Environment-friendly and efficient curing oven for precoated metal coil powder color coating

Abstract

The utility model is suitable for the technical field of precoated metal coiled material production, and provides an environment-friendly and efficient curing oven for precoated metal coiled material powder color coating, which comprises an oven body, an outer thermal insulation layer, a gas catalyst infrared catalysis plate and a hot air circulation system. The furnace body is provided with an inlet and an outlet, a sag meter is arranged at the inlet of the furnace body, an infrared thermometer is arranged at the outlet of the furnace body, a conveying channel is formed inside the furnace body, an outer heat preservation layer is arranged outside the furnace body, and the outer heat preservation layer is an aluminum silicate ceramic heat preservation layer; the gas catalyst infrared catalysis plates are connected side by side, and the hot air circulation system comprises a fan, an air pipe and an air bellow nozzle. The curing oven is safe, efficient, energy-saving, environment-friendly, accurate in temperature control and uniform in temperature distribution in the oven, so that a coating on the surface of a coiled material is cured more flatly and uniformly, and the curing oven can be well applied to curing of a coating on the surface of a large-area plate.

Description

Technical Field

[0001] The utility model relates to the technical field of pre-coated metal coil production, in particular to an environmentally friendly and efficient curing furnace for pre-coated metal coil powder color coating. Background Art

[0002] On the pre-coated metal coil coating production line, the drying and curing of the coating is generally completed by a curing furnace. Currently, the curing furnaces that can be used include gas heating curing furnaces, electromagnetic heating curing furnaces, infrared heating curing furnaces, ultraviolet curing, electron beam scanning curing, etc. The more mature and adopted ones are generally gas heating curing furnaces and electromagnetic heating curing furnaces. The gas heating furnace curing is mainly to preheat fresh air through a heat exchanger after natural gas combustion. The preheated air is sent into the curing furnace by a fan as a heat carrier to heat the substrate. The furnace body is generally divided into 3 to 5 sections. At the same time, this type of curing device is equipped with an exhaust gas fan. The exhaust gas fan draws the small molecular substances or low-boiling volatiles baked out of the coating from the heating furnace to a special incinerator to burn in the air to generate high-temperature heat, which is returned to the heating furnace; electromagnetic heating is mainly that the substrate is heated by the 104HZ high-frequency coil magnetic field, which generates eddy currents to heat the substrate, thereby curing the powder coating into a film. In addition, there is a gas curing furnace combined with an electromagnetic heating or infrared radiation furnace. However, since the combustion of natural gas will be mixed with air to produce some nitrogen oxide pollution, related equipment needs to be invested in to transform emissions, which increases equipment investment. In addition, due to the high temperature requirements for curing powder coatings, low electromagnetic heating efficiency, high power consumption, uneven curing of powder coatings, and prone to quality problems such as coating cracking, the color coating curing furnace for pre-coated metal coils needs to be explored in the direction of low energy consumption, low investment, environmental protection and high efficiency. Summary of the invention

[0003] In view of the above situation, the purpose of the utility model is to provide an environmentally friendly and efficient curing furnace for powder color coating of pre-coated metal coils. The curing furnace heats up quickly, the equipment occupies a small area, and no ignition is required. The combustible gas can generate medium-wave infrared radiation through the gas catalyst infrared catalytic plate. Catalytic combustion is an oxidation reaction, not a traditional ignition combustion, but the Tonghua catalyst catalytic layer combines the combustible gas with oxygen to produce an oxidation reaction, and the oxidation reaction is controlled to proceed on the outer surface of the catalytic layer. The oxidation reaction can reach a completely flameless state, so it is highly efficient, safe and reliable; the infrared radiation wavelength of the infrared wave system generated by the gas catalyst infrared catalytic plate is between 3.5 and 5.5 μm, which is completely matched with the absorption spectrum of the powder coating and water. Only the carboxyl and hydroxyl molecules in the coating are heated, and there is no obvious heating effect on the uncoated metal and air. All energy is concentrated and directly transferred to the coating, and the coating is cured from the inside out. It is safer, more efficient, energy-saving and environmentally friendly, and the temperature control is accurate. The temperature distribution in the furnace is uniform, so that the curing of the coil surface coating is more level and uniform, and it can be well applied to the curing of the surface coating of a large area of ​​plate.

