introduction about coal crusher

roll crusher with stable performance | fote machinery

Applied materials: coal, pebble, limestone, dolomite, granite, construction waste, pebbles, glass, cement clinker, basalt, iron ore, quartz stone, coal gangue, etc. Its advantages: high capacity, ability to handle wet, sticky feeds.

Roll crusher, as one of the most economical and practical crushers, is designed to handle the first and second crushing of friable minerals and stones such as coal, clay, coal gangue, limestone, slag, cement clinkers, and shale, etc.

According to the number of rollers, the FTM roll crushers can be divided into three types: single roll crusher, double-roll crusher, and multi-roll crusher. And the most common one is double-roll crusher.

Roll crusher is applied more widely than other crushers because of its small volume and cheap price. With the adjustable discharging system, it can be used flexibly in coarse and fine crushing processes of the industries such as cement, chemical engineering, electricity, mining, metallurgy, building materials, and others.

Roll crushers can adjust the wedge device between rollers to control the feed and discharge size of the machine. Also, it is equipped with a spring device to protect the crushing machine and avoid shutdown caused by overload and iron passing.

When the adjustable bolt pulls the wedge upward, the wedge pushes the movable roller away from the fixed wheel, then the gap between the two rollers becomes larger, and the discharge port becomes larger, and vice versa.

The gasket device adjusts the size of the discharge by increasing or decreasing the thickness of the gasket. When the gasket is added, the gap between the two rollers becomes larger, and vice versa.

The unique structure of rollers makes selective crushing of the roll crushing equipment. Since minerals fed are crushed along its internal friable crack, the finished products are uniform with the cube shape.

The minerals are crushed under the force of rollers and machine body, and ores smaller than the gap between roller and machine frame (of single roll crusher) or roller (of multi-roll crusher) will pass directly without repeated crushing.

With the supporting CPU, operators can control roll crushing machines and monitor gaps between rollers, and clean up the crushing cavity through the central control room, which will help save energy of 30% to 50%.

The main working parts of the roller crusher is the cylindrical rollers. The rollers are supported by the fixed and movable bearings, and they are relatively rotating which are driven by the motor. The materials are crushed by the friction of the rotating rollers, and the finished products are discharged from the gap of the rollers.

The spring is used to balance the pressure generated between the rolls. If there are non-crushed materials falling between the two rollers, the compression spring of bearings can be pushed to make a large gap so that non-crushed materials can be discharged immediately.

The quality of the crushers has a great impact on its price. The high-quality equipment will cost more in terms of workmanship, technology, materials, etc. Meanwhile, it will have a long service life, low failure rate, and better performance, and bring more profit to investors.

In 2019, Fote has exported a total of 39 roll crushers to India, Indonesia, Zimbabwe, Vietnam, South Africa, the United States, Pakistan, the Philippines and other countries, mainly for coal, bentonite, rare earth ore, limestone, aluminum, manganese and others.

Exports of mining machinery have been booming in recent years and Fote has already opened markets in Africa, Southeast Asia, etc. Fote Heavy Machinery has supported foreign customers with low-price and high-quality roll crushing equipment, which has been popular among the majority of customers.

In recent years, the Indonesian government has taken actions to improve its infrastructure and promote economic development. As a result, Indonesia's demand for crushers has increased significantly.

The roll crusher produced by Fote has fine finished products and the best effect on sand making for river pebble. Due to its good finished product size, low powder content and low price, it is widely favored by Indonesian customers.

Firstly, Fote Heavy Machinery is a professional manufacturer of roller crushers. In order to improve the company's comprehensive strength, Fote has introduced international first-class production lines on the basis of original techniques.

Secondly, FTM produces various types of crushing equipment that is suitable for crushing, sand making and milling hundreds of minerals, and ensures excellent quality, good performance and low price.

Thirdly, Fote has provided patient and prudential after-sales service and all-round consideration for customers, and actively created high-tech crushing equipment to take the leading position in the international market.

As a leading mining machinery manufacturer and exporter in China, we are always here to provide you with high quality products and better services. Welcome to contact us through one of the following ways or visit our company and factories.

Based on the high quality and complete after-sales service, our products have been exported to more than 120 countries and regions. Fote Machinery has been the choice of more than 200,000 customers.

7 things youd better know about coal double roll crusher machine - hongxing machinery

Roll crusher has a simple structure with a less excessive crushing phenomenon. The tooth shape, size, and arrangement of roll surface can be changed with the properties of the material, and the medium-hard and soft ore can be crushed in medium and fine. And, whats more, the roll crusher equipment is mainly composed of a roller wheel, roller bearing, pressing and regulating device and driving device. Generally, a double roll crusher often crushes aggregate materials by two rolls, it is suitable for medium and soft stone materials, especially for coal materials.

The driving mechanism is driven mainly by two motors, which is dragged to the slot wheel through a triangular belt and rotates according to the relative direction. When the material is broken, the material passes through the roller through the feeding port, which is crushed and broken, and the finished product is discharged under the chassis. In order to be safe, the transmission part should install the safety cover according to the actual situation. Outstanding advantages of coal double roller crushers: Excellent and efficient crushing TEMP effect:The output of Hongxing double roll crusher is 1.5 times of that of conventional crushers, and the particle size of the finished stone is uniform, the size is reasonable, and the dust content is low. Production cost: There is a broken tooth ring on the double roll crusher, and the wear of the double roll crusher sleeve can be replaced to a certain extent, so as to reduce the downtime and the production cost. Safe and stable operation: The limit rectangular hydraulic coupler not only absorbs the impact force at the time of crushing, but also ensures the smooth operation of the machine, and also has the function of safety protection for the machine. Reduce over crushing and wear parts: The dual function of crushing and screening reduces the over-crushing and energy consumption of the material, prolongs the service life, and has the TEMP effect of shearing and stretching crushing. The material is not easy to be blocked : non-equal round, non-meshing, and non-constant speed operation of two rollers and the phenomenon of material blockage of the roller crusher will be reduced.

