Heat insulation and energy saving method for rotary kiln

Abstract

The invention discloses a thermal insulation and energy saving method for a rotary kiln, which is characterized in that a light thermal vibration protective coating for a carrier rocket is applied to the outside of the rotary kiln for the first time, and a coating process is continuously explored and optimized, and the method comprises the following steps: surface cleaning, sand blasting, primer spraying, intermediate paint spraying and finish paint coating. The method has the advantages that the heat loss of the rotary kiln is effectively reduced, the utilization efficiency of energy is remarkably improved, the thermal stress of the rotary kiln caused by drastic temperature change is effectively relieved, the maintenance period is prolonged, the production cost is reduced, and energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] This invention relates to the field of rotary kiln technology, and in particular to a method for heat insulation and energy saving of rotary kilns. Background Technology

[0002] Rotary kilns, as core thermal equipment in key industries such as metallurgy, chemicals, and building materials, typically maintain a surface temperature between 80-230℃ during continuous operation. A significant amount of heat is continuously lost through the kiln surface into the surrounding environment, leading to excessively high ambient temperatures. This poses a potential threat to on-site operators and surrounding equipment and instruments, and also results in severe energy waste and a substantial increase in production costs. Currently, the insulation measures used for rotary kilns mainly involve wrapping them with traditional insulation materials such as rock wool and glass wool, which suffer from poor insulation performance and short service life. Therefore, developing a new rotary kiln insulation technology with high-efficiency thermal insulation performance and ultra-long durability has become a critical challenge that urgently needs to be overcome in the current industrial field. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a heat insulation and energy-saving method for rotary kilns with good heat insulation effect and long maintenance cycle.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is a method for heat insulation and energy saving of a rotary kiln, comprising the following steps: S1. Surface cleaning: Clean the external surface of the rotary kiln to remove impurities adhering to the surface; S2. Sandblasting treatment: Sandblasting treatment of the surface of the rotary kiln; S3. Apply primer: Spray a layer of high-temperature resistant primer on the surface of the rotary kiln. The dry film thickness of the primer is 50μm-80μm; dry and cure at room temperature for 2-4 hours. S4. Spraying intermediate paint: After the primer is completely dry and cured, spray intermediate paint on the primer surface. The dry film thickness of intermediate paint is 80μm-120μm. After the intermediate paint is sprayed, put the rotary kiln into an oven at 60℃-80℃ and dry it for 1h-2h. S5. Applying the topcoat: After the intermediate coat has dried and cooled to room temperature, apply a layer of topcoat evenly to the surface of the intermediate coat. The thickness of this topcoat should be 1mm-1.5mm. When applying the topcoat, the angle between the scraper and the surface should be 30-45 degrees. Then, spray another layer of topcoat onto the surface and precisely adjust the thickness and smoothness of the topcoat to achieve a total thickness of 2mm-3mm. After the topcoat is applied, allow it to dry naturally at room temperature for 7-10 days.

[0005] The topcoat used in step S5 is a lightweight thermal shock protective coating for launch vehicles developed by Zhoushan Tengyu Aerospace New Materials Co., Ltd. This coating has an extremely low thermal conductivity, ≤0.05W / (m·K) at a standard ambient temperature of 25℃. Excellent high-temperature resistance is another significant advantage of this coating. It can operate stably for extended periods in high-temperature environments above 600℃ without any performance degradation. The coating exhibits excellent heat radiation reflectivity, with a reflectivity ≥85%. The primer and intermediate coat in steps S3 and S4 are primers and intermediate coats designed to complement the lightweight thermal shock protective coating for launch vehicles.

[0006] Furthermore, the specific method of sandblasting in step S2 is as follows: using quartz sand with a particle size of 80-120 mesh, and using compressed air of 0.5-0.8MPa to drive the quartz sand to impact the surface of the rotary kiln at high speed for 20-40 minutes, so that the surface roughness of the rotary kiln reaches Ra 6.3 - Ra 12.5μm.

[0007] Furthermore, in step S3 (spraying the primer) and step S4 (spraying the intermediate coat), the pressure of the spray gun is 0.3-0.5 MPa, the distance between the spray gun and the rotary kiln surface is 200-300 mm, and the spray gun moving speed is 10-15 meters per minute. Furthermore, in step S5, when spraying the topcoat, the pressure of the spray gun is 0.4-0.6 MPa, and the distance between the spray gun and the surface of the rotary kiln is 250 mm-350 mm.

[0008] Furthermore, after applying the topcoat in step S5, the process also includes step S6: attaching an insulation layer: attaching an insulation layer to the surface of the topcoat. The insulation layer can be a ZS-1071, JXGW-140, or JXGW-160 series water-based adhesive.

[0009] Furthermore, the insulation layer is made of aluminum silicate fiberboard.