[0004] In order to achieve the above-mentioned purpose, the utility model provides an environmentally friendly and efficient curing furnace for powder color coating of pre-coated metal coils, including: a furnace body, an outer insulation layer, a gas catalyst infrared catalytic plate, and a hot air circulation system. The furnace body is provided with an inlet and an outlet, a sag meter is provided at the inlet of the furnace body, an infrared thermometer is provided at the outlet, a conveying channel is provided inside, and an outer insulation layer is provided outside, the outer insulation layer is an aluminum silicate ceramic insulation layer, gas catalyst infrared catalytic plates are symmetrically installed on the upper and lower sides of the conveying channel inside the furnace body, the gas catalyst infrared catalytic plates are connected side by side with each other, and the hot air circulation system includes a fan, an air duct, and a bellows nozzle.

[0005] In the curing furnace for powder color coating of pre-coated metal coils as described above, the distance between the furnace body conveying channel and the gas catalyst infrared catalytic plates on the upper and lower sides of the furnace body is greater than 10 cm, and the length of the conveying channel is consistent with the length of the furnace body.

[0006] The curing furnace for powder color coating of pre-coated metal coils as described above, wherein the furnace body is a straight-through structure, the conveying channel is provided with a gas catalyst infrared catalytic plate and a hot air circulation system to provide infrared radiation heating and hot air circulation insulation respectively, and the length of the furnace body is set according to the length and speed of the production line.

[0007] In the curing furnace for powder color coating of pre-coated metal coil as described above, the bellows nozzle is connected to the air duct, one end of the air duct is connected to the bellows nozzle, and the other end is connected to the fan, and the bellows nozzle is arranged on both sides of the gas catalyst infrared catalytic plate.

[0008] The curing furnace for powder coating of pre-coated metal coils as described above, wherein the infrared radiation heating mainly adopts a modular design, each module adopts a symmetrical design, and is composed of independent gas catalyst infrared catalytic plates, the gas catalyst infrared catalytic plates are connected by bolts or rivets, the outer gas catalyst infrared catalytic plates can be disassembled separately, and the connection length of the gas catalyst infrared catalytic plate module can be adjusted according to the length of the production line.

[0009] As described above, in the curing furnace for powder color coating of pre-coated metal coils, the infrared radiation heating is controlled by gas pulses, and the gas catalyst infrared catalytic plate is provided with a solenoid valve and a pressure reducing valve, which can adjust the flow rate of gas on the gas catalyst infrared catalytic plate to control the energy transmission size, thereby controlling the radiation energy of the gas catalyst infrared catalytic plate and the furnace temperature.

[0010] In the curing furnace for powder color coating of pre-coated metal coils as described above, the gas catalyst infrared catalytic plate is in a rectangular structure, a metal panel is installed on the back, the metal panel is installed with a solenoid valve, a pressure reducing valve and a thermocouple, and a metal mesh cover is installed on the front.

[0011] Compared with the prior art, the advantages of the utility model are as follows:

[0012] The curing furnace for powder color coating of pre-coated metal coils provided by the utility model adopts a combination of infrared radiation heating and hot air circulation system insulation, and there is no need to separately set up infrared radiation heating and hot air circulation heating furnace bodies, so the equipment occupies a small area, and infrared radiation heating does not require ignition. Pulse control of gas is used to heat the infrared rays generated by the gas catalyst infrared catalytic plate, and the temperature rises rapidly. Combined with the insulation of the hot air circulation system, gas energy can be saved; moreover, the infrared radiation wavelength generated by the gas catalyst infrared catalytic plate is completely matched with the absorption spectrum of the powder coating and water, and only the carboxyl and hydroxyl molecules in the coating are heated. There is no obvious heating effect on uncoated metal and air. All energy is concentrated and directly transferred to the coating, and the coating is cured from the inside out. It is safer, more efficient, energy-saving and environmentally friendly, and the temperature control is accurate. The temperature distribution in the furnace is uniform, so that the curing of the coil surface coating is more level and uniform, and it can be well applied to the curing of large-area plate surface coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following drawings are only intended to illustrate and explain the present invention, and do not limit the scope of the present invention.

