Dry quenching coke tank bottom gate capable of prolonging service life and preparation method thereof

Abstract

A bottom gate for dry quenching coke ovens that can improve service life is mainly composed of two identical semi-circular bottom gate plates. Each bottom gate plate consists of a bottom gate shell, a heat insulation layer, an outer ring liner, a middle ring liner, an inner ring liner, an edge baffle, a first gap, a second gap, a grout layer, screw holes and slots on each liner, and bolts. The outer ring liner is made of silicon carbide ceramic, while the middle and inner ring liners are made of mullite silicon carbide. The width of the first gap is not less than 5 mm, and the width of the second gap is not less than 1 mm. The grout is made of refractory ramming material. There are shoulders inside the screw holes. There is a fixing plate on the bottom gate shell below the corner of the four adjacent liner plates, and an anti-oxidation coating is applied to the fixing plate and the edge baffle. Preparation method: First, connect the high-temperature resistant alloy baffle coated with anti-oxidation paint to the bottom gate shell; place a partition with a thickness of not less than 1mm at two gaps; lay each ring and each lining plate through the slots, and connect them to the bottom gate bottom plate with bolts; grout; dry.

Description

Technical Field

[0001] This invention relates to the field of equipment for coking production, specifically to a dry quenching coke tank bottom gate and its preparation method. Background Technology

[0002] The rotary coke oven mainly consists of the oven body, lining plates, lifting rods, transmission rods, annular octagonal beams, guide wheel assemblies, bottom gate, buffer seat, refractory materials, and lubrication pipelines. Since the coke oven lining plates are in direct contact with red-hot coke, the material must possess strong heat resistance and wear resistance, high strength and toughness under hot conditions, and the ability to withstand alternating hot and cold temperatures. Currently, the bottom gate lining plates are made of heat-resistant cast steel ZG35Cr24Ni7SiN and heat-resistant stainless steel 20X23H18, which, while possessing good wear resistance and heat resistance and capable of short-term heat resistance up to 1100℃, are susceptible to damage during prolonged use due to the impact, abrasion, and rapid heating and cooling of coke. This damage can lead to the lining plates burning, deforming, warping, detaching, or developing phase defects. Lightweight castables are not wear-resistant. It cannot meet the application requirements under the condition of bottom gate; after the bottom gate is damaged, coke will directly impact the bottom gate support plate, which can easily cause hot coke to escape, burn the electrical circuit of the coke tanker, and cause accidents such as fire.

[0003] Search results:

[0004] Chinese patent application CN202010270638.2 discloses a "Method for Overheating Casting of Energy-Saving Coke Tanks," which involves adding a refractory lining casting space to the bottom gate of the coke tank; welding butterfly-shaped anchoring nails to the inner wall of the coke tank; attaching low-thermal-conductivity polymer-bonded nano-insulation boards to the inner surface of the coke tank; and then painting it twice with asphalt paint. Formwork is then erected, with the bottom gate and lower cone section cast first. After casting and curing, the inclined cone section is then cast, followed by the straight section casting. After completion, natural curing and baking are performed. This method addresses the shortcomings of traditional coke tank construction methods. The shell temperature is too high, the frame is prone to cracking and deformation, and the inner lining plate is prone to oxidation, cracking, deformation, wear and fall off due to high temperature, resulting in frequent replacement of the lining plate. However, there are also problems such as high moisture content of the castable, limited space on the bottom gate, thinness, poor resistance to rapid cooling and heating of the castable itself, and the difference in expansion coefficient between the butterfly-shaped anchors and the castable. The bottom gate is used 30-70 times a day, and its lifespan is generally 3-6 months or even longer. The abnormal expansion of the anchors causes cracking and peeling of the castable, especially in the bottom gate area, where the damage is very serious.

