Boiler blowdown device

Abstract

A boiler blowdown device, comprising: a blowdown mechanism (100), comprising blowdown pipe (101), a maintenance pipe (102) communicated with the blowdown pipe (101), and a valve (103) provided on the maintenance pipe (102); a removal mechanism (200), comprising a support frame (201) provided in the blowdown pipe (101), a movement rod (202) connected to the support frame (201), a power component (203) provided on the movement rod (202), dismounting / mounting components (204) connected to the movement rod (202), mounting arms (205) connected to the dismounting / mounting components (204), and rotary scraping plates (206) provided on the mounting arms (205); and a cleaning mechanism (300) comprising cleaning components (301) provided on the power component (203), and control components (302) connected to the cleaning components (301). Rapidly-flowing water drives the power component (203) to rotate, the rotation of the power component (203) drives the movement rod (202) to rotate and also drives the rotary scraping plates (206) on the mounting arms (205) to be fitted with a transition section of the blowdown pipe (101), and in this case, the rotary scraping plates (206) enable sediment to be removed from the transition section of the blowdown pipe (101) through rotation.

Description

Boiler blowdown device

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202410728471.8, filed on June 6, 2024, and entitled "A boiler blowdown device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of boiler blowdown, and in particular to a boiler blowdown device. BACKGROUND

[0004] The coal circulating fluidized bed boiler is a common type of coal-fired boiler, which uses circulating fluidized bed technology for combustion and has high combustion efficiency, achieving effective utilization of heat energy. When the boiler is running, it will produce wastewater containing pollutants, such as cooling water and boiler descaling wastewater. These wastewaters contain high concentrations of heavy metals, organic matter and other harmful substances, which need to be treated before being discharged.

[0005] Due to the large amount of sediment contained in the wastewater, when the wastewater flows through the transition section of the blowdown pipeline, the diameter of the pipeline changes from large to small, and the sediment is easy to deposit and accumulate in the transition section. With the passage of time, it will gradually accumulate to form a blockage.

[0006] SUMMARY

[0007] This section is intended to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the title of the application in order to avoid obscuring the purpose of this section, the abstract of the specification and the title of the application, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0008] In view of the above-mentioned problem that the wastewater is easy to deposit and accumulate when flowing through the transition section of the blowdown pipeline, the present application is proposed.

[0009] Therefore, the purpose of the present application is to provide a boiler blowdown device.

[0010] To solve the above technical problems, the application provides the following technical scheme: a boiler blowdown device, comprising a blowdown mechanism, a cleaning mechanism and a cleaning mechanism; the blowdown mechanism comprises a blowdown pipeline, an inspection pipeline communicated with the blowdown pipeline, and a valve arranged on the inspection pipeline; the cleaning mechanism comprises a support frame arranged in the blowdown pipeline, a moving rod connected with the support frame, a power component arranged on the moving rod, a dismounting component connected with the moving rod, a mounting arm connected with the dismounting component, and a rotating scraper arranged on the mounting arm; and the cleaning mechanism comprises a cleaning component arranged on the power component and a control component connected with the cleaning component.

[0011] As an optional solution of the boiler blowdown device, the power component comprises a rotating cylinder connected with the moving rod, a fan blade connected with the rotating cylinder, a baffle connected with the moving rod, and a power spring arranged on the side of the moving rod.

[0012] As an optional solution of the boiler blowdown device, the cleaning component comprises a cleaning spring connected with the rotating cylinder and a moving scraper connected with the cleaning spring.

[0013] As an optional solution of the boiler blowdown device, the cleaning component further comprises a reinforcing rib arranged on the fan blade and a guide groove opened on the moving scraper; the moving scraper is sleeved on the fan blade and slides along the reinforcing rib through the guide groove.

[0014] As an optional solution of the boiler blowdown device, the control component comprises a storage box arranged on the fan blade, a storage cavity opened in the storage box, a grab hook arranged in the storage cavity, control springs respectively connected with the storage cavity and the grab hook, and a control groove opened in the moving scraper.

[0015] As an optional solution of the boiler blowdown device, the grab hook is provided with an inclined surface at the hook end, and the control groove is provided with a control protrusion.