[0014] Figure 1 This is a schematic diagram of the layout and structure of a curing furnace for powder coating of pre-coated metal coils provided by the utility model;

[0015] Figure 2 This is a schematic diagram of the structure of the infrared catalytic plate of the gas catalyst provided by the utility model;

[0016] Figure 3 It is a schematic diagram of the furnace structure.

[0017] Explanation of the reference numerals: 1. Furnace body, 2. External insulation layer, 3. Gas catalyst infrared catalytic plate, 4. Hot air circulation system, 5. Sag meter, 6. Infrared thermometer, 7. Pre-coated metal coil;

[0018] Conveying channel, 301. solenoid valve, 302. pressure reducing valve, 303. thermocouple, 304. metal mesh cover, 305. riveted joint, 401. fan, 402. air duct, 403. bellows nozzle. DETAILED DESCRIPTION

[0019] In order to have a clearer understanding of the technical solution, purpose and effect of the utility model, the specific implementation mode of the utility model is now described in conjunction with the accompanying drawings.

[0020] like Figure 1 , Figure 2 and Figure 3 As shown, the utility model provides an environmentally friendly and efficient curing furnace for pre-coated metal coil powder color coating, wherein the curing furnace for pre-coated metal coil powder color coating includes: a furnace body 1, an outer insulation layer 2, a gas catalyst infrared catalytic plate 3, and a hot air circulation system 4.

[0021] like Figure 1 As shown, the furnace body 1 is a straight-through structure with a certain length, generally about 30 to 50 meters. The length of the furnace body 1 can be set according to the production speed of the pre-coated metal coil 7. The furnace body 1 is provided with an inlet and an outlet. A sag meter 5 is provided at the inlet of the furnace body, which can effectively prevent the pre-coated metal coil 7 from touching the furnace body and causing surface scratches during transportation. An infrared thermometer 6 is provided at the outlet of the furnace body, which can monitor the surface curing coating temperature of the pre-coated metal coil 7 online, obtain the average temperature value of the pre-coated metal coil 7 after curing, and transmit it back to the temperature control system to control the temperature of the furnace body 1. A conveying channel 101 is provided inside the furnace body 1. The length of the conveying channel 101 is consistent with the length of the furnace body 1. The conveying channel 101 should preferably be kept at a distance of more than 20 cm from the upper and lower surfaces of the furnace body 1 to ensure that the pre-coated metal coil 7 is safely transported in the air in the furnace body 1. The adjustment of the safety distance is adjusted by setting the sag meter 5 to adjust the sag of the pre-coated metal coil 7 during the transportation process, as shown in FIG. Figure 3 As shown, an outer thermal insulation layer 2 is provided outside the furnace body 1. The outer thermal insulation layer 2 is an aluminum silicate ceramic thermal insulation layer, which can effectively insulate and prevent heat from dissipating outward.

