Quickly-constructed double-pipe column heat insulation structure of steel rolling heating furnace and preparation method thereof

Abstract

The application discloses a double-water-pipe stand column heat insulation structure of a steel rolling heating furnace which can be rapidly constructed, and comprises, from outside to inside, an infrared high-emissivity thermal barrier coating, a lightweight high-strength mullite prefabricated part layer, a thermal expansion fastening compensation layer, a refractory fiber blanket layer, a nano microporous heat insulation plate layer, an aerogel heat insulation coating and double-water-pipe steel pipes, and a preparation method thereof comprises the following steps: after the refractory fiber blanket layer is fixed by using a heat preservation layer compaction fixed mold for compaction and fixation, the lightweight high-strength mullite prefabricated part layer is constructed. The application is optimized and designed based on different use temperature intervals, improves the stand column heat insulation performance and high-temperature use performance, and through the combined design of the mortise and tenon structure and the thermal expansion self-locking structure, the anchor fastening and the metal fixing block are cancelled, the problems of material thermal expansion mismatch, stress concentration damage and heat island effect caused by the anchor fastening and the metal fixing block are eliminated, the overall stand column heat insulation performance is improved, the heating furnace energy consumption is reduced, the service life of the stand column heat insulation lining is prolonged, the construction time is shortened, and the furnace bottom radiation heat transfer is strengthened.

Description

Technical Field

[0001] This invention relates to the field of energy-saving technology for heating furnaces, specifically to a rapidly constructible double-water-pipe column heat insulation structure for steel rolling heating furnaces and its preparation method. Background Technology

[0002] The steel rolling heating furnace is a crucial energy and thermal equipment in a hot rolling production line, playing a vital role in steel rolling production. Its fuel consumption accounts for over 80% of the total energy consumption of the hot rolling process. Of the furnace's energy losses, the heat loss from water cooling in the water beams and columns, which utilize vaporization cooling, accounts for 25-35% of the total energy loss. Taking a hot rolling heating furnace with an annual output of 2 million tons as an example, the heat dissipation loss from the furnace body and the water cooling loss in the water beams consumes approximately 5,000 tons of standard coal equivalent annually, which is a major reason for the high heat loss of the heating furnace. Therefore, improving the thermal insulation performance of the water beam and column insulation structures is crucial to reducing heat loss caused by cooling water.

[0003] In existing technologies, most water beam and column insulation structures employ a double-layer composite structure, with an inner layer of 20mm thick refractory fiber blanket and an outer layer of 60mm thick self-flowing castable. This structure suffers from poor thermal shock stability and a service life typically of only 2-3 years, sometimes requiring localized repairs after a very short period. Furthermore, the self-flowing castable has a high thermal conductivity (1.2W / m·K, hot surface temperature 1000℃) and poor insulation performance, which is a major reason for the high water-cooling heat loss in water beams and columns. In addition, the performance of the self-flowing castable in water beams and columns is significantly affected by construction factors, requiring long curing and baking times, often impacting production due to extended maintenance cycles. Some companies have attempted to replace the double-layer composite structure composed of castable and ceramic fiber blanket with a single ceramic fiber module, reducing heat loss by 38%. However, the Al2O3-SiO2 ceramic fiber module has low strength and cannot resist the corrosion of iron oxide scale, requiring furnace shutdown for maintenance and repair every six months, thus failing to achieve widespread application in actual production.

[0004] Chinese patent CN103388055B discloses a refractory insulation lining structure for the furnace beams and columns of a walking beam furnace for heating high-temperature oriented silicon steel. The structure includes metal pipes forming the foundation of the furnace beams or columns. Heat-resistant pads are spaced along the axial direction on the metal pipes forming the foundation. Metal anchors are evenly distributed along the axial and circumferential directions on the outer wall of the metal pipes. A refractory insulation layer, integrated with the metal anchors, is cast tightly against the outer wall of the metal pipes. An anti-slag adhesion layer and an anti-oxidation coating are then sequentially applied to the outside of the refractory insulation layer. This invention's refractory insulation lining for the furnace beams and columns of the walking beam furnace employs a double-layer structure of insulation and anti-slag adhesion layers with appropriate thicknesses, enhancing the overall integrity of the insulation lining and improving its comprehensive performance. However, this patent still cannot solve the problems of long construction cycles, large fluctuations in construction quality, and cracking and damage caused by the anchor + castable construction method.

[0005] The invention patent with publication number CN105444579A discloses a method for wrapping the water beam of a heating furnace. A fixing block is set on the outer surface of the water pipe at the bottom of the furnace. Precast blocks A and B are made of insulating material with a thermal conductivity of less than 1.0 W / m·K and are made into semi-cylindrical precast blocks. Precast blocks A and B are fitted together to form a cylinder and have grooves of the same size as the fixing block inside. Precast blocks A and B are installed on the outside of the water pipe at the bottom of the furnace and their internal grooves are tightly connected to the fixing block. Finally, the connection between precast blocks A and B and the connection between precast blocks A and B and the water pipe at the bottom of the furnace are sealed with high-temperature mortar. This patent uses metal fixing blocks welded onto water-cooled steel pipes to fix precast blocks A and B. Due to the large difference in thermal expansion coefficients between metal materials and insulation materials, cracks are easily generated at the corners of the joint due to stress concentration, leading to damage. In addition, insulation materials with a thermal conductivity of less than 1.0 W / m·K have a relatively high thermal conductivity and insufficient thermal insulation performance. Furthermore, the metal fixing blocks are larger in volume than conventional anchors, resulting in a more significant heat island effect and accelerating local heat transfer.

[0006] The utility model disclosed in CN216745396U is a novel walking beam column insulation component for a steel rolling heating furnace, comprising multiple insulation bodies, each insulation body having a tenon and mortise structure; adjacent insulation bodies are connected end to end by the tenon and mortise structure to form an annular insulation layer wrapped around the water beam column. The insulation component in this invention is assembled from an insulation body with a mortise and tenon structure. The mortise and tenon structure replaces the traditional clamping method, and the interlocking of the arc-shaped tenon and mortise improves installation convenience while strengthening the connection of the insulation body at high temperatures. To ensure the dimensional accuracy of the mortise and tenon structure, it is manufactured using laser cutting. Meanwhile, the insulation body uses a novel nanoporous aerogel insulation material, effectively improving the insulation performance of the component. However, novel nanoporous aerogel insulation materials often have drawbacks such as low strength and low operating temperature. The maximum operating temperature of SiO2 nanoporous aerogel insulation material is generally below 800℃, and its resistance to iron oxide scale and ferrous silicate corrosion, as well as its resistance to high-temperature flue gas erosion, is poor, making it difficult to meet the performance requirements for long-term use in steel rolling furnaces at temperatures of 900–1300℃.

[0007] Utility model patent CN216282703U discloses a heat-insulating and energy-saving structure for a heating furnace water beam. From the cold side to the hot side, the structure consists of a flexible nanoplate, a ceramic fiber blanket, and a castable refractory. The flexible nanoplate and ceramic fiber blanket are sewn together with stitching, and the castable refractory is fixed with Y-shaped anchors. Double-sided adhesive can be applied to the surface of the flexible nanoplate. This heat-insulating and energy-saving structure for a heating furnace water beam perfectly covers the water beam wall panel, ensuring service life and performance. It effectively solves the problem of temporary water repellency and can be temporarily adhered to the water beam wall panel, reducing construction difficulty. It also has an extremely low thermal conductivity, effectively reducing heat loss. However, this patent still cannot solve the problems of long construction cycles, large fluctuations in construction quality, and cracking and damage caused by the anchor + castable refractory construction method.