[0005] A paper published in the journal *Refractory Materials* [2017, 51(1): 63-64] introduces the application of lightweight refractory castables in the lining of coke cans for dry quenching coke ovens. It describes how, in order to reduce the material procurement and maintenance costs of coke can linings, improve the insulation performance and heat recovery rate of coke cans, and reduce equipment failures in dry quenching coke ovens, the paper explores the effect of using lightweight refractory castables to replace alloy liners as coke can linings, and analyzes the reasons for choosing high-strength mullite lightweight castables and high-strength lightweight castables as lining materials for the lower conical and straight sections of the coke can, respectively. Practice has proven that lightweight refractory castables have good insulation effects as linings, reducing the surface temperature of the outer wall of the can from 500℃ to 150℃, greatly reducing the heat loss from red-hot coke and the damage to the can body and surrounding components caused by high temperatures. It also solves the problem of lining plates falling into the dry quenching coke oven and blocking the rotary sealing valve, eliminating safety hazards and demonstrating significant economic benefits. However, the problem is that lightweight castables have low strength, poor wear resistance, are not resistant to rapid cooling and heating, and are prone to peeling and breakage.

[0006] Chinese patent publication CN110668832A discloses a wear-resistant castable for coke ovens with the following composition: ≤5mm bauxite: 30-68 parts; ≤3mm alumina hollow spheres: 10-45 parts; alumina micro powder: 1-5 parts; silica micro powder: 5-12 parts; pure calcium aluminate cement: 3-10 parts; dispersant: 0.1-1 parts; explosion retardant: 0.1-1 parts; tartaric acid: 0.02-0.03 parts. While this wear-resistant castable for coke ovens possesses good compressive strength, flexural strength, and wear resistance, its problem lies in the poor rapid cooling and heating performance of the bauxite-containing castable, making it prone to cracking and unsuitable for thin-layer bottom gates.

[0007] Chinese Patent Publication No. CN109704792A discloses a castable refractory for coke oven linings, comprising, by weight percentage: 10%–22% high-alumina bauxite with a particle size of 5 mm–8 mm; 20%–38% calcium hexaaluminate with a particle size of 3 mm–5 mm; 6%–10% calcined quartz with a particle size of 1 mm–3 mm; 11%–21% magnesium olivine with a particle size less than or equal to 1 mm; 9%–19% magnesium aluminum spinel with a particle size of 180 mesh; 2%–7% ethyl silicate; 2%–10% hydrated alumina with a particle size less than 0.088 mm; 1%–4% dextrin; and 1%–3% water-reducing agent. This invention also discloses a method for manufacturing coke oven linings. The problem is the same as that of Chinese Patent Publication No. CN110668832A, namely, the castable with bauxite has poor rapid cooling and heating performance, is prone to cracking, and is not suitable for use in thin-layer bottom gates.

[0008] The high thermal shock resistant and wear-resistant preform for dry-quenched coke cans described in Chinese Patent CN110294623A is made from the following raw materials in parts by weight: 20-30 parts silicon carbide crystals; 40-60 parts bauxite-based homogeneous material; 5-10 parts silica micro powder; 1-3 parts water; 0.2-0.6 parts water-reducing agent; 15-20 parts α-Al₂O₃ powder; and 8-12 parts MoSi₂ powder. The silicon carbide whiskers have a diameter of 0.1-2 μm and a length of 20-300 μm, and are in powder form. The bauxite-based homogeneous material contains 88 wt% alumina. The preform is made by firing bauxite green ore with 75 wt% alumina content at 1500-1600℃ for 4 hours, resulting in a bulk density of 2.92-3.43 g·cm³. -3 The high thermal shock resistant and wear-resistant prefabricated parts for dry-quenched coke cans use silicon carbide whiskers, bauxite-based homogeneous materials, and silica micropowder as base materials, and are coated with α-Al2O3 and MoSi2 powders on the surface. The resulting products are resistant to high temperatures, corrosion, wear, and thermal shock, and have excellent resistance to rapid cooling and heating. The problem is similar to that of Chinese patent publications CN110668832A and CN109704792A.