Roll crusher is also called double roll crusher, which is mainly used for fine crushing operation with ore particle size less than 80mm. The utility model has the advantages of small volume, large crushing ratio, low noise, simple structure, and convenient maintenance. The particle size of the broken material is uniform, the over-crushing rate is low, and the particle size of the finished product is 0.5 40 mm.

The tooth roll crusher is mainlymade upof transmission device, frame part, crushing roller, mechanical spring device, linkage mechanism and so on. It is suitable for coal, metallurgy, mining, chemical industry, building materials, and other industries, and toothed roll crusher is more suitable for the crushing of raw coal (including gangue) in large coal mines or coal preparation plants. The crushing capacity of a toothed roll crusher is large, and the limited distance between motor and reducer to prevent power overload and sensor overload protection, which is safe and reliable.

One of the most simple and intuitive differences between the double roll crusher and the toothedroll crusher is the tooth, in other words, the toothedroll crusher has the tooth, double roll crusher doesnt have the tooth. On the other hand, it is possible to distinguish from the mode operation of the apparatus, the drive mechanism of the roller crusherisdriven by two motors, by means of a triangular belt drive to the sheave, and rotating in a relativedirection. When the material is crushed, the material passes through the roller wheel from the feeding port, is crushed by the rolling, and the broken finished product is discharged from the bottom of the bottom frame.

Hongxing tooth roller crusher adopts special wear-resistant tooth roller to rotate at high speed, and the material is split and broken (the traditional tooth-roller crusher is crushed by low-speed extrusion), and the mechanism of high productivity is formed. The pitch of the toothedroller machine is adjusted hydraulically, and the bearing of the HXJQtoothedroller shaft is lubricated. Generally, the toothed roll crusher has the designof optimization, the tensile shear selection, high-efficiency, low-consumption anduniform discharginggranularity.

Recently, an Indian customer named Jim has come to HXJQ corporation for purchasing double roll crushers, at first, HXJQ coal roll crusher price has surprised him a lot, cause the roll crushers not only has excellent quality but also great advantages (comparing to other roll crushers). After a conversation with our salesman, Jim has adopted the advice raised by the salesman. Additionally, Jim has also seen the worksite of our crushers on HXJQ website.

There are many double roll crusher manufacturersproducing this kind of crusher machine, one of the most popular mining crushers manufactures is China HXJQ. As we all know, Hongxing Machinery offers multiple types of double roll crushers, you can choose your ideal crushers according to double roll crushers catalog. There are many double roll crushers for sale.

coal mining equipment introduction - petroleum refinery equipment for sale,petroleum product,petroleum machinery

In this coal crushing process, coal crusher is the main processing machine. In fact, there are several types of coal crushers. Coal Jaw crusher is the most common crusher equipment in coal crusher plant and used as primary coal crusher. It can crush big coal into small pieces. Impact crusher is another common crusher that is used in coal crushing process. It is mainly used in primary or secondary crushing process. Cone crusher is used as fine coal crusher machine, and used in secondary or tertiary crushing process. Hammer crusher is a coal crusher with small capacity. Usually it is used with coal mill to grind coal into powder. Mobile coal crusher is the convenient coal crusher. It unite the crushing equipment, belt conveyor, and vibrating screen. So crushing and screening process can be finished in this machine. These stone crushers have their own benefits. How to choose which type of coal crusher is used in coal crushing depends on your requirements, such as crushing capacity, the finished size, etc. Coal crusher plant In fact, we rarely use only one crusher in coal crushing process. Usually we compose these coal crushers into a complete coal crusher plant. A complete coal crusher plant includes crushing and screening machines. Jaw crusher is the primary crusher, impact crusher is the secondary crusher, cone crusher is the fine crusher. Raw coal is transported between these coal crushers through belt conveyor. The finished crushing coal materials is screened out by vibrating screen. The eligible coal materials enter into further process, while unqualified pieces return to the coal crusher for crushing again. In this coal crushing process, coal can be crushed into 30-50 mm. If you need coal powder, coal particle is grinded into powder by coal mill. Coal Mill SBM vertical coal mill is a new kind of mill, which is invented by our company chief engineer Mr Bai yinghui, who has been engaged in the research and development of grinding machine for many years. SBM coal mill is the main equipment of coal powder production system of thermoelectric power station, and it is also the essential equipment for drying and pulverizing coal power in cement plant. SBM coal mill can grind coal perfect. This new patent product with high efficiency and low energy consumption opened up an epoch of the international industry pulverizing. The vertical coal grinding mill now sets the standard for coal grinding installations. The coal mill can handle all types of coal and is highly economical in terms of specific energy consumption. Coal crusher manufacturer SBM is a coal crusher supplier in China, and design coal crusher for coal crushing process. With the development of 30 yesrs, our products have formed two main kinds crushers and petroleum equipment service grinding mills. Crushers include jaw crusher, impact crusher, cone crusher, and vsi crusher. Grinding mills include ball mill, raymond mill, vertical mill, and ultrafine mill. We also supply a complete crushing and screening plant, such as stone crushing plant, coal crushing plant, ore crushing plant, concrete crushing plant, construction waste crushing plant and ballast crushing and screening plant. Now our stone crusher machines have export to all over the world, such as Indonesia, Philipines, India, Vietnam, USA, Australia, South Africa, Egypt, Germany, Poland. Coal is the important energy resources and mineral resources in our life. In order to use coal efficiently, we usually crush coal into powder by coal crusher. Author Box stone crusher has 1 articles online

