CN219508576U

CN219508576U - Rotary hopper

Info

Publication number: CN219508576U
Application number: CN202320633013.7U
Authority: CN
Inventors: 王玲杰; 李福年; 杨晓泰; 周学才
Original assignee: Yilihe Power Generation Factory Of Huadian Yunnan Power Generation Co ltd
Current assignee: Yilihe Power Generation Factory Of Huadian Yunnan Power Generation Co ltd
Priority date: 2023-03-28
Filing date: 2023-03-28
Publication date: 2023-08-11
Anticipated expiration: 2033-03-28

Abstract

The utility model discloses a rotary hopper, which relates to the technical field of concrete conveying in constructional engineering and comprises a conveying pipe, a buffer pipe and a buffer assembly; the two ends of the buffer tube are respectively provided with a first bent tube and a second bent tube, the first bent tube and the second bent tube are mutually parallel and reversely arranged, and the two ends of the first bent tube and the second bent tube are respectively connected with the two ends of the conveying tube to connect different conveying tubes in parallel and in a staggered way; the buffer assembly comprises a first buffer part arranged on the inner wall of the first elbow and a second buffer part arranged on the inner wall of the second elbow, and the first buffer part and the second buffer part are used for buffering the impact of concrete conveyed in the conveying pipe on the conveying pipe, the first elbow and the second elbow; the flow direction of the concrete in each section of conveying pipe is changed through the buffer pipe, the flow speed of the concrete is reduced under the buffer action of the first buffer part and the second buffer part, the phenomenon that the concrete is separated from aggregate is avoided, the circulation channel of the concrete is ensured, and the concrete is prevented from being blocked in the conveying process.

Description

Rotary hopper

Technical Field

The utility model relates to the technical field of concrete conveying in constructional engineering, in particular to a rotary hopper.

Background

The shaft is a well-shaped pipeline with an upright hole wall, and is actually a collapse funnel. Square, elongated or irregularly circular above the planar profile. The well wall is steep and nearly vertical. The vertical shaft is widely applied to water taking, water diversion, ventilation, slag sliding and air supplementing of water conservancy and hydropower engineering, and the vertical shaft construction has the characteristics of small occupied area, less interference to peripheral construction and the like.

In the construction process of the vertical shaft, a construction mode of excavating a section and supporting a section is adopted, in the support process, concrete is conveyed to the section to be supported in the vertical shaft to be poured in a pipeline or direct pumping mode, but the vertical construction depth is larger, the construction of the vertical shaft exceeding 100 meters is common, when the height difference exceeds 25 meters in the concrete conveying process, the conveyed concrete is easy to have the condition of aggregate separation or pipe blockage, and when the concrete has the aggregate separation, the poured concrete strength is influenced; when the condition of pipe blockage occurs in the conveying process, the construction quality and the construction progress are affected.

The utility model patent number CN203924069U discloses a shaft concrete conveying descent control device, wherein a slow flow baffle plate and a longitudinal baffle plate are arranged in a concrete conveying pipeline to slow down the falling speed in the concrete conveying process, so that aggregate separation in the concrete conveying process is avoided, but in the patent, the inner space of the concrete pipeline can be reduced by arranging the slow flow baffle plate in the concrete conveying pipeline, so that the space for concrete circulation is reduced, and the condition of pipe blockage easily occurs in the concrete conveying process, thereby influencing the construction progress.

The foregoing is provided merely for the purpose of facilitating an understanding of the present utility model and is not intended to represent the closest prior art to the foregoing.

Disclosure of Invention

The utility model mainly aims to provide a rotary hopper which is used for solving the problems that concrete aggregate separation and concrete conveying pipe blockage are easy to occur when concrete is conveyed in the existing shaft construction.

To achieve the above object, the present utility model provides a rotary hopper including:

the two ends of the conveying pipe are respectively provided with a first conveying joint and a second conveying joint;

the buffer tube is provided with a first bent tube and a second bent tube at two ends respectively; the two ends of the first bent pipe and the second bent pipe are respectively connected with the two ends of the conveying pipes so as to connect different conveying pipes in parallel and in a staggered manner, and two groups of coaxially arranged pipeline structures are formed between the conveying pipes positioned on the two sides of the buffer pipe;

the buffer assembly comprises a first buffer part arranged on the central circular arc-shaped inner wall of the first bent pipe and a second buffer part arranged on the central circular arc-shaped inner wall of the second bent pipe; the first buffer part and the second buffer part are used for buffering the impact of the concrete conveyed in the conveying pipe on the conveying pipe, the first bent pipe and the second bent pipe.

