Robot for removing dust on inner wall of smoke tube of ship exhaust gas boiler

Abstract

The invention relates to the technical field of waste gas boiler smoke tube cleaning, in particular to a ship waste gas boiler smoke tube inner wall ash removal robot which comprises a side connecting frame, a smoke tube inner wall ash removal device, a smoke tube inner wall ash removal device and a smoke tube inner wall ash removal device. The driving structure is arranged between the side connecting frame and the telescopic connecting arm, and the driving structure can drive the telescopic connecting arm to deflect relative to the side connecting frame; the telescopic sleeve assembly is arranged at the end, away from the side connecting frame, of the telescopic connecting arm, the telescopic sleeve assembly is connected with a winding structure arranged on the telescopic connecting arm, and the winding structure can drive the telescopic sleeve assembly to be lengthened or shortened; the air supply pipe is detachably connected with the telescopic sleeve assembly, a switching structure is arranged on the air supply pipe, and the switching structure can change the air supply direction of the air supply pipe when the telescopic sleeve assembly is lengthened and shortened, so that compressed air acts on the cigarette ash in different directions, and the removal effect on the cigarette ash is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of waste gas boiler flue cleaning technical field, specifically a kind of ship waste gas boiler flue inner wall dust cleaning robot. BACKGROUND

[0002] Cleaning boiler flue is essential in the process of ship boiler operation, which has a positive effect on improving boiler efficiency, reducing energy consumption, prolonging boiler life, ensuring indoor air quality and reducing air pollution.

[0003] In the prior art, the cleaning of the boiler flue is mainly carried out by a brush device. Specifically, the brush device includes a motor, a transmission rod and bristles. The motor drives the bristles to move through the transmission rod, so that the bristles directly act on the inner wall of the flue to remove the dust on the inner wall of the flue, with high cleaning efficiency.

[0004] However, during the cleaning process, the dust in the flue will adhere to the brush, and the dust on the brush will be transferred to the inner wall of the flue again during the subsequent rotation of the brush, resulting in poor cleaning effect and reduced operation efficiency of the ship boiler. SUMMARY

[0005] The present application aims to provide a kind of ship waste gas boiler flue inner wall dust cleaning robot to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a kind of ship waste gas boiler flue inner wall dust cleaning robot, comprising: side connecting frame, the side connecting frame is rotatably installed with telescopic connecting arm;Drive structure is arranged between the side connecting frame and telescopic connecting arm, the drive structure can drive the telescopic connecting arm to deflect relative to the side connecting frame;Telescopic sleeve assembly is arranged at the end of the telescopic connecting arm away from the side connecting frame, the telescopic sleeve assembly is connected with the winding structure arranged on the telescopic connecting arm, and the winding structure can drive the telescopic sleeve assembly to lengthen or shorten;Air supply pipe is detachably connected with the telescopic sleeve assembly, and the air supply pipe is provided with a switching structure, which can change the air supply direction of the air supply pipe when the telescopic sleeve assembly lengthens or shortens.

[0007] The ship waste gas boiler flue inner wall dust cleaning robot as described above: the side connecting frame includes a side frame detachably mounted on the boiler manhole, and a gas pumping device is fixedly installed on the side frame, and the gas pumping device is connected with the telescopic sleeve assembly;The side connecting frame further includes a support arm installed on the side frame, and the end of the support arm away from the side frame is rotatably connected with the telescopic connecting arm.

[0008] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: the telescopic connecting arm comprises a rocker arm connected with the branch arm and a telescopic arm connected with the rocker arm, a motorized telescopic rod is fixedly installed on the rocker arm, and the action end of the motorized telescopic rod is connected with the telescopic arm; the motorized telescopic rod can drive the telescopic arm to extend along the length direction of the rocker arm.

[0009] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: the driving structure comprises a gear rotatably installed in the rocker arm and a plurality of groups of teeth circumferentially and equidistantly arranged at the end of the branch arm away from the side frame, and the gear is engaged with the teeth; the driving structure further comprises a driving device fixedly installed on the rocker arm, and the output shaft of the driving device is coaxially and fixedly connected with the gear.

[0010] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: the telescopic sleeve assembly comprises a first sleeve, a second sleeve and a third sleeve which are sequentially sleeved, the first sleeve is provided with a limiting ring adapted to abut against the telescopic arm, and the third sleeve is connected with the winding structure; the outer diameters of the first sleeve, the second sleeve and the third sleeve are sequentially reduced, the inner diameter of the first sleeve is equal to the outer diameter of the second sleeve, and the inner diameter of the second sleeve is equal to the outer diameter of the third sleeve.

