Thermal shock resistant heat recovery coke oven gas collecting pipe

Abstract

The utility model discloses a thermal shock resistant heat recovery coke oven gas collecting pipe which comprises a gas collecting pipe shell, and a gas collecting pipe heat preservation layer, a lower pipe circumference heat insulation layer and a lower pipe circumference surface heat layer are sequentially arranged on the lower half circumference of the inner wall of the gas collecting pipe shell from outside to inside. The upper half circumference of the inner wall of the gas collecting pipe shell is sequentially provided with a gas collecting pipe heat preservation layer, an upper pipe circumference heat insulation layer, a heat spreader and an upper pipe circumference heat layer from outside to inside, and a gas collecting pipe cavity is defined by the upper pipe circumference heat layer and the lower pipe circumference heat layer; the soaking device comprises a soaking device shell, a shell cavity of the soaking device shell is filled with metallic tin, and the filling rate of the metallic tin in the shell cavity ranges from 92% to 95%. The thickness of the upper pipe peripheral heat insulation layer is greater than that of the upper pipe peripheral surface heat layer; the thickness of the lower pipe circumferential surface heat layer is larger than that of the lower pipe circumferential heat insulation layer. Soaking rib plates are fixedly arranged on two side plates of the soaking device shell and are positioned in a shell cavity of the soaking device shell. The gas collecting pipe can effectively eliminate thermal stress generated by temperature imbalance, and ensures safe and reliable conveying of high-temperature waste heat.

Description

Technical Field

[0001] The utility model relates to a clean heat recovery coke oven, in particular to a structural improvement of a gas collecting pipe for conveying high-temperature waste heat flue gas of the coke oven in a clean heat recovery coke oven system. Background Art

[0002] Most of the existing gas pipelines of heat recovery coke ovens are made of steel shells lined with refractory insulation materials. Since the gas collecting pipes transport high-temperature and rapid flue gas, the temperature of the exhaust gas transported by the gas collecting pipes is above 1000°C, even up to 13000°C, and the exhaust gas contains harmful corrosive gases such as water vapor, SO2, and CO. Regardless of whether aluminum silicate ceramic fiber templates or thermal insulation castables are used for tamping and pouring, the thermal insulation lining is very likely to shrink or fall off, resulting in cracks and gaps, and has poor resistance to turbulent erosion, aggravating the erosion of the thermal insulation lining and even the steel pipe by harmful high-temperature exhaust gas, seriously affecting the service life and thermal insulation performance of the gas collecting pipes, reducing the temperature of the flue gas entering the waste heat power generation boiler, and preventing the waste heat of the coke oven from being efficiently utilized.

[0003] What has a greater impact is the large temperature difference between the inside and outside of the gas collecting pipe wall. The gas collecting pipe has to withstand a large temperature gradient and the resulting internal temperature stress. Most coke oven gas collecting pipes adopt a circular tube structure. Since the high-temperature exhaust gas rises upward, the flames generated by the secondary combustion in the raw coal gas pipe also burn upward. Therefore, the upper wall of the gas collecting pipe is more likely to cause more obvious thermal stress due to temperature fluctuations. In fact, the upper wall of the gas collecting pipe is more likely to crack or loosen between bricks, which will lead to the falling of bricks on the upper wall of the gas collecting pipe and the collapse of the wall. After multiple monitoring and analysis of temperature data and thermal stress values, the applicant found that the uneven temperature of each masonry block of the pipe wall is an important factor in increasing the destructive effect of thermal stress. Utility Model Content

[0004] In view of the above problems existing in the prior art, the technical problem to be solved by the utility model is to provide a thermal shock resistant heat recovery coke oven gas collecting pipe which can effectively eliminate the thermal stress caused by temperature imbalance.