Further, the first elbow comprises a first pipe section connected with the first buffer joint, a second pipe section connected with the buffer pipe, and a first central pipe section connecting the first pipe section and the second pipe section; the inner diameter of the first pipe section is consistent with the inner diameter of the conveying pipe; the inner diameter of the second pipe section is consistent with the inner diameter of the buffer pipe; the inner diameter of the first central pipe section is larger than the inner diameters of the first pipe section and the second pipe section; the second elbow comprises a third pipe section connected with the second buffer joint, a fourth pipe section connected with the buffer pipe, and a second central pipe section connected with the third pipe section and the fourth pipe section; the inner diameter of the third pipe section is consistent with the inner diameter of the conveying pipe; the inner diameter of the fourth pipe section is consistent with the inner diameter of the buffer pipe; the inner diameter of the second central pipe section is larger than that of the third pipe section and the fourth pipe section.

Further, the first central pipe section connecting the first pipe section and the second central pipe section connecting the third pipe section and the fourth pipe section are arc-shaped.

Further, the inner diameter of the buffer tube is consistent with that of the first central tube section, and the buffer tube is obliquely arranged in a direction away from the conveying tube connected with the first bent tube.

Further, the distance between the conveying pipes on two sides of the buffer pipe and the buffer pipe is arranged on two sides of the buffer pipe in a coaxial mode in sequence.

Further, the first buffer part comprises a first buffer block arranged on the inner wall of the lower half part of the first pipe section; the first buffer block is arranged away from the end face which is not attached to the first central pipe section and is inclined to the center of the conveying pipe, and the first buffer block guides concrete into the buffer pipe while relieving the impact of the concrete; the second buffer part comprises a second buffer block arranged on the inner wall of the upper half part of the second pipe section; the second buffer block is far away from the end face which is not attached to the first central pipe section and is inclined to the center of the conveying pipe, and the second buffer block guides the concrete into the conveying pipe while relieving the impact of the concrete.

Further, a third buffer part is arranged on the pipe wall of the upper half part of the buffer pipe facing the conveying pipe; the third buffer portion is used for buffering impact of concrete to the upper half part of the buffer tube after the concrete enters the buffer tube.

Further, a convolution part is arranged on the outer bending wall of the second bending pipe; the convolution part is used for guiding the concrete to fall after the concrete moves upwards and to be impacted with the concrete flowing out of the buffer tube so as to slow down the flow velocity of the concrete.

Further, a first transition pipe is arranged at the end of the conveying pipe connected with the first pipe section; a second transition pipe is arranged at one end of the third pipe section, which is connected with the conveying pipe; a first countersunk groove matched with the first transition pipe is formed in the first pipe section; and a second countersunk head groove matched with the second transition pipe is formed in one end, connected with the third pipe section, of the conveying pipe.

Further, the convolution part comprises a circular arc-shaped convolution surface; the lower end of the rotating surface is connected with the fourth pipe section, and the upper end of the rotating surface is connected with the third pipe section.

The beneficial effects of the utility model are as follows:

the buffer tube is used for separating the conveying tube with larger drop into a plurality of sections, the flow direction of concrete in each section of conveying tube is changed under the separation of the buffer tube, the flow speed of the concrete is reduced under the buffer action of the first buffer part and the second buffer part after the concrete enters the buffer tube, so that the phenomenon that aggregate is separated due to larger drop is avoided, meanwhile, the impact of the concrete on the buffer tube is buffered through the first buffer part and the second buffer part, and the flow channel of the concrete is ensured under the condition that the flow inner diameter of the concrete is not changed, and the blocking of the concrete in the conveying process is avoided.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a rotary hopper of the present utility model after connection;

FIG. 2 is a schematic diagram of a conveying pipe structure of a rotary hopper according to the present utility model;

FIG. 3 is a schematic diagram of a connection structure of a first elbow and a second elbow of a rotary hopper;