[0016] As an optional solution of the boiler blowdown device, the dismounting component comprises a connecting block connected with the mounting arm, a mounting seat arranged on the connecting block, a rotating gear arranged on the mounting seat, a rotating plate coaxially arranged with the rotating gear, a containing groove opened on the connecting block, a rack arranged in the containing groove, and a limiting assembly arranged on the connecting block.

[0017] As an optional solution of the boiler blowdown device, the rotating plate is an arc-shaped plate, and the containing groove has an "L" shaped cross section.

[0018] As an optional solution of the boiler blowdown device, the limiting assembly comprises a limiting spring arranged in the accommodating groove, a limiting plate connected with the limiting spring, and a lifting section and a limiting groove formed on the rotating plate.

[0019] As an optional solution of the boiler blowdown device, the dismounting component is arranged in a circular array with two groups of moving rods, two connecting blocks cooperatively form a disc, the disc is provided with a positioning groove, and the moving rods are provided with positioning protrusions.

[0020] The boiler blowdown device has the following advantages: the water flow drives the power component to rotate, the rotation of the power component drives the moving rods to rotate, and the rotating scraper on the mounting arm is in close contact with the transition section of the blowdown pipeline, so that the rotating scraper removes the deposits on the transition section of the blowdown pipeline through rotation, thereby avoiding the blockage of the blowdown pipeline; the fast-rotating power component triggers the control component, and the control component releases the limiting of the cleaning component, so that the cleaning component is thrown out due to the centrifugal force generated by rotation to clean the power component, thereby prolonging the service life. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Fig. 1 is a schematic diagram of a blowdown mechanism of a boiler blowdown device.

[0023] Fig. 2 is a schematic diagram of a cleaning structure and a cleaning mechanism of a boiler blowdown device.

[0024] Fig. 3 is a schematic diagram of a cleaning component of a boiler blowdown device from a first perspective.

[0025] Fig. 4 is a schematic diagram of a cleaning component of a boiler blowdown device from a second perspective.

[0026] Fig. 5 is a schematic diagram of a control component of a boiler blowdown device.

[0027] Fig. 6 is a schematic diagram of a dismounting component of a boiler blowdown device.

[0028] Fig. 7 is an exploded schematic diagram of a dismounting component of a boiler blowdown device.

[0029] Fig. 8 is a sectional view of a connecting block of a boiler blowdown device.

[0030] Fig. 9 is an exploded schematic diagram of a limiting assembly of a boiler blowdown device.

[0031] Figure 10 is a schematic view of a boiler blowdown apparatus prior to assembly of the disassembly component. DETAILED DESCRIPTION

[0032] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application, however, can be practiced in a variety of ways beyond the specific details set forth herein without departing from the scope of the present application, and it is understood that the present application is intended to cover all modifications and variations of this application. Accordingly, the application is not limited to the specific embodiments described below.

[0034] Second, the "one embodiment" or "an embodiment" as referred to herein means a specific feature, structure, characteristic, or combination of features and characteristics described in at least one implementation of the present application. The "in one embodiment" appearing in various places in the specification are not all referring to the same embodiment, nor are they mutually exclusive of other embodiments.

[0035] Third, the present application is described in detail with reference to the accompanying drawings. In the detailed description of the embodiments of the present application, the sectional view of the device structure is partially enlarged without the general proportion for the convenience of explanation, and the schematic view is only an example which should not limit the scope of the present application. In addition, the three-dimensional spatial dimensions including length, width and depth should be included in the actual manufacture.

