Method and device for on-line rapid treatment of hanging and coke floating at initial stage of use of large dry quenching furnace

Abstract

The invention relates to a method and a device for quickly treating hanging materials and coke floating at the initial stage of use of a large dry quenching furnace on line. The air volume of a circulating fan of the dry quenching furnace is reduced to the minimum value of a design value; the coke discharging amount is controlled, and the friction carrying of coke is increased; the air cannon sequentially blows from top to bottom in the radial direction of the dry quenching furnace; after one cycle of injection is finished, if the coke discharge temperature still does not exceed the heat-resistant temperature of the coke discharge belt, entering the next injection cycle; oscillating and discharging coke; repeatedly blowing until the hanging material is relieved and falls off; and the coke floating in the chute area is promoted to slide back to the cooling chamber. The method has the advantages of solving the problem of material hanging at the initial stage of large-scale dry quenching production, shortening the standard production time, rapidly reaching the standard production and improving the production efficiency. An air cannon is used for forming a paroxysmal air source, the air source with large local pressure intensity directly acts on a coke sticking and hanging part, so that the hanging part is loosened, and the coke falls off under the combined action of friction force generated by descending of the coke.

Description

Technical Field

[0001] The invention belongs to the field of dry quenching coke oven production, and in particular relates to a method and a device for online rapid treatment of material hanging and coke floating in the initial stage of commissioning of a large dry quenching oven. Background Art

[0002] With the large-scale construction of blast furnaces and coke ovens, the large-scale dry coke quenching equipment is the future development direction. At present, the processing capacity of existing dry coke quenching equipment in my country is 65~260t / h. It can be divided into small, medium and large according to the processing capacity. The small processing capacity is less than 125t / h, the medium processing capacity is 125~170t / h (excluding 170t / h), and the large processing capacity is 170~260t / h. The time for a large dry coke quenching unit to reach full production is generally 20 to 30 days. Because each overhaul of the dry coke quenching unit takes more than a month, the large-scale dry coke quenching takes a long time to reach full production after each overhaul, resulting in production difficulties and low dry quenching rate. It is urgent to study methods for rapid production of large-scale dry coke quenching units.

[0003] The reasons for the long production time: when the dry quenching furnace is finished, the large dry quenching furnace has a large furnace structure, and the time for building the furnace manhole and replacing the gas in the furnace are extended to a certain extent, so the furnace temperature drops more than that of the small dry quenching furnace. When the large dry quenching furnace is put into production with red coke, the temperature of the temperature measuring points T3, T4 and the chute is lower than that of T3, T4 and the chute after the small and medium-sized dry quenching is put into production, and the wall temperature does not reach the temperature for the tar-like adhesive to melt. As a result, the chute of the dry quenching furnace is blocked by sticky coke, and the cooling chamber is hung with material. In addition, the newly put into production dry quenching furnace has not been through normal production conditions, the water vapor has not been completely driven away, and the working surface has not been rubbed by coke. It is manifested that the coke in the furnace flows downward in a core-pulling state, and the central part is discharged very quickly. In severe cases, red coke is discharged from the dry quenching furnace. In order to quickly cool the central red coke, the circulating air volume is increased, and the surrounding coke continues to cool. The temperature of the cooling wall bricks was also gradually cooled, causing the coke hanging to continue to worsen. The surrounding coke hanging range was getting wider and wider, while the central lower coke range was gradually reduced. The coke at the chute and hanging on the cooling wall formed a solid ring-shaped plate agglomeration that could not fall down. The coke at the chute floated up and seriously blocked the circulation air ventilation of the chute, resulting in an increasing negative pressure at the boiler inlet. The boiler inlet temperature did not increase with the increase of the circulating air volume, and the pressure in the pre-storage chamber fluctuated frequently. After gradually increasing the circulating air volume, the circulation system became more and more chaotic.

[0004] At present, the common method to solve the problem of material hanging in the cooling chamber of the CDQ furnace is to use intermittent material pulling for large and small coke discharges, and gradually remove the hanging material by using the friction of coke during large-scale coke discharge and the shock force of frequently changing the material discharge speed. This method generally reaches full production in about 30 days, and the time for serious hanging material is longer, mainly because some serious hanging material cannot be removed fundamentally. This causes long-term uneven material discharge in the cooling chamber of the CDQ furnace, and uneven and continuously high coke discharge temperatures. While intermittent material pulling solves the problem of hanging material, the corbel and annular beam structure of the CDQ furnace are damaged due to the long-term instantaneous change of the temperature field at the corbel of the ramp. After the CDQ was put into production, the corbel bricks of some of the CDQs cracked and fell off, bringing irreversible damage risks to the CDQ. And this method cannot solve the problem of coke sticking and hanging material at the ramp mouth. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for online rapid treatment of coke hanging and coke floating in the initial stage of commissioning of a large-scale dry quenching furnace, which uses an air cannon device to form a paroxysmal air source to directly act on the coke sticking hanging and the coke floating on the chute blocking area and position, so as to promote the hanging to fall off quickly and solve the problem of long production time caused by uneven material feeding.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A method for quickly treating the initial hanging of materials and coke floating in a large-scale dry quenching furnace online comprises the following steps:

[0008] (1) Reduce the air volume of the CDQ furnace's circulating fan to the minimum design value to ensure that the negative pressure in the CDQ furnace's ramp area is minimized and the suction at the ramp mouth is minimized;

[0009] (2) Control the amount of coke discharge. When the coke discharge temperature does not exceed the heat-resistant temperature of the coke discharge belt, increase the amount of coke discharge to speed up the flow of coke in the CDQ furnace and increase the friction entrainment of coke.

[0010] (3) The air cannon sprays along the radial direction of the CDQ furnace from top to bottom; the air cannon spray pressure is 0.3-0.6MPa;

[0011] (4) After one cycle of spraying is completed, observe the coke discharge temperature. If the coke discharge temperature still does not exceed the heat resistance temperature of the coke discharge belt, enter the next spraying cycle and repeat step (3) until the coke discharge temperature exceeds the heat resistance temperature of the coke discharge belt. Then, spraying is terminated; the air volume of the circulating fan is increased, and the coke discharge volume is reduced at the same time;

[0012] (5) When the average coke discharge temperature returns to less than 120°C, the next step of oscillating coke discharge can be carried out, that is, large and small coke discharge volumes are carried out alternately, with an alternating interval of 10 minutes; the circulating air volume is increased as the coke discharge volume increases, and the circulating air volume is reduced as the coke discharge volume decreases;

[0013] (6) After 40 minutes of vibration and de-coking, repeat the blowing in step (3) until the hanging material is relieved and falls off;

[0014] (7) After the hanging material falls off, the air cannons in the chute area are opened in sequence for blowing, and the coke discharge volume is increased to 80% of the designed maximum value. The coke discharge temperature does not exceed 250°C, and the air-to-material ratio is reduced to cause the coke floating in the chute area to slide back to the cooling chamber.

[0015] The operating frequency of the circulating fan in step (1) is 10 to 50 hours. Z .

[0016] In step (3), the air cannon sprays toward the weak points of the hanging material.

[0017] A device for online rapid treatment of initial hanging of materials and coke floating in a large-scale dry quenching furnace comprises an air cannon, a purge pipeline and a gas storage tank, wherein the blowing pipe of the air cannon is connected to the purge pipeline, the purge pipeline is connected to the bottom area of ​​the cooling chamber area and the ramp area inside the dry quenching furnace, the purge pipeline is arranged obliquely downward along the inner wall of the dry quenching furnace, and the angle between the purge pipeline and the vertical direction of the dry quenching furnace is 30° to 45°, and the angle between the purge pipeline and the ramp of the dry quenching furnace is 15° to 20°; the gas storage tank is connected to the air cannon; the gas storage tank is a nitrogen gas storage tank.

[0018] The air cannons are installed on the peripheral platform of the CDQ furnace, and the distance between the air cannons is 0.9 to 1 meter.

[0019] The purge pipeline is connected with a solenoid valve.

[0020] The purge pipeline is arranged along the radial direction of the CDQ furnace.

[0021] The purge pipes are arranged in multiple layers along the longitudinal direction in the cooling chamber area and the bottom area of ​​the ramp area inside the dry quenching furnace.

[0022] The purge pipe is connected to the dry quenching furnace at a flange.

[0023] The flange is connected with a blind plate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention solves the problem of material hanging in the early stage of large-scale dry coke quenching, shortens the time to reach full production, quickly reaches full production and improves production efficiency. The present invention has a simple structure, uses an air cannon to form a paroxysmal gas source, and the gas source with a relatively large local pressure directly acts on the coke-sticking hanging part, loosens the hanging part, and the friction generated by the coke falling acts together to make it fall off. At the same time, the purge pipeline is tilted downward, and the angle with the vertical direction of the dry quenching furnace is 30° to 45°, which promotes the rapid falling of the hanging material in the dry quenching furnace, protects the structural stability of the refractory material of the dry quenching furnace, improves the dry quenching rate, and ensures the long-term continuous production of the dry quenching system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 yes Figure 1 A partial enlarged view of .

