Anti-erosion and anti-thermal shock lining structure of hazardous waste rotary kiln and its construction method

Abstract

The application discloses a hazardous waste rotary kiln refractory material anti-erosion and anti-thermal shock lining structure and a building method, and belongs to the technical field of rotary kilns.The hazardous waste rotary kiln refractory material anti-erosion and anti-thermal shock lining structure comprises an outer shell body, a buffer interlayer, an inner shell mechanism and a high-temperature calcination section lining, the inner side of the outer shell body is attached with the buffer interlayer, and the inner side of the buffer interlayer is attached with the inner shell mechanism.The double-layer shell body cooperates with an X-shaped buffer interlayer, and is matched with an inner shell staggered groove structure, so that heat conduction and thermal expansion and cold contraction stress release can be effectively blocked, and gradient heat insulation can be realized by relying on a multilayer composite heat preservation structure;the lining is fixed firmly by relying on Y-shaped anchoring nails;different refractory materials are selected and matched according to the working conditions of the kiln body to form the inner linings of different sections;chromium corundum composite bricks are used to engage staggered joints to build a high-temperature section to prevent loosening and seepage, and a high-temperature and salt-erosion-resistant protective coating is additionally used for protection, so that the anti-erosion and anti-thermal shock abilities of the lining are greatly improved, and the overall service life is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of rotary kiln technology, specifically relating to the erosion-resistant and thermal shock-resistant lining structure and construction method of refractory materials for hazardous waste rotary kilns. Background Technology

[0002] Rotary kilns for hazardous waste are core high-temperature incineration equipment in the field of harmless disposal of industrial hazardous waste. They mainly rely on the continuous rotation of the kiln body in conjunction with the high-temperature environment inside to complete the pyrolysis, incineration and solidification of various solid and semi-solid hazardous wastes. The equipment is in a complex working environment of high-temperature radiation, material erosion, flue gas corrosion and frequent temperature changes for a long time. The performance of the lining inside the kiln body directly determines the operational stability and actual service life of the entire equipment, and is also a key structure to ensure the safe and efficient operation of hazardous waste disposal.

[0003] Currently, most conventional hazardous waste rotary kilns on the market have refractory lining structures inside. These are mostly formed by integral casting of a single material refractory castable or by laying ordinary standard refractory bricks. The lining layer is fixed to the inner wall of the kiln by anchoring structures alone. The overall structure is simply designed with layers, without differentiated material selection and structural optimization based on the different working conditions of different areas along the axial direction of the rotary kiln. There is also no buffer and heat insulation adaptation structure between the inner and outer shells. The lining layer only provides basic high-temperature protection. For example, a hazardous waste incineration rotary kiln disclosed in Chinese patent CN107883383B has improved the wear of the support and drive devices under the rotary kiln body. The rotary kiln body is not easy to slide down along the material movement direction. At the same time, it avoids black smoke and backfire at the kiln head, realizes continuous and stable operation of the incineration system, and ensures the safety and reliability of the incineration system.

[0004] While the lining structure of the aforementioned rotary kiln can meet the basic requirements for high temperature resistance and internal protection in hazardous waste incineration operations, it still has the following drawbacks:

[0005] 1. Without an independent inner shell and supporting buffer and heat insulation structure, the outer shell of the kiln directly bears the high temperature heat radiation, resulting in serious heat loss. The thermal expansion and contraction deformation of the cylinder caused by heating cannot be effectively buffered and released, which easily leads to problems such as cylinder deformation, stress concentration and damage. At the same time, the deformation of the shell can directly pull and squeeze the inner lining, causing the lining to crack and fall off.

[0006] 2. The refractory materials were not selected and constructed according to the different working conditions of the kiln body axis. The refractory materials in each area are highly general and weakly targeted. The erosion resistance at the feeding end is insufficient, the thermal shock resistance at the discharge end is poor, the brick masonry structure in the high-temperature section is simple, and long-term hot and cold cycles can easily lead to loosening and misalignment. The brick joints are easily penetrated by flue gas and ash.

[0007] 3. The lining has weak overall resistance to salt corrosion and corrosion, and there is no dedicated protective structure to block the molten salt and acid and alkali corrosive flue gas generated during incineration. The inner lining matrix is ​​easily corroded and pulverized, the lining wears out quickly, the equipment requires frequent maintenance and repair, and the overall service life is short. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an anti-erosion and thermal shock lining structure and construction method for refractory materials in hazardous waste rotary kilns.

[0009] The technical solution adopted to solve the above technical problems is:

[0010] Firstly, a technical solution is provided: an erosion-resistant and thermal shock-resistant lining structure for a rotary kiln refractory material, comprising an outer shell body, a buffer interlayer, an inner shell mechanism, and a high-temperature calcination section lining. The inner side of the outer shell body is fitted with a buffer interlayer, and the inner shell mechanism is fitted with an inner shell mechanism. The inner shell mechanism includes an inner shell body, and multiple Y-shaped anchoring nails are welded to the inner side of the inner shell body. An outer strip groove is opened on the outer side of the inner shell body, and an inner strip groove is opened on the inner side of the inner shell body.

[0011] The inner shell mechanism is built with an elastic buffer leveling layer, and the inner side of the elastic buffer leveling layer is built with a composite heat insulation layer. The inner side of the composite heat insulation layer is divided into a feeding flushing section, a high-temperature main calcination section, an intermediate transition section and a discharge thermal shock section according to the axial working conditions of the kiln body.

