Spraying device

Abstract

The invention relates to the technical field of casting spraying devices, in particular to a spraying device which comprises a device body, a nozzle and a sand core mould are mounted on the device body, the nozzle is located at the bottom of the sand core mould, and the device body comprises a mounting frame assembly, a coating pool, a flow guide structure, a stirring pool and a stirring assembly. The nozzle and the sand core mould are fixedly mounted on the mounting frame assembly, and the mounting frame assembly is detachably connected with the coating pool; the flow guide structure is arranged below the nozzle to guide materials; a plurality of stirring pools are distributed on the two opposite sides of the flow guide structure. According to the spraying device, the nozzle and the sand core mould are detachably connected with the coating pool through the mounting frame assembly, the flow guide structure and the coating pool are arranged in a high-low position mode, integrated space planning of spraying, flow guide, recycling and stirring is achieved, the problem that a traditional device is disordered in layout is solved, and the space utilization rate of the spraying device is increased.

Description

Technical Field

[0001] This application relates to the technical field of casting spraying apparatus, and more particularly to a spraying apparatus. Background Technology

[0002] In the foundry industry, to meet the process requirements of metal casting, refractory coatings are often applied to the surface of sand cores using a spraying device. For some special sand cores, such as turbine housing outer mold cores, only specific areas inside the cavity need to be sprayed, while the remaining areas do not require spraying.

[0003] When performing localized spraying, firstly, a sand core jig, nozzle, and baffle need to be set on the spraying device. The sand core jig should match the shape and size of the sand core to be sprayed and be positioned above the nozzle. The sand core jig is used to stably support and position the sand core, ensuring that the nozzle can accurately align with the area to be sprayed. The distance between the nozzle and the sand core needs to be adjusted according to the required coating thickness of the sprayed area to control the amount of coating adhering. The baffle is set around the nozzle circumference and its top is fitted and sealed to the sand core jig. It is used to physically isolate the sprayed area from the non-sprayed area to avoid coating splashing and contamination. When spraying different sand cores, the corresponding sand core jig, nozzle, and baffle should be replaced according to the specifications of the sand core. Secondly, in order to meet the coating performance, refractory coatings usually need to maintain a specific concentration and viscosity. However, during storage and use, the coating is prone to uneven composition due to particle sedimentation, which directly leads to inconsistent coating thickness on the surface of the sand core after spraying, affecting the protective effect of the coating. Therefore, the spraying device also needs a stirring device to ensure the uniformity of the coating through continuous stirring.

[0004] In summary, the layout design of a spraying device needs to comprehensively consider the installation positions of the sand core jig, nozzles, and the rationality of the mixing device arrangement. Given that sand cores are heavy metal components with diverse specifications, the layout must simultaneously ensure the installation stability of the sand core jig, nozzles, and baffles to meet the spraying accuracy requirements. However, current spraying devices on the market generally suffer from unreasonable spatial layouts, reducing the efficiency and accuracy of sand core spraying.

[0005] Therefore, a spraying device is needed to solve the problem that the existing coating equipment has an unreasonable spatial layout, which reduces the efficiency and accuracy of sand core spraying. Summary of the Invention

[0006] In order to achieve a reasonable arrangement of the installation positions of the sand core jig, nozzle, and mixing device, and to improve the efficiency and accuracy of sand core spraying, this application provides a spraying device.

[0007] This application provides a spraying device, which adopts the following technical solution: A spraying device includes a device body, on which a nozzle and a sand core fixture are mounted. The nozzle is located at the bottom of the sand core fixture. The device body includes a mounting frame assembly, a paint tank, a flow guiding structure, a mixing tank, and a mixing assembly. The nozzle and the sand core fixture are fixedly mounted on the mounting frame assembly, and the mounting frame assembly is detachably connected to the paint tank. The flow guiding structure is disposed below the nozzle to guide the material. Multiple mixing tanks are provided and distributed on opposite sides of the flow guiding structure. The height of each mixing tank is lower than the height of the flow guiding structure to recover excess material. The nozzle is connected to all the mixing tanks. The mixing assembly oscillates along the bottom of the mixing tank to agitate the material in the mixing tank.

