Hammer Crusher is composed of rack, rotor, sieve bar, hammer, etc. Motor drives rotor through transmission belt, and materials are crushed due to the collision between hammer and materials produced by the rotation of rotor.
As important mining equipment for the underground coal mine coal transportation system, hammer crusher is usually installed in the middle section of the coal transportation system. Raw coal in the middle of the transportation is crushed into small pieces by a hammer crusher and then transported to the ground coal yard. The coal mine hammer crusher consists of the bottom trough, the crushing frame body, the breaker shaft, the transmission device, the adjusting device and the lubrication system. It has no transfer function and needs to be connected with the crushing bottom trough. The hammer crushing frame body is located at the upper part of the bottom groove, and a crusher shaft is installed in the middle of the frame body. Buy hammer crusher
The mechanism of action is that the broken hammer shaft is lifted to a certain height through the transmission device, thereby increasing the gravitational potential energy. After the falling, the hammer head impacts and squeezes the raw coal at the bottom groove, and is crushed to a smaller particle size, which is convenient for continuous transfer of the transfer machine. The coal mine hammer crusher can adopt two different transmission forms of pulley and reducer according to the power of the equipment. Normally, the pulley drive is only used for hammer crushers up to 250 kW, and hammer crushers larger than 250 kW are driven by reducers.
(1) Design processing defects. The design should ensure that the structure of the equipment is stable and the dynamic characteristics are good. Unreasonable mechanical construction will lead to local stress concentration in the hammer crushers, affecting the dynamic characteristics, and thus may cause undesirable phenomena such as forced vibration or self-excited vibration. (2) Installation, commissioning, and maintenance procedures. In the installation, commissioning and maintenance stages of the hammer crusher, the installation of each spare part may be misplaced. The coordination and installation positions of the shaft system in the transmission system are not suitable, the adjustment of the geometric parameters of the whole equipment is not in place, the installation position of the moving cone is unreasonable, etc., and then It may cause problems such as large equipment load and poor stability of the running state. (3) Human error. In the process of human operation, the equipment is abnormally opened, closed and the speed is not properly adjusted. The hammer crusher runs beyond the design working condition for a long time, the equipment lacks maintenance, and the lubrication between the various components is insufficient. It is also a factor causing the hammer crusher to malfunction. (4) Wear and deformation of the components. The hammer crusher runs for a long time, and various components are prone to different degrees of wear and deformation. Individual parts may be detached, cracked or even damaged by vibration, and the deflection of components such as moving cones may change. Parts may also be pitting or corroded by the external environment, or may wear out with other parts or be affected by vibration. Uneven settlement of the location; at the same time, the gap between the individual parts increases, the looseness of the fit, the friction of the mating surface decreases, etc., which will affect the normal operation of the hammer crushers.
The vibration and moving cone action of the hammer crusher will cause the moving cone to wear, which will cause the center of gravity of the moving cone to shift to form an eccentricity, resulting in an unbalanced moving cone. The problems caused by the imbalance of the hammer crushing motor cone are: (1) The moving cone produces an eccentricity, which changes the force state of the rotor to make it unevenly stressed. During the rotating motion, the moving cone repeatedly bends. When the fatigue limit is reached, damage or even breakage may occur. (2) The moving cone is unbalanced, the equipment is out of the design working condition, and the vibration is caused by severe vibration, which interferes with the external environment. (3) During the working process of the rotor, deflection due to uneven force, friction with bearings or other adjacent components not only causes wear of various components in the equipment, but also affects the working efficiency of the equipment. It is a serious safety hazard and should be strengthened. Inspection and timely disposal.
In a rotor system connected by a coupling, misalignment between the two rotors causes the coupling to deflect, and the bearing that is connected is affected by the rotor misalignment, which shortens the service life, affects the oil film stability of the sliding bearing, and the overall operation of the bearing. Poor, resulting in more serious irregular vibrations. The monitoring of rotor misalignment should be increased, and the vibration amplitude and phase stability should be detected.