Print article Report Add New Comment Coal Mining Equipment Introduction Log in or Create Account to post a comment. * * Security Code: Change Image Related searches: Coal Mining Equipment Introduction coal chamber plantronics plants processor plantar fasciitis can crusher millsberry crusher joe crushing day bone crusher Related Articles Coal Mining Equipment Introduction Illinois Coal Mining Publisher: Alice Lane The Illinois coal mining boom began during the American Civil War. A farmer near Braidwood Illinois healthcare hit a rich vein of coal while he was digging a water well in 1864. During the half century following this discovery, thousands of workers migrated to Kankakee, Will, and Grundy counties to seek employment in the coal mines. Coal Mining Equipment Supplier in China Publisher: sunshine liu Coal mining Equipment is to remove coal from the ground.Coal is valued for its energy content.Coal mining consists of the removing or extraction of the earths coal which is utilized as fuel. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. Coal mines are in conjunction also known as collieries. There are diverse methods of coal Indonesian Coal Mining 2011 Report Publisher: edi batubara Progress reports from the coal mine business in Indonesia in 2011, this edition will we report in this article. Coal business in Indonesia to grow quite good and has a lot to draw some big investors from countries in europe and asia to invest in coal mining business in Indonesia. An Introduction of Coal Mill Publisher: canales Coal Mill is major equipment of cement plant and used for drying and grinding coal. Introduction to Various Grinding Mills in Mining Publisher: hxjqChina A grinding mill is a kind of equipment designed to break a solid material into smaller pieces. Knowledge of Coal Beneficiation Plant and Mining Equipment Publisher: Sorata King Commercial energy consumption in India has grown from a level of about 26% 68% in the last four width:622px;height:15px;font-style:italic;text-align:center>This article was published on 2010/11/19 You might also like Taylor Swift Shines in her Short-sleeved Gucci Gown on the Red Carpet at the 2014 Grammy Awards

coal crusher, coal crushing machine, coal crusher manufacturer, coal crusher price - ftm crusher company

Since the compression strength of coal is about 5-50, general crusher is able to deal like jaw crusher, impact crusher and roll crusher, etc. However, there exist special requirements for processing and using the coal, thus Fote technically produces a hammer coal crusher.

1. If you have various demands for the particle size of finished products, the Fote hammer coal crushing machine will help you. Hammer coal crusher machine has advantages of high production capacity and finished product is about 35mm, and its adjustable to be changed in different models of primary crushing, secondary crushing and fine crushing.

2. As we all know, the coal is valued and we should use effectively. If the coal is over-crushed, a lot of coal ash will appear. While the hammer coal crusher uses the active forces of hammer to crush coal, you will love this hammer coal crushing machine since it can reduce the appearance of coal ash.

3. If you are in the field of coal crushing, you must be troubled with the coal with high water content. While the hammer coal crusher machine can crush both dry and wet coal. It is completely suitable to the open-pit mining work.

If you need the latest price list, please leave us a message here, thank you! We guarantee that your information will not be divulged to third parties and reply to you within 24 hours. Tell us your needs, there will be more favorable prices!

coal crusher, broken coal machine, co

Coal is a kind of solid combustible mineral which is formed gradually by the complex biochemical and physical chemical changes of ancient plants buried underground. It is a kind of solid combustible organic rock, which is mainly formed by the biochemical process of plant remains, buried and then transformed by geological process, commonly known as coal. According to the different primitive materials and conditions of coal formation, natural coal can be divided into three categories, namely humic coal, residual coal and sapropelic coal. Coal is the most widely distributed fossil energy resource in the world. It is mainly divided into bituminous coal and anthracite, sub-bituminous coal and lignite. Sixty percent of the world's recoverable coal reserves are concentrated in the United States (25 percent), the former Soviet Union (23 percent) and China (12 percent). In addition, Australia, India, Germany and South Africa account for 29 percent of the world's total coal production. The above-mentioned seven countries or regions account for 80 percent of the world's total coal production. The proven coal reserves are more than 63 times the oil reserves. Abundant countries are also major producers of coal.

After crushing, the coal can be used as an additive or internal fuel. Vanguard's coal crusher is a new type of European coal mine crusher which absorbs the latest international crushing technology and combines with the domestic market demand. The coal breaker is suitable for crushing many kinds of ores with different hardness. The crushing fineness can be adjusted to different grades of coarse crushing, medium crushing and fine crushing, which perfectly realizes the various requirements of coal crushing for particle size. Coal crusher equipment commonly used in coal crushing includes: jaw crusher, impact crusher, circular vibrating screen, according to special requirements can also be added sand machine and other equipment, in order to achieve a more refined treatment of coal. Vanguard's coal crusher is a kind of high-efficiency and wear-resistant coal mine crusher. It has the characteristics of simple structure, high crushing ratio and high production efficiency. It can be used for dry and wet crushing. It can also adjust the gap between the castor bars according to the requirements of users and change the size of the discharged material to meet the different needs of different users. In addition, the coal crusher not only has high production efficiency, but also the hammer head of the self-developed coal mine crusher is very wear-resistant, customized processing is very convenient, greatly reducing the trouble of frequent replacement of vulnerable parts. Coal has a wide range of uses, which can be summarized as three main uses according to its purpose: (1) power coal, (2) coking coal, (3) coal for coal chemical industry, mainly including gasification coal, low-temperature dry distillation coal, coal for hydroliquefaction, etc. Power coal includes power generation coal, steam locomotive coal, building materials coal, general industrial boiler coal, domestic coal, metallurgical power coal and so on. The main use of coking coal is coking, coke is made from coking coal or blended coal smelting at high temperature, generally 1.3 tons of coking coal can be converted into a ton of coke. Coke is mainly used in steelmaking. It is the main raw material for iron and steel industry. It is known as the "basic food" of iron and steel industry.

coal crusher-china hxjq mining machinery

Coal crusher is professionally designed for the primary and fine crushing of coal materials such as coal, coal gangue, lignite, coke,etc. The crushed coal can be used as fuel or power in many industries.

