Method for preventing the upward pipe cover from being broken off during the charging operation of coke oven

Abstract

The application discloses a method for preventing the updraft pipe cover from being washed away during the charging operation of a coke oven, which comprises the following five aspects: 1. pressure maintaining of the updraft pipe water seal cover cylinder before the charging operation starts and before the charging operation of the next oven; 2. changing the starting sequence and the screw speed adjustment of the first to 5# screw feeders; 3. changing the matching surface between the lower edge of the coal charging sleeve of each charging vehicle and the oven ring of the coal charging port; 4. adjusting the spraying mode of the high-pressure ammonia water nozzle on the bridge pipe; and 5. adjusting the water seal water level of the updraft pipe water seal seat. The application realizes the smokeless exhaust of the 6-meter top-charging coke oven charging vehicle during the charging operation, the smokeless and fireless coal charging port, and the updraft pipe cover not being washed away to cause the raw coal gas overflow.

Description

Technical Field

[0001] This invention relates to coal charging operation technology for coke oven charging cars, and more specifically, to a method for preventing the riser pipe cover from being blown open during coke oven coal charging operations. Background Technology

[0002] The coal charging car is one of the four main types of cars used in coke ovens. Its primary function is to receive coal from the coal tower into the coal hopper on the charging car. The charging car then travels according to the planned coal oven number, using a cover remover, coal feeding sleeve, and screw feeder to load the coal from the hopper into the corresponding carbonization chamber for dry distillation. The smokeless coal charging system changes the previous extensive charging method of top-charging coke ovens. Through the close integration of the coal charging sleeve with the carbonization chamber's coal feeding port ring, the optimization of the 1# to 5# coal feeding operation methods during charging, and the implementation of coke oven riser cover pressure maintenance technologies, the system achieves smokeless coal charging operation.

[0003] After the coal loading tower is full, the coal loading car travels to the corresponding carbonization chamber. Through five coal hoppers on the car and disc feeders at the bottom of the hoppers, coal is evenly loaded into the air-isolated coke oven carbonization chamber through five feeding ports. Simultaneously with the coal loading via the five disc feeders, due to the high temperature of 1000℃ inside the carbonization chamber, a large amount of combustible gases, such as raw coal gas and soot, escapes from the feeding ports. 30-40% of this is drawn into the gas collection pipe by high-pressure ammonia water installed on the bridge pipe for chemical treatment, while 60-70% is purified by a ground dust collection device to achieve smokeless coal loading and protect the production environment. However, in actual production operations, fluctuations in suction caused by the aging of the coal loading dust removal fan and malfunctions of the high-pressure ammonia water pump result in severe flue gas emissions during the coal loading process, posing a significant environmental safety risk.

[0004] The existing coke oven coal charging cars have been modified into fully enclosed coal charging cars, equipped with a remote control system for the riser pipe. This fully enclosed coal charging process eliminates the need for ground coal charging and dust removal. The coal charging capacity of a single hole in a 6-meter coke oven carbonization chamber is about 31 tons. Wet coal with a moisture content of about 12% must be quickly charged into the carbonization chamber within 2 minutes. The charged pulverized coal quickly comes into contact with the high-temperature carbonization chamber wall, which is above 1200°C, and instantly generates a large amount of raw coal gas. All of this gas is drawn into the gas collection pipe and sent to the chemical industry through the negative pressure generated by the high-pressure ammonia water injection.

