Anti-liquid level fluctuation structure in chain cleaning equipment used in solar cell production

Abstract

This utility model relates to a liquid level fluctuation prevention structure in a chain cleaning device used in solar cell production. The chain cleaning device includes an acid washing tank II and an alkaline washing tank II. Multiple rollers are arranged at the liquid surface of the acid washing tank / alkaline washing tank, with the lower part of the rollers immersed in the liquid. Multiple partition chambers are spaced apart within the acid washing tank II / alkaline washing tank II, with the upper end of each partition chamber higher than the liquid surface. The upper end of each partition chamber is open, and the upper cavity of each partition chamber is further divided into multiple smaller cavities, which are connected to the acid washing tank II / alkaline washing tank II via the lower part of the partition chamber. Liquid level fluctuations caused by roller rotation are partially offset by the partition chambers. Small liquid droplets splashed during roller rotation fall into the smaller cavities and eventually flow back into the acid washing tank II / alkaline washing tank II. The beneficial effect achieved by this utility model is that it improves the uniformity of etching each solar panel while ensuring efficiency.

Description

Technical Field

[0001] This utility model relates to the field of solar panel manufacturing technology, and in particular to a structure for preventing liquid level fluctuations in a chain cleaning device used in solar cell production. Background Technology

[0002] During the manufacturing process of solar panels, the surface of the panels is etched by acid / alkali. For example, the process may involve spraying a protective film onto the surface of the panel, followed by acid washing, water washing, and drying (or other process steps).

[0003] In equipment for acid washing / water washing: a. It is usually implemented using a long tank body with multiple rollers mounted on it (these rollers are driven by chains, hence the entire cleaning equipment is also called a chain cleaning machine); b. In addition, the long tank body is divided into multiple smaller long tank units by multiple partitions, each containing acid or water (called acid washing tanks / water washing tanks); c. During operation, the solar panels are placed on the rollers and passed through different washing tanks. The surface of the rollers has a nap, and its lower cylindrical surface can contact the liquid in the corresponding washing tank. As the rollers rotate, a certain amount of liquid adheres to the nap and comes into contact with the lower surface of the solar panels, thereby completing the etching / cleaning process.

[0004] During pickling, the rotation of the rollers and the contact between the fluff and the lower surface of the solar panel cause fluctuations in the liquid surface (large fluctuations can lead to over-etching). Furthermore, the rotation of the rollers causes some liquid to splash onto the surface, further exacerbating the fluctuations. These fluctuations result in varying liquid levels, leading to different amounts of acid / alkali adhering to the rollers, resulting in inconsistent etching of the bottom surface of the solar panel and ultimately affecting the manufacturing quality.

[0005] Based on this, our company has designed some structures to reduce liquid level fluctuations in the pickling / alkali washing tanks. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a structure to prevent liquid level fluctuations in a chain cleaning device for solar cell production.

[0007] The purpose of this utility model is achieved through the following technical solution: a liquid level fluctuation prevention structure in a chain cleaning equipment for solar cell production, the chain cleaning equipment including an acid washing tank II / alkali washing tank II, and multiple rollers are arranged at the liquid level of the acid washing tank / alkali washing tank, with the lower part of the rollers immersed in the liquid level.

[0008] The pickling tank II / alkali washing tank II is provided with multiple partition chambers spaced apart, and the upper end of the partition chamber is higher than the liquid level in the pickling tank II / alkali washing tank II.

[0009] The upper end of the partition cavity is open, and the upper cavity of the partition cavity is further divided into multiple small cavities, which are connected to the pickling tank II / alkali washing tank II via the lower part of the partition cavity.

[0010] The fluctuations in the liquid level caused by the rotation of the roller are partially offset by the partition cavity components;

[0011] When the rollers rotate, the splashed droplets fall into the small cavity and eventually flow back into the pickling tank II / alkali washing tank II.

[0012] As a preferred technical solution, the lower part of the partition cavity component has an auxiliary through hole running through it from left to right; in the acid washing tank II / alkali washing tank II, the liquid in the upper part is separated by the partition cavity component, and the liquid in the lower part flows through the auxiliary through hole.

