Hot dip galvanizing low carbon explosion-proof system

Abstract

The utility model discloses a kind of hot-dip galvanizing low-carbon explosion-proof systems, including auxiliary plating pool and zinc pot, the auxiliary plating pool and zinc pot between having transfer area, the side of zinc pot has smoke collection system, the smoke collection system is connected with pipeline, the transfer area has air inlet, the pipeline end away from zinc pot is communicated with the air inlet.Using the above scheme, the waste heat of zinc pot flue gas is fully utilized, without consuming additional fossil energy or electric energy for heating, greatly reducing production energy consumption and carbon dioxide emissions, while having the effects of efficient zinc explosion removal, improving galvanizing quality and efficiency, low operating cost and safety and reliability.

Description

Technical Field

[0001] This utility model belongs to the field of metal surface treatment technology, specifically relating to a hot-dip galvanizing low-carbon explosion-proof system. Background Technology

[0002] Hot-dip galvanizing is one of the main methods for long-term corrosion protection of steel products. Its process typically includes pickling, washing, fluxing, and hot-dip galvanizing. In the fluxing stage, steel workpieces are immersed in a fluxing solution composed of ZnCl2 and NH4Cl to form a protective film on their surface, preventing excessive oxidation during subsequent drying and galvanizing. However, a significant problem exists in current production processes: excess flux remains on the surface of the workpiece after fluxing, especially in rainy weather, forming a significant flux film. When the workpiece enters the zinc bath at approximately 450°C, the residual flux (NH4Cl) rapidly decomposes upon heating, producing large amounts of ammonia (NH3) and hydrogen chloride (HCl) gases. These gases are trapped in the molten zinc and, upon approaching the zinc surface, expand and escape instantly, causing a violent "zinc explosion." This explosion not only causes zinc dross to splatter, posing serious safety hazards and damaging the working environment, but also leads to increased zinc consumption and decreased coating quality (resulting in missed plating and defects), among other problems.

[0003] Currently, in the mass hot-dip galvanizing industry, the common practice is to add "anti-explosion agents" to the flux. While this method can suppress zinc explosions to some extent, its effectiveness is unstable and greatly affected by workpiece shape and operation. Furthermore, as an additional chemical substance, the additive accelerates flux aging, may increase zinc dross, and affect coating quality, resulting in high long-term costs. A small number of companies use gas-fired or electrically heated drying ovens to pre-dry workpieces after flux plating to remove residual moisture and flux. Although this method is effective, it consumes a large amount of primary energy (natural gas or electricity), resulting in high operating costs and directly increasing carbon emissions during production, which does not meet current green and low-carbon manufacturing requirements.

[0004] In addition, there are also explosion-proof designs that use structural improvements, such as the patent with patent number "CN213388852U" entitled "A Galvanizing Fixture for Angle Steel for Transmission Lines". This patent mainly uses an isolation method to prevent zinc explosions. The applicant found in his research that although this type of structure can prevent injury to operators, zinc explosions can still occur, affecting the galvanizing quality and failing to fundamentally solve the zinc explosion problem.

[0005] Therefore, there is an urgent need to develop a new technology and device that can effectively eliminate zinc explosion, significantly save costs, and reduce energy consumption and carbon emissions. Utility Model Content

[0006] In view of this, the present invention provides a low-carbon explosion-proof hot-dip galvanizing system to solve the problem of zinc explosion that easily occurs in existing hot-dip galvanizing technology.

[0007] The technical solution is as follows: A hot-dip galvanizing low-carbon explosion-proof system includes a fluxing bath and a zinc pot. The key features are: a transfer zone between the fluxing bath and the zinc pot; a smoke collection system at the top of the zinc pot; a pipe connected to the smoke collection system; an air inlet in the transfer zone; and the end of the pipe away from the zinc pot connected to the air inlet.

[0008] By employing the above method, the hot air generated by the zinc pot is fully utilized to purge the workpieces in the transfer zone, promoting the formation of a high-temperature, dry transfer zone. This accelerates the evaporation of moisture from the flux film on the workpiece surface and simultaneously promotes the crystallization and solidification of the NH4Cl·ZnCl2 double salt. The workpiece surface thus becomes dry and uniform, leaving only a thin, dense solid flux film. When the workpiece subsequently enters the zinc pot, the solid flux film melts smoothly and reacts with the molten zinc, without generating gas due to the violent decomposition of residual droplets. This eliminates zinc explosion at its source, resulting in a significant and stable effect. Furthermore, this process also preheats the workpiece, further improving galvanizing efficiency and quality. The entire process requires no additional fossil fuels or electricity for heating, significantly reducing production energy consumption and carbon dioxide emissions, aligning with the national "dual-carbon" strategic goals.

