CN110725560A

CN110725560A - Grouting machine with heat preservation device

Info

Publication number: CN110725560A
Application number: CN201910990364.1A
Authority: CN
Inventors: 庞旭东; 贾君; 侯闯; 李冰; 刘金龙; 王涛; 刘加林; 呼彧; 马卫晓
Original assignee: Beijing Jinhe Water Construction Group Co Ltd
Current assignee: Beijing Jinhe Water Construction Group Co Ltd
Priority date: 2019-10-17
Filing date: 2019-10-17
Publication date: 2020-01-24

Abstract

The invention discloses a grouting machine with a heat preservation device, which comprises a fixing frame, wherein an electric control system is arranged on the fixing frame, a driving motor is arranged on the fixing frame, a conveying cavity is arranged on the fixing frame, a feeding mechanism is arranged in the conveying cavity, a feeding pipe is communicated with the conveying cavity, a discharging pipe is communicated with the conveying cavity, a high-pressure hose is communicated with the discharging pipe, a grouting head is fixedly arranged at the outlet end of the high-pressure hose, a heating system is arranged on the high-pressure hose and comprises an inner pipe sleeved on the high-pressure hose, a heating device is sleeved on the outer side of the inner pipe, and a heat preservation pipe is sleeved. The invention has the effect of prolonging the mortar solidification time in the grouting pipeline in a low-temperature environment.

Description

Grouting machine with heat preservation device

Technical Field

The invention relates to the field of mortar pouring construction equipment, in particular to a grouting machine with a heat preservation device.

Background

Grouting is a process of pumping grout into cracks or fault-broken zones of the foundation of a building or into joints or cracks of the building itself. The anti-permeability and integrity of the irrigated stratum or the building can be improved through grouting, the foundation condition is improved, and the safe operation of the hydraulic structure is ensured. The high-pressure grouting plugging is characterized in that a chemical grouting material is injected into concrete cracks by utilizing mechanical high-pressure power, and when slurry meets the water in the concrete cracks, the slurry can be rapidly dispersed, emulsified, expanded and solidified, so that all the cracks of the concrete are filled with the solidified elastomer, and water flow is completely plugged outside a concrete structure body, thereby achieving the purpose of water stopping and plugging. During grouting, a grouting machine is generally adopted for grouting, and the grouting machine is mainly used for injecting slurry in a storage tank into a construction area.

The application publication No. CN108086685A of the present invention discloses a prestressed wall grouting machine, which comprises a handle, a pulley box, wheels, a base, a motor, a transmission box and a plunger pump, wherein the handle is connected with the base, the pulley box is connected with the motor and the plunger pump, the wheels are connected with the base, the transmission box is connected with the motor, the transmission box is connected with the plunger pump, the pulley box is composed of a belt pulley, a belt and a box body, the belt pulley is connected with the belt, the belt pulley and the belt are arranged in the box body, the transmission box is provided with a coupling and a gear, the coupling is connected with the gear, the gear is connected with the belt pulley, and the plunger pump is provided with a feeding port, a discharging port, an auxiliary material.

The above prior art solutions have the following drawbacks: in winter construction, the use environment temperature of the grouting machine is reduced, mortar in a grouting pipeline of the grouting machine is reduced along with the environment temperature, the solidification time is shortened, and the grouting quality is influenced.

Disclosure of Invention

The invention aims to provide a grouting machine with a heat preservation device, which has the effect of prolonging the mortar solidification time in a grouting pipeline in a low-temperature environment.

The technical purpose of the invention is realized by the following technical scheme:

the utility model provides a take heat preservation device's slip casting machine, includes the mount, be provided with electrical system on the mount, be provided with driving motor on the mount, be provided with on the mount and carry the chamber, be provided with feeding mechanism on carrying the intracavity, the intercommunication has the inlet pipe on carrying the chamber, and the intercommunication has the discharging pipe on carrying the chamber, and the intercommunication has high-pressure hose on the discharging pipe, and high-pressure hose exit end has set firmly the slip casting head, be provided with heating system on the high-pressure hose, heating system locates the inner tube on the high-pressure hose including the cover, and the inner tube outside cover is equipped with heating device.