[0008] By adopting the above technical solution, the nozzle is located at the bottom of the sand core fixture, allowing for precise spraying onto the sand core. The mounting frame assembly is detachably connected to the paint tank, facilitating disassembly and replacement, enabling rapid replacement of the sand core fixture and nozzle. The flow guiding structure below the nozzle directs excess paint to the mixing tanks on both sides, achieving material recovery. Simultaneously, the mixing component oscillates along the bottom of the mixing tank, agitating the material and preventing material sedimentation that could lead to uneven concentration. Compared to existing technologies, the detachable connection of the nozzle, sand core fixture, and paint tank via the mounting frame assembly, along with the high-low arrangement of the flow guiding structure and paint tank, achieves integrated spatial planning for "spraying-flow guiding-recovery-mixing," solving the problem of chaotic layout in traditional devices and improving the space utilization rate of the spraying equipment.

[0009] Optionally, the flow guiding structure includes a flow guiding cover plate, which includes a flow guiding part for guiding the material into the mixing tanks on both sides.

[0010] By adopting the above technical solution, the guide cover plate guides the excess coating of the sprayed sand core through the flow guide section to the mixing tanks on both sides, effectively guiding the excess material into the mixing tank for recycling, and further optimizing the layout rationality of the "flow guide-recycling" link.

[0011] Optionally, the flow guide cover further includes a support portion, which is integrally formed with the flow guide portion, and the support portion is used to reinforce and support the mounting bracket assembly.

[0012] By adopting the above technical solution, the support part and the flow guiding part of the guide cover are integrally formed, which provides support for the mounting frame assembly while guiding the material. There is no need to add an additional support structure for the mounting frame assembly, thus improving the overall space utilization of the spraying device.

[0013] Optionally, the mounting bracket assembly includes a mounting plate and a mounting bracket. The mounting plate is used to fix the nozzle and sand core fixture. The mounting plate is fixedly mounted on the mounting bracket, and the mounting bracket is fixedly connected to and detachably mounted on the paint tank.

[0014] By adopting the above technical solution, the nozzle and sand core fixture are fixedly installed on the mounting plate, the mounting plate is fixedly installed on the mounting bracket, and the mounting bracket is detachably installed on the paint tank, forming a modular installation structure. This makes the installation position of the nozzle and sand core fixture relatively fixed and detachable from the paint tank, which not only ensures the accurate installation layout of the nozzle and sand core fixture, but also facilitates the direct disassembly and replacement of the mounting bracket according to the sand core specifications, thereby improving the layout flexibility and changeover efficiency of the spraying device.

[0015] Optionally, the stirring assembly includes a stirring element and a stirring drive element. The stirring element is rotatably mounted on the device body, and the stirring drive element drives the stirring element to reciprocate in an arc shape at the bottom of the stirring tank.

[0016] By adopting the above technical solution, the stirring drive drives the stirring component to reciprocate in an arc shape at the bottom of the mixing tank, stirring the material in the mixing tank and making the material evenly mixed. There is no need to reserve a large amount of stirring space above the mixing tank, thus balancing the stirring effect and space adaptability.

[0017] Optionally, the bottom surface of the mixing tank is an arc-shaped surface, and the curvature of the arc-shaped surface is consistent with the swing curvature of the agitator. The agitator is used to push the material at the lower part of the arc-shaped surface to the higher part.

[0018] By adopting the above technical solution, the bottom surface of the mixing tank is provided with an arc-shaped surface, the curvature of which is consistent with the swing curvature of the agitator. When the agitator swings, it can push the material at the lower part of the arc-shaped surface to the higher part, so that the agitator can realize the high and low position flipping of the material in the limited mixing tank, and at the same time improve the uniformity of material mixing.

[0019] Optionally, the device body is fixedly equipped with a circulation component for uniformly distributing material. The circulation component includes a return pipe, a circulation pipe, and a circulation drive structure. One end of the return pipe is connected to the mixing tank; one end of the circulation pipe is connected to the mixing tank; one end of the circulation drive structure is connected to the return pipe, and the other end is connected to the circulation pipe. The circulation drive structure is used to transport the material in the return pipe into the circulation pipe.

[0020] By adopting the above technical solution, the return pipe takes material from the mixing tank, transports it to the circulation pipe through the circulation drive structure, and then sends the material back to the mixing tank through the circulation pipe, forming a paint circulation. This adapts to the overall integrated layout of the spraying device. At the same time, the circulation can even out the paint concentration and work with the mixing components to improve the paint quality, achieving dual optimization of function and layout.