[0012] The feeding flushing section is lined with a feeding flushing section lining, the high-temperature main calcination section is lined with a high-temperature calcination section lining, the high-temperature calcination section lining is constructed of multiple chromium corundum composite bricks, one side of each chromium corundum composite brick is integrally formed with a protruding side inlay, the other side is integrally formed with a recessed side inlay, one end of each chromium corundum composite brick is integrally formed with a protruding end face inlay, the other end is integrally formed with a recessed end face inlay, the intermediate transition section is lined with an intermediate transition section lining, and the discharge thermal shock section is lined with a discharge thermal shock section lining.

[0013] Furthermore, the outer shell body is made of carbon structural steel plate, the inner shell body is made of heat-resistant stainless steel plate, the outer and inner sides of the buffer interlayer are welded and fixed to the outer shell body and the inner shell body respectively, the buffer interlayer is made of heat-resistant austenitic stainless steel, and the cross-section of the buffer interlayer is in the form of multiple circumferentially arranged X-shapes. The buffer interlayer is used to reduce the heat transfer between the inner shell body and the outer shell body, and to provide space for the inner shell body to expand and contract with heat.

[0014] Through the above technical solution, the outer shell body made of carbon structural steel plate has the advantages of high structural strength and low cost, and can stably bear the overall equipment load. The inner shell body made of heat-resistant stainless steel can resist the high temperature radiation and corrosive flue gas erosion in the kiln. The X-shaped circumferentially arranged buffer interlayer between the two not only relies on its own bending structure to lengthen the heat conduction path and form a sealed air cavity to greatly reduce the heat conduction from the inner shell body to the outer shell body, reducing the overall temperature rise of the outer shell, but also uses the elastic deformation margin of the X-shape itself to effectively adapt to the thermal expansion and contraction deformation generated by the inner shell body during operation, release the compressive stress generated between the shells, and avoid problems such as welding cracks and structural deformation caused by thermal expansion difference between the inner and outer shells, effectively improving the operational stability and service life of the entire rotary kiln lining outer shell combination structure.

[0015] Furthermore, both the outer and inner strip grooves are axially slotted, and the outer and inner strip grooves are circumferentially staggered to release the stress caused by thermal expansion and contraction, providing expansion margin for the inner shell body.

[0016] Through the above technical solution, the axially set outer strip groove can form a fitting and positioning structure with the buffer interlayer, limiting the circumferential displacement of the buffer interlayer. The inner strip groove can form an interlocking connection with the inner buffer insulation layer, improving the firmness of the inner lining. The two types of grooves are arranged circumferentially to avoid structural weak areas in the same radial position of the inner shell body. At the same time, the reserved gaps in the grooves effectively conduct internal stress generated by thermal expansion and contraction, leaving sufficient deformation space for the inner shell body, preventing the inner shell body from twisting and deforming due to thermal compression, and further ensuring the overall structural regularity and long-term stability of the inner shell mechanism.

[0017] Furthermore, the elastic buffer leveling layer is composed of high-temperature plastic refractory mortar and elastic refractory fiber felt. The elastic buffer leveling layer is set close to the inner wall of the inner shell body to offset the thermal expansion and contraction deformation of the kiln body, level the installation base surface, and block the transmission of hard stress between layers.

[0018] Through the above technical solution, the elastic buffer leveling layer is closely attached to the inner wall of the inner shell body. It can not only rely on its own composite material characteristics to smooth the base surface of the inner shell body, providing a regular installation foundation for the subsequent laying and construction of the composite heat insulation layer, but also flexibly adapt to the deformation and displacement during the operation of the kiln body, effectively offsetting the thermal expansion and contraction deformation generated by the inner shell structure, blocking the hard stress transmission between the inner shell body and the composite heat insulation layer, avoiding stress concentration that causes the heat insulation layer to crack and fall off. At the same time, it can also fill the gaps in the inner strip groove, enhance the tightness of the interlayer bonding, and comprehensively improve the buffer adaptability and structural integrity of the lining structure.

[0019] Furthermore, the composite thermal insulation layer is formed by composite casting of thermal insulation castable SD-1.0 and outer thermal insulation and wear-resistant castable SD-NC03. The discharge end is thickened and a multi-layer thermal insulation structure is set. The thermal insulation layer is firmly fixed by Y-shaped anchor nails, and has both low thermal conductivity insulation and flue gas blocking performance.

[0020] Through the above technical solution, the composite thermal insulation layer adopts a double-layer composite casting structure of SD-1.0 and SD-NC03, which can fully combine the performance advantages of the two castables. The SD-1.0 substrate has an extremely low thermal conductivity, which can effectively block the outward transfer of high-temperature heat, while the SD-NC03 surface layer has excellent corrosion resistance, wear resistance and impermeability, which can prevent corrosive flue gas and trace amounts of molten slag from penetrating into the interior of the thermal insulation layer. By setting up a thickened multi-layer thermal insulation structure at the discharge end, the shortcomings of the discharge end, which is characterized by severe temperature fluctuations and large heat loss, are specifically compensated for, thereby improving the thermal insulation effect at the discharge end. At the same time, the entire composite thermal insulation layer is fixed by Y-shaped anchor nails, which effectively avoids the problems of hollowing, falling off and slipping of the thermal insulation layer under high-temperature conditions, greatly improving the overall structural stability, thermal insulation performance and resistance to flue gas erosion of the lining layer, and reducing the overall heat loss of the kiln.