The rotor system of the hammer crushers is affected by factors such as rotor misalignment, bending of the shaft, looseness of the foundation, wear of the bearing, improper assembly, etc., and friction or even rubbing phenomenon with the bearing. Although the torque that the rotor is subjected to during operation of the equipment can be balanced, the rotational speed is greatly affected, the rotor system is also unstable, and the overall stability of the equipment is degraded. Main performance: First, the rotor system vibrates, and second, the rubbing has an impact on the rotor itself. The two overlap each other, resulting in more complex adverse reactions, such as phase reverse displacement and axial trajectory diffusion or disorder. In the design stage, in order to ensure the stability of the equipment, the gap between the rotating parts and the adjacent parts is relatively small, and it is easier to increase the probability of occurrence of rubbing.
Hammer crusher is rotating vibration equipment. During operation, the ground bolts used for foundation and fixation vibrate, which can easily cause the foundation sinking and the loosening of the anchor bolt connection. At the same time, the bearing seat will also be loosened by the vibration. The vibration amplitude is larger, mainly in the vertical direction. In order to determine the loosening condition of the foundation and bearing seat, the vibration signals in the vertical direction are detected and compared with the vibration signals of crusher and ground bolt. If the foundation and bearing housing are looser, there will be a great difference between the two kinds of vibration signals, so it should be dealt with in time to avoid accidents.
Hammer crusher is the key equipment for crushing large blocks of raw coal in coal mine, and is an important part of the raw coal transportation system. Design and machining defects, installation, debugging, maintenance process problems and man-made operation errors and structural wear and tear, deformation is the main source of hammer crusher fault, moving cone imbalance, rotating shaft misalignment, rotor rubbing.
Hammer crusher is an equipment that uses impact form crushing materials. The crusher machine divides into a single rotor and a double rotor. The single rotor is divided into reversible and irreversible. The hammer crusher is widely used for fine crushing of medium hardness materials because of its high productivity and easy maintenance. The hammer mill crushers play an important role in the whole stone crusher plant. It will inevitably appear a variety of problems during hammer crusher working. The problems need to be resolved in time once find. This article will talk about 7 hammer crusher common problems and solutions.
Reason: improper bearing design selection. The processing accuracy of hammer crusher parts can not meet the requirements. Poor installation quality. Vibration factors. Poor lubrication, bearing wear and failure. V belt tension is too large. Improper maintenance methods. The environment temperature is too high.
Reason: Not crushing materials enter the hammer crusher machine. Lining fastener is loose and hammer strikes the lining. Hammer or other parts are broken. Solution: Stop and clean up the broken cavity. Check the tightness of the lining board and the clearance between the hammer and the screen. Replace the broken parts.
Reasons: replacement of hammerhead or cone headwear makes rotor static balance counter condition. Hammerhead broken. Rotor unbalance. Pin roll bending, broken. Triangular plate or disc cracks. Anchor bolt lose.
Solution: remove the hammerhead and choose hammerhead according to the weight which makes the total weight of hammer on each hammer shaft equal to the total weight of hammer on its relative hammer shaft. That is the static balance to meet the requirements
The so-called bearing locking is the bearing in the operation of a large number of heat. The heat in a short time can not be dissipated which leads to locking. This phenomenon in equipment as well as the production service site is very common. The specific causes of bearing heat have the following aspects.
Misfit of bearing outer ring and housing bore or bearing inner ring with shaft during assembly. Improper control of bearing heating temperature during assembly. Improper adjustment of bearing clearance during assembly. These three improper assemblies will cause the bearing heat, resulting in the bearing holding dead.