By adopting the technical scheme, the driving motor is controlled to operate in the electric control system, the driving motor drives the feeding mechanism to operate, the feeding mechanism pressurizes materials in the conveying cavity to enable mortar in the conveying cavity to enter the discharging pipe, the mortar in the discharging pipe flows into the high-pressure hose, the materials in the high-pressure hose flow out through the grouting head, when the heating system is used for heating the high-pressure hose, heat generated by the heating device is transmitted to the high-pressure hose through the inner pipe to heat the high-pressure hose, the heat preservation pipe can reduce waste of heat generated by the heating wire, therefore, when winter construction is guaranteed, the temperature of the mortar in the high-pressure hose is kept, and the mortar solidification time in the high-.

The invention is further configured to: the heating device comprises an electric heating wire laid on the outer side of the inner pipe, and the electric heating wire is electrically connected with an electric control system.

By adopting the technical scheme, the electric control system controls the current in the heating wire, the heating wire generates heat to heat the inner tube, and the inner tube heats the high-pressure hose.

The invention is further configured to: the heating device comprises a combustion chamber, a heating ring positioned between an inner pipe and a heat preservation pipe is communicated with the combustion chamber, an exhaust pipe is communicated with the heating ring, a fuel box is arranged in the combustion chamber, and hot air generated after fuel in the fuel box is combusted in the combustion chamber enters the heating ring.

Through adopting above-mentioned technical scheme, the steam that produces after the combustion chamber is burnt gets into the heating ring, and the heating ring heats the inner tube, and the inner tube heats high-pressure hose, and the intra-annular waste gas of heating discharges through the exhaust pipe, realizes heating device to the heating of inner tube.

The invention is further configured to: a heat conduction ring is arranged between the heating ring and the inner pipe, heat storage liquid is arranged in the heat conduction ring, a steam pipe is communicated with the heat conduction ring, and an exhaust valve is communicated with the steam pipe;

the heat conduction pipe is communicated with a water feeding pipe for injecting heat storage liquid into the heat conduction ring, and the water feeding pipe is detachably connected with a plug cover for tightly sealing the pipe orifice.

By adopting the technical scheme, the heat storage liquid in the heat conduction ring can limit the highest temperature of the heat conduction ring, the high-pressure hose is prevented from being damaged due to overhigh temperature of the heat conduction ring, the air pressure in the heat conduction ring is increased after the heat storage liquid in the heat conduction ring is evaporated, the exhaust valve is opened when the pressure in the heat conduction ring is greater than the opening pressure of the exhaust valve, so that the pressure in the heat conduction ring is reduced, the volume of clean water in the heat conduction ring can be judged by observing the water adding pipe, and when the volume of water in the heat conduction ring is small, the plug cover is opened to add clean water.

The invention is further configured to: the communicating pipe is communicated with a liquefaction ring which is positioned outside the combustion chamber.

Through adopting above-mentioned technical scheme, the combustion chamber is close to the one end temperature of inlet port lower, and the liquefaction ring is located the one end that the combustion chamber is close to the inlet port and can reduces the intra-annular temperature of liquefaction, avoids the intra-annular high temperature of heat conduction to produce the heat-retaining liquid of steam fast consumption in the heat conduction ring.

The invention is further configured to: the heating devices are arranged in a plurality at intervals along the length direction of the high-pressure hose.

Through adopting above-mentioned technical scheme, different service environment temperature uses the heating device of different quantity to heat high-pressure hose, ensures the slip casting head output stable temperature's of slip casting machine mortar.

The invention is further configured to: the outer side of the heat-insulating pipe is hinged with at least three supporting legs for supporting the heat-insulating pipe.

Through adopting above-mentioned technical scheme, the landing leg is used for supporting the insulating tube, keeps the stability of insulating tube, makes partial high pressure hose keep away from ground simultaneously, reduces high pressure hose's calorific loss.

The invention is further configured to: the insulating tube has set firmly the elastic ring on high-pressure hose length direction's both ends respectively, and the elastic ring is round platform shape casing, and the main aspects and the insulating tube fixed connection of elastic ring, the one end of elastic ring have been seted up a plurality of and have been provided with the groove of stepping down along elastic ring circumference interval, and the tip internal diameter of elastic ring equals the internal diameter of high-pressure hose.