We also has full coal crushing screening plant for sale. You can choose the proper one according to your needs. If you are new in this industry, we will provide professional solutions and suggestions for you.

We also have other types coal crusher for choice, including mobile crusher, impact crusher, hammer crusher. Mobile crusher is featured with high mobility, which is suitable for medium and large sized production.

In addition to coal crusher,we also provide coal grinding mill for coal powder grinding. Generally, we have two types of coal grinding mill for choice. Ball mill can be used for wet and dry grinding of coal, Raymond mill is used for dry coal powder grinding.

Please feel free to fill in the following form or email us ([email protected]) to get product information,price,service and other supports.We will reply to you within 24 hours as soon as possible.Thank You!

coal crusher-zhongde heavy industries

1.Coal crusher is the commonly used crusher machine for the primary and fine crushing of coal materials such as coal, coal gangue, lignite, coke,etc. Double roller crusher is the most popular coal crusher in the market because of its unique structure and high crushing efficiency.

2.Abbout the commonly used coal crusher, we have hammer crusher,roller crusher and mobile crusher for choice. Hammer Crusher and roller crusher are suitable for the small scale coal crushing;while the mobile crusher is widely used for medium and large scale coal crushing. Each type of coal crusher has full models for sale.

coal crusher types- impact& double roller crusher

Coal crusher, also known as double stage crusher, is a highly efficient crushing equipment. It is a new type of equipment developed for the coal industry, and it mainly crushes high moisture coal. Besides, it is mainly used to crush coal cinder, slag, shale, coal gangue and other materials. And it can be applied to building material, highway, railway, mining and other industries.

This type of crusheris better than traditional crushing equipment. Once the material moisture content is more than 8%, the traditional crusher will be blocked and the motor will be burned. Fortunately, Aimixs coal crushing and screening plant can solve the problem. The biggest advantage of Aimixscoal crusher is that it can also have normal production even on rainy days. Even the moisture content of the material is high, the material will not be blocked when it is crushed, because itdoes not have a sieve bottom. Besides, the crushed material of the crusher is very uniform and can be controlled below 2 millimeters, and the traditional machine crusher must add a sieve to screen out the ideal product size.

The crusher has two sets of rotors which connect with each other. And when the itworks, the two rotors rotate at the same time under the drive of two motors. In the crushing cavity, materials which be crushed by the first rotor will be crushed immediately by the second rotor again. Materials in the inner cavity will collide and smash each other rapidly. That means the materials will be crushed by the hammer and other materials. After crushed, materials will be discharged. And this is the working principle of a coal crusher plant. PF1010impact-crusherModel: PF-1010 Specifications(mm): 1000*1050 Diameter of feeding inlet(mm): 400*1080 Max. feeding Aggregate Size(mm): 350 Capacity(t/h): 50-90 Power(kw): 4P 45-55 Total weight(T): 12 Dimension(L*W*H)(mm): 2370*1700*2390

1. Without the screen and grate, Aimix coal crusher for sale can crush high humidity materials. And the crusher has no any requirement for materials moisture content. At the same time, it can also crush dry materials. Besides, ithas large output, small noise, and high crushing efficiency.

2. Thecrusher adopts the new type shift clearance technique. The worn hammer of the crusher does not need to be replaced, because the position of the hammer can be adjusted. As long as the gap between the hammer and the liner is appropriate, the finished material size will be uniform. In addition, the lining board is also adjustable. So, in general, a hammer of thecrusher can replace three ordinary hammers. Moreover, the service life is much longer than that of traditional crushing equipment.

3. The coal crusher machine has centralized lubrication system, that means oil can be injected without stopping machine. In addition, it uses hydraulic system to open the shell, and the shell can be easily opened by one people. Both machine maintenance and spare parts inspection are very conveniently.

As a professional crusher supplier, Aimix has various type of coal crushers and other impact rock crusher machines for sale. In order to meet the needs of different customers, we have developed and produced many types of crusherequipments. In addition, we have different kinds of coal crusher specifications.

As for the type, we have several series, such as ZPC series, HD series, the third generation SCF series and so on. The main situation of these crushers are same, but they have small differences. You can ask us online for more detailed informations.

In addition, every type of crusher has many specifications. For example, SCF crusher has various specifications: SCF600*400, SCF600*600, SCF700*800, etc. The same point is, the water content of the crushed materials should be less than 25%. But their input size and output size are different. You can choose different type or specification of crusher to meet your actual needs. You can contact us if you have any problem, Aimixs expert will give you the best solution.

You can find more product informations on our companys website. Chat with us online or send us an e-mail, and we will give you the most professional answer. Moreover, we can customized all types of crushers and other mobile crushing plants. We have our own factories and technicians to design and produce all the equipments. We ensure that we will give you the best price and high quality product!

5 common faults analysis of coal hammer crusher

Coal hammer crusher is important equipment for crushing large raw coal. Its stable operation plays an important role in ensuring the raw coal conveying efficiency of the underground coal mine. We can put forward the corresponding solutions via analyzing the main fault sources and common faults of coal hammer mill crushers. Then improve the hammer coal mill crushers operation reliability, reduce the maintenance difficulty, and make sure the smooth progress of coal mining.

