A dry quenching oven method

Abstract

The application discloses a dry quenching coke oven baking method, comprising the following contents: (1) canceling the gas baking, changing to the red coke baking, through controlling the coke loading speed, the coke discharging amount, the circulating air volume, the impact of the red coke on the masonry is reduced to the minimum; (2) increasing the cold coke loading amount before the baking, ensuring that the coke can be normally discharged in the early baking period, and eliminating the risk of suspended material; (3) through the fine adjustment of the circulating air volume, the low-pressure steam volume, the air introduction amount and the opening degree of each diffusion valve, the problem of uneven temperature rise caused by the steam pressure and temperature fluctuation in the warm air drying process is eliminated. After the application is implemented, the baking time of the dry quenching coke is shortened from the original 15 days to 8 days, the gas baking is cancelled, the gas consumption of 9 days is saved, the production time is further shortened, the risk of suspended material in the baking process is eliminated, and the whole process is more stable and smooth.

Description

Technical Field

[0001] This invention relates to a dry quenching coke oven method, belonging to the field of metallurgical coking. Background Technology

[0002] Dry quenching is a method of cooling red-hot coke using inert gas. A dry quenching furnace in a dry quenching system consists of a pre-storage section, an inclined chute zone, and a cooling section. Based on the current operating conditions of dry quenching in major steel enterprises in China, the refractory bricks in the inclined chute zone and pre-storage section suffer from severe breakage, brick loss, and wear. Therefore, major overhauls of the inclined chute, primary dust removal system, pre-storage section, and furnace mouth are necessary every two to four years.

[0003] After the annual overhaul of the dry quenching system involves the reconstruction of a large area of ​​refractory material, a furnace drying operation must be carried out. This involves gradually heating the dry quenching system from a cold state to a temperature suitable for loading red-hot coke. The success of the furnace drying operation, the effectiveness of moisture removal from the refractory masonry within the quenching furnace, the control of thermal expansion of the refractory masonry, and the stability of the furnace temperature rise all significantly impact the stable operation of the dry quenching unit.

[0004] The dry quenching coke oven drying process is divided into two stages: a warm air drying stage, primarily aimed at removing moisture from the refractory brickwork of the dry quenching oven and primary dust collector; and a gas-fired oven drying stage, primarily aimed at raising the temperature. During the warm air drying stage, the inlet temperature T2 of the dry quenching oven is the primary management temperature, planned to be raised from ambient temperature to 150-170℃ and maintained (at which point T5 is approximately 120℃). The temperature increase is 10℃ / h. During the gas-fired oven drying stage, the pre-storage chamber temperature T5 of the dry quenching oven is the primary management temperature, planned to be raised from approximately 120℃ to 800℃ and maintained for one day, with a temperature increase of 90℃ / day. Warm air drying takes 5-6 days, and gas-fired oven drying takes 9 days, for a total duration of 14-15 days.

[0005] Traditional oven drying methods have the following drawbacks:

[0006] 1. Traditional oven drying methods are time-consuming, and the energy-consuming medium must meet certain requirements. Specifically, the low-pressure steam consumed in warm air drying should be superheated steam with a pressure above 0.8 MPa and a temperature above 190℃. The coke oven gas consumed in gas-fired ovens should have a calorific value of 16.5 MJ / m3 and a pressure above 3000 Pa, but in reality, it is often far below these levels.

[0007] 2. Using coke oven gas to heat the furnace can raise the top temperature of the dry quenching furnace to 800℃. However, after the furnace heating operation is completed, burner removal, sealing of the furnace heating manhole, and nitrogen purging are required. These operations take at least 4 hours to complete. During this time, the top temperature T5 of the dry quenching furnace drops from 800℃ to about 560℃. At this point, the furnace top temperature differs from the temperature of the hot coke (1050℃) that will be loaded into the dry quenching furnace by as much as 500℃, and the main purpose of the gas-heated furnace heating will not be achieved.

[0008] 3. Before installing the gas burner, the dry quenching furnace needs to be loaded with approximately 40 tons of coke. A layer of coke dipped in refractory slurry is then laid on top of the coke as a pressing layer (insulation layer). This avoids the risk of the coke igniting due to increased temperature during furnace drying and also prevents coke powder and small coke particles from being blown away. However, because the moisture in the slurry seeps through the coke layer and accumulates at the bottom of the dry quenching furnace, the coke inside the furnace eventually caking, forming suspended material that prevents the coke from being discharged. Summary of the Invention

[0009] This invention aims to provide a highly efficient dry quenching coke oven drying method that improves the cold coke loading level before drying, eliminates the need for a heat insulation layer on top of the cold coke, optimizes and improves the adjustment methods during warm air drying, and replaces the gas oven with a red coke oven, ultimately achieving the goals of shortening the drying time, saving energy, and eliminating the risk of suspended material.