[0028] Figure 3 It is a top view of the present invention.

[0029] Figure 4 It is the control principle diagram of the present invention.

[0030] In the figure: 1- air cannon 2- purge pipe 3- peripheral platform 4- dry quenching furnace 5- flange 6- T3 temperature measuring point 7- T4 temperature measuring point. DETAILED DESCRIPTION

[0031] The present invention is described in detail below in conjunction with the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0032] See Figure 1-Figure 4 , a method for online rapid treatment of initial loading and coke floating in a large CDQ furnace, air cannon 1 uses nitrogen as the air source of air cannon 1, and cooperates with corresponding circulating air volume adjustment and coke discharge volume adjustment means to achieve online rapid treatment of initial loading and coke floating in a large CDQ furnace. Specifically, the following steps are included:

[0033] (1) Reduce the air volume of the circulating fan of the CDQ furnace 4 to the minimum of the design value. At this time, the operating frequency of the circulating fan is 10-50Hz. The circulating air volume during the injection period is set to the minimum air volume, and the operating frequency is 10Hz. Ensure that the negative pressure in the chute area of ​​the CDQ furnace 4 (the pressure is determined by the suction force of the circulating fan inlet) is reduced to a minimum, and the suction force at the chute entrance is minimized; if the air volume is too large, it will affect the injection effect and cause the coke to float further in the chute area;

[0034] (2) Control the amount of coke discharge. When the coke discharge temperature does not exceed the heat resistance temperature of the coke discharge belt, increase the amount of coke discharge as much as possible to accelerate the flow rate of coke in the CDQ furnace 4 and increase the friction entrainment of coke. This method is to cooperate with the opening of the air cannon 1 device to cause the coke at the chute to slide quickly back to the cooling chamber.

[0035] The coke discharge belt is a belt conveyor for receiving the coke discharged from the bottom of the dry quenching furnace 4 (referred to as the coke discharge belt), and its heat-resistant temperature is below 250°C.

[0036] (3) The air cannon 1 sprays in sequence along the radial direction of the dry quenching furnace 4 from top to bottom; when the air cannon 1 is used, a certain point or multiple weak points of hanging materials are first selected, and the air cannon 1 arranged in the point area is manually or automatically controlled to spray in sequence along the radial direction of the dry quenching furnace 4 from bottom to top. The air cannon 1 facing each layer is controlled to spray in sequence. The time of each spraying is controlled to be less than 5 minutes, and the interval time is 2 to 3 seconds. The spraying pressure of the air cannon 1 is 0.3 to 0.6 MPa; the air cannon 1 selects the weak point of hanging materials to spray, so that the hanging materials are pulled apart at one point, and the hanging materials at each point in the circumferential direction are successively loosened. As the coke discharge continues, the hanging materials at each point can be pulled apart successively and easily separated from the furnace wall. During the spraying period, the circulating air pressure is stable, and the pressure fluctuation value of the pre-storage chamber of the dry quenching furnace 4 is between ±200Pa. The oxygen volume concentration of nitrogen is less than 1% when the air cannon 1 is working.

[0037] (4) After one cycle of injection is completed, observe the coke discharge temperature. If the coke discharge temperature still does not exceed the heat resistance temperature of the coke discharge belt, enter the next injection cycle and repeat step (3) until the coke discharge temperature exceeds the heat resistance temperature of the coke discharge belt (250°C). Then, the injection is terminated; the air volume of the circulating fan is increased, and the coke discharge volume is reduced at the same time;

[0038] (5) When the average coke discharge temperature returns to <120°C, the next step of oscillating coke discharge can be carried out, that is, large and small coke discharges are carried out alternately, and the alternating time interval is 10 minutes; as the coke discharge amount increases or decreases, the circulating air volume is also adjusted at the same time. During coke discharge, the air-to-material ratio of the CDQ (1430Nm 3 / h or less) to control the circulating air volume (gas-to-material ratio, i.e. the circulating air volume used to extinguish 1 ton of coke) to avoid further accumulation of coke on the chute and aggravation of coke floating due to excessive gas-to-material ratio.

[0039] (6) After 40 minutes of vibration and de-coking, repeat the blowing in step (3) until the hanging material is relieved and falls off.