According to the working principle, coal crusher can be divided into two types: hammer crusher and jaw crusher. The hammer mill crushers have large processing capacity that max capacity is 4000tph. So the coal plant mainly uses hammer crushers to crushing raw coal. The power of the hammer crusher general is 90 ~ 400kw, which mainly depends on the rotating parts to drive the hammer up. Then crush the lump coal to the particle size which is easy to transport by the impact force of the hammer falling.

As important equipment of the underground coal mine transportation system, a coal hammer crusher is usually installed in the middle of the climbing section. The large piece of raw coal is transported to the transfer machine by the scraper conveyor and then guided into the hammer crusher by the transfer machine. The coal is crushed into small pieces by a hammer coal crusher and then transported to the ground coal yard.

The coal hammer mill crusher is composed of a bottom groove, crushing frame, hammer shaft, driving and adjusting device, and lubricating system. It has no transshipment function which needs after connecting the crushing bottom groove and connecting slot. Then uses the transshipment machine. The hammer impact crusher frame body is located on the upper part of the bottom groove and installs a crushing hammer shaft in the middle of the frame body. The mechanism is that the hammer shaft is lifted to a certain height through the transmission device which increases the gravitational potential energy. After falling, the hammerhead impacts and squeezes the raw coal at the bottom trough, crushing it to smaller particle sizes. The small coal particle is convenient for continuous conveying by the transfer machine.

According to the power of the equipment, the underground coal hammer crusher adopts two different transmission forms: pulley and retarder. In general, the belt pulley transmission is only used for power below 250kw. The power greater than 250kw is through the reducer.

Analyze fault for the large-scale, high-power hammer mill crusher, it cant diagnose specific faults. If the equipment fault is considered to be caused by the damage of a single component, the diagnosis is too one-sided. The test results may be biased, and the subsequent maintenance of the equipment may not achieve the desired repair effect. Therefore, the failure of a high-power hammer crusher should be considered from various factors, such as the design, processing, installation, commissioning and use.

The design should ensure the stability of the structure and the good dynamic characteristics of the equipment. The unreasonable mechanical structure will lead to the local stress concentration and affect the dynamic characteristics of the equipment. Then they may lead to forced vibration or self-excited vibration and other undesirable phenomena. In addition, the common design and manufacture defects include working speed and the material of the spare part can not meet the design requirements, machining accuracy is too low, poor moving cone balance performance, etc.

The hammer crusher installation, commissioning and maintenance stage may occur crusher parts installation dislocation. The transmission system with the shafting and installation location is not appropriate. The overall equipment geometric parameter adjustment is not good. The installation position of the dynamic cone is not reasonable. All the problems may lead to the equipment large load and poor stability in operation.

In the process of man-made operation, the equipment abnormal opening, closed and adjusted speed improperly. The equipment operated beyond the designed working condition for a long time. Lack of maintenance. Lubrication between the components was insufficient. These also cause the failure of the hammer crusher.

The coal hammer crusher operates for a long time, the parts are easy to wear and deformation. Individual parts may be shaken off, crack or even damage. The dynamic cone changes, spare parts will also be affected by the external environment caused by pitting or corrosion. Or with other parts wear each other. Or affected by vibration which causes uneven settlement of the ground where the equipment is located. At the same time, the increase of clearance between some spare parts, losing fit surface and lowering of fit surface friction will affect the normal work of the hammer mill.

The vibration and the movement of the dynamic cone in the operation of the hammer crusher will cause the dynamic cone ware. Then lead to the eccentricity of the center of gravity of the dynamic cone and the unbalance of the dynamic cone. The problems caused by the unbalance of the movable cone are as follows:

In the rotor system which connects with coupler, misalignment between the two rotors will cause the coupler to deflect. The bearing affected will shorten the service life, affect the stability of oil film, the operation is not smooth. We should increase the monitoring of rotor misalignment faults and focus on the detection of vibration amplitude and phase stability.

The rotor system is affected by factors such as misalignment of the rotor, bending of the shaft, loosening of the foundation, wear of the bearing, improper assembly, etc. It will rub-impact with bearings. Although the torque of the rotor can be balanced when the equipment is running, the speed is greatly affected. The rotor system is unstable, and the overall stability of the equipment decreases.

The main performance: one is the rotor system vibration, the other is the impact of rub-impact on the rotor itself. The combination of the two results in more complex adverse reactions, such as phase reverse displacement and axial trajectory diffusion or turbulence. 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 the probability of the rub-impact phenomenon is more easily increased.

Oil Whirl is a phenomenon that the rotor of the transmission system moves the wedge oil film around the center of the bearing bush according to the average velocity of oil due to vibration and rotation fluctuation. The main characteristics are the smooth phase. It is obviously affected by lubricating oil characteristics. The trajectory presents a double ring ellipse. The subharmonic generated by the vibration will change with the increase of the rotational speed.

Hammer crusher is rotating vibration equipment. The foundation and fixed foundation bolt vibration during the crusher machine operating. It is easy to cause the bolt loose. At the same time, the bearing pedestal will be loose because of vibration. Vibration amplitude is large, mainly acting in the vertical direction. In order to determine the foundation and bearing pedestal looseness, the vertical vibration signals are detected and compared with the vibration signals of crusher and foundation bolt. If the foundation and the bearing seat are looser, there will be a big difference between the two vibration signals, which should be handled in time to avoid accidents.

The coal hammer crusher is the key equipment for crushing large raw coal in the underground coal. The machine is an important part of the raw coal transportation system. The common problems are design Defects, installation, debugging and maintenance problems, parts wear and deformation, movable cone unbalance, rotor rub-impact, shaft misalignment, etc.