Oil Seal is used to seal the rotating shaft of mechanical equipment with oil seal components, and the cavity is basically static. So the oil seal is also known as the rotating shaft lip seal. For the oil seal with auxiliary lip, the auxiliary lip has the function of dust-proof which prevents the impurity invasion. And in order to prolong the life of the oil seal. The auxiliary lip often has bad lubrication, and the friction force is big which causes the oil seal to dry friction and the damage. So the installation of a double lip oil seal must be between the lips filled with grease.
During the assembly process, if the gauge is not carefully checked, the temperature will rise rapidly after a certain period of time. Bearing outer ring size has been determined by the end cover and the mouth of the bearing seat, the size of the diaphragm sleeve reduced. The size of the inner ring will be adjusted by the round nut, and finally compressed. the axial clearance of the bearing reduced, making it hot during operation.
Bearing Grease should not be too much. If fat amount is too large which will increase the friction Torque, bearing temperature rise. But if fat amount is too small that cant obtain reliable lubrication and dry friction. Generally speaking, the proper amount of grease is 1 / 3 ~ 1 / 2 of the total void volume in the bearing. Therefore, according to the use requirements, regular injection of the appropriate amount of grease.
Check whether the screw is loose, whether the lubrication is good, whether the parts damaged ( parts such as center feed pipe, conical cover, impeller, underflow liner, circumferential guards and jaws, etc.). Repair or replace in time if they worn out. At the same time, the weight, type, and size of the replacement part must be changed according to the original part parameters. It is best to check the equipment before use to ensure the normal operation of the equipment. Do those also can extend the life of the machine, reduce maintenance costs.
Jiangxi Shicheng stone crusher manufacturer is a new and high-tech factory specialized in R&D and manufacturing crushing lines, beneficial equipment,sand-making machinery and grinding plants. Read More
Many cement plants extract limestone by blasting, which often leads to oversized boulders containing a lot of clay and sand. The crusher therefore has to handle feed that contains larger blocks as well as some sticky materials. Our EV Hammer Impact Crusher is a proven, reliable and cost-effective impact crusher that help to overcome these crushing challenges.
In traditional hammer crushers with a top inlet, introducing large blocks in the feed can impede the action of the hammers and block the crusher. Our EV Hammer Impact Crusher, however, competently reduces quarry-size limestone boulders measuring up to 2.5 metres and weighing up to 5 tonnes to mill feed of 25 millimetres. This is a reduction ratio of 1:100 in a single operation. The EV Hammer Impact Crusher features a highly effective two-stage crushing process. Primary crushing takes place by impacting. Secondary crushing takes place by shearing and compression between the impact hammers and the breaker plate and between the hammers and the outlet grate. This ensures that even the smallest particles absorb energy and that no oversized particles leave the hammer impact crusher. The horizontal feed system can also tolerate coarse feed blocks because of its shock-absorbing inlet rollers.
The EV Hammer Impact Crushers throughput capacities range up to 2200 tonnes per hour (tph) with an outlet grate and 2500 tph without an outlet grate. Motor sizes are typically in the range of 500 - 2500 kW.
The hammer rows, which can vary depending on your crushing capacity needs, are arranged to provide complete coverage across the outlet grate. By arranging them in this way, the raw material can be crushed at multiple points increasing overall efficiency.
Adjustment of the spacing between the hammers, breaker plate and outlet grate can be optimised to compensate for hammer wear. Even when the hammers lose up to 30 percent of their original weight, the required product size curve is unaffected.
The adjustable outlet grate gives the EV Hammer Impact Crusher control of the maximum size of the product. The grate ensures a consistent flow to the conveyor and protects it against any sudden impact of material leaving the impact crusher at high speed. The grate also protects other nearby machinery from being damaged during operation.
The hold-up mechanism of the outlet grate generates a crushed product with a relatively high proportion of fines. In this way, more of the comminution work is moved from the less energy-efficient raw mill to the more energy-efficient hammer impact crusher.
The hammer rows are fitted in a staggered configuration to give complete coverage across the outlet grate. This provides several points for crushing of the raw materials, increasing the overall efficiency of the crusher.
