Foam metal-based anti-static air duct and manufacturing method and application thereof

Abstract

The invention discloses a foam metal-based anti-static air duct and a manufacturing method and application thereof, and belongs to the technical field of VOCs treatment. The manufacturing method comprises the following steps that firstly, powdery metal, a spherical pore-forming agent and an adhesive mixture are evenly mixed; putting the mixed material into an air pipe mold, and briquetting to obtain a tubular cold-pressed block; removing the pore forming agent in the cold pressing block; smoothing the inner surface; sintering the cold pressing block to obtain an air pipe body; the sintering temperature is 75-85% of the metal melting point; secondly, the outer surface of the air pipe body is coated with a resin mixture, a shell is formed after air drying, and the anti-static air pipe is obtained; the resin mixture comprises quaternary ammonium salt type cationic surface active agent modified carbon fibers, an anti-ultraviolet agent and resin. The anti-static air pipe based on the foam metal is used for conveying gas in VOCs treatment. The invention has the advantages of excellent anti-static effect, low material consumption, light weight, convenience in installation and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of VOCs treatment, and relates to an antistatic air duct, and in particular to a foam metal-based antistatic air duct and a manufacturing method and application thereof. Background Art

[0002] The air duct is a piping system designed for air delivery and distribution. In actual applications, due to the difference in temperature and humidity between the internal and external environments of the air duct, and the dust, particulate matter and other charged particles carried in the air flow come into contact, rub and collide with the inner wall of the air duct during the flow process, these activities will cause static electricity, resulting in uneven distribution of charges on the surface of the air duct. When these accumulated charges reach a certain level and begin to move, static discharge will occur.

[0003] Static electricity discharge can cause a series of hazards. For example, in the process of VOCs treatment, if there are VOCs with low explosion limits such as benzene, toluene, acetone, and combustible gases in the conveying gas, the static electricity sparks generated by static electricity discharge may cause fire or explosion, thereby damaging the equipment and increasing the equipment maintenance cost; static electricity in the air duct will cause a static electricity field inside the air duct, and charged particles such as dust or other tiny particles will settle inside the air duct, resulting in increased wind resistance or blockage of the pipeline; at the same time, the accumulation of static electricity in the air duct will cause discharge when the operator touches it, posing a serious threat to human health and life safety.

[0004] With the continuous improvement of industrial safety standards, especially in industries that handle flammable and explosive gases and dust, the demand for anti-static air ducts is growing. However, some disadvantages of anti-static air ducts in practical applications, such as instability of anti-static effect, easy wear of coatings, poor grounding, etc., limit their wider application.

[0005] Specifically, the disadvantages of the current anti-static air ducts mainly include: easy to wear: when conveying explosion-proof dust, the anti-static air duct is subjected to greater pressure and impact, and its manufacturing materials are usually fragile, prone to cracking, deformation and other problems during long-term use, and need to be replaced regularly; limited anti-static methods: in order to eliminate static electricity, the inside of the existing anti-static air duct usually needs to be coated with a layer of conductive compound, but according to the "DB32 / T4700-2024 Safety Technical Requirements for Regenerative Thermal Incinerator Systems" standard, it is prohibited to apply non-conductive anti-corrosion coatings on the inner wall of the air duct. This regulation actually limits the coating selection of anti-static air ducts, and also causes some existing anti-static air ducts to fail to meet the safety technical specifications. Summary of the invention

[0006] The invention provides a foam metal-based antistatic air duct and a manufacturing method and application thereof, so as to overcome the defects of the prior art.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The invention discloses a method for manufacturing a foam metal-based antistatic air duct, comprising the following steps: step 1, uniformly mixing powdered metal, spherical pore-forming agent and bonding mixture; placing the mixed material into an air duct mold, pressing blocks to obtain tubular cold-pressed blocks; removing the pore-forming agent in the cold-pressed blocks; then smoothing the inner surface; sintering the cold-pressed blocks to obtain an air duct body; the sintering temperature is 75-85% of the melting point of the metal; step 2, applying a resin mixture on the outer surface of the air duct body, and forming an outer shell after drying to obtain the antistatic air duct; the resin mixture comprises modified carbon fiber modified by a quaternary ammonium salt type cationic surfactant, an anti-ultraviolet agent and a resin.