[0008] In summary, the existing traditional water-beam and column insulation structures, which employ a double-layer composite structure, suffer from problems such as long construction time, large fluctuations in construction quality, poor insulation performance, and short service life. Some invention patents have explored prefabricated insulation methods, but issues such as insufficient high-temperature performance or insulation performance still exist. Therefore, it is necessary to further research a rapidly constructable double-water-pipe column insulation structure for steel rolling heating furnaces. This structure should ensure high-temperature performance while achieving comprehensive goals such as improving column insulation performance, reducing furnace energy consumption, extending the service life of the column insulation lining, shortening construction time, and enhancing radiative heat transfer at the furnace bottom. Summary of the Invention

[0009] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a quick-construction double-water-pipe column thermal insulation structure for steel rolling heating furnaces and its preparation method. This structure can achieve comprehensive goals such as improving the overall thermal insulation performance of the column, reducing the energy consumption of the heating furnace, extending the service life of the column thermal insulation lining, shortening the construction time, and enhancing the radiative heat transfer at the furnace bottom.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A rapidly constructable double-water-pipe column insulation structure for a steel rolling heating furnace is disclosed. This structure forms the furnace column connecting the furnace bottom and the crossbeam insulation lining. The furnace column comprises two water-cooled steel pipes connected by flat steel. The outer surfaces of the double-water-cooled steel pipes are sequentially coated from the inside out with an aerogel insulation coating, a nanoporous insulation board layer, a refractory fiber blanket layer, a thermal expansion compensation layer, a lightweight high-strength mullite prefabricated component layer, and an infrared high-emissivity thermal barrier coating. The main chemical composition and mass percentage of the lightweight high-strength mullite prefabricated component layer are: Al₂O₃≥70%, SiO₂≤26%, Fe₂O₃<0.7%, K₂O+Na₂O<0.8%, with the remainder being unavoidable impurities. The main performance indicators of the lightweight high-strength mullite prefabricated component layer are: density 0.9-1.1 g / cm³. 3 Compressive strength ≥3MPa, thermal conductivity ≤0.45W / m·K (hot surface temperature 600℃), softening temperature T under 0.05MPa load. 0.5 ≥1470℃.

[0012] Preferably, the infrared high emissivity thermal barrier coating is formed by spraying a perovskite-type infrared high emissivity thermal barrier coating; the perovskite-type infrared high emissivity thermal barrier coating comprises the following components by mass percentage: 30-45% Ca / Cr ion-doped LaAlO3 perovskite radiative elements, 10-20% aluminum dihydrogen phosphate aqueous solution, 35-55% calcium hexaaluminate fine powder thermal insulation filler, and 0.5-1.5% polycarboxylic acid high-efficiency dispersant.

[0013] Preferably, the lightweight high-strength mullite prefabricated layer is formed by sequentially splicing and stacking a set of bottom elliptical ring prefabricated parts and multiple sets of upper elliptical ring prefabricated parts with mortise and tenon joints.

[0014] Preferably, the bottom elliptical ring prefabricated component is formed by mortise and tenon joints of two first prefabricated components and two second prefabricated components;

[0015] The first precast component is a semi-circular structure with a flat bottom that contacts the bottom of the heating furnace. A first arc-shaped tenon is provided in the middle of the top, and a first long strip tenon and a first long strip mortise are provided in the middle of both ends, respectively.

[0016] The second precast component has a flat side and a protrusion on the other side that matches the concave surface in the middle of the double water-cooled steel pipe. Its bottom is flat and contacts the bottom of the heating furnace. A first tenon is provided in the middle of the top, and a second long tenon and a second long mortise are provided in the middle of both ends, respectively.

[0017] The bottom elliptical ring prefabricated component is formed by sequentially mortising and tenoning together one of the first prefabricated components, one of the second prefabricated components, another of the first prefabricated components, and another of the second prefabricated components.

[0018] Preferably, the upper elliptical ring prefabricated component is formed by mortise and tenon joints of two third prefabricated components and two fourth prefabricated components;

[0019] The third prefabricated component is a semi-circular structure with an arc-shaped mortise at the middle of its bottom, a second arc-shaped tenon at the middle of its top, and a third elongated tenon and a third elongated mortise at the middle of its two ends, respectively.

[0020] The fourth prefabricated component has a flat side and a protruding side that matches the concave surface in the middle of the double water-cooled steel pipe. A first mortise is provided at the middle position of its bottom, a second tenon is provided at the middle position of its top, and a fourth elongated tenon and a fourth elongated mortise are provided at the middle positions of both ends, respectively.

[0021] The upper elliptical ring prefabricated component is formed by sequentially mortising and tenoning together one of the third prefabricated components, one of the fourth prefabricated components, another of the third prefabricated components, and another of the fourth prefabricated components.

[0022] Preferably, the bottom elliptical ring precast component is joined to the adjacent upper elliptical ring precast component by means of its first arc-shaped tenon and first tenon respectively fitting with the arc-shaped mortise and first mortise of the adjacent upper elliptical ring precast component; the upper elliptical ring precast component is joined to the adjacent upper elliptical ring precast component by means of its bottom arc-shaped mortise and first mortise respectively fitting with the second arc-shaped tenon and second tenon of the adjacent upper elliptical ring precast component.

[0023] Preferably, the thermal expansion fastening compensation layer is formed by the thermal expansion coating itself growing under heat expansion; the thermal expansion coating is applied to the inner side of the lightweight high-strength mullite preform layer, and comprises the following components by mass percentage: 25-40% self-crosslinking acrylic emulsion, 10-20% ammonium polyphosphate (degree of polymerization ≥1000), 2-5% dipentaerythritol, 5-10% melamine, 15-30% calcium hexaaluminate ultrafine powder (particle size ≤10μm), and 15-25% deionized water.

[0024] Preferably, the refractory fiber blanket layer is formed by splicing together a single layer of refractory fiber blanket, with Z-shaped right-angle steps at both ends of the splicing position; the nanoporous heat insulation board layer is formed by splicing together two continuous double semi-annular columnar nanoporous heat insulation boards, with Z-shaped right-angle steps at both ends of the splicing position; the aerogel heat insulation coating is formed by spraying aerogel heat insulation paint.

[0025] A method for preparing a rapidly constructible double-water-pipe column thermal insulation structure for a steel rolling heating furnace involves applying an aerogel thermal insulation coating, wrapping it with a nanoporous thermal insulation board layer and a refractory fiber blanket layer on the outside of the double water-cooled steel pipes, first compacting and fixing it using a thermal insulation layer compaction and fixing mold, and then constructing a lightweight high-strength mullite precast layer. After each lightweight high-strength mullite precast layer is constructed, the thermal insulation layer compaction and fixing mold is moved upwards. The thermal insulation layer compaction and fixing mold is composed of two symmetrical mold components hinged together, and its outer contour is consistent with the cross-sectional shape of the double water-cooled steel pipes. It can be opened from one side and locked with a button after closing.

[0026] Preferably, it includes the following steps:

[0027] 1) Apply a thermal expansion coating to the inside of all the first, second, third and fourth preforms. When heated during operation, it will form a thermal expansion and fastening compensation layer. After application, allow it to air dry at room temperature.

[0028] 2) Clean the surface of the double water-cooled steel pipes that serve as the foundation of the heating furnace column, and spray aerogel heat insulation coating on the surface to form an aerogel heat insulation coating.

[0029] 3) Wrap a nanoporous heat insulation board with Z-shaped right-angle steps at both ends around the aerogel heat insulation coating, and fix it with plastic film to form a nanoporous heat insulation board layer.

[0030] 4) Wrap a layer of refractory fiber blanket with Z-shaped right-angle steps at both ends around the nanoporous insulation board layer to form a refractory fiber blanket layer. Wrap and compact the refractory fiber blanket using an insulation layer compaction and fixing mold, and control the compression of the refractory fiber blanket to be 10-20%.

[0031] 5) Install two second prefabricated pieces with thermal expansion coating on the inner side into the recess between the double water-cooled steel pipes wrapped with aerogel insulation coating, nanoporous insulation board layer and refractory fiber blanket layer and place them at the bottom of the heating furnace. Then, mortise and tenon splice a first prefabricated piece with thermal expansion coating on the inner side from the left and right sides respectively to form a bottom elliptical ring prefabricated piece, which contacts the bottom of the heating furnace. Press the insulation layer to fix the mold upward and move it to the outer wall of the next section of refractory fiber blanket layer.