By adopting the technical scheme, when mortar is injected into the high-pressure hose, the actual outer diameter of the high-pressure hose is smaller than the inner diameter of the elastic ring, the high-pressure hose can freely pass through the heating device, when the mortar is injected into the high-pressure hose, the high-pressure hose extrudes the elastic ring, the elastic ring compresses the high-pressure hose while deforming, and the stable connection between the high-pressure hose and the heating device is kept.

The invention is further configured to: the combustion chamber is characterized in that an air inlet is formed in one end of the combustion chamber, a fixed disc is embedded in the air inlet, fixing holes are formed in the end face of the fixed disc and are evenly distributed along the circumferential direction of the fixed disc at intervals, a rotating disc rotating around the central line of the air inlet is embedded in the air inlet, and a rotating hole corresponding to the fixing hole is formed in the end face of the rotating disc.

Through adopting above-mentioned technical scheme, can realize rotating the mistake mutually of hole and fixed orifices with the rolling disc rotation, can adjust the actual aperture size of combustion chamber inlet port when rotating through the rolling disc to the burning rate of fuel in the adjustment combustion chamber, control heating efficiency.

In conclusion, the beneficial effects of the invention are as follows:

1. the driving motor is controlled to operate in the electric control system, the driving motor drives the feeding mechanism to operate, the feeding mechanism pressurizes materials in the conveying cavity to enable the mortar in the conveying cavity to enter the discharge pipe, the mortar in the discharge pipe flows into the high-pressure hose, the materials in the high-pressure hose flow out through the grouting head, when the heating system is used for heating the high-pressure hose, heat generated by the heating device is transferred to the high-pressure hose through the inner pipe to heat the high-pressure hose, the heat preservation pipe can reduce waste of heat generated by the electric heating wire, therefore, the temperature of the mortar in the high-pressure hose can be guaranteed during winter construction, and the mortar solidification time in the high-;

2. the electric control system controls the current in the electric heating wire, the electric heating wire generates heat to heat the inner pipe, and the inner pipe heats the high-pressure hose;

3. the hot gas that produces after the combustion chamber is burnt gets into the heating ring, and the heating ring heats the inner tube, and the inner tube heats high-pressure hose, and the intra-annular waste gas of heating discharges through the waste gas pipe, realizes heating device to the heating of inner tube.

Drawings

FIG. 1 is a schematic overall structure diagram of the first embodiment;

FIG. 2 is a schematic cross-sectional view of a medium-high pressure hose and a heating device according to an embodiment;

FIG. 3 is a schematic view showing the structure of a heating apparatus according to a second embodiment;

FIG. 4 is a schematic cross-sectional view of a heating apparatus according to a second embodiment.

In the figure, 11, a fixed frame; 12. an electronic control system; 13. a drive motor; 14. a delivery lumen; 15. a feeding mechanism; 16. a feed pipe; 17. a discharge pipe; 2. a high pressure hose; 3. a heating device; 31. an electric heating wire; 32. a combustion chamber; 33. a heating ring; 34. an exhaust gas pipe; 35. a fuel cartridge; 36. fixing the disc; 37. rotating the disc; 41. an inner tube; 42. a heat preservation pipe; 5. a heat conducting ring; 52. a steam pipe; 53. an exhaust valve; 54. a communicating pipe; 55. a liquefaction ring; 56. a water feeding pipe; 57. a plug cover; 6. an elastic ring; 61. a yielding groove; 7. and (4) grouting heads.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example one

Referring to fig. 1, the invention discloses a grouting machine with a heat preservation device, which comprises a fixed frame 11, wherein four rollers are arranged on the ground of the fixed frame 11, and the rollers are convenient for the grouting machine to move.

The fixed frame 11 is fixedly provided with a conveying cavity 14, the conveying cavity 14 is communicated with a feeding pipe 16 for feeding mortar into the conveying cavity 14, the conveying cavity 14 is communicated with a discharging pipe 17, and the mortar in the conveying cavity 14 flows out through the discharging pipe 17.

The conveying cavity 14 is internally provided with a feeding mechanism 15, the feeding mechanism 15 pressurizes materials in the conveying cavity 14 to enable mortar materials to be extruded out of the conveying cavity 14 through a discharge pipe 17, the fixing frame 11 is provided with a driving motor 13, and the driving motor 13 drives the feeding mechanism 15 to operate through chain transmission, so that the feeding mechanism 15 pressurizes the mortar materials in the conveying cavity 14. An electric control system 12 for controlling a driving motor 13 is arranged on the fixing frame 11, and the electric control system 12 controls the opening and closing of the grouting machine and the conveying speed of the mortar.

