Construction method of catalytic cracking unit external heat exchanger cylinder lining

Abstract

The application discloses a construction method of a lining of a cylinder of an external heat exchanger of a catalytic cracking device, and is specifically implemented according to the following steps: welding an omega-shaped anchoring nail on a carbon steel wall of the external heat exchanger and performing knocking inspection on the welded omega-shaped anchoring nail; installing a special steel formwork in the carbon steel wall of the external heat exchanger, the distance between the outer wall of the special steel formwork and the inner wall of the carbon steel wall being the thickness of the lining to be constructed; pouring the lining material between the special steel formwork and the carbon steel wall; after pouring is completed, when the surface temperature of the carbon steel wall and the special steel formwork rises to a target temperature, spraying water on the outer wall of the carbon steel wall to reduce the temperature of the poured lining, and removing the formwork when the strength of the poured lining reaches 70% of the design strength, and after the formwork is removed, the lining is maintained; after the maintenance is completed, the lining is subjected to oven treatment, and the construction is completed. The lining constructed by the method is smooth in surface, small in deviation at a connecting joint and eliminates the construction joint in the prior construction method.

Description

Technical Field

[0001] This invention belongs to the field of refining and chemical equipment lining casting technology, and relates to the construction method of the outer heat exchanger shell lining of catalytic cracking unit. Background Technology

[0002] During long-term operation, the external heat exchanger of a catalytic cracking unit in an oil refining plant is prone to lining detachment and cracking due to wear from the high-temperature catalyst and leakage from the steam-water tubes. Without the protection of the lining, the high temperature inside the external heat exchanger can easily cause high-temperature creep in the carbon steel wall, reducing its strength. Once a leak occurs, the high-temperature, high-speed mixture of catalyst and flue gas can erode the sand holes in the wall, creating large-diameter leaks, which in severe cases can cause production fluctuations or even shutdown of the unit.

[0003] Prior to this invention, the original construction process, according to the technical specifications for catalytic converter linings, required the construction of the external heat exchanger lining with welded Ω-shaped anchors to employ a vertical construction method involving formwork support, vibration, and integral casting. This formwork scheme involved prefabricating standard wooden templates based on the cylinder dimensions and covering the formed templates with a smooth sheet metal. Due to the low strength of the wooden templates, to prevent the unformed lining from collapsing during casting, one layer of wooden templates was used, and after vibrating and casting the lining, the next layer of wooden templates was installed and the lining was cast. This traditional lining casting method resulted in increased thickness deviations at the joints between adjacent wooden templates due to manual splicing and the curvature of the equipment. If the casting time of the next layer of lining exceeded two hours from the previous layer, a construction joint had to be made on the outer side of the previous layer, increasing the lining construction time. Furthermore, poor bonding between the upper and lower lining layers at the construction joint could easily lead to thermal cracking after construction began. Summary of the Invention The purpose of this invention is to provide a construction method for the lining of the external heat exchanger shell of a catalytic cracking unit. The lining surface after construction is smooth and the deviation at the joint is small, eliminating the construction joints in the existing construction methods.

[0004] The technical solution adopted in this invention is a construction method for the lining of the external heat exchanger shell of a catalytic cracking unit, which is implemented according to the following steps: Step 1: Weld the Ω-shaped anchor bolts to the carbon steel wall of the external heat exchanger and tap the welded Ω-shaped anchor bolts for inspection. Step 2: Install a special steel template inside the carbon steel wall of the external heat exchanger. The distance between the outer wall of the special steel template and the inner wall of the carbon steel wall is the thickness of the lining to be constructed. Step 3: Pour the lining material between the special steel template and the carbon steel wall; Step 4: After the casting is completed, when the surface temperature of the carbon steel vessel wall and the special steel template rises to the target temperature, water is sprayed onto the outer wall of the carbon steel vessel wall to lower the temperature of the cast lining. When the strength of the cast lining reaches 70% of the design strength, the formwork is removed and the lining is cured after removal. Step 5: After curing, the lining is oven-dried to complete the construction.