FIG. 4 is a schematic diagram of a buffer portion of a rotary hopper according to the present utility model;

FIG. 5 is a schematic view of a first transition pipe provided with a rotary hopper according to the present utility model;

FIG. 6 is a schematic view of a second transition pipe provided with a rotary hopper according to the present utility model;

FIG. 7 is a schematic view of a gyratory part structure provided with a gyratory hopper according to the present utility model;

FIG. 8 is a schematic view of the internal structure of a gyratory hopper according to the present utility model;

reference numerals illustrate:

1. a delivery tube; 101. a first delivery joint; 102. a second delivery joint; 2. a buffer tube; 201. a first elbow; 2011. a first buffer joint; 2012. a first pipe section; 2013. a second pipe section; 2014. a first center tube segment; 202. a second elbow; 2021. a second buffer joint; 2022. a third pipe section; 2023. a fourth pipe section; 2024. a second center tube segment; 3. a first buffer section; 4. a second buffer section; 5. a third buffer section; 6. a first transition tube; 7. a second transition tube; 8. a first countersunk head groove; 9. a second countersunk head groove; 10. a convolution.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the described embodiments are merely some, but not all embodiments of the present utility model. Embodiments of the utility model and features of the embodiments may be combined with each other without conflict. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In one embodiment, referring to fig. 1, a rotary hopper of the present utility model includes a transfer tube 1, a buffer tube 2, and a buffer assembly.

Referring to fig. 1 and 2, a first conveying joint 101 and a second conveying joint 102 are respectively arranged at two ends of a conveying pipe 1, a first bent pipe 201 and a second bent pipe 202 are respectively arranged at two ends of a buffer pipe 2, one ends of the first bent pipe 201 and the second bent pipe 202, which are far away from the buffer pipe 2, are mutually parallel and reversely arranged, a first buffer joint 2011 is arranged on the first bent pipe 201, a second buffer joint 2021 is arranged on the second bent pipe 202, and two ends of the first bent pipe 201 and the second bent pipe 202 are respectively connected with two ends of the conveying pipe 1 so as to connect different conveying pipes 1 in parallel and in a staggered manner; two groups of pipeline structures which are coaxially arranged are formed between the conveying pipes 1 positioned on two sides of the buffer pipe 2; the buffer assembly comprises a first buffer part 3 arranged on the central circular arc-shaped inner wall of the first elbow pipe 201 and a second buffer part 4 arranged on the central circular arc-shaped inner wall of the second elbow pipe 202, wherein the first buffer part 3 and the second buffer part 4 are used for buffering the impact of concrete conveyed in the conveying pipe 1 on the conveying pipe 1, the first elbow pipe 201 and the second elbow pipe 202.

Further, referring to fig. 3, the first elbow 201 includes a first pipe segment 2012 connected to the first buffer joint 2011, a second pipe segment 2013 connected to the buffer tube 2, and a first center pipe segment 2014 connecting the first pipe segment 2012 and the second pipe segment 2013, an inner diameter of the first pipe segment 2012 being consistent with an inner diameter of the delivery pipe 1, an inner diameter of the second pipe segment 2013 being consistent with an inner diameter of the buffer tube 2, an inner diameter of the first center pipe segment 2014 being greater than inner diameters of the first pipe segment 2012, the second pipe segment 2013; the second elbow 202 includes a third pipe section 2022 connected to the second buffer joint 2021, a fourth pipe section 2023 connected to the buffer pipe 2, and a second center pipe section 2024 connecting the third pipe section 2022 and the fourth pipe section 2023, an inner diameter of the third pipe section 2022 being identical to an inner diameter of the conveying pipe 1, an inner diameter of the fourth pipe section 2023 being identical to an inner diameter of the buffer pipe 2, an inner diameter of the second center pipe section 2024 being larger than inner diameters of the third pipe section 2022 and the fourth pipe section 2023.