[0005] After the coal loading car system was put into operation, the dust removal during coal loading was eliminated. All the flue gas generated during the coal loading process was sucked into the gas collection pipe through the negative pressure generated by the high-pressure ammonia water nozzles installed on the bridge pipe. However, the coal loading car often experienced environmentally damaging incidents such as the riser cover being blown open and the coal gas escaping, and black smoke coming out of the coal feeding port. Extending the coal loading time and loading less coal did not significantly improve the situation, seriously affecting clean and efficient production. Summary of the Invention

[0006] In view of the above-mentioned defects in the existing technology, the purpose of the present invention is to provide a method to prevent the riser cover from being blown open during coal charging operations, so as to achieve no smoke exhaust, no smoke or fire at the coal feeding port, and no leakage of raw coal gas caused by the riser cover being blown open during the coal charging operation of the 6-meter top-loading coke oven coal charging car.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preventing the riser pipe cover from being blown open during coke oven coal charging operations includes the following five aspects:

[0009] 1. Maintain pressure in the riser pipe water seal cylinder from the start of coal charging operation to the start of the next coal charging operation;

[0010] 2. Modify the starting sequence of the first to fifth screw feeders and adjust the speed of the feeding screw;

[0011] 3. Change the mating surface between the coal feeding sleeve and the furnace ring at the coal feeding port of each of the first to fifth coal loading cars;

[0012] IV. Adjust the spray pattern of the high-pressure ammonia nozzles on the bridge pipe;

[0013] 5. Adjust the water seal height inside the water seal seat of the riser pipe.

[0014] Preferably, the first aspect further includes:

[0015] When the coke oven central control receives signals that the riser pipe cover is closed, the bridge pipe flap opening exceeds 75%, and the ammonia water nozzle is switched to high pressure, it short-circuits the normally closed contact of the relay in the riser pipe water seal cover cylinder, so that the coil of the solenoid valve in the closed position is continuously energized. The coke oven central control continuously maintains the signal output of the riser pipe water seal cover being closed, the solenoid valve will not leak air, the riser pipe water seal cover is closed, and the cylinder continues to have pressure.

[0016] Before the next furnace is charged with coal, the ammonia water nozzle of this furnace is switched to low pressure, the coke oven central control stops the signal output of the riser pipe water seal cover closing, the coils on both sides of the solenoid valve are de-energized, thus achieving pressure relief, and the compressed air in the riser pipe water seal cover cylinder is discharged through the solenoid valve.

[0017] Preferably, the second aspect further includes:

[0018] The first to fifth screw feeders are started in the order of fifth-third-first-fourth-second, with each screw feeder starting at a 2-second interval.

[0019] During the coal loading process, the feeding screw speed is adjusted. When the coal loading reaches 30%, the screw feeding speed of the first to fifth screw feeders at each coal feeding port is adjusted. When the coal loading reaches 85%, a coal leveling command is issued to keep the deviation of the remaining coal in the five coal hoppers within 0.5t when the coal leveling command is issued. After the coal leveling is completed, coal loading at each coal feeding port stops simultaneously.

[0020] Preferably, the third aspect further includes:

[0021] The lower edge of the coal unloading sleeve of the coal loading car is machined into an arc curve;

[0022] The edge of the furnace ring at the coal feeding port is machined into a tapered line that matches the arc curve.

[0023] Preferably, the fourth aspect further includes:

[0024] Replace the ammonia nozzle with an arc-shaped atomizing nozzle.

[0025] Preferably, the fifth aspect further includes:

[0026] Each of the coal loading cars is equipped with a pressure detection device at the coal unloading sleeve position. When both of the first two pressure detection devices measure that the pressure in the carbonization chamber is below -300Pa, the coal loading operation begins.

[0027] Adjust the water seal level of the riser pipe to 160mm.

[0028] This invention provides a method to prevent the riser pipe cover from opening during coke oven coal charging operations. This method utilizes a negative pressure suction generated by high-pressure ammonia water while maintaining positive pressure in the coke oven gas collecting pipe, preventing the riser pipe cover from opening during fully enclosed coal charging operations. Through close contact between the coal guide sleeve of the charging car and the furnace ring at the coal feeding port, and precise control of coal leveling, no flue gas escapes during the charging process. This significantly improves the environmental appearance of the furnace top area, maintaining clean production under high-load production conditions and generating substantial economic and social benefits. Simultaneously, the labor intensity of coke oven top operators and coal charging car operators is reduced. This achieves green steelmaking and harmonious development between the city and the steel plant environment. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the riser tube and bridge tube in the method of the present invention;

