An emission-free pre-treatment device

Abstract

This utility model discloses a zero-emission pretreatment device, including a suspended conveyor, a pretreatment chamber, a spraying device, a water circulation device, and a hot air circulation device. The pretreatment chamber is sequentially arranged with a spraying zone, a transition zone, and a drying zone. Collection tanks are respectively provided at the bottom of the spraying zone and the transition zone. Two spraying devices are symmetrically arranged on opposite inner walls of the spraying zone. Each spraying device includes a first water supply pipe, a swing mechanism, and a second water supply pipe. Each first water supply pipe is provided with several first nozzles facing the side wall of the workpiece. The output end of the swing mechanism is connected to the second water supply pipe, and the end of the second water supply pipe is provided with a second nozzle facing the bottom of the workpiece. The inlet of the water circulation device is connected to the drain pipe of the collection tank, and its outlet is connected to the inlet of each spraying device. The hot air circulation device is located in the drying zone. The zero-emission pretreatment device provided by this utility model achieves full-coverage spraying of the workpiece and, with the addition of a transition zone, facilitates the recovery of droplets from the workpiece surface.

Description

Technical Field

[0001] This utility model relates to the field of pre-treatment technology for coating, and in particular to a zero-emission pre-treatment device. Background Technology

[0002] In the field of pre-coating treatment, traditional pre-coating processes for sheet metal often rely on water washing to remove impurities and residual treatment agents from the sheet metal surface, which can easily generate a large amount of pre-coating wastewater. If not handled properly, it can cause environmental pollution.

[0003] There is a zero-emission pretreatment process to solve this problem. This process uses a special treatment agent to clean the board. After the treatment agent reacts with the surface of the board, it forms a conversion film layer, which not only improves the adhesion between the paint and the substrate during subsequent painting, but also prevents rust on the board in the bare film state. At the same time, this process does not require additional water washing, and the cleaning wastewater can be recycled after purification, achieving zero wastewater discharge. In the pretreatment process of sheet metal parts, overhead conveyor systems are commonly used for continuous workpiece transport. For workpieces on overhead conveyor systems, the industry typically employs spraying for surface cleaning. Common spraying structures involve placing spray devices on both sides of the workpiece transport path, spraying treatment agents or cleaning solutions onto the workpiece surface through nozzles on both sides. However, workpieces (especially complex parts) often have recesses or grooves on their bottoms. The spray paths on both sides are insufficient to cover these bottom recesses, creating cleaning dead zones. This prevents the specialized treatment agent from fully contacting the bottom recessed surfaces, resulting in incomplete cleaning. Residual impurities affect the quality of the conversion coating, leading to insufficient paint adhesion, localized corrosion, and other problems in subsequent coating processes, severely reducing the overall coating quality of the workpiece.

[0004] It is evident that existing technologies still need improvement and enhancement. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a zero-emission pretreatment device, which aims to solve the technical problem that the bottom of the workpiece has a cleaning dead corner when only the two-sided spraying method is used in the prior art, resulting in incomplete cleaning.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A zero-emission pretreatment device, comprising: A suspended conveyor device for transporting workpieces along a designated path; The pretreatment room is equipped with a spray zone, a transition zone and a drying zone in sequence along the conveying direction of the workpiece; the bottom of the spray zone and the transition zone are respectively equipped with a collection tank with a funnel-shaped cross section, and the bottom of the collection tank is equipped with a drain pipe; the pretreatment room is equipped with a foot pedal grid located above the collection tank. Two spraying devices are symmetrically arranged on opposite inner walls of the spraying area; each spraying device includes several first water supply pipes, several swing mechanisms and several second water supply pipes, and each first water supply pipe is provided with several first nozzles facing the side wall of the workpiece; the output end of the swing mechanism is connected to the second water supply pipe for adjusting the installation angle of the second water supply pipe, the second water supply pipe is located above the foot slab grid, and its end is provided with a second nozzle facing the bottom of the workpiece; A water circulation device, wherein the inlet of the water circulation device is connected to the drain pipe, and its outlet is connected to the inlet of each spray device; and A hot air circulation device, located in the drying area, is used to spray hot air toward the workpiece.

[0007] Furthermore, the upper end of the first water supply pipe is connected to a third water supply pipe extending obliquely upward, and the third water supply pipe is provided with a plurality of third nozzles; the second water supply pipe is a flexible hose, and one end of the second water supply pipe is connected to the lower end of the first water supply pipe.

[0008] Furthermore, the first nozzles on two adjacent first water supply pipes are staggered; the third nozzles on two adjacent third water supply pipes are staggered.