The hammers are pivotally suspended from bolts and are symmetrically shaped. This reduces the full brunt from the contact between material and hammers, which protects the rotor and crusher housing. The hammers can easily be turned to reverse the leading and tracing edges for maximum service life.
Equipped with sturdy, replaceable grate bars supported by heavy cheeks, the adjustable outlet grate allows unique control of the mill feed size using hydraulic systems. This ensures a consistent flow to the conveyor. The outlet grate also serves as protection for the conveyor and other machinery such as reclaimers, sluices and mills, against operational upsets and mechanical damage.
A horizontal feed system incorporating one or two shock-absorbing inlet rollers helps to handle coarse feed blocks. The inlet rollers accurately control the feed to the hammer impact crusher and ensure a smooth and even flow of material. Whether one or two inlet rollers are used depends on the method of feeding the crusher.
Bolted-on, wear-resistant plates protect all exposed surfaces, including the adjustable breaker plates, from abrasive feed materials. The inlet rollers of the horizontal feed system consist of a cylinder and a concentric shaft driven by a separate motor. Rubber pads inserted between the shaft and the cylinder make the inlet rollers shock absorbent.
The hammer rotor assembly consists of a heavy-duty, forged shaft with a square cross section and is also fitted with rotor discs. The unique sandwich assembly of the discs is a robust construction, that helps prevent distortion and crack formation.
The top part of the EV Hammer Impact Crusher can be accessed by means of hydraulic cylinders. The supply package includes hydraulically-operated tools for fitting and dismantling of the heavy hammer bolts.
The hydraulic cylinders and tools are served by a mobile hydraulic power unit which can be stored in a separate room when not in use. A lifting yoke facilitates handling of the hammer rows when changing hammers. It also holds them in position when dismantling and fitting hammer bolts.
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Hammer Crusher Application Field Mining, metallurgy, building material, cement, quarrying, gravel & sand making, aggregate processing, recycling, and chemical industry, etc. Suitable Material Limestone, slag, pebble, rock gold ore, salt, concrete, coal, coke and other materials in the primary/secondary crushing and fine crushing operations.
Hammer stone crusher is a kind of equipment that crushes materials in the form of impact. Crushing the size of 600-1800 mm material to 25m or less. Hammermill machine can not only be used in stone crusher plant, sand plant, but also can replace the cone crusher in the mineral processing.
JXSC hammer mill machine that hammerhead adopts a new technology cast which wear-resistant and impact-resistant. The airframe structure of the hammer mill is seal which solves the problems of dust pollution and dust leakage in the crushing workshop. And it is easy to maintain.
1. Hammerhead uses new cast technology which with wear-resistant and impact-resistant characteristic. 2. Can adjust the granularity size. 3. The seal structure that solves the problems of dust pollution and dust leakage in the crushing workshop. 4. The overall design of hammer crushing equipment has the advantages of beautiful appearance, compact structure, few wearing parts, convenient maintenance, etc.
Hammermill crusher mainly rely on impact energy to complete the crushing of materials. When the hammer mill rock crusher works, the motor drives the rotor to rotate at high speed, and the material enters the crusher cavity evenly. The hammerhead with high speed turns impacts and tears the material lead to the materials are crushed.
At the same time, the material from the high-speed rotating hammerhead to the baffle and screen strip in the frame under the gravity effect. The material larger than the size of the screen hole remains on the screen plate and continues to be hit and ground by the Hammer. Then finally through the sieve plate discharge machine until the crusher material size discharge.
The advantages of the hammer: The ratio of crushing is large, generally is 10-25, high up to 50. High production capacity. uniform products. Less over-powder phenomenon. Simple structure, light equipment quality. Simple operation and maintenance, etc. The series hammer crusher products are suitable for crushing all kinds of medium hardness and brittle materials, such as limestone, coal, salt, gypsum, alum, brick, tile, coal gangue and so on. The compressive strength of the crushed material shall not exceed 150 MPA.