[0022] Furthermore, the conveying channel 101 of the furnace body 1 is provided with a gas catalyst infrared catalytic plate 3 and a hot air circulation system 4 to provide infrared radiation heating and hot air circulation insulation respectively. The infrared radiation heating principle is that natural gas is catalyzed by a platinum catalyst to produce a flameless oxidation reaction, oxygen is introduced, and then electrically heated, and then natural gas is introduced and electrically heated continuously. After reaching a certain temperature, the electric heating is stopped to cause an oxidation reaction. After the reaction, carbon dioxide and water are produced and an infrared radiation source is formed, generating diffusely reflected light waves, which can be reflected on the surface coating of the pre-coated metal coil 7. The light wave frequency of the infrared radiation source corresponds to the absorption band of the coating, causing the powder coating molecules to resonate and produce molecular bond vibration friction, the powder quickly heats up and melts, and rapid solidification is achieved. While the powder heats up, it continuously conducts heat to the surface coating of the pre-coated metal coil 7, and the heat is conducted and diffused inside the surface coating of the pre-coated metal coil 7. The infrared radiation heating mainly adopts a modular design. Each module adopts a symmetrical design and is composed of independent gas catalyst infrared catalytic plates 3. The gas catalyst infrared catalytic plates 3 are connected by bolts or rivets. The outer gas catalyst infrared catalytic plates 3 can be disassembled separately. The connection length of the gas catalyst infrared catalytic plates 3 modules can be adjusted according to the length of the production line. The hot air circulation system 4 includes a fan 401, an air duct 402, and a bellows nozzle 403. The bellows nozzle 403 is connected to the air duct 402. One end of the air duct 402 is connected to the bellows nozzle 403, and the other end is connected to the fan 401. The bellows nozzle 403 is arranged on both sides of the gas catalyst infrared catalytic plate, about 5 to 10 cm away from the gas catalyst infrared catalytic plate, and 5 to 10 cm away from the inner wall of the side of the furnace body. The hot air circulation insulation mainly utilizes the radiant heat generated during the infrared radiation heating process. The radiant heat emitted by the infrared catalytic plate 3 of the gas catalyst is extracted by the fan 401, and the radiant heat is input and output through the air duct 402 in a cycle. The hot air flow output by the bellows nozzle 403 is then controlled by a valve to control the circulation of the hot air flow in the furnace body 1, so that the conveying channel 101 of the furnace body 1 is heated and insulated. The angle and gap size of the bellows nozzle 403 can be adjusted to control the size and direction of the air flow. The bellows nozzle 403 is arranged on the periphery of the infrared catalytic plate 3 of the gas catalyst, so that the radiant heat emitted by the infrared catalytic plate 3 of the gas catalyst in the furnace body 1 is circulated and dispersed by adjusting the angle of the bellows nozzle 403 to the infrared catalytic plate 3 of the gas catalyst, thereby stabilizing the temperature in the furnace body 1, making the temperature distribution in the furnace body 1 more uniform, and making the surface of the pre-coated metal coil 7 heated more uniformly and dispersed. This process can effectively save energy and improve process stability.

[0023] like Figure 2As shown, the gas catalyst infrared catalytic plate 3 is a rectangular structure, with a length generally of about 50-150 cm, a width generally of about 45-65 cm, and a thickness of about 30 cm. A metal panel is installed on the back, and the metal panel is installed with a solenoid valve 301, a pressure reducing valve 302 and a thermocouple 303. The pressure reducing valve 302 can adjust the gas flow rate on the gas catalyst infrared catalytic plate, and the solenoid valve 301 can stabilize the high and low pressure cross-operation output, control the energy transmission size of the gas catalyst infrared catalytic plate 3, and then control the radiation energy and furnace temperature of the gas catalyst infrared catalytic plate 3. A metal mesh cover 304 is installed on the front to prevent damage to the gas catalyst infrared catalytic plate 3 due to external collision or falling objects. The gas catalyst infrared catalytic plates 3 are symmetrically installed on the inner walls of the upper and lower sides of the furnace body 1. A row of bellows nozzles 403 are arranged outside the gas catalyst infrared catalytic plates 3 for circulating the hot air flow in the furnace body 1 to maintain the temperature of the furnace body stable. The gas catalyst infrared catalytic plates 3 are connected side by side and arranged to be laid flat on the upper and lower walls of the furnace body 1. When the gas catalyst infrared catalytic plates 3 are laid flat in a row horizontally, the gas catalyst infrared catalytic plates 3 are provided with E, F, G and H, I, J ports. The gas catalyst infrared catalytic plates 3 are fixed and laid flat by bolts and riveting through the horizontal E, F, G and H, I, J ports. The gas catalyst infrared catalytic plates 3 at the outermost sides of the inlet and outlet of the furnace body 1 are only provided with E, F, G or H, I, J ports. When the gas catalyst infrared catalytic plates 3 are laid flat in two rows vertically, the gas catalyst infrared catalytic plates 3 are provided with A, B , C, D, E, F, G or A, B, C, D, H, I, J ports, the gas catalyst infrared catalytic plates 3 are fixed and laid flat by bolts and riveting through the vertical A, B, C, D and the horizontal E, F, G or H, I, J ports, the gas catalyst infrared catalytic plates 3 at the outermost sides of the inlet and outlet of the furnace body 1 are only provided with A, B, E, F, G and A, B, H, I, J ports or C, D, E, F, G and C, D, E, F, G, the laying direction is parallel to the conveying direction of the pre-coated metal coil 7, the pre-coated metal coil 7 is conveyed in the conveying channel 101 in the furnace body 1 in the air, the gas catalyst infrared catalytic plates 3 at the outermost sides of the inlet and outlet of the furnace body 1 are only provided and are between the areas surrounded by the installation of the gas catalyst infrared catalytic plates 3, which can maximize the guarantee that the upper and lower surfaces of the pre-coated metal coil 7 absorb infrared rays for radiation heating.