[0009] Chinese Patent Publication No. CN212316016U describes a quick-installation, wear-resistant composite coke can liner and a dry quenching coke can. The liner consists of a support plate and a wear-resistant composite layer. The support plate is located outside the wear-resistant composite layer, and its outer side is equipped with a liner fixing mechanism to secure the liner to the dry quenching coke can. The can body is equipped with straight ribs and reinforcing rings, which are arranged circumferentially around the can body. The straight ribs and reinforcing rings intersect to form multiple frames. The liner fixing mechanism includes a locking device, a locking hook frame, a movable locking hook, and a lower locking plate. The liner is installed on the corresponding frame, and the locking hook frame and movable locking hook are interlocked. The lower locking plate extends downward from the liner and is limited and supported on the reinforcing ring. Its advantages include high temperature resistance, wear resistance, and low thermal conductivity, making it less prone to burn-out. However, the problem lies in the fact that the thickness of the coke can bottom gate is only 20mm in some areas and 60-80mm in others. If straight ribs and reinforcing rings are installed, they cannot provide adequate protection, making the gate susceptible to burn-out. Summary of the Invention

[0010] This invention aims to overcome the shortcomings of existing technologies and provide a dry quenching coke oven bottom gate liner that solves the problems of rapid heat transfer and easy burn-off of the liner plate by using a high-strength composite ceramic liner plate as the load-bearing liner plate of the cylinder circumference, a high-temperature resistant alloy baffle plate of the bowstring part, and ceramic liner plates in other parts, with rammed material for grouting. It also extends the replacement cycle of the coke oven bottom gate liner plate from 1-3 months to more than 6 months, reduces the surface temperature of the bottom gate by more than 150°C, and reduces the cost by 30-50%. This invention is not easy to fall off and can improve the service life of the dry quenching coke oven bottom gate liner.

[0011] Measures to achieve the above objectives:

[0012] A bottom gate for dry quenching coke ovens that can improve service life is mainly composed of two identical semi-circular bottom gate plates. Each bottom gate plate consists of a bottom gate shell, a heat insulation layer on the bottom gate shell, an outer ring liner, a middle ring liner, and an inner ring liner on the heat insulation layer, edge baffles at the joints of the two semi-circular bottom gate plates, gaps between the liner plates and between different ring liners, a grout layer in the gap between two adjacent baffles, screw holes and slots on each liner plate, and bolts in the screw holes. The outer ring liner is made of silicon carbide ceramic, and its silicon carbide content is not less than 90 wt%; the middle ring liner and the inner ring liner... The ring lining plates are all made of mullite-silicon carbide, with a silicon carbide content of 3-15 wt%. The width of gap one is not less than 5 mm, and the width of gap two is not less than 1 mm. The grout is made of refractory ramming material. A shoulder is provided in the screw holes on each lining plate. The diameter of the screw hole above the upper end face of the shoulder is at least 2 mm larger than the bolt diameter, and the diameter of the remaining screw holes is the same as the bolt diameter. A fixing plate is provided on the bottom gate shell below the corner of the four adjacent lining plates through the heat insulation layer. The fixing plate forms a fixing plate ring, and an anti-oxidation coating is applied to the fixing plate and the edge baffle. The edge baffle is a high-temperature alloy that can withstand temperatures of not less than 1100℃.

[0013] Furthermore, the height of the screw holes above the upper end face of the shoulder accounts for 30-50% of the thickness of each of the aforementioned lining plates.

[0014] Furthermore, the physical properties of the silicon carbide ceramic outer ring liner are as follows: the fire resistance temperature is not less than 1100℃, and the number of water cooling cycles at 1100℃ is not less than 100 times, and its compressive strength is not less than 100MPa.

[0015] Physical properties of mullite silicon carbide middle ring liner and mullite silicon carbide inner ring liner: refractory temperature not lower than 1100℃, and water cooling cycle at 1100℃ not less than 100 times, and compressive strength not lower than 80MPa.

[0016] Furthermore, the raw material composition and weight percentage content of the refractory ramming material used in the grouting layer are as follows: mullite: 55-75%; aluminum powder: 1-7%; iron oxide powder: 5-15%; silicon carbide powder: 3-15%; sodium tetraborate powder: 0.5-5%; aluminum dihydrogen phosphate solution: 2.5-15%; wherein the weight percentage of mullite particles with a size of 3-1mm is not less than 45%.

