During the operation of the roller press, the control modes of "constant pressure" or "constant roller gap" are often used, and each control mode has its own advantages and disadvantages. In a technical upgrading project of a raw meal grinding system, two control system programming languages were unified, and for the first time, a dual control mode of "constant pressure" or "constant roller gap" that can be switched online with one click was achieved. A comparative analysis was conducted on the system output, power consumption, material screening data after grinding by roller press, and economic benefits of the project under different control modes. Analysis shows that under a single control mode, there may be a problem with the effectiveness of the roller press operation, and the use of a dual control system can adapt to production needs under different conditions. At the same time, a visual roller press operation protection and inspection prompt program has been developed to improve the timeliness and comprehensiveness of cement factory (especially foreign users with weak technical capabilities) inspection and maintenance of roller presses.

It introduces the structure of the traditional bucket elevator and the problems existing in it, such as high construction accuracy requirements, long construction period, poor stability, and large potential safety hazards. The improvement idea of adopting an integrated modular design is proposed. The integrated modular bucket elevator is mainly composed of a bottom module, a head module, a non-standard shell module, and external platform module; and each module has been subjected to finite element mechanical analysis and is completed in the factory for production and pre-assembly. It has the advantages of standardized components and strong production flexibility, short installation period, and stable and reliable structure; and it can meet the diverse and personalized needs of customers, especially suitable for the upgrading and transformation of old plants and the construction of new production lines with short construction period requirements.

The main body and grinding body of a large tube mill have a large load and high grinding power. When its driving device adopts a central transmission method of planetary reducer and toothed coupling, it will generate significant axial force, which affects the stable and reliable operation of the mill. The process characteristics of large tube mill drive devices using central drive, single edge drive, single edge dual drive, dual edge drive, multi-point edge drive, and other driving methods are analyzed and compared. A certain project of the a ?5.2m large tube mill with 2×4 000kW double edge transmission system taken as an example, this paper introduces the selection, design and calculation of the main motor, reducer, girth gear, and pinion, as well as the practical application of the double edge transmission system. Production practice has shown that choosing the double edge drive method for large tube mills is a preferred solution due to its convenient installation, low cost, high transmission power, and stable and reliable operation.

There are some problems in HRM3400B raw meal vertical grinding system of a 5 000t/d cement clinker production line, such as high power consumption, high resistance, low operation efficiency, high comprehensive moisture content of grinding materials, many air leakage points of the system, large air leakage and so on. And then it are upgraded by optimizing the structure of cyclone inlet, heightening the inlet and upper shell of whirlwind cylinder, lengthening the inner cylinder of whirlwind cylinder, adding hot air pipe, increasing the angle of grinding sliver, adding buffer box at the end of slag discharge belt conveyor, replacing the grinding roller seal cover with a new type of internal labyrinth seal cover, removing the lower pressure reamer of cyclone tube and replacing it with unpowered flip plate valve, replacing all the dust collector cylinders with stainless steel materials, etc. After revamping, the pressure difference of raw meal vertical grinding machine is reduced by 183Pa, the oxygen content of waste gas at the end of online kiln is reduced by 1.8% and 2.0%, and the power consumption of mill is reduced from 16.33kW.h/t to 13.70kW.h/t. The production cost is effectively reduced and the transformation effect is remarkable.

In response to the high energy consumption index of the pyro system in the 5,000t/d cement clinker production line, including issues such as high clinker temperature exiting the grate cooler, high CO concentration at the outlet of the decomposition furnace, low heat recovery efficiency of the grate cooler, and low dust collection efficiency of the preheater, this paper proposes a retrofit plan for the preheater system's pressure reduction and capacity expansion, as well as the grate cooler. By taking measures such as expanding the capacity of the decomposition furnace, increasing the inner cylinder height of the C1 cyclone, modifying the connection structure of the C3 cyclone, and lowering the position of the tertiary air duct into the decomposition furnace; changing the fixed grate plate form at the front end of the first section of the grate cooler to an overall structural module for air supply, and designing the grate slot at the front end of the grate plate into a downward flat S-shaped structure, the system pressure reduction effect is significant. After the retrofit, the negative pressure at the outlet of the preheater decreased from 5 300Pa to 4 750Pa, the dust collection efficiency of the system increased to 95.6%, the standard coal consumption of clinker decreased by 3.4kg/t.cl, and the temperature of clinker exiting the grate cooler decreased by about 50°C, achieving the expected retrofit effect.