[0005] The invention is further characterized in that, In step 1, the tapping inspection process is as follows: every 4m 2 One Ω-shaped anchor is randomly selected for inspection. Each Ω-shaped anchor is tapped with a 0.5kg hammer. The Ω-shaped anchor is bent at 90°. If it does not break, it is qualified and a new Ω-shaped anchor is welded next to it. If it breaks, it is unqualified and a new Ω-shaped anchor is welded to the original position.

[0006] In step 2, the special steel formwork includes several first steel structure formwork and second steel structure formwork spaced apart along the axial direction of the carbon steel vessel wall. Each first steel structure formwork includes several first templates and second templates spaced apart along the circumferential direction of the carbon steel vessel wall. Each second steel structure formwork includes several second templates arranged sequentially along the circumferential direction of the carbon steel vessel wall. Each second template includes a second body, and each side of the second body is provided with a second connecting plate. Each second connecting plate is perpendicular to the second body, and each second connecting plate is provided with a plurality of second connecting holes. Each second connecting plate is located on the concave side of the second body. Each first template includes a first body, and each edge of the first body is provided with a second connecting plate. Each second connecting plate is perpendicular to the second body and is provided with a plurality of second connecting holes. Each second connecting plate is located on the concave side of the second body. The first body is provided with a pouring hole, and the edge of the pouring hole is provided with a first connecting plate. The first connecting plate is provided with a plurality of first connecting holes and is perpendicular to the second body. A sealing plate is provided inside the pouring hole.

[0007] The sealing plate includes a baffle, and a third connecting plate is provided at the edge of the baffle. The third connecting plate is provided with several third connecting holes. The third connecting plate is perpendicular to the baffle. The shape of the baffle is consistent with the pouring hole. The several third connecting holes are provided one-to-one with several first connecting holes.

[0008] The concave side of the second body is provided with several longitudinal stiffening plates and transverse stiffening plates.

[0009] The pouring holes in the first steel structure formwork of two adjacent layers are staggered.

[0010] The specific process of step 2 is as follows: According to the inner wall shape of the carbon steel vessel wall, install the second steel structure template and the first steel structure template layer by layer from bottom to top inside the carbon steel vessel wall. Adjacent first steel structure templates and second steel structure templates are connected by bolts in the second connection holes. This process is repeated to complete the installation of the special mold. A layer of lubricating oil is then applied to the outer wall of the special mold. The adjacent first templates and second templates in each first steel structure template are connected by bolts installed in the second connection holes, and the adjacent second templates in each second steel structure template are connected by bolts installed in the second connection holes.

[0011] The specific process of step 3 is as follows: the lining material is poured through the bottom pouring hole into the space between the special steel template and the carbon steel wall. After the pouring of this layer is completed, all the pouring holes of this layer are sealed with a sealing plate. Then the lining material is poured through the pouring hole of the next layer, and so on, until the pouring of the entire lining is completed. The pouring process for each layer of pouring holes is as follows: pouring is carried out in a clockwise or counterclockwise order for all pouring holes of the layer. The pouring height of each pouring hole shall not exceed 300mm. After each pouring hole is poured, it shall be vibrated with a vibrator. After the vibration is completed, the next pouring hole shall be poured. During vibration, the vibrator is inserted into the poured lining material through the pouring hole to a depth of 50mm~100mm and vibrated for 30s. The distance the vibrator moves each time is no greater than the distance between two adjacent Ω-shaped anchors in the circumferential direction.

[0012] In step 4, the target temperature is 60℃~80℃, and the temperature is reduced to 20℃~35℃; The maintenance process is as follows: first, use mist curing for 24 hours, then use natural curing for 48 hours.

[0013] In step 5, the oven drying process is as follows: the temperature is raised from the ambient temperature to 110℃ and held for 12 hours, then raised to 350℃ and held for 24 hours, and finally cooled to the ambient temperature. The heating time from natural temperature to 110℃ is 24 hours, the heating time from 110℃ to 350℃ is 12 hours, and the cooling time from 350℃ to natural temperature is 24 hours.