[0013] As a preferred technical solution, the partition cavity includes an upper cavity and a lower cavity that are interconnected; the upper cavity is divided into multiple smaller cavities, and the lower cavity has auxiliary through holes running horizontally through its walls. When the roller rotates, small droplets splashed by the roller fall into the smaller cavities and then flow back into the pickling tank II / alkali washing tank II through the auxiliary through holes.

[0014] As a preferred technical solution, the partition cavity component is a rectangular cavity formed by splicing a left plate, a right plate, a front plate, a rear plate, and a bottom plate, with the top of the rectangular cavity open. A horizontal plate is provided at the upper part of the partition cavity component, dividing the interior of the partition cavity component into an upper cavity and a lower cavity. Multiple through holes are opened in the horizontal plate along the vertical direction. The upper cavity is divided into multiple smaller cavities by multiple vertical plates spaced at intervals, forming a structure where the liquid levels in the smaller cavities do not interfere with each other. Multiple auxiliary through holes are opened on the left and right side walls of the lower cavity.

[0015] As a preferred technical solution, each of the acid washing tank II / alkali washing tank II is provided with a partition cavity on the side of each roller that can lift splashing droplets.

[0016] As a preferred technical solution, the top of the partition cavity is 0.-cm higher than the liquid level in the acid washing tank II / alkali washing tank II.

[0017] As a preferred technical solution, the roller is provided with an arc-shaped mesh below the liquid surface; the arc-shaped mesh and the roller are on the same axis, and there is a gap between them with a gap size of -cm, which can prevent the water from fluctuating in the vertical direction to a certain extent.

[0018] To facilitate understanding, the working process and working principle of this solution will be explained.

[0019] ① It should be noted that in the acid or alkali washing tank of the chain cleaning equipment, the lower part of the corresponding roller is in contact with the liquid surface in the tank, and there is a solar panel above the roller. When the roller rotates, acid / alkali will adhere to the cylindrical surface of the roller. Therefore, as the roller rotates, the solar panel can be conveyed forward on the one hand, and the bottom surface of the solar panel is in contact with the cylindrical surface of the roller. Thus, the bottom surface of the solar panel is in contact with the acid on the cylindrical surface, thereby achieving etching. ②However, a. because the rollers rotate and are in contact with the liquid surface, their rotation pushes the liquid surface, causing it to bounce back when it hits the inner wall of the pool, resulting in surface undulation; b. this undulation causes uneven immersion of the rollers (e.g., shallower immersion at the trough and deeper immersion at the crest), leading to inconsistent amounts of acid / alkali adhering to the roller surface. This results in uneven etching between different solar panels (e.g., less acid adhering at the trough). When in contact with the corresponding solar panel, the etching is small); c. Especially in the pickling / alkali washing tank, there are multiple rollers. When multiple rollers push the corresponding liquid surface to fluctuate, the fluctuation of the entire liquid surface will be very complex (not easy to control). Therefore, it is impossible to adjust and control the fluctuation by adjusting the speed of the rollers; ③ In addition, when the rollers are rotating, they will carry up some liquid (carry up a clump of liquid that leaves the liquid surface and is also accompanied by small liquid droplets splashing). These clumps and small liquid droplets will fall back to the liquid surface, which will further aggravate the complexity of the liquid surface fluctuation and make it impossible to control the liquid surface fluctuation well.

[0020] Currently, to address the issue of inconsistent etching levels in solar panels caused by liquid surface fluctuations, most solar panel manufacturers reduce the rotational speed of the rollers in the acid / alkali washing tanks. Lower roller speeds result in less liquid surface fluctuation (and a smaller amount of liquid clumps and droplets). However, regardless of the roller speed, liquid surface fluctuations cannot be completely eliminated; furthermore, reducing roller speed also impacts production efficiency.

[0021] Based on this, the proposed solution has the following design:

[0022] ① In the pickling tank, partition chambers are set on both sides of each roller (the top of the partition chamber extends out of the liquid surface). When the roller pushes the liquid surface to fluctuate, the fluctuating liquid surface returns when it encounters the wall of the partition chamber (equivalent to a single roller causing the liquid surface fluctuation in this area). Compared with multiple rollers pushing the liquid surface to fluctuate (the liquid surfaces pushed by these rollers will affect each other), this design reduces the complexity of the fluctuation (a single fluctuation can be well controlled by adjusting the speed of the roller. For example, this design will also produce certain peaks and troughs, but since the fluctuation is single, it is only necessary to control the amount of acid / alkali solution adhering to the roller per unit time to be consistent).