[0010] This invention analyzes the shortcomings of the original furnace drying plan and the current status of refractory materials, equipment, and processes in dry quenching furnaces. Starting with warm air drying, it eliminates the influence of steam pressure and fluctuations through fine-tuning various parameters. It replaces the gas-fired furnace with a red-coke-fired furnace, controlling the charging rate, coke discharge rate, and circulating air volume to regulate the temperature rise of the furnace system, achieving rapid furnace drying. This invention significantly shortens the heating time of the dry quenching furnace, reducing the complete dry quenching process from 15 days to 8 days, and improving the dry quenching rate.

[0011] The technical concept of this invention is as follows: ① In the warm air drying stage, the insufficient steam pressure or temperature is compensated for by improving the operation method. The main purpose of the gas-fired oven is to heat the refractory bricks in the dry quenching furnace to bring their temperature close to that of the hot coke, so as to facilitate the transition to normal production. In the early stages of dry quenching, the refractory bricks used had poor thermal shock resistance. Type B mullite silicon carbide bricks were used in the inclined section. If the hot coke was directly loaded, the huge temperature difference would cause irreversible damage to the masonry. The design structure of the inclined section of modern large-scale dry quenching furnaces has been modified to rationally distribute the supporting bearing pressure. The opening area of ​​the annular flue has been increased to 1.5 times the original size, and the number of flue brackets has been reduced from 36 to 32 to ensure that the bearing area of ​​the brackets is effectively increased and the bearing capacity is increased. In addition, the inclination angle of the supporting brackets has been reduced from the original 70° to 63-65° to increase the bearing capacity at the root; and the grooveless whole bricks have been replaced with single-layer bricks with grooves to increase the interlocking force. The above improvements are all aimed at enhancing the resistance of the refractory bricks in the inclined section to thermal expansion and erosion. Furthermore, the bricks used for the inclined section have been changed from type B mullite to mullite-andalusite refractory bricks, which have better resistance to rapid heating and cooling and higher flexural strength, resulting in thermal shock stability exceeding 50 cycles. Therefore, direct contact with red-hot coke will not damage the refractory bricks in the inclined section. If the amount of red-hot coke charged is strictly controlled and the circulating gas flow is increased to quickly remove the heat from the coke, the risk will be minimized. Moreover, since red-hot coke has a relatively high sensible heat, it can be used directly instead of coal gas as a heat source to heat the furnace body and raise the temperature of the refractory bricks. ② Increasing the amount of cold coke charged in the early stages ensures continuous and uninterrupted coke discharge during the red-hot coke baking process, keeping the coke in constant motion within the furnace and eliminating the problem of coke hanging due to stagnation and large temperature differences, thus preventing unnecessary trouble during production.

[0012] The innovative aspects of this invention are as follows:

[0013] 1. Replace the gas-fired oven with a red coke oven. By controlling the coke loading speed, coke discharge volume, and circulating air volume, the impact of red coke on the masonry can be minimized.

[0014] 2. Increase the amount of cold coke charged before the oven is dried (140-160 tons) to ensure that coke can be discharged normally in the early stage of oven drying and eliminate the risk of suspended material.

[0015] 3. By fine-tuning the circulating air volume, low-pressure steam volume, air introduction volume, and the opening degree of each vent valve, the problem of uneven heating caused by steam pressure and temperature fluctuations during the warm air drying process is eliminated.

[0016] In this invention, temperature T2 is the inlet temperature of the dry quenching furnace, temperature T5 is the pre-storage chamber temperature, temperature T6 is the boiler inlet temperature, and temperature T7 is the boiler outlet temperature.

[0017] This invention provides a method for dry quenching coke ovens, comprising the following:

[0018] Step 1, Preparation: Use a long-arm excavator (or a 25-ton crane and loader) to load the prepared cold coke into the auxiliary tank of the coke car. Utilize the interval between loading and unloading to transfer the coke into the dry quenching furnace. When loading cold coke, control the loading time by adding one tank of coke into the dry quenching furnace within 15 minutes. Stop loading cold coke when the radar level gauge shows a level of 4 meters. Prepare an adjusting plate (with a wooden board as a spare) at the emergency vent valve to adjust the opening of the emergency vent, thereby controlling the amount of air entering the dry quenching furnace.