Preferably, referring to fig. 3, the first central pipe section 2014 connecting the first pipe section 2012 and the second pipe section 2013 and the second central pipe section 2024 connecting the third pipe section 2022 and the fourth pipe section 2023 are circular arcs; the first conveying connector 101, the second conveying connector 102 and the conveying pipe 1 and the first buffer connector 2011 and the second buffer connector 2021 are connected with the first elbow 201 and the second elbow 202 in a welding mode, the first buffer connector 2011, the second buffer connector 2021, the first conveying connector 101 and the second conveying connector 102 are all flange plates, connecting screw holes are formed in the flange plates at intervals, and bolts penetrate through the connecting screw holes to connect the first buffer connector 2011 with the first conveying connector 101 and the second buffer connector 2021 with the second conveying connector 102; the buffer tube 2 may be welded or integrally formed with the second tube section 2013 of the first elbow 201 and with the third tube section 2022 of the second elbow 202.

Preferably, the first bent pipe 201 formed by the first pipe section 2012, the second pipe section 2013 and the first central pipe section 2014 has an "L" shape, and the second bent pipe 202 formed by the third pipe section 2022, the fourth pipe section 2023 and the second central pipe section 2024 has an "L" shape.

Further, referring to fig. 1 and 3, the buffer tube 2 has an inner diameter that matches the inner diameter of the first center tube section 2014, and the buffer tube 2 is disposed obliquely in a direction away from the delivery tube 1 connected to the first elbow 201.

Preferably, the angle at which buffer tube 2 is inclined away from delivery tube 1 is achieved by varying the angle of bend of first center tube segment 2014 on first elbow 201.

For example, the buffer tube 2 is inclined at 135 ° with respect to the delivery tube 1, and by changing the angle between the first pipe section 2012 and the second pipe section 2013 of the first elbow 201 to 135 °, the angle of the first elbow 201 is preset at the time of manufacturing the first elbow 201.

Further, referring to fig. 1, the transport tubes 1 on both sides of the buffer tube 2 are sequentially coaxially disposed on both sides of the buffer tube 2 at a distance of one buffer tube 2.

Further, referring to fig. 4, the first buffer portion 3 includes a first buffer block provided on the inner wall of the lower half of the first pipe section 2012, the first buffer block being provided inclined from the center of the conveying pipe 1 away from the end face which is not attached to the first center pipe section 2014, the first buffer block guiding the concrete into the buffer pipe 2 while reducing the impact of the concrete.

Preferably, referring to fig. 4, the end surface of the first buffer block, which is attached to the first central pipe section 2014, is in a circular arc shape that fits the inner wall of the first central pipe section 2014, the end surface of the first buffer block, which is not attached to the first central pipe section 2014, is in a straight surface, and the concrete falling in the conveying pipe 1 directly acts on the straight surface of the first buffer block, so that the impact force and speed of the concrete falling are reduced under the action of the straight surface of the first buffer block, and meanwhile, the concrete is guided into the buffer pipe 2.

Preferably, the angle between the straight face of the first buffer block and the centre of the transfer tube 1 is in the range 135 ° -160 °, most preferably 135 °.

Further, referring to fig. 4, the second buffer portion 4 includes a second buffer block provided on an inner wall of an upper half portion of the second pipe section 2013, the second buffer block being provided inclined from a center of the conveying pipe 1 away from an end surface not attached to the first center pipe section 2014, the second buffer block guiding concrete into the conveying pipe 1 while reducing an impact of the concrete.

Preferably, the angle between the straight face of the second buffer block and the centre of the transfer tube 1 is in the range 135 ° -160 °, most preferably 135 °.

Of course, the first buffer block and the second buffer block may be connected to the first center pipe section 2014 and the second center pipe section 2024 by welding, respectively.

Further, referring to fig. 4, a third buffer portion 5 is provided on the wall of the upper half portion of the buffer tube 2 facing the conveying tube 1, and the third buffer portion 5 is used for reducing impact of concrete on the upper half portion of the buffer tube 2 after the concrete enters the buffer tube 2.

Preferably, the third buffer part 5 comprises a wedge-shaped buffer block, the lower end of which is arranged on the inner wall of the buffer tube 2 in the direction of the first bend 201.