[0032] 6) Take two fourth precast pieces with thermal expansion coating on the inner side and place them in the recess between the double water-cooled steel pipes wrapped with aerogel insulation coating, nanoporous insulation board layer and refractory fiber blanket layer, and place them on the bottom elliptical ring precast piece. Then, mortise and tenon splice a third precast piece with thermal expansion coating on the inner side from the left and right sides respectively to form an upper elliptical ring precast piece. Then, mortise and tenon splice the upper and lower elliptical ring precast piece on the top of the bottom elliptical ring precast piece. Press the insulation layer to fix the mold upward and move it to the outer wall of the next section of refractory fiber blanket layer.

[0033] 7) Take two more fourth precast pieces with thermal expansion coating on the inner side and place them in the recess between the double water-cooled steel pipes wrapped with aerogel insulation coating, nanoporous insulation board layer and refractory fiber blanket layer, and place them on the previous upper elliptical ring precast piece. Then, mortise and tenon splice a third precast piece with thermal expansion coating on the inner side from the left and right sides respectively to form another upper elliptical ring precast piece. Then, mortise and tenon splice the upper and lower parts of the upper elliptical ring precast piece and install it on the top of the previous upper elliptical ring precast piece. Then, pull out the insulation layer compaction and fixing mold upward and move it to the outer wall of the next section of refractory fiber blanket layer.

[0034] 8) Repeat step 7) and continue to install the upper elliptical ring precast component. After setting a 3-5mm expansion joint at about half the height of the double water-cooled steel pipe, continue to repeat step 7) and build to the top of the double water-cooled steel pipe. Remove the insulation layer and compact the mold to complete the production of the heating furnace column.

[0035] 9) After curing for 12 hours, the construction of the crossbeam insulation lining connected to the top of the heating furnace column is completed according to the double insulation lining method of refractory fiber blanket + self-flowing castable. After demolding, an infrared high emissivity thermal barrier coating is sprayed on the surface of the lightweight high-strength mullite precast layer and the crossbeam insulation lining to finally form the overall water beam and column insulation structure of the heating furnace.

[0036] The contact surfaces of the mortise and tenon joints and the stacking are all bonded and sealed with high-temperature refractory mortar.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] This invention provides a rapidly constructable double-water-pipe column thermal insulation structure for steel rolling heating furnaces and its preparation method. Through optimized design of multi-layer thermal insulation materials based on different operating temperature ranges, the thermal insulation performance and high-temperature performance of the column are improved. By combining the mortise and tenon structure with the thermal expansion self-locking structure, anchors and metal fixing blocks are eliminated, thus eliminating problems such as material thermal expansion mismatch, stress concentration damage, and heat island effect. It has the advantages of short construction time, excellent thermal insulation performance, resistance to oxidation and iron scale corrosion, and improved furnace emissivity.

[0039] This invention significantly improves the thermal insulation performance of columns by selecting a lightweight, high-strength mullite precast layer for the hot-face working layer, which reduces the thermal conductivity from 0.9 to below 0.45 W / m·K (hot-face temperature 600℃) compared to conventional Al2O3-SiO2 self-flowing castable refractory used for water beams.

[0040] This invention replaces the existing method of casting and curing with castable refractory by using a combined design of mortise and tenon joints, refractory mortar bonding and sealing, and a self-locking structure of thermal expansion compensation layer for lightweight, high-strength mullite precast components. It eliminates the need for metal anchors and metal fixing blocks, solving problems such as material thermal expansion mismatch, stress concentration damage, and heat island effect. At the same time, it eliminates a series of construction processes such as casting, curing, and furnace drying, significantly shortening the fabrication and construction time of the heating furnace column insulation lining, reducing the number of days of furnace shutdown for maintenance, and improving production efficiency.

[0041] This invention improves the high-temperature performance of the column insulation lining in high-temperature flue gas environments by coating the outer side of the lightweight, high-strength mullite prefabricated layer with an infrared high-emissivity thermal barrier coating. This coating utilizes the high high-temperature infrared emissivity, low thermal conductivity, good high-temperature stability of the perovskite crystal phase, and difficulty in reacting with iron oxide scale at high temperatures. The high-temperature infrared emissivity (900-1300℃) of the working lining in the 1-2.5μm band is increased from 0.3 to over 0.9, thus overcoming the defects of lightweight, high-strength mullite materials such as low high-temperature infrared emissivity and poor resistance to iron oxide scale corrosion.

[0042] Based on the varying operating temperatures of different areas within the insulation layer, a multi-layer design incorporating refractory fiber blankets, nanoporous insulation boards, and aerogel insulation coatings is optimized to further enhance the insulation performance of the columns. The high-temperature resistance and low thermal conductivity of the refractory fiber blankets are fully utilized as a transitional insulation layer adjacent to the prefabricated working layer on the hot side. When the operating temperature drops below 500℃, the low thermal conductivity of the nanoporous insulation boards is leveraged to ensure they operate within their optimal performance temperature range, guaranteeing excellent insulation performance over long-term use and effectively preventing performance degradation. When the temperature in the area in contact with the water pipes drops below 300℃, the ultra-low thermal conductivity of the aerogel insulation coating and its ability to tightly bond and coat the outer wall of the water pipes ensure that the aerogel insulation coating operates within a suitable temperature range (below 350℃), maintaining the integrity of the nanoporous structure of the aerogel material, improving material lifespan, and preventing insulation performance degradation.

[0043] This invention utilizes a Z-shaped right-angle step design at the joint between the refractory fiber blanket and the nanoporous insulation board. This avoids the problem of increased overlap area size affecting the external circular dimension deviation of the column insulation layer caused by conventional overlapping construction, while simultaneously reducing the impact of splicing gaps. Furthermore, the use of a compaction mold for the insulation layer to fix and compact the refractory fiber blanket solves the problem of difficulty in compacting and fixing irregularly shaped areas with dual water pipes in the absence of anchors.

[0044] This invention utilizes a thermal expansion and fastening compensation layer design. It employs ultrafine calcium hexaaluminate powder as filler and a combination of ammonium polyphosphate, dipentaerythritol, and melamine as a foaming agent. By leveraging the volume expansion of the thermal expansion coating at elevated temperatures (≥300℃), a porous calcium hexaaluminate thermal expansion and fastening compensation layer is formed. This layer possesses a low thermal conductivity and can fill the gaps between the prefabricated hot-face components and the insulation layer, further compacting the refractory fiber blanket and improving the overall performance, insulation performance, and service life of the multi-layer insulation lining structure of the heating furnace column. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a quick-construction double-water-pipe column heat insulation structure for a steel rolling heating furnace, according to a specific embodiment of the present invention.

[0046] Figure 2 for Figure 1 A schematic diagram of the AA section of the bottom elliptical ring precast component.

[0047] Figure 3 for Figure 2 Schematic diagram of the CC section.

[0048] Figure 4 for Figure 1 Schematic diagram of the BB section of the upper and middle elliptical ring prefabricated component.

[0049] Figure 5 for Figure 4 Schematic diagram of the FF section.

[0050] Figure 6 for Figure 2 At point D and Figure 4 A magnified view of point G in the middle.

[0051] Figure 7 for Figure 2 Middle E and Figure 4 A magnified view of point H in the middle.

[0052] Figure 8 for Figure 2 A three-dimensional structural schematic diagram of the first prefabricated component.

[0053] Figure 9 , Figure 10 for Figure 2 A three-dimensional structural schematic diagram of the second prefabricated component.

[0054] Figure 11 for Figure 10 Top view of the second precast component.

[0055] Figure 12 for Figure 4 A three-dimensional structural schematic diagram of the third prefabricated component.

[0056] Figure 13 for Figure 12 The main view of the third prefabricated component.