[0019] Step 2: Adjust the status of each valve in the dry quenching furnace system:

[0020] (1) Emergency vent valve: equipped with an air inlet regulating plate;

[0021] (2) Dry quenching furnace inlet damper: Open;

[0022] (3) Circulating fan inlet flap: Open;

[0023] (4) Air inlet valve: Closed;

[0024] (5) 1DC and 2DC type valves: Stop operation;

[0025] (6) All water outlets in the cooling chamber of the dry quenching furnace: Open;

[0026] (7) Maintenance flat gate: Open;

[0027] (8) Pre-storage chamber pressure regulating valve: Closed;

[0028] (9) Quick-cut valve: Closed;

[0029] (10) Gas analyzer sampling tube: Closed;

[0030] Step 3: Close all manhole doors of the dry quenching furnace system, including (1) all manhole doors on the boiler; (2) all manhole doors on the circulating gas system; (3) all manhole doors of the primary and secondary dust collectors; (4) all manhole doors on the dry quenching furnace; and (5) all manhole doors of the discharge device.

[0031] Step 4: Warm air drying

[0032] (1) First, bypass the water circuit of the low-pressure economizer and use the deaerator circulation pump to heat up the deaerator; during the deaerator heating process, start the boiler water supply and gradually replace the room temperature water in the boiler, and send in low-pressure steam for heating. When the steam drum pressure reaches 0.6MPa, introduce steam into the steam drum.

[0033] (2) Adjust the valve opening according to the heating requirements: when the T6 temperature (boiler inlet temperature) rises to 150℃, turn on the circulating fan; control the air volume at the minimum (fan speed is 3% of the rated speed, air volume is 10000m³ / h). 3 / h), the circulating air volume is adjusted by adjusting the fan speed;

[0034] (3) After the circulating fan is started, the emergency vent valve is opened to start warm air drying. At this time, the temperature of the dry quenching furnace is low and the temperature of the boiler inlet is high. In order to control the heating rate to 5℃ / h, the following measures can be taken: ① Control the circulating fan to run at a low speed of about 5%; ② Open all emergency vent valves.

[0035] (4) During the warm air drying process, the inlet temperature T2 of the quenching furnace should be the main management temperature, and the operation should be strictly carried out according to the heating curve of the quenching furnace; the heating rate should be 5±1℃ / h, and maintained after reaching 140±5℃. The deviation between the actual temperature and the planned temperature during the warm air drying process should be controlled within ±10℃, and the temperature of the pre-storage chamber should be controlled above 120℃.

[0036] (5) As the temperature T2 increases, the heating rate gradually decreases. At this time, the heating rate can be controlled by adjusting the speed of the circulating fan and the opening of the emergency vent valve: if the heating rate is fast, the speed of the circulating fan can be reduced or the opening of the emergency vent valve can be increased; if the heating rate is slow, the speed of the circulating fan can be increased or the opening of the emergency vent valve can be decreased.

[0037] (6) Other adjustment methods that may be used to control a reasonable temperature include:

[0038] ①When the T5 temperature rises too quickly, measures can be taken to reduce the amount of low-pressure steam blown in, increase the amount of circulating air, increase the amount of introduced air, and increase the opening of the furnace cover;

[0039] ②When the temperature rises slowly at T5, the amount of low-pressure steam introduced can be increased to reduce the amount of air introduced.

[0040] ③ When the boiler water temperature rises but the circulating gas temperature does not rise, the amount of air introduced can be reduced.

[0041] ④ When the T5 temperature and the circulating gas temperature rise too quickly, the opening of the furnace top cover can be increased to increase the amount of air released and the amount of air introduced.

[0042] ⑤ When the temperature difference between T2 and T5 increases, if the temperature of the circulating gas is greater than that of T5, the circulating air volume should be increased.

[0043] ⑥ When the pressure of P1 (circulating fan outlet pressure) is lower than the benchmark, the circulating air volume can be increased. If the effect is not significant, the furnace top vent valve can be closed or the furnace cover opening can be reduced.

[0044] (7) During the warm air drying period, water discharge operations should be carried out at each water discharge point (1DC discharge section, 2DC discharge section, rotary sealing valve, etc.), and manual drainage should be carried out once per shift.

[0045] (8) When no white steam comes out when the furnace cover is opened, the temperature of T2 is above 140℃, and the warm air drying is over.

[0046] Step 5, Nitrogen replacement:

[0047] After the warm air drying is completed, adjust the circulating fan speed to 300 r / min, close the furnace cover, close the emergency vent valve, keep the pre-storage chamber pressure regulating valve and quick-cut valve closed, and keep the pre-storage chamber vent valve open, controlling the pre-storage chamber pressure to 0-50 Pa. Open the main nitrogen valve (fully open), and fully open the nitrogen bypass valve before or after the fan, controlling the nitrogen flow rate to 3000 m³ / min. 3 Once the flow rate exceeds a certain threshold, nitrogen purging begins.