[0014] The beneficial effects of this invention are: (1) The thickness deviation at the joint of the lining obtained by the construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention is less than 2mm, the surface is free of pitting and honeycomb phenomenon, and there are pores. The pores with a depth greater than 10mm and a diameter greater than 8mm are no more than 20 / m², and the area of ​​the pitted surface of the small pores with a depth less than 8mm and a diameter less than 20mm is less than 20% of the total area. When the lining surface is gently tapped with a 0.5Kg iron hammer, the sound is solid and crisp, without hollow sound. (2) The construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention adopts steel structure template, supports the formwork once and pours continuously, which improves the construction speed of pouring and vibration, and avoids the problem of installing thin aluminum plates on traditional wooden formwork, thereby improving efficiency and reducing construction joints.

[0015] (3) After demolding, the heat insulation and wear-resistant lining cylinder and the upper and lower inclined tubes of this invention have a beautiful streamlined appearance and smooth surface. They do not need to be modified, which improves the construction speed, enhances the quality of the project, and makes up for the shortcomings of standard steel templates. The shape of the lining after construction is completely consistent with the shape of the vessel wall, which is more conducive to the flow of catalyst, reduces friction, and extends the service life of the equipment under the protection of the heat insulation and wear-resistant layer. Attached Figure Description

[0016] Figure 1 This is a partial plan view of the special mold used in the construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention. Figure 2 This is a schematic diagram of the structure of the second template in the construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention; Figure 3 This is a schematic diagram of the structure of the first template in the construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention; Figure 4 This is a schematic diagram of the structure of the sealing plate in the construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention; Figure 5 This is a schematic diagram of the structure of the top screw and internal threaded sleeve in the construction method of the external heat exchanger shell lining of the catalytic cracking unit of the present invention.

[0017] In the diagram, 1. First steel structure formwork, 2. Second steel structure formwork, 3. First formwork, 4. Second formwork, 5. Second body, 6. Second connecting plate, 7. Second connecting hole, 8. Longitudinal stiffening plate, 9. Transverse stiffening plate, 10. First body, 11. Pouring hole, 12. First connecting plate, 13. First connecting hole, 14. Baffle, 15. Third connecting plate, 16. Third connecting hole, 17. Top screw, 18. Internal threaded sleeve, 19. Vertical column. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0019] Example 1 The construction method for the external heat exchanger shell lining of the catalytic cracking unit of the present invention is implemented according to the following steps: Step 1: Weld the Ω-shaped anchor bolts to the carbon steel wall of the external heat exchanger and tap the welded Ω-shaped anchor bolts for inspection. Step 2: Install a special steel template inside the carbon steel wall of the external heat exchanger. The distance between the outer wall of the special steel template and the inner wall of the carbon steel wall is the thickness of the lining to be constructed. Step 3: Pour the lining material between the special steel template and the carbon steel wall; Step 4: After the casting is completed, when the surface temperature of the carbon steel vessel wall and the special steel template rises to the target temperature, water is sprayed onto the outer wall of the carbon steel vessel wall to lower the temperature of the cast lining. When the strength of the cast lining reaches 70% of the design strength, the formwork is removed and the lining is cured after removal. Step 5: After curing, the lining is oven-dried to complete the construction.

[0020] Example 2 Based on Example 1, in step 1, the tapping inspection process is as follows: every 4m 2 One Ω-shaped anchor is randomly selected for inspection. Each Ω-shaped anchor is tapped with a 0.5kg hammer. The Ω-shaped anchor is bent at 90°. If it does not break, it is qualified and a new Ω-shaped anchor is welded next to it. If it breaks, it is unqualified and a new Ω-shaped anchor is welded to the original position.