[0009] Furthermore, the swing mechanism includes a first hinge seat, a telescopic rod, a second hinge seat, and a support rod. Both the first and second hinge seats are fixed within the spray area. The telescopic rod includes a fixed rod and an extension rod slidably connected to the fixed rod. One end of the fixed rod is hinged to the first hinge seat, and one end of the extension rod is connected to the end of the second water supply pipe. One end of the support rod is hinged to the second hinge seat, and the other end is slidably connected to the fixed rod.

[0010] Furthermore, the fixing rod is provided with first adjustment holes arranged at intervals along its length direction, and a slide block is slidably connected to the fixing rod. The slide block is detachably connected to any of the first adjustment holes on the fixing rod by a first screw, and the slide block is hinged to the end of the support rod.

[0011] Furthermore, it also includes an adjusting plate with an arc-shaped groove; the end of the extension rod is provided with a short shaft and a second screw, the adjusting plate is rotatably connected to the short shaft, and the second screw slides along the arc-shaped groove; the end of the second water pipe is fixed to the adjusting plate by a pipe clamp.

[0012] Furthermore, the hot air circulation device includes a first air inlet pipe group, a first air outlet pipe group, a second air inlet pipe group, a second air outlet pipe group, and a hot air supply unit. The air outlet end of the hot air supply unit is connected to the first air inlet pipe group. The first air inlet pipe group and the first air outlet pipe group are respectively located on opposite inner sides of the drying zone. The first air outlet pipe group is connected to the second air inlet pipe group through a pipe. The second air inlet pipe group and the second air outlet pipe group are respectively located on opposite inner sides of the transition zone. The second air outlet pipe group is connected to the return air end of the hot air supply unit.

[0013] Furthermore, the second air inlet duct is positioned near the spray area; the second air outlet duct is positioned near the drying area.

[0014] Furthermore, the output end of the suspended conveyor is provided with a C-shaped frame, and the bottom of the C-shaped frame is provided with a hanger for suspending workpieces; the pretreatment chamber also includes two guide plates that are inclined downwards towards the two inner side walls respectively, and a first clearance groove is formed between the two guide plates; the top of the pretreatment chamber is provided with a second clearance groove extending along its length; the first clearance groove and the second clearance groove are not on the same vertical plane, the hanger can move along the first clearance groove, and the C-shaped frame can move along the second clearance groove.

[0015] Beneficial effects: This utility model provides a pretreatment device with zero emissions, which has the following beneficial effects: (1) By adjusting the angle of the second water supply pipe and the second nozzle through the swing mechanism, the bottom depression and groove of the workpiece can be covered in a targeted manner. Combined with the spraying effect of the first water supply pipe on the side wall of the workpiece, the side wall and bottom of the workpiece are fully covered by spraying, effectively eliminating the blind spots of traditional spraying; (2) After the addition of the transition zone, most of the liquid droplets attached to the surface of the workpiece will drip into the bottom collection tank for recycling, which can improve the recovery rate of the treatment agent and reduce the amount of liquid droplets carried by the workpiece into the drying zone, thereby reducing the drying load; (3) A foot grid is set above the collection tank in the pretreatment room to facilitate the staff to enter each area for maintenance; and the swing mechanism can store the second water supply pipe in the inner wall of the spraying area without obstructing movement. Attached Figure Description

[0016] Figure 1 This is a side sectional view of the spray zone in the emission-free pretreatment device provided by this utility model; Figure 2 for Figure 1 Enlarged view at point M; Figure 3 A structural diagram of the swing mechanism in the emission-free pretreatment device provided by this utility model; Figure 4 Exploded view of the swing mechanism in the emission-free pretreatment device provided by this utility model; Figure 5 Partial cross-sectional view of the oscillating mechanism in the emission-free pretreatment device provided by this utility model Figure 1 ; Figure 6 Partial cross-sectional view of the oscillating mechanism in the emission-free pretreatment device provided by this utility model Figure 2 ; Figure 7 This is a top sectional view of the emission-free pretreatment device provided by this utility model; Figure 8 This is a side sectional view of the drying zone in the emission-free pretreatment device provided by this utility model; Figure 9 The structural diagram of the first air inlet duct assembly in the emission-free pretreatment device provided by this utility model.