[0048] During the replacement process, monitor the change in oxygen content in the gas analyzer. After about 1.5 hours, the gas analyzer will show an oxygen content of <5%. At this time, use a portable alarm to measure the O2 content of the vent gas at the vent valve of the pre-storage chamber. When the oxygen content is confirmed to be <5%, the nitrogen replacement is considered to be completed, and the red coke heating operation can be carried out.

[0049] Step 6: Heat the red coke.

[0050] (1) After the warm air drying is completed, start the coke discharge operation. Control the coke discharge rate to 60t / h for coke discharge test. Stop the coke discharge when the material level is 3 meters and prepare for the red coke loading operation.

[0051] (2) When loading red coke, the main management temperature is T5, and the heating rate is controlled at about 10℃ / h. The auxiliary management temperature is T6, and the heating rate is controlled at about 10℃ / h.

[0052] (3) Before loading coke, gradually adjust the speed of the circulating fan to 450 r / min and prepare to load red coke and heat it up.

[0053] (4) In order to prevent the large temperature difference between the hot coke and the cold coke after the hot coke is loaded, which would cause the thermal stress of the surface cold coke to increase sharply and form a shed phenomenon in the dry quenching furnace, which would affect the uniformity of coke discharge in the later stage and even cause material suspension, the vibration feeder amplitude is adjusted to 5Hz 15 minutes before the first batch of hot coke is loaded, and the coke discharge rate is about 20t / h to ensure that the cold coke in the lower part is always in a flowing state during the loading of hot coke.

[0054] (5) When the dry quenching furnace is loaded with red coke, the material level is low. In order to ensure that the system pressure does not fluctuate greatly, the coke must be loaded in a flowing manner. At this time, the elevator needs to be switched to manual operation, and the coke is controlled to flow into the dry quenching furnace intermittently over 15-20 minutes.

[0055] (6) To prevent large fluctuations in the pressure of the pre-storage chamber during coke loading, the pre-storage chamber vent valve is opened, and the desulfurization valve is manually operated to adjust the negative pressure during coke loading.

[0056] (7) To avoid a significant increase in T5 temperature, after loading the red coke, gradually adjust the speed of the circulating fan to 600 r / min;

[0057] (8) During the process of heating and pressurizing the boiler drum, pay attention to the management of drainage and blowdown of various parts of the boiler. When the main steam temperature of the boiler reaches 420℃, start the desuperheating water regulating valve.

[0058] (9) After loading the red coke, the temperatures at points T5 and T6 will continue to rise and then begin to fall. At this time, the speed of the circulating fan should be gradually reduced to 300±30 r / min according to the actual situation. This is to avoid the O2 content of the circulating gas exceeding 5% and to avoid the temperature difference between T5 and T6 being too large, which would affect the temperature rise.

[0059] (10) When the temperatures of T5 and T6 drop to meet the heating requirement of 10±1℃ / h, the second batch of red coke can be prepared for loading.

[0060] (11) 0.5 hours after the second batch of red coke is loaded, adjust the amplitude of the vibrating feeder to 10±2Hz.

[0061] (12) When the material level in the dry quenching furnace is 10-11 meters, the heating rate is mainly controlled by adjusting the speed of the circulating fan and the frequency of red coke loading; when the material level is above 11 meters, it can be controlled by the amount of coke discharged and the amount of circulating air.

[0062] (13) When the boiler inlet temperature is ≥650℃, stop the nitrogen supply to the system and open the middle valve and air inlet valve to introduce air into the system to reduce the concentration of combustible components such as H2 and CO in the circulating gas.

[0063] (14) When the T6 temperature is ≥960℃, the red coke heating ends and normal production can begin.

[0064] The beneficial effects of this invention are:

[0065] After implementing this invention, the oven drying time for dry quenching coke is shortened from 15 days to 8 days, increasing coke production by 7 days; eliminating gas-fired oven drying saves 9 days' worth of gas consumption; reducing subsequent burner removal and manhole sealing operations further shortens the commissioning time; and eliminating the risk of material suspension during oven drying, making the entire process more stable and smooth. Based on an additional 10 ovens per day, with each oven producing 45 tons, completing oven drying 7 days earlier results in approximately 10 × 45 × 7 = 3150 tons of additional dry quenched coke. Detailed Implementation

[0066] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments. Example

[0067] A method for dry quenching coke ovens, the specific scheme of which is as follows:

[0068] 1. Preparation

[0069] Use a long-arm excavator (or a 25-ton crane and loader) to load the prepared cold coke into the auxiliary tank of the coke tanker. Use the gap between the furnace discharges to load it into the dry quenching furnace of the furnace to be dried. When loading cold coke, control the loading of one tank of coke into the dry quenching furnace within 15 minutes. Stop loading cold coke when the coke level reaches 4 meters as shown by the radar level gauge.