[0021] Example 3 Based on Example 2, such as Figure 1 As shown, the special steel formwork includes several first steel structure formwork 1 and second steel structure formwork 2 arranged at intervals along the axial direction of the carbon steel vessel wall. Each first steel structure formwork 1 includes several first formwork 3 and second formwork 4 arranged at intervals along the circumferential direction of the carbon steel vessel wall. Each second steel structure formwork 2 includes several second formwork 4 arranged sequentially along the circumferential direction of the carbon steel vessel wall. like Figure 2 As shown, each second template 4 includes a second body 5, and each side of the second body 5 is provided with a second connecting plate 6. Each second connecting plate 6 is perpendicular to the second body 5. Each second connecting plate 6 is provided with a plurality of second connecting holes 7. Each second connecting plate 6 is located on the concave side of the second body 5. like Figure 3As shown, each first template 3 includes a first body 10. A second connecting plate 6 is provided on each side of the first body 10. Each second connecting plate 6 is perpendicular to the second body 5. Each second connecting plate 6 has several second connecting holes 7. Each second connecting plate 6 is located on the concave side of the second body 5. A pouring hole 11 is provided on the first body 10. A first connecting plate 12 is provided on the edge of the pouring hole 11. A several first connecting holes 13 are provided on the first connecting plate 12. The first connecting plate 12 is perpendicular to the second body 5. A sealing plate is provided inside the pouring hole 11. The sealing plate includes a baffle 14. A third connecting plate 15 is provided on the edge of the baffle 14. A several third connecting holes 16 are provided on the third connecting plate 15. The third connecting plate 15 is perpendicular to the baffle 14. The shape of the baffle 14 is consistent with that of the pouring hole 11. The several third connecting holes 16 correspond one-to-one with the several first connecting holes 13.

[0022] Example 4 Based on Example 3, the specific process of step 3 is as follows: the lining material is poured through the bottom pouring hole 11 into the space between the special steel template and the carbon steel wall. After the pouring of this layer is completed, all the pouring holes 11 of this layer are sealed with a sealing plate. Then the lining material is poured through the pouring hole 11 of the next layer, and so on, until the pouring of the entire lining is completed. The pouring process for each layer of pouring holes 11 is as follows: all pouring holes 11 in the layer are poured in a clockwise or counterclockwise order, the pouring height of each pouring hole 11 does not exceed 300mm, and each pouring hole 11 is vibrated with a vibrator after pouring. After the vibration is completed, the next pouring hole 11 is poured. During vibration, the vibrator is inserted through the pouring hole 11 into the poured lining material to a depth of 50mm~100mm and vibrated for 30s. The distance the vibrator moves each time is no greater than the distance between two adjacent Ω-shaped anchors in the circumferential direction.

[0023] Example 5 Based on Example 4, in step 4, the target temperature is 60℃~80℃, and the temperature is reduced to 20℃~35℃; The maintenance process is as follows: first, use mist curing for 24 hours, then use natural curing for 48 hours.