[0021] Furthermore, both the inner lining of the feed flushing section and the inner lining of the intermediate transition section are cast from chromium corundum castable SD-19B, with no gaps in the overall construction, which can resist the high-speed flushing of materials and the slight corrosion of flue gas with high strength.

[0022] Through the above technical solution, the lining of the feeding and flushing section and the lining of the intermediate transition section are integrally cast using SD-19B chromium corundum castable. The one-piece molding structure eliminates the gaps between bricks, which can effectively prevent dust and corrosive flue gas from seeping and flowing through the gaps. Relying on the high strength, wear resistance and corrosion resistance of this material, it can withstand the high-speed impact and flushing of materials at the feeding end and the erosion of flue gas in the transition section for a long time. It is not easy for surface peeling, wear and damage to occur. It can effectively adapt to the different working conditions of the two sections, extend the service life of the lining, and ensure the stability of the internal working conditions of the kiln.

[0023] Furthermore, the chromium corundum composite bricks are laid in a ring along the inner wall of the composite thermal insulation layer. Two circumferentially adjacent chromium corundum composite bricks interlock with each other through the side protruding inlay and the side recessed inlay. The axially adjacent chromium corundum composite bricks interlock with each other through the end face protruding inlay and the end face recessed inlay. The axially adjacent chromium corundum composite bricks adopt a staggered arrangement structure.

[0024] Through the above technical solutions, chromium corundum composite bricks achieve a tight interlocking connection in both the circumferential and axial directions using a concave-convex inlay structure. This significantly improves the bonding and firmness between bricks, effectively preventing loosening, displacement, and detachment of bricks during rotary kiln rotation. Combined with the axial staggered joint arrangement, it can completely block straight through gaps, reducing the infiltration of high-temperature flue gas and molten slag. At the same time, it can evenly distribute the thermal stress and mechanical load generated in the high-temperature calcination section. When the lining of the high-temperature calcination section undergoes repeated thermal expansion and contraction deformation, the interlocking structure can continuously play a limiting and locking role, offsetting the displacement deviation caused by deformation. This prevents the gap between bricks from widening and the connection from loosening under long-term hot and cold cycles, effectively preventing brick loosening and misalignment from a structural perspective. This further enhances the overall structural strength, integrity, and long-term operational stability of the lining of the high-temperature calcination section, significantly improving its comprehensive performance in terms of thermal shock resistance, deformation resistance, and resistance to media erosion.

[0025] Furthermore, the lining of the discharge thermal shock section is cast from corundum mullite castable SD-180 to adapt to the harsh working conditions of frequent hot and cold alternation at the discharge end.

[0026] Through the above technical solution, the lining of the discharge thermal shock section is integrally cast using SD-180 corundum mullite castable. This material has excellent thermal shock resistance and temperature and alternating load resistance, which can perfectly adapt to the harsh operating conditions of frequent hot and cold alternation and large temperature fluctuations at the discharge end of the rotary kiln. It can effectively resist structural cracking and surface peeling caused by frequent sudden temperature changes. At the same time, it also has good medium-temperature corrosion resistance, which can resist the erosion of flue gas and residual heat dust at the discharge end, firmly protect the kiln body discharge end lining structure, effectively extend the service life of the discharge end lining, and ensure the continuous and stable operation of the equipment.

[0027] Furthermore, the inner surfaces of the feed flushing section lining, the high-temperature calcination section lining, the intermediate transition section lining, and the discharge thermal shock section lining are uniformly sprayed with a high-temperature resistant and salt-corrosion resistant protective coating. The protective coating completely covers the exposed surfaces of the brick and the castable, and is used to isolate the molten salt and acid-alkali corrosive flue gas generated by hazardous waste incineration, thereby slowing down the lining corrosion rate.

[0028] Through the above technical solution, a high-temperature resistant and salt-corrosion-resistant protective coating is sprayed onto the inner walls of the linings in the feeding flushing section, high-temperature calcination section, intermediate transition section, and discharge thermal shock section. This coating can completely cover all castable surfaces, exposed surfaces of chromium corundum composite bricks, and splicing gaps, forming a dense protective barrier on the innermost side of the lining. This effectively prevents molten salts, acidic and alkaline corrosive flue gases generated during hazardous waste incineration from directly eroding the lining matrix, avoiding the penetration of corrosive media into the material and causing pulverization, loosening, and peeling. This comprehensively reduces the rate of corrosion damage to the linings in each section, simultaneously improving the overall corrosion resistance and durability of the lining structure, and significantly extending the overall service life of the entire lining structure.

[0029] Secondly, based on the first aspect above, a method for constructing an anti-erosion and thermal shock lining structure for refractory materials in hazardous waste rotary kilns is also provided, including the following specific steps:

[0030] Step 1: Remove rust and oil stains from the inner working surface of the outer shell body and grind it to ensure that the welding base surface is flat and clean; fully weld the outer side of the heat-resistant austenitic stainless steel buffer interlayer with X-shaped cross section and circumferential arrangement to the corresponding position of the inner side of the outer shell body, ensuring that each X-shaped structure is evenly arranged and without deformation, and leaving room for thermal expansion deformation; then weld the outer side of the inner shell body to the inner side of the buffer interlayer to complete the overall assembly of the inner and outer shells;

[0031] Step 2: Open an outer strip groove on the outer side of the inner shell body and an inner strip groove on the inner side in the axial direction to ensure that the two types of grooves are staggered in the circumferential direction; weld and fix multiple Y-shaped anchors evenly on the inner side of the inner shell body.

