Enamel spraying and firing device and method for stainless steel thin-walled water meter shell

Abstract

The invention relates to the technical field of stainless steel thin-wall enamel spraying and firing, and discloses a stainless steel thin-wall part water meter shell enamel spraying and firing device and method.The stainless steel thin-wall part water meter shell enamel spraying and firing method comprises the following steps that S1, electrostatic adsorption preparation is conducted firstly, S2, electrostatic adsorption powder hanging parts pass through a spraying gun in a dry powder room at a constant speed, and the spraying speed is increased; s3, the suspended water meter subjected to low-temperature area preheating electrostatic adsorption stably passes through a first air curtain, S4, the middle-temperature area preheating water meter is conveyed into a middle-temperature area isolated by a second air curtain at a constant speed from the low-temperature area, and S5, the preheated water meter passes through a third air curtain and then enters a high-temperature sintering area. According to the stainless steel water meter manufactured through the spraying technology, the problems that a paint protective layer on the surface is prone to falling off, the service life is affected by scale appearing on the surface, and a coating falls off in a large area are solved, and meanwhile the defect of leakage of some finished products can be overcome; the invention has the effects of attractive appearance, smoothness, corrosion prevention, leakage prevention and prolonged service life.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel thin-wall enamel spraying and firing, and in particular to a stainless steel thin-wall water meter shell enamel spraying and firing device and method. Background Art

[0002] The enamel spraying and firing device for stainless steel thin-walled water meter shell plays a very important role in the production process, especially in improving the corrosion resistance of the water meter shell, extending the service life, and improving the appearance. The purpose of using this device is to ensure that the enamel coating can be evenly and firmly attached to the surface of the water meter shell, while ensuring that the quality and performance of the coating meet the standard requirements.

[0003] The enamel spraying and firing device for stainless steel thin-walled water meter shell is mainly used to apply a layer of enamel coating on the surface of the water meter shell to improve the corrosion resistance, wear resistance and oxidation resistance of the water meter shell, thereby extending its service life and improving its appearance. This process generally includes several key steps such as spraying, drying, and firing, and the equipment and technology involved are also relatively complex.

[0004] At present, most of the products on the market are sprayed with paint or plastic spray powder. Paint is easily corroded and rubbed off, which makes the surface easy to fall off. Due to the special properties of the stainless steel surface itself, the color surface after spraying is easily scratched, which easily causes the color to fall off. The surface after plastic spraying is prone to scale in a humid environment, affecting the service life. The spraying effect is difficult to be even. The stainless steel surface has uneven texture, and the coating is not easy to spray evenly, resulting in the effect after spraying being not as expected. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a device and method for spraying and firing enamel on a stainless steel thin-wall water meter shell, which solves the special properties of the stainless steel surface itself. The colored surface after spraying is easily scratched, which easily causes the color to fall off. The surface after spraying is prone to scale in a humid environment, which affects the service life. The stainless steel surface has uneven texture, and the coating is not easy to spray evenly, resulting in the effect after spraying being not as expected.

[0006] To achieve the above purpose, the present invention is implemented by the following technical scheme: a method for spraying and firing enamel on a stainless steel thin-walled water meter shell, comprising the following steps:

[0007] S1. Prepare for electrostatic adsorption. Fix the water meter shell to be sprayed with water through a hook, then hang the hook on the hanging conveyor chain, transport it to the dry powder room, and start the high-voltage generator to form a negatively charged electrostatic field.

[0008] S2. The electrostatically adsorbed powder hanger passes through the spray gun at a uniform speed in the dry powder room. Under the action of the electrostatic field, the positively charged powder is quickly and evenly adsorbed to the various surfaces of the workpiece, so that the surface of the workpiece is covered with powder, completing the spraying work;

[0009] S3. Preheating in low temperature zone After electrostatic adsorption, the suspended water meter passes smoothly through the first air curtain and enters the low temperature zone, where the water meter is preheated initially through heat transfer;

[0010] S4, the water meter in the medium temperature zone is uniformly transported from the low temperature zone into the medium temperature zone isolated by the second air curtain. The water meter further absorbs heat, making its temperature gradually approach the conditions required for subsequent high temperature sintering, so that the water meter is fully preheated;

[0011] S5, the preheated water meter then passes through the third air curtain and enters the high-temperature sintering area for high-temperature sintering;

[0012] S6. After the high-temperature sintering, the water meter shell leaves the high-temperature zone and enters the medium-temperature zone for heat exchange and preliminary cooling.

[0013] S7, the water meter shell continues to move forward to the low temperature zone for heat exchange, further deep cooling, so that its temperature continues to decrease;

[0014] S8. After the finished product is fully cooled, the temperature of the water meter shell drops to a safe range, and then it smoothly reaches the finished product offline area through the conveyor line. The staff conducts the final quality inspection and appearance inspection on the water meter shell.

[0015] Preferably, in S1, the speed of the conveying suspension conveyor chain is 0.1-1 m / s, the output voltage of the high-voltage generating device is between 50-100 kV, the electric field strength of the electrostatic field is in the range of 10^5-10^7 V / m, and the current of the electrostatic field is 5-15 μA.

[0016] Preferably, in S2, the wind speed in the dry powder room is 0.5-2 m / s, the spray pressure of the spray gun is 0.2-0.6 MPa, the speed of the hanger passing through the spray gun is 0.2-0.5 m / s, the particle size of the powder is 10-100 microns, the voltage fluctuation range of the electrostatic field is ±5, and the distance between the spray gun and the workpiece is 150-300 mm.

[0017] Preferably, in S3, the wind speed of the first wind curtain is 5-10 m / s, the temperature of the low temperature zone is 150-200°C, the time for the water meter to pass through the first wind curtain is 10-20 seconds, the length of the low temperature zone is 3-4 meters, and the heat transfer coefficient is 10-50 W / m²・K.

