IntroductionAt present, cement enterprises mainly rely on the loading machine and manual stacking operation, although the domestic cement industry has also appeared automatic loading and stacking device, but due to a series of problems such as low production efficiency, still cannot meet the delivery demand. When loading cement bags, they will collide, emit dust and…
IntroductionAt present, DCS control system is widely used in cement industry, the system runs safely and reliably, and its central processing unit rarely fails. However, due to unreasonable design or improper use and maintenance, component quality problems or software failures, the power module, storage module, input and output module and peripheral lines, often make the…
01 Fault Analysis The model of coal mill induced draft fan of a company is W4-73-15NO19F, the air volume is 100000m³/h, the wind pressure is 2200Pa, the rated current is 28A, the design speed is 960r/min, the motor power is 250kW, and the actual operating current is 19 ~ 20A. The fan is generally stable…
01 Introduction A 4500t/d clinker cement production line of a company is equipped with a 9MW waste heat power station. The air ejector in the vacuum system of the steam turbine generator set is a water ejector, which mainly consists of 37kW water pump, 10.5kg/h air ejector and 12m³ water injection tank. The role of…
IntroductionA company’s 5000t/d cement clinker production line was completed and put into operation in 2008. In order to achieve the goal of ecological and environmental protection control, the company built a SNCR denitration system in 2012, and used ammonia water with a concentration of 20% to remove NOx formed in the cement kiln. SN-CR denitration…
Introduction A company’s 2500t/d new dry clinker production line was put into operation in 2004, and the equipment has been running steadily. However, in July 2014, the reducer of the raw mill separator suffered mechanical damage. After the replacement of the new reducer, the motor of the separator was burnt out for several times. After…
01 Existing problems The cement combined grinding system of a company is a “one drag two” coil flow process, the roller press is HFCG160×140, the mill is 3.2m×13m, ①3.0m×11m three mill each one, the main production of P•O42.5, P•S•A32.5 cement, the existing problems are: (1) Over grinding phenomenon is serious. In order to ground the…
01 problems Line 2 of a company’s raw material mill is FLSmidthATOX50 roller mill, which was put into use in July 2007. There are three rollers, each roller is equipped with a pull rod head, as shown in Figure 1. The A end is connected with the piston rod of the hydraulic cylinder through the…
01 Introduction The 2,000,000 t cement production line system of a company consists of two sets of ф4.2m×13m mills, and the supporting main reducers are JS150 products developed by a well-known gearbox company in China in the 1980s. Its main technical parameters are: input power 3550kW；; The input speed is 744r/min, the speed ratio is…
01 Process Status Quo In response to the national requirement of eliminating backward production capacity, a company reconstructed a set of combined grinding system consisting of CLM150-100 roller press and 3.8m×13m cement mill, with an annual output of 1.5 million tons of cement, which was put into operation in September 2014. The power of the…
Existing problems The raw mill model of a company is ATOX50. The grinding condition of this vertical mill is stable since it was put into production in March 2008. By the summer of 2015, in order to meet more stringent environmental emission requirements, electric dust collector at the end of the kiln has been replaced…
Introduction A 5000t/d new dry cement clinker production line of a company uses the third generation drive grate cooler, which is divided into three stages to drive grate bed by hydraulic pressure. In the past 7 years since the grate cooler was put into operation, there have been several hydraulic failures. Although each failure was…
01 Existing problems The 5000t/d clinker production line of a company adopts ZGM-113N vertical coal mill, which was put into production in March 2008. After May 2017, the vibration of the mill was too large, the grinding pressure could not be increased (controlled at 7.0 ~ 8.0MPa), and the fineness was too coarse (up to…
01 Existing problems The main oil supply pipeline of the hydraulic system of the grate cooler of a company is a 50mm seamless steel pipe. Most of the hydraulic conveying pipelines are laid in the grate cooler air chamber. The conveying pipe in the grate cooler air chamber is connected with the hydraulic cylinder through…
01 Existing problems A company 5000t/d clinker production line, put into production in March 2008, the production is relatively stable. Since production, we have used NC-15 type three-channel burner, four-channel burner and otong burner, and the best comprehensive use effect is NC-15 type three-channel burner. The burner has the advantages of simple structure, easy adjustment,…
Coal preparation is more used at present, the cement industry vertical slow pulverized coal, raw coal into the grinding feed and measurement plays an important role in the process of pulverized coal preparation, if the equipment is wrong or failure rate is too high, easily happened in the production run coal or broken coal, which can lead to stop number increase in the mill, which severely restricts the system production and operation stability.