The discharge pipe 17 is fixedly connected with a high-pressure hose 2 through a hoop, and the outlet end of the high-pressure hose 2, which is back to the discharge pipe 17, is fixedly provided with a grouting head 7.

Referring to fig. 1 and 2, a heating system is disposed on the high-pressure hose 2, the heating system includes an inner tube 41 sleeved on the high-pressure hose 2, a heating device 3 is sleeved outside the inner tube 41, the heating device 3 is a heating wire 31 laid outside the inner tube 41, the heating wire 31 is electrically connected to the electronic control system 12, the electronic control system 12 supplies electric energy to the heating wire 31 to heat the heating wire 31, and a heat preservation tube 42 is sleeved outside the heating device 3.

The implementation principle of the above embodiment is as follows:

the driving motor 13 is controlled to operate in the electric control system 12, the driving motor 13 drives the feeding mechanism 15 to operate, the feeding mechanism 15 pressurizes materials in the conveying cavity 14 to enable mortar in the conveying cavity 14 to enter the discharge pipe 17, the mortar in the discharge pipe 17 flows into the high-pressure hose 2, the materials in the high-pressure hose 2 flow out through the grouting head 7, when the heating system is used for heating the high-pressure hose 2, the electric heating wires 31 are turned on through the electric control system 12, the electric heating wires 31 generate heat, the heat generated by the electric heating wires 31 is transmitted to the high-pressure hose 2 through the inner pipe 41 to heat the high-pressure hose 2, the heat insulation pipe 42 can reduce waste of the heat generated by the electric heating wires 31, accordingly, the temperature of the mortar in the high-pressure hose 2 is guaranteed during winter construction.

Example two

Referring to fig. 3 and 4, a grouting machine with a thermal insulation device is different from embodiment 1 in that a heating device 3 includes a combustion chamber 32, a fuel cartridge 35 is disposed in the combustion chamber 32, and a fuel, which is fuel oil in this embodiment, or paraffin, is disposed in the fuel cartridge 35, and the fuel in the fuel cartridge 35 can enter a hot air flow generated by combustion in the combustion chamber 32.

The combustion chamber 32 is a cylinder with an opening at one end, the opening of the combustion chamber 32 is an air inlet, a fixed disk 36 is embedded in the air inlet, the fixed disk 36 is in compression connection with the side surface of the combustion chamber 32, fixing holes which are uniformly distributed along the circumferential direction of the fixed disk 36 are formed in the end surface of the fixed disk 36, the fixing holes are square holes which are radially arranged along the fixed disk 36 in length, and twelve fixing holes are uniformly distributed along the circumferential direction of the fixed disk 36 at intervals by taking the axis of the fixed disk 36 as a central line. The air inlet is embedded with a rotating disc 37 rotating around the central line of the air inlet, the end face of the rotating disc 37 facing the bottom surface of the combustion chamber 32 is in contact with the end face of the fixed disc 36, the end face of the rotating disc 37 is provided with a rotating hole corresponding to the fixed hole, the rotating disc 37 is rotated for 5 degrees around the central line of the air inlet, the rotating hole and the fixed hole can be staggered, the effective aperture size of the air inlet of the combustion chamber 32 can be adjusted when the rotating disc 37 rotates, and therefore the combustion speed can be adjusted.

The combustion chamber 32 is communicated with a heating ring 33 sleeved outside the inner pipe 41, a round pipe communicated with the inner cavity of the combustion chamber 32 is fixed on the side surface of the combustion chamber 32, and the round pipe realizes the communication between the combustion chamber 32 and the inner cavity of the heating ring 33. The heating ring 33 comprises an inner ring and an outer ring, two ends of the heating ring 33 are closed, and a closed cavity is formed between the inner ring and the outer ring. An exhaust gas pipe 34 is connected to the heating ring 33, and exhaust gas in the heating ring 33 is discharged through the exhaust gas pipe 34.