[0018] Preferably, in S4, the heating power of the medium temperature zone is 10-20 kilowatts, the thermal radiation coefficient of the medium temperature zone is 0.8-0.9, the air circulation speed of the medium temperature zone is 3-5 meters per second, the initial temperature of the water meter entering the medium temperature zone is 200-250°C, the temperature uniformity of the medium temperature zone is within ±10°C, the surface temperature of the heating element in the medium temperature zone is 500-700°C, the temperature gradient between the medium temperature zone and the low temperature zone is 50-100°C / meter, and the heating rate of the water meter in the medium temperature zone is 20-30°C / minute.

[0019] Preferably, in S5, the wind speed of the third air curtain is 10-15 m / s, the temperature of the high-temperature sintering zone is 700-900°C, the heating methods of the high-temperature sintering zone include electric heating and gas heating, the residence time of the water meter in the high-temperature sintering zone is 10 minutes, the temperature difference of the temperature uniformity of the high-temperature sintering zone is controlled within ±5°C, the micro-positive pressure of the furnace pressure in the high-temperature sintering zone is 10-50Pa, the thermal radiation intensity of the high-temperature sintering zone is 5×10^4-1×10^5W / m², the temperature gradient between the high-temperature sintering zone and the medium-temperature zone is 100-200°C / m, and the high-temperature sintering zone adopts a U-shaped symmetric overall length of 10 meters.

[0020] Preferably, in S6, the temperature of the medium temperature zone for preliminary cooling is 400-500°C, the residence time of the water meter shell in the medium temperature zone for preliminary cooling is 2-4 minutes, the cooling medium in the medium temperature zone includes air, the flow rate of the cooling medium is 8-12 m / s, the heat exchange coefficient is 30-80W / m²・K, and the temperature gradient between the medium temperature zone and the high temperature zone is 150-250°C / m.

[0021] Preferably, in S7, the temperature of the low temperature zone for deep cooling is 100-200°C, the residence time of the water meter shell in the low temperature zone for deep cooling is 3-5 minutes, the cooling medium in the low temperature zone includes air, the flow rate of the cooling medium is 5-10 m / s, the heat exchange coefficient is 20-50W / m²・K, and the temperature gradient between the low temperature zone and the medium temperature zone is 100-150°C / m.

[0022] Preferably, in S8, the temperature in the safety range is lower than 50°C, the speed of the conveyor line is 0.2-0.5 m / s, the standards and indicators of the quality inspection include a coating thickness tolerance of ±0.05 mm, a surface roughness Ra value of less than 1.6 μm, and the light intensity of the appearance inspection is 800-1200 lux.

[0023] A stainless steel thin-walled water meter shell enamel spraying and firing device, comprising a water meter upper line, the water meter upper line is connected to a hanging conveyor chain, the water meter upper line is connected to a dry powder room through the hanging conveyor chain, the dry powder room is connected to a first group of air curtains through the hanging conveyor chain, a second group of air curtains is arranged at the rear side of the first group of air curtains, a low temperature zone is arranged in the middle of the first group of air curtains and the second group of air curtains, the length of the low temperature zone is 4 meters, the first group of air curtains and the second group of air curtains are each arranged on the left and right sides of the low temperature zone, and the middle part is separated by a wall, and a third group of air curtains is arranged at the rear side of the second group of air curtains The wind curtain, a medium temperature zone is arranged in the middle of the second and third wind curtains, the length of the medium temperature zone is 4 meters, a high temperature sintering zone is arranged on the rear side of the third wind curtain, the high temperature sintering zone is U-shaped, and the U-shaped symmetrical length of the high temperature sintering zone is 10 meters, and one group of the third wind curtains is arranged on each side and distributed on the left and right sides of the high temperature sintering zone, the hanging conveyor chain is coiled inside the high temperature sintering zone and enters from the left side of the U shape and exits from the right side, the hanging conveyor chain is connected to a uniform speed conveyor chain, the uniform speed conveyor chain is connected to a cooling down line, and the cooling down line is connected to the water meter upper line.

[0024] The present invention provides a device and method for spraying and firing enamel on a stainless steel thin-wall water meter shell. It has the following beneficial effects:

[0025] 1. The overall surface and built-in surface of the stainless steel water meter made by the spraying process of the present invention are extremely smooth and beautiful. At the same time, the problems of easy peeling of the surface paint protective layer, scale on the surface affecting the service life and large-scale peeling of the coating are solved. At the same time, it can also make up for the defects of leakage of some finished parts, because the enamel spraying and firing can further fill the leakage gaps through hot melting, thereby achieving sealing and leakage prevention. The stainless steel thin-walled water meter produced by this spraying process has the effects of being beautiful and smooth, anti-corrosion, leak-proof and extending the service life.

[0026] 2. The overall production effect of the present invention is high, batch spraying is done at one time, the production efficiency is high, and it is relatively energy-saving. The enamel fills the gaps on the surface of the water meter shell, and can also solve the leakage problem of some stainless steel water meters. It can withstand greater water pressure test pressure and has a longer service life. The integrated optimized design also greatly reduces labor costs. It also solves the problem of easy detachment and unevenness of spray paint on the market.

[0027] 3. The high-temperature sintering zone of the present invention is U-shaped and 10 meters long. It takes about 10 minutes to transport it into the high-temperature zone. That is, after the water meter shell is fired for 10 minutes, the enamel hot-melt effect can reach the best state and integrate with the stainless steel to achieve the effect of surface attachment and filling. This optimal design can reduce the energy consumption of high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1This is a method flow chart of a method for spraying and firing enamel on a stainless steel thin-wall water meter shell according to the present invention;

[0029] Figure 2 It is a partial schematic diagram of the high-temperature sintering zone of a stainless steel thin-wall water meter shell enamel spraying and firing device of the present invention.