[0036] Example 1

[0037] Referring to FIG. 1-2, for the first embodiment of the present application, the embodiment provides a boiler blowdown device, comprising, a blowdown mechanism 100, comprising a blowdown pipeline 101, wherein the blowdown pipeline 101 is a variable-diameter pipeline, wastewater flows to a sedimentation tank and other treatment facilities through the blowdown pipeline 101, an inspection pipeline 102 in communication with the blowdown pipeline 101, wherein the inspection pipeline 102 is provided to facilitate inspection of the blowdown pipeline 101 and facilitate replacement of parts in the blowdown pipeline 101, a valve 103 provided on the inspection pipeline 102, wherein the valve 103 is used to control opening and closing of the inspection pipeline 102; a cleaning mechanism 200, comprising a support frame 201 fixedly arranged in the blowdown pipeline 101, wherein the support frame 201 has a "Y" shaped cross section and is used to support a moving rod 202, the moving rod 202 connected with the support frame 201, wherein the moving rod 202 is in sliding connection with the support frame 201 and can rotate in the support frame 201, a power component 203 provided on the moving rod 202, wherein the power component 203 drives a rotating scraper 206 to move and rotate through the moving rod 202, a disassembly component 204 connected with the moving rod 202, wherein the rotating scraper 206 can be quickly replaced through the disassembly component 204 due to its relatively fast friction loss speed, an installation arm 205 connected with the disassembly component 204, wherein the installation arm 205 is provided to provide space and support for installation of the rotating scraper 206, the rotating scraper 206 fixedly arranged on the installation arm 205, wherein the rotating scraper 206 scrapes off deposits on the transition section of the blowdown pipeline 101 through rotation; and, a cleaning mechanism 300, comprising a cleaning component 301 provided on the power component 203, wherein the cleaning component 301 is used to clean the power component 203 to prolong the service life of the power component 203, a control component 302 connected with the cleaning component 301, wherein the control component 302 has a limiting effect on the cleaning component 301, and the power component 203 needs to reach a certain rotating speed to enable the control component 302 to release the limiting effect on the cleaning component 301.

[0038] Specifically, the power component 203 includes a rotating cylinder 203a fixedly connected with the moving rod 202, wherein the rotating cylinder 203a is used to expand the installation area of the fan blades 203b, and a plurality of fan blades 203b fixedly connected with the rotating cylinder 203a, wherein the fan blades 203b rotate when impacted by the rapidly flowing water flow, thereby driving the rotating cylinder 203a, the moving rod 202, the mounting arm 205, and the rotating scraper 206 to rotate; at the same time, the above parts are brought close to the transition section of the blowdown pipe 101, so that the rotating scraper 206 is attached to the transition section of the blowdown pipe 101, and the baffle 203c fixedly connected with the moving rod 202 and the power spring 203d arranged on the side of the moving rod 202, wherein one end of the power spring 203d is fixedly connected with the baffle 203c, and the other end of the power spring 203d is rotatably connected with the support frame 201, when the moving rod 202 moves due to the impact of the water flow on the fan blades 203b, the power spring 203d is elongated, and when the water flow stops impacting the fan blades 203b, the power spring 203d drives the moving rod 202 to reset.

[0039] Operation process: by periodically injecting rapidly flowing water into the blowdown pipe 101, the sediment in the blowdown pipe 101 can be periodically cleaned, wherein the flow rate of the rapidly flowing water is faster than that of the wastewater, the water flow impacts the fan blades 203b, so that the fan blades 203b, the rotating cylinder 203a, the moving rod 202, the mounting arm 205, and the rotating scraper 206 move along the support frame 201 until the rotating scraper is attached to the transition section of the blowdown pipe 101, at this time the power spring 203d is elongated, and at the same time the fan blades 203b are rotated under the impact of the water flow, thereby driving the rotating cylinder 203a, the moving rod 202, the mounting arm 205, and the rotating scraper 206 to rotate, at this time the rotating scraper 206 removes the sediment on the transition section of the blowdown pipe 101, avoiding the blockage of the blowdown pipe 101, when the water flow stops injecting, the power spring 203d returns to its original state and drives the fan blades 203b, the rotating cylinder 203a, the moving rod 202, the mounting arm 205, and the rotating scraper 206 to reset, at this time the rotating scraper 206 is separated from the transition section of the blowdown pipe 101, and when the wastewater impacts the fan blades 203b, due to the flow rate problem, the impact force is not enough to make the rotating scraper 206 attached to the transition section of the blowdown pipe 101, which can prolong the service life of the scraper;

[0040] Since the rapidly flowing water needs to be prepared in advance, in order to avoid cleaning in time, an external motor can also be used as a power to drive the fan blades 203b to rotate, accordingly the position and installation mode of the moving rod 202 need to be adjusted, so that the initial position of the rotating scraper 206 is attached to the transition section of the blowdown pipe 101, and the moving rod 202 and the support frame 201 can only rotate, not move.