[0017] Reference numerals: 1. Suspended conveyor; 11. C-frame; 12. Hanger; 13. Conveyor track; 14. Roller assembly; 15. Drive chain; 2. Pre-treatment chamber; 21. Spraying area; 22. Transition area; 23. Drying area; 24. Collection tank; 241. Drain pipe; 25. Foot grating; 26. Guide plate; 261. First clearance groove; 27. Second clearance groove; 3. Spraying device; 31. First water supply pipe; 311. First nozzle; 32. Swinging mechanism; 321. First hinge seat; 322. Telescopic rod; 3221. Fixed rod; 3222. Extending rod; 3222. First adjusting hole; 3223. Second chute; 3224. Second adjusting hole; 3225. Short shaft; 3226. Second screw; 32 27, Third screw 3228, Second hinge seat 323, Support rod 324, Adjusting plate 325, Arc groove 3251, Slide 326, First slide groove 3261, First screw 327, Second water supply pipe 33, Second nozzle 331, Third water supply pipe 34, Third nozzle 341, Water circulation device 4, Oil-water separator 41, First circulation pump 42, Storage tank 43, Second circulation pump 44, Dosing tank 45, Third circulation pump 46, Hot air circulation device 5, First air inlet pipe group 51, Ventilation pipe 511, Air outlet 512, First air outlet pipe group 52, Second air inlet pipe group 53, Second air outlet pipe group 54, Hot air supply unit 55. Detailed Implementation

[0018] This utility model provides a zero-emission pretreatment device. To make the purpose, technical solution, and effects of this utility model clearer and more explicit, the following describes this utility model in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0019] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on this utility model. Furthermore, "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0020] Please see Figures 1 to 9As shown, this utility model provides a zero-emission pretreatment device, including: a suspended conveyor 1, a pretreatment chamber 2, two spray devices 3, a water circulation device 4, and a hot air circulation device 5. The suspended conveyor 1 is used to transport workpieces along a designated path; the pretreatment chamber 2 is arranged with a spray zone 21, a transition zone 22, and a drying zone 23 sequentially along the conveying direction of the workpieces; the bottom of the spray zone 21 and the transition zone 22 are respectively provided with a collection trough 24 with a funnel-shaped cross-section, and the bottom of the collection trough 24 is provided with a drain pipe 241; the pretreatment chamber 2 is provided with a foot pedal grid 25 located above the collection trough 24; the two spray devices 3 are symmetrically arranged on the two opposite inner walls of the spray zone 21; each The spraying device 3 includes several first water supply pipes 31, several swing mechanisms 32, and several second water supply pipes 33. Each first water supply pipe 31 is provided with several first nozzles 311 facing the side wall of the workpiece. The output end of the swing mechanism 32 is connected to the second water supply pipe 33 and is used to adjust the installation angle of the second water supply pipe 33. The second water supply pipe 33 is located above the foot tread grating 25, and its end is provided with a second nozzle 331 facing the bottom of the workpiece. A water circulation device 4 is provided, with its inlet end connected to the drain pipe 241 and its outlet end connected to the inlet end of each spraying device 3. A hot air circulation device 5 is provided in the drying zone 23 and is used to spray hot air toward the workpiece.

[0021] Before the pretreatment work, the swing mechanism 32 is pre-adjusted according to the structure of the bottom of the workpiece. The installation position of the second water supply pipe 33 is adjusted by the swing mechanism 32, so that the spray range of the second nozzle 331 covers the bottom of the workpiece and the recessed and grooved areas of the bottom. During operation, the suspended conveyor 1 sequentially delivers the workpieces to be processed into the pretreatment chamber 2 along a designated path. The workpieces first enter the spray zone 21 inside the pretreatment chamber 2. Two symmetrical spray devices 3 located on opposite inner walls of the spray zone 21 work synchronously. The first water supply pipe 31 of each spray device 3 sprays the treatment agent mixture onto the side wall of the workpiece through the first nozzle 311, and the second water supply pipe 33 sprays the treatment agent mixture onto the bottom of the workpiece through the second nozzle 331, achieving full coverage spraying of the side wall and bottom of the workpiece. The sprayed treatment agent mixture converges along the funnel-shaped collection trough 24 at the bottom of the spray zone 21 and flows into the water circulation device 4 through the drain pipe 241 at the bottom of the collection trough 24. After purifying the treatment agent mixture, the water circulation device 4 transports it back to the inlet of each spray device 3 from the outlet end, forming a closed-loop circulation of the treatment agent mixture. After the workpiece has been sprayed, it enters the transition zone 22 via the suspended conveyor 1. By setting the transition zone 22, most of the droplets adhering to the surface of the workpiece fall into the collection tank 24 at the bottom. These droplets also flow into the water circulation device 4, preventing the workpiece from carrying too many droplets into the drying zone 23 and increasing the drying load. Subsequently, the workpiece enters the drying zone 23, where the hot air circulation device 5 sprays hot air onto the workpiece to dry the treatment agent mixture on the surface of the workpiece, thus completing the zero-emission pretreatment process for the workpiece.

