Modification of combined cement Mill system of Ball Mill and Roller Press

Date: 2019-07-01 Views:

Under the condition that the productivity of cement plant is low and the production time is long, cement production enterprises need to improve the equipment so that the production volume and production efficiency can be effectively improved. In this paper, the transformation of the combined cement grinding system of 4.8m*9.5m ball mill and roller press will be analyzed and studied.

Introduction of combined cement grinding system of 01 4.8m*9.5m ball mill and roll press


With the development of modern science and technology and the continuous innovation of technology, the process of industrialization in cement industry has been accelerated, the production technology has also been greatly improved, and the process control technology has also been upgraded. The process and equipment of cement grinding powder are mainly ball mill, and the development is mainly composed of high-efficiency vertical mill and roller press. The process combination of these equipment makes the cement industry develop towards the direction of large-scale grinding equipment, technological control technology and intelligent production machine and equipment.

In order to meet the needs of large scale and modernization of cement production, the combined cement grinding system of ball mill and roller press has been reformed. In all kinds of powder flow of roller press, the combined grinding system composed of V-type static separator and roller press has obvious advantages, which has the advantages of high output and low consumption.

Our company's cement grinding system is composed of 1600 mm * 1400 mm roller press and 4.8m*9.5m ball mill, which is a closed circuit system with cyclone separator. The system is a short rough grinding and cyclone powder separator system introduced from abroad, and it is considered that the production effect of this system is good, so the configuration type of the design institute is put forward after the production. The ball mill process scheme of cement ball mill and roller press is a mature process system at present, which can meet the basic needs of grinding process to the greatest extent.

After the combined cement grinding system of 4.8m 9.5m ball mill and roller press is put into production, the output of the system is low, and the energy consumption of cement unit products is very high, and the comprehensive power consumption per ton of cement is more than 38 kilowatt hours. The author organizes the technical analysis of the relevant professional engineers, and finds that the reason for the large power consumption is that the detail design of the mill itself is not perfect, the structure design of the mill liner and the partition board is unreasonable, which leads to the flow rate of the material in the mill is too fast and the efficiency of the mill is reduced. Second, the efficiency of whirlwind spinning machine is too low, generally between 30% and 40%. After a period of production experience summary In this paper, the details of the ball mill are improved, and through the replacement of the liner form, the original groove ladder liner is replaced with the same graded liner as the two warehouses, the partition plate is cancelled, the double warehouse mill is changed to the single warehouse grinding mode, and all the unreasonable ways are reformed and put into production again, the output of the system is increased and the power consumption is also reduced to a great extent.

The output of cement system has been increased from 150t / h (P ·042.5, 370m / kg) to 170t / h (P ·042.5, 370m / kg). The comprehensive power consumption of cement also decreased from 38 kilowatt-hours / ton to 35 kilowatt-hours / ton. However, because of the low efficiency of the powder separator, this problem has not been effectively solved, the ability of cement grinding has been unable to reach the design capacity, the unit cement power consumption is high, and the gap with the national advance value is very large. In order to reduce the cost of production, the efficiency of the enterprise has been improved High, we further study and reform, replace the original cyclone powder separator with high efficiency powder separator, improve and optimize the unreasonable place of the previous system.

A brief introduction to the system of technological Reform

(I) introduction to the system before the technical reform


The previous system is composed of V type powder separator, roller press, cyclone dust collector, ball mill and cyclone powder separator. The ball mill system is a closed circuit system. The cyclone dust collection system of roller press system, the ventilation of ball mill itself and the air release of cyclone powder separator are all independent dust collection systems.

(II) basic ideas for the application of the system


By using the semi-final grinding technology, on the premise of fully ensuring the quality of cement, the fine powder in the pre-grinding system which meets the production conditions is screened out by the separator and transported directly to the cement depot through the oblique slot. According to the experience of cement production, the ratio of the installed power of the roller press to the installed power of the mill is more than 0.6 by using the semi-final grinding technology, and the ratio of the installed power of the roller press to the installed power of the mill is very small, only 0.357. Therefore, the application of semi-final grinding process is very difficult.

