Tail gas purification treatment device for pyrrole nitrile bromination reaction

Abstract

The utility model relates to a tail gas purification treatment device for pyrrole nitrile bromination reaction. The main body of the device is a tank body, and spraying equipment and a filler layer are arranged in the tank body to realize basic purification of waste gas. Different from the prior art, a partition plate is arranged on the lower side of the tank body, and the air inlet pipe is lower than the partition plate. The gas outlet pipes are specially arranged on the partition plate, so that the waste gas is in a dispersed state on the lower side of the filler layer, and the gas outlet pipes are trapezoidal structures, so that the power and dispersion range of the waste gas are enhanced. Through the structural design, the contact time of the waste gas and the purification liquid is prolonged, the waste gas treatment effect is remarkably improved, and the tail gas generated by the pyrrole nitrile bromination reaction is effectively purified.

Description

Technical Field

[0001] This utility model relates to the technical field of waste gas treatment devices, and in particular to a tail gas purification and treatment device for pyrrolidone bromination reaction. Background Technology

[0002] During the bromination of pyrrolidone, the composition of the exhaust gas varies with the different stages of the reaction, thus requiring adjustments to the treatment methods based on specific circumstances. The exhaust gas from the chlorination addition reaction is treated using a two-stage alkaline scrubbing system combined with activated carbon adsorption-desorption condensation and recovery. The exhaust gas from the elimination reaction is first treated with a primary water cooling system followed by a primary cryogenic brine system, and then further treated using the aforementioned system. The exhaust gas from the distillation process of the chlorination reaction is treated using a primary water cooling system followed by a primary cryogenic brine system combined with activated carbon adsorption-desorption condensation and recovery.

[0003] The "two-stage alkaline spray + activated carbon adsorption-desorption condensation recovery device" is a commonly used combination equipment for waste gas treatment. Its working principle is to first use two-stage alkaline spray to neutralize acidic gases in the tail gas, such as hydrogen chloride and sulfuric acid mist. Then, the pre-treated tail gas is pressurized by the action of the fan and enters the activated carbon adsorber to adsorb the organic pollutants therein.

[0004] Currently, most treatment devices for chlorination addition reaction waste gas consist of a tank, a spray system, an inlet pipe, and a packing layer. The tank serves as the main containment space, with the spray system located at the top to spray the purifying liquid into initial contact with the waste gas. The inlet pipe introduces the waste gas, while the packing layer comprises positioning plates and packing material. The through holes in the positioning plates allow the waste gas and purifying liquid to pass through, achieving gas-liquid contact and thus promoting the purification process.

[0005] However, these traditional devices have significant drawbacks. After the exhaust gas enters the tank, the lack of effective guidance leads to uneven distribution of the exhaust gas within the packing layer. In some areas, the exhaust gas flows through rapidly, while in other areas, the flow is insufficient, thus reducing the actual utilization rate of the packing layer. Furthermore, the contact effect between the exhaust gas and the purification liquid is poor, with limited contact time and area, resulting in a high concentration of harmful substances remaining in the purified exhaust gas.

[0006] In summary, existing equipment has shortcomings in terms of processing efficiency and purification effect, and there is an urgent need for new equipment to solve these problems in order to achieve efficient and stable waste gas purification treatment and meet the growing environmental protection needs of the chemical industry. Utility Model Content

[0007] To address the shortcomings of existing technologies, this invention proposes a pyrrolidone bromination reaction tail gas purification and treatment device. This device ensures efficient and effective waste gas treatment, solving the problem of existing devices' inability to achieve precise control during waste gas treatment. Specifically, current devices suffer from the following issue: some waste gas remains in the tank for too long, while other waste gas has too short a contact time with the purification liquid, directly leading to unsatisfactory purification results.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A tail gas purification and treatment device for the bromination reaction of pyrrolonitrile includes a tank body with a packing layer inside. A spraying device is located at the upper end of the tank body. A partition plate is also included on the lower side of the tank body. Multiple outlet pipes are connected through the partition plate and are evenly distributed around the central axis of the partition plate. The angle between the central axis of each outlet pipe and the central axis of the partition plate is less than 90 degrees. The projection of each outlet pipe onto a vertical plane is trapezoidal. The inner diameter of the lower end of each outlet pipe is larger than the inner diameter of its upper end. The intersection of the central axes of the multiple outlet pipes coincides with the central axis of the partition plate, and this intersection is located below the packing layer. An inlet pipe is connected to the lower side of the tank body. The waste gas generated by the chlorination addition reaction enters the tank body through this inlet pipe, and the height of the inlet pipe is lower than the height of the partition plate.