[0032] Step 3: First, lay a composite elastic buffer leveling layer on the inner wall of the inner shell body, and form a mechanical fit with the inner strip groove to flatten the lining base surface and offset the deformation stress of the shell; after the leveling layer has cured, pour SD-1.0 heat insulation castable and SD-NC03 heat insulation and wear-resistant castable in layers to form an integral composite heat insulation layer. Thicken the discharge end position and pour a multi-layer heat insulation structure. The entire process is supported and shaped by Y-type anchor nails and cured until the strength meets the standard.

[0033] Step 4: Construct the kiln in sections according to its axial working conditions. The feeding flushing section and the intermediate transition section are integrally cast using SD-19B chromium corundum castable to form the inner lining of the feeding flushing section and the intermediate transition section, respectively. The discharge thermal shock section is cast using SD-180 corundum mullite castable to form the inner lining of the discharge thermal shock section. The inner linings of the feeding flushing section, the intermediate transition section, and the discharge thermal shock section are also fixed by Y-shaped anchor nails. The high-temperature main calcination section is constructed using chromium corundum composite bricks in a ring. The circumferential bricks are joined by the protruding inlay on the side and the recessed inlay on the side. The axial bricks are fitted by the protruding inlay on the end face and the recessed inlay on the end face. The whole structure adopts a staggered arrangement to ensure that the masonry is tight and there are no straight gaps.

[0034] Step 5: After the inner lining structure of each section has been completely cured and dried, a high-temperature resistant and salt-corrosion resistant protective coating is evenly sprayed on all exposed surfaces of the inner layers of the inner lining of the feeding flushing section, the high-temperature calcination section, the intermediate transition section, and the discharge thermal shock section, completely covering the brick body, the surface of the castable, and the gaps between the bricks; after the spraying is completed, room temperature curing and low-temperature kiln drying gradient treatment are carried out to eliminate the moisture inside the lining, and finally the construction of the overall lining structure is completed.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. This invention uses a double-layer shell with an X-shaped buffer interlayer to effectively block heat conduction and adaptively release thermal expansion and contraction stress. Combined with the staggered groove structure of the inner shell body, it ensures the stability of the shell structure. At the same time, it relies on a multi-layer composite insulation structure to achieve gradient heat insulation. The lining is firmly fixed by Y-shaped anchors, resulting in excellent overall heat insulation and shock absorption effects.

[0037] 2. This invention selects different refractory materials to form the inner lining of each section according to the working conditions of the kiln. In the high-temperature section, chrome corundum composite bricks are interlocked and staggered to form anti-loosening and anti-seepage material, and then a high-temperature resistant and salt-corrosion resistant protective coating is applied. It can be accurately adapted to complex working conditions such as scouring, high temperature, thermal shock and strong corrosion, which greatly improves the lining's damage resistance and extends the overall service life. Attached Figure Description

[0038] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0039] Figure 2 This is a three-dimensional sectional view of the present invention;

[0040] Figure 3 This is a schematic diagram of the buffer sandwich structure of the present invention;

[0041] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0042] Figure 5 This is a schematic diagram of the inner shell mechanism of the present invention;

[0043] Figure 6 yes Figure 5 Enlarged view at point B in the middle;

[0044] Figure 7 This is a partial three-dimensional cross-sectional view of the composite heat insulation layer, the feed flushing section lining, the high-temperature calcination section lining, and the intermediate transition section lining of the present invention.

[0045] Figure 8 This is a schematic diagram of the high-temperature calcination section lining construction of the present invention;

[0046] Figure 9 This is a schematic diagram of the chromium corundum composite brick structure of the present invention;

[0047] Figure 10 This is a schematic diagram of the assembly of the chromium corundum composite brick of the present invention.