[0005] In order to solve the above technical problems, the utility model discloses a thermal shock resistant heat recovery coke oven gas collecting pipe, comprising a gas collecting pipe outer shell in the shape of a circular tube, wherein the lower half of the inner wall of the gas collecting pipe outer shell is composed of a gas collecting pipe insulation layer, a lower tube peripheral insulation layer and a lower tube peripheral surface heat layer from the outside to the inside, and the upper half of the inner wall of the gas collecting pipe outer shell is composed of a gas collecting pipe insulation layer, an upper tube peripheral insulation layer, a heat spreader and an upper tube peripheral surface heat layer from the outside to the inside, wherein the upper tube peripheral surface heat layer and the lower tube peripheral surface heat layer form a gas collecting pipe cavity; the heat spreader comprises a heat spreader shell, and the shell cavity of the heat spreader shell is filled with metallic tin, and the filling rate of the metallic tin in the shell cavity is 92%-95%.

[0006] After adopting the above structure, since the inner wall of the gas collecting tube shell is provided with a heat preservation layer, a heat insulating layer and a surface heat layer with multiple layers having good heat preservation and heat insulation effects, a high heat resistance structure is formed, which effectively reduces the heat dissipation of the high-temperature exhaust gas of the gas collecting tube, greatly reduces the surface temperature of the gas collecting tube, not only ensures the full utilization of the heat energy of the high-temperature exhaust gas of the coke oven, but also improves the operating environment and prolongs the service life of the gas collecting tube; laying a shell wall cushion layer on the shell wall of the tube shell not only further enhances the heat insulation effect, but also makes the laying surface of the tube wall flat, which is conducive to the laying of refractory heat insulation bricks. The upper tube peripheral surface heat layer and the lower tube peripheral surface heat layer surround the gas collecting tube cavity, forming a surface heat insulation layer built with surface heat refractory bricks. The surface heat insulation layer of refractory bricks greatly enhances the mechanical strength and thermal shock resistance of the gas collecting tube, avoids the damage to the surface heat layer caused by cracks and gaps caused by rapid cooling and heating and mechanical impact, and improves the heat preservation and heat insulation effect and prolongs the service life. Moreover, since a heat spreader is arranged between the heat insulation layer around the gas collecting pipe and the heat layer around the upper pipe, with the help of the good thermal conductivity and heat storage performance of the heat spreader, on the one hand, the good thermal conductivity can effectively balance the temperature of different areas of the pipe wall, reduce the temperature difference between the pipe wall areas, and thus reduce the thermal stress caused by thermal expansion and contraction; on the other hand, the heat storage effect of the heat spreader can well ensure the consistency of the pipe wall temperature and greatly reduce the temperature fluctuation of the pipe wall. The heat spreader shell is filled with metal tin, which has a low melting point (231.89℃) and a high boiling point (2260℃). The melting point is just lower than the temperature of the gas conveying airflow in the gas collecting pipe, and its boiling point is higher than the temperature of the conveying airflow in the gas collecting pipe; at the same time, the metal tin also has the characteristics of high thermal conductivity, which can quickly transfer heat to the shell and the gas collecting pipe wall. The flowing liquid metal tin can even out the heat, which not only effectively suppresses the temperature fluctuation of the gas collecting pipe, but also balances the temperature difference of each part of the pipe wall, and has a good effect of resisting thermal stress.

[0007] In a preferred embodiment of the utility model, the surface heating surface of the upper tube peripheral heat layer and the surface heating surface of the lower tube peripheral heat layer are located on the same cylindrical surface. The thickness of the upper tube peripheral heat insulation layer is greater than the thickness of the upper tube peripheral heat layer; the thickness of the lower tube peripheral heat layer is greater than the thickness of the lower tube peripheral heat insulation layer. The upper and lower tube walls of the tube periphery adopt different structures, so that the thermal insulation effect is better and the structure is more reasonable.

[0008] In a preferred embodiment of the utility model, heat-equalizing ribs are fixedly arranged on the two side plates of the heat spreader shell, and the heat-equalizing ribs are located in the shell cavity of the heat spreader shell. The heat-equalizing ribs on the two side plates of the heat spreader shell are arranged alternately. The heat spreader shell and the heat-equalizing ribs are made of high-temperature resistant stainless steel. It has better transmission and balance of unstable temperature fluctuations and temperature differences, and can effectively eliminate thermal stress caused by temperature imbalance.