[0030] Among them, 1. Water meter online; 2. Suspension conveyor chain; 3. Dry powder room; 4. The first set of air curtains; 5. Low temperature zone; 6. The second set of air curtains; 7. Medium temperature zone; 8. The third set of air curtains; 9. High temperature sintering zone; 10. Uniform speed conveyor chain; 11. Cooling offline. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example:

[0033] Please see attached Figure 1 The embodiment of the present invention provides a method for spraying enamel on a stainless steel thin-wall water meter shell, comprising the following steps:

[0034] S1, first prepare for electrostatic adsorption, first fix the water meter shell to be sprayed with water through the hook, then hang the hook on the hanging conveyor chain 2, transport it to the dry powder room 3, and start the high-voltage generator to form a negatively charged electrostatic field;

[0035] S2, electrostatic adsorption powder hanger passes through the spray gun at a uniform speed in the dry powder room 3. Under the action of the electrostatic field, the positively charged powder is quickly and evenly adsorbed to each surface of the workpiece, so that the surface of the workpiece is covered with powder, and the spraying work is completed;

[0036] S3, preheating of low temperature zone 5 The suspended water meter after electrostatic adsorption passes smoothly through the first air curtain and enters the low temperature zone 5, where the water meter is preliminarily preheated by heat transfer;

[0037] S4, the water meter preheated in the medium temperature zone 7 is uniformly transported from the low temperature zone 5 into the medium temperature zone 7 isolated by the second air curtain, and the water meter further absorbs heat, so that its temperature gradually approaches the conditions required for subsequent high temperature sintering, so that the water meter is fully preheated;

[0038] S5, the preheated water meter then passes through the third air curtain and enters the high temperature sintering zone 9 for high temperature sintering;

[0039] S6, when the water meter shell leaves the high temperature zone after high temperature sintering, it enters the medium temperature zone 7 for heat exchange and preliminary cooling;

[0040] S7, the water meter shell continues to move forward to the low temperature zone 5 for heat exchange, and further deep cooling, so that its temperature continues to decrease;

[0041] S8. After the finished product is fully cooled, the temperature of the water meter shell drops to a safe range, and then it smoothly reaches the finished product offline area through the conveyor line. The staff conducts the final quality inspection and appearance inspection on the water meter shell.

[0042] In S1, the speed of the conveying suspension conveyor chain 2 is 0.1-1 m / s, the output voltage of the high voltage generating device is between 50-100 kV, the electric field strength of the electrostatic field is in the range of 10^5-10^7 V / m, and the current of the electrostatic field is 5-15 μA.

[0043] Specifically, regarding the conveying suspension conveyor chain 2, this speed range can ensure that materials or products are transported smoothly and orderly, and can be accurately transported from one production link to the next link according to the established process, effectively avoiding the displacement and collision damage of objects caused by too fast speed, as well as low production efficiency and disconnection of process connections caused by too slow speed. The stable conveying speed maintains the efficient and continuous operation of the production line, avoids the situation where materials stagnate and wait, and thus helps to increase the output of products per unit time. In terms of product quality assurance, it can ensure that the objects remain intact during transportation and arrive at the corresponding processing position accurately, so that the quality of the final product can be steadily improved;

[0044] As the key energy source of the electrostatic field, the high-voltage generator causes the electrode to accumulate a large amount of charge, thereby creating an electrostatic field environment of appropriate intensity. It plays a key role in application scenarios such as electrostatic spraying and electrostatic dust removal. Such high-voltage output can create a strong electrostatic field that is sufficient to overcome many external interferences. For example, in large-scale electrostatic dust removal equipment, it can efficiently absorb dust particles, significantly improve dust removal efficiency, and make the exhaust air cleaner.

[0045] The electrostatic field has a high electric field strength of 10^5-10^7 V / m, which can exert a considerable electric field force on the charged particles or polarizable objects in it, meeting the needs of particle acceleration in electrostatic accelerators and high-precision processing of workpieces during electron beam processing;

[0046] A current of 5-15 microamperes can keep the electrostatic field in a relatively stable and safe state, while ensuring its effect on objects is sustained. For example, in electrostatic preservation, it can regulate the surface charge and cell activity of agricultural products and extend the shelf life.

[0047] The wind speed in S2 and dry powder room 3 is 0.5-2 m / s, the spray pressure of the spray gun is 0.2-0.6 MPa, the speed of the hanger passing through the spray gun is 0.2-0.5 m / s, the particle size of the powder is 10-100 microns, the voltage fluctuation range of the electrostatic field is ±5, and the distance between the spray gun and the workpiece is 150-300 mm.

[0048] Specifically, the wind speed in the dry powder room 3 maintains air flow, takes away excess powder, and ensures uniform distribution of powder. This improves operation safety and makes the powder coating on the surface of the pendant more uniform;

[0049] The spray pressure of the spray gun provides power for the powder, which is convenient for adjusting the adhesion effect as needed. It has the effect of improving the efficiency of powder utilization and ensuring the quality of spraying;

[0050] The speed at which the parts pass through the spray gun determines how long they stay, and other parameters determine the spraying effect. Improve the uniformity and integrity of the coating, and balance production efficiency and quality;

[0051] The different particle sizes of powders affect the performance of the powders at each stage and can be selected as needed. Create coatings with different appearances and enhance the protective performance of the coatings;

[0052] The voltage fluctuation range of the electrostatic field ensures the stability of the electrostatic field, guarantees the accuracy of powder adsorption and spraying, improves the uniformity of spraying, and facilitates stable and efficient operation;

[0053] The distance between the spray gun and the workpiece affects the effect of powder spraying onto the workpiece, so it is easy to adjust flexibly to ensure coating quality and improve work efficiency.

[0054] In S3, the wind speed of the first wind curtain is 5-10 m / s, the temperature of low temperature zone 5 is 150-200℃, the time for the water meter to pass through the first wind curtain is 10-20 seconds, the length of low temperature zone 5 is 3-4 meters, and the heat transfer coefficient is 10-50W / m²・K.

