, we must learn the causes of jaw damage and maintenance methods of jaw crusher.
 

1. Causes of jaw wear and maintenance methods

The main reason of jaw plate wear of jaw crusher is that the material moves relative to the jaw plate in short distance, the cutting metal causes abrasive chips, and the jaw plate repeatedly squeezes the material to cause the jaw plate material to deform for many times, resulting in fatigue chip and wear of the metal material.

1.1 causes of jaw wear

(1) when the machine is running, the material enters the crushing chamber, and the movable jaw is driven by the eccentric shaft to be close to the movable jaw. The two jaws slide with the material relatively short distance, and the material cuts the jaw to form abrasive chips.

(2) moving jaw plate and fixed jaw plate are sometimes close to, sometimes away from, the material is repeatedly squeezed to chisel the two jaw plates, and micro-cracks are formed on the surface of the jaw plate, or at the root of the protruding part of the extrusion metal, and the micro-cracks are continuously extended to connect, causing the metal material on the surface of the jaw plate to fall off and form abrasive chips.

(3) the metal material of the jaw plate is locally fractured or raised due to long-term repeated extrusion of the material by the two jaw plates, and the broken or raised part falls off with the material hit by extrusion, forming abrasive debris.
 

1.2 maintenance method of jaw wear

(1) the material selection of jaw crusher should be high toughness, friction resistance and extrusion resistance of high-performance materials;

(2) the jaw crusher avoids other hard debris entering the crushing chamber during feeding, and cleans the crushing chamber timely after each use.

(3) the machine must be operated in accordance with the specified operation time during use, and the machine cannot be operated continuously for a long time without rest.

2. Causes of jaw fracture and maintenance methods

 

2.1 causes of jaw fracture

(1) the casting process of the jaw plate is not perfect, and there are some serious defects such as intensive porosity inside.

(2) the movable jaw moves in the frame, and one end of the bottom of the frame hits the edge guard plate.

(3) the tension of the pull rod spring fails to be replaced in time.

(4) the discharge port is smaller than the specified range, the feeding position is wrong, and the Angle of the feeding hopper is too steep to make the material directly hit the moving jaw head.

(5) the equipment USES unqualified bracket and bracket pad, so that when the jaw crusher is subjected to strong impact, the bracket does not have self-breaking protection.

2.2 maintenance method of jaw fracture

The internal structure of the two jaw plates is tight due to the excellent casting process.Adjust the size of the feeding port according to the specifications and parameters, continuously and evenly feed the material, and ensure the feeding position in the middle;Replace the rod spring, bracket, bracket pad and other damaged accessories, adjust the Angle of the hopper.

The page source:https://www.cementepc.net/productknowledge/Causes-of-jaw-plate-damage-of-jaw-crusher-and-maintenance-methods.html

Safety problems in the production of new dry cement

Product introduction:https://www.lvssn.com/epc/Dry-Process-Cement-Production-Line.html

NSP cement production technology refers to suspended preheating and precalcining technology as the core, put the latest achievements of modern science and technology and industrial production is widely used in cement production process, the classical tutorial will cement cement craft process summarized as "two grinding burn", namely the limestone and clay as the main raw material, through crushing, ingredients, fine grinding raw materials, feeding in the cement rotary kiln calcining mature material, adding suitable amount of gypsum (sometimes mixed with mixed material or admixture) mill.The safety problems in the production of new dry cement are as follows
 

1. Cement machinery and equipment

The new dry cement production process involves more mechanical equipment, and has the characteristics of large and heavy, mainly conveying equipment, crusher, screw blade, coupling, hoist chain bucket, rotary kiln, mill, etc..If there is no effective protective device for transmission parts and moving parts of these equipment or the production process violates the rules and regulations, it may cause clamping, entanglement, twisting, shearing and other mechanical damage to the personnel on duty.

2. Electrical equipment of cement plant

Electric power system is the main power of the new dry cement production line, and its electrical accidents mainly exist in the substation and the on-site electricity units, the substation potential accidents under certain conditions will cause such as fire, explosion, electric shock, resulting in equipment and property damage.The main causes of electric shock accidents include: personal contact with leakage equipment, accidental contact with live body, approaching high voltage in a less than safe distance, violation of operating rules for live operation and advance transmission, no lightning rod (belt) or lightning arrester (cabinet), etc.
 