[0057] Figure 14 for Figure 12 Top view of the third prefabricated component.

[0058] Figure 15 , Figure 16 for Figure 4 A three-dimensional structural schematic diagram of the fourth prefabricated component.

[0059] Figure 17 for Figure 16 Top view of the fourth precast component.

[0060] Figure 18 for Figure 16 Right view of the fourth precast component.

[0061] Figure 19 A schematic diagram showing the opening / closing state of the mold for compacting and fixing the insulation layer.

[0062] Figure reference numerals: 1. Infrared high emissivity thermal barrier coating, 2. Lightweight high-strength mullite prefabricated layer (including: bottom elliptical ring prefabricated part 2.1, upper elliptical ring prefabricated part 2.2), 3. Thermal expansion fastening compensation layer, 4. Refractory fiber blanket layer, 5. Nanoporous heat insulation board layer, 6. Aerogel heat insulation coating, 7. Double water-cooled steel pipe, 8. Furnace bottom of heating furnace, 9. Insulation layer compaction and fixing mold, 10. Heating furnace column, 11. Crossbeam heat insulation lining;

[0063] The bottom elliptical ring prefabricated component 2.1 includes a first prefabricated component 2.11 (of which, a first arc-shaped tenon 2.11a, a first elongated tenon 2.11b, and a first elongated mortise 2.11c) and a second prefabricated component 2.12 (a first tenon 2.12a, a second elongated mortise 2.12b, and a second elongated tenon 2.12c).

[0064] The upper elliptical ring prefabricated component 2.2 includes a third prefabricated component 2.21 (of which, the arc-shaped mortise 2.21a, the second arc-shaped tenon 2.21b, the third elongated tenon 2.21c, and the third elongated mortise 2.21d) and a fourth prefabricated component 2.22 (the first mortise 2.22a, the second tenon 2.22b, the fourth elongated mortise 2.22c, and the fourth elongated tenon 2.22d). Detailed Implementation

[0065] To better explain the present invention, the main contents of the present invention are further illustrated below with reference to specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0066] like Figure 1-18 As shown, this invention provides a rapidly constructable double-water-pipe column insulation structure for a steel rolling heating furnace. It forms a heating furnace column 10 connecting the furnace bottom 8 and the crossbeam insulation lining 11. The heating furnace column 10 includes double water-cooled steel pipes 7, each composed of two water-cooled steel pipes connected by flat steel. The outer sides of the double water-cooled steel pipes 7 are sequentially covered from the inside out with an aerogel insulation coating 6, a nanoporous insulation board layer 5, a refractory fiber blanket layer 4, a thermal expansion fastening compensation layer 3, a lightweight high-strength mullite prefabricated component layer 2, and an infrared high emissivity thermal barrier coating 1. The overall insulation structure does not use metal anchors or fixing blocks.

[0067] The high-emissivity infrared thermal barrier coating 1 is a perovskite-type high-emissivity infrared thermal barrier coating applied by spraying, with a thickness of 0.2-1 mm and an infrared emissivity ≥0.90 in the 1-2.5 μm band. The perovskite-type high-emissivity infrared thermal barrier coating comprises the following components by mass percentage: 30-45% Ca / Cr ion-doped LaAlO3 perovskite radiative elements (200 mesh), 10-20% aluminum dihydrogen phosphate aqueous solution (50% content), 35-55% calcium hexaaluminate fine powder thermal insulation filler (200 mesh), and 0.5-1.5% polycarboxylate-based high-efficiency dispersant.

[0068] The lightweight, high-strength mullite precast layer 2 is constructed by sequentially joining and stacking a set of bottom elliptical ring precast parts 2.1 and multiple sets of upper elliptical ring precast parts 2.2 using mortise and tenon joints. The bottom elliptical ring precast parts 2.1 and the upper elliptical ring precast parts 2.2 are both 60-300mm high and 50-80mm thick.

[0069] The bottom elliptical ring precast component 2.1 is assembled from two first precast components 2.11 and two second precast components 2.12 using mortise and tenon joints. The first precast component 2.11 has a semi-circular structure with a flat bottom that contacts the furnace bottom 8. A first arc-shaped tenon 2.11a is provided at the middle of the top, and a first elongated tenon 2.11b and a first elongated mortise 2.11c are provided at the middle of both ends, respectively. The second precast component 2.12 has a flat side on one side and a protrusion on the other side that matches the concave surface in the middle of the double water-cooled steel pipe 7. Its bottom is flat and contacts the furnace bottom 8. A first tenon 2.12a is provided at the middle of the top, and a second elongated tenon 2.12c and a second elongated mortise 2.12b are provided at the middle of both ends, respectively.

[0070] The bottom elliptical ring precast component 2.1 is formed by mortise and tenon jointing one first precast component 2.11, one second precast component 2.12, another first precast component 2.11, and another second precast component 2.12 in sequence.

[0071] The upper elliptical ring prefabricated component 2.2 is assembled from two third prefabricated components 2.21 and two fourth prefabricated components 2.22 using mortise and tenon joints. The third prefabricated component 2.21 has a semi-circular structure with an arc-shaped mortise 2.21a at the center of its bottom, a second arc-shaped tenon 2.21b at the center of its top, and a third elongated tenon 2.21c and a third elongated mortise 2.21d at the center of both ends. The fourth prefabricated component 2.22 has a flat side on one side and a protrusion on the other side that matches the concave surface in the middle of the double water-cooled steel pipe 7. It has a first mortise 2.22a at the center of its bottom, a second tenon 2.22b at the center of its top, and a fourth elongated tenon 2.22d and a fourth elongated mortise 2.22c at the center of both ends, respectively.

[0072] The upper elliptical ring precast component 2.2 is formed by mortise and tenon joints of one third precast component 2.21, one fourth precast component 2.22, another third precast component 2.21, and another fourth precast component 2.22.

[0073] The bottom elliptical ring prefabricated component 2.1 is joined to the adjacent upper elliptical ring prefabricated component 2.2 by its first arc-shaped tenon 2.11a and first tenon 2.12a, respectively, with the arc-shaped mortise 2.21a and first mortise 2.22a. The upper elliptical ring prefabricated component 2.2 is joined to the adjacent upper elliptical ring prefabricated component 2.2 by its bottom arc-shaped mortise 2.21a and first mortise 2.22a, respectively, with the second arc-shaped tenon 2.21b and second tenon 2.22b.

[0074] The cross-sections of all the tenons and mortises mentioned above are semi-circular, and the diameter of the semi-circular cross-section of the tenon is 2-5mm smaller than the diameter of the semi-circular cross-section of the mortis it is joined with.

[0075] All contact surfaces of the mortise and tenon joints and stacking are bonded and sealed with high-temperature refractory mortar; the high-temperature refractory mortar is an air-hardening refractory mortar with a maximum service temperature (under oxidizing atmosphere) ≥1500℃; the high-temperature refractory mortar is TJM air-hardening refractory mortar produced by Morgan Thermal Ceramics Co., Ltd.

[0076] The main chemical composition of the lightweight, high-strength mullite precast layer 2 is: Al2O3 ≥ 70%, SiO2 ≤ 26%, Fe2O3 < 0.7%, K2O + Na2O < 0.8%, with the balance being unavoidable impurities; performance indicators: density 0.9-1.1 g / cm³. 3 Compressive strength ≥3MPa, thermal conductivity ≤0.45W / m·K (hot surface temperature 600℃), softening temperature T under 0.05MPa load. 0.5 ≥1470℃.

[0077] The thermal expansion fastening compensation layer 3 has a thickness of 3-5 mm and is formed by the thermal expansion coating itself growing under thermal expansion at temperatures exceeding 300℃. The thermal expansion coating is applied to the inner side of the lightweight, high-strength mullite preform layer 2, with a thickness of 0.2-1 mm. Its components and mass percentage content are as follows: self-crosslinking acrylic emulsion 25-40%, ammonium polyphosphate (degree of polymerization ≥1000) 10-20%, dipentaerythritol 2-5%, melamine 5-10%, calcium hexaaluminate ultrafine powder (particle size ≤10μm) 15-30%, and deionized water 15-25%.