[0022] Compared to existing technologies, the oscillating mechanism 32 adjusts the angle of the second water pipe 33 and the second spray nozzle 331, allowing for targeted coverage of areas inaccessible to traditional side spraying, such as bottom depressions and grooves of the workpiece. This eliminates cleaning dead zones and ensures uniform adhesion and thorough cleaning of the workpiece surface treatment agent. Simultaneously, the addition of a transition zone 22 improves the recovery rate of the treatment agent and effectively reduces the drying load. Furthermore, the footrest grating 25 located above the collection tank 24 in the pretreatment chamber 2 facilitates personnel access to the spray zone 21, transition zone 22, and drying zone 23 for equipment maintenance. The oscillating mechanism 32 also allows the second water pipe 33 to be retracted into the inner wall of the spray zone 21, without obstructing personnel movement.

[0023] The aforementioned specialized treatment agent is existing technology and can be the phosphorus-free JW series conversion agent, suitable for surface pretreatment of various metal substrates such as carbon steel, galvanized sheet, and aluminum. During use, the treatment agent must be mixed with industrial water at a specific ratio (refer to the product technical manual for details) according to the type of substrate and the actual condition of surface oil contamination, forming a treatment agent mixture. Thorough stirring is necessary during mixing to ensure uniform concentration of the treatment agent mixture, avoiding uneven concentration that could affect the quality of the conversion film formation. The mixing of the treatment agent and industrial water takes place within the water circulation device 4.

[0024] In the above, such as Figure 7 As shown, the water circulation device 4 includes an oil-water separator 41, a first circulation pump 42, a storage tank 43, a second circulation pump 44, a dosing tank 45, and a third circulation pump 46 connected in sequence. The drain pipe 241 is connected to the water inlet of the oil-water separator 41, and the water outlet of the third circulation pump 46 is connected to the water inlet of the two spray devices 3.

[0025] Among them, the oil-water separator 41 is existing technology, used to separate oil and impurities in the mixture of recovery treatment agent; when the water circulation device 4 is working, the mixture of treatment agent in the spray zone 21 and the collection tank 24 of the transition zone 22 first flows into the oil-water separator 41 through the drain pipe 241. After separation and purification, it is transported to the storage tank 43 by the first circulation pump 42 for temporary storage; the storage tank 43 can allow the recovered liquid to stand for a short time to further achieve the precipitation and separation of trace impurities; then the recovered liquid after standing is sent to the dosing tank 45 by the second circulation pump 44. The staff can add special treatment agent or adjust the spray concentration according to the actual situation. The dosing tank 45 is equipped with a stirring paddle, which can fully mix the treatment agent and the recovered liquid evenly; finally, the evenly mixed treatment agent is transported to the water inlet of the two spray devices 3 by the third circulation pump 46 and reused for spraying the workpiece, forming a closed loop circulation of special treatment agent.

[0026] In a preferred embodiment, see [reference] Figure 1The upper end of the first water supply pipe 31 is connected to a third water supply pipe 34 extending obliquely upwards. The third water supply pipe 34 is equipped with several third nozzles 341. These third nozzles 341 face the top of the workpiece, enabling all-around spraying of the upper area, top edge, and protruding structures of the workpiece, thus compensating for the spray blind spots created by the first nozzles 311. The second water supply pipe 33 is a flexible hose, with one end connected to the lower end of the first water supply pipe 31. The flexibility of the hose allows for precise adjustment of the angle of the swing mechanism 32. When the swing mechanism 32 adjusts the angle of the second water supply pipe 33 to align with the recesses or grooves at the bottom of the workpiece, the hose deforms flexibly with the adjustment, ensuring that the second nozzles 331 consistently and stably deliver the treatment agent and accurately act on the area to be cleaned at the bottom of the workpiece.

[0027] Furthermore, the first nozzles 311 on the two adjacent first water supply pipes 31 are staggered; the third nozzles 341 on the two adjacent third water supply pipes 34 are staggered, effectively avoiding local overlap or gaps in the spray range of adjacent nozzles; ensuring that the treatment agent can uniformly cover the surface area of ​​the workpiece, providing a stable guarantee for the uniform formation of the subsequent conversion film layer.

[0028] Similarly, to further improve the uniformity of spraying at the bottom of the workpiece, the installation angles of two adjacent second water pipes 33 are different. Based on the angle adjustment function of the aforementioned swing mechanism 32, the installation angles of different second water pipes 33 can be adjusted according to the actual structure of the depressions and grooves at the bottom of the workpiece to ensure sufficient spraying of different areas, thereby ensuring that each depression and groove can fully contact the treatment agent.

