The significance of the core temperature of coke cakes and the risks associated with its measurement

“To prevent accidents during operation, the following specialized tools and detailed procedures have been developed to ensure a safe and smooth execution of the tasks. ”Where’s the thing? ? ?

Could the original poster introduce the \"specifically designed tools and detailed procedures\"?

Detailed steps will be provided upon request: No graphic is available for copying at the moment. 1. Purpose of measurement: The temperature at the center of the coke cake is an indicator of the maturity of the coke, and it also serves as the basis for determining the standard temperatures in coke ovens. To determine whether the established standard temperature is reasonable, the uniformity of coking cake maturation along the length and height directions of the carbonization chamber was examined. It is necessary to select a furnace number with normal heating, and measure the temperature at the center of the coke cake half an hour before coke pushing. Three points – upper, middle, and lower – are taken from each coke cake on the machine side of the carbonization chamber, and the temperature at each point is measured. The average value of these temperatures is taken as the temperature at the center of the coke cake. The temperature differences between the upper and lower parts of the coke cake are also calculated; the smaller this difference, the better the quality of the coke cake. Generally, the temperature difference between the upper and lower parts of the coke cake should not exceed 100°C, and the final temperature at the center of the coke cake should be maintained at 1000–500°C. Under normal production conditions, the temperature at the center of the coke cake is required to be measured once per quarter. It should also be measured when the type of heating gas is changed, the coking time is altered, the standard temperature is changed, there are significant variations in the coal blending ratio, or when there are large fluctuations in the furnace temperature, in order to check and adjust the standard temperature based on the temperature at the center of the coke cake. Hazardous risks: When measuring the core temperature of coke cakes in our plant, we generally insert a specially designed measuring tube into the side of the coke in the furnace; the specific point inside this measuring tube is used to represent the core temperature of the coke cake. Due to the long length of the pipes, the process of inserting and removing them as well as carrying out measurements involves risks such as high temperatures, working at great heights, exposure to electricity, and interference with other types of work. In particular, the traditional methods of removing pipes involve multiple people working at heights on coal trucks; after removing the pipes, they end up too close to the hot pipes and the open furnace mouth, which increases the risk of burns. To prevent accidents during operation, the following specialized tools and detailed procedures have been developed to ensure a safe and smooth execution of the tasks. 2. Fabrication of measuring instruments (applicable to 4m coke ovens) 2.1 Fabrication of coke cake center temperature measurement tubes Two coke cake center temperature measurement tubes are generally used in 4m coke ovens, and they are made from seamless pipes with an inner diameter of 67 mm. The manufacturing method is as shown in the figure below (total length: 4.95 m): A–A represents a regular hexagon with a hollow space in the middle, which is welded around the tube using steel plates. At points B and C, 16# round steel bars are inserted into the tube to a depth of 3 cm; it is required that points B and C be perpendicular to each other. The steel pipe is required to be straight with a smooth surface; the D section forms a constricted tip, which must be dense to prevent air leakage. 2.2 Special furnace mouth covers and tools for measuring the coal line and coke line 2.2.1 Special furnace mouth covers, as shown in the diagram: circular covers with a thickness of 10 mm, featuring a small hole in the center whose diameter is equal to that of the furnace mouth. 2.2.2 Tools for measuring the coal line and coke line. As shown in the figure, for seamless pipes with a diameter of less than 4 mm and a height of more than 2 cm, scales are marked from 1.3 m to 2 m from the lower end; the minimum scale division is in cm. During use, the B plate is inserted into tube A from above, and tube A is then held and inserted into the furnace mouth (after coal has been loaded or after coking) so that the distance between the coal or coke and the B plate can be measured. 3. Construction of safety tools for tube removal: When removing the tubes used to hold the coke cakes, due to the long length of these tubes, a certain height is required. We usually make use of coal loading carts; rocker arms are installed at appropriate positions on both sides of the cart’s mechanism related to the coke handling. The height of these rocker arms should be more than 5.5 meters above the surface of the furnace top, and below the position of the coal discharge opening, so as to avoid hitting it. As shown in the diagram: Tube A is inserted into tube B; both tubes A and B can rotate. Points C and D are the screws used to fix tube A, while E is a ring onto which a pulley can be attached. 4 Preparation of auxiliary tools: one fixed pulley, a large hammer, a rope with a hook at one end (20 meters long), two long hooks and two short hooks, and two small iron plates. 5 Insertion: The shift leader in charge of flame adjustment designates the furnace number in the carbonization chamber (calculating the time required for tube removal). When coal is loaded into that furnace, the signalman is instructed to level the coal carefully to ensure there are no obstructions or blockages, and that it is evenly spread out. After coal loading is completed, measure Coal Lines 1#, 2#, and 3# separately and record the values. Then, intubation begins: the No. 2 coal loading port is covered, and special furnace lids are placed over Nos. 1 and 3. The pre-prepared temperature sensor for the coke cakes is inserted into these openings, with the steel tube being positioned vertically along the center line of the carbonization chamber. If it is not aligned properly, it must be reinserted; it needs to reach the bottom, and its exposed part must not touch the coal loading vehicle. After insertion, the tube openings are covered with two small iron plates to prevent debris from falling in. 6 Measurements 6.1 Eight hours after coal loading, the temperature of the horizontal rows on both sides of that carbonization chamber is measured once (usually by the temperature testers on the third shift at 0:00). 