[0040] (7) After the hanging material falls off, open the air cannon 1 in the ramp area for spraying, and at the same time increase the coke discharge volume to 80% of the designed maximum value, the coke discharge temperature does not exceed 250°C, and the CDQ gas-to-material ratio is reduced as much as possible, and the CDQ gas-to-material ratio is controlled within the conventional CDQ gas-to-material ratio (1430Nm 3 The downward blowing effect of the spray on the coke floating in the chute area, the downward friction and entrainment of the coke discharge, and the reduction of the suction of the circulating wind in the chute area after the gas-to-material ratio are reduced, all work together to cause the coke floating in the chute area to slide back to the cooling chamber.

[0041] See Figure 1-Figure 3, a device for online rapid treatment of material hanging and coke floating in the initial stage of commissioning of a large-scale dry quenching furnace, comprising an air cannon 1, a purge pipe 2, and a gas storage tank, wherein the gas storage tank is connected to the air cannon 1 to provide nitrogen for the air cannon 1. In actual production, it was found that the material hanging of the dry quenching furnace 4 mainly occurred in the cooling chamber of the dry quenching furnace 4 (including the T3 and T4 temperature measuring points 6 and 7 areas), and the coke accumulation and floating occurred in the bottom area of ​​the ramp, so the air cannon 1 was also arranged in the cooling chamber of the dry quenching furnace 4 and the ramp area of ​​the dry quenching furnace 4. Air cannons 1 are arranged in multiple layers in the circumferential direction of the cooling chamber, and the air cannons 1 of the upper layer are arranged directly above the air cannons 1 of the lower layer. The distance between adjacent air cannons 1 in the longitudinal and transverse directions is 0.9 to 1 meter, and the circumferential encirclement can be less than 0.9 meters and not more than 1 meter. Air cannons 1 are arranged 0.7 meters upward from the bottom of each ramp in the ramp area, with a total of 24 groups of air cannons 1. The air cannon 1 is installed on the outer platform 3 of the dry quenching furnace 4, the blowing pipe of the air cannon 1 is connected to the purge pipe 2, the purge pipe 2 is connected to the bottom area of ​​the cooling chamber area and the ramp area inside the dry quenching furnace 4, and the purge pipe 2 is arranged obliquely downward along the inner wall of the dry quenching furnace 4. In the cooling chamber area, the angle between the purge pipe 2 and the vertical direction of the dry quenching furnace 4 is 30° to 45°; in the ramp area, the angle between the purge pipe 2 and the oblique downward direction of the ramp area of ​​the dry quenching furnace 4 is 15 to 20°; the refractory material inside the dry quenching furnace 4 is masonry reserved with holes in the same blowing direction, so that the blowing gas is sprayed obliquely downward along the ramp of the dry quenching furnace 4 and the edge of the inner wall of the cooling chamber.

[0042] A solenoid valve is connected to the purge pipe 2, and the solenoid valve is set in front of the submerged pulse valve of the air cannon 1 to prevent the gas pressure of other pulse valves from being affected by the leakage of a pulse valve. When the air cannon 1 is used for spraying, the solenoid valve and the pulse valve are opened at the same time. When closing, the solenoid valve is closed first and then the pulse valve.

[0043] The air cannon 1 is a strong airflow of compressed gas that suddenly ejects, and directly rushes into the blocked fault area of ​​the dry quenching furnace 4 storing bulk materials at supersonic speed. This sudden release of expansion shock wave overcomes the static friction of the material and restores the flow of the material in the dry quenching furnace 4. The air cannon 1 is installed on the outer platform 3 of the dry quenching furnace 4, and the gas purge pipeline 2 connects the cooling chamber area inside the dry quenching furnace 4 and the bottom area of ​​the ramp area. When the high-pressure gas is connected, it acts on the hanging area to loosen and fall off.

[0044] The purge pipe 2 is arranged radially along the dry quenching furnace 4. The purge pipe 2 is arranged in multiple layers in the longitudinal direction in the cooling chamber area and the bottom area of ​​the ramp area inside the dry quenching furnace 4. The number and number of layers of the purge pipe 2 are determined according to the size of the dry quenching furnace 4. The connection between the purge pipe 2 and the dry quenching furnace 4 is connected with a flange 5. A blind plate is connected to the flange 5, and the blind plate is added during normal production to block gas leakage in the furnace.

[0045] The gas storage tank is a nitrogen gas storage tank. The distance between adjacent air cannons 1 in the longitudinal and transverse directions is 0.9 to 1 meter. In order to facilitate the effective blowing of the air cannon 1, the air cannon 1 is of an adjustable gas pressure type, and the pressure adjustment range is 0.3 to 0.6 MPa.