[0029] In a preferred embodiment, see [reference] Figure 3 , 4The swing mechanism 32 includes a first hinge seat 321, a telescopic rod 322, a second hinge seat 323, and a support rod 324. The first hinge seat 321 and the second hinge seat 323 are both fixed in the spray area 21. The telescopic rod 322 includes a fixed rod 3221 and an extension rod 3222 that is slidably connected to the fixed rod 3221. One end of the fixed rod 3221 is hinged to the first hinge seat 321, and one end of the extension rod 3222 is connected to the end of the second water pipe 33. One end of the support rod 324 is hinged to the second hinge seat 323, and the other end is slidably connected to the fixed rod 3221. When the installation position of the second nozzle 331 needs to be adjusted, the extension rod 3222 slides axially along the fixed rod 3221, simultaneously moving the end of the second water supply pipe 33. During this process, the installation angle of the fixed rod 3221 is adjusted, causing the fixed rod 3221 to rotate around the first hinge seat 321. One end of the support rod 324 slides along the fixed rod 3221 as it rotates, while the other end rotates synchronously around the second hinge seat 323, forming a stable support for the fixed rod 3221, until the second water supply pipe 33 moves the second nozzle 331 to the target area such as the bottom depression or groove of the workpiece. Through the telescopic structure of the telescopic rod 322 and the stable support structure of the support rod 324 for the telescopic rod 322, the position of the second nozzle 331 can be flexibly adjusted to adapt to the cleaning needs of workpieces with different bottom structures.

[0030] Further, see Figure 4 , 6 The fixing rod 3221 is provided with first adjustment holes 3223 spaced apart along its length. A slide block 326 is slidably connected to the fixing rod 3221. The slide block 326 is detachably connected to any of the first adjustment holes 3223 on the fixing rod 3221 by a first screw 327, and the slide block 326 is hinged to the end of the support rod 324. Specifically, the first screw 327 is threaded to the slide block 326, and the first adjustment holes 3223 are all through holes. When the first screw 327 is screwed out of the first adjustment hole 3223, the slide block 326 can slide freely along the axial direction of the fixing rod 3221; when the first screw 327 is screwed into the first adjustment hole 3223, the slide block 326 can be fixed on the fixing rod 3221, so that the slide block 326 can be locked at the position of the first adjustment hole 3223 that matches the current adjustment requirement. By setting multiple spaced first adjustment holes 3223, multiple fixed points can be provided for the slide 326. The operator can flexibly adjust the connection position of the support rod 324 and the fixed rod 3221, i.e. the fixed position of the slide 326, according to the angle adjustment requirements of the second water pipe 33, thereby effectively expanding the installation position adjustment range of the second nozzle 331 and better adapting to the cleaning needs of workpieces with different bottom structures.

[0031] Specifically, see Figure 4 , 6The fixed rod 3221 has an I-shaped cross-section, and the top of the slide block 326 is provided with an inverted T-shaped first groove 3261, which is slidably connected to the lower part of the fixed rod 3221. When adjusting the position of the slide block 326, the inverted T-shaped first groove 3261 can effectively limit the lower part of the fixed rod 3221, preventing the slide block 326 from shifting laterally or detaching from the fixed rod 3221 during sliding, and ensuring that the slide block 326 always moves stably along the preset trajectory of the fixed rod 3221.

[0032] See Figure 4 , 5 The bottom of the extendable rod 3222 is provided with a T-shaped second sliding groove 3224, which is slidably connected to the upper part of the fixed rod 3221. Similarly, when adjusting the extension length of the extendable rod 3222, the T-shaped second sliding groove 3224 effectively limits the upper part of the fixed rod 3221, preventing the extendable rod 3222 from shifting laterally or detaching from the fixed rod 3221 during sliding, thereby ensuring that the extendable rod 3222 always moves stably along the axial direction of the fixed rod 3221.

[0033] In the above embodiments, see Figure 4 The fixed rod 3221 is provided with second adjustment holes 3225 spaced apart along its length. The extension rod 3222 is detachably connected to any of the second adjustment holes 3225 on the fixed rod 3221 via a third screw 3228. Specifically, the third screw 3228 is threadedly connected to the extension rod 3222, and the second adjustment holes 3225 are all through holes. When the third screw 3228 is screwed out of the second adjustment hole 3225, the extension rod 3222 can slide freely along the axial direction of the fixed rod 3221, which facilitates flexible adjustment of the extension length of the extension rod 3222 according to the bottom structure of the workpiece and the spraying requirements of the second nozzle 331. When the third screw 3228 is screwed into the second adjustment hole 3225 that matches the adjustment requirements, the extension rod 3222 can be stably fixed on the fixed rod 3221, preventing it from shifting due to the spray pressure of the treatment agent during the spraying operation. By setting multiple spaced second adjustment holes 3225 in conjunction with the third screw 3228, multiple length adjustment options are provided for the extension rod 3222. Combined with the characteristic that the second water pipe 33 is a flexible hose, the position adjustment range of the second nozzle 331 can be expanded, thereby better adapting to the bottom spraying needs of workpieces of different specifications.