[0048] Reference numerals: 1. Outer shell body; 2. Buffer interlayer; 3. Inner shell mechanism; 301. Inner shell body; 302. Y-shaped anchor; 303. Outer strip groove; 304. Inner strip groove; 4. Elastic buffer leveling layer; 5. Composite heat insulation layer; 6. Inner lining of the feeding flushing section; 7. Inner lining of the high-temperature calcination section; 701. Chromium corundum composite brick; 702. Side protruding inlay part; 703. Side recessed inlay part; 704. End face protruding inlay part; 705. End face recessed inlay part; 8. Inner lining of the intermediate transition section; 9. Inner lining of the discharge thermal shock section. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0050] like Figures 1-10As shown, the refractory material anti-erosion and thermal shock lining structure of the hazardous waste rotary kiln includes an outer shell body 1, a buffer interlayer 2, an inner shell mechanism 3, and a high-temperature calcination section lining 7. The buffer interlayer 2 is fitted to the inner side of the outer shell body 1, and the inner shell mechanism 3 is fitted to the inner side of the buffer interlayer 2. The inner shell mechanism 3 includes an inner shell body 301, with multiple Y-shaped anchor bolts 302 welded to the inner side of the inner shell body 301. An outer strip groove 303 is formed on the outer side of the inner shell body 301, and an inner strip groove 304 is formed on the inner side of the inner shell body 301. The outer shell body 1 is made of carbon structural steel plate, and the inner shell body 301 is made of heat-resistant stainless steel plate. The outer side of the buffer interlayer 2 and... The inner sides are welded and fixed to the outer shell body 1 and the inner shell body 301 respectively. The buffer interlayer 2 is made of heat-resistant austenitic stainless steel, and the cross-section of the buffer interlayer 2 is arranged in multiple circumferential X-shapes. The buffer interlayer 2 is used to reduce the heat transfer between the inner shell body 301 and the outer shell body 1, and to provide space for thermal expansion and contraction of the inner shell body 301. The outer strip groove 303 and the inner strip groove 304 are both axially slotted, and the outer strip groove 303 and the inner strip groove 304 are circumferentially staggered to release the stress of thermal expansion and contraction and provide expansion margin for the inner shell body 301. The outer shell body 1, made of carbon structural steel plate, has high structural strength and low cost. The advantages of this design include its ability to stably withstand the overall equipment load. The heat-resistant stainless steel inner shell 301 can resist high-temperature radiation and corrosive flue gas erosion inside the kiln. The X-shaped circumferentially arranged buffer interlayer 2 between the two not only extends the heat conduction path by its own bending structure and forms a sealed air cavity to significantly reduce heat conduction from the inner shell 301 to the outer shell 1, reducing the overall temperature rise of the outer shell, but also effectively adapts to the thermal expansion and contraction deformation of the inner shell 301 during operation by utilizing the elastic deformation margin of the X-shape itself. This releases the compressive stress generated between the shells and avoids problems such as welding cracks and structural deformation caused by the thermal expansion difference between the inner and outer shells, effectively improving the overall quality of the rotary kiln lining. The operational stability and service life of the side shell assembly structure are ensured by the axially arranged outer strip groove 303, which can form a fitting and positioning structure with the buffer interlayer 2, limiting the circumferential displacement of the buffer interlayer 2. The inner strip groove 304 can form an interlocking connection with the inner buffer insulation layer, improving the firmness of the inner lining. The two types of grooves are arranged circumferentially to avoid structural weak areas in the same radial position of the inner shell body 301. At the same time, the reserved gaps in the grooves effectively dissipate the internal stress generated by thermal expansion and contraction, providing sufficient deformation space for the inner shell body 301 and preventing the inner shell body 301 from twisting and deforming due to thermal compression. This further ensures the overall structural regularity and long-term stability of the inner shell mechanism 3.

[0051] like Figure 1 and Figure 2As shown, an elastic buffer leveling layer 4 is built on the inner side of the inner shell structure 3. The elastic buffer leveling layer 4 is composed of high-temperature plastic refractory mortar and elastic refractory fiber felt. The elastic buffer leveling layer 4 is set tightly against the inner wall of the inner shell body 301 to offset the thermal expansion and contraction deformation of the kiln body, level the installation base surface, and block the transmission of hard stress between layers. The elastic buffer leveling layer 4 is laid tightly against the inner wall of the inner shell body 301. It can not only rely on its own composite material properties to level the base surface of the inner wall of the inner shell body 301, providing a regular installation foundation for the subsequent laying and construction of the composite heat insulation layer 5, but also flexibly adapt to the operation of the kiln body. The deformation and displacement during the process effectively offset the thermal expansion and contraction deformation generated by the inner shell mechanism 3, block the hard stress transmission between the inner shell body 301 and the composite heat insulation layer 5, and avoid stress concentration causing the heat insulation layer to crack and fall off. At the same time, it can also fill the gap of the inner strip groove 304, enhance the tightness of the interlayer bonding, and comprehensively improve the buffer adaptability and structural integrity of the lining structure. The inner side of the elastic buffer leveling layer 4 is built with the composite heat insulation layer 5. The inner side of the composite heat insulation layer 5 is divided into the feeding flushing section, the high-temperature main calcination section, the intermediate transition section and the discharge thermal shock section according to the axial working conditions of the kiln body. The composite thermal insulation layer 5 is formed by composite casting of thermal insulation castable SD-1.0 and outer thermal insulation and wear-resistant castable SD-NC03. The outlet end is thickened with a multi-layer thermal insulation structure. The entire thermal insulation layer is firmly fixed by Y-shaped anchors 302, possessing both low thermal conductivity insulation and flue gas barrier properties. The composite thermal insulation layer 5 adopts a double-layer composite casting structure of SD-1.0 and SD-NC03, which can fully combine the performance advantages of the two castables. The SD-1.0 base material has an extremely low thermal conductivity, which can effectively block the outward transfer of high-temperature heat. SD-NC03... The surface layer possesses excellent corrosion resistance, wear resistance, and impermeability, preventing corrosive fumes and trace amounts of molten slag from penetrating the insulation layer. By thickening the multi-layer insulation structure at the discharge end, it specifically compensates for the shortcomings of the discharge end's intense temperature fluctuations and large heat loss, improving the insulation effect at the discharge end. At the same time, relying on Y-type anchor nails 302 to hang and lock the overall composite insulation layer 5, it effectively avoids problems such as hollowing, falling off, and slippage of the insulation layer under high-temperature conditions, significantly improving the overall structural stability, insulation performance, and resistance to fumes, and reducing the overall heat loss of the kiln.