[0021] Optionally, the outlet of the circulation pipe is located at the lowest point of the arc-shaped surface, and the circulation drive structure drives the material in the circulation pipe to move the material at the lowest point of the arc-shaped surface to the highest point of the arc-shaped surface.

[0022] By adopting the above technical solution, the circulating coating can be precisely applied to materials that are prone to sedimentation at low levels. Based on the existing arc-shaped layout of the mixing tank, it enhances the material circulation and agitation effect, which helps to further homogenize the material concentration in the mixing tank and improve the uniformity of material distribution.

[0023] In summary, this application includes at least one of the following beneficial technical effects: 1. The nozzle, sand core fixture, and paint tank are detachably connected via the mounting bracket assembly. The flow guiding structure and the high and low position layout of the paint tank realize the integrated spatial planning of "spraying-flow guiding-recycling-mixing", which solves the problem of chaotic layout of traditional equipment and improves the space utilization of the spraying equipment. 2. The guide cover guides the excess coating of the sprayed sand core through the flow guide to the mixing tanks on both sides, effectively guiding the excess material into the mixing tank for recycling, and further optimizing the layout rationality of the "flow guide-recycling" link; 3. The return pipe takes material from the mixing tank, conveys it to the circulation pipe through the circulation drive structure, and then sends the material back to the mixing tank through the circulation pipe, forming a paint circulation. This adapts to the overall integrated layout of the spraying device. At the same time, the circulation can even out the paint concentration and work with the mixing components to improve the paint quality, achieving dual optimization of function and layout. Attached Figure Description

[0024] Figure 1 This is a structural schematic diagram of an embodiment of the present application, used to illustrate the overall structure of the device body; Figure 2 This is a partial structural diagram of an embodiment of this application. Figure 1 Used to demonstrate the structure of the mounting bracket assembly; Figure 3 This is a partial structural diagram of an embodiment of this application. Figure 2 This is used to show the location of the flow distribution interface and the first spraying interface; Figure 4 This is a cross-sectional view of an embodiment of this application, used to show the location of the arc-shaped surface and the circulation pipe; Figure 5 for Figure 4 An enlarged schematic diagram of section A shows the placement of the positioning protrusions, positioning grooves, and flow guide cover. Figure 6 This is a partial structural diagram of an embodiment of this application. Figure 3 This is used to demonstrate the specific structure of the loop group.

[0025] Reference numerals: 1. Device body; 111. Paint tank; 121. Nozzle; 131. Sand core jig; 2. Mounting frame assembly; 211. Mounting plate; 212. Support column; 213. Spraying pipe; 214. Through hole; 221. Mounting bracket; 222. Hook; 223. Diverter pipe; 2231. Positioning protrusion; 224. Diverter interface; 225. Spraying interface one; 226. C-shaped connector; 3. Flow guiding structure; 311. Flow guiding cover; 312. Drainage part; 313. Support 3131, Positioning Groove; 321, Flow Guide Support Plate; 4, Mixing Tank; 411, Arc-shaped Surface; 5, Mixing Assembly; 511, Mixing Drive Component; 512, Mixing Component; 6, Circulation Assembly; 611, Return Pipe; 621, Circulation Pipe; 6211, Liquid Outlet; 631, Circulation Drive Structure; 632, Diaphragm Pump; 6321, Return Interface; 6322, Connecting Pipe; 6323, Circulation Interface; 6324, Spraying Interface Two; 633, Pneumatic Drive Structure; 7, Salvage Net. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0027] Example: A spraying device, reference Figure 1 and Figure 2 Including the device body 1, and then combined Figure 4The device body 1 is equipped with a paint tank 111, a nozzle 121, a sand core fixture 131, a baffle 141, a mounting frame assembly 2, a flow guiding structure 3, a mixing tank 4, and a mixing assembly 5. The nozzle 121 and the sand core fixture 131 are located at the opening of the paint tank 111. The workpiece is placed on the sand core fixture 131, which has an opening that exposes the area of ​​the workpiece to be sprayed. The nozzle 121 is located at the bottom of the sand core fixture 131, and sprays the material from the paint tank 111 onto the area of ​​the workpiece to be sprayed. The baffle 141 is arranged circumferentially around the nozzle 121, and its top end is fitted and sealed to the sand core fixture 131, physically separating the sprayed area from the non-sprayed area. The nozzle 121 and the baffle 141... The sand core fixture 131 is fixedly installed on the mounting frame assembly 2, and the mounting frame assembly 2 is detachably connected to the opposite sides of the paint tank 111; the flow guiding structure 3 is set below the nozzle 121, and multiple mixing tanks 4 are provided and distributed on the opposite sides of the flow guiding structure 3. The setting height of each mixing tank 4 is lower than the setting height of the flow guiding structure 3. During the spraying process of the workpiece, the excess material enters the mixing tank 4 under the guidance of the flow guiding structure 3 to realize material return. The nozzle 121 is connected to all the mixing tanks 4, and the nozzle 121 can reuse the recovered material for spraying the workpiece; the stirring assembly 5 is fixedly installed on the side wall of the mixing tank 4. The stirring assembly 5 can swing and stir the material along the bottom of the mixing tank 4 to prevent material sedimentation and uneven concentration.