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

vibration test and shock absorption of coal crusher chambers in thermal power plants (i): field test and assessment

Lihua Zhu, Hanquan Yuan, Haoyi Zhou, Dong Jiang, Baoquan Liu, Chunzhu Fan, Liujiu Tang, "Vibration Test and Shock Absorption of Coal Crusher Chambers in Thermal Power Plants (I): Field Test and Assessment", Shock and Vibration, vol. 2020, Article ID 8816829, 10 pages, 2020.

A field vibration test was conducted on the coal crusher chamber of a thermal power plant to evaluate its vibration performance. The vibration displacements and velocities of the structure, coal crusher body, and vibration-isolation platform were tested. The vibration safety of the coal crusher chamber and the vibration-isolation efficiency of the spring vibration-isolation system were evaluated based on the test results, and the reason the vibration exceeded the limit was analyzed. This study showed that the vibration displacement of a coal crusher with a spring vibration-isolation system met the code requirements, but the equipment had greater vibration displacements, which were related to the connection between the equipment and the platform. Compared to a steel platform, the vibration displacement of a concrete platform was smaller, and the vibration-isolation efficiency was greater. The vibration displacements of the coal crusher body could be reduced by controlling the vibration displacements of the platform.

Coal crushers are important auxiliary dynamic machines in thermal power plants and are used for crushing and processing raw coal. However, a coal crusher generates large vibrations when crushing coal blocks, which can affect the equipment itself, as well as the safety of the structure [1, 2]. Although there have been few studies on the vibrations caused by coal crushers, the research done on the vibrations caused by similar dynamic machines can be used to study them [36]. Liang conducted a static analysis, dynamic analysis, and vibration control analysis of a crushers foundation and discussed the main factors affecting the dynamic response of the dynamic machines foundation [7]. However, only the foundation model of the crusher is established and applies the disturbing force of the crusher onto the foundation of the dynamic analysis, which is different from practical engineering. Liu et al. regarded the dynamic machine foundation and its surrounding structures are considered as a complete coupling object and proposed a three-dimensional finite element method for calculating the dynamic response of a large machine based on soil-structure interaction, and the main factors affecting its dynamic response are discussed [8]. Similarly, Zhu et al. considered the mill and its foundation as a coupled system and conducted vibration performance tests and evaluations of medium-speed mills in thermal power plants [9]. The results showed that a spring damping system could effectively reduce the transmission of the mills vibration to the outside. So far, researchers usually use field tests and numerical analysis methods to study the structural vibrations caused by machine vibration [10]. Wang et al. determined the cause of vibrations using a field vibration test and numerical analysis in a plant [11]. On the basis of this numerical analysis, a method for secondary vibration isolation and reinforcement was proposed to provide a reference for reducing the vibration and reinforcing existing structures to withstand abnormal vibration.

Gazetas believed that the basic goal of dynamic machine foundation design was to reduce its vibration amplitude to ensure safe operation and avoid affecting work on nearby equipment [12]. This guiding ideology has been adopted by the design codes of most countries in the world. Most of the engineering technicians in China address the structural vibration problems caused by dynamic machines based on the guidance provided by the Code for design of dynamic machine foundation (GB 500401996) [13] and other specifications. In practical engineering, many engineering technicians use two methods to reduce structural vibration: increasing the rigidity and quality of the coal crusher chamber and machine foundation and using a coal crusher vibration-isolation platform. Because the vibration of the coal crusher chamber is very complicated, even if these two design countermeasures are adopted, the vibration problem still exists for the coal crusher chamber. Even when using the same design scheme and machine parameters, the vibration problem for the coal crusher chamber is more prominent in some power plants, whereas other vibrations are very small. This problem has always puzzled designers. In-depth research is needed to understand the structure of the coal crusher chamber and the vibration behavior of the coal crusher further.

In this study, vibration tests were performed on coal crusher chambers in three power plants, and the safety of the equipment and structure was evaluated based on the test results. In addition, the vibration-isolation efficiency of the spring vibration-isolation system was calculated. These data provided a basis for finite element modeling.

In general, the coal crusher chamber of a thermal power plant utilizes a four-story reinforced concrete frame structure. The first story is the pipeline layer, the second story is the coal crusher layer, the third story is the vibrating screen layer, and the fourth story is the coal handling layer, as shown in Figure 1. The coal crusher system is composed of the coal crusher, motor, and hydraulic coupler. It is located on the second story of the coal crusher chamber and is connected to the coal crusher chamber through the spring vibration-isolation system, as shown in Figure 2. The spring vibration-isolation system consists of a vibration-isolation platform and spring vibration isolator, in which the vibration-isolation platform can be either a concrete platform or a steel platform. Compared with a concrete platform, a steel platform has a smaller volume, lighter weight, and higher cost. The spring vibration isolator is an elastic element between the machine and the support structure [14]. This elastic element is composed of a spiral steel spring with damping treatment, which is designed to reduce the vibration or impact force from the machine to the support structure. Generally, the spring vibration isolator is used with a viscous damper to prevent the vibration amplitude of the machine from being excessive when starting and stopping.

Three coal crushers in the Linyou, Shangluo, and Ezhou power plants in China were tested to investigate their vibration performances. These three plants all used the spring vibration-isolation system for their coal crushers. Steel platforms were used for the coal crushers in the Linyou and Shangluo power plants, and a concrete platform was used for the coal crusher in the Ezhou power plant. The primary parameters of the coal crusher systems and vibration-isolation platforms are listed in Table 1.

The primary instruments used in this test included 941B vibration pickups, an amplifier with a frequency response range of 0.5100Hz, and an INV306 intelligent signal collecting and processing analyzer. The analysis and processing of the collected data relied on the DASP program.