[0010] Preferably, the upper end of the partition plate is rotatably connected to a driven shaft arranged along the vertical axis, and a plurality of driven blades are fixedly connected to the driven shaft. The lower end of the partition plate is drivenly connected to a drive shaft arranged along the vertical axis. The drive shaft is drivenly connected to the driven shaft, and a plurality of drive blades are fixedly connected to the side end of the drive shaft.

[0011] Preferably, there is an angle between the vertical centerline of the driven blade and the centerline of the driven shaft, the driven blade is used to drive the airflow upward, and the driven blade is located between the intersection of the centerlines of multiple outlet pipes and the packing layer.

[0012] Preferably, the filler layer includes two positioning plates arranged one above the other, with filler filling between the two positioning plates, and each positioning plate has multiple through holes.

[0013] Preferably, a follower shaft is provided between the two positioning plates. Multiple follower blades are fixedly connected to the side end of the follower shaft. The follower blades are on the same horizontal plane as the packing. The follower shaft and the driven shaft are connected by a reduction mechanism. The rotational speed of the follower shaft is less than that of the driven shaft.

[0014] Preferably, a guide tube with an inverted L-shaped structure in the vertical plane projection is fixedly connected in the lower inner cavity of the tank body. The vertical section of the guide tube is connected to the air intake pipe, and the horizontal section of the guide tube faces the drive blade.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. Design of partition plate and vent pipe:

[0017] Waste gas entry and pre-distribution: The partition plate on the lower side of the tank and the air inlet pipe below the partition plate cause the waste gas to first accumulate in the space on the lower side of the tank, avoiding impact on the upper treatment area and creating conditions for orderly treatment of waste gas.

[0018] Waste gas confinement and dispersion distribution: The specially arranged exhaust pipes on the partition plate have an angle of less than 90 degrees with the central axis of the partition plate, and the intersection point coincides with the central axis of the partition plate on the lower side of the packing layer. After multiple exhaust gases are discharged through the exhaust pipes, they collide with each other, canceling the upward force, so that the exhaust gases are in a dispersed state on the lower side of the packing layer, avoiding rapid passage through the packing layer, ensuring full contact with the packing layer and purification liquid, and improving the removal rate of harmful substances in the exhaust gas.

[0019] 2. The function of the trapezoidal air outlet pipe:

[0020] The exhaust pipe projects in a trapezoidal shape in the vertical plane, with the lower inner diameter larger than the upper diameter. This trapezoidal structure effectively guides the exhaust gas, ensuring it has sufficient upward force and maintains a large horizontal force after impact. This expands the dispersion range of the exhaust gas under the packing layer, allowing for more thorough contact between the exhaust gas and the purification liquid and packing material. Consequently, it enhances the depth and effectiveness of exhaust gas treatment, significantly reducing the pollutant content in the exhaust gas. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0022] Figure 2 This is a schematic diagram showing the positional relationship between the drive shaft and the driven shaft of this utility model.

[0023] Figure 3 This is a schematic diagram showing the connection between the guide tube and the intake pipe of this utility model.

[0024] Figure 4 This is a schematic diagram showing the connection relationship between the follower shaft and the positioning plate of this utility model.

[0025] Figure 5 This is a schematic diagram showing the positional relationship between the follower shaft and the reduction mechanism of this utility model.

[0026] Figure 6 This is a schematic diagram showing the connection relationship between the follower shaft and the reduction mechanism of this utility model.

