Defects of Current China Cone Crushers and Their Future

Cone crusher is the main crushing equipment of rock materials, and it is widely used in metallurgy and mining industries. However, the domestic rock cone crusher hasn’t developed too much since the successful imitation in twentieth century. The technique is staying in the first and second generation level of foreign countries. Besides, the domestic cone crushers are too conservative, heavy with low efficiency, high energy consumption and low crushing quality. Therefore, hard working should be done to improve the performance of China cone crusher.
Encircling in order to improve working performance of the cone crusher, and based on research basic results of Evertsson who is a scholar of Chalmers University of Technology, the research was expanded from various eyes of crusher working mechanism and working performance, and several researchs were finished, including crushing mechanism, crusher capacity model, chamber design model, crushing product grain size distribution model and multi-objective optimization model and so on. The paper mainly included these research contents as follows: The significance of chamber optimization design and improvement working performance of cone crushers was discussed after analyzing home and overseas situations of study on cone crusher. Kinetic characteristic of spreading and granular materials in crushing chamber was deeper studied and three different forms of particles flowing state, that is sliding, free-falling, sliding and free-falling state of coexistence were discussed in this paper. Moving track model of spreading and granular materials in crushing chamber was built up by analyzing the effect of moving state to working performance of cone crusher.
The calculation model of crushing product size distribution of rock based on the overall balance model was built up after analyzing the effect of chamber to product size distribution of rock. A new formula calculating production capacity Q was put forward after taking into account fully the effect of volume filling rate at level section to production capacity. For researching and developing of high-performance laminated cone crusher, multi-objective optimization model about production capacity, crushing product size distribution and chamber based on researches of working mechanism and working performance was built up.
In order to further improve the working principles and performance of cone crusher, according to its shortcomings, more research aims, methods and content should be done. The result of the researches can be used to research and develop automated, highly efficient, energy-saving and environmental friendly modern cone crushers.

The Steps of the Transformation of Flotation Machines

Comparing between the BF flotation machine and the traditional flotation machine, the difference is mainly in the structure of the impellers. The former is in closed structure and the latter is in semi-open structure. The reason why the efficiency of the semi-open type is low is the problem of radial returning flow and axial slipping flow. The BF flotation machine overcomes the problem of radial returning flow and axial slipping flow, which make the impellers get a much larger absorbing strength with a low rotary speed. The energy consumption is reduced and within the flotation cell, double circular, large absorbing amount, and low energy consumption are suitable for the course flotation, so the BF flotation separator is widely used.
The flotation machines’ transformation is divided into 4 steps. The first step is transforming the third flotation system’s flotation machines which locates in the south part of separation workshop, After getting satisfied technology index, we start the second step which is using the BF-1 flotation from the third flotation system replace the JJF flotation machines of the forth flotation system. The third step is transforming the second flotation system’s flotation machines which locate in the north part of separation workshop. The forth step is using the BF-1 flotation from the second flotation system replace the JJF flotation machines of the first flotation system. After adopting BF-T flotation machines, the separating equipments run stably, the high of pulp is easily adjusted, and the index of flotation is proved.
Currently, our domestic flotation machine can basically meet the different requirements of ore selective factories. According to the type of ore, it can deal with non-ferrous metals, precious metals, ferrous metals and non-metallic. As for the size of the ore selective factory, it can be used by factories whose daily processing ability is under ten tons. In terms of granularity, it can separate normal sized ore as well as course ore. Flotation machines can be used in course separation, sweeping separation, fine separation and milling cycle.