[0078] The refractory fiber blanket layer 4 is 20-35mm thick and is composed of single-layer refractory fiber blankets wrapped and spliced ​​together. Z-shaped right-angle steps are set at both ends of the splice to reduce the impact of the splice gaps. The material performance indicators of the refractory fiber blanket are as follows: density 160kg / m³. 3 The operating temperature is ≥1100℃, the slag ball content is ≤10%, and the thermal conductivity is ≤0.18W / m·K (hot surface temperature 800℃). The refractory fiber blanket is one of the following: high-alumina aluminosilicate refractory fiber blanket, zirconium-containing aluminosilicate refractory fiber blanket, or alkaline earth metal refractory fiber blanket.

[0079] The nanoporous insulation layer 5 is 5-10mm thick and is composed of two continuous, double-semi-annular columnar nanoporous insulation panels spliced ​​together. Z-shaped right-angle steps are set at both ends of the splice to reduce the impact of the joint gap. The material performance indicators of the nanoporous insulation panel are as follows: density ≤0.45g / cm³. 3 Thermal conductivity ≤0.05W / m·K (hot surface temperature 800℃), room temperature compressive strength ≥0.4MPa, shrinkage rate ≤0.4% (1000℃×24h).

[0080] The aerogel thermal insulation coating 6 has a thickness of 0.5-1mm and is formed by spraying aerogel thermal insulation paint. The performance indicators of the aerogel thermal insulation paint are as follows: density ≤0.045g / cm³. 3 Operating temperature ≥300℃, thermal conductivity ≤0.055W / m·K.

[0081] The aerogel insulation coating 6, the nanoporous insulation board layer 5, and the fire-resistant fiber blanket layer 4 form the insulation layer outside the double water-cooled steel pipe 7.

[0082] The above-mentioned method for preparing the rapidly constructible double-water-pipe column insulation structure for steel rolling heating furnaces includes the following steps: Double water-cooled steel pipes 7, covered with an insulation layer (aerogel insulation coating 6 + nanoporous insulation board layer 5 + refractory fiber blanket layer 4), are compacted and fixed using an insulation layer compaction and fixing mold 9. Then, lightweight high-strength mullite precast component layer 2 is constructed. After each lightweight high-strength mullite precast component layer 2 is completed, the insulation layer compaction and fixing mold 9 is moved upwards. The insulation layer compaction and fixing mold 9 is composed of two symmetrical mold components hinged together, such as... Figure 19 As shown, its outer contour is consistent with the cross-sectional shape of the double water-cooled steel pipe 7; the insulation layer compaction and fixing mold 9 is made of PVC material with a thickness of 1-2mm, which can be opened from one side and locked by a button after closing.

[0083] The above preparation method specifically includes the following steps:

[0084] 1) Apply a thermal expansion coating to the inner side of all lightweight high-strength mullite first preform 2.11, second preform 2.12, third preform 2.21 and fourth preform 2.22. When heated during operation, it will form a thermal expansion and fastening compensation layer 3. After coating, air dry at room temperature for ≥12 hours.

[0085] 2) Use a steel brush to clean the dust and rust from the surface of the double water pipe steel pipe 7, which serves as the foundation of the heating furnace column 10, and spray aerogel heat insulation coating on the surface to form an aerogel heat insulation coating 6. After ≥12 hours, proceed to the next step.

[0086] 3) Wrap a nanoporous heat insulation board with Z-shaped right-angle steps at both ends around the aerogel heat insulation coating 6, and wrap and fix it with plastic film to form nanoporous heat insulation board layer 5.

[0087] 4) Wrap a layer of refractory fiber blanket with Z-shaped right-angle steps at both ends around the nanoporous insulation board layer 5 to form refractory fiber blanket layer 4. Open the insulation layer compaction and fixing mold 9 to wrap and compact the refractory fiber blanket layer 4, and lock it with a button to control the compression of the refractory fiber blanket to 10-20%.

[0088] 5) Apply high-temperature refractory mortar to the bottom, top, and both ends of the two first precast pieces 2.11 with thermal expansion coating on their inner sides and the two second precast pieces 2.12 with thermal expansion coating on their inner sides. First, install the two second precast pieces 2.12 in the recessed part in the middle of the double water-cooled steel pipe 7 wrapped with insulation layer and place them at the bottom 8 of the heating furnace. Then, mortise and tenon join one of the first precast pieces 2.11 from the left and right sides respectively. The second long strip tenon 2 of one of the second precast pieces 2.12. 12c and the second elongated tenon 2.12b are respectively joined with the first elongated tenon 2.11c of one first precast part 2.11 and the first elongated tenon 2.11b of another first precast part 2.11, forming a bottom elliptical ring precast part 2.1 with the two first precast parts 2.11 and the two second precast parts 2.12, which contacts the furnace bottom 8 of the heating furnace. The insulation layer is compacted and fixed by high-temperature refractory mortar, and the mold 9 is pulled upward and moved to the outer wall of the next section of the insulation layer.

[0089] 6) Apply high-temperature refractory mortar to the top and both ends of the two third precast pieces 2.21 (with inner sides coated with thermal expansion coating) and the two fourth precast pieces 2.22 (with inner sides coated with thermal expansion coating). First, place the two fourth precast pieces 2.22 in the recessed area between the double water-cooled steel pipes 7 (which are wrapped with insulation layer) and place them on the bottom elliptical ring precast piece 2.1. Then, mortise and tenon join one third precast piece 2.21 from the left and right sides respectively. Among them, the fourth elongated tenon 2.22d and the fourth elongated mortise 2.22 of one fourth precast piece 2.22 are... c is respectively joined with the third long strip mortise 2.21d of one third precast part 2.21 and the third long strip tenon 2.21c of another third precast part 2.21, and the two third precast parts 2.21 and the two fourth precast parts 2.22 are combined to form an upper elliptical ring precast part 2.2, and the upper and lower elliptical ring precast part 2.2 is installed on the top of the bottom elliptical ring precast part 2.1 with mortise and tenon joints. The insulation layer is compacted and sealed by high temperature refractory mortar, and the mold 9 is pulled upward and moved to the outer wall of the next section of insulation layer.

[0090] 7) Continue applying high-temperature refractory mortar to the tops and ends of the two third precast pieces 2.21 (with inner sides coated with thermal expansion coating) and the two fourth precast pieces 2.22 (with inner sides coated with thermal expansion coating). First, place the two fourth precast pieces 2.22 in the recessed area between the double water-cooled steel pipes 7 (which are wrapped with insulation layers) and place them on the upper elliptical ring precast piece 2.2. Then, mortise and tenon join a third precast piece 2.21 from the left and right sides respectively. Among them, the fourth elongated tenon 2.22d and the fourth elongated mortise 2.22 of one fourth precast piece 2.22... c is respectively joined with the third elongated groove 2.21d of one third prefabricated part 2.21 and the third elongated tenon 2.21c of another third prefabricated part 2.21, and the two third prefabricated parts 2.21 and the two fourth prefabricated parts 2.22 are combined to form another upper elliptical ring prefabricated part 2.2, and the upper and lower elliptical ring prefabricated part 2.2 is installed on the top of the previous upper elliptical ring prefabricated part 2.2 by mortise and tenon splicing. The insulation layer is compacted and sealed by high temperature refractory mortar, and the mold 9 is pulled upward and moved to the outer wall of the next section of insulation layer;

[0091] 8) Repeat step 7) and continue to install the upper elliptical ring precast component 2.2. After building to about half the height of the double water-cooled steel pipe 7, use ceramic fiber paper to set a 3-5mm expansion joint and continue to repeat step 7) until the top of the double water-cooled steel pipe 7 is built. Remove the insulation layer and compact the mold 9 to complete the production of the heating furnace column 10.