[0030] Figure 2 This is a schematic diagram of the mating surface between the lower edge of the coal feeding sleeve and the furnace ring of the coal feeding port in the method of the present invention. Detailed Implementation

[0031] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] Combination Figure 1 As shown, the present invention provides a method for preventing the riser pipe cover from being blown open during coke oven coal charging operations, comprising the following five aspects:

[0033] 1. Maintain pressure in the riser pipe water seal cylinder 1 from the start of coal charging operation to the start of the next coal charging operation;

[0034] 2. Modify the starting sequence of the first to fifth screw feeders and adjust the speed of the feeding screw;

[0035] 3. Change the mating surface between the lower edge 9 of the coal feeding sleeve 8 and the furnace ring 11 of the coal feeding port 10 of each of the first to fifth coal loading cars;

[0036] IV. Adjust the spraying mode of the high-pressure ammonia nozzle 3 on bridge pipe 2;

[0037] 5. Adjust the water seal level in the water seal seat 6 of the riser pipe 4.

[0038] The first aspect mentioned above further includes:

[0039] By modifying the wiring inside the riser gas control cabinet 5, when the coke oven central control in the riser gas control cabinet 5 receives signals that the opening degree of the riser cover 7 and the bridge pipe flap exceeds 75% and the high-pressure ammonia water nozzle 3 switches to high pressure, the normally closed contact of the relay in the riser water seal cover cylinder 1 is short-circuited, so that the coil of the solenoid valve in the closed position is continuously energized. The coke oven central control continuously maintains the closing signal output of the riser water seal cover cylinder 1, the solenoid valve will not leak air, and the closing action of the riser water seal cover cylinder 1 will continue to have pressure.

[0040] Before the next furnace is charged with coal, the high-pressure ammonia water nozzle 3 of this furnace is switched to low pressure. The coke oven central control stops the closing signal output of the riser pipe water seal cover cylinder 1. The coils on both sides of the solenoid valve are not energized, thus releasing pressure. The compressed air in the riser pipe water seal cover cylinder 1 is discharged through the solenoid valve, thus maintaining the pressure of the riser pipe cover 7 and ensuring that the riser pipe cover 7 is not blown open during coal charging.

[0041] To ensure safety during coke oven venting, the initial design considered that after the riser cover 7 was closed, the solenoid valve of the riser water seal cover cylinder 1 would return to the midpoint after the cylinder was closed, allowing the riser water seal cover cylinder 1 to depressurize and remain in a state where it could always be opened. Experiments showed that maintaining pressure on the two riser covers 7 in each group of 50-hole carbonization chambers to prevent them from opening would not pose a safety hazard even if coke oven venting occurred.

[0042] The second aspect above further includes:

[0043] The first to fifth screw feeders are started in the order of fifth-third-first-fourth-second, with each screw feeder starting at a 2-second interval. The raw coal gas generated at the moment of coal loading can be smoothly introduced into the gas collection pipe located on one side of the carbonization chamber.

[0044] At the same time, after the coal feeding sleeve reaches the "down" position, the oil cylinder is used to pressurize it, so that the coal feeding sleeve and the furnace ring are fully sealed.

[0045] Meanwhile, the feeding screw of the coal loading car directly loads coal at high speed, eliminating the setting of first slow speed for 5 seconds and then switch to high speed. The pressure in the carbonization chamber during the initial coal loading is reduced from 3000Pa to below 800Pa.

[0046] During the coal loading process, the feeding screw speed is adjusted. When the coal loading reaches 30%, the screw feeding speed of the first to fifth screw feeders at each coal feeding port is adjusted. When the coal loading reaches 85%, a leveling command is issued to keep the deviation of the remaining coal in the five coal hoppers within 0.5t when the leveling command is issued. After the leveling is completed, each coal feeding port stops loading at the same time, achieving full loading and leveling. At the same time, the coal loading is completed just as the pusher car reaches the forward end of the leveling, reducing the amount of remaining coal pulled out.