[0070] The amount of cold coke loaded in this invention is increased compared to the original technology: originally about 100 tons of cold coke were loaded, now it is 140-160 tons of cold coke.

[0071] 2. Status of valves in the dry quenching furnace system:

[0072] (1) Emergency vent valve: Prepare an air inlet regulating plate (wooden board for backup) at the emergency vent valve in advance to adjust the opening of the emergency vent, thereby controlling the amount of air entering the dry quenching furnace;

[0073] (2) Dry quenching furnace inlet damper: Open

[0074] (3) Circulating fan inlet flap: Open

[0075] (4) Air inlet valve: Closed

[0076] (5) 1DC and 2DC type valves: Stop operation

[0077] (6) Water discharge points in the cooling chamber of the dry quenching furnace: Open

[0078] (7) Maintenance flat gate: Open

[0079] (8) Pre-storage chamber pressure regulating valve: Closed

[0080] (9) Quick-cut valve: Close

[0081] (10) Gas analyzer sampling tube: Close

[0082] Close all manhole doors of the dry quenching furnace system:

[0083] (1) Manholes on the boiler;

[0084] (2) Manholes on the circulating gas system;

[0085] (3) Manhole doors of the primary and secondary dust collectors;

[0086] (4) All manholes on the dry extinguishing furnace;

[0087] (5) Manhole doors of the discharge device.

[0088] 3. Warm air drying

[0089] 3.1 First, bypass the low-pressure economizer water circuit and use the deaerator circulating pump to heat the deaerator. During the deaerator heating process, start filling the boiler with water, gradually replacing the ambient temperature water in the boiler, and introduce low-pressure steam for heating. When the steam drum pressure reaches 0.6 MPa, introduce steam into the steam drum. Adjust the valve opening according to the heating requirements;

[0090] 3.2 When the temperature of T6 rises to 150℃, turn on the circulating fan. Control the airflow at the minimum (fan speed 3% of rated speed, airflow 10000m³ / h). 3 / h), the circulating air volume is adjusted by adjusting the fan speed;

[0091] 3.3 After the circulating fan starts, the emergency vent valve is opened to begin warm air drying. At this time, the dry quenching furnace temperature is low, and the boiler inlet temperature is high. To control the heating rate to 5℃ / h, the following measures can be taken:

[0092] (1) The circulating fan is controlled to run at a low speed of about 5%;

[0093] (2) All emergency vents are opened;

[0094] 3.4 During the warm air drying process, the inlet temperature of the quenching furnace should be the primary control temperature, and operation should be strictly carried out according to the furnace's heating curve. The heating rate should be 5℃ / h, and maintained after reaching 140℃. The deviation between the actual temperature and the planned temperature during the warm air drying process should be controlled within ±10℃, while the temperature of the pre-storage chamber should be controlled above 120℃.

[0095] 3.5 As the temperature T2 increases, the heating rate gradually decreases. At this time, the heating rate can be controlled by adjusting the speed of the circulating fan and the opening of the emergency vent valve: if the heating rate is fast, the speed of the circulating fan can be reduced or the opening of the emergency vent valve can be increased; if the heating rate is slow, the speed of the circulating fan can be increased or the opening of the emergency vent valve can be decreased.

[0096] 3.6 Strict temperature control is required; other adjustment methods may be used when necessary.

[0097] (1) When the T5 temperature rises too quickly, measures can be taken to reduce the amount of low-pressure steam blow-in, increase the amount of circulating air, increase the amount of introduced air, and increase the opening of the furnace cover.

[0098] (2) When the temperature rises slowly at T5, the amount of low-pressure steam blown in can be increased to reduce the amount of air introduced.

[0099] (3) When the boiler water temperature rises but the circulating gas temperature does not rise, the amount of air introduced can be reduced.

[0100] (4) When the T5 temperature and the circulating gas temperature rise too quickly, the opening of the furnace top cover can be increased to increase the amount of air released and the amount of air introduced.

[0101] (5) When the temperature difference between T2 and T5 increases, if the temperature of the circulating gas is greater than that of T5, the circulating air volume should be increased.

[0102] (6) When the outlet pressure P1 (0~50Pa) of the circulating fan is lower than the benchmark, the circulating air volume can be increased. If the effect is not significant, the furnace top vent valve can be closed or the furnace cover opening can be reduced.