[0055] Specifically, the wind speed of the first air curtain forms an airflow barrier at an appropriate speed, blocking the exchange of heat and impurities inside and outside, and maintaining the stability of the environment in the relevant area. This is conducive to creating a good working environment, reducing heat loss and external interference, and ensuring the smooth progress of subsequent processes;

[0056] The temperature in low temperature zone 5 provides a specific low temperature environment, which helps the water meter achieve a certain degree of temperature control and performance stability at this stage. It can reasonably reduce the temperature of the water meter, reduce the impact of thermal stress, ensure that the structure and performance meet the requirements, and improve product quality;

[0057] The time it takes for the water meter to pass through the first wind curtain determines how long the water meter is affected by the wind curtain, and together with the wind speed, affects the protection and heat exchange. Ensure that the wind curtain effectively protects or regulates the temperature of the water meter, and ensure the connection between processes and product status;

[0058] The length of the low temperature zone 5 provides a suitable space range, so that the water meter has enough distance in the low temperature zone 5 to complete the corresponding temperature change process. It ensures that the water meter can fully adapt to the low temperature environment and achieve the expected cooling effect, which is conducive to the subsequent production process.

[0059] The heat transfer coefficient reflects the strength of heat transfer capacity and affects the efficiency and degree of heat exchange between the low temperature zone 5 and the water meter. It helps to reasonably control the cooling speed of the water meter, make the temperature change more in line with the production process requirements, and improve production efficiency.

[0060] The heating power of S4 and medium temperature zone 7 is 10-20 kilowatts, the thermal radiation coefficient of medium temperature zone 7 is 0.8-0.9, the air circulation speed of medium temperature zone 7 is 3-5 meters per second, the initial temperature of the water meter entering the medium temperature zone 7 is 200-250°C, the temperature uniformity of the medium temperature zone 7 is within ±10°C, the surface temperature of the heating element of the medium temperature zone 7 is 500-700°C, the temperature gradient between the medium temperature zone 7 and the low temperature zone 5 is 50-100°C / meter, and the heating rate of the water meter in the medium temperature zone 7 is 20-30°C / minute.

[0061] Specifically, the heating power of the medium temperature zone 7 ensures that the temperature in the medium temperature zone 7 can be stably maintained in an appropriate range, which is conducive to the stable heating of the water meter and reduces abnormal temperature fluctuations caused by insufficient or excessive power. On the other hand, it also helps to improve the overall production efficiency, so that operations such as water meter heating can be carried out in an orderly manner as planned, ensuring stable and reliable product quality;

[0062] The high thermal radiation coefficient of the medium temperature zone 7 means that the medium temperature zone 7 can efficiently transfer heat through thermal radiation, allowing the heat to be quickly and evenly distributed throughout the area, so that all parts of the water surface in it can fully receive heat, which plays a key role in improving heating uniformity. Not only can the water surface be heated more evenly, avoiding local overheating or insufficient heating, thereby improving the consistency of product heating and ensuring the quality of subsequent processing, but it also helps to reduce heat loss and waste, improve energy utilization, reduce production costs, and achieve an efficient and energy-saving heating process;

[0063] The air circulation speed of the medium temperature zone 7 not only ensures a more uniform temperature distribution in the entire medium temperature zone 7, so that the water meter can be in a similar thermal environment at all positions, improving the heating quality, but also speeds up the heat exchange speed, making the water meter heating process more stable and efficient, which helps to improve the production rhythm and shorten the heating time of a single product;

[0064] The initial temperature of the water meter when it enters the medium temperature zone 7 helps to reduce adverse effects such as thermal shock that may be caused by excessive initial temperature differences, improve the structural stability of the water meter during the heating process, and also facilitate accurate control of the final temperature, ensuring stable product performance and meeting the strict requirements for water meter temperature characteristics in different usage scenarios.

[0065] The temperature uniformity of the medium temperature zone 7 is controlled within such a narrow range, which can ensure that the water meters at various positions in the medium temperature zone 7 are basically heated in the same manner, avoiding the stress concentration caused by the different degrees of thermal expansion and contraction of various parts of the water meter due to temperature differences, and ensuring the consistency of product heating quality. The water meter can be heated evenly during the entire heating process, effectively improving the overall performance of the product, reducing the defective rate caused by uneven temperature, and increasing the production qualification rate. At the same time, it also provides a stable temperature basis for subsequent operations such as connection with other temperature zones, which is conducive to the smooth development of the entire production process;

[0066] The surface temperature of the heating element in the medium temperature zone 7 The surface temperature of the heating element in this temperature range can provide sufficient high-temperature heat source for the medium temperature zone 7, transfer heat to the surrounding environment and the water meter through various methods such as heat conduction and heat radiation, and can adjust the temperature according to actual needs to adapt to the changes in heat demand at different stages. It can not only ensure that there is enough heat in the medium temperature zone 7 to achieve stable temperature rise of the water meter and meet the temperature requirements of the production process, but also avoid the risk of failure caused by too high or too low temperature of the heating element, extend the service life of the heating element, reduce equipment maintenance costs, and ensure long-term reliable operation of the heating system;

[0067] The temperature gradient between the medium temperature zone 7 and the low temperature zone 5 is reasonable. The temperature gradient can make the water meter have a relatively stable temperature change process that conforms to the laws of physics when it transitions from the low temperature zone 5 to the medium temperature zone 7, avoiding the adverse effects of sudden temperature changes on the structure and performance of the water meter, and ensuring that the product can be heated normally at the junction of different temperature zones. It not only helps to improve the stability of the water meter during the temperature zone conversion process and reduce the risk of damage caused by rapid temperature changes, but also makes the temperature control on the entire production line more scientific and reasonable, optimizes the heating process, and improves production efficiency and the overall quality level of the product.

