On-line rapid replacement method for in-situ overhaul flue turning plate of coke oven

Abstract

A coke oven in-situ overhaul flue turning plate on-line rapid replacement method is characterized by comprising the following steps that a, a turning plate base is welded and fixed to an upper structure of a turning plate through a channel steel frame, and the turning plate base and the turning plate form a whole; b, reserving a 50mm gap between the channel steel frame and the turning plate; c, each side of the turning plate fan blade needs to be shortened by 50mm compared with that of the original turning plate fan blade; d, reserving a 2mm gap between the channel steel frame and each side of the original flue wall; and e, arranging a rotating shaft limiting shaft sleeve at the part, close to the upper structure of the turning plate, of the rotating shaft without pouring concrete on the flue turning plate base. The coke oven in-situ overhaul flue turning plate on-line rapid replacement method has the advantages that the problem that under the normal production condition of a coke oven flue, personnel cannot enter a high-temperature, toxic, closed and limited-space flue to fix a turning plate base is solved; the flue turning plate base and the flue turning plate are effectively fixed through transformation, and the overall stability of the flue turning plate structure is improved by additionally arranging the rotating shaft limiting sleeve.

Description

TECHNICAL FIELD

[0001] The present application relates to a coke oven flue flap, in particular to a coke oven in-place overhaul flue flap online quick replacement method. BACKGROUND

[0002] As an important equipment for coal coking, coke oven runs in high temperature environment for a long time, and its key parts such as carbonization chamber refractory, flue flap, heating system and gas pipeline are prone to aging and damage. Typical problems include: severe erosion of carbonization chamber refractory, leakage of furnace wall, blockage of flue gas passage, aging and leakage of gas system, etc., which leads to uneven furnace temperature, decreased coke maturity, reduced thermal efficiency, increased environmental protection pressure and a series of problems. With the increase of furnace age, the maintenance cost of coke oven increases year by year, and has shown the trend of "three high" of "high energy consumption, high maintenance cost and high environmental protection pressure". In order to solve the above problems, in-place overhaul of coke oven is needed, including comprehensive renovation and replacement of flue, furnace wall, flap and auxiliary structure.

[0003] The traditional coke oven overhaul method is mainly cold repair, that is, after the coke oven is completely stopped and cooled to a safe temperature, workers enter the internal structure of the flue to carry out removal and replacement work. However, in modern coking plants, especially in large joint steel enterprises, coke ovens are often arranged in groups, and multiple coke ovens share a set of flue and chimney system. Once all of them are stopped, it will seriously affect the production of coke, gas supply and the continuous operation of downstream processes, and the production system will face great pressure. Therefore, in recent years, the industry has gradually developed an "online lapping transformation" mode, that is, part of the coke ovens in the same group are partially overhauled, and the other coke ovens remain in production state, so as to realize the minimum disturbance of coke and gas capacity (see "Research on Online Maintenance and Local Transformation Technology of Coke Oven Group", Thermal Energy Engineering, No. 3, 2016).

[0004] However, in the online lapping transformation mode, since the flue system needs to remain in continuous operation state, its interior is always in a closed environment of high temperature, toxicity and lack of oxygen, which is a high-risk limited space, and workers cannot enter the flue to carry out traditional removal or installation work. In particular, the structure of coke oven flue flap, because it has existed problems such as rust, shaft wear, base damage and air leakage after being used for a generation of furnace age, if the flap and its base cannot be quickly replaced online, it will directly affect the sealing performance and heat flow distribution of the flue, and further affect the operation safety and thermal efficiency of the whole coke oven group.

[0005] There are some optimization schemes for the flue flap structure of coke oven in the current disclosed patents, but most of them are based on cold repair replacement, and cannot break through the limitation of "overall replacement in high-temperature state online". For example, CN104582131A discloses a coke oven flue flap structure, which still adopts the traditional concrete base fixing method and is only suitable for cold repair conditions; the flap replacement method proposed in CN101215941A improves the operation convenience, but the installation steps require personnel to operate inside the flue; the construction scheme of CN109998034A also emphasizes replacement after flue cooling and ventilation, which is obviously not suitable for online overhaul scene.

[0006] In addition, although there are some researches on the maintenance and updating of coke oven flaps in documents such as "Coking Technology", "Iron and Steel", "Metallurgical Energy" and the like, they are mostly limited to fault diagnosis or standard installation process, and there is no specific method for realizing synchronous replacement of flaps and bases under the conditions of continuous operation and high-temperature sealing of coke oven flues. The existing technologies do not provide a solution that can realize online and rapid replacement of flue flap structure without personnel entering the flue, and has reliable sealing and stable performance.