[0009] To optimize the above technical solutions, the specific measures taken also include:

[0010] Furthermore, in step 1, the volume ratio of the metal to the pore-forming agent is 1:0.6-0.8, and the volume ratio of the adhesive mixture to the metal and the pore-forming agent is 0.5-2:10; the metal is copper, iron or aluminum; the pore-forming agent is NaCl or Na2S2O3·5H2O; and the adhesive mixture is ethanol.

[0011] Furthermore, in step 1, the metal, pore-forming agent and adhesive mixture are mixed in the following manner: first, the metal and the pore-forming agent are mixed evenly, and then the adhesive mixture is added and mixed evenly.

[0012] Furthermore, in step 1, the pressure for briquetting is 400-500 MPa; the method for removing the pore-forming agent in the cold-pressed block is: immersing the cold-pressed block in water at 70-80°C for 5 hours, changing the water every half an hour for the first two hours, and changing the water every hour for the next three hours, to completely remove the pore-forming agent. The method for smoothing the inner surface is: applying powdered metal on the inner surface of the tubular cold-pressed block to make it smooth.

[0013] Furthermore, in step one, the specific method of sintering is: sintering in a standard hydrogen gas atmosphere in nitrogen; first heating to 100°C at a rate of 5°C / min, and then keeping warm for 40 to 50 minutes to remove moisture remaining in the cold pressed block after the water bath; then heating to the sintering temperature at a rate of 8°C / min, keeping warm for 2 to 4 hours; air cooling to obtain the duct body.

[0014] Furthermore, after obtaining the air duct body, the air duct body is first trimmed and then coated with the resin mixture; the trimming method is: first trimming the detail burrs of the air duct body; then grinding the inner and outer surfaces of the air duct body with sandpaper to make it flat and smooth.

[0015] Furthermore, in step 2, the preparation method of the modified carbon fiber is: mixing the carbon fiber with a quaternary ammonium salt type cationic surfactant to obtain the modified carbon fiber; the quaternary ammonium salt type cationic surfactant is benzalkonium chloride, benzalkonium bromide or dioctadecyl dimethyl ammonium chloride; the mass ratio of the carbon fiber to the quaternary ammonium salt type cationic surfactant is 5-10:2-4; in the resin mixture, the mass ratio of the modified carbon fiber, the anti-ultraviolet agent and the resin is 5-10:1-3:40-100; the anti-ultraviolet agent is TiO2, and the resin is an epoxy resin or a phenolic resin.

[0016] Furthermore, in step 2, the method of applying the resin mixture on the outer surface of the air duct body is: at a rate of 0.3-1 kg / m 2 Apply 1 to 2 layers of resin mixture evenly on the outer surface of the duct body.

[0017] The present invention also provides a foam metal-based antistatic air duct made by the above-mentioned manufacturing method.

[0018] The present invention also provides the use of the above-mentioned foam metal-based antistatic air duct for conveying gas in VOCs treatment.

[0019] The beneficial effects of the present invention are:

[0020] 1. The present invention uses foam metal as the base material to manufacture the anti-static air duct. Firstly, since the metal material itself has good conductivity, it can ensure that the air duct has a good anti-static effect; secondly, the foam metal has a polyhedral honeycomb structure, which can increase the contact area between the air duct and the environment, and its own large specific surface area is conducive to static electricity conduction, thereby further improving the anti-static effect and effectively preventing the potential harm caused by static electricity accumulation.

[0021] 2. Compared with solid metal materials, foam metal can greatly reduce the consumption of metal materials. Without affecting the strength and performance of the air duct, it significantly reduces the amount of metal used, thereby achieving resource conservation and cost reduction.

[0022] 3. The loose structure of the foam metal substrate not only reduces the material consumption, but also greatly reduces the overall weight of the air duct. This not only reduces the difficulty during transportation and installation, but also improves the convenience of equipment installation. This advantage is particularly significant in large-scale projects or occasions that require frequent replacement and maintenance.

[0023] 4. The reduction reaction between the metal inside the air duct and the VOCs in the exhaust gas can effectively prevent the foam metal from being oxidized and restore the anti-static performance.