The 2 500t/d cement clinker production line of a cement enterprise has problems such as poor wearability of clinker, large ammonia dosage, and high exit temperature of preheater C1. By calibrating the inlet temperature, pressure, discharge temperature and gas composition in key parts of the cyclone cylinder within the preheater of the pyro system, the problems existing in the operation of the preheater system are analyzed. Technical reform schemes such as optimizing the pulverized coal pipeline of the calciner, transforming the structure of the kiln inlet chamber and the C4 sprinkler plate, improving the shrinkage gas velocity, improving the horizontal section of the cyclone cylinder and the gooseneck pipe of the calciner, and adding a stepped pre-combustion furnace. After the transformation, the exit temperature of the preheater C1 was reduced from 340℃ to 320℃. Under the condition that the NOx emission concentration remained unchanged at 45mg/m³, the amount of ammonia water consumption was reduced from 4.5kg/t.cl to 2.6kg/t.cl, the ammonia escape <5mg/m³, and the operation of the rotary kiln system was stable.

A 6 500t/d cement production line is equipped with a 132kV/6kV main substation and a 12MW waste heat generator set (WHGS). In the event of an external power grid failure, the WHGS will be operated as an isolated grid power supply. This paper analyzes the issues in the existing power distribution system, including its inability to automatically distinguish and switch the operation mode of grid connection and isolated operation, as well as its lack of self-protection in the event of external power grid failure. We propose a solution to build a coordinated machine-network control system (CMNCS) for "power supply, power grid, and load", and introduces the functional composition and structural components of this system. When the external power grid fails, CMNCS can quickly switch to the appropriate power grid operation mode, automatically implement secondary frequency and voltage regulation control to ensure stable operation of the distribution system.

This paper introduces the calculation method of using the practical torque formula of the electric motor to calculate the resistance value of the liquid starter in cement plant for large equipment like large mills. Taking a ball mill as an example, the comparative analysis was performed for the accuracy of the initial external resistance value and the starting time of the motor using motor practical torque formula and reference calculation formula in the liquid starter manual. The resistance value calculated by the motor‘s practical torque formula is more accurate, and the motor start time is shorter, which can be selected and determined, make full use of the motor‘s electromagnetic torque characteristics, reduce the starting impact process, and make the equipment run more stable. And at the same time, it can effectively improve the heating situation of the liquid starter and shorten the commissioning time. It should be noted when calculating the starting time of the square-torque load such as the fans, the starting time can be approximately calculated by using the average load torque.

This article analyzes the problems of overheating in waste heat boilers, such as Increased boiler pressure can easily cause explosions, deformation of metal components may lead to collapse accidents, the decrease in pressure bearing capacity of pressure bearing components can easily cause problems such as pipe bursts or leaks. Taking the grate cooler as the object, the equation for thermal equilibrium was listed, and the reasons for the overheating of the waste heat boiler were analyzed; It is proposed to increase the air volume of the high-temperature section of the grate cooler, increase the air volume of the second and third air, reasonably control the grate speed of the grate cooler, reasonably select and maintain the refractory and insulation materials of the waste heat boiler, upgrade the materials of pressure bearing components, add waste gas pipelines and steam pipeline temperature reducing devices, and regularly conduct metallographic and non-destructive inspections of steel components and other safety measures. To avoid overheating of the waste heat boiler from the source, it is necessary to reasonably regulate the firing process, configure the air supply at the head and tail of the cement kiln, stabilize the firing system working conditions, ensure stable operation of the waste heat boiler under safe working conditions, and extend its service life.