[0007] Therefore, it is urgent to propose a new structure and installation method, which can realize rapid replacement and stable fixation of the overall structure of flaps and bases under the premise that the coke oven flue is in normal operation and personnel cannot enter, and meet the requirements of sealing and function recovery of coke oven flue in online lap joint modification project. SUMMARY

[0008] The purpose of the present application is to provide a safe and reliable method for online rapid replacement of coke oven flue flap during in-situ overhaul.

[0009] To achieve the above-mentioned purpose, the technical solution of the present application is as follows: A method for online rapid replacement of coke oven flue flap during in-situ overhaul, two coke ovens are coke ovens of the same group, the waste gas generated by the two coke ovens is collected through a collecting flue and then discharged to the same chimney, when the 6A coke oven is modified, the adjacent 5B coke oven is in normal production and operation state, so the collecting flue and the chimney do not have complete shutdown conditions, and the method comprises the following steps: a. Welding and fixing the flap base to the upper structure of the flap with a channel steel frame to form an integral whole with the flap; b. Reserving a 50mm gap between the channel steel frame and the flap to ensure the original air leakage rate under the full-closed state of the flue flap; c. Shortening the flap fan blade by 50mm on each side compared with the original flap fan blade, and shortening the total size of the flap from 2100mm to 2000mm; d. Reserving a 2mm gap between the channel steel frame and the original flue wall on each side to facilitate the smooth installation of the modified flue flap; e、The flue flap base does not need to be poured with concrete, and a pivot limiting sleeve is arranged at the position where the pivot is close to the upper structure of the flap, so as to ensure the overall stability of the flue flap structure.

[0010] The coke oven in-situ overhaul flue flap online quick replacement method of the present application can be further realized by the following technical measures.

[0011] The aforementioned method, wherein the channel steel frame size specification is 3445x2196mm.

[0012] The aforementioned method, wherein the channel steel frame is made of 10# channel steel.

[0013] After the above technical solution is adopted, the coke oven in-situ overhaul flue flap online quick replacement method of the present application has the following advantages: 1. The problem that personnel cannot enter the high-temperature, toxic, and closed limited space in the flue to fix the flue base under normal production conditions of the coke oven flue is solved; 2. The flue flap transformation effectively fixes the flue flap base and the flue flap; 3. The pivot limiting sleeve is added to improve the overall stability of the flue flap structure. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The coke oven planar arrangement of the embodiment of the present application is shown in the figure. Figure 2 The original flue flap structure of the embodiment of the present application is shown in the figure. Figure 3 The transformed flue flap structure of the embodiment of the present application is shown in the figure.

[0015] In the figure: 1, flap; 2, flap base; 3, flue wall; 4, limiting sleeve; 5, flap base fixing frame. DETAILED DESCRIPTION

[0016] The present application is further described below in combination with the embodiments and the accompanying drawings.

[0017] Embodiment 1 Please refer to Figure 1 , Figure 1 The coke oven planar arrangement of the embodiment of the present application is shown in the figure. As shown in the figure, the coke oven in-situ overhaul online lap transformation is performed on two coke ovens as the same oven group, the waste gas generated by the two coke ovens is collected through the collection flue and then discharged to the same chimney, when the 6A coke oven is transformed, the adjacent 5B coke oven is in the normal production and operation state, therefore, the collection flue and the chimney do not have complete shutdown conditions, the flue is a high-temperature, toxic, and closed high-risk limited space, and the flue flap cannot be replaced and fixed in the flue by using the conventional method.

[0018] Figure 2The figure is a schematic view of the original flue flap structure of the embodiment of the present application. The original flue flap installation method: during the installation of the coke oven in a cold state, personnel enter the flue to position the flap base, and then hoist the flue flap assembled in advance into the flap base, and after the installation and adjustment of the flue flap are completed, the concrete base is poured and fixed, and then the foot bolts of the upper frame of the flue flap are fixed by the method of secondary pouring of concrete.

[0019] After one generation of the coke oven, the flue flap and the base are greatly corroded and damaged, and need to be replaced as a whole, but the flue does not have the shutdown condition due to the above reasons, and personnel cannot enter the flue during replacement, so the flue flap structure needs to be optimized and the installation method needs to be adjusted to meet the requirement of replacing the flue flap and the base as a whole without personnel entering the flue.