In this embodiment, the length of 20 meters is adopted in the single conveying pipe 1, the concrete conveyed from the conveying pipe 1 enters the first elbow pipe 201 and then impacts on the first buffer block, the falling speed of the concrete is reduced under the buffer action of the first buffer block, the concrete is poured into the buffer pipe 2 under the action of the first buffer block and then enters the second elbow pipe 202, the concrete flowing into the second elbow pipe 202 from the buffer pipe 2 impacts on the second buffer block, and the concrete is subjected to secondary deceleration, so that the falling speed of the concrete is reduced, the condition that aggregate separation occurs in the conveying process with a large height difference is avoided, meanwhile, the conveying pipes 1 are connected through the buffer pipe 2, the falling speed of the concrete is slowed down through the first buffer block and the second buffer block under the condition that the inner diameter of a conveying channel of the concrete relative to the inside of the conveying pipe 1 is not reduced, and the inside of the pipeline is prevented from being blocked in the deceleration process.

Further, referring to fig. 5 and 6, the end of the conveying pipe 1 connected with the first pipe section 2012 is provided with a first transition pipe 6, and the end of the third pipe section 2022 connected with the conveying pipe 1 is provided with a second transition pipe 7; a first countersunk groove 8 matched with the first transition pipe 6 is formed in the first pipe section 2012, and a second countersunk groove 9 matched with the second transition pipe 7 is formed in the end, connected with the third pipe section 2022, of the conveying pipe 1.

Preferably, the first transition pipe 6 and the second transition pipe 7 are formed by welding flanges welded at the ends of the conveying pipe 1 and the third pipe section 2022 on the outer wall in an upward moving manner, the first countersink 8 and the second countersink 9 are formed by reaming in the inner walls of the first pipe section 2012 and the conveying pipe 1, and the first countersink 8 and the second countersink 9 are in clearance fit with the first transition pipe 6 and the second transition pipe 7 respectively.

When the conveying pipe 1 is connected through the buffer pipe 2, one end of the conveying pipe 1, which is connected with the first pipe section 2012, is inserted into the first countersink 8 through the first transition pipe 6, and then is connected through the flange fit bolt, and when the conveying pipe 1 is connected with the fourth pipe section 2023, the second transition pipe 7 is inserted into the second countersink 9, and the connection part of the conveying pipe 1, the first bent pipe 201 and the second bent pipe 202 is tighter through the flange fit bolt, so that concrete does not overflow through the slurry of the concrete when the concrete is conveyed in the conveying pipe 1 through the connection part of the conveying pipe 1, the first bent pipe 201 and the second bent pipe 202 under the guidance of the first transition pipe 6 and the second transition pipe 7.

In an embodiment, referring to fig. 7 and 8, the outer curved wall of the second elbow 202 is provided with a convolution 10, and the convolution 10 is used for guiding the concrete to fall down after moving up and to collide with the concrete flowing out of the buffer tube 2 so as to slow down the flow rate of the concrete.

Further, the swirling part 10 includes a circular arc-shaped swirling surface, the lower end of which is connected to the third tube section 2022, and the upper end of which is connected to the fourth tube section 2023.

Preferably, the lower end of the convolute surface is below the lowest point of the end of the second central tube segment 2024 that connects to the third tube segment 2022.

In this embodiment, the concrete entering the second elbow pipe 202 through the buffer pipe 2 has a certain initial velocity, the concrete enters the second elbow pipe 202 and then impacts in the convolute plane, the concrete moves up along the convolute plane under the guidance of the convolute plane, and falls down towards the third pipe section 2022 under the action of gravity, and collides with the concrete discharged from the buffer pipe 2 in the falling process, and the falling velocity of the concrete is slowed down again.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims

1. A rotary hopper, comprising:

the conveying device comprises a conveying pipe (1), wherein a first conveying joint (101) and a second conveying joint (102) are respectively arranged at two ends of the conveying pipe (1);

the buffer tube (2), two ends of the buffer tube (2) are respectively provided with a first bent tube (201) and a second bent tube (202); the two ends of the first bent pipe (201) and the second bent pipe (202) are respectively connected with the two ends of the conveying pipe (1) so as to connect different conveying pipes (1) in parallel and in a staggered manner, and two groups of coaxially arranged pipeline structures are formed between the conveying pipes (1) positioned on the two sides of the buffer pipe (2);

the buffer assembly comprises a first buffer part (3) arranged on the central circular arc-shaped inner wall of the first bent pipe (201) and a second buffer part (4) arranged on the central circular arc-shaped inner wall of the second bent pipe (202); the first buffer part (3) and the second buffer part (4) are used for buffering the impact of the concrete conveyed in the conveying pipe (1) on the conveying pipe (1), the first elbow pipe (201) and the second elbow pipe (202).