[0068] The heating rate of the water meter in the medium temperature zone 7 is such a heating rate range that the water meter can gradually heat up in the medium temperature zone 7 according to the set rhythm, and cooperate with the parameters such as heating power and temperature uniformity to ensure that the water meter is heated evenly and can accurately reach the target temperature. At the same time, it is also convenient to flexibly adjust the heating rate according to different product requirements. On the one hand, it ensures the stability of the water meter heating process and reduces the quality problems that may be caused by heating too fast or too slow. On the other hand, it helps to reasonably arrange production time, improve production efficiency, and achieve more qualified products per unit time under the premise of ensuring product quality.

[0069] The wind speed of the middle and third air curtains of S5 is 10-15 m / s, the temperature of the high-temperature sintering zone 9 is 700-900℃, the heating methods of the high-temperature sintering zone 9 include electric heating and gas heating, the residence time of the water meter in the high-temperature sintering zone 9 is 10 minutes, the temperature difference of the temperature uniformity of the high-temperature sintering zone 9 is controlled within ±5℃, the micro-positive pressure of the furnace pressure of the high-temperature sintering zone 9 is 10-50Pa, the thermal radiation intensity of the high-temperature sintering zone 9 is 5×10^4-1×10^5W / m², the temperature gradient between the high-temperature sintering zone 9 and the medium temperature zone 7 is 100-200℃ / meter, and the high-temperature sintering zone 9 adopts a U-shaped symmetric overall length of 10 meters.

[0070] Specifically, the wind speed of the third air curtain within this wind speed range can form a strong airflow barrier, effectively blocking the mixing of external air and the diffusion of internal heat, dust, etc., which plays a key role in maintaining a relatively stable and independent thermal environment of the high-temperature sintering zone 9. At the same time, it can also assist in adjusting the direction of the internal airflow to ensure that the heat distribution of each area is more reasonable and orderly;

[0071] The temperature of high temperature sintering zone 9 is a key factor in meeting the sintering process requirements of water meters. Under the high temperature environment of 700-900℃, the substances inside the water meter can undergo a series of physical and chemical changes, such as optimization of crystal structure and better fusion of various components, which significantly improves the performance of the water meter. Moreover, this temperature range can be appropriately adjusted according to the specific material and specifications of the water meter to achieve the best sintering effect.

[0072] The heating method of the high-temperature sintering zone 9 can not only ensure sufficient and stable heat supply at different production stages and different output requirements, but also realize accurate temperature control, reduce temperature fluctuations, improve sintering quality, and take into account the control of production costs, thereby improving the economy and reliability of the entire production process, and enabling enterprises to have better cost and quality advantages in market competition;

[0073] The residence time of the water meter in the high-temperature sintering zone 9 can improve the performance of the water meter comprehensively and stably, such as making the structure more compact and the strength higher, effectively reducing the problems of incomplete sintering and uneven performance caused by insufficient residence time, improving the quality qualification rate of the product, and helping to reasonably arrange the production rhythm, improve production efficiency, and realize efficient and stable large-scale production;

[0074] The temperature uniformity of the high-temperature sintering zone 9 greatly improves the yield of the product, reduces defective products caused by uneven temperature, and makes the performance indicators of the water meter more uniform and stable. Whether it is hardness, density or other physical and chemical properties, they can reach high standards, meet the strict requirements of different users for water meter quality, and enhance the competitiveness of the product in the market;

[0075] The furnace pressure of the high-temperature sintering zone 9 can effectively protect the water meter from adverse factors such as oxidation during the high-temperature sintering process, improve the appearance quality and internal performance of the product, ensure the stability of the sintering effect, reduce temperature fluctuations and incomplete combustion caused by abnormal furnace pressure, improve energy utilization efficiency, extend equipment service life, and ensure the safe and stable operation of the entire production system;

[0076] The heat radiation intensity of the high-temperature sintering zone 9 helps to shorten the sintering time of the water meter and improve production efficiency. At the same time, it ensures that the water meter can be fully and evenly heated at high temperature, so that the sintering effect of the product is better and the performance is better. For example, the density and strength of the water meter are improved to meet higher quality standards, and energy consumption is reduced to a certain extent, achieving the production goal of high efficiency and energy saving;

[0077] The temperature gradient between the high temperature sintering zone 9 and the medium temperature zone 7 can not only reduce the risk of water meter damage caused by rapid temperature changes and improve the yield rate of the product, but also make the entire heating and sintering process more scientific and reasonable, optimize the production process, improve production efficiency, and at the same time ensure the final performance quality of the water meter, so that it can reach an ideal state in all aspects of performance indicators and meet high-quality production requirements;

[0078] The high-temperature sintering zone 9 adopts a U-shaped symmetry with an overall length of 10 meters, which can improve the heat utilization efficiency and reduce energy consumption. At the same time, it ensures the consistency of water meter sintering quality, improves the mass production capacity of products, meets the larger market demand, and makes the layout of the entire production system more reasonable and compact, reduces the equipment footprint, improves the space utilization of the production site, and reduces production costs.

[0079] The temperature of S6 and medium temperature zone 7 for preliminary cooling is 400-500℃, the residence time of the water meter shell in medium temperature zone 7 for preliminary cooling is 2-4 minutes, the cooling medium of medium temperature zone 7 includes air, the flow rate of the cooling medium is 8-12 m / s, the heat exchange coefficient is 30-80W / m²・K, and the temperature gradient between medium temperature zone 7 and high temperature zone is 150-250℃ / m.