[0009] Furthermore, the gas collecting pipe shell is rolled from carbon steel plate, and the gas collecting pipe insulation layer is laid from ceramic fiber felt; the lower tube peripheral insulation layer and the upper tube peripheral insulation layer are built from mullite insulation bricks, and the lower tube peripheral surface thermal layer and the upper tube peripheral surface thermal layer are built from corrosion-resistant mullite refractory bricks. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The thermal shock resistant heat recovery coke oven gas collecting pipe of the utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0011] Figure 1 It is a schematic cross-sectional structure diagram of a specific implementation of the utility model thermal shock resistant heat recovery coke oven gas collecting pipe;

[0012] Figure 2 yes Figure 1 The cross-sectional structure diagram of the middle heat spreader;

[0013] Figure 3 yes Figure 2 Left view of

[0014] Figure 4 yes Figure 2 A-A section enlarged structure diagram.

[0015] In the figure, 1 is the outer shell of the gas collecting pipe; 2 is the heat preservation layer of the gas collecting pipe; 3 is the heat insulation layer around the lower tube; 4 is the heat layer around the lower tube; 5 is the heat insulation layer around the upper tube; 6 is the heat spreader; 7 is the heat layer around the upper tube; 8 is the shell of the heat spreader; 9 is the metal tin; 10 is the heat spreader rib. DETAILED DESCRIPTION

[0016] like Figure 1 The thermal shock resistant heat recovery coke oven gas collecting pipe shown in the figure comprises a gas collecting pipe shell 1, which is a cylindrical tube shell made of rolled carbon steel plate, and a gas collecting pipe insulation layer 2 is laid on the inner wall of the gas collecting pipe shell 1, and the gas collecting pipe insulation layer 2 is made of ceramic fiber felt laid along the inner wall of the gas collecting pipe shell 1. Different masonry structures are used for the upper half of the pipe and the lower half of the pipe on the gas collecting pipe insulation layer 2.

[0017] The lower half of the inner wall of the gas collecting tube shell 1 is provided with the gas collecting tube insulation layer 2, the lower tube peripheral insulation layer 3 and the lower tube peripheral surface heat layer 4 from the outside to the inside. The lower tube peripheral insulation layer 3 is built with mullite insulation bricks with plug-in tenons and tenons, and the lower tube peripheral surface heat layer 4 is built with anti-corrosion mullite refractory bricks with plug-in tenons and tenons. The thickness of the lower tube peripheral surface heat layer 4 is greater than that of the lower tube peripheral insulation layer 3, which can produce a better heat uniformity effect.

[0018] The upper half of the inner wall of the gas collecting tube shell 1 is provided with the gas collecting tube insulation layer 2, the upper tube peripheral insulation layer 5, the heat spreader 6 and the upper tube peripheral thermal layer 7 from the outside to the inside. The upper tube peripheral insulation layer 5 is built with mullite insulation bricks with plug-in tenons and tenons, and the upper tube peripheral thermal layer 7 is built with anti-corrosion mullite refractory bricks with plug-in tenons and tenons. The thickness of the upper tube peripheral insulation layer 5 is greater than that of the upper tube peripheral thermal layer 7, which can produce better fire resistance and anti-corrosion effects.

[0019] The surface heating surface of the upper tube peripheral heat layer 7 and the surface heating surface of the lower tube peripheral heat layer 4 are located on the same cylindrical surface, so that the upper tube peripheral heat layer 7 and the lower tube peripheral heat layer 4 surround the gas collecting pipe cavity.