[0027] In the diagram: 1. Tank body; 2. Packing layer; 201. Positioning plate; 202. Packing; 203. Through hole; 204. Follower shaft; 205. Follower blade; 3. Divider plate; 4. Air inlet pipe; 5. Driven blade; 6. Driven shaft; 7. Air outlet pipe; 8. Drive blade; 9. Drive shaft; 10. Guide pipe; 11. Spraying equipment; 12. Reduction mechanism. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] Please see Figure 1 This utility model relates to a device for purifying and treating the tail gas of a pyrrolidone bromination reaction. Its structure is similar to that of existing devices, mainly consisting of a tank 1. The tank 1 is the core of the device, providing ample space for waste gas purification.

[0031] Specifically, a spray device is installed at the upper end of tank 1. This device, through its efficient working principle, can spray a purification liquid into the interior of tank 1. The purification liquid and the exhaust gas are fully mixed in counter-current contact, removing pollutants from the exhaust gas through chemical reaction or physical adsorption. Optimization of spray volume and spray pressure, as well as the selection of spray liquid, work together to improve the purification efficiency of the exhaust gas.

[0032] Therefore, this device has an inlet pipe 4 connected to the lower side of the tank 1, through which the waste gas generated by the chlorination addition reaction enters the tank 1. The design and location of the inlet pipe 4 are crucial to ensure that the waste gas enters the device smoothly and improves operating efficiency.

[0033] Furthermore, a packing layer 2 is installed inside the tank 1. This packing layer 2 plays a crucial role in purifying the waste gas by providing a larger contact area, adsorption, absorption, chemical reaction, and biodegradation. Specifically, the packing layer 2 includes two vertically arranged positioning plates 201, with packing 202 filling the space between the two positioning plates 201. Each positioning plate 201 has multiple through holes 203, which allow the waste gas and purified liquid to pass smoothly through the packing layer 2. The purpose of the packing layer 2 is to increase the contact area between the waste gas and the purified liquid, thereby improving the purification efficiency.

[0034] Therefore, in actual operation, the spraying device evenly sprays the purification liquid onto the upper positioning plate 201. The purification liquid then slowly seeps downwards under gravity, making full contact with the packing material 202. Simultaneously, the exhaust gas moves upwards through the through-holes 203 on the lower positioning plate 201 and contacts the packing material 202. During this process, both the exhaust gas and the purification liquid come into contact with the packing material 202 simultaneously, ensuring a relatively long contact time between them, thereby guaranteeing the effective treatment of the exhaust gas by the purification liquid. This design ensures that pollutants in the exhaust gas can be fully absorbed and removed.

[0035] It is worth noting that packing 202, as the core of packing layer 2, has a significant impact on the gas-liquid mass transfer effect. An ideal packing 202 should possess a large specific surface area and a high mass transfer rate to promote gas-liquid contact and mass transfer efficiency. Good wetting properties and characteristics that facilitate uniform gas-liquid distribution ensure the efficient use of packing 202. Furthermore, packing 202 should have good porosity and gas-liquid permeability to reduce airflow resistance, while also possessing high mechanical strength, corrosion resistance, ease of cleaning, and resistance to breakage. Common packing 202 types include 50mm multifaceted hollow spheres.

[0036] Meanwhile, in practical applications, the use of high-efficiency packing materials such as metal Pall rings (202) can significantly improve the efficiency and purification effect of waste gas treatment. These packing materials (202) not only possess excellent corrosion resistance and high-temperature resistance, but also increase the gas-liquid contact area through their unique structural design, thereby effectively adsorbing and reacting harmful substances in the waste gas. For example, certain specific packing material (202) can effectively adsorb specific harmful gases or promote certain chemical reactions, thereby further improving purification efficiency.

[0037] Please see Figure 2 , Figure 3 Unlike existing devices, this device has a partition plate 3 on the lower side of the tank 1, which effectively separates the lower space from the upper space of the tank 1. The purpose of this design is to better control the flow path of the exhaust gas within the device, ensuring that the exhaust gas can be purified along a predetermined route.

[0038] It is worth noting that the intake pipe 4 is positioned lower than the partition plate 3, ensuring that the exhaust gas enters the lower space first after entering the tank 1.