[0103] 3.7 During the warm air drying period, water discharge operations should be carried out at each discharge point (1DC discharge section, 2DC discharge section, rotary sealing valve, etc.), and manual drainage should be performed once per shift.

[0104] 3.8 When no white steam comes out when the furnace cover is opened, and the T2 temperature is above 140℃, the warm air drying is over.

[0105] 4. Nitrogen replacement:

[0106] After the warm air drying process is complete, adjust the circulating fan speed to 15% (South Zone, this represents the control parameter for the dry quenching furnace in the South Zone) and 300 r / min (North Zone, this represents the control parameter for the dry quenching furnace in the North Zone). Close the furnace cover and the emergency vent. Keep the pre-storage chamber pressure regulating valve and quick-cut valve closed, and keep the pre-storage chamber vent open, controlling the pre-storage chamber pressure at 0-50 Pa. Open the main nitrogen valve (fully open), and fully open the nitrogen bypass valve before or after the fan, controlling the nitrogen flow rate to 3000 m³ / min. 3 Once the flow rate exceeds a certain threshold, nitrogen purging begins.

[0107] During the replacement process, monitor the change in oxygen content in the gas analyzer. After about 1.5 hours, the gas analyzer will show an oxygen content of <5%. At this time, use a portable alarm to measure the O2 content of the vent gas at the vent valve of the pre-storage chamber. When the oxygen content is confirmed to be <5%, the nitrogen replacement is considered to be completed, and the red coke heating operation can be carried out.

[0108] Regarding the adjustment of the circulating fan speed, the speed measurement ratio used is different because the commissioning time of the South Zone and the North Zone (divided according to the specific application area of ​​Taiyuan Iron & Steel Group) is different. The 15% mentioned above refers to the percentage of the rated value, and the same applies below.

[0109] 5. Heat the red caramel.

[0110] 5.1 After the warm air drying is completed, start the coke discharge operation. Control the coke discharge rate to 60t / h for coke discharge test. Stop the coke discharge when the material level reaches 3 meters and prepare for the loading of red coke.

[0111] 5.2 When heating the red coke, use T5 as the main management temperature and control the heating rate at about 10℃ / h. Use T6 as the auxiliary management temperature and control the heating rate at about 10℃ / h.

[0112] 5.3 Before loading coke, gradually adjust the speed of the circulating fan to 30% (South Zone) or 450 r / min to prepare for loading red coke and raising the temperature;

[0113] 5.4 In order to prevent the large temperature difference between the hot coke and the cold coke after the hot coke is loaded, which would cause a sharp increase in the thermal stress of the surface cold coke and form a bridging phenomenon in the dry quenching furnace, affecting the uniformity of coke discharge later and even causing material suspension, the vibration feeder amplitude is adjusted to 5Hz 15 minutes before the first batch of hot coke is loaded, and the coke discharge rate is about 20t / h to ensure that the cold coke at the bottom is always in a flowing state during the loading of hot coke.

[0114] 5.5 When the red coke is started to be loaded, the material level in the dry quenching furnace is low. In order to ensure that the system pressure does not fluctuate greatly, the coke must be loaded in a flowing manner. At this time, the elevator needs to be switched to manual operation, and the red coke is controlled to flow into the dry quenching furnace intermittently every 15-20 minutes.

[0115] 5.6 To prevent large fluctuations in the pressure of the pre-storage chamber during coke loading, the pre-storage chamber vent valve is opened, and the desulfurization valve is put into central manual operation for coke loading and negative pressure adjustment.

[0116] 5.7 To avoid a significant rise in T5 temperature, after loading the red coke, gradually adjust the speed of the circulating fan to 40% or 600 r / min to quickly introduce the sensible heat of the red coke into the boiler system for heat exchange.

[0117] 5.8 During the boiler drum heating and pressurization process, pay attention to the management of drainage and blowdown in various parts of the boiler. When the main steam temperature of the boiler reaches 420℃, start the desuperheating water regulating valve;

[0118] 5.9 After loading the red coke, the temperatures at points T5 and T6 will continue to rise and then begin to fall. At this point, the circulating fan speed should be gradually reduced to 15% or 300 r / min, depending on the actual situation. This is to avoid the O2 content in the circulating gas exceeding 5% and to prevent the temperature difference between T5 and T6 from being too large, which would affect the heating process.

[0119] 5.10 When the temperatures of T5 and T6 drop to meet the heating requirement of 10℃ / h, preparations can be made to load the second batch of red coke.