[0009] Preferably, the pipeline is equipped with at least one high-temperature resistant blower A. Using the above scheme, active exhaust with blowers allows for better control of the purging air velocity and also allows for better arrangement of the relative positions of the zinc pot and the transfer area.

[0010] Preferably, the pipeline has a large-diameter section and a small-diameter section. The large-diameter section is connected to the smoke collection system, and the small-diameter section is connected to the air inlet. A high-temperature resistant blower A is installed in the large-diameter section, and a high-temperature resistant blower B is installed in the small-diameter section. Both high-temperature resistant blowers A and B are equipped with speed control valves. This design is more conducive to the collection of high-temperature flue gas from the zinc pot and the control of air intake in the transfer zone, meeting more adjustment needs.

[0011] Preferably, a filter device is installed inside the pipeline, located between the high-temperature blower A and the high-temperature blower B. With this design, the filter device primarily filters dust and impurities in the high-temperature flue gas, preventing them from adhering to the surface of the workpiece in the transfer area and affecting the subsequent galvanizing operation.

[0012] Preferably, the filtration device has a multi-layer activated carbon fiber mesh structure. This design provides good throughput and adsorption performance.

[0013] Preferably, the air inlets are evenly distributed on the circumferential sidewalls of the transfer zone. This design creates a high-temperature, dry transfer zone, achieving better surface purging, avoiding localized omissions, and further improving the zinc explosion prevention effect.

[0014] Preferably, the pipe is an insulated pipe. Adopting this solution can reduce heat loss, fully utilize collected heat, and ensure the normal operation of the system.

[0015] Preferably, the plating bath, transfer zone, and zinc pot are located on the same travel path of the same trolley.

[0016] Compared with the prior art, the beneficial effects of this utility model are: The method of using the hot-dip galvanizing low-carbon explosion-proof system provided by this utility model: 1. Low carbon and environmentally friendly: It makes full use of the waste heat of the zinc pot flue gas, without the need to consume additional fossil energy or electricity for heating, which greatly reduces production energy consumption and carbon dioxide emissions, in line with the national "dual carbon" strategic goal.

[0017] 2. Highly efficient zinc explosion prevention: Targeted purging is performed at the most critical stage after fluxing and before entering the zinc bath, eliminating the source of gases that cause zinc explosions at the source. The effect is significant and stable, greatly improving coating quality and product qualification rate.

[0018] 3. Improve galvanizing quality and efficiency: While eliminating surface moisture in the transfer zone, the hot air preheats the workpiece, increasing the surface temperature and preventing the zinc liquid from cooling and solidifying too quickly due to excessively cold surface temperature, which could lead to localized excessive zinc layer thickness or sagging. In addition, when the workpiece temperature is too low, it takes longer to reach the zinc liquid reaction temperature, extending the immersion time. Therefore, while eliminating zinc bursts, it also helps to improve galvanizing quality and efficiency.

[0019] 4. Low operating cost: It operates with almost zero energy consumption, requiring only a small amount of fan power, and has a short payback period for equipment investment.

[0020] 5. Safe and reliable: It eliminates the safety hazards caused by zinc explosions, improves the working environment in the workshop, and the collected waste heat is a low-temperature heat source, with no risk of fire or overheating. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a front view of the air outlet in the transfer area; Figure 3 This is a side view of the air outlet in the transfer zone. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] refer to Figures 1 to 3 The hot-dip galvanizing low-carbon explosion-proof system shown mainly includes a fluxing tank 1 and a zinc pot 3. The key feature of this application is the separate transfer zone 2 located between the fluxing tank 1 and the zinc pot 3. In practice, the fluxing tank 1, transfer zone 2, and zinc pot 3 are located on the same traveling line of a crane, allowing the workpiece to be transferred between three positions using the same crane. In this application, the fume collection system is located above the zinc pot 3 and consists of a fume outlet and a collection pipe. The upper side wall of the zinc pot has a fume outlet connected to a collection pipe surrounding the outer wall of the zinc pot. The collection pipe is then connected to a pipe 5. The transfer zone 2 has an air inlet 20, and the end of the pipe 5 furthest from the zinc pot 3 is connected to the air inlet 20.

