Efficient ABS resin pellet drying device based on hot air

Abstract

The utility model discloses a hot air-based ABS (acrylonitrile butadiene styrene) resin pellet efficient drying device which comprises a treatment bin, a drying device is arranged in the treatment bin, a control device is arranged on one side of the treatment bin and comprises a fixed pipe, a control sleeve, a connecting pipe, a control panel, a control shaft, a control groove and a rotating shaft, and one end of the control panel is rotatably connected with the control sleeve through the rotating shaft; a control shaft arranged on the other side of the control panel is slidably located in a control groove, the control groove is formed in the connecting pipe, a reinforcing mechanism is arranged on the outer side of the fixing pipe and comprises a clamping rail, a clamping spring, a clamping block, a clamping groove, a clamping sleeve and a fixing block, the clamping rail is installed on one side of the control sleeve, the clamping spring is connected with the clamping block, and the clamping groove is connected with the clamping sleeve. The clamping block is arranged on the outer side of the clamping rail in a sliding mode through the clamping groove, the clamping sleeve is connected with the fixing pipe through threads, and the fixing block is installed on the outer side of the fixing pipe, and the three technical problems that natural drying efficiency is low, the hot air speed adjusting capacity is insufficient, and the stability of an air speed adjusting structure is poor are solved.

Description

A high-efficiency drying device for ABS resin granules based on hot air Technical Field

[0001] This utility model relates to the field of high-efficiency drying technology for ABS resin granules, and more specifically, it relates to a high-efficiency drying device for ABS resin granules based on hot air. Background Technology

[0002] Against the backdrop of increasingly fierce competition in global manufacturing, ABS resin, as one of the basic materials of modern industry, is widely used in many fields such as electronics, automobiles, home appliances and daily necessities due to its excellent physical and chemical properties. However, the drying process of ABS resin granules has always been a technical challenge in terms of efficiency and quality.

[0003] In existing industrial production technology, the drying process of ABS resin granules mainly relies on a simple natural wind drying mode. This involves spreading the raw material in a specific container and allowing moisture to evaporate through natural airflow. While this traditional method is simple to operate and has low energy consumption, it has fundamental limitations: First, natural wind drying is heavily dependent on environmental conditions, significantly affected by external factors such as weather, season, and geographical location. This makes precise control of the drying process difficult, resulting in a slow and unstable drying rate, especially in high humidity environments where drying efficiency drops drastically. Second, relying on natural air convection results in low heat and mass transfer efficiency, failing to create effective forced convection and leading to slow moisture evaporation. Furthermore, the uneven distribution of temperature and humidity within the drying area easily causes uneven drying, resulting in some areas being over-dried while others are excessively humid, failing to meet the continuous, efficient, and uniform production requirements of modern manufacturing. This inefficient method of passive drying relying on natural wind not only significantly extends the production cycle and increases inventory and site costs but also leads to unstable drying quality, severely restricting the production efficiency and product quality of ABS resin products.

[0004] To address the low efficiency of natural drying, a number of improved drying devices using hot air technology have indeed emerged in the industry. However, these devices have revealed a serious deficiency in hot air speed adjustment capabilities during practical applications: most improved equipment adopts a fixed wind speed design, lacking the ability to make fine adjustments according to actual needs; different batches and specifications of ABS resin granules vary in particle size, morphology, initial moisture content, and production process requirements, necessitating optimal wind speed parameters that cannot meet these diverse needs; and ideal wind speed parameters exist at different stages of the drying process (such as initial high-speed dehumidification and later stable dehydration). Significant differences exist; a fixed wind speed cannot achieve the optimal drying curve. Changes in raw material loading also require corresponding wind speed adjustments to ensure uniform heat and airflow contact per unit mass of granules. Seasonal changes in ambient temperature and humidity also necessitate dynamic adjustments to the optimal wind speed. With rising energy costs, a fixed wind speed design often leads to energy waste and fails to achieve the energy-saving goal of "on-demand air supply." This technical defect, where the hot air input speed cannot be flexibly adjusted, makes it difficult to simultaneously optimize the efficiency and quality of the drying process. This not only fails to fully leverage the potential advantages of hot air drying but may also lead to a series of secondary problems such as uneven drying, energy waste, and raw material loss.