[0034] In a preferred embodiment, see [reference] Figure 3 , 4It also includes an adjusting plate 325, on which an arc-shaped groove 3251 is formed; the end of the extension rod 3222 is provided with a short shaft 3226 and a second screw 3227. The adjusting plate 325 is rotatably connected to the short shaft 3226, and the second screw 3227 slides along the arc-shaped groove 3251, wherein the center of the arc-shaped groove 3251 is coaxial with the axis of the short shaft 3226; the end of the second water pipe 33 is fixed to the adjusting plate 325 by a pipe clamp. During adjustment, first loosen the second screw 3227 to push the adjusting plate 325 to rotate around the short shaft 3226. At this time, the second screw 3227 slides synchronously along the arc-shaped groove 3251 until the second water pipe 33 drives the second nozzle 331 to rotate to a position facing the target area at the bottom of the workpiece. Finally, tighten the second screw 3227 to lock the relative position of the adjusting plate 325 and the extension rod 3222. By adding the angle fine-tuning function of the second nozzle 331, it can be further adapted to the complex structure of the bottom of different workpieces, meet diverse spraying needs, and ensure thorough spraying of the bottom of the workpiece.

[0035] In a preferred embodiment, see [reference] Figure 7 , 8 The hot air circulation device 5 includes a first air inlet pipe group 51, a first air outlet pipe group 52, a second air inlet pipe group 53, a second air outlet pipe group 54, and a hot air supply unit 55. The air outlet end of the hot air supply unit 55 is connected to the first air inlet pipe group 51. The first air inlet pipe group 51 and the first air outlet pipe group 52 are respectively located on opposite inner sides of the drying zone 23. The first air outlet pipe group 52 is connected to the second air inlet pipe group 53 through a pipe. The second air inlet pipe group 53 and the second air outlet pipe group 54 are respectively located on opposite inner sides of the transition zone 22. The second air outlet pipe group 54 is connected to the return air end of the hot air supply unit 55. During hot air drying, the high-temperature hot air generated by the hot air supply unit 55 is transported to the first air inlet pipe group 51 through the pipeline. The first air inlet pipe group 51 distributes air evenly along the inner wall of the drying zone 23, drying the workpieces entering the drying zone 23 from all directions, quickly removing the special treatment agent liquid remaining on the surface of the workpieces, and promoting the curing of the conversion film. After the hot air is cooled down by heat exchange in the drying zone 23, it is collected by the first air outlet pipe group 52 and sent to the second air inlet pipe group 53 through the pipeline. The second air inlet pipe group 53 introduces the residual hot air into the transition zone 22, blowing air on the workpieces that have just been transferred from the spray zone 21, further accelerating the dripping of liquid from the surface of the workpieces. Finally, the hot air in the transition zone 22 is collected by the second air outlet pipe group 54 and sent back to the hot air supply unit 55 for reheating through the return air pipe, forming a closed-loop hot air system.

[0036] Specifically, multiple first air inlet duct groups 51 and first air outlet duct groups 52 are configured, and they are paired in a "one in, one out" manner: that is, one first air inlet duct group 51 corresponds to one first air outlet duct group 52 as a group, and multiple groups are arranged sequentially along the length of the drying zone 23. To avoid blind spots in the coverage of hot air in the drying zone 23, the first air inlet duct groups 51 of adjacent groups are distributed in an alternating manner (for example, the first group of first air inlet duct groups 51 is located on the left side wall of the drying zone 23, and the second group is located on the right side wall); at the same time, the first air outlet duct group 52 of the upstream group is connected to the first air inlet duct group 51 of the downstream group through a pipe, so that the hot air forms a continuous serpentine flow channel in the drying zone 23, improving the heat exchange efficiency between the hot air and the workpiece. In addition, the first air inlet duct group 51 and the first air outlet duct group 52 located at the beginning of the arrangement are deliberately set at the end of the drying zone 23 away from the transition zone 22; when the workpiece enters the drying zone 23 from the transition zone 22, it gradually completes the deep drying as the workpiece moves, ensuring that the workpiece is heated evenly as a whole.

[0037] Specifically, see Figure 9 The first air inlet pipe group 51 includes a number of ventilation pipes 511 arranged at intervals. Each ventilation pipe 511 has multiple air outlets 512 arranged at intervals along the vertical direction, and the air outlets 512 of two adjacent ventilation pipes 511 are staggered to achieve uniform air output.