[0010] Furthermore, after step S6, an erosion-resistant surface layer is also included: a layer of high-temperature resistant adhesive is sprayed onto the surface of the insulation layer, cured at room temperature for 24 hours after spraying, and then the temperature is increased in stages, by 50°C per hour, to promote the crystallization of the high-temperature resistant adhesive to form a dense protective layer. The high-temperature resistant adhesive is model HLGX-26. The function of the erosion-resistant surface layer is that the dense protective layer formed by the crystallization of the high-temperature resistant adhesive after sintering can withstand high-speed airflow of 80–90 m / s, prevent rainwater from penetrating into the insulation layer, and avoid the insulation layer from peeling off due to the vaporization of moisture caused by heat. Additives such as molybdenum disulfide can be added to the high-temperature resistant adhesive to enhance the hardness and wear resistance of the erosion-resistant surface layer.

[0011] Furthermore, the dry film thickness of the high-temperature resistant adhesive is 1mm-3mm.

[0012] Furthermore, the surface cleaning method in step S1 is as follows: use a high-pressure water gun to rinse the surface of the rotary kiln with a water pressure of 5-8 MPa to thoroughly remove dust, oil and other impurities from the surface.

[0013] Furthermore, the topcoat used in step S5 contains 0.5%-1.5% of a dispersant by weight and 0.3%-0.8% of a leveling agent by weight.

[0014] Beneficial effects of this invention: This invention is the first to apply lightweight thermal shock protection coating for launch vehicles to the exterior of a rotary kiln. Through continuous exploration and optimization of the coating process, it effectively reduces heat loss in the rotary kiln, significantly improves energy utilization efficiency, effectively alleviates thermal stress caused by drastic temperature changes, greatly reduces thermal fatigue damage to the equipment, extends the maintenance cycle of the rotary kiln to more than 24 months, reduces downtime caused by equipment maintenance, and improves the reliability and service life of the equipment, providing a strong guarantee for continuous and stable production.

[0015] Furthermore, significant energy conservation and emission reduction achievements have been made: the surface temperature of the rotary kiln has been reduced by 15-25°C. Statistical analysis of extensive actual test data shows that fuel consumption can be reduced by 10-15% under the same production conditions. This not only means a substantial reduction in energy procurement costs for enterprises, but more importantly, it significantly reduces emissions of various pollutants generated from fuel combustion, such as carbon dioxide, sulfur dioxide, and nitrogen oxides, making a positive contribution to environmental protection and demonstrating significant environmental benefits. Detailed Implementation

[0016] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] Example 1 A method for heat insulation and energy saving of a rotary kiln includes the following steps: S1. Surface cleaning: Clean the external surface of the rotary kiln to remove impurities adhering to the surface; S2. Sandblasting treatment: Sandblasting treatment of the surface of the rotary kiln; S3. Apply primer: Spray a layer of high-temperature resistant primer on the surface of the rotary kiln. The dry film thickness of the primer is 50μm-80μm; dry and cure at room temperature for 2-4 hours. S4. Spraying intermediate paint: After the primer is completely dry and cured, spray intermediate paint on the primer surface. The dry film thickness of intermediate paint is 80μm-120μm. After the intermediate paint is sprayed, put the rotary kiln into an oven at 60℃-80℃ and dry it for 1h-2h. S5. Applying the topcoat: After the intermediate coat has dried and cooled to room temperature, apply a layer of topcoat evenly to the surface of the intermediate coat. The thickness of this topcoat should be 1mm-1.5mm. When applying the topcoat, the angle between the scraper and the surface should be 30-45 degrees. Then, spray another layer of topcoat onto the surface and precisely adjust the thickness and smoothness of the topcoat to achieve a total thickness of 2mm-3mm. After the topcoat is applied, allow it to dry naturally at room temperature for 7-10 days.

[0018] The topcoat used in step S5 is a lightweight thermal shock protective coating for launch vehicles developed by Zhoushan Tengyu Aerospace New Materials Co., Ltd. This coating has an extremely low thermal conductivity, ≤0.05W / (m·K) at a standard ambient temperature of 25℃. Excellent high-temperature resistance is another significant advantage of this coating. It can operate stably for extended periods in high-temperature environments above 600℃ without any performance degradation. The coating exhibits excellent heat radiation reflectivity, with a reflectivity ≥85%. The primer and intermediate coat in steps S3 and S4 are primers and intermediate coats designed to complement the lightweight thermal shock protective coating for launch vehicles.

[0019] Furthermore, the specific method of sandblasting in step S2 is as follows: using quartz sand with a particle size of 80-120 mesh, and using compressed air of 0.5-0.8MPa to drive the quartz sand to impact the surface of the rotary kiln at high speed for 20-40 minutes, so that the surface roughness of the rotary kiln reaches Ra 6.3 - Ra 12.5μm.

[0020] Furthermore, in step S3 (spraying the primer) and step S4 (spraying the intermediate coat), the pressure of the spray gun is 0.3-0.5 MPa, the distance between the spray gun and the rotary kiln surface is 200-300 mm, and the spray gun moving speed is 10-15 meters per minute. Furthermore, in step S5, when spraying the topcoat, the pressure of the spray gun is 0.4-0.6 MPa, and the distance between the spray gun and the surface of the rotary kiln is 250 mm-350 mm.

