Affecting Factors to Lifespan of Vertical Roller Mill

Building material market is booming with urbanization development, and that also leads to the development ofvertical roller mill. Vertical roller mill, as a kind of high-efficiency energy-saving environment protection equipment, is more and more popular with more customers and has gradually replaced traditional ball mill. 

Study proves that high quality mill and correct operation is key to prolong the service lifespan of vertical roller mill, also to increase its grinding efficiency. So, how to prolong its service lifespan? 

Firstly, material hardness and content is important.

Different materials with different hardness and contents will cause different abrasions of grinding roller, grinding table, and liners, therefore, appropriate selection of material can effectively increase the service lifespan of vertical roller mill. 

Second, material feeding status is also important. 

Feeding evenly is an important factor to guarantee normal operation of vertical roller mill, if there is no configuration of feeding equipment for production line, there will be plugging material. Uneven feeding will press much pressure on grinding roller, and cause abrasion directly, thus reducing service lifespan of mill. 

Finally, it is technicians’ correct operation and maintenance. 

Generally speaking, if the worker do not know about the machine, it is difficult to operate and maintain it, and this will cause the low production efficiency. Therefore, there must be professional and technical personnel to operate it, to perform correct sequence. When starting it, he should first start the blower, then start the main machine. When stopping it, he should first stop the main machine, then stop the blower. A series of problem including electrical short circuit, will be caused if the operator does not obey the correct sequence.

Vertical mill equipment is efficient or not is fundamental to production benefit, therefore, vertical roller mill is pivotal in an engineering project. To choose a good vertical roller mill means to choose a good start. 

Xinxiang Great Wall Machinery has been dedicated to manufacturing vertical mill for more than 50 years, including Research & Development, manufacturing, sales and service, and pays much attention to improve mill quality and meet customers’ requirements. The grinding roller, grinding table and liners, with long-term contact with feeding material, are main wearing parts. The vertical roller mill manufacturers pays special attention to improve wear resistance to improve lifespan of vertical will, the Great Wall Machinery has great superiority in this respect with its large cast steel base, large machining workshop, electric control workshop, thus ensures qualified large parts of mill. This can not only ensure the production quality, production process but also solve vertical mill repair problem. 

Cement Rotary Kiln Air Volume Control in Cement Production Line

In cement production line, vertical mill and Cement Rotary Kilns are the core equipments in cement production lines,I have said vertical mill in detail. Today, Let us find out more about the Cement Rotary Kiln, cement rotary kiln is at the time of work, the air volume control is close important, it directly affects the production of the finished product, the following specific as we explain how wind Cement Rotary Kiln control:

1.In order to form a circular flame stabilizing the flame. Cement Rotary Kilns primary air volume is too low, not only can not be carried into a secondary air within the wind, improving combustion flame speed, but also no extra momentum to form a circular flame, the flame is not conducive to stability, indirect combustion system is particularly important.

2.The burner production requirements can not be too high. A Cement Rotary Kiln burner air volume is too low, the corresponding pressure must be high, otherwise it will create momentum insufficient mixing of combustion and secondary air is difficult to effectively, while high pressure is bound to make the burner and fan made higher requirements.

3.The material must be burned completely. An amount of wind Cement Rotary Kiln is a case for the premise, that is shock-type flame not be occured, no carbon monoxide emissions.When the primary air volume is too low,it is not conducive to the air mixed with fuel,make the carbon incomplete combustion, thus reduces the thermal efficiency.

In summary, Air volume and wind speed of Cement Rotary Kiln are indeed important parameters. The role of secondary air is the key to accelerate the combustion flame speed and the formation of recirculation. Also,under the condition of air volume not enough, how to use the excellent burners generate enough wind speed, and in the cooler, the air force with the kiln hood Department, to achieve a reasonable control of the flame is the key.

Together with China National Aero-Technology Import and Export Beijing company to build a cement line project in Kenya

　

　　Graph: Export Kenya φ3.8 × 13m two double sliding shoe mill warehouse

      In recent years,the Great Wall machinery with China aviation technology import and export company in Beijing cooperation, for Kenya provide 1 Φ 3.8 x 13 m two warehouse double slipper grinding mill production services,the two warehouse double slipper ball mill is the first fundamental solution to the "due to the discharge end bearing shell temperature can not be a continuous operation" of the problem.