[0041] Embodiment 2

[0042] Referring to FIG. 3-5, for the second embodiment of the present application, the difference between the second embodiment and the first embodiment is that the cleaning component 301 comprises a cleaning spring 301a fixedly connected with the rotating cylinder 203a, wherein the cleaning spring 301a is stretched with the movement of the moving scraper 301b, and the moving scraper 301b fixedly connected with the cleaning spring 301b is moved by the centrifugal force generated when the fan blade 203b rotates, so as to clean the fan blade 203b.

[0043] Specifically, the cleaning component 301 further comprises a reinforcing rib 301c arranged on the fan blade 203b, wherein the reinforcing rib 301c is integrally formed with the fan blade 203b, the reinforcing rib 301c can improve the strength of the fan blade 203b, a guide groove 301d arranged on the moving scraper 301b, and the reinforcing rib 301c is in sliding connection with the guide groove 301d; wherein the moving scraper 301b is sleeved on the fan blade 203b and slides along the reinforcing rib 301c through the guide groove 301d.

[0044] Optionally, the control component 302 comprises a storage box 302a fixedly arranged on the fan blade 203b, a storage cavity 302b arranged in the storage box 302a, a hook 302c in rotational connection with the inner wall of the storage cavity 302b, wherein the fast-flowing water makes the fan blade 203b rotate, the hook 302c is rotated away from the control protrusion 302g under the influence of the centrifugal force generated by the rotation of the fan blade 203b, a control spring 302d connected with the storage cavity 302b and the hook 302c respectively, the control spring 302d is stretched when the hook 302c rotates, and since the control spring 302d is arranged, the centrifugal force generated by the rotation of the fan blade 203b driven by the waste water flow is not enough to rotate the hook 302c away from the control protrusion 302g, a control groove 302e arranged in the moving scraper 301b, and the control groove 302e limits the rotation of the hook 302c.

[0045] Optionally, the hook end of the hook 302c is provided with an inclined surface 302f, the control groove 302e is provided with a control protrusion 302g, and the control spring 302d makes the hook end of the hook 302c abut against the control protrusion 302g.

[0046] The remaining structures are the same as those of the first embodiment.

[0047] The operation process is as follows: the fast flowing water drives the fan blade 203b to rotate rapidly, the centrifugal force generated by the rapid rotation of the fan blade 203b drives the hook 302c to rotate away from the control protrusion 302g, at this time the control spring 302d is elongated, and the centrifugal force will throw the movable scraper 301b outwards due to the lack of the hook 302c. At this time, the cleaning spring 301a is elongated, and the movable scraper 301b removes the dirt attached to the surface of the fan blade 203b during movement along the reinforcing rib 301c, prolonging the service life of the fan blade 203b. When the fast flowing water stops flowing into the sewage pipe 101, the fan blade 203b no longer rotates, the centrifugal force disappears, the control spring 302d drives the hook 302c to reset, and the cleaning spring 301a drives the movable scraper 301b to reset. With the resetting of the movable scraper 301b, the control protrusion 302g of the control groove 302e is in contact with the inclined surface 302f of the hook 302c, the cleaning spring 301a drives the control protrusion 302g to press the inclined surface 302f, so that the hook 302c is away from the control protrusion 302g, until the control protrusion 302g is separated from the inclined surface 302f. At this time, the movable scraper 301b continues to move, and the hook 302c enters the control groove 302e. Then the control spring 302d drives the hook 302c to reset again, so that the hook 302c is in contact with the control protrusion 302g.