[0023] ②a. In addition, the partition chamber is a rectangular cavity with an open top, including an upper cavity and a lower cavity (the two are connected). The upper cavity is divided into multiple small cavities by a vertical plate, and an auxiliary through hole is opened at the lower part of the lower cavity; b. When the roller rotates, it carries liquid clumps and small droplets away from the liquid surface. Under the action of inertia and gravity, these liquid clumps and small droplets fall into the small cavities. Therefore, the falling of these liquid clumps and small droplets will not have a significant impact on the liquid surface fluctuation at the roller. The fallen liquid clumps and small droplets flow back into the pickling tank / alkali washing tank through the small cavity, the lower cavity, and the auxiliary through hole; c. In addition, the setting of multiple small cavities also has a corresponding function: allowing liquid clumps and small droplets to fall into the small cavities. Compared with not setting small cavities, the fluctuation of the liquid surface in the upper cavity is smaller (although the liquid clumps and small droplets do not fall directly onto the liquid surface at the roller, the upper cavity is connected to the liquid in the pickling tank, making it difficult to...). To avoid fluctuations, the small cavity design minimizes the mutual interference caused by liquid clumps and droplets falling into the upper cavity – essentially separating these interferences. For example, if a liquid clump falls into cavity A and a droplet falls into cavity B, the fluctuations in cavity A and between cavity B have minimal mutual influence. d. When liquid clumps or droplets fall into the small cavity, the liquid level in the small cavity will be slightly higher than in other pickling tanks. At this time, the corresponding volume of liquid in the lower cavity will flow into the pickling tank through auxiliary holes. This liquid flows from top to bottom in the pickling tank and replenishes the roller position. Although it will also cause liquid level fluctuations, the impact of these fluctuations is minimal and almost negligible (for example, if a large U-shaped tube is filled with water and a stone is thrown into one end, the liquid level at the other end will rise, but the fluctuation at the other end will be very small).

[0024] ③ In this scheme, in order to further reduce the fluctuation of the liquid surface, arc-shaped meshes are also set at intervals below the roller (when the liquid surface fluctuates up and down, it will be blocked to a certain extent by the arc-shaped meshes, thereby reducing the fluctuation).

[0025] This utility model has the following advantages:

[0026] While ensuring efficiency, the uniformity of etching on each solar panel was improved, thus enabling good quality control.

[0027] Specifically, this solution, through the design of the partitioned cavity and the arc-shaped mesh, enables good control of liquid surface fluctuations even at high roller speeds (the influencing factors of fluctuations are relatively simple, and the fluctuations are subject to little interference, making control relatively easy – this can be achieved by fine-tuning the roller speed). Higher roller speeds improve etching efficiency (of course, the amount of acid / alkali solution adhering to the roller also needs to be increased), while more uniform fluctuations allow the amount of acid / alkali solution adhering to the roller per unit time to remain relatively stable, thereby ensuring the uniformity of etching for each solar panel. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a chain cleaning equipment containing pickling tank II / alkali washing tank II.

[0029] Figure 2 This is a schematic diagram of the structure of this utility model;

[0030] Figure 3 for Figure 2 Enlarged view of AA;

[0031] Figure 4 A schematic diagram showing the structure of an arc-shaped mesh at the bottom of the roller and a partition cavity on the side of the roller that lifts up the liquid droplets;

[0032] Figure 5 This is a structural diagram of the upper part of the partition cavity component;

