Regenerator grid brick replacement plan (uploaded at everyone’s request)

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Plan for removing several layers of grid bricks from the top of the regenerator chamber of Coke Oven No. 2: In our plant, gas leaks occur on the gas side of the upward airflow in certain areas of the waste gas collection system of Coke Oven No. 2, due to issues such as weights and rods. To completely resolve this problem, while ensuring that production is not affected, this plan involves only the removal of some of the grid bricks; it does not include the replacement of a large number of grid bricks, nor any repairs to cracks in the silica brick walls of the regenerator chamber. A specific plan has been developed for removing some of the grid bricks from Coke Oven No. 2. I. Preparation of construction tools and materials: 1. Personal protective equipment and safety gear, carbon monoxide detectors, low-voltage lighting, as well as fans for use in the regenerator corridors and on the temperature measurement platforms. 2. Iron plates: to cover the areas where waste gases accumulate, and also to cover the lower grid bricks during their removal. 3. Insulation panels made of aluminum silicate fiber or other asbestos-based materials. 4. Special tools for removing grid bricks, pry bars, flexible shovels, and porous compressed air nozzles for cleaning. 5. Refractory mortar and insulation materials (for insulating the walls). II. Conditions that must be met before replacing the grid bricks: 1. Since only a small area of the grid bricks needs to be replaced, there is no need for significant cooling, nor is there any issue related to insulating the furnace when the relevant carbonization chambers are empty. 2. The carbonization chamber corresponding to the regenerator, which is to have its grid bricks replaced, should be in the middle or late stages of coking. 3. Use coke oven gas for heating whenever possible, if conditions permit. 4. In accordance with the principle of matching pairs, close and replace the on/off valves on the gas pipes related to the lattice brick regenerator. 5. Before starting the actual construction, it is also necessary to have the flame adjustment operator check which valves in the heating system need to be closed and determine the carbon monoxide level in the construction area before proceeding with the actual work. III. Procedure for removing grid bricks: 1. Cover the exhaust tray with an iron plate to prevent broken bricks from blocking the exchange equipment and affecting its functionality. 2. Use a crowbar to remove the pressure measurement holes; when removing the bricks, try to keep the height of the removed bricks as consistent as possible, in order to minimize the impact of cold air from penetrating into the remaining bricks. 3. Use specialized tools for removing grid bricks to take them out; if they are melted, a flat shovel with a flexible handle can be used to break them apart and remove them. 4. Cover the area above the bricks that have been removed with an iron plate, to prevent debris from falling onto the bricks below. Move the iron plate forward as more bricks are removed from the upper layers. The peeling order is “from top to bottom, from outside to inside”. 5. After all the grid bricks in one layer have been removed, the iron plate is taken out, and an insulating board is placed in front of the remaining grid bricks to prevent cold air from leaking in. Porous compressed air is introduced from above and below the grid bricks through the cleaning holes to clean them and check for any dust particles in the air. At the same time, the condition of the bricks that have been removed is inspected to determine whether it is necessary to remove more grid bricks from the next layer until the passage is unobstructed. 6. After removing the bricks that need to be taken out, thoroughly clean the remaining bricks, and then construct the sealing wall along with the external insulation material. 7. After construction is completed, determine whether to open the corresponding burner valve adjustment cocks based on the temperature of the combustion chamber. Several notes: 1) If the lattice bricks are to be inserted while the system is in a hot state, their depth of insertion should be kept between 4 and 7 burners; otherwise, there will be issues with the quality of the stacking of the bricks inside. 2) The aim of using coke oven gas for heating as much as possible is to enable hot replacement of the grid bricks. In order to prevent excessive drops in the temperature of the combustion chamber due to prolonged processing times, it is possible to replace a certain number of grid bricks and then, based on changes in the combustion chamber temperature, resume heating to raise its temperature again, thereby protecting the bricks in the carbonization chamber and chutes. 3) If it is necessary to enter the regenerator after cooling the furnace for replacement, the cracks in the main and secondary walls of the regenerator must be sprayed and patched before grid bricks are placed (this has a significant impact on production and involves the issue of heating the furnace up; therefore, it is not considered in this plan). IV. Furnace temperature management before and after construction 1. Before starting the work, heating to the relevant furnace should be stopped. There are two methods for this: A. Only close the control valves for the heating coal gas pipelines in regenerator No. 46; wear a carbon monoxide detector while removing the partition walls to check whether the carbon monoxide level in the downward-flowing gas exceeds the permissible limit, and then decide whether to close the control valves for regenerators No. 45 and No. 47 as well. B. Close the control valves for regenerators No. 45, No. 46, and No. 47 all at once. 2. During the construction process, it is advisable to insert temperature-measuring thermocouples at appropriate positions on the top of the regenerator to ensure that the temperature of the regenerator remains above 700°C. One hour after the construction begins, the temperature of the corresponding combustion chamber should be measured; depending on the degree of temperature drop, the frequency of temperature measurements should be increased, especially for the temperature at the furnace head, in order to prevent excessive drops in furnace temperature. If this occurs, construction can be suspended, and coke oven gas can be used for heating for a while until the temperatures of the regenerator and combustion chamber rise again, after which construction can resume. V. Safety Precautions 1. When stopping and replacing the regenerator associated with a specific furnace number, ensure that the control valves for that furnace number are properly closed and that the correct furnace number is selected. 2. During construction, the fans in the regenerator corridor and on the roof temperature measurement platform should be kept running to maintain ventilation. 3. Be careful to avoid burns when removing partition walls or grid bricks. 4. During construction, a dedicated person should wear a carbon monoxide detector to monitor the gas concentration at the site. 5. When working on the roof storage platform, take care to prevent injuries to the head; the removed grid bricks should be stacked properly to prevent them from falling. 6. Access is prohibited in the regenerator corridors near the construction area to avoid injuries caused by falling objects.