[0039] Therefore, this device has multiple exhaust pipes 7 on the partition plate 3, which are evenly distributed around the central axis of the partition plate 3. Furthermore, the angle between the central axis of each exhaust pipe 7 and the central axis of the partition plate 3 is less than 90 degrees. This design ensures that the main function of the exhaust pipes 7 is to connect the upper and lower spaces of the tank 1 and restrict the movement of exhaust gas to the upper space. In this way, the flow of exhaust gas within the device can be effectively controlled, ensuring that the exhaust gas is dispersed below the packing layer 2.

[0040] In practical applications, this device adjusts the intersection of the central axes of multiple outlet pipes 7 to coincide with the central axis of the partition plate 3, and the intersection of the central axes of multiple outlet pipes 7 is located below the packing layer 2. Through the unique structural design of the outlet pipes 7, the upward force of the exhaust gas after multiple collisions is effectively counteracted. This design ensures that the exhaust gas flows upward in a specific manner, and after entering the lower side of the tank 1, it is in a diffused state, preventing the exhaust gas from passing through the packing layer 2 quickly, thereby prolonging the contact time between the exhaust gas and the packing layer 2 and the purification liquid sprayed by the spraying device. In addition, the design of the outlet pipes 7 also ensures that the flow path and speed of the exhaust gas in the device are precisely controlled, further improving the purification efficiency.

[0041] Furthermore, this device specifies that the vertical projection of each outlet pipe 7 is trapezoidal, and the inner diameter of the lower end of each outlet pipe 7 is larger than the inner diameter of its upper end. This design ensures that the exhaust gas can be constricted, giving it sufficient upward momentum and ensuring that after multiple exhaust gas streams collide, they still retain a large horizontal force, thereby ensuring the dispersion range of the exhaust gas below the packing layer 2. This design not only improves the contact efficiency between the exhaust gas and the purification liquid but also ensures the uniform distribution of the exhaust gas within the device.

[0042] Furthermore, to prevent the exhaust gas from sinking and backflowing due to lack of upward momentum, this device has a driven shaft 6 at the upper end of the partition plate 3, which is connected to the vertical axial rotation. Multiple driven blades 5 are fixedly installed on the driven shaft 6. The design of the driven blades 5 cleverly utilizes mechanical principles to apply an upward thrust to the exhaust gas, ensuring that the upward speed of the exhaust gas can be precisely controlled by the operator. This ensures that the contact time between the exhaust gas and the purification liquid is up to standard, ultimately achieving the optimal purification effect.

[0043] Therefore, the driven blades 5 are positioned between the intersection of the central axes of the multiple outlet pipes 7 and the packing layer 2. This arrangement allows the driven blades 5 to more effectively guide the exhaust gas upwards along a predetermined path, orderly pass through the outlet pipes 7, and smoothly enter the packing layer 2 area. This arrangement of the driven blades 5 ensures that the flow direction and velocity of the exhaust gas within the device are further optimized, thereby improving the purification efficiency.

[0044] In actual operation, it is necessary to ensure that the rotational speed and tilt angle of the driven blade 5 match the velocity of the exhaust gas entering the tank, so as to maintain the orderly upward movement of the exhaust gas. This adaptive design ensures stable operation and efficient purification of the device under different operating conditions.

[0045] See Figure 2 , Figure 3 To enable the rotation of the driven shaft 6, this device has a drive shaft 9 at the lower end of the partition plate 3, which is connected to the driven shaft 6. The drive shaft 9 and the driven shaft 6 are connected through a transmission device, that is, the drive shaft 9 drives the driven shaft 6 to run. The design and position selection of the drive shaft 9 are crucial to the operating efficiency of the entire device. It ensures that the driven shaft 6 can rotate smoothly, thereby driving the driven blade 5 and providing an upward driving force for the exhaust gas.

[0046] Meanwhile, multiple drive blades 8 are fixedly installed on one side of the drive shaft 9. When exhaust gas enters the lower side of the tank 1 from the inlet pipe 4, it impacts the drive blades 8, causing the drive shaft 9 to rotate. The rotation of the drive shaft 9 drives the driven shaft 6 to rotate through the transmission structure, which in turn causes the driven blades 5 to rotate. This design allows the drive shaft 9 to start quickly after the exhaust gas enters the device, initiating the entire purification process.