[0033] In the figure: 10-roller, 20-partitioned cavity, 21-small cavity, 22-auxiliary through hole, 23-horizontal plate, 2301-through hole, 24-vertical plate, 30-arc mesh. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0035] It should be noted that the orientation or positional relationship indicated by terms such as "left" and "right" is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this utility model is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art. Such terms 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 be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] In existing related technologies, such as Figure 1As shown, a chain cleaning device for manufacturing solar panels typically includes a protective liquid spray tank I, an acid / alkali washing tank II, and a water washing tank III connected in sequence. Each tank is equipped with corresponding rollers, and the solar panel is placed on the rollers. As the rollers rotate, the solar panel is positioned in different tank locations. When the solar panel moves to the protective liquid spray tank I, a protective liquid is sprayed onto its surface (to prevent subsequent acid / alkali splashes onto the panel surface). When it moves to the acid / alkali washing tank II, the lower part of the corresponding roller is immersed in the acid or alkali solution (the roller has lint). As the roller rotates, some acid / alkali adheres to it—thus, when the bottom surface of the solar panel contacts the corresponding roller, the acid / alkali will etch the bottom surface of the solar panel.

[0037] However, in the acid washing tank II / alkali washing tank II, because the rollers are in contact with the liquid surface in the tank, the rotation of the rollers pushes the liquid surface (horizontally), causing fluctuations in the liquid surface, which in turn causes some liquid splashing (the splashing liquid further exacerbates the fluctuations). If the liquid surface fluctuates, the degree to which the rollers are immersed in the liquid surface will be uneven, resulting in different amounts of acid / alkali liquid adhering to the rollers. This leads to different degrees of etching on the lower surface of the solar panel, thus affecting the etching effect of the solar panel.

[0038] Therefore, this solution offers the following approach: by reducing the volume, the fluctuation of the liquid surface can be reduced, thereby ensuring that the etching degree of the lower surface of each solar panel remains relatively consistent.

[0039] The concept of the solution will be further illustrated below through specific embodiments. It should be noted that, unless otherwise specified, the embodiments, features, and technical solutions within these embodiments can be combined with each other.

[0040] like Figure 2 and Figure 3 As shown, this embodiment provides a liquid level fluctuation prevention structure in a chain cleaning equipment for solar cell production. The chain cleaning equipment includes an acid washing tank II / alkali washing tank II, and multiple rollers 10 are provided at the liquid level of the acid washing tank / alkali washing tank, with the lower part of the rollers 10 immersed in the liquid level.

[0041] Among them, multiple partition chambers 20 are arranged at intervals in the pickling tank II / alkali washing tank II, and the upper end of the partition chamber 20 is required to be higher than the liquid level in the pickling tank II / alkali washing tank II.

[0042] In addition, the upper end of the partition cavity 20 is open, and the upper cavity of the partition cavity 20 is further divided into multiple small cavities 21, which are connected to the pickling tank II / alkali washing tank II via the lower part of the partition cavity 20.

[0043] a. During normal pickling / alkaline washing in pickling tank II / alkaline washing tank II, all rollers 10 rotate in one direction (e.g., all counterclockwise), which pushes the liquid at the surface of pickling tank II / alkaline washing tank II to flow to the right. However, since the height of the partition chamber 20 is higher than the liquid surface height, the liquid flowing to the right is blocked by the partition chamber 20 and cannot continue to flow backward. Therefore, the mutual interference between the liquid surfaces pushed by each roller 10 is reduced, resulting in small fluctuations in the liquid surface of pickling tank II / alkaline washing tank II. Even if there are corresponding fluctuations in the liquid surface between two adjacent partition chambers 20, these fluctuations are not complex (compared to the mutual interference between the liquid surfaces pushed by each roller 10). Thus, by controlling the rotation speed of the rollers 10, the amount of acid / alkaline solution adhering to the rollers 10 can be controlled more accurately (without the partition chamber 20, the fluctuations would be complex and the degree of fluctuation would be difficult to control).

[0044] b. When roller 10 rotates, it will cause some liquid (small droplets) to splash, and the splashed liquid will fall into the small cavity 20. Then the liquid in the small cavity 20 can flow back to the pickling tank II / alkali washing tank II. This prevents the splashed liquid from aggravating the "fluidity generated when the roller 10 rotates and pushes the liquid surface to flow". Even if the liquid in the small cavity 20 flows back to the pickling tank II / alkali washing tank II, this part of the liquid flows from the bottom to the top, and the flow direction is relatively simple, which will not excessively aggravate the liquid surface fluctuation (compared to the design without partitioned cavity 20).