(III) systematic introduction after technological reform


The main contents of the technical reform include the removal of V type powder separator, high efficiency cyclone dust collector, cyclone dust collector and dust collector composed of circulating fan, and the installation of high hanging cyclone dust collector, so that the air volume can be used as the main air source of high efficiency horizontal vortex separator. The cyclone powder separator should be completely replaced. By using the high efficiency powder separator, the circulating fan used in the previous cyclone powder separator and the dust collecting fan system used in the cyclone powder separator should be reset so that it can be used in conjunction with the dust collector and fan in accordance with the high efficiency powder separator. Disassembly of air conveying chute and fan for partial transportation of cement finished products Except for processing. The investment in the technical reform project of the whole system is 5.5 million yuan, of which the excess budget is the construction project.

(IV) cycle and effect of technological reform


From the design to the end of the technical reform, it took about three months to install. The technical reform was carried out in the off-season of cement sales, just using our company's cement mill overhaul period. After the technological reform began, a series of problems appeared after it was put into operation. For example, the ash from the separate ventilated dust collector of the mill is too rough to form a finished cement product. After that, the ash collected by the dust collector is directly connected to the hoist of the high efficiency powder separator; after transporting the material into the air transportation oblique slot of the high efficiency powder separator, there is no setting of the material distribution, resulting in the material distribution of the high efficiency powder separator is not uniform enough, so that the high efficiency powder separator is not uniform enough. The efficiency of the powder separator is greatly reduced. Later, the material separation device was installed above the inclined slot of air transportation, and the phenomenon of uneven material distribution was adjusted technically to solve this kind of phenomenon.

According to the sampling and analysis of materials in the system, the fine powder selected by the powder separator in the early stage needs to be imported directly into the cement storehouse, but the operation efficiency of the modified machine is improved, the fineness of cement is not enough, and the fineness of cement becomes rough, which has a great influence on the comprehensive production of the system. It is decided that this part of the material will not enter the grinding hoist, and the grinding will be carried out again, so that the number of rotations of the separator will be reduced, and the quality of the finished cement will be greatly improved. After the technical rectification and reform, the output of the system has been greatly improved. From the previous 170t / h (P ·042.5, specific surface area 370m / kg) Under this condition, it has been increased to 180t / h (P ·042.5, specific surface area 370m / kg),) and the comprehensive power consumption of cement has decreased from 35kWh / t to 33kWh / t. If the annual production of each system is calculated according to 1 million tons of cement and the electricity per kilowatt hour is calculated at 0.5 yuan, the cement company can save about 4 million yuan a year, and in about a year and a half, it will be able to recover the investment cost.

03 conclusions after technological reform


From the results of the technical reform, we can get that the efficiency of the high efficiency powder separator is higher than that of the cyclone powder separator, and the output of the system has been greatly improved. After the reform, the output of the system has been increased by nearly 16%, and the power consumption per ton of cement system has been reduced by 5 kilowatt-hours. Although there is no long-stride development in the improvement of system output, there is still a certain distance between the comprehensive power consumption of cement and the national advanced index, but there is still obvious progress. The reason for the gap with advanced indicators is that the effectiveness of the system has not yet been fully brought into play.

After the technicians gradually familiar with and master the system, with a certain amount of experience accumulation, the efficiency of the system can be improved again, and the output can also be further improved. After the effectiveness of the system is brought into full play, the output of the system is expected to reach about 190t / h ~ 210t / h (P ·042.5, specific surface area 370m / kg),). At this stage, the comprehensive power consumption of cement can also reach the advanced target of less than 32 kilowatt-hours / ton. Based on the current output, the input cost can be recovered in one and a half years, and the investment recovery period will be after a significant increase in the output of the system at a later stage. The limit may also be shortened accordingly.

Conclusion


The technological reform not only improves the efficiency of the enterprise, but also has great savings for energy. Cement ball mill roller press supporting process can maximize the characteristics of grinding equipment. Reasonable grinding process and high-efficiency and reliable mechanical equipment are the fundamental guarantee for enterprise benefits. Therefore, in the application of the system, we should give full play to the greatest advantage of ball mill equipment, make the grinding system produce higher, the performance is more superior.

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