[0120] 5.11 0.5 hours after the second batch of red coke is loaded, adjust the amplitude of the vibrating feeder to 10Hz;

[0121] 5.12 When the material level in the dry quenching furnace is below 11 meters, the heating rate is mainly controlled by adjusting the circulating fan speed and the red coke loading frequency; when the material level is above 11 meters, it can be controlled by adjusting the coke discharge rate and the circulating air volume.

[0122] 5.13 When the boiler inlet temperature exceeds 650℃, stop nitrogen supplementation in the system, open the middle valve and air inlet valve to introduce air into the system to reduce the concentration of combustible components such as H2 and CO in the circulating gas;

[0123] 5.14 When the T6 temperature reaches above 960℃, the red coke heating process ends and normal production can resume.

Claims

1. A method for dry quenching coke oven, characterized in that... Includes the following: (1) The gas oven was replaced with a red coke oven. By controlling the coke loading speed, coke discharge volume and circulating air volume, the impact of red coke on the masonry was minimized. (2) Increase the amount of cold coke charged before the oven is dried to ensure that coke can be discharged normally in the early stage of oven drying and eliminate the risk of suspended material; (3) By fine-tuning the circulating air volume, low-pressure steam volume, air introduction volume, and opening of each vent valve, the problem of uneven heating caused by steam pressure and temperature fluctuations during the warm air drying process can be eliminated. The dry quenching coke oven method includes the following: Step 1, Preparation: Load the prepared cold coke into the auxiliary tank of the coke car, and use the interval between unloading to load it into the dry quenching furnace of the oven to be dried. When loading cold coke, control the loading of one tank of coke into the dry quenching furnace within 15 minutes. Step 2: Adjust the status of each valve in the dry quenching furnace system: An air inlet regulating plate is installed at the emergency vent valve to control the amount of air entering the dry quenching furnace; the dry quenching furnace inlet baffle is opened; the circulating fan inlet flap is opened; the air inlet valve is closed; the 1DC and 2DC type valves are stopped; all water discharge points in the dry quenching furnace cooling chamber are opened; the maintenance flat gate is opened; the pre-storage chamber pressure regulating valve is closed; the quick-cut valve is closed; and the gas analyzer sampling tube is closed. Step 3: Close all manhole doors of the dry quenching furnace system; Step 4: Warm air drying (1) First, bypass the water circuit of the low-pressure economizer and use the deaerator circulation pump to heat up the deaerator; during the deaerator heating process, start the boiler water supply and gradually replace the room temperature water in the boiler, and send in low-pressure steam for heating. When the steam drum pressure reaches 0.6MPa, introduce steam into the steam drum. (2) Adjust the valve opening according to the heating requirements: when the boiler inlet temperature T6 rises to 150℃, turn on the circulating fan; control the air volume at the minimum, and adjust the circulating air volume by adjusting the fan speed; (3) After the circulating fan is started, the emergency vent valve is opened to start warm air drying. At this time, the temperature of the dry quenching furnace is low and the boiler inlet temperature is high. The heating rate is controlled at 5±1℃ / h. (4) During the warm air drying period, the inlet temperature T2 of the dry quenching furnace should be the main management temperature, and the operation should be strictly carried out according to the heating curve of the dry quenching furnace; the heating rate is 5±1℃ / h, and it is maintained after reaching 140±5℃. (5) As the temperature T2 increases, the heating rate gradually decreases. At this time, the heating rate is controlled by adjusting the speed of the circulating fan and the opening of the emergency relief valve. (6) During the warm air drying period, water should be drained at each water outlet, and the water should be manually drained once per shift; (7) When no white steam comes out when the furnace cover is opened, and the temperature of T2 is above 140℃, the warm air drying is over; Step 5, nitrogen replacement: After the warm air drying is completed, adjust the circulating fan speed to 300 r / min, close the furnace cover, close the emergency vent valve, keep the pre-storage chamber pressure regulating valve and quick-cut valve closed, and keep the pre-storage chamber vent valve open, controlling the pre-storage chamber pressure to 0-50 Pa; open the main nitrogen valve, fully open the nitrogen bypass valve before or after the fan, and control the nitrogen flow rate to 3000 m³ / min. 3 Once the speed exceeds a certain level, nitrogen purging begins; after nitrogen purging is completed, the process of loading red coke and heating up the temperature is carried out. Step 6: Heat the red caramel: (1) After the warm air drying is completed, start the coke discharge operation. Control the coke discharge rate to 60t / h for coke discharge test. Stop the coke discharge when the material level is 3 meters and prepare for the red coke loading operation. (2) When loading red coke, the main management temperature is T5, and the heating rate is controlled at 10℃ / h. The auxiliary management temperature is T6, and the heating rate is controlled at 10℃ / h. (3) Before loading coke, gradually adjust the speed of the circulating fan to 450 r / min, and prepare to load red coke to raise the temperature; (4) 15 minutes before the first batch of red coke is loaded, the vibration feeder amplitude is adjusted to 5Hz, the coke discharge rate is controlled at 20t / h, and the lower cold coke is always in a flowing state during the loading of red coke. (5) When using the flow method to load coke, the elevator needs to be switched to manual operation, and the coke should be flowed into the dry quenching furnace intermittently over 15-20 minutes. (6) To avoid a significant increase in T5 temperature, after loading the red coke, gradually adjust the speed of the circulating fan to 600 r / min; (7) During the process of heating and pressurizing the boiler drum, pay attention to the management of drainage and sewage discharge in various parts of the boiler; when the main steam temperature of the boiler reaches 420℃, start the desuperheating water regulating valve; (8) After loading the red coke, the temperatures of T5 and T6 will continue to rise and then begin to fall. At this time, the speed of the circulating fan will be gradually reduced to 300±30r / min according to the actual situation. When the temperatures of T5 and T6 drop to meet the heating requirement of 10±1℃ / h, prepare to load the second batch of red coke. (9) 0.5 hours after the second batch of red coke is loaded, adjust the amplitude of the vibrating feeder to 10±2Hz; (10) When the boiler inlet temperature T6 is above 960℃, the red coke heating ends and normal production resumes.