The heat conduction ring 5 is arranged between the heating ring 33 and the inner pipe 41, the heat conduction ring 5 is a hollow circular shell with the same structure as the heating ring 33, heat storage liquid is arranged in the heat conduction ring 5, the heat storage liquid is water or saline water in the embodiment, the heat conduction ring 5 is communicated with a steam pipe 52, the steam pipe 52 is communicated with an exhaust valve 53, and when a pressure cavity in the heat conduction ring 5 exceeds the opening pressure of the exhaust valve 53, the exhaust valve 53 is opened, so that the pressure cavity in the heat conduction ring 5 is reduced.

The side of the heat conduction ring 5 is fixedly provided with a communicating pipe 54 communicated with the inner cavity of the heat conduction ring, the communicating pipe 54 is communicated with a liquefaction ring 55, the liquefaction ring 55 is a circular ring with the same structure as the heating ring 33, and the liquefaction ring 55 is sleeved outside the combustion chamber 32.

Set firmly on the liquefaction ring 55 with its inner chamber intercommunication to inject the filler pipe 56 of clear water into heat conduction ring 5, filler pipe 56 uses transparent high temperature resistant polytetrafluoroethylene to be the pipe that the material was made, and when heating device 3 used, the interface that filler pipe 56 and liquefaction ring 55 are connected was located the liquefaction ring 55 side and is close to the part on ground, and the axis of filler pipe 56 is along vertical direction, can judge the water level in the heat conduction ring 5 through observing the water level height of filler pipe 56. A plug 57 for sealing the nozzle is detachably connected to the water feed pipe 56.

The square casing in the heating device 3 outside is located for the cover to the insulating tube 42, and the insulating tube 42 uses high temperature resistance rock wool board to support, and rock wool board outside parcel has metal fixing plate to support the rock wool board. The heat preservation pipe 42 is provided with a round hole for the high-pressure hose 2 to pass through, a yielding hole corresponding to the air inlet hole, and a notch for the exhaust gas pipe 34 and the exhaust valve 53 to extend out of the air outlet.

The outer side of the heat preservation pipe 42 is hinged with four supporting legs for supporting the heat preservation pipe 42, the four supporting legs rotate 120 degrees around the hinged shafts of the four supporting legs and the heat preservation pipe 42, the supporting legs at the opposite end angles of the heat preservation pipe 42 rotate back to back, supporting of the supporting legs on the heat preservation pipe 42 is achieved, a gap is formed between the high-pressure hose 2 and the ground, and heat loss of the high-pressure hose 2 is reduced.

The insulating tube 42 has set firmly elastic ring 6 respectively along 2 length direction's of high pressure hose both ends, and elastic ring 6 is round platform shape casing, and elastic ring 6's main aspects and insulating tube 42 fixed connection, elastic ring 6's one end have been seted up a plurality ofly and have been provided with along 6 circumference intervals of elastic ring and step down groove 61, and the degree of depth in groove 61 of stepping down equals the ten of 6 axis length of elastic ring, and elastic ring 6's tip internal diameter equals high pressure hose 2's internal diameter. When mortar is injected into the high-pressure hose 2, the actual outer diameter of the high-pressure hose 2 is smaller than the inner diameter of the elastic ring 6, the high-pressure hose 2 can freely pass through the heating device 3, when the mortar is injected into the high-pressure hose 2, the elastic ring 6 is extruded by the high-pressure hose 2, the high-pressure hose 2 is pressed while the elastic ring 6 deforms, and the stable connection between the high-pressure hose 2 and the heating device 3 is kept.

The heating device 3 is provided with a plurality of different service environment temperatures along the length direction of the high-pressure hose 2, and the heating device 3 with different quantities is used for heating the high-pressure hose 2.

The implementation principle of the above embodiment is as follows:

the fuel enters the heating ring 33 after being combusted in the combustion chamber 32, hot air in the heating ring 33 heats the heat conduction ring 5, the heat conduction ring 5 heats the inner pipe 41, the inner pipe 41 heats the high-pressure hose 2, water in the heat conduction ring 5 can enable the highest temperature of the heat conduction ring 5 to be 100 ℃, damage to the high-pressure hose 2 caused by overhigh temperature of the heat conduction ring 5 is avoided, air pressure in the heat conduction ring 5 is increased after water in the heat conduction ring 5 is evaporated, when the pressure in the heat conduction ring 5 is higher than the opening pressure of the exhaust valve 53, the exhaust valve 53 is opened, so that the pressure in the heat conduction ring 5 is reduced, partial liquid in the heat conduction ring 5 enters the liquefaction ring 55, the temperature of one end, close to an air inlet, of the liquefaction ring 55 is lower, the temperature of one end, opposite to the air inlet, of the liquefaction ring 55 is higher, convection is formed, the temperatures in each liquefaction ring 55 and the heat conduction ring 5 are kept relatively stable, the clear, when the volume of water in the heat conduction ring 5 is small, the plug cover 57 is opened to add clean water into the water adding pipe 56.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. The utility model provides a take heat preservation device's slip casting machine, including mount (11), be provided with electrical system (12) on mount (11), be provided with driving motor (13) on mount (11), be provided with on mount (11) and carry chamber (14), be provided with feeding mechanism (15) in carrying chamber (14), the intercommunication has inlet pipe (16) on carrying chamber (14), the intercommunication has discharging pipe (17) on carrying chamber (14), the intercommunication has high-pressure hose (2) on discharging pipe (17), high-pressure hose (2) exit end has set firmly slip casting head (7), its characterized in that: the high-pressure hose (2) is provided with a heating system, the heating system comprises an inner tube (41) sleeved on the high-pressure hose (2), a heating device (3) is sleeved outside the inner tube (41), and a heat preservation tube (42) is sleeved outside the heating device (3).

2. The grouting machine with the heat preservation device according to claim 1, characterized in that: the heating device (3) comprises an electric heating wire (31) laid on the outer side of the inner pipe (41), and the electric heating wire (31) is electrically connected with the electric control system (12).

3. The grouting machine with the heat preservation device according to claim 1, characterized in that: the heating device (3) comprises a combustion chamber (32), a heating ring (33) positioned between an inner pipe (41) and a heat preservation pipe (42) is communicated with the combustion chamber (32), an exhaust pipe (34) is communicated with the heating ring (33), a fuel box (35) is arranged in the combustion chamber (32), and hot air generated after fuel in the fuel box (35) is combusted in the combustion chamber (32) enters the heating ring (33).

4. The grouting machine with a heat preservation device according to claim 3, characterized in that: a heat conduction ring (5) is arranged between the heating ring (33) and the inner pipe (41), heat storage liquid is arranged in the heat conduction ring (5), a steam pipe (52) is communicated with the heat conduction ring (5), and an exhaust valve (53) is communicated with the steam pipe (52);

the heat conduction pipe is communicated with a water feeding pipe (56) which injects heat storage liquid into the heat conduction ring (5), and the water feeding pipe (56) is detachably connected with a plug cover (57) which seals the pipe orifice.

5. The grouting machine with a heat preservation device according to claim 4, characterized in that: the communicating pipe (54) is communicated with a liquefaction ring (55), and the liquefaction ring (55) is positioned outside the combustion chamber (32).

6. The grouting machine with the heat preservation device according to claim 2, characterized in that: the heating devices (3) are arranged in a plurality at intervals along the length direction of the high-pressure hose (2).

7. The grouting machine with the heat preservation device according to claim 2, characterized in that: the outer side of the heat preservation pipe (42) is hinged with at least three supporting legs for supporting the heat preservation pipe (42).

8. The grouting machine with the heat preservation device according to claim 2, characterized in that: insulating tube (42) are followed high-pressure hose (2) length direction's both ends and are set firmly elasticity ring (6) respectively, and elasticity ring (6) are round platform shape casing, the main aspects and insulating tube (42) fixed connection of elasticity ring (6), and a plurality of edges elasticity ring (6) circumference interval are provided with and step down groove (61) have been seted up to the one end of elasticity ring (6), and the tip internal diameter of elasticity ring (6) equals the internal diameter of high-pressure hose (2).

9. The grouting machine with the heat preservation device according to claim 2, characterized in that: the combustion chamber is characterized in that an air inlet is formed in one end of the combustion chamber (32), a fixed disc (36) is embedded in the air inlet, fixing holes are formed in the end face of the fixed disc (36) and are uniformly distributed at intervals along the circumferential direction of the fixed disc (36), a rotating disc (37) rotating around the central line of the air inlet is embedded in the air inlet, and a rotating hole corresponding to the fixing hole is formed in the end face of the rotating disc (37).