[0024] 5. The outside of the air duct is covered with UV-proof resin material to form a fiberglass UV-proof shell, which serves as a protective layer to improve the durability of the air duct while enhancing its strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a flow chart of the method for making a foam metal-based antistatic air duct. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] This embodiment provides a foam metal-based antistatic air duct, and its manufacturing method is as follows: Figure 1 As shown, the following steps are included:

[0028] 1. Foam metal duct molding.

[0029] 1.1 Raw material assembly

[0030] Iron powder and spherical pore former Na2S2O3·5H2O were weighed at a volume ratio of 1:0.7 and mixed evenly to form a raw material mixture, with the proportion of the pore former being approximately equal to the porosity. Ethanol was then added as a binder and a mixing agent to make the raw material mixture more evenly mixed and ensure that the surface of the spherical pore former was evenly coated with iron powder. The volume ratio of ethanol to the raw material mixture was 1:10.

[0031] 1.2 Cold pressed blocks preparation

[0032] The uniformly mixed materials are placed in a duct mold and pressed into blocks at a pressure of 460 MPa to obtain cold pressed blocks.

[0033] Soak the cold pressed blocks in a 75°C water bath for 5 hours, changing the water every half an hour for the first two hours and once an hour for the next three hours to completely remove the pore-forming agent.

[0034] Apply metal powder to the inside of the formed duct to ensure a smooth internal surface.

[0035] 1.3 Duct sintering

[0036] The treated cold pressed block is placed in a tubular furnace and introduced with standard gas of hydrogen in nitrogen to prevent metal oxidation. The furnace temperature is raised to 100°C at a rate of 5°C / min and kept at this temperature for 40 minutes to remove residual moisture. After that, the temperature is raised to the preset temperature of 1100°C (about 80% of the melting point of the metal) at a rate of 8°C / min and kept at this temperature for 3 hours, and finally cooled naturally to obtain the foam metal-based duct body.

[0037] 2. Repair of the air duct body

[0038] Finely trim the tiny burrs on the surface of the air duct body. Use sandpaper to grind the inner and outer walls of the air duct body to ensure that the entire pipe is flat and smooth.

[0039] 3. Foam metal duct shell

[0040] Weigh 8 parts of carbon fiber and 3 parts of quaternary ammonium salt type cationic surfactant, mix and modify to obtain modified carbon fiber. Weigh 5 parts of modified carbon fiber, 1 part of anti-ultraviolet agent TiO2 and 40 parts of epoxy resin, stir and mix thoroughly to synthesize resin mixture. 2 Apply the resin mixture evenly on the outside of the air duct in 1 to 2 layers, and after drying, form a fiberglass UV-resistant shell to enhance the overall structural strength of the air duct.

[0041] The shell of the duct is made of resin to ensure the strength of the duct shell. Low resistivity carbon fiber is added as an antistatic agent and TiO2 is added as an anti-ultraviolet agent to enhance the antistatic and outdoor durability of the duct shell. In order to ensure uniform dispersion of the carbon fiber, the carbon fiber is modified with a quaternary ammonium salt type cationic surfactant to achieve uniform distribution in the shell preparation.

[0042] This embodiment also provides the application of the foam metal-based anti-static air duct in conveying gas in VOCs treatment, and the relevant performance tests are as follows:

[0043] Antistatic performance test: The antistatic performance test method refers to the method recorded in SJT 10694-2006, and the surface resistance is tested using a surface impedance tester 800. The measured surface resistance of the air duct is 5.6×105Ω, and the surface resistance of the outer surface is 6.8×105Ω. It can meet the requirements of the standards "MT 181-1988 Safety Performance Inspection Specification for Plastic Pipes Used in Coal Mines" and "MT 558.3-2005 Plastic Pipes Used in Coal Mines Part 3: Glass Fiber Reinforced Plastic Pipes". The positive pressure air duct does not exceed 106Ω, and the negative pressure air duct does not exceed 108Ω.

[0044] Mechanical strength test: The test parameters include bending strength and tensile strength. The test method refers to the methods described in GB / T1447-2005, GB / T1448-2005 and GB / T1449-2005. The measured bending strength can reach 201 and the tensile strength can reach 249, indicating that the anti-static air duct has good strength.