A modal test of the coal crusher chamber, vibration test of the structure and machine, and vibration-isolation efficiency test of the spring vibration-isolation system were performed. The modal test of the structure used the pulsation method to determine the natural frequency of the structure by placing horizontal vibration sensors on the first floor, second floor, third floor, fourth floor, and the roof, as shown in Figure 3. Five measurement points were also used to determine the vibration displacements and velocities of the structure and machine. Among these, TP1 was a measurement point on the floor slab located near the coal crusher. TP2 was the midpoint on the long side of the top of the coal crusher. TP3 was the midpoint on the short side of the coal crusher, and TP4 and TP5 were measurement points on the vibration-isolation platform, as shown in Figure 4.

After considering site conditions, the layout characteristics of the spring vibration isolator, the measurability of the desired data, and the dynamic characteristics of the crusher, there were eight groups of spring vibration isolators tested (AH), as shown in Figure 5. In the coordinate system of the coal crusher chamber, X represents the transverse direction, Y represents the longitudinal direction, and Z represents the vertical direction.

Modal tests were conducted after the coal crusher was shut down, and the natural frequency and damping ratio were measured using the vibration sensors. The data were analyzed in the frequency domain using the DASP program, and the results are listed in Table 2.

As listed in Table 2, the first-order frequency in the horizontal direction was 0.9871.625, and the second-order frequency was 2.5873.012. The natural frequencies of the coal crusher chambers of the three power plants were relatively similar, which was a result of their similar structures. The measured value of the damping ratio was smaller than the value suggested by the code. Thus, the code suggested that a value of 5% could be used in the dynamic calculation.

Vibration tests were conducted during the steady operation stage of the coal crusher, with the vibration displacements and velocities measured using the described transducers. During the field test, it was found that the vibration amplitude of the coal crusher body in the Linyou power plant was very large. The noise in this plant, which included whistling caused by the crusher, was the largest of the three power plants. Serious powder leakage and large amounts of dust were also noted. The vibrations of the ground and platform in the Shangluo power plant were not serious, and only a small amount of dust was found. The vibration amplitude of the coal crusher body in the Ezhou power plant was the smallest; there was basically no powder leakage, and the plant was very clean. The test assumed that the vibrations of the floor, crusher body, and vibration-isolation platform were stable random processes and that the collected samples could reflect the vibration characteristics. Figure 6 shows the typical vibration curves of the coal crusher chamber, and the maximum value of the vibration is listed in Table 3. The test data provided a reference for the numerical analysis reported in part of this series of papers.

As listed in Table 3, the vibration displacement of the coal crusher body in the Linyou power plant was quite different from those in the other two power plants. This may have been due to differences in the design, manufacture, and installation of the machine body, which should be considered comprehensively.

The Code for design of dynamic machine foundation (GB 50040-1996) and Technical code for the design of civil structure of fossil-fired power plant (DL 5022-2012) [15] specify the following in relation to the maximum allowable amplitude for the coal crusher foundation: when the rotational speed of the machine, n, satisfies n>750r/min, the allowable value in the vertical direction is 100m, and the allowable value in the horizontal direction is 150m. When 300r/min

The speed of the three coal crushers in this test was 743r/min. Based on this, the maximum vibration displacements at the foundations of the coal crushers in the Shangluo and Ezhou power plants were all less than the allowable values. Thus, they all meet the vibration safety requirements. However, the maximum vertical vibration displacement of the coal crusher in the Linyou power plant was 219.39m, which exceeded the allowable value and did not meet the vibration safety requirements. The measurement point on the floor was near the coal crusher to determine the maximum vibration response of the floor slab near the coal crusher. These values for the three power plants were all less than the allowable value, which met the vibration safety requirements.

The lack of relevant guidelines on the vibration displacement of the machine body made it difficult to assess its safety. The maximum horizontal vibration displacement of the coal crusher body in the Linyou power plant was 391.37m, and the maximum vertical vibration displacement was 554.82m. The maximum horizontal vibration displacement of the coal crusher body in the Shangluo power plant was 149.09m, and the maximum vertical vibration displacement was 164.75m. The maximum horizontal vibration displacement of the coal crusher body in the Ezhou power plant was 71.36m, and the maximum vertical vibration displacement was 75.38m. It was found that the vibration displacement of the coal crusher body in the Linyou power plant was 2-3 times the vibration displacement of the top surface of the foundation. This difference was too large, and the horizontal vibration displacement of the foundation exceeded the limit. This indicated that the rigidity of the connection between the machine body and the platform was insufficient, and the vibration displacement of the machine body was too large. This could cause fatigue damage to some rigid connections in the coal crusher. Moreover, the service life of the crusher would be shortened. This is one of the reasons for the serious powder leakage of the coal crusher. The vibration displacements of the coal crusher body and platform in the Shangluo and Ezhou power plants were close, indicating that the rigid connection between the coal crusher and platform in each plant was good. The vibration displacement of the coal crusher body and platform in the Ezhou power plant was smaller than that in the Shangluo power plant, indicating that the vibration displacement of the machine body could be reduced by limiting the displacement of the vibration-isolation platform. Compared to the steel platform, the vibration displacements of the machine body and concrete platform in the Ezhou power plant were smaller. This was mainly related to the greater weight of the concrete platform.

The vibration-isolation efficiency can be regarded as the amount of reduction in the machine vibration passed to a structure under a deterministic simple harmonic forced vibration load. It can be measured using different indicators, including displacement, velocity, acceleration, and force. According to the Design code of vibration isolation of auxiliary machine foundation in fossil fuel power plant (DL/T 51882004) [17], a vibration-isolated foundation is assumed to be a system with a single degree of freedom. The vibration-isolation efficiency can be calculated using the machines disturbance frequency and the natural frequency of the vibration-isolation system. However, the calculation formula for the vibration-isolation efficiency does not include factors such as the displacement, velocity, and acceleration, making it difficult to measure the vibration-isolation efficiency when the machine is running. In order to facilitate on-site measurements, this test measured the vibration-isolation efficiency based on the degree of attenuation of the dynamic response before and after the vibration isolation [18].