Ways to Maintain and Repair the Lower Bearing Grader of Classifiers

The specification of classifier.html">screw classifier is decided according to its size, which is convenient and rapid, but the defect is short service life, which is normally nine to fifteen months. Users could depend on the processing capacity and broken degree of main bearing of the classifier to decide the repairing methods or replace completely.
There are generally two structural forms in the lower bearing grader of classifiers: the first is the rolling bearing and the second is rubber bearing supports. The main cause of damage of rolling bearings is the leak of seal which leads to the damage of rolling bearing, and the main reason for sealing leaks are that the packing wear loose and high-pressure grease isn’t maintained timely. Replace the rolling bearings, and pack the oil asbestos repeatedly to compress it tightly. Fully fill the bearing internal cavity with grease lubrication, and add lubricating grease frequently into the bearing to maintain the outer pressure to avoid pulp invasive, which needs a higher sense of responsibility of the operation and maintenance workers. Normally, the lower supporting base can be used up to a year, but because of the quality of installation and replacement, or the untimely lubrication, its service life could be reduced to less than one month sometimes. Therefore, many users have improved the seal of the base, and they replace the oil asbestos with V-shaped ring of rubber or polyurethane material successfully, so the multilayer stack together instead of seals asbestos packing. Because rubber and polyurethane have good flexibility and abrasion resistance, the sealing performance compared to asbestos packing is significantly improved, and the service life of the rolling bearing is also longer.
In the preparation of the raw material, due to the negative pressure generated by the high speed rotation of the wind wheel and the negative pressure generated by the outlet connected to the rear fan, hot air from the hot air inlet is introduced, and continuously fed by the wind wheel radially. The broken materials form much even materials curtain after the sinking process in the wind separating area, and then they contact with hot wind fully and have heat transfer to be dried. Wet air is discharged from wind port. After wind sub-constituency materials in contact with the hot air in the suspended state, the efficiency of the classifier is higher, and the drying effect is remarkable.

The Research and Development of Intelligent Automated Rotary Kiln

Large-scaled rotary kilns are widely used in metallurgy, ore beneficiation, cement production line and environmental protection. It is hard to achieve the automated control and optimized control of rotary kiln because of their multi-factors, close coupling, non-linear and serious interference of key parameters. It is much meaningful for the improvement of the quality of clinkers and the using rate of rotary equipment, and the reduction of energy consumption to research the intelligent optimized controlling technology and intelligent optimized controlling platform.
The intelligent optimal control software platform of rotary kiln is a kind of application software to control and monitor rotary automation. The technology of foreign control system software is non-transparent. Although their control on basal loop is stable, intelligent control is rarely mentioned. Because of the development of domestic software platform starts later than abroad, their structure of the platform isn’t strong enough and reuse rate of code isn’t high enough. Therefore, the research on intelligent optimal control software platform with modular structure and the function of developing intelligent optimal control strategies is necessary. The detailed works have been summarized as follows: 1. The whole structure and function of the platform are designed. The structure of the platform is established and combined with modules organically. We organize the structure of intelligent optimal control software platform with more clarity and reusability.2. The platform is divided into four modules: plot module for human machine interaction of rotary kiln, database module for the management of control volume and detection volume, communicate module for data transmission with lower computer, strategy module for development of intelligent optimal control. In order to achieve ease of use and scalability, powerful base classes are designed and implemented by the object-oriented language.3. To the strategy module, a method is proposed based on the design of flow chart, generating script dynamically, explaining and implementing by compiler of the system. This method can reduce the volume of developers programming, so they can focus on the development of intelligent control algorithm.
The active lime is the basic raw material for steel and ore industry. it can shorten the calcining time, improve purity and recycling rate of liquid steel, reduce the consumption of quartz and fluorite and improve the service life of kiln bucket, besides, it can also be used in the process of steel perfection. The rotary kiln, as one of the major calcining equipments, is widely used in our country, and it has wide materials shape, size adaptability and good inner mixture.