[0011] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: the inner walls of the first sleeve and the second sleeve are provided with limiting grooves, and the outer sides of the top portions of the second sleeve and the third sleeve are provided with limiting blocks which can slide in the limiting grooves.

[0012] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: the winding structure comprises a winch fixedly installed on the telescopic arm and a traction cable wound on the winch, and the end of the traction cable away from the winch is fixedly connected with the third sleeve.

[0013] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: a plurality of groups of first air outlets and second air outlets which guide the interiors and exteriors thereof are circumferentially arranged on the air supply pipe, the first air outlets are obliquely downward arranged, and the second air outlets are obliquely upward arranged; the switching structure can alternately guide the first air outlets and the second air outlets.

[0014] The ship exhaust gas boiler flue inner wall dust cleaning robot as claimed in any one of the above: the switching structure comprises a blocking piece sealingly and slidingly arranged in the air supply pipe, a through hole is formed in the center of the blocking piece, and a plurality of groups of abutting rods which can penetrate the air supply pipe are arranged on the two sides of the blocking piece; the switching structure further comprises a plurality of groups of trigger pieces arranged on the third sleeve, the trigger pieces are matched with the abutting rods, and the trigger pieces can drive the blocking piece to move relative to the air supply pipe.

[0015] Compared with the prior art, the present application has the following advantages: 1. Firstly, the wind pressure acting on the inner wall of the smoke pipe can realize non-contact removal of smoke dust, avoiding the situation that the smoke dust adheres to the brush and reattaches to the inner wall of the smoke pipe when the brush is used for removal, thereby improving the removal effect of the smoke dust. Secondly, during the lifting process of the air supply pipe in the smoke pipe, the compressed air can always act on the inner wall of the smoke pipe in the movement direction of the air supply pipe, thereby realizing directional flushing of the smoke dust. Through the wind pressure action in two different directions, the smoke dust on different windward areas of the smoke pipe can be removed, thereby further improving the removal effect of the smoke dust. 2. The driving structure and the telescopic connecting arm are arranged, so that the telescopic sleeve pipe assembly can move in multiple directions on the horizontal plane, so that the telescopic sleeve pipe assembly can move to the upper side of the corresponding smoke pipe according to the cleaning needs, so that the working surface of the cleaning can cover all the smoke pipes, and effective cleaning of each group of smoke pipes can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Structure diagram of a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 2 Structure diagram of another angle of a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 3 Structure diagram of a driving structure and a telescopic connecting arm in a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 4 Structure explosion diagram of a driving structure in a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 5 Structure explosion diagram of a telescopic connecting arm in a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 6 Structure diagram of a telescopic sleeve pipe assembly and an air supply pipe in a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 7 Structure explosion diagram of a telescopic sleeve pipe assembly in a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 8 Structure explosion diagram of a switching structure in a ship exhaust gas boiler smoke pipe inner wall dust removal robot; Figure 9 Structure cross-sectional view of an air supply pipe in a ship exhaust gas boiler smoke pipe inner wall dust removal robot.

[0017] In the figure: 1, side frame; 2, air pumping device; 3, support arm; 301, tooth; 4, rocker arm; 5, driving device; 6, gear; 7, telescopic arm; 8, electric telescopic rod; 9, first sleeve; 901, limiting ring; 10, winch; 11, traction cable; 12, second sleeve; 13, third sleeve; 14, limiting groove; 15, limiting block; 16, air supply pipe; 1601, first air outlet; 1602, second air outlet; 17, plugging piece; 18, abutting rod; 19, triggering piece. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all.

[0019] Please refer to Figures 1-9 As an embodiment of the present application, the ship exhaust gas boiler flue pipe inner wall dust cleaning robot comprises a side connecting frame, a driving structure, a telescopic sleeve assembly and an air supply pipe 16.

[0020] The telescopic connecting arm is rotatably installed on the side connecting frame. Specifically, the side connecting frame comprises a side frame 1 detachably installed on a boiler manhole, the side frame 1 is fixedly installed with an air pumping device 2, and the air pumping device 2 is connected with the telescopic sleeve assembly. The side connecting frame further comprises a support arm 3 installed on the side frame 1, and the end of the support arm 3 away from the side frame 1 is rotatably connected with the telescopic connecting arm. The telescopic connecting arm comprises a rocker arm 4 rotatably connected with the support arm 3 and a telescopic arm 7 slidably connected with the rocker arm 4. The rocker arm 4 is fixedly installed with an electric telescopic rod 8, and the action end of the electric telescopic rod 8 is connected with the telescopic arm 7. The electric telescopic rod 8 can drive the telescopic arm 7 to extend along the length direction of the rocker arm 4.

