【Q&A on the Production Operations of Haichuan Coke Ovens】11. How to deal with gas leakage in the brick gas channels?

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This post was last edited by HaiChuanLaoYu on 2026-5-25 07:36. 10. How to turn down the small stove? Answer: The method for flipping the small burner is as follows: (1) Remove the old bricks, extract the asbestos rope and graphite between the protective plate and the bricks, and blow them clean with air. (2) Grout the protective plate to fill the space, reinsert the asbestos rope (diameter 33mm or 30mm) soaked in a sodium silicate-clay mortar mixture and secure it firmly, smooth it with mortar, and reinstall the small stove brick. (3) The brick joints of the internal retaining masonry should be sealed tightly with a relatively dry water glass-clay mortar; a gap of about 10–15 mm should be left between the small burner and the steel column to facilitate future repairs. (4) The surface of the masonry should be smooth; the brick joints on the outer surface should be filled again using water glass, clay, or fireclay, and their elevation should be slightly lower than that of the furnace roof surface. 11. How to deal with gas leakage in brick gas ducts? Answer: Leaks in the horizontal brick gas channels mostly occur at the points where the temperature changes sharply in the 2nd to 3rd burners of the stove. By reducing the pressure difference between the brick gas channels and the adjacent sections, gas leakage can be eliminated. Therefore, after a coke oven has been in use for a long time, it is possible to lower the pressure in the brick gas channels by using burners with a larger cross-sectional area, thereby reducing the pressure difference between these channels and the adjacent regenerator sections. However, this often results in insufficient heating in the side channels. Before repairing the horizontal brick gas duct, it is necessary to identify the location of the leaks. This can be done by removing the end cap of the brick gas duct when no gas is flowing, and using colored glass for observation; flames resulting from the combustion of gas that has leaked in from elsewhere can often be seen at the site of the leak. General leaks are repaired using a small trowel or by spraying; the spraying pressure must be controlled to prevent flames from entering the flue or to avoid clogging the burner. In cases of severe leaks, grouting is also used as a repair method. After repair, proper cleaning is necessary. When cracks appear in the downward-fired brick gas channels or the grout between them widens, gas can leak from these channels into the regenerator and the small flues (especially those at the lower part). This can lead to problems such as ignition below the exhaust gas tray, melting of the grid bricks, as well as damage to the walls of the regenerator and the low-temperature sections of the flues. If the gas channel of the standing brick is not airtight, it can be fixed by grouting with fine powder; the grouting pressure should generally not exceed a certain level, to prevent mortar from entering the flame channel. Depending on the location of the leakage, different pressures should be applied to cause the slurry column to move up and down at the leakage site, thereby filling the cracks completely. The particles of the grouting mud should not be too coarse; otherwise, if the slurry is too thin, it will settle and cause blockages, while if it is too thick, it is difficult to control the pressure and it won’t be able to penetrate the cracks. When the vertical brick gas duct is blocked by graphite, it can be pried open with a steel rod; in cases of severe blockage, the thread plug at the bottom of the vertical pipe can be removed first, and after one or two exchanges, the duct can be pried open. When the brick gas ducts become blocked due to swelling caused by the clay mixture and bricks, oxygen can be blown in using an iron pipe to melt the blockages. However, it is necessary to seal them tightly before blowing in oxygen to prevent gas from leaking out and mixing with oxygen, which could cause fires and explosions. Additionally, the oxygen pressure must be controlled so as not to melt the silica bricks. When the integrity of the small flue masonry is compromised, the vertical brick flue should be sealed first, and then the small flue masonry should be sealed using the waste gas tray.