　　Since the completion of the project, the customer in Kenya as the center, and gradually East Africa seven market to provide services, promote the development of Africa's cement market and prosperity.The success of the cement project construction, making the customer information greatly increased, and take the initiative to hope there will be more and the Great Wall machinery have a better cooperation.

The New Type Vertical Mill Advanced Technology Improves the Concretes Performance

These years, a new highly developing concrete technology has been applied in many practical projects. It is the high performance concrete. The durability is the main index for its design. Regard to the different requirements, it guarantees the durability、construct-ability、applicability、strength、volume stability and economy etc. It has the low water-binder ratio, use the good quality material, except cement、water and aggregate, also should add enough quantity mineral admixture and high admixture.

　　By adding the high quality mineral admixture, improving its compaction、reducing the concrete gap capillary、improving the interface and micro-structure between aggregates and cement colloid、improving the concrete quality、preventing large quantity harmful materials coming into the concrete and reduce the concrete erosion.

　　According to the scientific experiments, with the suitable mineral admixture adding, the cost little increase. Especially when C30 concrete add 20% coal ash and 20% slag powder, the cost is nearly same with the original concrete. The concrete factories can use the lower cost to earn more benefits.Combining with our national situation, high performance concrete mineral admixture mainly add the coal ash and mineral powder.Coal ash should use the stable quality products.The strength of concrete below C50 should use the coal ash national standard level I or level II, but the ignition loss≤5.0%, fineness ≤20%. Coal ash should use the water quenching grinding products, the specific surface area is 350-500m²/kg, 28 days activity index≥95%,ignition loss≤3.0%,moisture content≤1.0% etc.

　　As the famous grinding system supplier in China, Great Wall Machinery can be the support of concrete industry. In order to improve the quality of concrete, and realize the energy saving, we have produced the new type vertical mill. This mill has good grinding power, low power consumption and provide good quality products. The coal ash’s specific surface area is 420—450㎡/kg, 7days activity index can reach 100%. Most important, this mill not only can grinding the slag, but also can grinding the coal ash. It save the customer’s equipment investment and maintenance cost. Now, our new type vertical mill has already used in the 350,000t/a slag powder /coal ash production project of Harbin three new energy-saving building materials co.,Ltd.

Better Choice for Energy-saving and Environment-protection - Great Wall Vertical Roller Mill

Recently, Revised Draft of Air Pollution Prevention and Control Law accepted by State Council executive meeting has drawn a heated discussion.

　　The Revised Draft stresses the source management and public participation. It also increases special provisions of collaborative governance and regional joint prevention and control of pollutants on key areas, industry, motor vehicles, dust, etc. It makes clear the punishment measures for undocumented, standard- exceeding discharge and fraud monitoring data behavior.

　　Air pollution caused by coal burning, industry, dust, etc is more and more severe, the Revised Draft requires key discharge units should install emission automatic monitoring equipment in accordance with the national standard, and other enterprises monitor its emissions of industrial waste gas discharge, also requires the implementation of equal or reduction replacement of coal consumption.

　　Serious haze weather in major cities makes people more and more worried in recent years, and requirements of air pollution management are more and more urgent. The air pollution problem is not only related to government's policies and laws, it is but also to improve the living environment.

　　Cement industry as an important factory in China, supplies the cement products for various fields, also provides an important research about the dust pollution and energy-saving problem.

　　Great Wall Machinery as professional cement equipment manufacturer of cement equipment including vertical roller mill, ball mill, rotary kiln, etc, has done many R & D tests on energy saving, environmental protection, abrasion resistance and automation. Great Wall Vertical Roller Mill is best in environmental protection, energy-saving, the highest degree of automation, enjoys character of large-scale production requirements of cement equipment. You are warmly welcome to visit our company!

2.6x13 m cement mill to increase production pathway

In the cement production proces,cement mill is one of the key equipment of cement,cement mill consumption accounts for about 60% -70% of overall power consumption of cement.Raw mill quality decisions and influence the technical parameters of cement rotary kiln,but if cement mill configuration is more reasonable,they can make up for some defects of cement clinker.Therefore,improve the output of cement mill,to realize high quality, high yield, low consumption of cement enterprises has very important practical significance.So, 2.6x13 m cement mill how to achieve high-yield it?The way to achieve high yield and quality and what it?

　　1. Reduce the grinding particle size

　　Cement companies use cement mill + roller mill grinding can be dropped into the mill size 2mm below, production increased by more than 50%.

　　2. Optimize the cement grinding process

　　The open system to the closed system, the addition of efficient rotor separator and bag filter,thus increasing the cement surface area,increasing the strength of the cement with good results.