[0017] Further: The composition and weight percentage of the coating material for the anti-oxidation coating are as follows: sodium silicate: 15-45%; sodium borate: 3-12%; sodium bentonite: 1-5%; silicon carbide powder: 45-75%; and water is added at a weight percentage of 8-20% of the total weight of the above raw materials.

[0018] Further: A reinforcing grout is applied to the grout layer to form a reinforcing grout layer.

[0019] Furthermore: the strong grout layer is made by adding aluminum dihydrogen phosphate solution to the refractory ramming mix, and the amount added is such that it becomes a paste that can be easily applied.

[0020] A method for preparing a dry quenching coke pot bottom gate that can improve its service life, comprising the following steps:

[0021] 1) First, the two semi-circular bottom gates coated with anti-oxidation paint are spliced ​​together using slots and then connected to the bottom gate shell with bolts;

[0022] 2) Place partitions with a thickness of not less than 1 mm at two points in the gaps between the high-temperature alloy baffles;

[0023] 3) The silicon carbide ceramic outer ring liner, the silicon carbide mullite middle ring liner, and the silicon carbide mullite inner ring liner are laid through the slots respectively. Each ring and each liner is connected to the bottom plate of the bottom gate with bolts.

[0024] 4) Perform grouting by placing the prepared refractory ramming compound grout into each gap and tamping it down to form a grout layer.

[0025] 5) Dry the product. After natural drying for 12 to 48 hours, bake it at a temperature not exceeding 350℃ for at least 12 hours before putting it into use.

[0026] Furthermore: A reinforcing grout layer is applied over the grout layer, with a thickness not exceeding 1 mm.

[0027] The role and mechanism of each raw material and main process in this invention

[0028] The reason why the outer ring liner of this invention is made of silicon carbide ceramic material with a silicon carbide content of not less than 90 wt%, an operating temperature of not less than 1100℃, and a water cooling cycle of not less than 100 times at 1100℃, and a pressure resistance of not less than 100 MPa, is because silicon carbide ceramic material has high strength and good toughness, can withstand the pressure of the cylindrical coke tank shell, and is not easy to break; at the same time, it has good resistance to thermal damage and wear resistance.

[0029] The reason why the material of the middle ring liner and the inner ring liner of this invention is that both are made of mullite silicon carbide, with a silicon carbide content of 3 to 15 wt%, and an operating temperature of not less than 1100℃, and a water cooling cycle of not less than 100 times at 1100℃, and a pressure resistance of not less than 80 MPa, is because mullite silicon carbide ceramic material has high strength, good oxidation resistance, and can resist oxidation during the cold air intake process when the bottom gate is opened. It also has excellent heat damage resistance and wear resistance.

[0030] The reason why the width of gap one is controlled to be no less than 5mm and the width of gap two to be no less than 1mm, and the grout is made of refractory ramming material, is that both silicon carbide ceramics and mullite silicon carbide ceramics have oxidation expansion. Therefore, a certain expansion gap needs to be left. The width of gap one is no less than 5mm, and the grout is made of refractory ramming material to absorb the expansion of the lining plate to prevent it from being squeezed and cracked. The width of gap two is no less than 1mm to absorb the expansion of the high-temperature alloy baffle.

[0031] The reason why this invention provides a shoulder at 30-50% of the thickness of each liner plate within the screw holes of the silicon carbide ceramic liner plate and the mullite silicon carbide liner plate, with the screw hole diameter above the upper end face of the shoulder being at least 2mm larger than the bolt diameter and the remaining screw hole diameter being the same as the bolt diameter, is that providing a shoulder at 30-50% of the thickness of each liner plate helps to increase the thickness of the ceramic that blocks the nut, thus preventing the bolt from breaking during use; it also helps to fix the bolt, preventing it from falling out of the screw hole. Furthermore, because the screw hole diameter above the upper end face of the shoulder is at least 2mm larger than the bolt diameter, the fired ceramic has high strength and can fix the ceramic liner plate.

[0032] The reason why this invention requires the edge baffle to be a high-temperature alloy that can withstand temperatures of not less than 1100°C is that the high-temperature alloy comes into direct contact with hot coke, which can improve its durability at high temperatures.

