【Q&A on the Production Operations of Haichuan Coke Ovens】13. How to clean the chutes, and what should be done in case of blocked chutes?

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12. How to repair damage to the furnace bottom of a carbonization chamber? Answer: When replacing 1 to 3 furnace bottom bricks at the furnace end, generally, the coke in about one combustion channel is removed at the initial stage of coking. Thin insulation panels and medium-thickness insulation panels are attached to the front side of the coke as well as to the lower halves of the exposed wall surfaces on both sides, and fixed using flat support brackets. Break the damaged furnace bottom bricks, remove them and use compressed air to blow away any remaining residue, then pour in a slurry of clay fireclay prepared with phosphoric acid. Place the preheated new furnace bottom bricks in place and adjust their height so that it matches that of the adjacent bricks. A large number of end furnace bottom brick kilns need to be replaced. The area for replacing the furnace bottom bricks extends beyond 3 burners at the ends; therefore, the furnace must be emptied, a temporary furnace door with a small door at the bottom must be installed, and all coal loading covers must be opened to create a slight negative pressure in the lower part of the carbonization chamber. Remove the small door; follow the same steps as above. Abroad, there are air-cooled insulated boxes that are pushed into the carbonization chamber; repair workers enter the box, remove the movable plates corresponding to the damaged sections of the masonry, and carry out repairs through those openings. 13. How to clean the inclined chute, and what to do with dead chutes? Answer: A small amount of debris such as bricks, coal dust, and fireclay may fall into the chute, affecting the distribution of air flow. Before cleaning, it is necessary to check whether the tools are damaged, to prevent any parts of them from falling into the flue. For the brick dust and debris inside the chute, an iron chain or an iron scraper or prying tool can be used to reach inside the chute and clean it back and forth along its length; alternatively, an iron rod can be used to break the bricks apart before removing them. When the flue is severely blocked by coal powder coming from the carbonization chamber and coke forms, coke oven gas and compressed air can be introduced through an outer pipe to burn at the inclined channel entrance, thereby burning off the coke and removing the remaining ash. After the chute becomes blocked and other methods prove ineffective, one can enter the furnace and remove the blockage by drilling and scraping. To prevent the furnace wall from being exposed to the atmosphere and causing excessive temperature drops, enclosing walls or barriers must be constructed; the furnace wall should be covered with insulation panels and secured using flat supports. The grid bricks at the top of the regenerator are covered with iron plates to prevent ash and slag from falling into the grid bricks. Then, break through several layers of wall bricks at the bottom of the dead coking chamber, remove all the coke and ash, and clear the access ramp. Fill the opening at the bottom of the furnace wall, remove the supports and insulation materials inside the carbonization chamber, and pull out the cover plates on the grid bricks along with any debris, then increase the temperature at the door.