　　3. Control the grinding material moisture and temperature

　　To integrate into the grinding material moisture control at 1.5%, is the basic premise of high quality and high yield of cement mill.Therefore,cement enterprise need water to mixing materials and material production process strictly control the water drying, grinding into the material temperature control process requirement within the scope of guarantee good operation of the cement mill.

　　4. Control the grinding material easy to grind

　　If you want to improve cement grinding production, you need to optimize the structure of cement raw materials, improve the material was grinding grindability.

　　5. Ensure the ventilation flow in the mill

　　In daily production, cement enterprises should fully realize the importance of the mill ventilation , at the same time, sealed to prevent air leakage to do the work. In addition, you can use powerful ventilation and bag filters and other measures to ensure the smooth ventilation inside the mill.

　　6. Adjust the grinding body in grading

　　According to the actual production needs in equipment configuration allows, appropriate to add the ball, loading capacity,to improve the mill output is very helpful.In addition, because the cement grinding mill work environment is harsh, often in direct contact with all kinds of cement raw materials,the wear is quite serious, therefore, should pay attention to the breakage of the grinding bodies.

　　7. Control the fineness of finished product

　　As we all know, the control index of cement fineness has a great influence on the cement performance. Cement enterprises can through the sieve analysis method to control the cement fineness, 0.08 mm sieve allowance to control in 1.8% 2.8% more appropriate.

　　Great Wall machinery since its inception, has been committed to the vertical grinding machine, tube mill, rotary kiln, the cement equipment research and development and production,is now with the slag/steel slag vertical grinding machine (mainly the EPC project), cement mill developed into China's large grinding system integration suppliers.If you have similar technical problems encountered in the production, you can seek advice to the Great Wall machinery!

Two Advantages of Great Wall Vertical Mill

After almost a decade cooperation with veteran experts on vertical mill manufacturing and scientific research institutes both in home and abroad, the GRM series vertical mills dedicated to be developed and produced by Xinxiang Great Wall Machinery Co., Ltd, have the characteristics of reliable performance, compact structure, convenient maintenance and outstanding energy saving etc. Here are two more important advantages of Great Wall vertical mill.

　　Wear protection

　　The grinding plant, which is carefully maintained by the owner, provided high availability and trouble-free operation. None of the wear protection plates in the mill housing and in the grit cone of the separator have yet needed replacing. Only the ceramic castable in the upper housing section of the separator was replaced by wear-resistant steel plates soon after the commissioning. Once a year, after approx. 3500 operating hours and production of 300,000t of ground blast furnace slag, the surfaces of the grinding elements are refurbished by build-up welding during a planned maintenance stoppage. The specific wear of grinding track and roller tyres, taken together, is 7.3g/t.

　　For long service life of the grinding tools not only the appropriate wear lining is important. The iron extraction system in the external material circuit is an extremely important feature of the Great Wall vertical roller mill for slag grinding.

　　Iron extraction system

　　It is a well-known fact that iron particles in the granulated blast furnace slag are the main cause of wear in the mill. Therefore it is extremely important to remove the maximum possible amount of this iron. The external material circuit is very well suited for this purpose, because it handles a large quantity of material, some of which is already partly ground.

　　The material passing through the nozzle ring falls onto a discharge ring rotating with the grinding table. This material then passes via a discharge chute into the bucket elevator.

　　The material discharged by the bucket elevator is fed to a vibrating trough, to ensure a uniform feed rate to a magnetic drum separator. The aeration of this magnetic drum separator is so designed that practically pure iron with no granulated slag is removed from the stream of material. After the magnetic drum, the recirculated material finally returns to the grinding table. The incoming granulated blast furnace slag has an iron content of 0.28%, corresponding to an iron quantity of 210kg/h.

　　The recirculating material in the bucket elevator has an iron content of 0.7%. The magnetic drum separator removes around 170kg of iron per hour in permanent operation. The iron contents found in the roller mill and in the finish product impressively illustrate the efficiency of the external material circuit for concentrating the iron and facilitating its removal. Such efficient extraction of iron in the grinding process has a very positive effect on wear in the mill.

　　In the world, many granulated blast furnace slag grinding plants are already in operation, but the number of granulated blast furnace slag grinding plants is still low. Customers from all over the world who are now interested in slag grinding are invited to send their inquiries to the Great Wall Machinery. Any of your inquiries will get prompt attention.