[0047] To ensure that the drive shaft 9 can effectively drive the driven shaft 6 to rotate, a guide pipe 10 with an inverted L-shaped vertical projection is fixedly installed in the lower inner cavity of the tank 1. Its vertical section is connected to the air inlet pipe 4, and its horizontal section faces the drive blade 8. The guide pipe 10 guides the exhaust gas to the drive blade 8, ensuring effective impact and rotation of the drive shaft 9, thus ensuring the operation of the device. The design of the guide pipe 10 ensures that the exhaust gas can be effectively utilized, improving the operating efficiency of the device.

[0048] See Figure 4 To ensure that the side ends of the packing 202 are evenly coated with the purification liquid, and that the exhaust gas can fully contact the purification liquid as it passes through the gaps in the packing 202, this device includes a follower shaft 204 positioned between two positioning plates 201 in the packing layer 2. Multiple follower blades 205 are fixedly installed on the side ends of the follower shaft 204, which is level with the packing 202. The follower blades 205 rotate with the shaft, causing relative movement between the packing 202 and the exhaust gas, increasing the contact area and frequency, and improving purification efficiency. The design of the follower blades 205 ensures that the packing layer 2 can efficiently contact the exhaust gas, thereby improving purification efficiency.

[0049] See Figure 5 , Figure 6 To achieve the rotation of the follower shaft 204, this device ensures that the follower shaft 204 and the driven shaft 6 are connected through a transmission device, and the rotation of the follower shaft 204 is achieved through the driven shaft 6. The transmission device is designed to ensure that the follower shaft 204 and the driven shaft 6 rotate synchronously, ensuring stable operation of the device.

[0050] Furthermore, this device connects the follower shaft 204 and the driven shaft 6 through a reduction mechanism 12, so that the rotational speed of the follower shaft 204 is lower than that of the driven shaft 6, thereby reducing the burden on the driven shaft 6 and ensuring smooth linkage between the two under exhaust gas drive. The reduction mechanism 12 is well-designed to ensure stable and reliable operation of the device and effectively improve the energy efficiency ratio.

[0051] In practical applications, this utility model is as follows:

[0052] Preparation phase: Ensure all components of the device are installed correctly, and perform non-destructive testing on components such as the spray equipment 11, air inlet pipe 4, partition plate 3, air outlet pipe 7, driven shaft 6, drive shaft 9, guide pipe 10, and follower shaft 204. Add sufficient purification liquid to the spray equipment 11 to ensure adequate reserves.

[0053] Device startup: Turn on the exhaust gas source to allow the exhaust gas generated by the chlorination addition reaction to enter tank 1 through inlet pipe 4. The exhaust gas first reaches the lower space of tank 1.

[0054] Exhaust gas guidance and regulation: After entering through the inlet pipe 4, the exhaust gas is guided by the guide pipe 10 to impact the drive blades 8 on the drive shaft 9. The drive shaft 9 rotates, driving the driven shaft 6 to rotate through the transmission structure. The driven blades 5 on the driven shaft 6 rotate accordingly. Because there is an angle between the vertical centerline of the driven blades 5 and the central axis of the driven shaft 6, an upward driving force is provided for the exhaust gas. At the same time, multiple outlet pipes 7 introduce the exhaust gas from the lower space of the tank 1 into the upper space. The unique structural design of the outlet pipes 7 causes the exhaust gas to collide with each other and disperse in a diffused state under the packing layer 2.

[0055] Waste gas purification treatment: The spraying device 11 sprays purification liquid into the tank 1. The purification liquid is splashed onto the relatively upper positioning plate 201 by the spraying device 11, and moves downward through the through hole 203 under the influence of gravity to contact the packing 202. During this process, the waste gas moves upward through the through hole 203 on the relatively lower positioning plate 201 to contact the packing 202. The waste gas and the purification liquid simultaneously contact the packing 202, and gas-liquid mass transfer occurs, purifying the waste gas.