[0028] refer to Figure 2 and Figure 3 The mounting bracket assembly 2 includes a mounting plate 211 and a mounting bracket 221. One end of the mounting plate 211 is fixedly connected to the nozzle 121 and the sand core fixture 131, and the other end is fixedly connected to the mounting bracket 221. A support column 212 is fixedly installed on the end of the mounting plate 211 facing the sand core fixture 131. The support columns 212 are distributed at the corners of the mounting plate 211. The sand core fixture 131 is fixedly installed on the support column 212 by bolts. With the support of the support column 212, a space for accommodating the nozzle 121 is formed between the sand core fixture 131 and the mounting plate 211, which improves the rationality of the overall layout of the coating device.

[0029] refer to Figure 2 and Figure 3 A spray pipe 213 is fixedly installed on the mounting plate 211, and the spray pipe 213 passes through the upper and lower sides of the mounting plate 211. The nozzle 121 is located at one end of the spray pipe 213 near the sand core fixture 131. The mounting plate 211 has multiple through holes 214, which are then combined with... Figure 4During the spraying process, excess material flows down through the through hole 214 onto the guide structure 3. The mounting bracket 221 is a frame structure composed of multiple horizontal and vertical beams, which facilitates the flow of material on the mounting plate 211 from the hollowed-out portion into the mixing tank 4. The hollowed-out design also facilitates the passage of the spray pipe 213 through the mounting bracket 221. At the same time, the stress on the frame structure can be distributed through the nodes of the horizontal and vertical beams, ensuring the overall structural strength of the mounting bracket 221. Hooks 222 are integrally formed on opposite sides of the mounting bracket 221. The mounting bracket 221 can be directly hung on the two sides of the paint tank 111 through the hooks 222, realizing the rapid assembly of the mounting bracket 221 and the paint tank 111. This allows the sand core jig 131, nozzle 121, spray pipe 213, mounting plate 211, and mounting bracket 221 to form a modular installation structure, further improving the layout rationality of the spraying device.

[0030] refer to Figure 3 and Figure 4 A diversion pipe 223 is fixedly installed at the bottom of the mounting bracket 221. The diversion pipe 223 is provided with a diversion interface 224 and a spraying interface 225. The diversion interface 224 is connected to the end of the spraying pipe 213 away from the sand core fixture 131 through a hose structure. The spraying interface 225 is connected to the inside of the mixing tank 4 through a hose structure. A C-shaped connector 226 is fixedly installed at the bottom of the mounting bracket 221. The mounting bracket 221 is fixedly connected to the diversion pipe 223 through the C-shaped connector 226 to ensure the connection strength between the mounting bracket 221 and the diversion pipe 223.