[0048] Embodiment 3

[0049] Referring to FIGS. 6-10, the third embodiment of the present application is different from the above embodiments in that the dismounting part 204 includes two connection blocks 204a fixedly connected with the mounting arm 205, wherein the two connection blocks 204a are clamped on the side of the moving rod 202 from the upper and lower directions respectively, a mounting seat 204b fixedly arranged on the connection block 204a, a rotating gear 204c rotationally connected with the mounting seat 204b, a rotating plate 204d coaxially arranged with the rotating gear 204c and fixedly connected with the rotating gear 204c, so that the rotating plate 204d rotates when the rotating gear 204c rotates, a receiving groove 204e opened on the connection block 204a, a rack 204f fixedly arranged in the receiving groove 204e, wherein the rack 204f is engaged with the rotating gear 204c, and a limiting assembly 204g arranged on the connection block 204a, wherein the limiting assembly 204g is used to limit the rotating plate 204d.

[0050] Specifically, the rotating plate 204d is an arc-shaped plate, one end of the arc-shaped plate is fixedly connected with the rotating gear 204c, the other end of the arc-shaped plate is provided with a lifting section 204g-3 and a limiting groove 204g-4, the cross section of the receiving groove 204e is “L” shaped, so as to facilitate the rotation of the rotating plate 204d in the receiving groove 204e, and the initial state of the rotating plate 204d is vertical state, which is affected by the rotating gear 204c and the rack 204f to rotate 60°.

[0051] Optionally, the limiting component 204g includes a limiting spring 204g-1 fixed in the accommodating groove 204e, wherein the limiting spring 204g-1 is provided with two, and the limiting spring 204g-1 is deformed when the limiting plate 204g-2 is displaced, and the limiting plate 204g-2 is fixedly connected with the limiting spring 204g-1, wherein the limiting plate 204g-2 is slidable through the connecting block 204a, the lifting section 204g-3 and the limiting groove 204g-4 are opened on the rotating plate 204d, with the rotation of the rotating plate 204d, the lifting section 204g-3 will lift the limiting plate 204g-2, and when the limiting plate 204g-2 is flush with the limiting groove 204g-4, the limiting spring 204g-1 will restore the original state to pull the limiting plate 204g-2 into the limiting groove 204g-4, at this time, the rotating cup is limited and fixed.

[0052] Optionally, the disassembling component 204 is arranged in two groups with the moving rod 202 as the circumference, and the two connecting blocks 204a are matched to form a disc, the disc is provided with a positioning groove, and the moving rod 202 is provided with a positioning protrusion, wherein the positioning groove and the positioning protrusion are matched to position the connecting block 204a and the moving rod 202.

[0053] The remaining structures are the same as those in Example 2.

[0054] Operation process: the two disassembling components 204 are arranged on the upper and lower sides of the moving rod 202, the two connecting blocks 204a are close to each other to make the mounting seat 204b inserted into the accommodating groove 204e, at this time, the rotating gear 204c is engaged with the rack 204f, with the mounting seat 204b continuously inserted into the accommodating groove 204e, the rotating gear 204c is rotated, and the rotating plate 204d in the vertical state is rotated by 60°, and finally the mounting seat 204b is inserted into the vertical part of the accommodating groove 204e, the rotating plate 204d is turned into the horizontal part of the accommodating groove 204e, and in the rotating process of the rotating plate 204d, the lifting section 204g-3 will lift the limiting plate 204g-2 until the limiting plate 204g-2 is attached to the side surface of the rotating plate 204d, at this time, the limiting spring 204g-1 is elongated, and the rotating plate 204d is continuously rotated, and when the limiting plate 204g-2 is flush with the limiting groove 204g-4, the limiting spring 204g-1 will restore the original state to pull the limiting plate 204g-2 into the limiting groove 204g-4, at this time, the rotating plate 204d is limited and fixed, and after the two connecting blocks 204a and the moving rod 202 are fixed together, the limiting plate 204g-2 is extracted from the limiting groove 204g-4, at this time, the two connecting blocks 204a can be pulled apart.