2. The dry quenching coke oven method according to claim 1, characterized in that: In step one, the amount of cold coke loaded is 140-160 tons.

3. The dry quenching coke oven method according to claim 1, characterized in that: In step three, the manholes of the dry quenching furnace system include: (1) the manholes on the boiler; (2) the manholes on the circulating gas system; (3) the manholes of the primary and secondary dust collectors; (4) the manholes on the dry quenching furnace; and (5) the manholes of the discharge device.

4. The dry quenching coke oven method according to claim 1, characterized in that: During the warm air drying process, in order to control the heating rate at 5±1℃ / h, the following measures are taken: ① The circulating fan is controlled to operate at 5% of its rated speed; ② The emergency vent valve is fully opened; if the heating rate is fast, the circulating fan speed is reduced or the opening of the emergency vent valve is increased; if the heating rate is slow, the circulating fan speed is increased or the opening of the emergency vent valve is decreased. During the warm air drying process, the deviation between the actual temperature and the planned temperature is controlled within ±10℃, while the temperature of the pre-storage chamber is controlled to be above 120℃.

5. The dry quenching coke oven method according to claim 1, characterized in that: In order to control the appropriate temperature during the warm air drying process, the adjustment methods used include: ①When the T5 temperature rises too quickly, reduce the amount of low-pressure steam blow-in, increase the amount of circulating air, increase the amount of introduced air, and increase the opening of the furnace cover; ②When the temperature rises slowly at T5, increase the amount of low-pressure steam introduced and reduce the amount of air introduced; ③When the boiler water temperature rises but the circulating gas temperature does not rise, reduce the amount of air introduced; ④ When the T5 temperature and the circulating gas temperature rise too quickly, increase the opening of the furnace top cover, increase the amount of air released, and increase the amount of air introduced. ⑤ When the temperature difference between T2 and T5 increases, if the temperature of the circulating gas is greater than that of T5, the circulating air volume should be increased. ⑥ When the outlet pressure P1 of the circulating fan is lower than the reference value, increase the circulating air volume. If the effect is not significant, close the furnace top vent valve or reduce the furnace cover opening.

6. The dry quenching coke oven method according to claim 1, characterized in that: During nitrogen purging, monitor the changes in oxygen content in the gas analyzer. After 1.5 hours, if the gas analyzer shows an oxygen content of <5%, use a portable alarm to measure the O2 content of the vent gas at the vent valve in the pre-storage chamber. When the oxygen content is confirmed to be <5%, the nitrogen purging is considered complete.

7. The dry quenching coke oven method according to claim 1, characterized in that: During the process of charging red coke and raising the temperature, when the material level in the dry quenching furnace is 10-11 meters, the heating rate is controlled by adjusting the speed of the circulating fan and the frequency of red coke charging; when the material level is above 11 meters, the heating rate is controlled by adjusting the amount of coke discharged and the amount of circulating air; when the boiler inlet temperature T6 ≥ 650℃, nitrogen supplementation in the system is stopped, and the middle valve and air inlet valve are opened to introduce air into the system to reduce the concentration of combustible components in the circulating gas.