[0031] refer to Figure 4 and Figure 5 The flow guiding structure 3 includes a flow guiding cover plate 311 and a flow guiding support plate 321. The flow guiding cover plate 311 includes a flow-inducing part 312 and a support part 313. The flow-inducing part 312 and the support part 313 are integrally formed. The flow-inducing part 312 is located on both sides of the support part 313 and is inclined to facilitate the flow of materials into the mixing tanks 4 on both sides. The support part 313 is a planar structure and is located in the middle of the diversion pipe 223. It is used to abut against and support the diversion pipe 223, thereby achieving overall support for the mounting frame assembly 2. The bottom of the diversion pipe 223 is integrally formed with a positioning protrusion 2231, and the support part 313 is provided with a positioning protrusion. The positioning groove 3131 with a concave-convex fit is provided. The extension direction of the positioning protrusion 2231 is perpendicular to the length direction of the diversion pipe 223. During the process of hanging the mounting bracket 221 on both sides of the paint tank 111, the positioning protrusion 2231 and the positioning groove 3131 can be matched to prevent the mounting bracket 221 from moving along the length direction of both sides of the paint tank 111, thus ensuring the accurate installation of the mounting bracket 221. The flow guide support plate 321 is located at the bottom of the flow guide cover plate 311 and is fixedly connected to the flow guide parts 312 on both sides to support the flow guide cover plate 311.

[0032] refer to Figure 1 and Figure 4 The stirring assembly 5 includes a stirring drive 511 and a stirring element 512. In this embodiment, the stirring drive 511 includes a swing cylinder. The stirring drive 511 is fixedly installed on the top of the stirring tank 4. The stirring element 512 is rotatably installed on the edge of the stirring tank 4 through a bearing. The output shaft of the stirring drive 511 is fixed to one end of the stirring element 512. The stirring drive 511 drives the stirring element 512 to swing, so that the end of the stirring element 512 that extends into the stirring tank 4 swings back and forth in an arc at the bottom of the stirring tank 4, thereby achieving uniform concentration of materials in the stirring tank 4.

[0033] refer to Figure 1 and Figure 4 The bottom surface of the mixing tank 4 is an arc-shaped surface 411. The curvature of the arc-shaped surface 411 is consistent with the swing curvature of the agitator 512. Driven by the agitator 511, the end of the agitator 512 pushes the material at the lower part of the arc-shaped surface 411 to the upper part. The agitator end of the agitator 512 is provided with a clearance groove. As the agitator 512 swings in an arc shape, the material turning and mixing effect is enhanced. A retrieval net 7 is also installed in the mixing tank 4 to retrieve workpieces that have fallen into the mixing tank 4.

[0034] refer to Figure 4 and Figure 6 The device body 1 is fixedly equipped with a circulation component 6, which includes a return pipe 611, a circulation pipe 621, and a circulation drive structure 631. In this embodiment, the circulation drive structure 631 includes a diaphragm pump 632 and a pneumatic drive structure 633 connected to the diaphragm pump 632. One end of the return pipe 611 is connected to the mixing tank 4, and one end of the circulation pipe 621 is connected to the mixing tank 4. One end of the diaphragm pump 632 is connected to the return pipe 611, and the other end is connected to the circulation pipe 621. The circulation drive structure 631 is used to transport the material in the return pipe 611 to the circulation pipe 621.

[0035] refer to Figure 4 and Figure 6 The diaphragm pump 632 has a return port 6321 on one side and a connecting pipe 6322 on the opposite side. The connecting pipe 6322 has a non-connected circulation port 6323 and a second spraying port 6324. The return port 6321 connects to the return pipe 611, the circulation port 6323 connects to the circulation pipe 621, and the second spraying port 6324 connects to the diversion pipe 223. There are two specific paths and processes for the two working modes. In the spraying mode, the circulation port 6323 is closed. The material in the mixing tank 4 first flows into the diaphragm pump 632 through the return pipe 611. Under the action of the circulation drive structure 631, the material is output from the second spraying port 6324 of the connecting pipe 6322, and then... Figure 2 , Figure 3 The material then enters the diversion pipe 223 and the spray pipe 213 sequentially through the hose structure, and is finally sprayed onto the workpiece area to be coated by the nozzle 121, realizing the reuse of the material for coating. Material circulation mode: At this time, the second spray interface 6324 is closed, and the material in the mixing tank 4 still enters the diaphragm pump 632 through the return pipe 611. Then the material is output from the circulation interface 6323 of the connecting pipe 6322 and flows into the circulation pipe 621 through the hose structure. The outlet of the circulation pipe 621 is located at the lowest point of the arc surface 411 of the mixing tank 4. Under the drive of the circulation drive structure 631, the material is sprayed out from the outlet of the circulation pipe 621, pushing the material at the lowest point of the arc surface 411 to a higher point, further enhancing the material mixing effect. At the same time, some of the clearance grooves on the agitator 512 can avoid the liquid outlet 6211 of the circulation pipe 621, avoiding structural interference and further optimizing the rationality of the spatial layout of the device.