[0033] The reason why this invention provides a fixing plate on the bottom gate shell below the corner of the four adjacent liner plates, forming a fixing ring, and is coated with an anti-oxidation coating, is that ceramic liners may crack, break, or even fall off during long-term use. Since the number of fixing bolts is limited, providing a fixing plate on the coke tank shell below the corner of the four adjacent liner plates, forming a fixing ring, can prevent the liner from falling off after breakage, allowing it to continue to be used. Even if it falls off, it will be in small pieces and will not block the coke discharge valve. The anti-oxidation coating on the fixing plate prevents high-temperature oxidation and extends its service life.

[0034] The reason why this invention applies a reinforcing grout containing aluminum dihydrogen phosphate solution to the refractory ramming compound grout layer in gaps one and two is that the surface of the refractory ramming compound is not very smooth, and its strength generally requires a certain temperature to reach a high level, and it will not reach the surface of the ceramic lining. By applying a refractory ramming compound grout containing aluminum dihydrogen phosphate solution to the refractory ramming compound grout, its fluidity is increased, and it becomes like a paint, which can increase the adhesion between the lining and the grout. The sealing performance will also be improved after high-temperature use.

[0035] Compared with the prior art, this invention solves the problems of rapid heat transfer and easy burn-off of the bottom gate liner of the coke tank by using high-strength composite ceramic liner as the load-bearing liner of the cylinder circumference, high-temperature alloy baffle, and ceramic liner in other parts, and ramming material for grouting. It also extends the replacement cycle of the bottom gate liner of the coke tank from 1-3 months to more than 6 months, reduces the surface temperature of the bottom gate by more than 150°C, and reduces the cost by 30-50%. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the bottom gate of the dry quenching coke tank according to the present invention;

[0037] Figure 2 for Figure 1 A schematic diagram of the screw holes on each of the inner lining plates;

[0038] Figure 3 for Figure 1 Schematic diagram of the middle fixing plate;

[0039] In the diagram: 1—Bottom gate shell, 2—Insulation layer, 3—Outer ring liner, 4—Middle ring liner, 5—Inner ring liner, 6—Edge baffle, 7—Gap one, 8—Gap two, 9—Grouting layer, 10—Screw hole, 11—Slot, 12—Bolt, 13—Shoulder, 14—Fixing plate, 15—Anti-oxidation coating, 16—Reinforcing grout layer. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings:

[0041] Table 1 is a list of the raw material composition and content of the grout in various embodiments of the present invention;

[0042] Table 2 is a list of the raw material composition and content of the anti-oxidation coatings and grouting agents in various embodiments of the present invention;

[0043] Table 3 is a list of test results used in various embodiments of the present invention.

[0044] A bottom gate for dry quenching coke ovens that can improve service life is mainly composed of two identical semi-circular bottom gates. Each bottom gate base plate consists of a bottom gate shell 1, a heat insulation layer 2 on the bottom gate shell 1, an outer ring liner 3, a middle ring liner 4, and an inner ring liner 5 on the heat insulation layer 2, an edge baffle 6 at the joint between the two semi-circular bottom gate base plates, a gap 1 7 between each liner and between different ring liners, a grout layer 9 in the gap 2 8 between two adjacent baffles 6, screw holes 10 and slots 11 on each liner, and bolts 12 in the screw holes 10. The outer ring liner 3 is made of silicon carbide ceramic, and its silicon carbide content is not less than 90 wt%; the middle ring liner 4 and the inner ring liner 5 are both made of mullite carbide. It is made of silicon, and its silicon carbide content is 3-15 wt%; the width of gap 1 7 is not less than 5 mm, and the width of gap 2 8 is not less than 1 mm; the grout is made of refractory ramming material; a shoulder 13 is machined in the screw hole 10 on each liner plate, and the diameter of the screw hole 10 above the upper end face of the shoulder 13 is greater than the bolt diameter by 2 mm / 2.3 mm / 2.6 mm / 2.8 mm / 3.1 mm, and the diameter of the remaining screw hole 10 is the same as the diameter of the bolt 12; a fixing plate 14 is welded to the bottom gate shell 1 through the heat insulation layer 2 below the corner of the four adjacent liner plates, and a fixing plate ring is formed on the semi-circular bottom gate bottom plate; an anti-oxidation coating 15 is applied to the fixing plate 14; the edge baffle 6 is a high temperature alloy that can withstand temperatures not less than 1100℃.