Some Ways to Improve the Grinding Efficiency of Ball Mills

If the ratio of ore and water is too large, the viscous slurry would slow down the rotation of ball mill, and as a result, the grinding efficiency of grinding media will be decrease. But if the ratio is too small, the thin slurry will lead to the direct impact of the grinding media to increase the wear and tear of the grinding body, also cause increased evaporation in the spray-drying process, which could waste the fuel and decrease the discharging ratio of spray drying tower. Usually for ore containing more plasticity raw materials, the ratio is smaller; the ratio should be larger is more barren raw materials are contained.
The grinding medium and materials within the ball mill have three kinds of moving states because of the different rotating speed of the ball mill: drop motion; throwing motion; centrifugal motion. The normal working states of ball mills are drop motion and throwing motion. According to the observation, the more close to the ball mill cylinder, the more the amount of the grinding medium. Only making full use of the outermost layer of the material can make the maximum efficiency of the ball mill. By the theoretical calculation that, when the outermost grinding media detachment angle of 54.73 °, the outermost layer can obtain the maximum falling height of the material in the most effective pulverization. Found from the actual operation, when the operating speed of the ball mill is adjusted to critical speed of 0.75 to 0.85, the grinding medium could reach higher place.
In the ore separating line, the ball in a ball mill is continuously worn. In order to maintain a stable operation of the ball mill and to maintain a reasonable ratio of the filling rate, balls must be reasonably complemented. Reasonable complement of balls is one of the key issues to improve the efficiency of the grinding process.   Regularly check the ball mill in accordance with its actual situation, accumulate data, revise the ratio, and finally reach a stability ball charge ratio and reasonable purpose of the complement ball. Normal complement ball only refer to a large ball, and users do not make up a small ball, because the ball can be worn by the big ball. In summary, select the best rotation speed of the ball mill, filling rate and high-quality steel ball, and be careful to draw the ore particle size characteristics curve, in order to determine a suitable size of the steel ball, ball ratio, and gradually mastered the production complement ball law is an effective way to improve the ball mill efficiency.

The Cement Rotary Kiln is Moving Forward

  The technological performance of cement rotary kiln is marked by production capacity, heat consumption and rotary ratio. The production capacity means the amount of clinker produced per day, heat consumption means the quantity of heat used by rotary kiln to produce a kilogram of clinker, and the rotary ratio means the ratio of rotary time and calendar time. Because of the difference in production way, usage of waste air and remained heat, and the cooling way of clinker, the types of rotary kiln vary. Cement rotary kiln can be divided as wet type, semi-dry type, and dry type according to the moisture of feeding materials.
  The rotary kiln is rotating around its own axis of the steel cylinder ,containing a firebrick sorts, in which the burning material, Kiln floating on the basis of the supporting wheel, the wheel can rotate with the rotating kiln. The wheel is fixed with the reinforced concrete foundation, Kiln load can be passed to the foundation by the wheel. According to the vibration of the rotary kiln equipment for concrete production, the subject of finite element simulation to large-scale dynamical foundation is put forward in this article. The work is on the dynamical characters of the kiln-base-foundation systems. Because of the complexity of the system, we must consider the deformation coordination of the rotary kiln and the foundation.
  Having a comprehensive understanding of the kiln’s foundation and superstructure, making a detailed analysis of how the endogen force happens of kiln’s foundations, discussing the calculation method of the kiln’s foundation, loading time history analysis on the kiln model with the acceleration curve which obtained at the scene. On the base of the method of the finite element, we developed large-scale soft and made parameterizations of the finite element programming. With the visual basic language, we compiled window-interface, set the parameters about the physical dimensions and material properties of the equipment, the kiln’s foundation and the geology data of the understructure as the input variables. In the future, we can achieve the following purpose: guiding the project design, optimization indicators of the kiln’s foundations, achieve reasonable economic purpose.

Rock crushing plant : http://www.ore-machine.com/stone-line.html
Jaw crusher : http://www.hxjq-crushers.com

Traditional Crushers can hardly Meet the Current Needs

  Traditional jaw crusher is widely used in industries because of its simple structure, reliable operation, easy manufacture, convenient maintenance, low price and high adaptability, but its disadvantages are discontinuous crushing, relatively low efficiency, small crushing ratio, uneven wearing of jaw plate caused by uneven feeding. According to its disadvantages, many countries are trying to improve crushers in the following ways: improve the structure and moving trail, change the type of crushing chamber to increase the crushing ratio and working efficiency, and decrease the wearing and energy consumption; improve the hanging way of mobile jaw plate and the supporting way of bracket to improve the performance of crushers; new wear-resistant jaw plate decreases the wearing consumption; improve the degree of automation, such as automated adjustment, overloading protection, automated lubrication, and so on.
  A jaw crusher is a kind of classical size reduction machine which is widely used in mineral, traffic engineering, building metiarial, and ceram fields. In order to improve the jaw crusher performance, such as lower wear rate, higher efficiency and lower power draw. Some jobs have been carried out on some regular parameters, such as length of coupler, nip, suspension height of basic shaft, stroke of moving jaw, etc.. For these parameters, once they are determined, they will be the designing foundation of the machine and cannot be changed in the operation. Since the parameters of this kind of jaw crushers are non-adjustable, its application and performance is constrained. At present, the overseas goal of the mining equipments is getting the advanced predominance than those countries such as our nation. So they will do their best on the big-scale, system automatization, high efficiency and low energy. The modern manufacture technologies are the foundation to reach such a goal.
  At the same time, some new types of machines are also introduced, such as double chamber jaw crusher(easily adjustable discharging port, high production capacity), single toggle jaw crusher( combined performance of jaw crusher and cone crusher; production capacity is 50% higher than other crushers with the same specification), and screening jaw crusher( combination of screen and crusher decreases the block and over crushing of crushers, improves production capacity, and decreases the energy consumption).