[0021] In use, first, the side frame 1 is fastened on the boiler manhole by bolts. In this state, the support arm 3, the rocker arm 4 and the telescopic arm 7 are all inside the boiler. By controlling the action of the electric telescopic rod 8, the length of the rod-shaped structure formed by the rocker arm 4 and the telescopic arm 7 can be adjusted, so that the telescopic sleeve assembly can move in a circle with different radii when the rocker arm 4 moves in a circle, and the telescopic sleeve assembly can move in multiple directions in the horizontal plane, so that the telescopic sleeve assembly can be coaxial with the flue pipe to be cleaned, thereby achieving the effect of cleaning the flue pipe.

[0022] Need to explain, in the boiler is provided with a plurality of groups of smoke pipe, these smoke pipe in a row in a column set up, and the telescopic sleeve pipe assembly can move in horizontal plane multidirectional, so that the telescopic sleeve pipe assembly can move to the corresponding smoke pipe above according to the need of cleaning, so that the cleaning work surface can cover all the smoke pipe, ensure that can reach effective cleaning for each group of smoke pipe.

[0023] The driving structure is arranged between the side connecting frame and the telescopic connecting arm, the driving structure can drive the telescopic connecting arm to deflect relative to the side connecting frame, the driving structure comprises a gear 6 rotatably installed in the rocker arm 4 and a plurality of groups of teeth 301 circumferentially equidistantly arranged at one end of the branch arm 3 away from the side frame 1, the gear 6 is engaged with the teeth 301; the driving structure further comprises a driving device 5 fixedly installed on the rocker arm 4, and an output shaft of the driving device 5 is coaxially fixedly connected with the gear 6.

[0024] In the embodiment, when the driving device 5 works, the gear 6 connected therewith can rotate, and the gear 6 is in the state of being engaged with the teeth 301, so that the gear 6 can drive the rocker arm 4 to make a circumferential motion along the rotation shaft of the branch arm 3, thereby driving the rocker arm 4 to deflect, at this time, the telescopic arm 7 can be elongated or contracted relative to the rocker arm 4, so that the telescopic sleeve pipe assembly can cover all the smoke pipes, and the cleaning work surface is improved.

[0025] It also needs to be explained that the circumferential radius of the gear 6 is much smaller than that of the plurality of groups of teeth 301, that is, the rocker arm 4 only rotates a small angle in the case that the gear 6 rotates several turns, and this arrangement can effectively improve the deflection accuracy of the rocker arm 4, so that in the case that there is a rotation error of the output shaft of the existing driving device 5, the telescopic sleeve pipe assembly can maintain good coaxiality with the smoke pipe after the rocker arm 4 is deflected in place, so that the cleaning effect on the inner wall of the smoke pipe is consistent in the cleaning process.

[0026] Further, a visual detection unit is arranged in the air supply pipe 16, the visual detection unit controls the driving device 5 and the electric telescopic rod 8 to act by detecting the coaxiality of the air supply pipe 16 and the corresponding smoke pipe, so as to calibrate the position of the air supply pipe 16 and ensure the coaxiality with the smoke pipe.

[0027] Please refer to Figures 1-2 , Figure 7The telescopic sleeve assembly is arranged at the end of the telescopic connecting arm away from the side connecting frame, and is connected with a winding structure arranged on the telescopic connecting arm, and the winding structure can drive the telescopic sleeve assembly to lengthen or shorten; wherein the telescopic sleeve assembly comprises a first sleeve 9, a second sleeve 12 and a third sleeve 13 which are successively sleeved, the first sleeve 9 is provided with a limiting ring 901 which is adapted to abut against the telescopic arm 7, and the third sleeve 13 is connected with the winding structure; the outer diameters of the first sleeve 9, the second sleeve 12 and the third sleeve 13 are successively reduced, and the inner diameter of the first sleeve 9 is equal to the outer diameter of the second sleeve 12, and the inner diameter of the second sleeve 12 is equal to the outer diameter of the third sleeve 13; further, the inner walls of the first sleeve 9 and the second sleeve 12 are provided with limiting grooves 14, and the top outer sides of the second sleeve 12 and the third sleeve 13 are provided with limiting blocks 15 which can slide in the limiting grooves 14; the winding structure comprises a winch 10 fixedly installed on the telescopic arm 7 and a traction cable 11 wound on the winch 10, and the end of the traction cable 11 away from the winch 10 is fixedly connected with the third sleeve 13.