[0092] 9) After curing for 12 hours, the construction of the crossbeam insulation lining 11 connected to the top of the heating furnace column 10 is completed according to the conventional method of making double insulation lining of refractory fiber blanket + self-flowing castable for water beams of heating furnace. After demolding, infrared high emissivity thermal barrier coating 1 is sprayed on the surface of lightweight high-strength mullite precast layer 2 and crossbeam insulation lining 11, and finally the construction of the overall water beam and column insulation lining of heating furnace is completed.

[0093] The following are several quick-installation double-water-pipe column insulation structures for steel rolling heating furnaces, with slight differences in size and materials:

[0094] Example 1

[0095] The specific parameters of the dimensions and materials of each component in this embodiment are as follows:

[0096] The outer diameter of each water-cooled steel pipe that makes up the double water-cooled steel pipe 7 is 140mm and the height is 1800mm.

[0097] The bottom elliptical ring precast component 2.1 and the upper elliptical ring precast component 2.2, which make up the lightweight and high-strength mullite precast component layer 2, are both 76 mm high and 60 mm thick. The semicircular diameters of the cross-sections of each tenon and mortise are 17 mm and 20 mm, respectively.

[0098] The infrared high emissivity thermal barrier coating 1 is a perovskite-type infrared high emissivity thermal barrier coating applied by spraying, with a thickness of 0.2 mm and an infrared emissivity of 0.90 in the 1-2.5 μm band. The main components of the perovskite-type infrared high emissivity thermal barrier coating are as follows by mass percentage: Ca / Cr ion-doped LaAlO3 perovskite radiative elements (200 mesh) 30%, aluminum dihydrogen phosphate aqueous solution (content 50%) 20%, thermal insulation filler calcium hexaaluminate fine powder (200 mesh) 49.5%, and polycarboxylic acid high-efficiency dispersant 0.5%.

[0099] The main chemical composition and mass percentage of the lightweight, high-strength mullite precast layer 2 are as follows: Al₂O₃ 70.2%, SiO₂ 24.1%, Fe₂O₃ 0.53%, K₂O + Na₂O 0.65%, with the balance being unavoidable impurities; performance index: density 0.95 g / cm³. 3 It has a compressive strength of 3.2 MPa, a thermal conductivity of 0.44 W / m·K (hot surface temperature 600℃), and a softening temperature T under a 0.05 MPa load. 0.5 It is 1470℃.

[0100] The high-temperature refractory mortar is TJM air-hardening refractory mortar produced by Morgan Thermal Ceramics Co., Ltd., with a maximum service temperature (under oxidizing atmosphere) ≥1500℃.

[0101] The thickness of the thermal expansion fastening compensation layer 3 is 3 mm. The thickness of the thermal expansion coating is 0.5 mm, and its components and mass percentage content are as follows: 30% self-crosslinking acrylic emulsion, 15% ammonium polyphosphate (degree of polymerization ≥1000), 4% dipentaerythritol, 6% melamine, 30% calcium hexaaluminate ultrafine powder (particle size ≤10μm), and 15% deionized water.

[0102] The refractory fiber blanket layer 4 is 20mm thick, composed of 25mm thick refractory fiber blankets wrapped, compacted, and spliced ​​together. The refractory fiber blankets are made of alkaline earth metal refractory fiber blankets—Super Cotton Prime blankets—produced by Morgan Thermo-Ceramics Co., Ltd., with a density of 160kg / m³. 3 It has an operating temperature of 1150℃, a slag ball content of ≤5%, and a thermal conductivity of 0.18W / m·K (hot surface temperature 800℃). It has the advantages of low thermal conductivity, environmental friendliness, and non-carcinogenicity.

[0103] The thickness of the nanoporous insulation layer 5 is 5mm. The nanoporous insulation board uses WDS microporous insulation board manufactured by Morgan Thermo-Ceramics Co., Ltd., with a density of 0.36g / cm³. 3 Thermal conductivity 0.044 W / m·K (hot surface temperature 800℃), room temperature compressive strength 0.5 MPa, shrinkage rate 0.3% (1000℃×24h).

[0104] The aerogel thermal insulation coating 6 has a thickness of 0.5 mm and a density of 0.043 g / cm³. 3Operating temperature: 320℃, thermal conductivity: 0.052W / m·K.

[0105] When preparing the lightweight, high-strength mullite precast layer 2, the height of the expansion joint is set to 3mm.

[0106] The thickness of the insulation layer compaction and fixing mold 9 is 1mm.

[0107] Example 2

[0108] The specific parameters of the dimensions and materials of each component in this embodiment are as follows:

[0109] The outer diameter of each water-cooled steel pipe that makes up the double water-cooled steel pipe 7 is 194mm and the height is 2000mm.

[0110] The bottom elliptical ring precast component 2.1 and the upper elliptical ring precast component 2.2, which make up the lightweight and high-strength mullite precast component layer 2, are both 150 mm high and 70 mm thick. The semicircular diameters of the cross-sections of each tenon and mortise are 17 mm and 20 mm, respectively.

[0111] The infrared high emissivity thermal barrier coating 1 is a perovskite-type infrared high emissivity thermal barrier coating applied by spraying, with a thickness of 0.5 mm and an infrared emissivity of 0.91 in the 1-2.5 μm band. The main components of the perovskite-type infrared high emissivity thermal barrier coating are as follows by mass percentage: Ca / Cr ion-doped LaAlO3 perovskite radiation element (200 mesh) 35%, aluminum dihydrogen phosphate aqueous solution (content 50%) 20%, thermal insulation filler calcium hexaaluminate fine powder (200 mesh) 44%, and polycarboxylic acid high-efficiency dispersant 1%.

[0112] The main chemical composition and mass percentage of the lightweight, high-strength mullite precast layer 2 are as follows: Al₂O₃ 75.1%, SiO₂ 22.1%, Fe₂O₃ 0.49%, K₂O + Na₂O 0.42%, with the balance being unavoidable impurities; Main performance indicator: density 1.05 g / cm³. 3 It has a compressive strength of 3.1 MPa, a thermal conductivity of 0.45 W / m·K (hot surface temperature 600℃), and a softening temperature T under a 0.05 MPa load. 0.5 It is 1470℃.

[0113] The high-temperature refractory mortar is TJM air-hardening refractory mortar produced by Morgan Thermal Ceramics Co., Ltd., with a maximum service temperature (under oxidizing atmosphere) ≥1500℃.

[0114] The thermal expansion fastening compensation layer 3 is 4 mm thick and is formed by the self-expansion growth of a thermal expansion coating applied to the inner side of the lightweight high-strength mullite preform layer 2 at temperatures exceeding 300°C. The thermal expansion coating is 0.6 mm thick and its components and mass percentage content are as follows: 40% self-crosslinking acrylic emulsion, 10% ammonium polyphosphate (degree of polymerization ≥1000), 2% dipentaerythritol, 5% melamine, 25% calcium hexaaluminate ultrafine powder (particle size ≤10μm), and 18% deionized water.

[0115] The refractory fiber blanket layer 4 is 35mm thick, composed of 40mm thick refractory fiber blankets wrapped, compacted, and spliced ​​together. A single-layer Z-shaped right-angle step is installed at both ends of the splice to reduce the impact of the splice gaps. The refractory fiber blanket is a high-alumina aluminosilicate fiber blanket with a density of 160kg / m³. 3 Operating temperature 1200℃, slag ball content ≤10%, thermal conductivity 0.16W / m·K (hot surface temperature 800℃).

[0116] The 8mm thick nanoporous insulation layer 5 is composed of two semi-annular columnar nanoporous insulation panels joined together. Z-shaped right-angle steps are incorporated at both ends of the joint to minimize the impact of seams. The nanoporous insulation panels are WDS microporous insulation panels manufactured by Morgan Thermo-Ceramics Co., Ltd., with a density of 0.36 g / cm³. 3 Thermal conductivity 0.044 W / m·K (hot surface temperature 800℃), room temperature compressive strength 0.5 MPa, shrinkage rate 0.3% (1000℃×24h).