[0020] Figure 3 The figure is a schematic view of the modified flue flap structure of the embodiment of the present application. The method for online quick replacement of the flue flap of the coke oven during on-site overhaul of the present application comprises the following steps: (1) The flap base 2 is welded and fixed to the upper structure of the flue flap by adding a 10# channel steel (100x48) frame to form a whole with the flue flap 1; (2) A 50mm gap is reserved between the newly added channel steel frame and the flue flap to ensure the original air leakage rate under the full-closed state of the flue flap; (3) In order to ensure that the modified flue flap can match the size of the original concrete flue, the flue flap blades need to be shortened by 50mm on each side compared with the original flue flap blades, and the total size is shortened from 2100mm to 2000mm; (4) Due to the certain error in the flatness of the flue side wall, a 2mm gap is reserved on each side between the channel steel frame and the original flue wall 3 during the modification of the flue flap, so that the modified flue flap can be smoothly installed; (5) Since the base of the modified flue flap is no longer poured with concrete, in addition to the fixed frame 5 of the flue flap base being fixed by the channel steel frame, a shaft limiting sleeve 4 is additionally arranged near the upper structure of the flue flap to ensure the overall stability of the flue flap structure.

[0021] The installation method of the flue flap in the method for online quick replacement of the flue flap of the coke oven during on-site overhaul of the present application: (1) after the modified flue flap is debugged outside the flue, it is hoisted into the flue as a whole; (2) after the center and elevation of the flue flap are adjusted, heat-resistant concrete is poured into the newly added channel steel frame to increase the structural stability; (3) the foot bolts of the upper frame of the flue flap are fixed by the method of secondary pouring of concrete.

[0022] The coke oven in-situ overhaul flue flap online quick replacement method of the present application has substantial features and significant technical progress, and solves the problem that personnel cannot enter the high-temperature, toxic, and closed limited space of the flue to fix the flue bottom under normal production conditions of the coke oven flue, with the effective fixation of the flue flap base and the flue flap as the breakthrough point.

[0023] The coke oven in-situ overhaul flue flap online quick replacement method of the present application is applied in the in-situ overhaul and reconstruction project of the third phase coke oven of Baosteel, and has remarkable effects. The third phase coke oven of Baosteel is a 4x50-hole carbonization chamber high 6m reheat type top-charging coke oven put into production in 1997, and the overhaul and reconstruction project belongs to online lapping reconstruction. The 6A coke oven and the 5B coke oven share one chimney, and when the 6A coke oven is reconstructed, the 5B coke oven is in normal production state, and the collecting flue and the chimney are in normal operation state. Personnel cannot enter the inside of the flue to replace the damaged flue flap and base. The coke oven in-situ overhaul flue flap online quick replacement method of the present application solves the problem that personnel cannot enter the inside of the flue to fix the flue flap base, and also solves the problem of online whole quick replacement of the flue flap, and reduces the influence on the normal production of the 5B coke oven.

[0024] The above examples are only for illustrating the present application, and are not limited to the present application. Those skilled in the art can make various transformations or changes without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions should belong to the scope of the present application, and should be limited by the claims.

Claims

1. A method for rapid online replacement of flue flaps during in-situ overhaul of a coke oven. Two coke ovens are in the same coke oven group. The exhaust gases generated by the two coke ovens are collected through a collecting flue and discharged into the same chimney. When the 6A coke oven is being renovated, the adjacent 5B coke oven is in normal production and operation. Therefore, the collecting flue and chimney do not meet the conditions for complete shutdown. The following steps are involved: a. Use a channel steel frame to weld and fix the flap base to the upper structure of the flap to form an integral part with the flap; b. A 50mm gap is reserved between the channel steel frame and the flap to ensure the original air leakage rate when the flue flap is fully closed; c. The flap fan blades need to be shortened by 50mm on each side compared to the original flap fan blades, and the total size of the flap is shortened from the original 2100mm to 2000mm; d. Leave a 2mm gap on each side between the channel steel frame and the original flue wall to facilitate the smooth installation of the modified flue flap; e. There is no need to pour concrete on the base of the flue flap. A shaft limiting sleeve is set at the position where the shaft is close to the upper structure of the flap to ensure the overall stability of the flue flap structure.

2. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The size of the channel steel frame is 3445×2196mm.

3. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The channel steel frame is made of 10# channel steel.

4. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The flue flap is fully debugged before being hoisted into the flue, and after installation, heat-resistant concrete is poured into the channel steel frame to enhance structural stability.

5. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The flap upper structure is fixed by anchor bolts and a secondary concrete pouring method.

6. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The rotating shaft limiting sleeve is arranged on the upper structure of the flap near the rotating shaft, and is used to prevent the flap from being laterally displaced or falling off during operation.

7. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The flap is a double-leaf split structure, and the edge of each fan blade is shortened by 50mm to match the size of the flue after modification.

8. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The 2mm gap reserved on each side between the channel steel frame and the flue wall is used to accommodate the structural error of the flue wall and ensure that the flap can be smoothly embedded.

9. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The flap base and the flap upper structure are connected by full welding to form a rigid whole.

10. The method for online rapid replacement of flue flaps during in-situ overhaul of a coke oven according to claim 1, characterized in that: The transformation method is applicable to online splicing and transformation projects in which the common chimney and flue of a coke oven group are in continuous operation and cannot be shut down.

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