[0055] It is important to note that the construction and arrangement of the application shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review the present disclosure will readily appreciate that many modifications can be made to the embodiments without departing from the spirit and scope of the application, as described in the claims (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc. and the like). For example, the position of elements can be reversed or otherwise varied, and the nature or number of elements can be altered or varied. Thus, all such modifications are intended to be included within the scope of the application. The order or sequence of any process or method steps can be varied or re-sequenced without departing from the spirit of the application. Any

[0056] In addition, for purposes of brevity of description, and not by way of limitation, full structural details of any of the elements shown in the various figures can not be repeated at every occurrence.

[0057] It is understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions can be made. Such development efforts can inevitably lead to modifications, not all of which can be foreseen at the time a patent application is filed. Such modifications are reserved, to the extent possible, by the following claims, the scope of which is to be accorded the broadest fair interpretation so as to encompass all equivalent structures and functions.

[0058] It should be noted that the above examples are intended to be illustrative only and not limiting of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those with ordinary skill in the art will appreciate that various modifications can be made without departing from the spirit and scope of the application as described in the claims.

Claims

1. A boiler blowdown apparatus, characterized by: Including, The blowdown mechanism (100) comprises a blowdown pipeline (101), an inspection pipeline (102) communicated with the blowdown pipeline (101), and a valve (103) arranged on the inspection pipeline (102); The cleaning mechanism (300) comprises a cleaning component (301) arranged on the power component (203), and a control component (302) connected with the cleaning component (301). The power component (203) comprises a rotating cylinder (203a) connected with the moving rod (202), a fan blade (203b) connected with the rotating cylinder (203a), a baffle (203c) connected with the moving rod (202), and a power spring (203d) arranged on the side of the moving rod (202).

2. A boiler blowdown apparatus as claimed in claim 1, characterised in that: The cleaning component (301) comprises a cleaning spring (301a) connected with the rotating cylinder (203a), and a moving scraper (301b) connected with the cleaning spring (301a).

3. A boiler blowdown apparatus as claimed in claim 2, wherein: The cleaning component (301) further comprises a reinforcing rib (301c) arranged on the fan blade (203b), and a guide groove (301d) opened on the moving scraper (301b).

4. A boiler blowdown apparatus as claimed in claim 3, wherein: The moving scraper (301b) is sleeved on the fan blade (203b) and slides along the reinforcing rib (301c) through the guide groove (301d). The control component (302) comprises a storage box (302a) arranged on the fan blade (203b), a storage cavity (302b) opened in the storage box (302a), a grab hook (302c) arranged in the storage cavity (302b), a control spring (302d) connected with the storage cavity (302b) and the grab hook (302c) respectively, and a control groove (302e) opened in the moving scraper (301b).

5. A boiler blowdown apparatus as claimed in claim 4, wherein: The hook end of the grab hook (302c) is provided with an inclined surface (302f), and the control groove (302e) is provided with a control protrusion (302g).

6. A boiler blowdown apparatus as claimed in claim 5, wherein: The dismounting component (204) comprises a connecting block (204a) connected with the mounting arm (205), a mounting seat (204b) arranged on the connecting block (204a), a rotating gear (204c) arranged on the mounting seat (204b), a rotating plate (204d) arranged coaxially with the rotating gear (204c), a containing groove (204e) opened on the connecting block (204a), a rack (204f) arranged in the containing groove (204e), and a limiting assembly (204g) arranged on the connecting block (204a).

7. A boiler blowdown apparatus as claimed in claim 1 or 6, characterised in that: ​ 8. A boiler blowdown apparatus as claimed in claim 7, wherein: The rotating plate (204d) is an arc-shaped plate, and the containing groove (204e) has an "L"-shaped cross section.

9. A boiler blowdown apparatus as claimed in claim 8, wherein: The limiting component (204g) comprises a limiting spring (204g-1) arranged in the containing groove (204e), a limiting plate (204g-2) connected with the limiting spring (204g-1), and a lifting section (204g-3) and a limiting groove (204g-4) formed on the rotating plate (204d).

10. A boiler blowdown apparatus as claimed in claim 9, wherein: The disassembling component (204) is arranged in two groups with the moving rod (202) as a circle, two connecting blocks (204a) cooperatively form a disc, the disc is provided with a positioning groove, and the moving rod (202) is provided with a positioning protrusion.

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