[0024] Example 6 This invention provides a construction method for the lining of the external heat exchanger shell of a catalytic cracking unit, specifically implemented according to the following steps: Step 1: Weld Ω-shaped anchors to the carbon steel wall of the external heat exchanger according to the requirements of the "Technical Specification for Thermal Insulation and Wear-Resistant Lining". The welded parts should be free of defects such as cracks, incomplete penetration and undercut. The distance between two adjacent Ω-shaped anchors should be at least 50mm. In special diameter change parts, the installation density of Ω-shaped anchors should be appropriately increased. After welding, the Ω-shaped anchors should be tapped for inspection. The tapping inspection process is as follows: every 4m 2 One Ω-shaped anchor is randomly selected for inspection. Each Ω-shaped anchor is tapped with a 0.5kg hammer. The Ω-shaped anchor is bent at 90°. If it does not break, it is qualified and a new Ω-shaped anchor is welded next to it. If it breaks, it is unqualified and a new Ω-shaped anchor is welded to the original position. Step 2: Install a special steel template inside the carbon steel wall of the external heat exchanger. The distance between the outer wall of the special steel template and the inner wall of the carbon steel wall is the thickness of the lining to be constructed. That is, the shape of the special steel template is consistent with the internal shape of the carbon steel wall, so as to ensure that the thickness of the lining to be constructed is the same at all locations. Among them, such as Figure 1 As shown, the special steel formwork includes several first steel structure formwork 1 and second steel structure formwork 2 arranged at intervals along the axial direction of the carbon steel vessel wall. Each first steel structure formwork 1 includes several first formwork 3 and second formwork 4 arranged at intervals along the circumferential direction of the carbon steel vessel wall. Each second steel structure formwork 2 includes several second formwork 4 arranged sequentially along the circumferential direction of the carbon steel vessel wall. like Figure 2 As shown, each second template 4 includes a second body 5, and each side of the second body 5 is provided with a second connecting plate 6. Each second connecting plate 6 is perpendicular to the second body 5. Each second connecting plate 6 is provided with a plurality of second connecting holes 7. Each second connecting plate 6 is provided on the concave side of the second body 5. The concave side of the second body 5 is provided with a plurality of longitudinal stiffening plates 8 and transverse stiffening plates 9 to improve the strength of the second template 4. like Figure 3 As shown, each first template 3 includes a first body 10, and each side of the first body 10 is provided with a second connecting plate 6. Each second connecting plate 6 is perpendicular to the second body 5. Each second connecting plate 6 is provided with a plurality of second connecting holes 7. Each second connecting plate 6 is provided on the concave side of the second body 5. The first body 10 is provided with a pouring hole 11. The edge of the pouring hole 11 is provided with a first connecting plate 12. The first connecting plate 12 is provided with a plurality of first connecting holes 13. The first connecting plate 12 is perpendicular to the second body 5. A sealing plate is provided inside the pouring hole 11. The pouring holes 11 in the first steel structure formwork 1 of two adjacent layers are staggered; In each of the first steel structure templates 1, bolts are inserted into the corresponding second connecting holes 7 of adjacent first templates 3 and second templates 4, and the threaded end of the bolts is connected to a nut, thereby connecting the first templates 3 and the second templates 4. Bolts are inserted into the corresponding second connection holes 7 of adjacent second templates 4 in each second steel structure template 2, and nuts are connected to the threaded end of the bolts, thereby connecting the first template 3 and the second template 4. Similarly, the adjacent first steel structure template 1 and second steel structure template 2 are also equipped with bolts inserted into the corresponding second connection holes 7, and the threaded end of the bolt is connected to a nut. That is, all the first templates 3 and second templates 4 are equipped with bolts inserted into the corresponding second connection holes 7, and the threaded end of the bolt is connected to a nut. like Figure 4 As shown, the sealing plate includes a baffle 14, and a third connecting plate 15 is provided at the edge of the baffle 14. The third connecting plate 15 is provided with a plurality of third connecting holes 16. The third connecting plate 15 is perpendicular to the baffle 14. The shape of the baffle 14 is consistent with that of the pouring hole 11. The plurality of third connecting holes 16 are provided in a one-to-one correspondence with a plurality of first connecting holes 13. Each third connecting hole 16 and its corresponding first connecting hole 13 are provided with a bolt. The threaded end of the bolt is connected to a nut, thereby connecting the sealing plate to the pouring hole 11 and realizing the sealing of the pouring hole 11. Each pouring hole 11 has a height of 400mm and a width of 300mm, and each first template 3 and second template 4 has a height of 600mm. Step 2 is as follows: Based on the inner wall shape of the carbon steel vessel, the second steel structure template 2 and the first steel structure template 1 are installed layer by layer from bottom to top inside the carbon steel vessel. Adjacent first steel structure templates 1 and second steel structure templates 2 are connected by bolts installed in the second connecting holes 7. Figure 5 As shown, the concave side of each second steel structure template 2 and each first steel structure template 1 is connected to one end of the top screw 17, and the other end of each top screw 17 is threadedly connected to the internal thread sleeve 18. The end of each internal thread sleeve 18 away from the top screw 17 is welded to the outer wall of the riser column 19. The riser column 19 is set at the center of the carbon steel wall. This process is repeated to complete the installation of the special mold. A layer of lubricating oil is applied to the outer wall of the special mold to prevent concrete from sticking to the steel structure template during demolding. The second steel structure formwork 2 and the first steel structure formwork 1 are supported by a set of top screws, internal threaded sleeves and vertical columns to prevent deformation and improve stability and accuracy. In each of the first steel structure templates 1, adjacent first templates 3 and second templates 4 are connected by bolts installed in the second connecting holes 7, and in each of the second steel structure templates 2, adjacent second templates 4 are connected by bolts installed in the second connecting holes 7; and the joints between all the first templates 3 and second templates 4 are aligned to prevent misalignment and pitting of the lining after pouring, which would affect the quality of the lining. Step 3: Pour the lining material between the special steel template and the carbon steel wall; The specific process is as follows: the lining material is poured through the bottom pouring hole 11 into the space between the special steel template and the carbon steel vessel wall. After the pouring of this layer is completed, all the pouring holes 11 of this layer are sealed with a sealing plate. Then the lining material is poured through the pouring hole 11 of the next layer, and so on, until the pouring of the entire lining is completed. The pouring process for each layer of pouring holes 11 is as follows: all pouring holes 11 in the layer are poured in a clockwise or counterclockwise order, the pouring height of each pouring hole 11 does not exceed 300mm, and each pouring hole 11 is vibrated with a vibrator after pouring. After the vibration is completed, the next pouring hole 11 is poured. During vibration, the vibrator is inserted into the poured lining material through the pouring hole 11 to a depth of 50mm~100mm and vibrated for 30s to ensure sufficient vibration and overflow of air bubbles. The goal is to make the surface of the poured lining have slurry that does not sink. The distance the vibrator moves each time should not be greater than the distance between two adjacent Ω-shaped anchors in the circumferential direction. Step 4: After casting is completed, when the surface temperature of the carbon steel vessel wall and the special steel template rises to 60℃~80℃, spray water on the outer wall of the carbon steel vessel wall to reduce the temperature of the cast lining to 20℃~35℃. When the strength of the cast lining reaches 70% of the design strength, demold. When demolding, be careful not to damage the lining surface and prevent strong impacts that may cause chipping or breakage. After demolding, the lining should be first mist-cured for 24 hours and then naturally cured for 48 hours. Step 5: After curing, the lining is oven-dried to allow it to expand evenly, slowly and fully, while evaporating the moisture it contains. This prevents damage to the lining due to concentrated thermal stress after the equipment is put into operation, thus completing the construction. The oven drying process is as follows: the temperature is raised from the natural temperature to 110℃ and held for 12 hours, then raised to 350℃ and held for 24 hours, and finally cooled to the natural temperature. The heating time from natural temperature to 110℃ is 24 hours, the heating time from 110℃ to 350℃ is 12 hours, and the cooling time from 350℃ to natural temperature is 24 hours.