[0036] The implementation principle of this application embodiment is as follows: the workpiece is placed on the sand core fixture 131, and the nozzle 121 sprays the material recovered in the mixing tank 4 onto the workpiece to be sprayed through the spray pipe 213 and the diversion pipe 223; during spraying, excess material flows to the guide structure 3 through the through hole 214 on the mounting plate 211, and is guided into the mixing tanks 4 on both sides by the inclined guide part 312 to achieve backflow. The stirring component 5 swings back and forth along the arc surface 411 of the mixing tank 4 to prevent material deposition; the circulation component 6 can switch working modes: during spraying, the circulation drive structure 631 transports the material in the mixing tank 4 to the nozzle 121 for reuse through the return pipe 611, the second spraying interface 6324, and the diversion pipe 223; during circulation, the material is sent back to the mixing tank 4 through the circulation interface 6323 and the circulation pipe 621. The combination of the arc surface 411 and the stirring component 512 enhances the mixing effect.

[0037] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A spraying apparatus, comprising an apparatus body (1), wherein the apparatus body (1) is equipped with a nozzle (121) and a sand core fixture (131), the nozzle (121) being located at the bottom of the sand core fixture (131), characterized in that: The device body (1) includes a mounting frame assembly (2), a paint tank (111), a flow guiding structure (3), a mixing tank (4), and a mixing assembly (5). The nozzle (121) and the sand core fixture (131) are fixedly installed on the mounting frame assembly (2). The mounting frame assembly (2) is detachably connected to the paint tank (111). The flow guiding structure (3) is located below the nozzle (121) to guide the material. Multiple mixing tanks (4) are provided and distributed on opposite sides of the flow guiding structure (3). The height of each mixing tank (4) is lower than the height of the flow guiding structure (3) to recover excess material. The nozzle (121) is connected to all the mixing tanks (4). The mixing assembly (5) swings along the bottom of the mixing tank (4) to stir the material in the mixing tank (4).

2. The spraying device according to claim 1, characterized in that: The flow guiding structure (3) includes a flow guiding cover plate (311), which includes a flow guiding part (312) for guiding the material into the mixing tanks (4) on both sides.

3. The spraying device according to claim 2, characterized in that: The flow guide cover (311) also includes a support (313), which is integrally formed with the flow guide (312) and is used to reinforce the support of the mounting bracket assembly (2).

4. The spraying device according to claim 1, characterized in that: The mounting bracket assembly (2) includes a mounting plate (211) and a mounting bracket (221). The mounting plate (211) is used to fix the nozzle (121) and the sand core fixture (131). The mounting plate (211) is fixedly mounted on the mounting bracket (221). The mounting bracket (221) is fixedly connected to and detachably mounted on the paint tank (111).

5. A spraying device according to claim 1, characterized in that: The stirring assembly (5) includes a stirring element (512) and a stirring drive element (511). The stirring element (512) is rotatably mounted on the device body (1), and the stirring drive element (511) drives the stirring element (512) to reciprocate in an arc shape at the bottom of the stirring tank (4).

6. A spraying apparatus according to claim 5, characterized in that: The bottom surface of the mixing tank (4) is an arc-shaped surface (411), and the curvature of the arc-shaped surface (411) is consistent with the swing curvature of the stirring component (512). The stirring component (512) is used to push the material at the lower part of the arc-shaped surface (411) to the higher part.

7. A spraying apparatus according to claim 6, characterized in that: The device body (1) is fixedly equipped with a circulation component (6) for uniform material concentration. The circulation component (6) includes a return pipe (611), a circulation pipe (621), and a circulation drive structure (631). The feed end of the return pipe (611) is connected to the stirring tank (4); the discharge end of the circulation pipe (621) is connected to the stirring tank (4); one end of the circulation drive structure (631) is connected to the return pipe (611), and the other end is connected to the circulation pipe (621). The circulation drive structure (631) is used to transport the material in the return pipe (611) to the circulation pipe (621).

8. A spraying apparatus according to claim 7, characterized in that: The outlet of the circulation pipe (621) is located at the lowest point of the arc surface (411). The circulation drive structure (631) drives the material in the circulation pipe (621) to push the material at the lowest point of the arc surface (411) to the highest point of the arc surface (411).

Images