[0024] In this embodiment, at least a high-temperature resistant blower A50 is provided on the pipe 5. After the high-temperature resistant blower A50 is provided, hot air can be actively drawn in and sent to the transfer area 2. The high-temperature resistant type is adopted, which helps to ensure its continuous operation under high-temperature conditions and extend its overall service life.

[0025] like Figure 1 As shown, the pipe 5 has a large-diameter section 51 and a small-diameter section 52. The diameter of the large-diameter section 51 is larger than that of the small-diameter section 52. The large-diameter section 51 is connected to the smoke collection system, and the small-diameter section 52 is connected to the air inlet 20. The large-diameter section 51 is equipped with a high-temperature resistant blower A50, and the small-diameter section 52 is equipped with a high-temperature resistant blower B53. Both the high-temperature resistant blower A50 and the high-temperature resistant blower B53 have speed control valves. The speed control valves have three speed control functions: fast, medium, and slow. The specifications of the high-temperature blower A50 are relatively larger than those of the high-temperature resistant blower B53.

[0026] In addition, a filter device 4 is installed inside the pipe 5, as shown in the figure. The filter device 4 is located between the high-temperature resistant blower A50 and the high-temperature resistant blower B53. In specific implementation, the filter device 4 is a multi-layer activated carbon fiber mesh structure.

[0027] refer to Figure 2 and Figure 3 The air inlets 20 are evenly distributed on the circumferential sidewalls of the transfer zone 2. In this embodiment, the transfer zone 2 is generally rectangular. Branch pipes are connected to the air inlets on the transfer zone 2. All branch pipes 22 are connected to the end of the pipe 5. It should be noted that the axis of the branch pipe in the middle of the height direction of the transfer zone 2 is perpendicular to the corresponding sidewall. The branch pipe above the middle is inclined downward, and the branch pipe below the middle is inclined upward. The inclination angle is 30°~60°, which changes the incident angle of hot air entering the transfer zone. In this embodiment, it is preferably 45°. This is more conducive to the hot air entering the transfer zone 2 and acting evenly on the workpiece. The upward and downward impact prolongs the residence time of the hot air in the transfer zone, promoting the formation of a high-temperature and dry transfer zone. This can better maintain the temperature and dryness in the transfer zone, thereby achieving a better preheating effect.

[0028] To achieve better and more comprehensive purging of the workpiece surface, a spiral nozzle is rotatably installed at the outlet end of the branch pipe. The spiral nozzle is coaxial with the branch pipe 22 and has at least two spiral-shaped air holes. When gas passes through, it drives the spiral nozzle to rotate, thus forming a spiral airflow based on the initial incident angle. This expands the coverage area of ​​the airflow at a suitable velocity, ensuring that the workpiece receives a relatively uniform purging effect, which is beneficial to improving product quality consistency. Of course, to ensure rotational stability, three air holes are preferred, and they are evenly distributed circumferentially around the nozzle.

[0029] To further improve the utilization efficiency of the heat generated by the zinc pot, in this embodiment, pipe 5 is an insulated pipe. Specifically, the main body is an aluminum alloy pipe or a galvanized iron pipe, and the outside is covered with insulation material, such as rock wool, glass wool or polyurethane foam. In this application, aluminum alloy pipe is preferred as the main body of the pipe, and polyurethane foam is used for insulation.

[0030] On the other hand, it is important to note that all connection points should be sealed to improve overall airtightness, effectively prevent the leakage of high-temperature gas, and ensure that the final air supply temperature meets the design requirements. Preferably, the system airtightness is less than 100 ml / min.

[0031] refer to Figures 1 to 3 The hot-dip galvanizing low-carbon explosion-proof system of this application is used as follows: the fluxing tank 1 contains a fluxing solution, which is typically composed of ZnCl2 and NH4Cl, and is operated according to the following steps: Step S1: Start the zinc pot 3 to bring the zinc liquid to the working temperature. At the same time, the high-temperature blower A50 and / or the high-temperature blower B53 work to send the high-temperature hot air into the transfer zone 2. During this process, the blowers can work alone to control the wind speed or work together to control the wind speed.