The cement kiln online thermal calibration system is based on the MES production execution and control information system. Through intelligent instruments and meters, it continuously collects, stores, and cleans production operation data online, regularly completes thermal index accounting, and outputs calibration reports. The network architecture, data collection sources, measurement methods, and calculation basis of the online thermal calibration system were introduced, as followed, the achievable system functions were list. And then the calculation process of core thermal indicators such as primary air flow at the kiln head, cooling machine drum air flow, system air leakage, C1 outlet dust concentration, and clinker formation heat were explained. At last it was applied an online thermal calibration system in Huaikan South project to quantitatively compare and analyze the thermal efficiency of the cooling machine before and after maintenance in March 2023. The thermal efficiency of the cooling machine increased by 3% to 4%, and the results of online thermal calibration analysis were highly consistent with manual analysis, achieving a transformation from offline thermal calibration to online thermal calibration.

The MEA (ethanolamine) chemisorption technology commonly used for the capture and purification of CO₂ gas in industrial kiln exhaust gas was introduced, including the process flow of external heating rotary kiln and vertical kiln direct capture and purification technology, main equipment and research and development process. The key points focus on comparing the application status of chemical adsorption technology and externally heated rotary kiln capture technology in the domestic cement industry. For chemical adsorption technology captures and purifies CO₂ gas, the quality of the product is poor and the production cost is higher with the payback period >10 years. Comparably, for externally heated rotary kiln capture technology, it can directly capture CO₂ produced by thermal decomposition of carbonates, the product is of high quality with low energy consumption and short payback period of only 3~4 years. A externally heated rotary kiln capture technology was applied in a cement production line, where the specifications of rotary kiln ?(2.2~2.8)m×65.8m. It can capture and purify food-grade liquid CO₂ more than 6.0×10⁴t per year, at the same time, it can produce lime powder (CaO) more than 15.3×10⁴t per year, achieving a higher payback on investment and bring a broad  promotion and application prospect.

In the execution process of a 7 500t/d cement clinker production line EPC project， BIM platform is used to implement the overall planning of project construction， divide construction and installation areas， simulate construction site layout and construction， rationally arrange the general construction plane， strengthen equipment quality management， construction quality and schedule control， and implement intelligent safety management. It also has achieved the reasonable arrangement of equipment and material storage， non-standard parts production site， strengthening cost control management， etc. The project construction started at the beginning of the year， put into production in the year， and made good economic and social benefits.

The compressive strength of cement clinker is one of the most critical control indicators in cement production. The morphology, types, and content of minerals contained in cement clinker were obtained through petrographic analysis, diffraction analysis and Jinde calculation method. Analysis shows that different types of minerals play different roles in the hydration process of cement clinker. Different forms of the same mineral have different hydration effects on cement clinker. The uniformity of the distribution of the same mineral also affects the compressive strength of cement clinker. The morphology, content, and uniform distribution of the main minerals play a crucial role in controlling the compressive strength of cement clinker. Excessive free calcium and periclase are detrimental to the formation and crystal development of the main minerals in cement clinker. When the alkali content is high, it will lead to a decrease in the compressive strength of cement clinker. To improve the compressive strength of cement clinker, it is not only necessary to control the content of the main mineral components, but also to pay attention to the crystal development of each mineral component and the sodium and potassium content of the raw materials.

Through experiments, various situations have been analyzed that may lead to a decline in cement quality when desulfurized gypsum is used as a cement retarder, including potential issues such as excessive levels of Cl^-, ammonium salt, and semi-hydrated calcium sulfite content, as well as desulfurized gypsum dehydration. It is proposed to pay attention to changes in desulfurization technology of coal-fired power plants, conduct harmful component content testing of raw materials entering the factory, and adopt measures such as reduceing the temperature of cement entering the warehouse, avoiding dehydration of desulfurized gypsum in the warehouse, to ensure the quality of cement products.