[0052] like Figure 2 and Figure 7As shown, the feeding flushing section is lined with a feeding flushing section lining 6, and the intermediate transition section is lined with an intermediate transition section lining 8. Both the feeding flushing section lining 6 and the intermediate transition section lining 8 are cast from SD-19B chromium corundum castable, forming a seamless structure that can withstand high-speed material scouring and mild flue gas corrosion. The integral casting of the feeding flushing section lining 6 and the intermediate transition section lining 8 with SD-19B chromium corundum castable eliminates brick splicing gaps, effectively preventing dust and corrosive flue gas from seeping through the gaps. Relying on the high strength, wear resistance, and corrosion resistance of this material, it can withstand the high-speed impact and scouring of materials at the feeding end and the erosion of flue gas in the transition section for a long time, and is not prone to surface peeling, wear, or damage. It effectively adapts to the different operating conditions of the two sections, extends the service life of the lining, and ensures the stability of the internal operating conditions of the kiln.

[0053] like Figures 7-10 As shown, the high-temperature main calcination section is constructed with a high-temperature calcination section lining 7, which is composed of multiple chromium corundum composite bricks 701. One side of each chromium corundum composite brick 701 has an integrally formed protruding side inlay 702, and the other side has an integrally formed concave side inlay 703. One end of each chromium corundum composite brick 701 has an integrally formed end-face protruding inlay 704, and the other end has an integrally formed end-face concave inlay 705. The chromium corundum composite bricks 701 are laid in a ring along the inner wall of the composite thermal insulation layer 5. Two circumferentially adjacent chromium corundum composite bricks 701 interlock with each other through the protruding side inlay 702 and the concave side inlay 703. Axially adjacent chromium corundum composite bricks 701 interlock with each other through the concave side inlay 703 and the protruding end-face inlay 704. Furthermore, the axially adjacent chromium corundum composite bricks 701 are arranged in a staggered pattern. Brick 701 utilizes a concave-convex interlocking structure to achieve a tight interlocking connection in both the circumferential and axial directions. This significantly improves the bonding and firmness between bricks, effectively preventing loosening, displacement, and detachment of bricks during rotary kiln rotation. Combined with the axial staggered joint arrangement, it can completely block straight through gaps, reducing the infiltration of high-temperature flue gas and molten ash. At the same time, it can evenly distribute the thermal stress and mechanical load generated in the high-temperature calcination section. When the lining 7 in the high-temperature calcination section undergoes repeated thermal expansion and contraction deformation, the interlocking structure can continuously play a limiting and locking role, offsetting the displacement deviation caused by deformation. This prevents the gaps between bricks from widening and the connection from loosening under long-term hot and cold cycles, effectively preventing brick loosening and misalignment from a structural perspective. This further enhances the overall structural strength, integrity, and long-term operational stability of the lining 7 in the high-temperature calcination section, significantly improving its comprehensive performance in terms of thermal shock resistance, deformation resistance, and resistance to media erosion.

[0054] like Figure 2 and Figure 7As shown, the discharge thermal shock section is lining 9, which is cast from corundum mullite castable SD-180. This lining is designed to withstand the harsh conditions of frequent temperature fluctuations at the discharge end. The discharge thermal shock section lining 9 is integrally cast using SD-180 corundum mullite castable, a material with excellent thermal shock resistance and resistance to alternating temperature loads. It perfectly adapts to the harsh operating conditions of frequent temperature fluctuations and large temperature ranges at the rotary kiln discharge end, effectively resisting structural cracking and surface peeling caused by frequent temperature changes. It also possesses good medium-temperature corrosion resistance, resisting erosion from flue gas and residual heat dust at the discharge end, firmly protecting the kiln body's discharge end lining structure, effectively extending the service life of the discharge end lining, and ensuring continuous and stable equipment operation. The inner linings of the feed flushing section lining 6, the high-temperature calcination section lining 7, the intermediate transition section lining 8, and the discharge thermal shock section lining 9 are also included. A high-temperature resistant and salt-corrosion-resistant protective coating is uniformly sprayed onto the surface of the layer. The protective coating completely covers the exposed surfaces of the brick and castable, and is used to isolate the molten salt and acid- and alkali-corrosive flue gas generated by hazardous waste incineration, thus slowing down the lining corrosion rate. The high-temperature resistant and salt-corrosion-resistant protective coating is sprayed on the inner walls of the inner walls of the feeding flushing section lining 6, the high-temperature calcination section lining 7, the intermediate transition section lining 8, and the discharge thermal shock section lining 9. It can completely cover all the castable molding surfaces and the exposed surfaces and splicing gaps of the chrome corundum composite brick 701, and can form a dense protective barrier on the innermost side of the lining. It can effectively prevent the molten salt substances, acid and alkali corrosive flue gas generated during hazardous waste incineration from directly eroding the inner lining matrix, and prevent the corrosive media from penetrating into the material and causing powdering, loosening and peeling. It reduces the speed of corrosion damage to the inner lining of each section in all aspects, and at the same time improves the corrosion resistance and durability of the overall lining structure, and significantly extends the overall service life of the entire lining structure.

[0055] The construction method for the erosion-resistant and thermal shock-resistant lining structure of the refractory material for hazardous waste rotary kilns includes the following specific steps:

[0056] Step 1: Remove rust and oil stains from the inner working surface of the outer shell body 1 and grind it to ensure that the welding base surface is flat and clean; fully weld the outer side of the heat-resistant austenitic stainless steel buffer interlayer 2 with X-shaped cross section and circumferential arrangement to the corresponding position of the inner side of the outer shell body 1, ensuring that each X-shaped structure is evenly arranged and without deformation, and leaving room for thermal expansion deformation; then weld the outer side of the inner shell body 301 to the inner side of the buffer interlayer 2 to complete the overall assembly of the inner and outer shells;

[0057] Step 2: A lateral strip groove 303 is axially opened on the outer side of the inner shell body 301, and an inner strip groove 304 is axially opened on the inner side, ensuring that the two types of grooves are staggered in the circumferential direction; multiple Y-shaped anchor nails 302 are uniformly welded and fixed on the inner side of the inner shell body 301.