[0028] In the initial state, the traction cable 11 has an upward traction force on the third sleeve 13, so that the third sleeve 13 can be retracted into the second sleeve 12, and the second sleeve 12 can be retracted into the first sleeve 9, at this time, the tubular structure formed by the first sleeve 9, the second sleeve 12 and the third sleeve 13 is the shortest, thereby facilitating the placement of the tubular structure from the outside of the boiler manhole to the inside.

[0029] Further, the limiting block 15 can slide in the limiting groove 14, and the length of the limiting groove 14 is less than the lengths of the first sleeve 9 and the second sleeve 12, and the limiting groove 14 does not penetrate the two ends of the first sleeve 9 and the second sleeve 12, which makes the first sleeve 9 and the second sleeve 12, and the second sleeve 12 and the third sleeve 13 maintain a stable connection relationship when the limiting block 15 moves to the end of the limiting groove 14, preventing disconnection, so that when the winch 10 unwinds the traction cable 11, the third sleeve 13 can move relative to the second sleeve 12, and the second sleeve 12 can move relative to the first sleeve 9, so that the length of the tubular structure formed by the three sleeves increases.

[0030] Please refer to Figures 1-2 , Figure 6 , Figures 8-9, the third sleeve 13 is provided with an inner thread at the lower end, and the upper end of the air supply pipe 16 is provided with an outer thread, and the two are connected through the inner and outer threads; the air supply pipe 16 is provided with a switching structure, which can change the air supply direction of the air supply pipe 16 when the telescopic sleeve assembly is lengthened or shortened; a plurality of first air outlets 1601 and second air outlets 1602 are circumferentially arranged on the air supply pipe 16 to guide the inside and outside, the first air outlets 1601 are arranged obliquely downward, and the second air outlets 1602 are arranged obliquely upward; the switching structure can alternately guide the first air outlets 1601 and the second air outlets 1602; the switching structure comprises a blocking piece 17 which is sealingly and slidingly arranged in the air supply pipe 16, a through hole is formed in the center of the blocking piece 17, and a plurality of abutting rods 18 which can penetrate the air supply pipe 16 are arranged on both sides of the blocking piece 17; the switching structure further comprises a plurality of trigger pieces 19 arranged on the third sleeve 13, the trigger pieces 19 cooperate with the abutting rods 18 to drive the blocking piece 17 to move relative to the air supply pipe 16.

[0031] In the embodiment, the pump air device 2 communicates with the upper end of the first sleeve 9 through a hose, which enables the compressed gas delivered by the pump air device 2 to enter the air supply pipe 16 through the first sleeve 9, the second sleeve 12 and the third sleeve 13, and be discharged from the first air outlet 1601 or the second air outlet 1602, specifically: when the air supply pipe 16 enters the flue and moves along the length direction of the flue, at this time the blocking piece 17 is below the air supply pipe 16, so that under the action of the blocking piece 17, the second air outlet 1602 is in a blocked state, and the compressed gas can only be discharged from the first air outlet 1601, and the first air outlet 1601 is arranged obliquely downward, so that in the process of downward movement of the air supply pipe 16, the compressed gas can act obliquely downward on the inner wall of the flue, and the wind pressure is used to remove the smoke dust on the flue.

[0032] When the air supply pipe 16 moves to the lower end of the flue, the abutting rods 18 at the lower part of the blocking piece 17 will abut against the bottom wall of the flue, so that in the process of continuous downward movement of the air supply pipe 16, the blocking piece 17 can move upward relative to the air supply pipe 16, at this time the first air outlet 1601 will be blocked, and the second air outlet 1602 will be unblocked, at this time the compressed air can be discharged from the second air outlet 1602 and act obliquely upward on the inner wall of the flue, while the air supply pipe 16 moves upward, realizing the wind pressure acting on the smoke dust at another angle, and realizing the removal of the smoke dust.

[0033] When the air supply pipe 16 rises to the end of the stroke, the abutting rod 18 on the upper part of the blocking piece 17 can cooperate with the trigger 19, and the blocking piece 17 moves downward relative to the air supply pipe 16, so that the blocking piece 17 is reset, and when the air supply pipe 16 moves downward next time, the compressed air can act on the inner wall of the flue downwardly, and through the wind pressure in two different directions, the smoke dust on the flue with different windward areas can be removed, thereby improving the removal effect of the smoke dust.