01 Existing problems Two clinker production lines of a company (line #1 designed clinker production capacity 700t/d, line #2 designed clinker production capacity 2500t/d) are equipped with a 7.5MW pure low-temperature waste heat power generation project. The single-pressure system is adopted. The steam turbine is low-parameter pure condensate steam turbine, with rated power of 7500kW,…
Introduction Vertical roller mill is widely used in cement raw material, fuel and cement grinding system, and is equipped with feeding and discharging system. However, the feeding and discharging system often has an unsatisfactory effect. For this reason, we analyze and deal with the common problems of the system and solve the problems. 01 Process…
Introduction A company has two 5000t/d clinker production lines, rotary kiln with a diameter of 4.8m×74m, three air duct diameter with a diameter of 3200mm, the production operation has been relatively normal. The castables are often washed away, leading to the damage of the valve plate. Generally, the castables need to be repaired once a…
01 Cause Analysis and Judgment Treatment During the operation of the vertical mill, the motor drives the grinding disc to rotate through the main reducer, which drives the rotation of the grinding disc to rotate the three grinding rollers (120° uniform distribution), and the raw coal falls into the center of the grinding disc through…
01 Introduction Since March 2015, with the increasingly fierce competition in the cement market, in order to control and reduce costs and meet the purpose of tax rebate for comprehensive utilization of resources, a company began to produce clinker on a large scale by using various industrial by-products such as sandstone powder, coal gangue, converter…
IntroductionSince the production of clinker in a company began in July, the burning loss increased suddenly, which had a serious impact on the clinker strength and water requirement. In order to solve this problem as soon as possible, improve the quality of clinker quickly, and ensure the clinker leaves the factory smoothly, the company specially…
Project overview The production line of 2500t/d kiln #1 of a company was started in March 2007 and put into production in May 2008. The company’s geographical location is about 2300m above sea level, which is a high altitude condition. The selection of the firing system is particularly increased in terms of system specifications. The…
Introduction Rotary kiln is the core thermal equipment of cement, metallurgy, building materials, chemical industry and so on. Its normal operation determines the quality, output and cost of products. Due to the high temperature of 1500℃ in the rotary kiln and the large temperature change gradient, there are high circumferential stress and thermal stress in…
Introduction A company’s micro powder production line uses the main motor of 10kV and 4500kW vertical mill. After winter maintenance, it is found that the temperature of the bearing bush after the main motor increases significantly. When the ambient temperature is 8 ~ 10℃, the temperature of the bearing bush is measured to be 70℃…
Existing problems The raw mill model of a company is ATOX50. The grinding condition of this vertical mill is stable since it was put into production in March 2008. By the summer of 2015, in order to meet more stringent environmental emission requirements, electric dust collector at the end of the kiln has been replaced…
01 Existing problems A company carried out technical transformation on two original 2000t/d clinker production lines in 2009, and planned to complete the technical transformation project and put it into production in June 2011. After technical reform, the production capacity of original clinker production line reached 2500t/d, and the highest reached 3100t/d. During technical renovation,…
Introduction Ceramic ball as cement grinding body is not a new thing, the white cement industry early use of cast stone ball that is low density grinding body, and later used a kind of artificial silica ball in the white cement pipe mill application can be said to be the ancestor of ceramic ball in…
A company’s 2500t/d new dry clinker production line was put into operation in 2004, and the equipment operation has been relatively stable. However, in July 2014, the reducer of the raw meal mill and separator was mechanically damaged. After replacing the new reducer, the motor of the separator was burnt out several times in a row. Only after the motor of the powder separator is re-selected can the safe use effect be achieved.
IntroductionThe 2 million tons cement production line system of a company is composed of two sets with a diameter of 4.2m×13m grinding units. The supporting main reducer is JS150 type product developed in 1980s by a well-known gearbox company in China. The main technical parameters are as follows: the input power is 3550KW; Input speed…
NOx produced in cement kiln is mainly thermal NOx and fuel NOx. Thermal NOx is nitrogen in combustion air, which is produced when it is oxidized at high temperature above 1500℃. Nitride contained in fuel NOx is oxidized as fuel and produced during combustion. Both NOx are related to combustion process. The temperature of rotary kiln is above 1500℃, and that of decomposing furnace is below 1000℃. Generally, visible NOx mainly comes from kiln, combining the formation characteristics and main features of NOx. The main method of pre-combustion control is to control the nitrogen content in fuel, but this technology has not been well developed. Combustion process control methods mainly include staged combustion and low oxygen combustion. The main methods of post-combustion control are SCR and SNCR. Generally speaking, both pre-combustion control and post-combustion control require extra equipment, large investment and increased operating cost. The control method of combustion process is from the point of view of optimizing combustion, which only needs to transform the existing equipment without increasing the daily operation cost.
01 Introduction The φ 3.8× (7.75+3.5) m single warehouse air sweep coal mill is used for the preparation of pulverized coal in a 4500t/d clinker production line of a company. The designed production capacity of the mill is 42t/h(80μm sieve, 2% of sieve residue), and the main motor is YKK 710-8 with a power of…
01 Basic fault informationIn November 2009, a company put into operation a clinker production line with a daily output of 5000t/d, which was designed by Tianjin Cement Industry Design and Research Institute and supported by the main engine. TCFC5500 grate cooler adopts technology imported from Danish company to manufacture four connecting rod support structure, as…
Treatment of abnormal thermal bending accident of rotary kiln in operation Introduction Rotary kiln is the core thermal equipment of cement, metallurgy, building materials, chemical industry and so on. Its normal operation determines the quality, output and cost of products. Due to the high temperature of 1500℃ in the rotary kiln and the large temperature…
Kiln tyre is the most important supporting part of rotary kiln. It not only bears all the weight of the kiln shell, but also plays a reinforcing role on the thin-walled cylinder. Therefore, in the actual processing process, the quality requirements are strict. It is a serious accident of rotary kiln equipment that the tyre…