[0045] c. In layman's terms, this solution reduces the complexity of the actions at the liquid surface in pickling tank II / alkali washing tank II, thereby reducing the fluctuation of the liquid surface and making the fluctuation of the liquid surface more controllable. This makes the amount of acid / alkali liquid adhering to the roller 10 in one rotation more controllable, thus more accurately controlling the etching degree of the bottom surface of the solar panel and improving quality control.

[0046] In this embodiment, an auxiliary through hole 22 extending through the left and right sides is provided in the lower part of the partition cavity 20. This allows the liquid in the acid washing tank II / alkaline washing tank II to be separated by the partition cavity 20 (which reduces liquid surface fluctuations), while the liquid in the lower part flows through the auxiliary through hole 22 (which ensures that the alkali / acid concentration areas in the acid washing tank II / alkaline washing tank II are consistent – ​​because the amount of alkali / acid consumed by each solar panel may vary slightly, it is necessary to keep the liquid in the acid washing tank II / alkaline washing tank II flowing smoothly).

[0047] In this embodiment, the partition chamber 20 includes an upper chamber and a lower chamber that are interconnected. The upper chamber is divided into multiple small chambers 21, and the lower chamber has auxiliary through holes 22 that extend from left to right on its wall. When the roller 20 rotates, small droplets splashed into the small chambers 21 and then flow back into the pickling tank II / alkali washing tank II through the auxiliary through holes 22. During operation, the small chambers 21 are connected to the pickling tank II / alkali washing tank II through the auxiliary through holes 22 (located near the bottom of the tank). The purpose is that when droplets fly into the small chambers 21, a corresponding amount of liquid is discharged from the lower part of the partition chamber 20 through the auxiliary through holes 22. (The liquid can flow back. Since it flows back from the bottom, it will not cause too much fluctuation interference at the liquid surface and avoid increasing the complexity of liquid surface fluctuation. Even if this backflow will cause liquid surface fluctuation, the effect is relatively simple. This simple effect can be controlled relatively well by continuously adjusting (adjusting the rotation speed of the roller 10).

[0048] The partition cavity component 20 will be further described below.

[0049] See Figure 3 , Figure 4 , Figure 5 The partition cavity 20 is a rectangular cavity formed by splicing a left plate, a right plate, a front plate, a rear plate, and a bottom plate, and the top of the rectangular cavity is open; the bottom plate is in contact with the inner bottom surface of the pickling tank II / alkali washing tank II, and the front plate and the rear plate are in contact with the corresponding walls of the pickling tank II / alkali washing tank II.

[0050] Furthermore, a horizontal plate 23 is provided at the upper part of the interior of the partition cavity 20, which divides the interior of the partition cavity 20 into an upper cavity and a lower cavity; and multiple vertical plates 24 are arranged parallel and spaced apart in the upper cavity, which divides the upper cavity into multiple small cavities 21. Multiple through holes 2301 are opened in the horizontal plate 23 in the vertical direction, and the small cavities 21 communicate with the lower cavity through the through holes; in addition, multiple auxiliary through holes 22 are opened at the lower part of the left and right plates of the lower cavity.

[0051] During operation, the liquid splashed into the small cavity 21 can flow back into the pickling tank II / alkali washing tank II through the through hole 2301, the lower cavity, and the auxiliary through hole 22; the liquid in the pickling tank II / alkali washing tank II in different parts on the left and right sides can flow to each other through the auxiliary through hole 22.

[0052] The following section provides a further explanation of the configuration of the partition chamber 20 within the pickling tank II / alkali washing tank II.

[0053] See Figures 2-4 Within the pickling tank II / alkali washing tank II, a partition cavity 20 is provided on the side of each roller 10 that can raise splash droplets. This ensures that the liquid surface fluctuations caused by the pushing of each roller 10 and the fluctuations caused by splashing liquid can be effectively eliminated.

[0054] In this embodiment, the top of the partition chamber 20 is 0.3-2 cm higher than the liquid level in the acid washing tank II / alkali washing tank II.

[0055] Further design steps will be taken to reduce liquid surface fluctuations.

