【Weekly Question】How can the quality of coke produced by coke ovens that are over 20 years old be ensured? (November 22---November 26)

Severe leakage in the carbonization chamber! There is a large temperature difference after coal loading and during coke extraction!

The resistance in the regenerator increases, affecting the suction force； Solution: Remove the sealing wall of the regenerator and replace the grid bricks; leakage in the furnace wall affects normal heating ； Repair promptly: The bricks used in gas lamp holders are damaged, and the pore sizes are uneven, which affects temperature uniformity ； Replacing the lamp head brick causes the slope opening to become smaller or larger, which affects the flame height and temperature, resulting in uneven coking ； Use inclined passageways or add tongue bricks, etc

I really haven’t encountered furnaces with a service life of 15–20 years like ours; those with a longer lifespan are very rare. As for the furnace mentioned by the original poster, which is 26 years old – is that allowed? Such coke ovens must have a significant impact on the environment. :handshake

I was in charge of a facility for 39 years; the main problem there was severe smoking and burning of the furnace bricks on the machine side. To address this, we used patching methods, as well as increasing the weight of the iron components used to protect the furnace.

Furnaces that have been in use for a long time suffer from severe leakage; the lamp bricks and inclined channels are also damaged. The iron components have aged, and the flanges of the rising tubes, bridge tubes, main tubes, etc., as well as these components themselves, have reached their limit of usability. The furnace walls need to be repaired, the temperature distribution needs to be measured accurately, and adjustments should be made based on those measurements. Some of the replaceable iron components need to be replaced.

I’ve only just begun to understand coking furnaces, but I’ve seen many old high-temperature devices; the problems they have include outdated firmware, severe scaling, and many components that do not meet the requirements of the equipment – they are barely functioning! There won’t be any major problems with the furnace itself; it’s just aging and scaling, so it needs to undergo a major maintenance overhaul once! Replace the components and pipelines that need to be changed, and clean whatever needs cleaning, especially the equipment inside the coke oven and in the cold drum section!

For furnaces over 20 years old, aging occurs in the iron components and the furnace body. If there is leakage along the furnace wall, it will affect normal heating ； Air may leak in, increasing the ash content of the coke. Additionally, there are significant changes in the resistance of elements such as the rising flue and regenerator. Gas equipment and furnace fittings may need to be repaired or replaced promptly.

Speaking of the problems with old furnaces, we only removed a 2.8-ton furnace back in February of the year before last; it was built in 1971 and had numerous issues. First of all, holes kept forming in the furnace wall on the machine side – at first they were plugged manually, later using a semi-dry method. More and more holes appeared, and a large amount of bricks and gravel fell into chambers 1 to 4, blocking them. The furnace wall on the machine side also deformed and bulged, which affected the process of pushing coke out. Eventually, no one paid any attention to it anymore, and we just continued to use it as it was

Of the posts above, only the one on the 3rd floor is decent; the rest are just superficial and based on incomplete understanding. Looking forward to high-quality posts. :lol

Moderator: Regarding your discussion topic, it should be a combined issue, because if the furnace is well maintained and managed, the quality of coke will also be guaranteed. As the furnace age increases, problems such as wall erosion, cracks in the furnace walls and ceiling bricks, increased furnace length, deformation of the furnace walls, cracks caused by wear of the bottom bricks, and melting of the bricks in the combustion chamber occur. The reason for this is the following reaction: SiO2 + C ---- SiO + CO. In the later stages of operation of a coke oven, emphasis is placed on operation, management, and maintenance, as detailed below: First, three-shift operation is required, along with proper cleaning of the furnace doors and frames, to prevent incomplete coal loading in the carbonization chamber and negative pressure conditions during operation. Second, strictly implement the coke pushing plan, strengthen furnace temperature control, maintain mechanical equipment properly, remove graphite from the furnace walls in a timely manner, establish a maximum coke pushing current; in case of difficulties in pushing coke, identify the causes to prevent damage to the furnace. Third, strengthen the management of iron parts to determine an appropriate furnace column curvature. Fourth, determine an appropriate coking time; for coke ovens with a long service life and poor operating conditions, the coking time should be appropriately extended. Fifth, it is necessary to carry out proper routine maintenance, establish sound inspection and repair systems to ensure the integrity of all parts of the furnace; the heating process must be such that the furnace temperature remains uniform and stable. Any areas where there are leaks or blockages should be repaired and cleaned to ensure that the coke matures evenly and on time.