[0024] Furthermore, the infrared radiation heating is controlled by gas pulses, and the surface coating of the pre-coated metal coil 7 absorbs infrared rays and is heated to achieve the purpose of curing. When the temperature of the furnace body 1 reaches the target temperature value after continuous heating, the gas valve is closed, and the fan 401 is turned on to extract the heat released by the infrared catalytic plate 3 of the gas catalyst that continues to react, and the air flow inside the furnace body 1 is circulated through the air duct 402 and the bellows nozzle 403 to maintain the internal temperature of the furnace body 1 Stable and the average distribution of regional temperature, while the bellows nozzle 403 is arranged in parallel at the width edge of the pre-coated metal coil 7, which can effectively prevent foreign impurities or dust from being deposited on the surface of the pre-coated metal coil 7, and can also prevent the problem of powder accumulation on the edge of the pre-coated metal coil 7, thereby ensuring the cleanliness of the furnace body 1 and the flatness of the cured coating on the surface of the pre-coated metal coil 7.

[0025] In summary, in combination with the accompanying drawings, the pre-coated metal coil 7 is transported to the conveying channel 101 of the furnace body 1, and the gas undergoes a catalytic oxidation reaction through the gas catalyst infrared catalytic plate 3 in the furnace body 1, and the natural gas or propane gas is converted into medium- and long-wave infrared radiation through a special platinum catalyst, forming a radiation surface temperature of 175-480°C. The infrared rays can transfer energy and heat the surface coating of the pre-coated metal coil 7, and the surface coating of the pre-coated metal coil 7 begins to solidify. When the temperature in the furnace body 1 is heated to a certain temperature by radiation, the fan 401 of the hot air circulation system 4 is started, and the fan 401 extracts the hot air from the conveying channel 101 of the furnace body 1, circulates through the air duct 402, and continuously inputs the hot air into the conveying channel 101 in the furnace 1 through the bellows nozzle 403, to The furnace body 1 is kept warm and heated. At this time, the gas valve opening is controlled through pulse gas control to reduce unnecessary energy waste, save energy and reduce energy consumption. The bellows nozzle 403 is arranged on the periphery of the gas catalyst infrared catalytic plate 3, and the hot air in the furnace body 1 is circulated. The temperature distribution in the furnace body 1 tends to be stable and uniform. By adjusting the direction angle and size of the bellows nozzle 403, the effective area of ​​the gas catalyst infrared catalytic plate 3 and the effective area of ​​the surface of the pre-coated metal coil 7 can be effectively adjusted so that the heat emitted by the gas catalyst infrared catalytic plate 3 is evenly dispersed on the surface of the pre-coated metal coil 7, so that the surface of the pre-coated metal coil 7 is evenly heated, and the pre-coated metal coil 7 with high flatness is obtained, while the cleanliness of the furnace body 1 is ensured.