[0058] Step 3: First, lay a composite elastic buffer leveling layer 4 on the inner wall of the inner shell body 301, and form a mechanical fit with the inner strip groove 304 to flatten the lining base surface and offset the deformation stress of the shell; after the leveling layer has cured, pour SD-1.0 heat insulation castable and SD-NC03 heat insulation and wear-resistant castable in layers to form an integral composite heat insulation layer 5. Thicken the discharge end position and pour a multi-layer heat insulation structure. The entire process is supported and shaped by Y-type anchor nails 302 and cured until the strength meets the standard.

[0059] Step 4: Construct the kiln in sections according to the axial working conditions. The feeding flushing section and the intermediate transition section are integrally cast using SD-19B chromium corundum castable to form the inner lining 6 of the feeding flushing section and the inner lining 8 of the intermediate transition section, respectively. The discharge thermal shock section is cast using SD-180 corundum mullite castable to form the inner lining 9 of the discharge thermal shock section. The inner lining 6 of the feeding flushing section, the inner lining 8 of the intermediate transition section, and the inner lining 9 of the discharge thermal shock section are also fixed by Y-shaped anchor nails 302. The high-temperature main calcination section is constructed in a ring using chromium corundum composite bricks 701. The circumferential bricks are joined by the protruding inlay part 702 and the recessed inlay part 703 on the side. The axially adjacent chromium corundum composite bricks 701 are joined by the protruding inlay part 704 and the recessed inlay part 705 on the end face. The whole structure adopts a staggered arrangement to ensure that the masonry is tight and there are no straight gaps.

[0060] Step 5: After each section of the lining structure has completely cured and dried, uniformly spray a high-temperature resistant and salt-corrosion-resistant protective coating on all exposed surfaces of the inner layers of the lining 6 in the feeding flushing section, the lining 7 in the high-temperature calcination section, the lining 8 in the intermediate transition section, and the lining 9 in the discharge thermal shock section, completely covering the brick body, the surface of the castable, and the gaps between the bricks; after spraying, perform room temperature curing and low-temperature kiln drying gradient treatment to eliminate the moisture inside the lining, and finally complete the construction of the overall lining structure.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A corrosion-resistant and thermal shock-resistant refractory lining structure for a hazardous waste rotary kiln, characterized in that: The device includes an outer shell body (1), a buffer interlayer (2), an inner shell mechanism (3), and a high-temperature calcination section lining (7). The inner side of the outer shell body (1) is fitted with a buffer interlayer (2), and the inner side of the buffer interlayer (2) is fitted with an inner shell mechanism (3). The inner shell mechanism (3) includes an inner shell body (301). Multiple Y-shaped anchors (302) are welded to the inner side of the inner shell body (301). An outer strip groove (303) is opened on the outer side of the inner shell body (301), and an inner strip groove (304) is opened on the inner side of the inner shell body (301). The inner shell mechanism (3) is built with an elastic buffer leveling layer (4), and the inner side of the elastic buffer leveling layer (4) is built with a composite heat insulation layer (5). The inner side of the composite heat insulation layer (5) is divided into a feeding flushing section, a high-temperature main calcination section, an intermediate transition section and a discharge thermal shock section according to the difference in axial working conditions of the kiln body. The feeding flushing section is lined with a feeding flushing section lining (6), the high-temperature main calcination section is lined with a high-temperature calcination section lining (7), the high-temperature calcination section lining (7) is constructed from multiple chromium corundum composite bricks (701), one side of the chromium corundum composite brick (701) is integrally formed with a side protruding inlay part (702), the other side is integrally formed with a side recessed inlay part (703), one end of the chromium corundum composite brick (701) is integrally formed with an end face protruding inlay part (704), the other end is integrally formed with an end face recessed inlay part (705), the intermediate transition section is lined with an intermediate transition section lining (8), and the discharge thermal shock section is lined with a discharge thermal shock section lining (9). The outer shell body (1) is made of carbon structural steel plate, the inner shell body (301) is made of heat-resistant stainless steel plate, the outer side and inner side of the buffer interlayer (2) are welded and fixed to the outer shell body (1) and the inner shell body (301) respectively, the buffer interlayer (2) is made of heat-resistant austenitic stainless steel, and the cross section of the buffer interlayer (2) is in the shape of multiple circumferentially arranged X-shapes. The buffer interlayer (2) is used to reduce the heat transfer between the inner shell body (301) and the outer shell body (1), and to provide space for thermal expansion and contraction of the inner shell body (301). The inner lining (6) of the feed flushing section and the inner lining (8) of the intermediate transition section are both cast from chromium corundum castable SD-19B, with no masonry gaps, and can resist the high-speed flushing of materials and the slight corrosion of flue gas with high strength. The discharge thermal shock section lining (9) is cast from corundum mullite castable SD-180 to adapt to the harsh working conditions of frequent hot and cold alternation at the discharge end. The inner surfaces of the feed flushing section lining (6), the high temperature calcination section lining (7), the intermediate transition section lining (8), and the discharge thermal shock section lining (9) are uniformly sprayed with a high temperature resistant and salt corrosion resistant protective coating. The protective coating completely covers the exposed surfaces of the brick and the castable material, and is used to isolate the molten salt and acid and alkali corrosive flue gas generated by the incineration of hazardous waste, and to slow down the lining corrosion rate.