[0047] The original design of the coal loading car involved loading coal in the order of fifth-fourth-third-second-first, with each loading port starting 2 seconds apart. Each port would initially load coal at a low speed for 5 seconds before switching to high speed. This caused a "coal explosion" phenomenon when the initial small amount of pulverized coal came into contact with the high-temperature environment. The pressure in the carbonization chamber would instantly rise to about 3000 Pa, and the highest pressure measured through the riser pipe's drain hole was 7200 Pa. This made it very easy for the riser pipe cover to be blown open, causing a large amount of raw coal gas to escape.

[0048] The third aspect mentioned above further includes:

[0049] Combination Figure 2 As shown, the lower edge 9 of the coal loading sleeve 8 of the coal loading car is processed into an arc curve, and the edge 11 of the furnace ring of the coal feeding port 10 is processed into a conical line that matches the arc curve.

[0050] Thus, the lower edge 9 of the arc-shaped coal feeding sleeve 8 and the edge 11 of the furnace ring of the conical coal feeding port 10 make line contact, achieving a completely tight fit regardless of the docking conditions. Before the coal charging car begins coal feeding, the actual amount of coal loaded into each coal hopper is inconsistent with the amount displayed by the sensor weighing device because the coal feeding sleeve 8 is automatically pressurized during coal loading. Therefore, multiple tests were conducted to obtain the corresponding proportional relationship curve parameters. Then, the coal loading amount of the coal charging car is automatically set according to the moisture content of the loaded coal, and the automatic distribution of coal hoppers 1 to 5 is performed through a program. This ensures that the coal loading amount of the five coal feeding ports is adapted to the coal amount in different parts of the carbonization chamber, allowing the raw coal gas to be smoothly discharged and reducing the pressure in the furnace top space of the carbonization chamber.

[0051] The fourth aspect mentioned above further includes:

[0052] The high-pressure ammonia water nozzle 3 is replaced with an arc-shaped atomizing nozzle instead of the existing columnar spraying method. Without changing the pressure of the existing high-pressure ammonia water, the suction at the riser pipe 4 and bridge pipe 2 is increased by changing the spraying method. The negative pressure generated at the root of the riser pipe 4 is above -460Pa, which ensures the suction of the gas collecting pipe to the raw coal gas in the carbonization chamber during the coal charging operation.

[0053] The fifth aspect mentioned above further includes:

[0054] Since the water seal level in the water seal seat 6 of the riser pipe 4 was originally set to 90mm, it can normally meet the needs of the coal loading process of the coal loading car. However, if there is an abnormal situation such as the blockage of the coal loading sleeve of the coal loading car, and the coal loading car driver does not notice it in time and still continues to automatically add coal, sometimes the water seal of the water seal seat 6 of the riser pipe 4 will break down instantly, and the raw coal gas will come out at the water seal position of the riser pipe cover 7.

[0055] Therefore, on the one hand, pressure detection devices are installed at the coal unloading sleeve position of each coal loading car. When both pressure detection devices measure that the pressure in the carbonization chamber is below -300Pa, the coal loading operation begins and is integrated into the coal loading car operation interlock.

[0056] Meanwhile, to avoid the impact of pressure fluctuations during coal loading, the water seal level of the water seal seat 6 on the riser pipe 4 is adjusted to 160mm to prevent the water seal of the riser pipe from being punctured and causing smoke.

[0057] This invention relates to a method for preventing the riser pipe cover from opening during coke oven coal charging operations. It pertains to a control technology and device for preventing excessively high instantaneous flue gas pressure during coke oven coal charging, primarily used for operational control during the charging process. It is the first fully enclosed 6-meter coke oven coal charging car in China. During coal charging operations, ground-based dust removal is eliminated. All flue gas passes through the riser pipe and bridge pipe. The suction generated by high-pressure ammonia water injection on the bridge pipe draws the flue gas and raw coal gas generated during the charging process into the gas collection pipe and then sends them for chemical treatment. Through multiple experiments, it was found that the coal charging operation is affected by factors such as the sealing of the coal charging car sleeve, charging speed, charging sequence, coal leveling coordination, high-pressure ammonia water injection, and the opening and closing of the riser pipe. Therefore, truly smokeless coal charging must be achieved through equipment function optimization, multi-factor coordination, and key parameter optimization.