[0038] The structures of the first air outlet duct group 52, the second air inlet duct group 53, and the second air outlet duct group 54 are similar to those of the first air inlet duct group 51. Their specific structures and working principles will not be described in detail here.

[0039] The hot air supply unit 55 mentioned above is existing technology. It typically includes heating components (such as electric heating elements), a circulating fan, and a filter component, and has the functions of generating, conveying, and purifying hot air. Its structure and working principle have been widely used in the field of industrial drying equipment and will not be described in detail here. Using this existing technology, the basic function of the hot air supply unit 55 is to introduce the generated hot air into the drying zone 23 through the first air inlet duct group 51, providing a stable heat source for the drying process. Simultaneously, the second air outlet duct group 54 returns the hot air that has undergone heat exchange in the transition zone 22 to this device, where it is reheated and then conveyed back to the first air inlet duct group 51, forming a closed-loop cycle.

[0040] Furthermore, the second air inlet duct group 53 is positioned close to the spray zone 21; the second air outlet duct group 54 is positioned close to the drying zone 23. From the perspective of moisture protection logic, the spray zone 21 will continuously generate moisture due to the spraying treatment of the workpiece. If the second air outlet duct group 54 is close to the spray zone 21, the moisture will easily be drawn into the second air outlet duct group 54 and enter the hot air supply unit 55 with the return air, which may cause the hot air supply unit 55 to become damp, reduce heating efficiency, and even affect the service life of the equipment. However, by positioning the second air inlet duct group 53 close to the spray zone 21, the residual heat from the drying zone 23 can be quickly applied to the workpiece that has just been transferred from the spray zone 21 to the transition zone 22, accelerating the dripping of residual liquid from the workpiece surface.

[0041] In a preferred embodiment, see [reference] Figure 2 The output end of the suspended conveyor 1 is equipped with a C-shaped frame 11, and the bottom of the C-shaped frame 11 is equipped with a hanging bracket 12 for suspending workpieces. Specifically, the suspended conveyor 1 also includes a conveying track 13 laid along the length of the pretreatment room 2, a roller assembly 14 adapted to the conveying track 13, and a transmission chain 15 that drives the roller assembly 14 to move. The conveying track 13 is installed on the outer side of the top of the pretreatment room 2, and the roller assembly 14 is fixed to the top of the C-shaped frame 11 through a connector. The whole structure belongs to the common suspended conveying structure in industrial conveying equipment, which can realize the continuous movement and conveying of workpieces along the spray zone 21, transition zone 22, and drying zone 23. The specific structure of the hanging bracket 12 should be adapted according to the structure of the workpiece, and the structure of the hanging bracket 12 is not limited here.

[0042] The pretreatment chamber 2 also includes two guide plates 26 that are inclined downward toward the two inner side walls respectively, and a first clearance groove 261 is formed between the two guide plates 26; the top of the pretreatment chamber 2 is provided with a second clearance groove 27 extending along its length direction; the first clearance groove 261 and the second clearance groove 27 are not on the same vertical plane, the bracket 12 can move along the first clearance groove 261, and the C-shaped frame 11 can move along the second clearance groove 27. The guide plate 26 is used to guide the special treatment agent liquid splashed during the spraying process to flow along its surface to the two inner sides of the pretreatment chamber 2, and finally flow down the inner wall of the pretreatment chamber 2 to the bottom collection tank 24; while the first clearance tank 261 and the second clearance tank 27 are not on the same vertical plane. On the one hand, because the C-shaped frame 11 has a "C" shaped structure, the staggered vertical plane position can ensure that the hanging frame 12 carrying the workpiece moves smoothly along the first clearance tank 261 and the C-shaped frame 11 is stably transported along the second clearance tank 27; on the other hand, the staggered vertical plane can form "vertical offset shielding"; which can prevent the treatment agent mixture from splashing outside the pretreatment chamber 2 through the first clearance tank 261 and the second clearance tank 27.

[0043] It is understood that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of this utility model, and all such substitutions or changes should fall within the protection scope of the appended claims of this utility model.