[0117] The aerogel thermal insulation coating 6 has a thickness of 0.8 mm and a density of 0.043 g / cm³. 3 Operating temperature: 320℃, thermal conductivity: 0.052W / m·K.

[0118] When preparing the lightweight, high-strength mullite precast layer 2, the height of the expansion joint is set to 4mm.

[0119] The thickness of the insulation layer compaction and fixing mold 9 is 1.5mm.

[0120] Example 3

[0121] The specific parameters of the dimensions and materials of each component in this embodiment are as follows:

[0122] The outer diameter of each water-cooled steel pipe that makes up the double water-cooled steel pipe 7 is 194mm and the height is 2150mm.

[0123] The bottom elliptical ring precast component 2.1 and the upper elliptical ring precast component 2.2, which make up the lightweight and high-strength mullite precast component layer 2, are both 300mm high and 80mm thick; the semicircular diameters of the cross sections of each tenon and mortise are 20mm and 25mm, respectively.

[0124] The infrared high emissivity thermal barrier coating 1 is a perovskite-type infrared high emissivity thermal barrier coating applied by spraying, with a thickness of 1 mm and an infrared emissivity of 0.93 in the 1-2.5 μm band. The main components of the perovskite-type infrared high emissivity thermal barrier coating are as follows by mass percentage: Ca / Cr ion-doped LaAlO3 perovskite radiative elements (200 mesh) 45%, aluminum dihydrogen phosphate aqueous solution (content 50%) 15%, thermal insulation filler calcium hexaaluminate fine powder (200 mesh) 38.5%, and polycarboxylic acid high-efficiency dispersant 1.5%.

[0125] The main chemical composition and mass percentage of the lightweight, high-strength mullite precast layer 2 are as follows: Al₂O₃ 78.3%, SiO₂ 19.2%, Fe₂O₃ 0.51%, K₂O + Na₂O 0.55%, with the balance being unavoidable impurities; performance index: density 0.98 g / cm³. 3 Withstanding pressure of 3.5 MPa, thermal conductivity of 0.35 W / m·K (hot surface temperature 600℃), softening temperature T under 0.05 MPa load. 0.5 The temperature is 1500℃.

[0126] The high-temperature refractory mortar is TJM air-hardening refractory mortar produced by Morgan Thermal Ceramics Co., Ltd., with a maximum service temperature (under oxidizing atmosphere) ≥1500℃.

[0127] The thickness of the thermal expansion fastening compensation layer 3 is 5 mm. The thickness of the thermal expansion coating is 0.8 mm, and its components and mass percentage content are as follows: 25% self-crosslinking acrylic emulsion, 20% ammonium polyphosphate (degree of polymerization ≥1000), 5% dipentaerythritol, 10% melamine, 15% calcium hexaaluminate ultrafine powder (particle size ≤10μm), and 25% deionized water.

[0128] The refractory fiber blanket layer 4 is 30mm thick, composed of 35mm thick refractory fiber blankets wrapped, compacted, and spliced ​​together. The refractory fiber blanket is a zirconium-aluminosilicate fiber blanket with a density of 160kg / m³. 3 Operating temperature 1350℃, slag ball content ≤10%, thermal conductivity 0.16W / m·K (hot surface temperature 800℃).

[0129] The thickness of layer 5 of the nanoporous insulation board is 10mm. The nanoporous insulation board uses a new type of high-strength nanoporous insulation board produced by Zhengzhou Jingwei Composite Materials Co., Ltd., with a density of 0.45g / cm³. 3 Thermal conductivity 0.042 W / m·K (hot surface temperature 800℃), room temperature compressive strength 1.3 MPa, shrinkage rate 0.4% (1000℃×24h).

[0130] The aerogel thermal insulation coating 6 has a thickness of 0.5 mm and a density of 0.040 g / cm³. 3 Operating temperature: 320℃, thermal conductivity: 0.048W / m·K.

[0131] When preparing the lightweight, high-strength mullite precast layer 2, the height of the expansion joint is set to 5mm.

[0132] The thickness of the insulation layer compaction and fixing mold 9 is 2mm.

[0133] All other unspecified parts belong to the prior art.

Claims

1. A rapidly constructable double-water-pipe column insulation structure for a steel rolling heating furnace, comprising a heating furnace column (10) connecting the furnace bottom (8) and the crossbeam insulation lining (11), the heating furnace column (10) including double water-cooled steel pipes (7), the double water-cooled steel pipes (7) being composed of two water-cooled steel pipes connected by flat steel, characterized in that: The double water-cooled steel pipe (7) is covered from the inside out with an aerogel thermal insulation coating (6), a nanoporous thermal insulation board layer (5), a refractory fiber blanket layer (4), a thermal expansion fastening compensation layer (3), a lightweight high-strength mullite prefabricated layer (2), and an infrared high emissivity thermal barrier coating (1). The main chemical composition and mass percentage of the lightweight high-strength mullite prefabricated layer (2) are: Al2O3≥70%, SiO2≤26%, Fe2O3<0.7%, K2O+Na2O<0.8%, with the remainder being unavoidable impurities. The main performance indicators of the lightweight high-strength mullite prefabricated layer (2) are: density 0.9-1.1 g / cm³. 3 Compressive strength ≥3MPa, thermal conductivity ≤0.45W / m•K, softening temperature T under 0.05MPa load. 0.5 ≥1470℃, of which the hot surface temperature during the thermal conductivity test is 600℃.

2. The rapidly constructable double-water-pipe column thermal insulation structure for steel rolling heating furnaces according to claim 1, characterized in that: The infrared high emissivity thermal barrier coating (1) is formed by spraying a perovskite-type infrared high emissivity thermal barrier coating; the perovskite-type infrared high emissivity thermal barrier coating includes the following components by mass percentage: 30-45% Ca / Cr ion-doped LaAlO3 perovskite radiation elements, 10-20% aluminum dihydrogen phosphate aqueous solution, 35-55% calcium hexaaluminate fine powder thermal insulation filler, and 0.5-1.5% polycarboxylic acid high-efficiency dispersant.

3. The rapidly constructable double-water-pipe column thermal insulation structure for steel rolling heating furnaces according to claim 1, characterized in that: The lightweight high-strength mullite precast layer (2) is formed by a set of bottom elliptical ring precast parts (2.1) and multiple sets of upper elliptical ring precast parts (2.2) being spliced ​​and stacked in sequence with mortise and tenon joints.

4. The rapidly constructable double-water-pipe column thermal insulation structure for steel rolling heating furnaces according to claim 3, characterized in that: The bottom elliptical ring prefabricated component (2.1) is formed by mortise and tenon joints of two first prefabricated components (2.11) and two second prefabricated components (2.12); The first precast component (2.11) is a semi-circular structure with a flat bottom that is in contact with the furnace bottom (8) of the heating furnace. A first arc-shaped tenon (2.11a) is provided at the middle position of the top, and a first long strip tenon (2.11b) and a first long strip mortise (2.11c) are provided at the middle positions of both ends, respectively. The second precast component (2.12) has a flat side and a protrusion on the other side that matches the concave surface in the middle of the double water-cooled steel pipe (7). Its bottom is flat and contacts the furnace bottom (8) of the heating furnace. A first tenon (2.12a) is provided in the middle of the top, and a second long strip tenon (2.12c) and a second long strip mortise (2.12b) are provided in the middle of both ends respectively. The bottom elliptical ring precast component (2.1) is formed by mortise and tenon jointing one of the first precast components (2.11), one of the second precast components (2.12), another of the first precast components (2.11), and another of the second precast components (2.12).