[0034] It is worth noting that when the second sleeve 12 and the third sleeve 13 move downward, the downward movement force comes from the gravity of the second sleeve 12 and the third sleeve 13, which can ensure that when the abutting rod 18 abuts against the bottom wall of the flue, the blocking piece 17 can move upward, and similarly, the gravity of the first sleeve 9 can also make the blocking piece 17 move relative to the air supply pipe 16 when the abutting rod 18 acts on the trigger 19.

[0035] Based on the above arrangement, firstly, the wind pressure acting on the inner wall of the flue can realize contactless removal of the smoke dust, avoiding the situation that the smoke dust adheres to the brush and re-attaches to the inner wall of the flue when the brush is used for removal, thereby improving the removal effect of the smoke dust, and secondly, during the lifting process of the air supply pipe 16 in the flue, the compressed air can always act on the inner wall of the flue obliquely along the movement direction of the air supply pipe 16, thereby realizing directional flushing of the smoke dust, and through the wind pressure in two different directions, the smoke dust on the flue with different windward areas can be removed, thereby further improving the removal effect of the smoke dust.

[0036] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0037] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot, characterized by, The utility model relates to a boiler manhole air supply device, including: Side connecting frame, the telescopic connecting arm is rotatably installed on the side connecting frame; Driving structure, set between the side connecting frame and telescopic connecting arm, the driving structure can drive the telescopic connecting arm to deflect relative to the side connecting frame;Telescopic sleeve assembly, set in the end of the telescopic connecting arm away from the side connecting frame, the telescopic sleeve assembly is connected with the winding structure set on the telescopic connecting arm, the winding structure can drive the telescopic sleeve assembly to lengthen or shorten;Air supply pipe is detachably connected with the telescopic sleeve assembly, the air supply pipe is provided with switching structure, the switching structure can change the air supply direction of the air supply pipe when the telescopic sleeve assembly lengthens, shortens.

2. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 1, characterized in that, The side connecting frame includes a side frame detachably mounted on the boiler manhole, the side frame is fixedly installed with a pump air device, the pump air device is connected with the telescopic sleeve assembly;The side connecting frame further includes a support arm mounted on the side frame, the end of the support arm away from the side frame is rotatably connected with the telescopic connecting arm.

3. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 2, characterized in that, The telescopic connecting arm includes a rocker arm rotatably connected with the support arm and a telescopic arm slidably connected with the rocker arm, the rocker arm is fixedly installed with an electric telescopic rod, the action end of the electric telescopic rod is connected with the telescopic arm;The electric telescopic rod can drive the telescopic arm to extend along the length direction of the rocker arm.

4. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 3, characterized in that, The driving structure includes a gear rotatably installed in the rocker arm and a plurality of sets of teeth circumferentially equidistantly arranged at the end of the support arm away from the side frame, the gear is engaged with the teeth;The driving structure further includes a driving device fixedly installed on the rocker arm, the output shaft of the driving device is coaxially fixedly connected with the gear.

5. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 3, characterized in that, The telescopic sleeve assembly includes a first sleeve, a second sleeve and a third sleeve successively sleeved, the first sleeve is provided with a limiting ring abuttingly matched with the telescopic arm, the third sleeve is connected with the winding structure;The outer diameters of the first sleeve, the second sleeve and the third sleeve successively decrease, and the inner diameter of the first sleeve is equal to the outer diameter of the second sleeve, and the inner diameter of the second sleeve is equal to the outer diameter of the third sleeve.

6. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 5, characterized in that, The inner walls of the first sleeve and the second sleeve are provided with limiting grooves, and the outer sides of the top portions of the second sleeve and the third sleeve are provided with limiting blocks, which can slide in the limiting grooves.

7. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 5, characterized in that, The winding structure includes a winch fixedly installed on the telescopic arm and a traction cable wound on the winch, one end of the traction cable away from the winch is fixedly connected with the third sleeve.

8. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 1, characterized in that, A plurality of first air outlets and second air outlets are circumferentially arranged on the air supply pipe to guide the inside and outside of the air supply pipe, the first air outlets are obliquely downward arranged, and the second air outlets are obliquely upward arranged;The switching structure can alternately guide the first air outlets and the second air outlets.

9. A ship exhaust gas boiler flue gas pipe inner wall soot cleaning robot according to claim 5, characterized in that, The switching structure comprises a sealing sliding plug arranged in the air supply pipe, a through hole is formed in the center of the plug, and a plurality of groups of abutting rods capable of penetrating the air supply pipe are arranged on both sides of the plug; the switching structure further comprises a plurality of groups of trigger pieces arranged on the third sleeve, the trigger pieces are matched with the abutting rods, and the trigger pieces can drive the plug to move relative to the air supply pipe.

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