【 Computer Automatic Monitoring System for Coke Oven Heating】

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This post was last edited by hao101029 on 2012-2-17 at 21:24. In recent years, China’s metallurgical industry has developed rapidly, which has led to swift progress in coke production; many new coke ovens are under construction or have already been built. However, due to the short duration of the oven drying process and the difficulty of utilizing the equipment once drying is complete, there isn’t much research being done on the automation of this process. To address these issues, our company successfully completed the development of relevant technology in 2007. To date, this system has been used to successfully carry out furnace drying services for over twenty coke ovens. I. Process details: The drying of a coke oven involves using heat carriers with different compositions to dry and heat the constructed oven, thereby raising its temperature as planned and ensuring uniform expansion of the structural elements. The oven goes through two stages – drying and temperature increase – until its temperature reaches around 850 °C at which point internal heating begins. The quality of this drying process is crucial for ensuring that the coke oven can operate stably, with high productivity, and for a long duration. Therefore, in the heating up of coke ovens, formulating a heating plan and a heating curve based on the temperature characteristic curve of silica bricks is the first step in this process; controlling the heating process according to that curve is key to determining the quality of the oven heating. The formulation of the coke oven heating schedule begins with calculating the number of days required for heating at each temperature interval, based on the expansion curve of the bricks, the temperature distribution across various parts of the coke oven, and the specified daily expansion rate. Once these values are determined, the daily temperature increase and daily expansion rate for each temperature interval are calculated, and these values are presented in tables as well as illustrated through curves showing the temperature and expansion trends. II. Setting of temperature measurement points: Depending on the type of fuel used for heating, there are solid-fuel heaters, liquid-fuel heaters, and gas-fuel heaters. Gas-fuel heaters offer advantages such as easy temperature control, precise adjustments, and labor savings. Generally, older metallurgical plants or those with the necessary facilities use gas-fuel heaters. The temperature measurement points are arranged as follows (taking a 55-chamber coke oven as an example):
Temperature measurement locations and points:
– Temperature in the combustion chamber: Channels No. 08 and 25 in each combustion chamber.
– Temperature in the management channels of the combustion chamber: Channels No. 01, 02, 06, 11, 16, 21, 31, 36, 41, 46, 51, 55, 56 in combustion chambers 01, 03, 14, 19, 30, 32.
– Temperature in the horizontal rows of the combustion chamber: Channels No. 1 to 32 in combustion chamber No. 26.
– Temperature in the regenerator: Regenerators No. 01, 02, 06, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 57.
– Temperature in the small flue ducts (or grate bricks): Same as that of the regenerator.
– Flue duct temperature: Temperatures in the flue ducts on the machine side and the coke side, as well as the total flue duct temperature.

III. Main functions of the software:
(1) It displays the actual temperatures at all measurement points in the form of a map showing the actual locations of these points, with different colors used to distinguish between different temperature ranges. (2) Visually display or print the current temperature of all measurement points or each individual measurement point in the form of graphs, charts, or curves. (3) Display or query the actual temperature rise curves and temperature reports for any given day for the straight-through temperature, the temperature on the machine side during straight-through operation, and the temperature on the furnace side during straight-through operation. (4) Display the planned temperatures for the combustion chamber, regenerator, and small flue (or grate bricks). (5) Calculate the current average temperature of the entire furnace, as well as the average temperatures on the machine side and the coke side. (6) Query and display or print, in the form of reports or curves, the temperature data and temperature variation trends of any measurement point at any time during the furnace heating period. (7) Display the actual temperature rise curves and planned temperature rise curves for the combustion chamber, regenerator, and small flue (or grate bricks), respectively. (8) Query the actual temperature rise curves and temperature reports for any given day in the combustion chamber, regenerator, and small flue (or grate bricks). (9) Calculate and generate daily reports for the combustion chamber, regenerator, and small flue (or grate bricks); the report should include temperature data at 3 o’clock, 7 o’clock, 11 o’clock, 3 p.m., 7 p.m., and 11 p.m. (10) Displays the temperatures of the main flue and the flues on the machine and coke sides. (11) Measure the suction pressure in the main and branch flues, atmospheric temperature, and gas pressure once per hour, and input them into the computer. (12) Data is collected at each temperature measurement point every 5 minutes, and all collected data is archived. (13) All reports can be converted to Excel format. IV. Characteristics of the oven heating system The oven heating system has the following characteristics compared to the conventional control systems that we use regularly: 1. There are many measurement points, most of which are temperature sensors. 2. The measurement points are scattered, located across the entire furnace top and on both sides of the furnace. 3. The volume of data to be processed is large, requiring real-time calculations such as summing and averaging hundreds of data points. 4. The amount of data stored is large; during a normal baking cycle, the computer collects over 5 million data points which are then stored in the database. V. Equipment Selection: A regular computer is used as the device for data storage, processing, and display. Thermocouple acquisition modules located at the top of the coke oven and on both sides of it are connected through RS485 distributors, forming a distributed system. This approach is suitable for situations where the measurement points are spread out over a large area. Its advantages include a decentralized layout, low space consumption, low failure rate, ease of maintenance, and minimal impact on the construction of the oven’s thermal systems during later stages. For detailed information, please contact us within the site to request it