Research to Improve the Performance of Jaw Crusher

From the current situation of the crusher machine, we can see that the weight of crushers in China is higher than that in abroad, and the design of jaw crusher still emphasizes on experience. With the development of computational methods and computer technology, under the premise to meet the needs of strength, stiffness and safety performance, improving the structural design of the movable jaw to reduce the weight of machine is a feasible solution. The large horizontal displacement of mobile jaw is available for crushing materials. Moving along the direction of movement of the mobile jaw promotes discharging effect, so we can guarantee the efficiency of the production of the crusher to a certain extent. The vertical displacement of mobile jaw is also large in the simulation, so the lining board will be worn quickly, and its service life will be decreased. As the development of wear-resistant materials and the improvement of liner’s wear-resistant ability, jaw crusher is gradually developing to a larger size.
  A jaw crusher is a kind of classical size reduction machine which is widely used in mineral, traffic engineering, building material, and chinaware. In order to improve the jaw crusher performance, such as lower wear rate, higher efficiency and lower power draw. Some jobs have been carried out on some regular parameters, such as length of coupler, nip, suspension height of basic shaft, stroke of moving jaw, etc. For these parameters, once they are determined, they will be the designing foundation of the machine and cannot be changed in the operation. Since the parameters of this kind of jaw crushers are non-adjustable, its application and performance is constrained.
  At present, the overseas goal of the mining equipments is getting the advanced predominance than those countries such as our nation. So they will do their best on the big-scale, automatization of system, high efficiency and low energy. The modern manufacture technologies are the foundation to reach such a goal. In general, the basic problem of jaw crusher designing and researching is how to set the springboard on changing the traditional parameters into operational ones using PC technology under the concept of innovation. In order to reach this purpose, the detailed kinematic and dynamic designing and applications of the PC technology are required.
 

When Jaw Crusher Stops Working

No matter in sand production line or stone production line, our aim is to ensure the impact crusher and jaw crusher machine are capable of normal continuous operation. In order to extend the life of the crusher, we must provide periodic maintenance and conservation to crusher. So, here I’d like to remind manufacturers of idling the machines before consignment to reduce the problems happened in the following time. New users must fully check crushers after each shift to see if any accessories have been loose or worn.

If you find the production capacity cannot reach the standard set by manufacturers. The reason could be the degree of hardness or toughness is over the limit set on the instruction; the wire of motor is connected reversely, so that the main body runs reversely ( mobile jaw rotates deasil.), or the triangle connection of motor is connected in the shape of star; the discharging port is smaller than the regulation; jaw plate moves, and tooth crest is connected with tooth crest; the voltage is too low in the working site; the space between mobile jaw and bearing is too large because of wearing, so that the outer circle rotates relatively.

The way to remedy those problems are replace or increase crushers; change the connected way of motor wiring; adjust the size of discharging port according to the instructions and increase crusher for fine crushing; check the length between teeth plate, adjusting the relative position between the fixed jaw plate and mobile jaw plate to make sure the tooth crest is connected with the tooth root, and then fix clamping to prevent displacement; increase the voltage to meet the heavy-loaded requirements of the main body; the replace the bearings or mobile jaw.

If there is any beating or percussion during the operation of jaw plate, the reasons could be fastening bolts are loose or falling; the discharge opening is too small, so that the bottom of the jaws impacts each other. To solve this problem, we must fasten or set new screws; adjust the discharging port to guarantee suitable space between two jaw plates.