In this test, the working frequency of the coal crusher was 12.38Hz (743r/min), which was an intermediate frequency vibration [19]. Therefore, the velocities of the spring vibration isolator were used to calculate the vibration-isolation efficiency:where V1 is the upper velocity of the spring vibration isolator and V2 is the lower velocity of the spring vibration isolator.

The vibration-isolation efficiency of a single spring vibration isolator could be calculated using equations (1) and (2). Then, the vibration-isolation efficiencies of multiple sets of spring vibration isolators were calculated and averaged to obtain the vibration-isolation efficiency of the spring vibration-isolation system. The results are listed in Table 5.

The Technical code for the design of civil structure of fossil-fired power plant (DL 50222012) [15] stipulates that if the vibration-isolation efficiency of a spring vibration-isolated foundation is greater than or equal to 90%, the support structure below the vibration isolation device of a coal crusher does not require dynamic calculation. The design value of vibration-isolation efficiency for the coal crusher systems in the three power plants was 90%. As seen in Table 4, the vibration-isolation efficiencies of the three power plants did not meet the code requirements. The vibration-isolation efficiency of the spring vibration-isolation system used in the Linyou power plant was the lowest, which was closely related to the connection between the platform and the machine. Compared to the other two power plants, the spring vibration-isolation system used in the Ezhou power plant with a concrete platform was more efficient. The construction of a finite element model of the coal crusher chamber is recommended for a dynamic analysis.

In this study, the vibration behaviors of the coal crushers in three thermal power plants were investigated using field tests and assessments. The major conclusions are summarized as follows:(1)The tested coal crusher foundations met the vibration safety requirements, except for the vertical vibration displacement of the coal crusher in the Linyou power plant. The vibration displacement of the coal crusher in the Linyou power plant was too large, and the rigidity of the connection between the machine body and the platform was insufficient, which could result in fatigue damage to some rigid connections in the coal crusher. Moreover, the service life of the crusher will be shortened. Therefore, it is recommended that the connection rigidity be increased.(2)The vibration-isolation efficiency of each spring vibration-isolation system could be measured using the dynamic responses of the upper and lower ends of the spring. This method was simple and easy to implement.(3)Although there is a lack of relevant guidelines on the vibration displacement of a machine body, controlling the vibration displacement of the platform could be used to reduce the vibration displacement of the coal crusher body. Compared to the steel platform, the vibration displacements of the concrete platforms were smaller, and their vibration-isolation efficiencies were greater. The construction of a finite element model of a coal crusher chamber is recommended for a dynamic analysis.

Copyright 2020 Lihua Zhu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

crusher | definition | crusher selection and types of crusher | engineering intro

The crusher is a machine that is designed such that to reduce the size of large rocks into smaller rocks like gravels. It is not only for that, but it is also used for recycling of the waste materials. Crusher is a multi-dimensional machine. Crusher has the ability of changing the form of material. In rock ores, crusher is used for the reduction in size or for making pieces of a solid mix i.e., composed of different raw materials and these pieces are used for the composition study of different raw materials.

Selection of crusher is quite a complicated process because of the availability of many kinds of crusher in the market. So, during selection keep following points in mind and find whether the crusher is able to do these specific functions or not.

If someone selects a crusher that has more capacity than his requirements, then it will be uneconomical. This is so because as crusher size increases, its fuel burning rate and maintenance cost will be more.

Primary crusher has the ability to receive the crushing material (a material that has to be crushed) directly from the source i.e., quarry thats why these types of crusher are fixed from where the material is taken. Primary crusher is only for the breaking of large stones into pieces (this mean primary crusher is not for the aggregate size material.). Examples of primary crushers are jaw crusher; hammer mill crusher and gyratory crusher. After receiving primary crusher crush the material and produce a new fresh reduce size of the source material. Primary crusher has only functioned up to that point.

Now a secondary crusher comes into action and further reduces the size. In secondary crusher some sizes of stones may pass directly from sieve number 4. Examples of secondary crushers are cone crusher, roll crusher and hammer mill crusher.

At the end tertiary crusher reduces the size of crushed pieces very much to the required size and it also brings the fineness to the crushed material. Tertiary crushers are at the job site andthese are small in size. The material is first transported from source with the help of a dump truck. Some tertiary crushers are roll crusher, rod mill crusher and ball mill crusher.

modeling of coal breakage in a double-roll crusher considering the reagglomeration phenomena - sciencedirect

To represent the particle behaviors and to predict the product size distributions of coal breakage products by a double-roll crusher, a new combined breakageagglomeration model has been constructed. The model utilizes a fair combination of individual models for two distinct phenomena, the breakage and the agglomeration which occur simultaneously in the double-roll crusher process. Thus, it is capable of representing the complicated reduction and growth in the particle size during the process. Model parameters were estimated from experimental data from single-size crushing tests. Using these parameters, product size distributions with distributed-size feed were predicted from the simulation and were compared to the experimental results. The simulated results show fairly close agreement with the experimental results with an acceptable degree of accuracy. The basic concept can be used for a description of the simultaneous breakageagglomeration process, which involves particle shape changes during the process of agglomeration.

A combined breakage-agglomeration model has been developed. Agglomeration takes places as the gap of the roll crushers is reduced. Shape of agglomerates was considered in the development of the dual-size model. Agglomeration probability was deduced by considering the rate of compression. The proposed model is potentially applicable to various types of mills.