[0045] The height of the screw hole 9 above the upper end face of the shoulder 13 accounts for 30% / 39% / 49% / 35% / 44% of the thickness of each of the above-mentioned lining plates.

[0046] The physical properties of the silicon carbide ceramic outer ring liner 3 are as follows: the operating temperature is 1112℃, the number of water cooling cycles at 1112℃ is more than 106, and the pressure resistance is more than 113MPa.

[0047] The physical properties of the mullite-silicon carbide middle ring liner 4 and the mullite-silicon carbide inner ring liner 5 are as follows: the fire resistance temperature is 1110℃, and the number of water cooling cycles at 1110℃ is more than 108 times. Their compressive strength is more than 87MPa.

[0048] A reinforcing grout is applied to the grout layer 9 to form a reinforcing grout layer 16.

[0049] The strong grout layer 16 is made by adding aluminum dihydrogen phosphate solution to the refractory ramming mix, with the amount added being such that it becomes a paste that can be easily applied.

[0050] The dry quenching coke pot bottom gate of the present invention is prepared according to the following steps:

[0051] 1) First, the two semi-circular bottom gates coated with anti-oxidation paint are spliced ​​together using slots and then connected to the bottom gate shell with bolts;

[0052] 2) Place paper or plastic partitions with a thickness of not less than 1 mm at two points in the gaps between the high-temperature alloy baffles;

[0053] 3) The silicon carbide ceramic outer ring liner, the mullite silicon carbide middle ring liner, and the mullite silicon carbide inner ring liner are laid through the slots respectively. Each ring and each liner is connected to the bottom plate of the bottom gate with bolts.

[0054] 4) Perform grouting by placing the prepared refractory ramming compound grout into each gap and tamping it down to form a grout layer.

[0055] 5) Dry the product. After natural drying for any time within 12–48 hours, then dry it at temperatures of 287℃ / 312℃ / 296℃.

[0056] Baking at 329℃ / 346℃ for 12.3h / 13.8h / 14h / 13.5h / 12.8h, then put into use.

[0057] Table 1. List of raw material composition and content (wt%) of the grouting agents in various embodiments of the present invention.

[0058]

[0059]

[0060] Table 2. List of raw material composition and content (wt%) of the anti-oxidation coatings and grouting agents of various embodiments of the present invention.

[0061]

[0062] Note: In the examples of refractory ramming compound with aluminum dihydrogen phosphate solution in Table 2, the raw material ratios of the refractory ramming compound are the same as those in Table 1.

[0063] Table 3 List of test results used in various embodiments of the present invention

[0064]

[0065] The results in Table 3 show that by using high-strength composite ceramic liners, the problems of rapid heat transfer and easy burn-off of the bottom gate liner of the coke tank can be solved. The replacement cycle of the bottom gate liner of the coke tank can be extended from 1-3 months to more than 6 months. The surface temperature of the bottom gate can be reduced by more than 150°C, and the cost can be reduced by 30-50%. This is conducive to reducing production costs, improving economic efficiency, and improving the working environment.

[0066] This specific embodiment is merely a best example and is not intended to limit the implementation of the technical solution of the present invention.