5. The rapidly constructable double-water-pipe column thermal insulation structure for steel rolling heating furnaces according to claim 3 or 4, characterized in that: The upper elliptical ring prefabricated component (2.2) is formed by mortise and tenon joints of two third prefabricated components (2.21) and two fourth prefabricated components (2.22); The third prefabricated component (2.21) is a semi-circular structure. An arc-shaped mortise (2.21a) is provided at the middle position of its bottom, a second arc-shaped tenon (2.21b) is provided at the middle position of its top, and a third elongated tenon (2.21c) and a third elongated mortise (2.21d) are provided at the middle positions of its two ends, respectively. The fourth precast component (2.22) has a flat side and a protrusion on the other side that matches the concave surface in the middle of the double water-cooled steel pipe (7). A first mortise (2.22a) is provided at the middle position of its bottom, a second tenon (2.22b) is provided at the middle position of its top, and a fourth elongated tenon (2.22d) and a fourth elongated mortise (2.22c) are provided at the middle positions of both ends, respectively. The upper elliptical ring prefabricated component (2.2) is formed by mortise and tenon joints of one of the third prefabricated components (2.21), one of the fourth prefabricated components (2.22), another of the third prefabricated components (2.21), and another of the fourth prefabricated components (2.22).

6. The rapidly constructable double-water-pipe column thermal insulation structure for a steel rolling heating furnace according to claim 5, characterized in that: The bottom elliptical ring precast component (2.1) is joined with the adjacent upper elliptical ring precast component (2.2) by its first arc tenon (2.11a) and first tenon (2.12a) respectively to the arc tenon (2.21a) and first tenon (2.22a) of its first arc tenon (2.11a) and first tenon (2.12a). The upper elliptical ring precast component (2.2) is joined with the adjacent upper elliptical ring precast component (2.2) by its second arc tenon (2.21b) and second tenon (2.22b) of its second arc tenon (2.21a) and first tenon (2.22a) of its first arc tenon (2.21a) and first tenon (2.22a).

7. The rapidly constructable double-water-pipe column thermal insulation structure for a steel rolling heating furnace according to claim 1, characterized in that: The thermal expansion fastening compensation layer (3) is formed by the thermal expansion coating itself expanding under heat; the thermal expansion coating is applied to the inner side of the lightweight high-strength mullite preform layer (2), and includes the following components by mass percentage: 25-40% self-crosslinking acrylic emulsion, 10-20% ammonium polyphosphate with a degree of polymerization ≥1000, 2-5% dipentaerythritol, 5-10% melamine, 15-30% calcium hexaaluminate ultrafine powder with a particle size ≤10μm, and 15-25% deionized water.

8. The rapidly constructable double-water-pipe column thermal insulation structure for a steel rolling heating furnace according to claim 1, characterized in that: The refractory fiber blanket layer (4) is made of a single layer of refractory fiber blanket wrapped and spliced ​​together, with Z-shaped right-angle steps set at both ends of the splicing position; the nanoporous heat insulation board layer (5) is made of two continuous double semi-annular columnar nanoporous heat insulation boards spliced ​​together, with Z-shaped right-angle steps set at both ends of the splicing position; the aerogel heat insulation coating (6) is made of aerogel heat insulation coating sprayed.

9. A method for preparing a rapidly constructable double-water-pipe column thermal insulation structure for a steel rolling heating furnace as described in claim 6, characterized in that: After applying an aerogel insulation coating (6), wrapping a nanoporous insulation board layer (5) and a refractory fiber blanket layer (4) on the outside of the double water-cooled steel pipe (7), the insulation layer is first compacted and fixed by the insulation layer compaction and fixing mold (9) before the construction of the lightweight high-strength mullite precast layer (2). After the construction of each lightweight high-strength mullite precast layer (2) is completed, the insulation layer compaction and fixing mold (9) is moved upward. The insulation layer compaction and fixing mold (9) is composed of two symmetrical mold parts hinged together. Its outer contour is consistent with the cross-sectional shape of the double water-cooled steel pipe (7). It can be opened from one side and locked by a button after closing.

10. The method for preparing the rapidly constructable double-water-pipe column thermal insulation structure for a steel rolling heating furnace according to claim 9, characterized in that: Includes the following steps: 1) Apply a thermal expansion coating to the inside of all the first preforms (2.11), the second preforms (2.12), the third preforms (2.21) and the fourth preforms (2.22). When heated during operation, the coating will form a thermal expansion and fastening compensation layer (3). After coating, air dry at room temperature. 2) Clean the surface of the double water-cooled steel pipe (7) that serves as the foundation of the heating furnace column (10), and spray aerogel heat insulation coating on the surface to form an aerogel heat insulation coating (6). 3) Wrap a nanoporous heat insulation board with Z-shaped right-angle steps at both ends on the outside of the aerogel heat insulation coating (6), and wrap and fix it with plastic film to form a nanoporous heat insulation board layer (5). 4) Wrap a layer of refractory fiber blanket with Z-shaped right-angle steps at both ends around the nanoporous insulation board layer (5) to form a refractory fiber blanket layer (4), and use the insulation layer compaction and fixing mold (9) to wrap and compact it, controlling the compression of the refractory fiber blanket to be 10-20%; 5) Install two second prefabricated pieces (2.12) with thermal expansion coating on the inner side in the recess of the double water-cooled steel pipe (7) which is wrapped with aerogel insulation coating (6), nanoporous insulation board layer (5) and refractory fiber blanket layer (4) and place it at the bottom of the heating furnace (8). Then, mortise and tenon splice a first prefabricated piece (2.11) with thermal expansion coating on the inner side from the left and right sides respectively to form a bottom elliptical ring prefabricated piece (2.1), which contacts the bottom of the heating furnace (8). Pull out the insulation layer compaction and fixing mold (9) upward and move it to the outer wall of the next section of refractory fiber blanket layer (4). 6) Take two pieces of the fourth preform (2.22) with the inner side coated with thermal expansion coating and place them in the recess of the double water-cooled steel pipe (7) which is wrapped with aerogel insulation coating (6), nano-microporous insulation board layer (5) and refractory fiber blanket layer (4) and place them on the bottom elliptical ring preform (2.1). Then, mortise and tenon splice a piece of the third preform (2.21) with the inner side coated with thermal expansion coating from the left and right sides respectively to form an upper elliptical ring preform (2.2). Then, mortise and tenon splice the upper and lower elliptical ring preform (2.2) on the bottom elliptical ring preform (2.1). Pull out the insulation layer compaction and fixing mold (9) upward and move it to the outer wall of the next section of refractory fiber blanket layer (4). 7) Take two more fourth precast pieces (2.22) with thermal expansion coating on the inner side and place them in the recess of the double water-cooled steel pipe (7) wrapped with aerogel insulation coating (6), nanoporous insulation board layer (5) and refractory fiber blanket layer (4) and place them on the previous upper elliptical ring precast piece (2.2). Splice a third precast piece (2.21) with thermal expansion coating on the inner side from the left and right sides respectively to form another upper elliptical ring precast piece (2.2). Then, install the upper elliptical ring precast piece (2.2) with the upper and lower mortise and tenon joints on the top of the previous upper elliptical ring precast piece (2.2). Pull out the insulation layer compaction and fixing mold (9) upward and move it to the outer wall of the next section of refractory fiber blanket layer (4). 8) Repeat step 7) and continue to install the upper elliptical ring precast component (2.2). After setting a 3-5mm expansion joint at about half the height of the double water-cooled steel pipe (7), continue to repeat step 7) and build to the top of the double water-cooled steel pipe (7). Remove the insulation layer and compact the mold (9) to complete the production of the heating furnace column (10). 9) After curing for 12 hours, the construction of the crossbeam insulation lining (11) connected to the top of the heating furnace column (10) was completed according to the double insulation lining method of refractory fiber blanket + self-flowing castable. After demolding, infrared high emissivity thermal barrier coating (1) was sprayed on the surface of the lightweight high-strength mullite precast layer (2) and the crossbeam insulation lining (11) to finally form the overall water beam and column insulation structure of the heating furnace. The contact surfaces of the mortise and tenon joints and the stacking are all bonded and sealed with high-temperature refractory mortar.

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