2. A rotary hopper as claimed in claim 1 wherein: the first elbow (201) comprises a first pipe section (2012) connected to a first buffer joint (2011), a second pipe section (2013) connected to a buffer pipe (2), and a first center pipe section (2014) connecting the first pipe section (2012) and the second pipe section (2013); the inner diameter of the first pipe section (2012) is consistent with the inner diameter of the conveying pipe (1); the inner diameter of the second pipe section (2013) is consistent with the inner diameter of the buffer pipe (2); the inner diameter of the first central pipe section (2014) is larger than the inner diameters of the first pipe section (2012) and the second pipe section (2013); the second elbow (202) comprises a third pipe section (2022) connected with a second buffer joint (2021), a fourth pipe section (2023) connected with the buffer pipe (2), and a second central pipe section (2024) connecting the third pipe section (2022) and the fourth pipe section (2023); the inner diameter of the third pipe section (2022) is consistent with the inner diameter of the conveying pipe (1); the inner diameter of the fourth pipe section (2023) is consistent with the inner diameter of the buffer pipe (2); the inner diameter of the second central pipe section (2024) is larger than that of the third pipe section (2022) and the fourth pipe section (2023).

3. A rotary hopper as claimed in claim 2 wherein: the first central pipe section (2014) connected with the first pipe section (2012) and the second pipe section (2013) and the second central pipe section (2024) connected with the third pipe section (2022) and the fourth pipe section (2023) are all arc-shaped.

4. A rotary hopper according to claim 3 wherein: the inner diameter of the buffer tube (2) is consistent with the inner diameter of the first central tube section (2014), and the buffer tube (2) is obliquely arranged in a direction away from the conveying tube (1) connected with the first bent tube (201).

5. A rotary hopper as claimed in claim 4 wherein: the conveying pipes (1) on two sides of the buffer pipe (2) are arranged on two sides of the buffer pipe (2) coaxially in sequence at intervals of one buffer pipe (2).

6. A rotary hopper as claimed in claim 5 wherein: the first buffer part (3) comprises a first buffer block arranged on the inner wall of the lower half part of the first pipe section (2012); the first buffer block is arranged away from the end surface which is not attached to the first central pipe section (2014) and is inclined to the center of the conveying pipe (1), and the first buffer block guides concrete into the buffer pipe (2) while relieving the impact of the concrete; the second buffer part (4) comprises a second buffer block arranged on the inner wall of the upper half part of the second pipe section (2013); the second buffer block is arranged at the center of the conveying pipe (1) in a way of being away from the end face which is not attached to the first central pipe section (2014), and the second buffer block guides the concrete into the conveying pipe (1) while relieving the impact of the concrete.

7. A rotary hopper as claimed in claim 6 wherein: a third buffer part (5) is arranged on the pipe wall of the upper half part of the buffer pipe (2) facing the conveying pipe (1) inside; the third buffer part (5) is used for relieving impact of concrete on the upper half part of the buffer tube (2) after the concrete enters the buffer tube (2).

8. A rotary hopper as claimed in claim 7 wherein: the end head of the conveying pipe (1) connected with the first pipe section (2012) is provided with a first transition pipe (6); a second transition pipe (7) is arranged at one end of the third pipe section (2022) connected with the conveying pipe (1); a first countersunk groove (8) matched with the first transition pipe (6) is formed in the first pipe section (2012); and a second countersunk groove (9) matched with the second transition pipe (7) is formed in one end, connected with the third pipe section (2022), of the conveying pipe (1).

9. A rotary hopper as claimed in claim 1 wherein: the outer bending wall of the second bent pipe (202) is provided with a convolution part (10); the convolution part (10) is used for guiding the concrete to fall after being moved upwards to be impacted with the concrete flowing out of the buffer tube (2) so as to slow down the flow rate of the concrete.

10. A rotary hopper as claimed in claim 9 wherein: the convolution part (10) comprises a circular arc-shaped convolution surface; the lower end of the rotating surface is connected with a fourth pipe section (2023), and the upper end of the rotating surface is connected with a third pipe section (2022).