6.2 Two hours before coke pushing, an optical pyrometer is used to measure the temperature at the center of the coke cake on the machine side as well as the temperatures at points B, C, and D inside the tube; these measurements are taken every half hour. Once more, the temperature of the horizontal rows in that carbonization chamber is measured one hour before coke pushing. The cokemold temperature was measured four times in total, with each reading recorded separately. 7 Tube Removal: When removing the tube, operations must be directed by a dedicated person; typically 10 people are required to carry out this task following these steps: 7.1 Open the rising pipes on both sides. 7.2 Use the hook used to lift the furnace lid to turn the coke cake pipe slightly, thereby loosening it. 7.3 After positioning the coal cart in the appropriate place, an electrician shall cut off the power supply to the sliding wire connected to the coal cart, with another person assigned to monitor this. 7.4 Assign one person to the coal cart to secure the arm in place (being careful of the sliding wire above), adjust its direction, attach pulleys, and fix the ropes. 7.5 Hang the end of the rope with the hook onto the coke cake pipe; two people should hold long hooks ready to hook the pipe. Once all preparations are complete, the supervisor gives the command to start pulling the rope and remove the pipe. 7.6 After the coke cake pipe is removed, two people using hooks keep it from swinging around; slowly release the rope and place the pipe gently on the surface of the furnace top. 7.7 One person uses a short hook to pull the coke cake pipe to the end platform, while another person uses a sledgehammer to gently straighten it, ensuring there is no bending and avoiding any damage to the pipe, so that it can be used again in the future. 7.8 After both pipes have been removed, measure the temperatures at points upper, middle, and lower on the walls of chambers 1#, 2#, and 3#, and record these values. Then store the ropes and pulleys properly. 7.9 The person on the coal cart should secure the arm so that it cannot rotate freely; once the coal cart has been moved away, inform the electrician to restore power supply and resume normal operations. 8 Measurement of the Temperature on the Walls of the Carbonization Chamber: The temperature of the walls of the carbonization chamber is usually measured simultaneously with the temperature at the center of the coke cake. After all the coke has been removed from the furnace, align the furnace doors on both sides, open the covers of the rising pipes, and measure the temperatures at three points—upper, middle, and lower—on the inner walls of both sides, recording each value separately. Upper point: Equivalent to the turning point of the combustion chamber flame (700~800 mm from the top of the carbonization chamber). Midpoint: The middle point between the upper and lower points. Lower point: The second or third layer of bricks from the bottom of the carbonization chamber. Measurement method and sequence: Start measuring from coal loading port No. 3; at this time, the other two coal loading ports should be covered. Measure the temperatures at 6 points in total on the upper, middle, and lower sections of the walls on each side. After completing the measurements, open coal loading port No. 2, cover No. 3, and then measure Port No. 2 again. Continue in this manner until all measurements have been taken and recorded. When measuring coal loading port No. 1, cover Ports No. 2 and No. 3, take the measurements, and record them. 9 Data processing: Record the data and calculate it to fill in the table; the average value of the center temperature of the coke cake at the last measurement is the center temperature of the coke cake. Furthermore, by conducting a comprehensive analysis based on the data obtained from loading flat coal, pushing out coke, and observing the flame and coke cake conditions at the furnace mouth, rising pipe, furnace door, etc., conclusions regarding the measurement of the center temperature of the coke cake are drawn. Appendix: Record sheet for the center temperature of the coke cake and the wall temperature of the carbonization chamber. This post was last edited by wzf1830 on 2008-11-7 10:44.]

Also, in addition to taking measurements on the top of the furnace, it is necessary to use infrared sensors to measure the temperature at the coke side as well; by comparing the temperatures from both methods, patterns can be identified

I have learned the method used by Haiyou on the 4th floor to measure the center temperature of coke cakes, but I don’t understand why only the average temperature of the last measurement is taken into account in the calculations Also, what is the purpose of the coal line and coke line recorded during measurement?

Reply to 1# wzf1830: The core temperature of coke is an indicator of its maturity, and it also serves as the basis for determining the standard temperatures in coke ovens. Select a furnace with normal heating; after loading coal, insert a special measuring tube into the coal loading port on the machine side of the coke, and measure the temperature at the center of the coke cake half an hour before pushing out the coke. Generally, the temperature difference between the upper and lower parts of the coke cake should not exceed 100°C, and the final temperature at the center of the coke cake should be maintained between 950–1050°C. Under normal production conditions, the temperature at the center of the coke cake is required to be measured once per quarter. It should be measured whenever the type of heating gas is changed, the coking time is altered, the standard temperature is changed, there are significant variations in the coal mixture ratio, or there are large fluctuations in the furnace temperature, in order to check and adjust the value based on the standard temperature. Potential hazards include burns, electric shock, and crush injuries