Some Important Parts of Hammer Crusher

Rotor is hammer crusher’s main working parts, and the rotor is formed by the spindle and hammer holder. The hammer pin on the hammer holder divides the hammerhead into three rows hanging between the hammer frames. In order to prevent the axial and the hammerhead traversing, the two ends of the frame are fixed with the compaction hammer plate and the locking nut. The rotor is supported by the two rolling bearings fixed to the lower rack with the abutment of the bolt. Except the bolt outside, there are two locating pin fixed to the center of the bearing distance. Further, in order to store a certain kinetic energy in operation, the flywheel is mounted at one end of the spindle.

The hammerhead is the main working parts of a hammer crusher. The weight, shape and material of a hammerhead have a great influence on the production capacity of the crusher. Hammerhead’s kinetic energy is proportional to the size and weight of the hammerhead. That is to say, the heavier the hammerhead is, the greater the kinetic energy of the hammerhead and the crushing efficiency are. However, the heavier the weight of the hammerhead, the greater the centrifugal force to spin up, which must have an impact on other parts of the hammer crusher rotor, so the weight of the hammer should be moderate. The heavy Hammerhead could weigh tens of kilograms, but small hammerhead could only weigh a few kilograms, and usually not more than 80 kg. The reasonable choice of hammerhead’s material is very important, because ordinary carbon steel produced hammerhead for crushing limestone will wear out within a few days, but the high manganese steel casting hammerhead after the surface hardening heat treatment can be used for a long time. The current design of hammerhead has developed into modular structure design from the traditional overall design. In addition, the development of new materials, especially high hardness, wear-resistant material was successfully developed, which provides the guarantee for improvement of the design and performance of the hammerhead.

The role of the counter plate is to bear the impact of broken materials crushed by the hammer, and rebound them to crushing area to have next-time impact crushing. The requirement of design is the place where materials are rebounded back should be the place where the hammer passes, so that the hammer can crush the materials again. After several experiments and comparison, the rib is the best choice. The angular of rib can be very hard and wear-resistant after being cast and heated.

The Compressive Process of Jaw Crusher

Jaw crushers have many advantages, including big reduction ratio, equal product granularity, simple structure, reliable working condition, convenient repair and economical operation. They are widely used in the works of mine, smelting, building materials, road, railway, irrigation, chemical industry, etc. The compression strength of the materials to be crushed is less than 320MPA. Now, let’s have a research and analysis of the compressive process of jaw crusher.

In the compressive process, materials may rest or sport. In the process of movement, the type and direction of friction endured by materials given by fixed jaw bucket have a decisive relation with the vertical speed of contact point between materials and fixed jaw bucket. However, the type and direction of friction endured by materials given by mobile jaw bucket have a decisive relation with the tangential speed of contact point between materials and mobile jaw bucket. During the research on the compressive process, more attentions are paid on the jaw board face a point forward horizontal displacement increase process, and think that when jaw have positive horizontal displacement, the material will endure positive pressure applied by jaw extrusion. Obviously, this treatment is simplified the extrusion process excessively as moving jaw translation of a definition. In fact, compound jaw crusher of the moving jaw is a complex plane movement, and when it moves horizontally, it will also move vertically.

In order to effectively analyze the compression and relative movement between materials and jaw bucket within compressive cylinder, materials and jaw bucket will all use rigid model. In order to interference of rigid model, we set for the fixed jaw plate a virtual horizontal direction of freedom of movement. That is to say, the deformation of the material will be shown by the horizontal movement of the fixed jaw plate. The extrusion amount of deformation of the material in the extrusion process is equal to the set amount of displacement of the jaws. Obviously, for the material of the specific crusher and materials, the amount of displacement of the scale plate is a variation amount over time, which is always larger than zero, and unidirectional increase, not decrease during the extrusion process. The increase in the horizontal displacement of the fixed jaw plate means that the material will have a horizontal velocity and acceleration, but the actual material in the fixed jaw plate doesn’t have any horizontal displacement. Knowing more about the compressive process of jaw crusher can help us to find problems if there is something wrong with the crushing machine.