Claims

1. A bottom gate for a dry quenching coke tank that can improve its service life, mainly composed of two identical semi-circular bottom gates; each bottom gate consists of a bottom gate shell, a heat insulation layer on the bottom gate shell, an outer ring liner, a middle ring liner, and an inner ring liner on the heat insulation layer, an edge baffle at the joint between the two semi-circular bottom gate plates, gaps between the liners in the outer ring liner and the liners in the middle ring liner, and between different ring liners, a grout layer in the gap between two adjacent baffles, and screw holes and slots are provided on each liner of the outer ring liner, the middle ring liner, and the inner ring liner, with bolts installed in the screw holes, characterized in that: The outer ring liner is made of silicon carbide ceramic with a silicon carbide content of not less than 90 wt%; the middle and inner ring liners are made of mullite silicon carbide with a silicon carbide content of 3-15 wt%; the width of gap one is not less than 5 mm, and the width of gap two is not less than 1 mm; the grout is made of refractory ramming material; a shoulder is provided in the screw holes on each of the outer, middle, and inner ring liners; the diameter of the screw hole above the upper end face of the shoulder is at least 2 mm larger than the bolt diameter, and the diameter of the remaining screw holes is the same as the bolt diameter; a fixing plate is provided on the bottom gate shell below the corner of the four adjacent liners of the outer and middle ring liners, through the heat insulation layer, the fixing plate forming a fixing plate ring, and an anti-oxidation coating is applied to the fixing plate and the edge baffle; the edge baffle is a high-temperature alloy resistant to not less than 1100℃; The bottom gate lining includes an outer ring lining, a middle ring lining, and an inner ring lining. The outer ring lining and the middle ring lining are composed of multiple linings spliced ​​together.

2. The dry quenching coke pot bottom gate as described in claim 1, characterized in that: The height of the screw holes above the upper end face of the shoulder on each of the outer ring liner, middle ring liner, and inner ring liner accounts for 30 to 50% of the thickness of each liner.

3. The dry quenching coke pot bottom gate as described in claim 1, characterized in that: The physical properties of the silicon carbide ceramic outer ring liner are as follows: the operating temperature is not lower than 1100℃, the number of water cooling cycles at 1100℃ is not lower than 100, and its pressure resistance is not lower than 100MPa. Physical properties of silicon carbide mullite middle ring liner and silicon carbide mullite inner ring liner: refractory temperature not less than 1100℃, and water cooling cycle at 1100℃ not less than 100 times, and compressive strength not less than 80MPa.

4. The dry quenching coke pot bottom gate as described in claim 1, characterized in that: The raw material composition and weight percentage of the refractory ramming mix used in the grouting layer are as follows: mullite: 55-75%; aluminum powder: 1-7%; iron oxide powder: 5-15%; silicon carbide powder: 3-15%; sodium tetraborate powder: 0.5-5%; aluminum dihydrogen phosphate solution: 2.5-15%; wherein the weight percentage of mullite particles with a size of 3-1mm is not less than 45%.

5. The dry quenching coke pot bottom gate as described in claim 1, characterized in that: The coating for the anti-oxidation coating has the following composition and weight percentage content: sodium silicate: 15-45%; sodium borate: 3-12%; sodium bentonite: 1-5%; silicon carbide powder: 45-75%; and water is added at 8-20% of the total weight percentage of the above raw materials.

6. The dry quenching coke pot bottom gate as described in claim 1, characterized in that: A reinforced grout layer is formed by applying a reinforcing grout layer onto the grout layer.

7. The dry quenching coke pot bottom gate as described in claim 6, characterized in that: The reinforcing grout is made by adding aluminum dihydrogen phosphate solution to the refractory ramming mix, with the amount added being sufficient to form a paste that can be easily applied.

8. The method for preparing a dry quenching coke pot bottom gate that can improve the service life as described in claim 1, comprising the following steps: 1) First, the two semi-circular bottom gates coated with anti-oxidation paint are spliced ​​together using slots and then connected to the bottom gate shell with bolts; 2) Place partitions with a thickness of not less than 1 mm at two points in the gaps between the high-temperature alloy baffles; 3) The silicon carbide ceramic outer ring liner, silicon carbide mullite middle ring liner, and silicon carbide mullite inner ring liner are laid through the slots, and each liner is connected to the bottom plate of the bottom gate with bolts. 4) Perform grouting by placing the prepared refractory ramming compound grout into each gap and tamping it down to form a grout layer. 5) Dry the product. After natural drying for 12 to 48 hours, bake it at a temperature not exceeding 350℃ for at least 12 hours before putting it into use.

9. The method for preparing a dry quenching coke pot bottom gate that can improve the service life as described in claim 8, characterized in that: A reinforcing grout layer is applied over the grout layer, with a thickness not exceeding 1 mm.

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