[0021] Furthermore, the surface cleaning method in step S1 is as follows: use a high-pressure water gun to rinse the surface of the rotary kiln with a water pressure of 5-8 MPa to thoroughly remove dust, oil and other impurities from the surface.

[0022] Furthermore, the topcoat used in step S5 contains 0.5%-1.5% of a dispersant by weight and 0.3%-0.8% of a leveling agent by weight.

[0023] Example 2 Based on Example 1, an insulation layer and an erosion-resistant surface layer are added. Specifically, after applying the topcoat in step S5, step S6, the insulation layer is attached: an insulation layer is attached to the surface of the topcoat.

[0024] The insulation layer is made of aluminum silicate fiberboard.

[0025] Following step S6, an erosion-resistant surface layer is also provided: a layer of high-temperature resistant adhesive is sprayed onto the surface of the insulation layer, cured at room temperature for 24 hours after spraying, and then the temperature is increased in stages at 50°C per hour to promote the crystallization of the high-temperature resistant adhesive to form a dense protective layer. The dry film thickness of the high-temperature resistant adhesive is 1mm-3mm.

[0026] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for heat insulation and energy saving of a rotary kiln, characterized in that: Includes the following steps: S1. Surface cleaning: Clean the external surface of the rotary kiln to remove impurities adhering to the surface; S2. Sandblasting treatment: Sandblasting treatment of the surface of the rotary kiln; S3. Apply primer: Spray a layer of high-temperature resistant primer on the surface of the rotary kiln. The dry film thickness of the primer is 50μm-80μm; dry and cure at room temperature for 2-4 hours. S4. Spraying intermediate paint: After the primer is completely dry and cured, spray intermediate paint on the primer surface. The dry film thickness of intermediate paint is 80μm-120μm. After the intermediate paint is sprayed, put the rotary kiln into an oven at 60℃-80℃ and dry it for 1h-2h. S5. Applying the topcoat: After the intermediate coat has dried and cooled to room temperature, apply a layer of topcoat evenly to the surface of the intermediate coat. The thickness of this topcoat should be 1mm-1.5mm. When applying the topcoat, the angle between the scraper and the surface should be 30-45 degrees. Then, spray another layer of topcoat onto the surface and precisely adjust the thickness and smoothness of the topcoat to achieve a total thickness of 2mm-3mm. After the topcoat is applied, allow it to dry naturally at room temperature for 7-10 days.

2. The heat insulation and energy-saving method for rotary kilns according to claim 1, characterized in that: The specific method for sandblasting in step S2 is as follows: using quartz sand with a particle size of 80-120 mesh, and using compressed air of 0.5-0.8MPa to drive the quartz sand to impact the surface of the rotary kiln at high speed for 20-40 minutes, so that the surface roughness of the rotary kiln reaches Ra 6.3 - Ra 12.5μm.

3. The heat insulation and energy-saving method for rotary kilns according to claim 1, characterized in that: When spraying the primer in step S3 and the intermediate coat in step S4, the pressure of the spray gun is 0.3-0.5MPa, the distance between the spray gun and the surface of the rotary kiln is 200-300mm, and the moving speed of the spray gun is 10-15 meters per minute.

4. The heat insulation and energy-saving method for rotary kilns according to claim 1, characterized in that: In step S5, when spraying the topcoat, the pressure of the spray gun is 0.4-0.6 MPa, and the distance between the spray gun and the surface of the rotary kiln is 250 mm-350 mm.

5. The heat insulation and energy-saving method for rotary kilns according to claim 1, characterized in that: After applying the topcoat in step S5, the process also includes step S6: attaching an insulation layer: attaching an insulation layer to the surface of the topcoat.

6. The heat insulation and energy-saving method for rotary kilns according to claim 5, characterized in that: The insulation layer is made of aluminum silicate fiberboard.

7. The heat insulation and energy-saving method for rotary kilns according to claim 6, characterized in that: Step S6 is followed by setting an anti-erosion surface layer: a layer of high-temperature resistant adhesive is sprayed onto the surface of the insulation layer, cured at room temperature for 24 hours after spraying, and then the temperature is increased in stages, with an increase of 50°C per hour, to promote the crystallization of the high-temperature resistant adhesive to form a dense protective layer.

8. The heat insulation and energy-saving method for rotary kilns according to claim 7, characterized in that: The dry film thickness of the high-temperature resistant adhesive is 1mm-3mm.

9. The heat insulation and energy-saving method for rotary kilns according to claim 1, characterized in that: The surface cleaning method in step S1 is as follows: use a high-pressure water gun to rinse the surface of the rotary kiln with a water pressure of 5-8 MPa.

10. The heat insulation and energy-saving method for a rotary kiln according to claim 1, characterized in that: The topcoat used in step S5 contains 0.5%-1.5% by weight of dispersant and 0.3%-0.8% by weight of leveling agent.