[0080] Specifically, the temperature of the medium temperature zone 7 for preliminary cooling helps to maintain the structural integrity of the water meter in the preliminary cooling stage, reduce quality problems such as cracking and deformation caused by rapid temperature changes, pave the way for subsequent further cooling and other processes, and ensure that the physical and chemical properties of the water meter are stably maintained under reasonable temperature changes, ensure that the quality of the final product meets the requirements, and improve the yield rate of the product;

[0081] The residence time of the water meter shell in the medium temperature zone 7 for initial cooling can allow the water meter shell to reach a more appropriate initial cooling degree at this stage, avoiding insufficient cooling due to too short residence time or too long residence time affecting production efficiency, effectively reducing the temperature of the water meter shell, so that its internal thermal stress can be reasonably released, improving product quality stability, and helping to reasonably control the rhythm of the entire production process, ensuring smooth connection between various processes, and improving overall production efficiency;

[0082] The cooling medium in the medium temperature zone 7 can not only effectively reduce the temperature of the water meter shell and achieve the purpose of preliminary cooling, but also reduce production costs while ensuring the cooling effect, reduce adverse impacts on the environment, and meet the requirements of green production. In addition, the good air flow can make the temperature distribution in the entire medium temperature zone 7 relatively uniform, which helps to improve the consistency of water meter shell cooling and improve the uniformity of product quality;

[0083] The flow rate of the cooling medium speeds up the cooling of the water meter shell, shortens the time required for initial cooling, improves production efficiency, and ensures the uniformity of cooling of the water meter shell, reducing product quality problems caused by uneven cooling, such as local deformation and performance differences, making product quality more stable and reliable, meeting the requirements of high-quality production, and helping to optimize the entire cooling process and improve the stability of the production process;

[0084] The heat exchange coefficient can improve the cooling efficiency, making the initial cooling process of the water meter shell in the medium temperature zone 7 more efficient, allowing the water meter shell to reach the expected cooling temperature as soon as possible, thereby saving time for the subsequent cooling stage or other processes and improving the operating efficiency of the entire production line. In addition, a stable heat exchange coefficient range is conducive to ensuring the uniformity of cooling, ensuring the consistency of product quality, and reducing product defects caused by unstable heat exchange;

[0085] The temperature gradient between the medium temperature zone 7 and the high temperature zone helps to reduce the risk of quality problems such as cracking and deformation of the water meter case when it enters the medium temperature zone 7 from the high temperature, thereby improving the product yield rate and ensuring the smoothness of the temperature zone conversion in the entire production process, making the connection between each process closer and more reasonable, optimizing the entire production process, improving the overall production efficiency, and ensuring that the quality of the water meter case produced meets high standards.

[0086] The temperature of S7 medium and low temperature zone 5 for deep cooling is 100-200℃, the residence time of the water meter shell in the low temperature zone 5 for deep cooling is 3-5 minutes, the cooling medium of the low temperature zone 5 includes air, the flow rate of the cooling medium is 5-10 m / s, the heat exchange coefficient is 20-50W / m²・K, and the temperature gradient between the low temperature zone 5 and the medium temperature zone 7 is 100-150℃ / m.

[0087] Specifically, the temperature of the low temperature zone 5 for deep cooling helps to further improve the quality stability of the water meter shell, reduce the dimensional changes and performance fluctuations that may be caused by excessive temperature, and ensure that the water meter shell can maintain good performance during long-term use. At the same time, it also creates favorable conditions for the smooth implementation of subsequent processes, improves the consistency of the entire production process and the quality reliability of the final product, and effectively reduces the defective product rate;

[0088] The residence time of the water meter case in the deep cooling of the low temperature zone 5 allows the water meter case to reach an ideal low temperature state in the deep cooling stage, effectively reducing its temperature, so that the internal thermal stress can be more fully released, and the structural stability and performance consistency of the product can be improved, avoiding the situation where insufficient cooling or excessive residence time affects the production efficiency. At the same time, it helps to reasonably control the production rhythm, ensure the efficient connection between various processes, and improve the overall production efficiency;

[0089] The cooling medium in low temperature zone 5 can not only reliably reduce the temperature of the water meter shell and achieve the purpose of deep cooling, but also reduce production costs while ensuring the cooling effect, which is in line with the concept of green production. In addition, the good fluidity of air helps to make the temperature distribution in low temperature zone 5 more uniform, ensure the consistency of cooling degree of each part of the water meter shell, and improve the uniformity and stability of product quality;

[0090] The flow rate of the cooling medium accelerates the deep cooling speed of the water meter shell and shortens the residence time in the low temperature zone 5, which helps to improve the overall production efficiency and reduce the production cycle. It can also ensure the uniformity of cooling of the water meter shell and prevent product quality problems caused by uneven cooling, such as local deformation and performance differences, making the product quality more stable and reliable, meeting the requirements of high-quality production, and optimizing the entire deep cooling process;

[0091] The heat exchange coefficient helps to improve the efficiency of deep cooling, so that the water meter shell can reach the set low temperature zone 5 more quickly, improve production efficiency, and reduce the time spent in the deep cooling stage. In addition, a stable heat exchange coefficient range is conducive to ensuring the uniformity of cooling, avoiding inconsistent cooling levels in different parts of the water meter shell due to unstable heat exchange, thereby ensuring the consistency of product quality and reducing the defective rate of products;

[0092] The temperature gradient between the low temperature zone 5 and the medium temperature zone 7 helps to reduce the risk of cracking, deformation and other quality problems of the water meter shell during the temperature zone conversion, improve the product yield rate, and at the same time ensure the smoothness of the temperature zone conversion in the entire production process, making the connection between each process more closely and reasonably, optimizing the entire production process, improving the overall production efficiency, and ensuring that the quality of the produced water meter shell meets high standards;

[0093] S8 medium and safe range of temperature is below 50℃, the conveyor line speed is 0.2-0.5 m / s, the quality inspection standards and indicators include coating thickness tolerance of ±0.05 mm, surface roughness Ra value less than 1.6 microns, and the light intensity of appearance inspection is 800-1200 lux;

[0094] Specifically, from the perspective of personnel, the temperature within the safe range creates a safe working environment, reduces the possibility of safety accidents, and allows operators to safely carry out tasks such as quality inspection. From the perspective of products and equipment, it helps to maintain the original performance and quality of the product, extend the service life of the equipment, ensure the smooth progress of subsequent links in the entire production process, and improve the overall stability and reliability of the production system;