[0056] Improving purification efficiency: The follower shaft 204 and the driven shaft 6 are connected by a reduction gear 12. The rotation of the driven shaft 6 drives the follower shaft 204 to rotate. Through the rotation of the follower blades 205 on the side of the follower shaft 204, the packing 202 is placed in a relative motion state, thereby significantly increasing the contact area and contact frequency between the packing 202 and the exhaust gas. This design not only improves purification efficiency but also optimizes the pollutant removal rate in the exhaust gas treatment process.

[0057] Continuous monitoring and adjustment: During the operation of the device, observe the exhaust gas purification effect. Based on the rate at which the exhaust gas enters the tank 1, adjust the rotation speed and tilt angle of the driven blade 5 and the rotation speed of the follower shaft 204 appropriately to ensure that the exhaust gas and the purification liquid are in full contact to achieve the best purification effect.

[0058] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A tail gas purification and treatment device for the bromination reaction of pyrrolonitrile, comprising a tank (1), wherein a packing layer (2) is provided inside the tank (1), and a spraying device (11) is provided at the upper end of the tank (1), characterized in that: It also includes a partition plate (3) located on the lower side of the tank body (1), on which multiple air outlet pipes (7) are connected and connected, and the multiple air outlet pipes (7) are evenly distributed around the central axis of the partition plate (3); The angle between the central axis of each of the air outlet pipes (7) and the central axis of the partition plate (3) is less than 90 degrees, and the projection of each air outlet pipe (7) on the vertical plane is a trapezoidal structure, and the inner diameter of the lower end of each air outlet pipe (7) is greater than the inner diameter of its upper end. The intersection of the central axes of the plurality of the air outlet pipes (7) coincides with the central axis of the partition plate (3), and the intersection is located below the packing layer (2); The tank (1) is connected to an air inlet pipe (4) on its lower side. The waste gas generated by the chlorination addition reaction enters the tank (1) through the air inlet pipe (4), and the height of the air inlet pipe (4) is lower than the height of the partition plate (3).

2. The tail gas purification and treatment device for the bromination reaction of pyrrolonitrile according to claim 1, characterized in that: The upper end of the partition plate (3) is rotatably connected to a driven shaft (6) arranged along the vertical axis, and multiple driven blades (5) are fixedly connected to the driven shaft (6); The lower end of the partition plate (3) is connected to a drive shaft (9) arranged along the vertical axis. The drive shaft (9) is connected to the driven shaft (6), and multiple drive blades (8) are fixedly connected to the side end of the drive shaft (9).

3. The tail gas purification and treatment device for the bromination reaction of pyrrolonitrile according to claim 2, characterized in that: There is an angle between the vertical centerline of the driven blade (5) and the central axis of the driven shaft (6). The driven blade (5) is used to drive the airflow upward, and the driven blade (5) is located between the intersection of the central axes of multiple air outlet pipes (7) and the packing layer (2).

4. The tail gas purification and treatment device for the bromination reaction of pyrrolonitrile according to claim 2, characterized in that: The filler layer (2) includes two positioning plates (201) arranged vertically, with filler (202) filling between the two positioning plates (201), and each positioning plate (201) has multiple through holes (203).

5. The tail gas purification and treatment device for the bromination reaction of pyrrolonitrile according to claim 4, characterized in that: A follower shaft (204) is also provided between the two positioning plates (201). Multiple follower blades (205) are fixedly connected to the side end of the follower shaft (204). The follower blades (205) and the packing (202) are on the same horizontal plane. The follower shaft (204) and the driven shaft (6) are connected by a reduction mechanism (12). The rotational speed of the follower shaft (204) is less than that of the driven shaft (6).

6. The tail gas purification and treatment device for the bromination reaction of pyrrolonitrile according to claim 2, characterized in that: A guide pipe (10) with an inverted L-shaped structure in the vertical plane projection is fixedly connected to the lower inner cavity of the tank (1). The vertical section of the guide pipe (10) is connected to the air intake pipe (4), and the horizontal section of the guide pipe (10) faces the drive blade (8).

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