[0020] like Figure 2 , Figure 3 and Figure 4 As shown, the heat spreader 6 adopts a tile-like structure with a quarter cylindrical surface and is symmetrically arranged on both sides of the vertical axis of the gas collecting pipe. Each heat spreader 6 includes a heat spreader shell 8, which is a closed box cavity structure with a quarter arc cross-section. The heat spreader shell 8 is welded from high-temperature resistant stainless steel plates. The shell cavity of the heat spreader shell 8 is filled with metal tin 9, and the filling rate of the metal tin 9 in the shell cavity is 92%-95%. The filling rate is equal to the ratio of the volume of the metal tin 9 to the actual volume of the shell cavity of the heat spreader shell 8 at room temperature.

[0021] A plurality of heat absorbing ribs 10 are fixedly welded in the shell cavity of the heat spreader shell 8. The heat absorbing ribs 10 are welded to the plate surfaces of the two side plates respectively, and the heat absorbing ribs 9 on the two side plates are arranged alternately. A certain gap is left between the plate end of the heat absorbing rib 9 on one side plate surface and the plate surface on the other side, so that the molten metal tin can flow in the shell cavity of the heat spreader shell 8.

[0022] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principle and practical application of the utility model, so that technicians in the relevant technical field can understand and use the utility model well. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the utility model.

Claims

1. A thermal shock resistant heat recovery coke oven gas collecting pipe, comprising a gas collecting pipe shell (1) in the shape of a circular tube, characterized in that: The lower half of the inner wall of the gas collecting pipe shell (1) comprises, from outside to inside, a gas collecting pipe insulation layer (2), a lower tube peripheral insulation layer (3) and a lower tube peripheral surface thermal layer (4); the upper half of the inner wall of the gas collecting pipe shell (1) comprises, from outside to inside, a gas collecting pipe insulation layer (2), an upper tube peripheral insulation layer (5), a heat spreader (6) and an upper tube peripheral surface thermal layer (7); the upper tube peripheral surface thermal layer (7) and the lower tube peripheral surface thermal layer (4) form a gas collecting pipe cavity; the heat spreader (6) comprises a heat spreader shell (8); the shell cavity of the heat spreader shell (8) is filled with metal tin (9); the filling rate of the metal tin (9) in the shell cavity is 92%-95%.

2. The thermal shock resistant heat recovery coke oven gas collecting pipe according to claim 1, characterized in that: The surface heating surface of the upper tube peripheral surface heating layer (7) and the surface heating surface of the lower tube peripheral surface heating layer (4) are located on the same cylindrical surface.

3. The thermal shock resistant heat recovery coke oven gas collecting pipe according to claim 1, characterized in that: The thickness of the upper tube peripheral heat insulation layer (5) is greater than the thickness of the upper tube peripheral surface heat layer (7); the thickness of the lower tube peripheral surface heat layer (4) is greater than the thickness of the lower tube peripheral heat insulation layer (3).

4. The thermal shock resistant heat recovery coke oven gas collecting pipe according to claim 1, 2 or 3, characterized in that: Heat-spreading ribs (10) are fixedly arranged on the two side plates of the heat spreader shell (8), and the heat-spreading ribs (10) are located in the shell cavity of the heat spreader shell (8).

5. The thermal shock resistant heat recovery coke oven gas collecting pipe according to claim 4, characterized in that: The heat equalizing ribs (10) located on the two side plates of the heat equalizer shell (8) are arranged in a staggered manner.

6. The thermal shock resistant heat recovery coke oven gas collecting pipe according to claim 4, characterized in that: The heat spreader shell (8) and the heat spreader ribs (10) are made of high temperature resistant stainless steel.

7. The thermal shock resistant heat recovery coke oven gas collecting pipe according to claim 1, characterized in that: The gas collecting pipe shell (1) is formed by rolling carbon steel plates, and the gas collecting pipe insulation layer (2) is formed by laying ceramic fiber felt; the lower tube peripheral insulation layer (3) and the upper tube peripheral insulation layer (5) are formed by laying mullite insulation bricks, and the lower tube peripheral surface thermal layer (4) and the upper tube peripheral surface thermal layer (7) are formed by laying erosion-resistant mullite refractory bricks.

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