[0046] The gas storage tank provides nitrogen to the air cannon 1. When the solenoid valve is opened, the air cannon 1 sprays nitrogen into the dry quenching furnace 4 through the purge pipe 2. The air cannons 1 arranged in layers according to angles are sprayed regularly in coordination with the spraying time interval. According to the different hanging parts, the spraying time interval, spraying position, and purge frequency are adjusted to loosen the hanging parts, and the friction generated by the coke falling together makes it fall off. During the spraying process, all air cannons 1 are inspected to prevent the reduction of air cannon 1 efficiency and waste of energy media due to gas leakage.

[0047] Through the above specific implementation, the technical personnel in the relevant technical field can easily implement the present invention. However, it should be understood that the present invention is not limited to the above specific implementation. On the basis of the disclosed implementation, the technical personnel in the relevant technical field can arbitrarily combine different technical features to achieve different technical solutions. Due to the limited space and to make the specification concise, the various solutions composed of these combinations are not described one by one. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for quickly treating the initial material hanging and coke floating of a large-scale dry quenching furnace online, characterized in that: The following steps are involved: (1) Reduce the air volume of the CDQ furnace's circulating fan to the minimum design value to ensure that the negative pressure in the CDQ furnace's ramp area is minimized and the suction at the ramp mouth is minimized; (2) Control the amount of coke discharge. When the coke discharge temperature does not exceed the heat-resistant temperature of the coke discharge belt, increase the amount of coke discharge to speed up the flow of coke in the CDQ furnace and increase the friction entrainment of coke. (3) The air cannon sprays along the radial direction of the CDQ furnace from top to bottom; the air cannon spray pressure is 0.3-0.6MPa; (4) After one cycle of spraying is completed, observe the coke discharge temperature. If the coke discharge temperature still does not exceed the heat resistance temperature of the coke discharge belt, enter the next spraying cycle and repeat step (3) until the coke discharge temperature exceeds the heat resistance temperature of the coke discharge belt. Then, spraying is terminated; the air volume of the circulating fan is increased, and the coke discharge volume is reduced at the same time; (5) When the average coke discharge temperature returns to less than 120°C, the next step of oscillating coke discharge can be carried out, that is, large and small coke discharge volumes are carried out alternately, with an alternating interval of 10 minutes; the circulating air volume is increased as the coke discharge volume increases, and the circulating air volume is reduced as the coke discharge volume decreases; (6) After 40 minutes of vibration and decoking, repeat the blowing in step (3) until the hanging material is relieved and falls off; (7) After the hanging material falls off, the air cannons in the chute area are opened in sequence for blowing, and the coke discharge volume is increased to 80% of the designed maximum value. The coke discharge temperature does not exceed 250°C, and the air-to-material ratio is reduced to cause the coke floating in the chute area to slide back to the cooling chamber.

2. The method for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 1 is characterized in that: The operating frequency of the circulating fan in step (1) is 10 to 50 hours. Z .

3. The method for online rapid treatment of coke hanging and coke floating in the initial stage of large-scale dry quenching furnace operation according to claim 1 is characterized in that: In step (3), the air cannon sprays toward the weak points of the hanging material.

4. A device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace used in the method according to any one of claims 1 to 3, characterized in that: It includes an air cannon, a purge pipe, and a gas storage tank. The blowing pipe of the air cannon is connected to the purge pipe. The purge pipe is connected to the cooling chamber area and the bottom area of ​​the ramp area inside the dry quenching furnace. The purge pipe is arranged downward along the inner wall of the dry quenching furnace, and the angle between the purge pipe and the vertical direction of the dry quenching furnace is 30° to 45°, and the angle between the purge pipe and the ramp of the dry quenching furnace is 15° to 20°; the gas storage tank is connected to the air cannon; the gas storage tank is a nitrogen gas storage tank.

5. The device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 4 is characterized in that: The air cannons are installed on the peripheral platform of the CDQ furnace, and the distance between the air cannons is 0.9 to 1 meter.

6. The device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 4 is characterized in that: The purge pipeline is connected with a solenoid valve.

7. The device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 4 is characterized in that: The purge pipeline is arranged along the radial direction of the CDQ furnace.

8. The device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 4 is characterized in that: The purge pipes are arranged in multiple layers along the longitudinal direction in the cooling chamber area and the bottom area of ​​the ramp area inside the dry quenching furnace.

9. The device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 4 is characterized in that: The purge pipe is connected to the dry quenching furnace at a flange.

10. The device for online rapid treatment of initial material hanging and coke floating in a large-scale dry quenching furnace according to claim 9, characterized in that: The flange is connected with a blind plate.

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