[0045] Anti-ultraviolet aging performance test: The anti-static air duct is exposed to ultraviolet light for 700 hours, and the ultraviolet light intensity is 0.9J / m 2 , specifically referring to the method described in GB / T1043-2008, the impact strength of the anti-static air duct before and after ultraviolet irradiation was tested, and the change rate of the impact strength was calculated. The test results show that after ultraviolet irradiation, the impact strength change rate is about 3.9%, which has good ultraviolet resistance.

[0046] Specific surface area test: The BET specific surface area test of the foam metal material of the anti-static air duct was carried out, and its specific surface area was about 37.8cm 2 / cm 3 , which can effectively increase the contact area between the air duct and the environment, and is conducive to the discharge of static electricity.

[0047] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. In addition, the reagents, materials and operating procedures used herein are reagents, materials and conventional procedures widely used in the corresponding fields.

[0048] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0049] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a foam metal-based anti-static air duct, characterized in that: The following steps are involved: Step 1: Evenly mix the powdered metal, spherical pore-forming agent and bonding agent; The mixed material is placed in a duct mold and pressed into a block to obtain a tubular cold pressed block; the pore-forming agent in the cold pressed block is removed; and the inner surface is smoothed; The cold pressed block is sintered to obtain the air duct body; the sintering temperature is 75-85% of the melting point of the metal; Step 2: Apply a resin mixture on the outer surface of the duct body, and form an outer shell after drying to obtain an antistatic duct; the resin mixture includes modified carbon fiber modified by a quaternary ammonium salt type cationic surfactant, an anti-ultraviolet agent and a resin.

2. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: In step 1, the volume ratio of the metal to the pore-forming agent is 1:0.6-0.8, and the volume ratio of the bonding agent to the metal and the pore-forming agent is 0.5-2:10; The metal is copper, iron or aluminum; The pore former is NaCl or Na2S2O3·5H2O; The bonding agent is ethanol.

3. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: In step 1, the metal, pore-forming agent and adhesive mixture are mixed in the following manner: first, the metal and the pore-forming agent are mixed evenly, and then the adhesive mixture is added and mixed evenly.

4. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: In step 1, the briquetting pressure is 400-500 MPa; The method for removing the pore-forming agent in the cold pressed block is as follows: immerse the cold pressed block in water at 70-80°C for 5 hours, change the water every half an hour for the first two hours, and change the water every hour for the next three hours to completely remove the pore-forming agent. The method for smoothing the inner surface is to apply powdered metal to the inner surface of the tubular cold pressed block to make it smooth.

5. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: In step one, the specific method of sintering is: sintering in a standard hydrogen gas atmosphere in nitrogen; first heating to 100°C at a rate of 5°C / min, and then keeping warm for 40 to 50 minutes; then heating to the sintering temperature at a rate of 8°C / min, keeping warm for 2 to 4 hours; air cooling to obtain the duct body.

6. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: After obtaining the air duct body, the air duct body is first trimmed and then the resin mixture is applied; The finishing method is: first trim the detailed burrs of the air duct body; then grind the inner and outer surfaces of the air duct body with sandpaper to make it flat and smooth.

7. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: In step 2, the modified carbon fiber is prepared by mixing the carbon fiber with a quaternary ammonium salt type cationic surfactant to obtain the modified carbon fiber; the quaternary ammonium salt type cationic surfactant is benzalkonium chloride, benzalkonium bromide or dioctadecyl dimethyl ammonium chloride; the mass ratio of the carbon fiber to the quaternary ammonium salt type cationic surfactant is 5-10:2-4; In the resin mixture, the mass ratio of the modified carbon fiber, the anti-ultraviolet agent and the resin is 5-10:1-3:40-100; the anti-ultraviolet agent is TiO2, and the resin is epoxy resin or phenolic resin.

8. The method for manufacturing a foam metal-based antistatic air duct according to claim 1, characterized in that: In step 2, the method of applying the resin mixture on the outer surface of the duct body is: 0.3-1kg / m 2 Apply 1 to 2 layers of resin mixture evenly on the outer surface of the duct body.

9. The antistatic air duct based on a foam metal obtained by the manufacturing method as described in any one of claims 1 to 8.

10. Use of the foam metal-based antistatic air duct as claimed in claim 9 for conveying gas in VOCs treatment.

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