3. Storage and collection facilities

In the production process of new dry cement, it is necessary to set up a circular storehouse or a storehouse to measure and store materials for batching.Powder materials, whether coal powder, raw material powder, clinker powder or cement powder, are in a fluid state and stored in a circular warehouse or silo. If personnel fall into it, personal injury or suffocation will be caused, and the material falling into it will damage the batching or feeding equipment at the bottom of the warehouse.The powder materials scattered from the collection and storage facilities are of granular shape, dense and hard, so the operators are easy to slip and fall if they step on them.

 

4. High-altitude operation of bearing facilities

In order to meet the production requirements of batching, conveying, storage, powder selection, dust collection and operation, the corresponding equipment and facilities are arranged on buildings and structures of different heights, such as kiln tail chimney, raw material storage, clinker storage and clinker homogenization storage.In the production operation, personnel inspection, operation, lifting and handling of accessories materials, replacement of materials in the warehouse, and personnel working at the height of walkways, ladders, platforms, etc. If the protective measures are not complete or damaged, personnel operation error, outdoor weather impact, may occur maintenance, inspection personnel fall accident.The accidental fall of an object from high above the ground may also pose a threat to the safety of passing employees on the ground.

 

5. The noise

The equipment that cement factory produces higher noise basically has: break mill, elevator, ball mill, air compressor, ventilator and electric motor.Noise will bring health hazards to the field workers, and long-term work in a high noise environment will cause damage to the human auditory system.Working in a noisy environment, people's attention is not easy to focus, work is easy to make mistakes, not only affect the progress of work, but also easy to cause industrial accidents.
 

6..dust

In the cement production process with a series of production processes will produce large amounts of dust, the crushing, feeding, grinding, conveying, calcination, choose powder, assembly and other major producing dust, if you don't choose the right to control dust, dust collecting equipment is polluting the environment, occupational health and cause serious damage to workers, especially shale dust free SiO2 concentration is higher, comprehensive dust and should be taken to strengthen the combination of dust control of individual protection, prevention of pneumoconiosis.

By analyzing the possible safety problems in the process of the new dry cement production line, it is possible to find the parts where accidents may occur, and trace the causes of accidents according to the specific types of accidents, which can effectively reduce and prevent the occurrence of accidents.At the same time, cement production enterprises should strengthen safety management, safety alarm bell ringing, eradicate paralysis.

The page source:https://www.lvssn.com/Industry/Safety-problems-in-the-production-of-new-dry-cement.html

Maintenance skills of hammer crusher

Product introduction:https://www.cementepc.net/crusher/Hammer-crusher.html

When the hammer crusher is started, the motor will not rotate.If external forces are applied, the motor will rotate but will emit a weak electric sound.At this point, you can think of a leakage of the capacitor.Today to introduce the hammer crusher maintenance skills.

1. The hammer crusher is too loud

If the current sound is too loud, the motor will not start or the capacitor will short-circuit.At this point, have it repaired by a professional maintenance staff.When repairing, if there is no professional maintenance instrument, you can remove the capacitor, plug the two wires into a neutral socket, and connect the cable for charging.Then take out the wire and discharge it.

If an electric spark can be produced, a capacitor can be inherited.If the spark is weak, the capacity of the hammer crusher will be reduced and new capacitors or small capacitors will be needed.However, if the capacitor is damaged, it must be replaced and cannot be treated as described above.

2. Maintenance method of hammer crusher frame to port

For the long term work of the detachable frame, another whole plane of the frame will wear out.In this case, it should be resolved in time.

First, the wear condition of hammer crusher frame is measured, the detailed value of grinding deviation is determined, and then the electric welding planer is carried out.But make sure the center spacing of the original bearing is ensured.

3. Rack crack treatment:

The frame of hammer crusher is an important bearing part, so cracks may appear in the weak part of the frame.If the frame breaks, it can be repaired by welding.The vibration of hammer crusher is intensified during operation, which indicates that there may be uneven wear between the worn parts and the rotor, which is caused by unbalanced state or looseness caused by asymmetric rotor and materials.The pulley.After the normal vibration has been removed, the inspection can be suspended.

In addition, the vibration switch installed on the hammer crusher can be set to take active rest before equipment damage and personal injury occurs when unbalanced vibration is detected.When the crushing and sanding machine is fed, the unbalanced process of about 30~60s usually occurs.In this case, the feed cannot be stopped and increased as much as possible until the vibration is reduced.

The page source:https://www.cementepc.net/productknowledge/Maintenance-skills-of-hammer-crusher.html