The series of crushers are mainly used in cement, coal preparation, power generation, building materials, and compound fertilizer industries. It can crush the raw materials of different sizes into uniform particles for the next working procedure. Reliable mechanical structure, high production efficiency, good applicability.
But the hammer crusher also has some disadvantages, such as the hammer and grate screen wear quickly. When crushing hard materials, they wear out faster. When crushing sticky wet materials, it is easy to plug the screen seam of the grate. Therefore, it is easy to cause shut down, so the moisture content of the material should not exceed 10 %. When milling hard objects, the hammer and lining plate have big wear. And the consumptive metal material is much, often needs to replace the wear-and-tear piece.
Jiangxi Shicheng stone crusher manufacturer is a new and high-tech factory specialized in R&D and manufacturing crushing lines, beneficial equipment,sand-making machinery and grinding plants. Read More
Impact crusher and hammer crusher both use impact principle to crush materials, and the finished material has excellent particle shape. From the appearance, impact crusher and hammer crusher are similar, but they are different in many aspects, so which is better?
Hammer crusher is divided into single rotor and double rotor. The main body is composed of box, rotor, hammer head, impact lining plate, sieve plate, etc. it can directly crush the material with the maximum particle size of 600-1800 mm to 25mm or below.
In contrast, the crushing chamber of hammer crusher is smaller, the impact effect cannot be fully exerted, and the impact crusher is of multi chamber crushing structure, so the crushing is more sufficient.
The plate hammer and rotor of the impact crusher are rigidly connected. The inertia of the whole rotor is used to impact the material (free crushing, impact crushing, milling crushing), so that materials can not only be crushed but also obtain a larger speed and kinetic energy. The plate hammer is used to smash the input material from the bottom to up and throw it onto the upper impact plate.
The hammer head of the hammer crusher is used to crush the material (free crushing, impact crushing), and the speed and kinetic energy obtained by the material are limited. The hammer head striking materials along the material falling direction, with small crushing effect.
The wear of impact crusher plate hammer often occurs on the side that facing the materials, and its metal utilization rate can be as high as 45% 48%. When crushing limestone, the plate hammer of impact crusher is not seriously worn, but when crushing granite (with high hardness, it can be broken by cone crusher), the plate hammer needs to be replaced constantly.
The hammer head of hammer crusher is in a suspended state, and the wear occurs at the top, front, back and side. Compared with plate hammer, the hammer head is more seriously worn, the metal utilization rate of hammer head is about 35%, and the rotor may also be worn.
The feeding chute and the counterattack plate of the impact crusher can be equipped with heating device to prevent the material from binding, so the material with large water content can be crushed and the blocking is not easy to occur.
The impact crusher is not easy to block the material. First, it can be equipped with heating device to prevent the material from blocking due to sticking. Second, there is no grate bar at the bottom. The product size is determined by the gap between the impact plate and the plate hammer. Therefore, when handling the material with too much water content, it can avoid blocking the grate bar when crushing the wet material.
Both of them are suitable for crushing medium and hard materials, but the impact crusher is mostly used as the secondary crushing equipment. While the hammer crusher is mostly used in the cement production line, as the limestone raw material crushing equipment, or as the primary crushing equipment in the sand aggregate plant.
The compressive strength of materials suitable for hammer crusher is within 200MPa, such as coal gangue and limestone, while the compressive strength of materials suitable for impact crusher is within 350Mpa, such as gypsum, coal gangue, limestone, river pebble, sandstone, quartzite, etc. the application scope of impact crusher is wider.
In the market, the frame part of the advanced impact crusher is a three-part structure, which only needs to open the shell at the back of the crusher to replace the plate hammer, impact plate, lining plate and other maintenance operations. Moreover, there are few varieties of vulnerable parts, which is convenient for the purchase and management of spare parts.