[0032] Step S2: The workpiece to be galvanized is hung on a hanger and then lifted into the galvanizing bath 1 by a crane to form a protective film.

[0033] Step S3: The zinc-coated workpiece is hoisted into the transfer zone 2 after the galvanizing process is completed. The dwell time is determined according to the ambient temperature and humidity to remove the moisture from the liquid film on the workpiece surface.

[0034] Step S4: The workpiece to be galvanized in the transfer area 2 is hoisted into the zinc pot 3 for galvanizing.

[0035] The main working principle is as follows: the high-temperature flue gas (typically 100~200℃) generated by the continuous operation of the zinc pot is collected through a flue gas collection system. The high-temperature flue gas and ambient air, under the action of an exhaust fan, pass through a filter and enter the insulated pipe. This hot air is then transported to the transfer area through the insulated pipe and, via appropriately arranged branch nozzles, is directly blown at a certain wind speed (5~12 m / s) and temperature (50~70℃) onto the surface of the workpiece, which has just been removed from the flux solution and is at room temperature (30~40℃). The 50~70℃ hot air accelerates the evaporation of moisture in the flux film on the workpiece surface and simultaneously promotes the crystallization and solidification of the NH4Cl·ZnCl2 double salt. The workpiece surface thus becomes dry and uniform, leaving only a thin and dense solid flux film. This process also preheats the workpiece, which is beneficial for improving the subsequent zinc plating efficiency.

[0036] When the workpiece is subsequently placed into the zinc bath, the solid flux will melt smoothly and react with the zinc liquid without generating gas due to the violent decomposition of residual droplets. This essentially eliminates the zinc explosion phenomenon. At the same time, preheating increases the workpiece temperature, which can effectively prevent the zinc liquid from cooling and solidifying rapidly due to excessively low surface temperature, resulting in excessively thick zinc layers or drips. This is beneficial for improving the quality and efficiency of galvanizing.

[0037] Finally, it should be noted that the above description is merely a preferred embodiment of the present utility model. Those skilled in the art, under the guidance of the present utility model, can make various similar representations without departing from the spirit and claims of the present utility model, and such modifications all fall within the protection scope of the present utility model.

Claims

1. A hot-dip galvanizing low-carbon explosion-proof system, comprising a fluxing bath (1) and a zinc pot (3), characterized in that: There is a transfer zone (2) between the plating bath (1) and the zinc pot (3). The upper part of the zinc pot (3) has a smoke collection system, which is connected to a pipe (5). The transfer zone (2) has an air inlet (20). The end of the pipe (5) away from the zinc pot (3) is connected to the air inlet (20).

2. The hot dip galvannealed low-carbon blast protection system of claim 1, wherein: At least one high-temperature resistant blower A (50) is installed on the pipeline (5).

3. A hot dip galvanised low-carbon blast protection system according to claim 1 or 2, c h a r a c t e r i s e d i n that: The pipe (5) has a large diameter section (51) and a small diameter section (52). The large diameter section (51) is connected to the smoke collection system, and the small diameter section (52) is connected to the air inlet (20). The large diameter section (51) is equipped with a high temperature resistant blower A (50), and the small diameter section (52) is equipped with a high temperature resistant blower B (53). Both the high temperature resistant blower A (50) and the high temperature resistant blower B (53) have speed control valves.

4. The hot dip galvannealed low-carbon blast protection system of claim 3, wherein: The pipe (5) is equipped with a filter device (4), which is located between the high-temperature blower A (50) and the high-temperature blower B (53).

5. The hot dip galvannealed low-carbon blast protection system of claim 4, wherein: The filtration device (4) has a multi-layer activated carbon fiber mesh structure.

6. The hot dip galvanised low-carbon blast protection system of claim 1 or 2, wherein: The air inlets (20) are evenly distributed on the circumferential sidewalls of the transfer zone (2).

7. The hot dip galvanised low-carbon popper system according to claim 6, characterized in that: The pipe (5) is an insulated pipe.

8. The hot dip galvanizing low-carbon pop system according to claim 1 or 2, characterized in that: The plating bath (1), the transfer zone (2), and the zinc pot (3) are located on the same moving line of the same trolley.

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