[0095] The speed of the conveyor line helps to improve the accuracy of quality inspection, ensuring that inspectors have sufficient time to conduct a comprehensive assessment of the product and promptly discover possible quality problems, thereby ensuring that product quality meets requirements. At the same time, on the basis of ensuring the quality of inspection, a certain production efficiency is maintained, so that products can flow between processes as planned, avoiding stagnation or delays in production links, and optimizing the continuity of the entire production process;

[0096] By strictly controlling these quality inspection indicators, we can screen out products that meet high quality requirements, improve the overall quality of products, and enhance the competitiveness of products in the market. Products that do not meet the standards can be discovered in time and reworked or adjusted to prevent defective products from entering the market, maintaining the reputation and brand image of the company's products. At the same time, it also helps companies optimize and improve production processes based on test feedback data, and improve the stability and controllability of the production process;

[0097] The light intensity of appearance inspection can effectively improve the accuracy and reliability of appearance inspection, ensure that the product appearance quality meets the requirements, and reduce customer complaints caused by appearance problems. At the same time, the appropriate light intensity makes it easier for inspectors to make quick and accurate judgments, improve the efficiency of appearance inspection, and thus improve the efficiency of the entire quality inspection process, ensuring that products can be produced and delivered on time and with high quality.

[0098] Please see attached Figure 2A stainless steel thin-walled water meter shell enamel spraying and firing device comprises a water meter upper line 1, the water meter upper line 1 is connected with a hanging conveyor chain 2, the water meter upper line 1 is connected with a dry powder room 3 through the hanging conveyor chain 2, the dry powder room 3 is connected with a first group of air curtains 4 through the hanging conveyor chain 2, the first group of air curtains 4 is provided with a second group of air curtains 6 at the rear side, a low temperature zone 5 is provided in the middle of the first group of air curtains 4 and the second group of air curtains 6, the length of the low temperature zone 5 is 4 meters, the first group of air curtains 4 and the second group of air curtains 6 are provided with a group of walls in the middle on the left and right sides of the low temperature zone 5, and the second group of air curtains 6 are provided with a third group of air curtains at the rear side. A medium temperature zone 7 is arranged in the middle of the wind curtain 8, the second group of wind curtains 6 and the third group of wind curtains 8, and the length of the medium temperature zone 7 is 4 meters. A high temperature sintering zone 9 is arranged on the rear side of the third group of wind curtains 8. The high temperature sintering zone 9 is U-shaped, and the U-shaped symmetrical length of the high temperature sintering zone 9 is 10 meters. The third group of wind curtains 8 are arranged on the left and right sides of the high temperature sintering zone 9. The hanging conveyor chain 2 is coiled inside the high temperature sintering zone 9 and enters from the left side of the U-shape and exits from the right side. The hanging conveyor chain 2 is connected to a uniform speed conveyor chain 10, and the uniform speed conveyor chain 10 is connected to a cooling down line 11, and the cooling down line 11 is connected to the water meter upper line 1.

[0099] Specifically, the material is first loaded through the water meter line 1 and then sent to the interior of the dry powder room 3 through the hanging conveyor chain 2. During use, the high voltage generation principle is adopted to form a negatively charged electrostatic field. When the hanger passes through the spray gun in the dry powder room 3, i.e., the spray room, the positively charged powder is adsorbed onto the workpiece. The hanging water meter after electrostatic adsorption then passes through the first group of wind curtains 4 to enter the low temperature zone 5 for preheating. The first group of wind curtains 4 also plays the role of the first dust isolation. Then it is transported to the medium temperature zone 7 isolated by the second group of wind curtains 6 for further preheating. The low temperature zone 5 and the medium temperature zone 7 are 4 meters long, so the dry powder room 3 passes through the low temperature zone 5 and the medium temperature zone 7 for about 3 minutes. If it is too long, it will cause rapid heat loss and high energy consumption. Then After passing through the third set of wind curtains 8, it enters the high-temperature sintering zone 9. The high-temperature sintering zone 9 adopts a U-shaped symmetrical overall length design of 10 meters. The length design of the high-temperature sintering zone 9 is calculated based on actual tests. It takes about 10 minutes to transport it into the high-temperature sintering zone 9, that is, after 10 minutes of firing, the enamel hot-melt effect can reach the best state and integrate with the stainless steel to achieve the effect of surface attachment and filling. This optimal design can reduce high-temperature energy consumption. If the high-temperature sintering zone 9 fails to achieve the effect, it will increase the consumption of heat energy if it is too long. After a period of time, it will initially enter the medium-temperature zone 7 and the low-temperature zone 5 for heat exchange for transition cooling, and finally pass through the conveyor line to the finished product offline area.

[0100] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for spraying enamel on a stainless steel thin-wall water meter shell, characterized in that: The following steps are involved: S1, first prepare for electrostatic adsorption, first fix the water meter shell to be sprayed with water through a hook, then hang the hook on the hanging conveyor chain (2), transport it to the dry powder room (3), and start the high-voltage generating device to form a negatively charged electrostatic field; S2, the electrostatically adsorbed powder hanger passes through the spray gun at a uniform speed in the dry powder room (3). Under the action of the electrostatic field, the positively charged powder is quickly and evenly adsorbed to the various surfaces of the workpiece, so that the surface of the workpiece is covered with powder, completing the spraying work; S3, preheating in low temperature zone (5) The suspended water meter after electrostatic adsorption passes smoothly through the first air curtain and enters the low temperature zone (5), where the water meter is preliminarily preheated by heat transfer; S4, the preheated water meter in the medium temperature zone (7) is uniformly transported from the low temperature zone (5) into the medium temperature zone (7) isolated by the second air curtain, where the water meter further absorbs heat, gradually bringing its temperature close to the conditions required for subsequent high temperature sintering, so that the water meter is fully preheated; S5, the preheated water meter then passes through the third air curtain and enters the high temperature sintering zone (9) for high temperature sintering; S6, when the water meter shell leaves the high temperature zone after high temperature sintering, it enters the medium temperature zone (7) for heat exchange and preliminary cooling; S7, the water meter shell continues to move forward to the low temperature zone (5) for heat exchange, and further deep cooling, so that its temperature continues to decrease; S8. After the finished product is fully cooled, the temperature of the water meter shell drops to a safe range, and then it smoothly reaches the finished product offline area through the conveyor line. The staff conducts the final quality inspection and appearance inspection on the water meter shell.

2. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S1, the speed of the conveying suspension conveyor chain (2) is 0.1-1 m / s, the output voltage of the high voltage generating device is between 50-100 kV, the electric field strength of the electrostatic field is in the range of 10^5-10^7 V / m, and the current of the electrostatic field is 5-15 μA.

3. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S2, the wind speed in the dry powder room (3) is 0.5-2 m / s, the spray pressure of the spray gun is 0.2-0.6 MPa, the speed of the hanger passing through the spray gun is 0.2-0.5 m / s, the particle size of the powder is 10-100 μm, the voltage fluctuation range of the electrostatic field is ±5, and the distance between the spray gun and the workpiece is 150-300 mm.

4. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S3, the wind speed of the first wind curtain is 5-10 m / s, the temperature of the low temperature zone (5) is 150-200°C, the time for the water meter to pass through the first wind curtain is 10-20 seconds, the length of the low temperature zone (5) is 3-4 m, and the heat transfer coefficient is 10-50 W / m²・K.

5. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S4, the heating power of the medium temperature zone (7) is 10-20 kilowatts, the thermal radiation coefficient of the medium temperature zone (7) is 0.8-0.9, the air circulation speed of the medium temperature zone (7) is 3-5 meters per second, the initial temperature of the water meter entering the medium temperature zone (7) is 200-250°C, the temperature uniformity of the medium temperature zone (7) is within ±10°C, the surface temperature of the heating element of the medium temperature zone (7) is 500-700°C, the temperature gradient between the medium temperature zone (7) and the low temperature zone (5) is 50-100°C / meter, and the heating rate of the water meter in the medium temperature zone (7) is 20-30°C / minute.

6. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S5, the wind speed of the third air curtain is 10-15 m / s, the temperature of the high-temperature sintering zone (9) is 700-900°C, the heating methods of the high-temperature sintering zone (9) include electric heating and gas heating, the residence time of the water meter in the high-temperature sintering zone (9) is 10 minutes, the temperature difference of the temperature uniformity of the high-temperature sintering zone (9) is controlled within ±5°C, the micro-positive pressure of the furnace pressure of the high-temperature sintering zone (9) is 10-50 Pa, the thermal radiation intensity of the high-temperature sintering zone (9) is 5×10^4-1×10^5 W / m², the temperature gradient between the high-temperature sintering zone (9) and the medium-temperature zone (7) is 100-200°C / m, and the high-temperature sintering zone (9) adopts a U-shaped symmetric overall length of 10 meters.

7. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S6, the temperature of the medium temperature zone (7) for preliminary cooling is 400-500°C, the residence time of the water meter shell in the medium temperature zone (7) for preliminary cooling is 2-4 minutes, the cooling medium of the medium temperature zone (7) includes air, the flow rate of the cooling medium is 8-12 m / s, the heat exchange coefficient is 30-80 W / m²・K, and the temperature gradient between the medium temperature zone (7) and the high temperature zone is 150-250°C / m.

8. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S7, the temperature of the low temperature zone (5) for deep cooling is 100-200°C, the residence time of the water meter shell in the low temperature zone (5) for deep cooling is 3-5 minutes, the cooling medium of the low temperature zone (5) includes air, the flow rate of the cooling medium is 5-10 m / s, the heat exchange coefficient is 20-50 W / m²・K, and the temperature gradient between the low temperature zone (5) and the medium temperature zone (7) is 100-150°C / m.

9. The method for spraying enamel on a stainless steel thin-wall water meter shell according to claim 1, characterized in that: In S8, the temperature in the safety range is lower than 50°C, the speed of the conveyor line is 0.2-0.5 m / s, the standards and indicators of the quality inspection include a coating thickness tolerance of ±0.05 mm, a surface roughness Ra value of less than 1.6 μm, and a light intensity of 800-1200 lux for the appearance inspection.

10. A stainless steel thin-walled water meter shell enamel spraying and firing device, applied to a stainless steel thin-walled water meter shell enamel spraying and firing method according to any one of claims 1 to 9, comprising a water meter upper line (1), characterized in that: The water meter upper line (1) is connected to a hanging conveyor chain (2), the water meter upper line (1) is connected to a dry powder room (3) through the hanging conveyor chain (2), the dry powder room (3) is connected to a first set of air curtains (4) through the hanging conveyor chain (2), a second set of air curtains (6) is arranged at the rear of the first set of air curtains (4), a low temperature zone (5) is arranged in the middle of the first set of air curtains (4) and the second set of air curtains (6), the length of the low temperature zone (5) is 4 meters, the first set of air curtains (4) and the second set of air curtains (6) are each arranged on the left and right sides of the low temperature zone (5), and the middle is separated by a wall, a third set of air curtains (8) is arranged at the rear of the second set of air curtains (6), and the second set of air curtains (6) and A medium temperature zone (7) is arranged in the middle of the third group of air curtains (8), and the length of the medium temperature zone (7) is 4 meters. A high temperature sintering zone (9) is arranged at the rear side of the third group of air curtains (8), and the high temperature sintering zone (9) is U-shaped, and the U-shaped symmetrical length of the high temperature sintering zone (9) is 10 meters. The third group of air curtains (8) are arranged with one group on each side, distributed on the left and right sides of the high temperature sintering zone (9). The hanging conveyor chain (2) is coiled inside the high temperature sintering zone (9) and enters from the left side of the U shape and exits from the right side. The hanging conveyor chain (2) is connected to a uniform speed conveyor chain (10), and the uniform speed conveyor chain (10) is connected to a cooling lower line (11), and the cooling lower line (11) is connected to the water meter upper line (1).

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