Claims

1. A zero-emission pretreatment device, characterized in that, include: A suspended conveyor (1) is used to convey workpieces along a designated path; The pretreatment room (2) is provided with a spray zone (21), a transition zone (22) and a drying zone (23) in sequence along the conveying direction of the workpiece; the bottom of the spray zone (21) and the transition zone (22) are respectively provided with a collection tank (24) with a funnel-shaped cross section, and the bottom of the collection tank (24) is provided with a drain pipe (241); the pretreatment room (2) is provided with a foot grid (25) located above the collection tank (24); Two spray devices (3) are symmetrically arranged on opposite inner walls of the spray area (21); each spray device (3) includes several first water supply pipes (31), several swing mechanisms (32) and several second water supply pipes (33), and each first water supply pipe (31) is provided with several first nozzles (311) facing the side wall of the workpiece; the output end of the swing mechanism (32) is connected to the second water supply pipe (33) to adjust the installation angle of the second water supply pipe (33), the second water supply pipe (33) is located above the foot tread grid (25), and its end is provided with a second nozzle (331) facing the bottom of the workpiece. A water circulation device (4) is provided, with its inlet end connected to a drain pipe (241) and its outlet end connected to the inlet end of each spray device (3); and A hot air circulation device (5) is located in the drying zone (23) and is used to spray hot air toward the workpiece.

2. The emission-free pretreatment device according to claim 1, characterized in that, The upper end of the first water supply pipe (31) is connected to a third water supply pipe (34) extending in an oblique upward direction, and the third water supply pipe (34) is provided with a plurality of third nozzles (341); the second water supply pipe (33) is a flexible hose, and one end of the second water supply pipe (33) is connected to the lower end of the first water supply pipe (31).

3. The emission-free pretreatment device according to claim 2, characterized in that, The first nozzles (311) on two adjacent first water supply pipes (31) are staggered; the third nozzles (341) on two adjacent third water supply pipes (34) are staggered.

4. The emission-free pretreatment device according to claim 1, characterized in that, The swing mechanism (32) includes a first hinge seat (321), a telescopic rod (322), a second hinge seat (323), and a support rod (324). The first hinge seat (321) and the second hinge seat (323) are both fixed in the spray area (21). The telescopic rod (322) includes a fixed rod (3221) and an extension rod (3222) that is slidably connected to the fixed rod (3221). One end of the fixed rod (3221) is hinged to the first hinge seat (321), and one end of the extension rod (3222) is connected to the end of the second water pipe (33). One end of the support rod (324) is hinged to the second hinge seat (323), and the other end is slidably connected to the fixed rod (3221).

5. The emission-free pretreatment device according to claim 4, characterized in that, The fixed rod (3221) is provided with first adjustment holes (3223) arranged at intervals along its length. A slide block (326) is slidably connected to the fixed rod (3221). The slide block (326) is detachably connected to any of the first adjustment holes (3223) on the fixed rod (3221) by a first screw (327). The slide block (326) is hinged to the end of the support rod (324).

6. The emission-free pretreatment device according to claim 4, characterized in that, It also includes an adjusting plate (325), on which an arc groove (3251) is provided; the end of the extension rod (3222) is provided with a short shaft (3226) and a second screw (3227), the adjusting plate (325) is rotatably connected to the short shaft (3226), and the second screw (3227) slides along the arc groove (3251); the end of the second water pipe (33) is fixed on the adjusting plate (325) by a pipe clamp.

7. The emission-free pretreatment device according to claim 1, characterized in that, The hot air circulation device (5) includes a first air inlet pipe group (51), a first air outlet pipe group (52), a second air inlet pipe group (53), a second air outlet pipe group (54), and a hot air supply unit (55). The air outlet end of the hot air supply unit (55) is connected to the first air inlet pipe group (51). The first air inlet pipe group (51) and the first air outlet pipe group (52) are respectively located on opposite inner sides of the drying zone (23). The first air outlet pipe group (52) is connected to the second air inlet pipe group (53) through a pipe. The second air inlet pipe group (53) and the second air outlet pipe group (54) are respectively located on opposite inner sides of the transition zone (22). The second air outlet pipe group (54) is connected to the return air end of the hot air supply unit (55).

8. The emission-free pretreatment device according to claim 7, characterized in that, The second air inlet duct group (53) is located near the spray area (21); the second air outlet duct group (54) is located near the drying area (23).

9. The emission-free pretreatment device according to claim 1, characterized in that, The output end of the suspended conveyor (1) is provided with a C-shaped frame (11), and the bottom of the C-shaped frame (11) is provided with a hanging bracket (12) for suspending workpieces; the pretreatment chamber (2) also includes two guide plates (26) that are inclined downward toward the two inner side walls respectively, and a first clearance groove (261) is formed between the two guide plates (26); the top of the pretreatment chamber (2) is provided with a second clearance groove (27) extending along its length direction; the first clearance groove (261) and the second clearance groove (27) are not on the same vertical plane, the hanging bracket (12) can move along the first clearance groove (261), and the C-shaped frame (11) can move along the second clearance groove (27).

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