[0058] The coking process involves the high-temperature dry distillation of coking coal in the carbonization chamber of a coke oven in the absence of air. This process consumes a large amount of coal gas and produces gases such as COx, NOx, and SO2. The coal charging and coke pushing processes release various organic compounds and particulate matter. Whether clean, efficient, and low-consumption production can be achieved is the key to realizing the urban steel and environmental management philosophy.

[0059] In the coking production process, over time, coke oven damage, gas leaks, yellow smoke, carbon buildup, and the escape of pollutants such as raw coal gas during coal charging and leveling operations frequently occur. Therefore, reducing fugitive emissions from coke ovens is our primary task. Secondly, coke oven operations are mainly based on unit automation, with coordination between operations largely reliant on manual labor. Therefore, automated control technology for coke ovens is crucial. This patent, through equipment improvements, standardized operating procedures, and equipment optimization, achieves zero smoke emissions during coal charging, resulting in an energy-saving, environmentally friendly, clean, and low-consumption coke oven.

[0060] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for preventing the water seal of the uptake pipe from being broken during the charging operation of a coke oven, characterized in that, Comprise the following five aspects: I. In the coal charging operation to the next coal charging operation before the rising pipe water seal cover cylinder pressure, specifically: When the coke oven control receives the rising pipe water seal cover closing, the opening of the bridge pipe flap exceeds 75%, the ammonia water nozzle switches to high pressure signal, the normally closed point of the rising pipe water seal cover cylinder relay is short-circuited, so that the closing position coil of the electromagnetic valve is continuously powered, the signal output of the coke oven control is continuously maintained to close the rising pipe water seal cover cylinder, the electromagnetic valve will not leak, the rising pipe water seal cover is closed, and the cylinder has continuous pressure; When the next furnace is coal charging, the ammonia water nozzle of the present furnace is switched to low pressure, the coke oven control stops the signal output of the rising pipe water seal cover cylinder closing, the coils on both sides of the electromagnetic valve are not powered, the pressure is released, and the compressed air in the rising pipe water seal cover cylinder is discharged through the electromagnetic valve; II. Change the starting order of the first to fifth screw feeders and adjust the screw feeding speed, specifically: The first to fifth screw feeders are started in the order of fifth-third-first-fourth-second, and each screw feeder is started with an interval of 2 seconds; During the coal charging process, the screw feeding speed is adjusted, the screw feeding speed of the first to fifth screw feeders of each coal charging port is adjusted when the coal charging amount reaches 30%, a coal leveling instruction is issued when the coal charging amount reaches 85%, the residual coal amount deviation in the five hoppers is kept within 0.5t when the coal leveling instruction is issued, and the coal charging of each coal charging port is stopped simultaneously after the coal leveling is completed; III. Change the matching surface between the lower edge of the coal charging sleeve of each of the first to fifth coal charging cars and the furnace ring of the coal charging port, specifically: The lower edge of the coal charging sleeve of the coal charging car is processed into an arc curve; The edge of the furnace ring of the coal charging port is processed into a conical line matched with the arc curve; IV. Adjust the spraying mode of the ammonia water nozzle on the bridge pipe, specifically: Replace the ammonia water nozzle with an arc-shaped atomizing nozzle; V. Adjust the water seal water level of the water seal seat on the rising pipe, specifically: Pressure detection devices are installed at the position of the coal charging sleeve of each coal charging car, and when the pressure in the carbonization chamber measured by the two pressure detection devices is below-300Pa, the coal charging operation starts; The water seal water level of the water seal seat on the rising pipe is adjusted to 160mm.

Images