[0026] Compared with the prior art, the curing furnace for pre-coated metal coil powder color coating provided by the utility model adopts a combination of infrared radiation heating and hot air circulation system insulation, and there is no need to separately set up infrared radiation heating and hot air circulation heating furnace body 1, so the equipment occupies a small area, infrared radiation heating does not require ignition, and the gas catalyst catalytic plate 3 performs a flameless chemical oxidation reaction in the process of generating infrared rays, which requires less energy and does not produce toxic substances. The infrared heating generated by the gas catalyst infrared catalytic plate 3 is controlled by pulses, and its temperature rises rapidly. Combined with the insulation of the hot air circulation system 4, gas energy can be saved. Moreover, the infrared radiation wavelength generated by the gas catalyst infrared catalytic plate 4 is completely matched with the absorption spectrum of the powder coating and water, and only the carboxyl and hydroxyl molecules in the coating are heated. There is no obvious heating effect on the uncoated metal and air. All energy is concentrated and directly transferred to the coating, and the coating is cured from the inside out. It is safer, more efficient, energy-saving and environmentally friendly, and the temperature control is accurate. The temperature distribution in the furnace is uniform, so that the curing of the surface coating of the coil is more level and uniform, and it can be well applied to the curing of the surface coating of a large area of ​​plate.

[0027] The above-mentioned curing furnace for powder color coating of pre-coated metal coils is only an illustrative embodiment of the utility model and is not intended to limit the scope of the utility model. Any equivalent changes and modifications made by ordinary technicians in this field without departing from the concept and principle of the utility model should fall within the scope of protection of the utility model.

Claims

1. An environmentally friendly and efficient curing furnace for pre-coated metal coil powder color coating, characterized in that The curing furnace for powder color coating of pre-coated metal coils includes: a furnace body, an outer insulation layer, a gas catalyst infrared catalytic plate, and a hot air circulation system. The furnace body is provided with an inlet and an outlet. A sag meter is provided at the inlet of the furnace body, and an infrared thermometer is provided at the outlet. A conveying channel is provided inside, and an outer insulation layer is provided outside. The outer insulation layer is an aluminum silicate ceramic insulation layer. Gas catalyst infrared catalytic plates are symmetrically installed on the upper and lower sides of the conveying channel inside the furnace body. The gas catalyst infrared catalytic plates are connected side by side with each other, and the hot air circulation system includes a fan, an air duct, and a bellows nozzle.

2. The curing furnace for powder color coating of pre-coated metal coil according to claim 1, characterized in that: The distance between the furnace body conveying channel and the gas catalyst infrared catalytic plates on the upper and lower sides of the furnace body is greater than 10 cm, and the length of the conveying channel is consistent with the length of the furnace body.

3. The curing furnace for powder color coating of pre-coated metal coil according to claim 1, characterized in that: The furnace body is a straight-through structure, and the conveying channel is provided with a gas catalyst infrared catalytic plate and a hot air circulation system to provide infrared radiation heating and hot air circulation insulation respectively. The length of the furnace body is set according to the length and speed of the production line.

4. The curing furnace for powder color coating of pre-coated metal coil according to claim 1, characterized in that: The bellows nozzle is connected to the air duct, one end of the air duct is connected to the bellows nozzle, and the other end is connected to the fan. The bellows nozzle is arranged on both sides of the infrared catalytic plate of the gas catalyst.

5. The curing furnace for powder color coating of pre-coated metal coil according to claim 3, characterized in that: The infrared radiation heating mainly adopts a modular design. Each module adopts a symmetrical design and is composed of independent gas catalyst infrared catalytic plates. The gas catalyst infrared catalytic plates are connected by bolts or rivets. The outer gas catalyst infrared catalytic plates can be disassembled separately. The connection length of the gas catalyst infrared catalytic plate module can be adjusted according to the length of the production line.

6. The curing furnace for powder color coating of pre-coated metal coil according to claim 3, characterized in that: The infrared radiation heating adopts gas pulse control. The gas catalyst infrared catalytic plate is provided with a solenoid valve and a pressure reducing valve, which can adjust the gas flow rate on the gas catalyst infrared catalytic plate to control the energy transmission size, and then control the radiation energy of the gas catalyst infrared catalytic plate and the furnace body temperature.

7. The curing furnace for powder color coating of pre-coated metal coil according to claim 5, characterized in that: The gas catalyst infrared catalytic plate is in a rectangular structure, a metal panel is installed on the back, a solenoid valve, a pressure reducing valve and a thermocouple are installed on the metal panel, and a metal mesh cover is installed on the front.

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