[0056] See Figure 4 An arc-shaped mesh 30 is provided below the roller 10 where it is immersed in the liquid surface, and the arc-shaped mesh 30 and the roller 20 are on the same axis, with a gap of 1-2 cm between them; in addition, the upper end of the arc-shaped mesh 30 is higher than the liquid surface but lower than the top of the partition cavity 20.

[0057] When the roller 10 rotates, the downward ripples of the liquid are weakened by the arc-shaped mesh 30; in addition, when liquid flows upward through the arc-shaped mesh 30, the ripples at the liquid surface are also weakened.

[0058] The above embodiments only illustrate preferred implementation methods, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A liquid level fluctuation prevention structure in a chain cleaning device for solar cell production, the chain cleaning device including an acid washing tank II / alkali washing tank II, wherein multiple rollers (10) are arranged at the liquid surface of the acid washing tank / alkali washing tank, and the lower part of the rollers (10) is immersed in the liquid surface, characterized in that: The pickling tank II / alkali washing tank II is provided with multiple partition chambers (20) spaced apart, and the upper end of the partition chamber (20) is higher than the liquid level in the pickling tank II / alkali washing tank II. The upper end of the partition cavity (20) is open, and the upper cavity of the partition cavity (20) is further divided into multiple small cavities (21), which are connected to the pickling tank II / alkali washing tank II through the lower part of the partition cavity (20). When the roller (10) rotates, the resulting fluctuations in the liquid surface are offset to a certain extent by the partition cavity component (20); When the roller (10) rotates, the splashed droplets fall into the small cavity (21) and eventually flow back to the pickling tank II / alkali washing tank II.

2. The anti-liquid level fluctuation structure in the chain cleaning equipment for solar cell production according to claim 1, characterized in that: The lower part of the partition cavity component (20) has an auxiliary through hole (22) that extends from left to right. In the pickling tank II / alkali washing tank II, the liquid in the upper part is separated by the partition chamber (20), and the liquid in the lower part flows through the auxiliary through hole (22).

3. The anti-liquid level fluctuation structure in the chain cleaning equipment for solar cell production according to claim 1 or 2, characterized in that: The partition cavity component (20) includes an upper cavity and a lower cavity that are interconnected; The upper cavity is divided into multiple small cavities (21), and the lower cavity has auxiliary through holes (22) that extend from left to right on its wall. When the roller (10) rotates, the splashed droplets fall into the small cavity (21) and then flow back to the pickling tank II / alkali washing tank II through the auxiliary through hole (22).

4. The anti-liquid level fluctuation structure in the chain cleaning equipment for solar cell production according to claim 3, characterized in that: The partition cavity component (20) is a rectangular cavity formed by splicing a left plate, a right plate, a front plate, a rear plate, and a bottom plate, and the top of the rectangular cavity is open; The partition cavity component (20) has a horizontal plate (23) at its upper part. The horizontal plate (23) divides the interior of the partition cavity component (20) into an upper cavity and a lower cavity. Multiple through holes (2301) are opened in the horizontal plate (23) along the vertical direction. The upper cavity is divided into multiple small cavities (21) by multiple vertical plates (24) spaced apart, forming a structure in which the liquid surfaces of the multiple small cavities (21) do not interfere with each other; multiple auxiliary through holes (22) are opened on the left and right side walls of the lower cavity.

5. The anti-liquid level fluctuation structure in the chain cleaning equipment for solar cell production according to claim 1, characterized in that: In the aforementioned pickling tank II / alkali washing tank II, a partition cavity (20) is provided on the side of each roller (10) that can raise splash droplets.

6. The anti-liquid level fluctuation structure in the chain cleaning equipment for solar cell production according to claim 1, characterized in that: The top of the partition chamber (20) is 0.3-2 cm higher than the liquid level in the acid washing tank II / alkali washing tank II.

7. The anti-liquid level fluctuation structure in the chain cleaning equipment for solar cell production according to claim 1, characterized in that: The roller (10) is provided with an arc-shaped mesh (30) below the part immersed in the liquid surface; The arc-shaped mesh (30) and the roller (10) are on the same axis, and there is a gap between them with a gap size of 1-2cm.

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