2. The erosion-resistant and thermal shock-resistant refractory lining structure for hazardous waste rotary kilns according to claim 1, characterized in that, Both the outer strip groove (303) and the inner strip groove (304) are axially slotted, and the outer strip groove (303) and the inner strip groove (304) are circumferentially staggered to release the stress of thermal expansion and contraction and provide expansion margin for the inner shell body (301).

3. The erosion-resistant and thermal shock-resistant refractory lining structure for hazardous waste rotary kilns according to claim 1, characterized in that, The elastic buffer leveling layer (4) is composed of high-temperature plastic refractory mortar and elastic refractory fiber felt. The elastic buffer leveling layer (4) is set close to the inner wall of the inner shell body (301) to offset the thermal expansion and contraction deformation of the kiln body, level the installation base surface and block the transmission of hard stress between layers.

4. The erosion-resistant and thermal shock-resistant refractory lining structure for hazardous waste rotary kilns according to claim 1, characterized in that, The composite heat insulation layer (5) is formed by composite casting of heat insulation castable SD-1.0 and outer heat insulation and wear-resistant castable SD-NC03. The discharge end is thickened and a multi-layer heat insulation structure is set. The heat insulation layer is firmly attached and fixed by Y-type anchor nails (302), and has both low thermal conductivity heat insulation and flue gas blocking performance.

5. The erosion-resistant and thermal shock-resistant refractory lining structure for hazardous waste rotary kilns according to claim 1, characterized in that, The chromium corundum composite bricks (701) are laid in a ring along the inner wall of the composite heat insulation layer (5). Two circumferentially adjacent chromium corundum composite bricks (701) are interlocked by the side protruding inlay part (702) and the side recessed inlay part (703). The axially adjacent chromium corundum composite bricks (701) are interlocked by the end face protruding inlay part (704) and the end face recessed inlay part (705). The axially adjacent chromium corundum composite bricks (701) adopt a staggered arrangement structure.

6. A method for constructing an erosion-resistant and thermal shock-resistant refractory lining structure for a hazardous waste rotary kiln, applicable to an erosion-resistant and thermal shock-resistant refractory lining structure for a hazardous waste rotary kiln according to any one of claims 1-5, characterized in that... The specific steps include the following: Step 1: Remove rust and oil stains from the inner working surface of the outer shell body (1) and grind it to ensure that the welding base surface is flat and clean; weld the outer side of the heat-resistant austenitic stainless steel buffer interlayer (2) with X-shaped cross section and circumferential arrangement to the corresponding position of the inner side of the outer shell body (1) to ensure that each X-shaped structure is evenly arranged and without deformation, and reserve the thermal expansion deformation allowance; then weld the outer side of the inner shell body (301) to the inner side of the buffer interlayer (2) to complete the overall assembly of the inner and outer shells; Step 2: Open an outer strip groove (303) on the outer side of the inner shell body (301) and an inner strip groove (304) on the inner side to ensure that the two types of grooves are staggered in the circumferential direction; weld and fix multiple Y-shaped anchor nails (302) evenly on the inner side of the inner shell body (301). Step 3: First, lay a composite elastic buffer leveling layer (4) on the inner wall of the inner shell body (301), and form a mechanical fit with the inner strip groove (304) to flatten the lining base surface and offset the shell deformation stress; after the leveling layer is cured, pour SD-1.0 heat insulation castable and SD-NC03 heat insulation and wear-resistant castable in layers to form an overall composite heat insulation layer (5). Thicken the pouring multi-layer heat insulation structure at the discharge end, and rely on Y-type anchor nails (302) for hanging and shaping throughout the process, and cure until the strength meets the standard; Step 4: According to the axial working conditions of the kiln body, the feeding flushing section and the intermediate transition section are integrally cast using SD-19B chromium corundum castable to form the inner lining (6) of the feeding flushing section and the inner lining (8) of the intermediate transition section respectively; the discharge thermal shock section is cast using SD-180 corundum mullite castable to form the inner lining (9) of the discharge thermal shock section. The inner lining (6) of the feeding flushing section, the inner lining (8) of the intermediate transition section and the inner lining (9) of the discharge thermal shock section are also fixed by Y-type anchor nails (302); the high-temperature main calcination section is constructed in a ring using chromium corundum composite bricks (701). The circumferential bricks are joined by the side protruding inlay part (702) and the side recessed inlay part (703). The axial bricks are fitted by the end face protruding inlay part (704) and the end face recessed inlay part (705). The whole structure adopts a staggered arrangement to ensure that the masonry is tight and there are no straight gaps. Step 5: After the inner lining structure of each section has been completely cured and dried, a high-temperature resistant and salt-corrosion resistant protective coating is evenly sprayed on all exposed surfaces of the inner layers of the inner lining of the feeding flushing section (6), the high-temperature calcination section (7), the intermediate transition section (8), and the discharge thermal shock section (9), completely covering the brick body, the surface of the castable and the gaps between the bricks; after the spraying is completed, room temperature curing and low temperature kiln drying gradient treatment are carried out to eliminate the moisture inside the lining, and finally the construction of the overall lining structure is completed.

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