[0025] During the oven drying process, a thermal imager was used to measure the temperature at a constant temperature of 350℃. The temperature of the two cylinders was found to be uniform, with the highest temperature being about 130℃. No cracks wider than 2mm or through-type network cracks were found on the lining surface.

Claims

1. A method for constructing the lining of the external heat exchanger shell of a catalytic cracking unit, characterized in that, The specific steps are as follows: Step 1: Weld the Ω-shaped anchor bolts to the carbon steel wall of the external heat exchanger and tap the welded Ω-shaped anchor bolts for inspection. Step 2: Install a special steel template inside the carbon steel wall of the external heat exchanger. The distance between the outer wall of the special steel template and the inner wall of the carbon steel wall is the thickness of the lining to be constructed. Step 3: Pour the lining material between the special steel template and the carbon steel wall; Step 4: After the casting is completed, when the surface temperature of the carbon steel vessel wall and the special steel template rises to the target temperature, water is sprayed onto the outer wall of the carbon steel vessel wall to lower the temperature of the cast lining. When the strength of the cast lining reaches 70% of the design strength, the formwork is removed and the lining is cured after removal. Step 5: After curing, the lining is oven-dried to complete the construction.

2. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 1, characterized in that, In step 1, the tapping inspection process is as follows: every 4m 2 One Ω-shaped anchor is randomly selected for inspection. Each Ω-shaped anchor is tapped with a 0.5kg hammer. The Ω-shaped anchor is bent at 90°. If it does not break, it is qualified and a new Ω-shaped anchor is welded next to it. If it breaks, it is unqualified and a new Ω-shaped anchor is welded to the original position.

3. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 1, characterized in that, In step 2, the special steel template includes a number of first steel structure templates (1) and second steel structure templates (2) spaced apart along the axial direction of the carbon steel vessel wall. Each first steel structure template (1) includes a number of first templates (3) and second templates (4) spaced apart along the circumferential direction of the carbon steel vessel wall. Each second steel structure template (2) includes a number of second templates (4) arranged sequentially along the circumferential direction of the carbon steel vessel wall. Each of the second templates (4) includes a second body (5), and each side of the second body (5) is provided with a second connecting plate (6). Each of the second connecting plates (6) is perpendicular to the second body (5). Each of the second connecting plates (6) is provided with a plurality of second connecting holes (7). Each of the second connecting plates (6) is located on the concave side of the second body (5). Each of the first templates (3) includes a first body (10), and each side of the first body (10) is provided with a second connecting plate (6). Each second connecting plate (6) is perpendicular to the second body (5). Each second connecting plate (6) is provided with a plurality of second connecting holes (7). Each second connecting plate (6) is provided on the concave side of the second body (5). The first body (10) is provided with a pouring hole (11). The edge of the pouring hole (11) is provided with a first connecting plate (12). The first connecting plate (12) is provided with a plurality of first connecting holes (13). The first connecting plate (12) is perpendicular to the second body (5). A sealing plate is provided inside the pouring hole (11).

4. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 3, characterized in that, The sealing plate includes a baffle (14), and a third connecting plate (15) is provided at the edge of the baffle (14). The third connecting plate (15) is provided with a plurality of third connecting holes (16). The third connecting plate (15) is perpendicular to the baffle (14). The shape of the baffle (14) is consistent with that of the pouring hole (11). The plurality of third connecting holes (16) are provided in correspondence with the plurality of first connecting holes (13).

5. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 3, characterized in that, The concave side of the second body (5) is provided with several longitudinal stiffening plates (8) and transverse stiffening plates (9).

6. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 3, characterized in that, The pouring holes (11) in the first steel structure formwork (1) of the two adjacent layers are staggered.

7. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 4, characterized in that, The specific process of step 2 is as follows: According to the inner wall shape of the carbon steel vessel wall, install the second steel structure template (2) and the first steel structure template (1) layer by layer from bottom to top inside the carbon steel vessel wall. The adjacent first steel structure template (1) and second steel structure template (2) are connected by bolts in the second connecting hole (7). This process is repeated to complete the installation of the special mold. A layer of lubricating oil is applied to the outer wall of the special mold. In each of the first steel structure templates (1), the adjacent first templates (3) and second templates (4) are connected by bolts installed in the second connecting holes (7), and in each of the second steel structure templates (2), the adjacent second templates (4) are connected by bolts installed in the second connecting holes (7).

8. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 3, characterized in that, The specific process of step 3 is as follows: the lining material is poured through the bottom pouring hole (11) into the space between the special steel template and the carbon steel wall. After the layer is poured, all the pouring holes (11) of the layer are sealed with a sealing plate. Then the lining material is poured through the pouring hole (11) of the next layer. This process is repeated until the entire lining is poured. The pouring process of each layer of pouring holes (11) is as follows: all pouring holes (11) of the layer are poured in a clockwise or counterclockwise order. The pouring height of each pouring hole (11) shall not exceed 300mm. After each pouring hole (11) is poured, it shall be vibrated with a vibrator. After the vibration is completed, the next pouring hole (11) shall be poured. During vibration, the vibrator is inserted through the pouring hole (11) into the poured lining material to a depth of 50mm~100mm and vibrated for 30s. The distance the vibrator moves each time is no greater than the distance between two adjacent Ω-shaped anchors in the circumferential direction.

9. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 8, characterized in that, In step 4, the target temperature is 60℃~80℃, and the temperature is reduced to 20℃~35℃; The maintenance process is as follows: first, use mist curing for 24 hours, then use natural curing for 48 hours.

10. The construction method for the lining of the external heat exchanger shell of the catalytic cracking unit according to claim 9, characterized in that, In step 5, the oven drying process is as follows: the temperature is raised from the ambient temperature to 110℃ and held for 12 hours, then raised to 350℃ and held for 24 hours, and finally cooled to the ambient temperature. The heating time from natural temperature to 110℃ is 24 hours, the heating time from 110℃ to 350℃ is 12 hours, and the cooling time from 350℃ to natural temperature is 24 hours.

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