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Solving the problem of Coke oven door smoke: Technical optimization of furnace doors for coking plants

Dear colleagues working in the coking plant, during the coking production process, smoke from the coke oven door not only affects production efficiency, but also causes pollution to the environment. This article will delve into common problems with oven doors in coking plants and propose optimization measures to help improve the performance of high-sealing coke oven doors and reduce smoke emission.

Coke furnace

1. Causes of smoke from furnace doors in coking plants

In daily coking production, the main reasons for furnace door smoke include: deformation or damage of the furnace door sealing edge, frame deformation, improper cleaning of the furnace door and frame, inaccurate furnace door alignment or clamping of coke during alignment, furnace door pressure equipment Damage etc.

1.1 Coke oven door problem

The coke oven door uses a self-sealing spring to seal the edge, and the pressure of the sealing edge against the coke oven frame is provided by the spring. The sealing edge can compensate for the difference in deformation between the furnace door body and the door frame. However, due to the poor working environment of the spring, high operating temperature, large load, short compressible stroke and limited spring compression, it is unable to produce an appropriate rebound effect, resulting in insufficient pressure on the coke oven frame from the sealing edge, and the deformation of the oven door body cannot be completed Deformation of the matching door frame, resulting in poor sealing and gas leakage.

The thickness of the original coke oven door mesh is 1.5mm. The mesh is thin and has poor toughness and strength. The butt welds at the four corners of the mesh will creep under high temperatures, resulting in gaps between the upper and lower transverse heads of the sealing edge and the four corners of the mesh. It changes with the change of the door frame. Over time, cracks will appear in the four corners and smoke will appear frequently. At the same time, damage to the furnace door during operation cannot be overcome.

After the coke oven door is removed from both ends of the carbonization chamber before coke is pushed, a large amount of tar will adhere to the surface of the refractory bricks of the oven door and in the sealed edge groove. The tar in the sealed edge groove and door corners is difficult to clean. If it is not cleaned frequently, the furnace door cannot ensure its sealing effect. During the coking process, a large amount of gas will leak from the groove on the sealing edge of the furnace door, seriously polluting the environment and wasting energy.

1.2 Furnace door brick problem

In order to increase the coal loading capacity of a single hole and thereby increase the coke output of a single hole, the thickness of the coke oven door brick was reduced from the original 378mm to 278mm, and the thickness was reduced by 100mm. In order to ensure the maturity of the burner head coke, the machine side coke oven gas nozzle plate was changed from the original 11.8mm and 12.5mm to 12.3mm and 12.5mm respectively. Despite the enlarged nozzle plate, the burner temperature dropped to 1200°C, about 30°C lower than before. Although this increases the amount of coal loaded in a single hole, due to the low temperature of the coke oven head, the graphite on the surface of the coke oven door bricks and the bottom of coke oven walls No. 1 and 2 increases, making cleaning more difficult. The surface temperature of the coke oven door is low, and tar seeps out from the door mesh and bottom in the early stages of coking, and condensate water flows out in winter, affecting the cleanliness of the door surface. At the same time, after the door is removed, due to the low temperature of the coke surface on the machine side, black smoke and flames will emit, which will not only turn the coke oven door and frame black, but also pollute the environment.

1.3 Furnace door alignment operation

Initial alignment must be accurate to prevent improper operation from damaging the tightness of the coke oven door. At the same time, strengthen cleaning management, carefully clean the tar residue, coke powder and other residues on the surface of the coke oven door sealing edge, coke oven door frame and door lining bricks, especially the tar in the sealing edge groove and door corners, to ensure that the sealing edge and door frame Normal contact and self-sealing. In addition, coal should be loaded fully, flatly and firmly, and it is strictly forbidden to have missing corners on both sides of the machine’s coke, which will cause the coke oven head to heat up and damage the coke oven door.

1.4 Coke oven door repair

Carry out regular maintenance on coke oven doors to improve the quality of door maintenance. Coke oven doors that are smoking or damaged should be repaired promptly. Coke oven doors should be inspected regularly, preferably every three months. After inspection, all parts of the door must be intact, the frame bolts and springs must remain flexible, and the sealing edges must be flat and adjustable. At the same time, check the integrity of the coke oven door lining bricks. If the damage is serious, it will cause the coke oven door to be deformed due to high local temperature, damage the tightness of the door, and cause the burner coke to collapse when the door is removed. Therefore, it should be replaced in time.

coke oven plant

2. Measures to reduce smoke from coke oven doors

2.1 Improve the sealing performance of the furnace door

By studying the structure and materials of the coke oven door, the thickness of the mesh plate was increased from the original 1.5mm to 2mm. The butt welds at the four corners of the stencil are changed to internal and external edge welding to form an overall right angle. The wall thickness at the four corners is doubled, and the welds are changed from right angles to flat surfaces, which solves the problems of insufficient strength and edge damage caused by the previous butt welding process, as well as the four-corner welding. Frequent cracking of seams. The strength and toughness of the stencil have been greatly improved, and the smoke phenomenon has been effectively controlled, which reduces the labor intensity of employees, improves the working environment, and extends the service life of the coke oven door sealing edge.

2.2 Improve operation level

Improve the operating level of the operators, operate carefully, and ensure that the coal loading car and coke car are aligned at one time to prevent damage to the sealing edge of the coke oven door due to improper operation and affect the tightness of the oven door. At the same time, strengthen cleaning management. When disassembling the coke oven door, immediately clean the tar residue, coke powder and other residues on the coke oven door sealing edge, door frame and door lining brick surface, especially the tar in the sealing edge groove and door corners, to prevent the sealing edge from losing its self-sealing Effect.

Ensure that the sealing edge of the coke oven door is in normal contact with the door frame and is self-sealing. In addition, coal should be loaded fully, flatly and firmly, and it is strictly forbidden to have missing corners on both sides of the machine’s coke, which will cause the coke oven head to heat up and damage the coke oven door.

2.3 Strengthen maintenance and management

Strengthen the maintenance and management of coke oven doors, improve the quality of door maintenance, and promptly repair damaged coke oven doors. Coke oven doors should be inspected regularly, once every three months. After inspection, all parts of the coke oven door must be intact, the frame bolts and iron cross bolts must be flexible, and the sealing edge must be flat and adjustable. After installing and using the overhauled coke oven door, the sealing tightness of the sealing edge must be followed up and checked.

2.4 Check the integrity of the furnace door lining bricks

Check the integrity of the coke oven door lining bricks. If the damage is serious, it will cause the local temperature of the door to be too high and deform, damaging the tightness of the door. At the same time, when the door is removed, the burner coke collapses, increasing the risk of the head and tail of the coke oven, so it should be replaced in time.

2.5 Add furnace door insulation layer

Increase the insulation layer of the coke oven door to further increase the temperature of the coke oven head, ensure the temperature of the coke oven shoulder and head bricks, and reduce the degree of brick erosion.

The furnace door used in coking plants is a vital piece of equipment in coking production, and its sealing performance directly affects production efficiency and environmental protection indicators. By optimizing the furnace door structure, improving operation levels, and strengthening maintenance management, we can effectively reduce furnace door smoke, protect the environment, and improve production efficiency. I hope this article can provide some useful reference for coking plant staff and help achieve green and environmentally friendly production goals.

Coking Equipment Manufacturer
coke ovens
coke oven door

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