Practice of injecting pipes into pipe bricks to eliminate leakage of pipe bricks

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A practical summary of the practice of eliminating pipe brick leakage by inserting pipe bricks and spraying grouting into the pipe bricks in Angang Coking Plant introduces the method of eliminating pipe brick leakage by inserting pipes in pipe bricks and spraying grouting, replacing the traditional basement brick gas duct shotcrete method and the vertical fire channel full grouting method during overhaul. The adoption of this method ensures a normal heating system, which is of certain significance for extending the life of the coke oven. Keywords Inserted tubes in tube bricks, shotcrete method The heating system of the coke oven plays an important role in transporting and regulating heating gas and air to the coke oven and discharging the burned waste gas. Its operation quality is directly related to the implementation of the normal heating system of the coke oven and is an important condition for ensuring stable production and high quality of the coke oven. Since the two 58-type coke ovens in Anyang Iron and Steel Coking Plant are nearly 30 years old, the problem of gas leakage is very serious, which destroys the normal heating system. To solve this problem, we have explored the use of pipe bricks with shotcrete. 1 Problem Analysis The two 58-type coke ovens in Angang Coking Plant are nearly thirty years old. During the long-term production process, the coke oven brick gas ducts have cracked and dislocated due to inconsistent elongation of the upper and lower masonry and temperature stress. These cracks and dislocations are lighter in the middle of the coke oven and become more serious toward the furnace end fire channel. They expand with the increase of furnace age and various furnace body overhauls. As a result, the gas in the brick gas channel leaks into the regenerator, and the brick gas channel of the updraft flows to the brick gas channel of the downdraft. This seriously damages the normal heating system of the coke oven, damages the furnace wall and reduces the quality of coke. In order to solve this problem, the traditional basement brick gas duct gunite method and the vertical fire duct full grouting method during overhaul were used in the past. Since neither of these two methods can make the slurry column vertically penetrate into the gap on the wall of the brick gas duct, the operation is complicated, the pressure is difficult to control, and the effect is not obvious. 2 Proposal and Implementation of the Plan After long-term practice and exploration, we have figured out a method of inserting pipes and spraying into pipe bricks to eliminate leakage of pipe bricks on the basis of gunite grouting in basement brick air ducts, in order to solve this problem. 2.1 Feasibility test In order to verify the feasibility of inserting pipe grouting into pipe bricks, we conducted the following experiments: using Φ15mm galvanized pipe and Φ20mm galvanized pipe (each section is 2000mm long, two pipes are used, which can be longer or shorter according to the actual situation), and the insertion experiment was conducted on 3×28 brick gas ducts (that is, three rows of different combustion chambers). The test shows that all the experimental brick and coal air ducts can be inserted into Φ15mm galvanized pipe or Φ20mm galvanized pipe, which provides the possibility of inserting spray grouting into the brick and coal air duct. 2.2 The implementation of the plan is divided into three steps: the pipe brick inserting spray grouting method. In the first step, divide the Φ15mm galvanized pipe or Φ20mm galvanized pipe into three sections, each with a length of 1500mm. One end of one section is threaded, and the other end is closed into a tapered shape, and the tapered pipe is Use a 6mm drill bit to drill 9 holes in two rows on the circumference, and thread the remaining ends at both ends; in the second step, use one section of galvanized pipe, two sections of galvanized pipe, or three sections of galvanized pipe to connect to the rubber pipe on the shotcrete machine according to the specific location of the leakage; in the third step, implement the spraying operation. During the grouting operation, try to maintain a pressure of 0.2MPa-0.25MPa. When you find that the buried pipe is flowing grout, release the pressure immediately. 2.3 Advantages of the Inserted Tube Gunite Method The tube brick intubated gunite method has five significant advantages over the basement brick gas duct gunite method: 1) The shotcrete position can be changed for different leakage parts, that is, no matter where there is a leak in the brick gas duct, it can be sprayed, and the operation is simple and easy. 2) Because the slurry column is vertically sprayed onto the wall of the pipe brick and directly injected into the crack of the pipe brick, unlike the traditional gunite method where the slurry flows on the pipe wall and penetrates into the crack, the slurry injected into the crack will not fall off even after the mud is dry or the brick gas channel is poked, ensuring the shotcrete effect and improving the quality of daily maintenance of the coke oven. 3) Pressure is relatively easy to control. This kind of gunite method is not like the traditional gunite method where the pressure is too high and it is easy to spray into the vertical fire channel, and the pressure is too low and the leakage cannot be sprayed. It only needs to control the pressure at 0.2MPa~0.25MPa. 4) This shotcrete method saves about half of the spray material than the traditional shotcrete method, reducing costs. 5) This shotcrete method only requires two people to operate, which is one less person than the traditional shotcrete method, saving manpower. 3 Effect Analysis By comparing before and after using the inner tube shotcrete method, we can see two obvious effects after use. 1) The changes in the number of fire passes after using this shotcrete method are shown in Table 1. 2) Before using the gunite method, there were 5 fire channels in the No. 1 furnace due to the leakage of the brick gas channel, causing the fire channel temperature to be below 700°C. The temperature changes of these 5 fire channels after using the gunite method are shown in Table 2. As can be seen from Table 1 and Table 2, the use of the in-tube brick shotcrete method fundamentally solves the problem of brick gas channel leakage, protects the furnace wall, ensures a stable heating system, thereby ensuring the stable production and high quality of the coke oven, and is of great significance to extending the life of the coke oven. This post was last edited by Lawless on 2009-3-28 15:21 ]