[0005] To address the aforementioned wind speed regulation issues, some advanced manufacturers have introduced new drying equipment with integrated wind speed control functions, initially achieving adjustability of hot air input speed. However, these devices still suffer from serious structural instability: most speed control devices are prone to loosening during long-term operation; the continuous impact of high-temperature, high-speed hot air inside the drying device generates significant vibration and lateral pressure on the speed control mechanism; especially in large industrial drying equipment, the powerful centrifugal force and airflow pulsation generated by the fan apply periodic loads to the piping system and regulating components, and the instantaneous pressure fluctuations during equipment start-up and shutdown pose a severe challenge to the precision regulating mechanism, further exacerbating the loosening trend of connection points and gradually destroying the original precise adjustment position. This simple and unstable technical design leads to the wind speed regulation structure often unexpectedly shifting due to internal wind impact and equipment vibration during actual production, making it impossible to maintain stable, resulting in fluctuations in drying efficiency, increased energy consumption, and unstable quality; in severe cases, it can cause system air pressure disturbances, airflow short circuits, or even equipment damage. This not only fails to ensure the stability and uniformity of the ABS resin granule drying process but also increases equipment maintenance costs and the risk of production interruption. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] In view of the problems existing in the prior art, this utility model provides a high-efficiency drying device for ABS resin granules based on hot air, so as to solve the technical problems mentioned in the background art.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, this utility model provides the following technical solution: a high-efficiency drying device for ABS resin granules based on hot air, comprising a processing chamber, in which a drying device is installed, and a control device is provided on one side of the processing chamber. The control device includes a fixed pipe, a control sleeve, a connecting pipe, a control plate, a control shaft, a control groove, and a rotating shaft. The two ends of the control sleeve are rotatably connected to the fixed pipe and the connecting pipe, respectively. One end of the control plate is rotatably connected to the control sleeve via the rotating shaft. The control shaft on the other side of the control plate slides in the control groove, which is located on the connecting pipe. A reinforcement mechanism is provided on the outside of the fixed pipe, comprising a locking rail, a locking spring, a locking block, a locking groove, a locking sleeve, and a fixing block. Multiple locking rails are fixedly installed on one side of the control sleeve. The two ends of the locking spring are connected to two adjacent locking blocks, respectively. The locking block is slidably disposed on the outside of the locking rail via the locking groove, which is located on one side of the locking block. The locking sleeve is movably connected to the fixed pipe via threads. Multiple fixing blocks are fixedly installed on the outside of the fixed pipe.

[0010] The present invention is further configured such that the drying device includes an inner cylinder, a fixed base, an air inlet chamber, a discharge port, and a cavity. The inner cylinder is detachably installed inside the processing chamber. The cavity is opened between the inner cylinder and the processing chamber. The discharge port is opened on the side wall of the processing chamber. The air inlet chamber communicates with the cavity. The air inlet chamber is fixedly installed on one side of the processing chamber. The processing chamber is detachably installed above the fixed base.

[0011] The present invention is further configured such that the inner cylinder sidewall has multiple through holes.

[0012] The present invention is further configured such that a spiral frame is rotatably provided in the inner cylinder, and a drive assembly is installed in the fixed seat, the output end of the drive assembly being connected to the bottom end of the spiral frame.

[0013] The present invention is further configured such that both the positioning rail and the positioning groove are T-shaped structures.

[0014] The present invention is further configured such that the fixing block is designed as a columnar structure.

[0015] The present invention is further configured such that a locking wheel is rotatably provided on one side of the locking block, and the locking wheel is locked between two fixing blocks.

[0016] The present invention is further configured such that the control board has a plurality of control holes.

[0017] (III) Beneficial Effects

[0018] Compared with the prior art, this utility model provides a high-efficiency drying device for ABS resin granules based on hot air, which has the following beneficial effects:

[0019] 1. The drying device, through the ingenious coordination of the inner cylinder, fixed base, air inlet, discharge port, cavity, through holes, spiral frame, and drive assembly, completely solves the core problem of low efficiency in existing technologies that rely on natural wind power for drying. Its main advantages are: multiple through holes on the side wall of the inner cylinder enable all-round, large-area contact between hot air and resin granules, significantly improving heat transfer efficiency; the number and distribution of through holes are carefully designed to ensure uniform airflow distribution within the inner cylinder, avoiding the localized over-drying or excessively high humidity phenomena common in traditional drying methods; the cavity structure between the inner cylinder and the processing chamber... A hot air buffer zone is formed, making the temperature and pressure of the hot air entering the inner cylinder more uniform and stable. The drive assembly, in conjunction with the rotating design of the screw frame, enables continuous and uniform material conveying, avoiding accumulation. At the same time, the rotation of the screw frame can continuously agitate the resin granules, ensuring that each granule is fully in contact with the hot air. The ingenious connection structure between the air inlet chamber and the cavity ensures that the hot air first enters the cavity and then is evenly distributed into the inner cylinder, avoiding local overheating that may be caused by direct air intake. This innovative drying device structural design significantly improves the drying efficiency of ABS resin granules and shortens the production cycle.

[0020] 2. The control device, through an ingenious combination of fixed pipes, control sleeves, connecting pipes, control boards, control shafts, control slots, and rotating shafts, achieves precise and controllable adjustment of the hot air input speed. Its core advantages lie in: the rotatable connection design of the control sleeve with the fixed and connecting pipes, allowing operators to achieve complex wind speed adjustments through simple rotation; the movement of multiple control holes on the control board and the movement of the control board itself cleverly changes the cross-sectional area of ​​the airflow channel, thereby precisely controlling the wind speed. The entire control device design fully considers ease of operation, allowing operators to adjust the wind speed without interrupting production. This innovative control device design enables the hot air drying system to flexibly adjust the optimal wind speed parameters according to the characteristics of different batches and specifications of ABS resin granules and the requirements of the production process, achieving wind speed optimization at different stages of the drying process, meeting the uniform drying requirements under different loading capacities, and dynamically adjusting according to seasonal changes in ambient temperature and humidity, effectively achieving the energy-saving goal of "on-demand air supply," and significantly improving the simultaneous optimization capability of drying efficiency and quality.

[0021] 3. The reinforcement mechanism, through an innovative combination of locking rails, locking springs, locking blocks, locking grooves, locking sleeves, fixing blocks, and locking wheels, fundamentally ensures structural stability after wind speed adjustment. Its unique advantages are: the locking rails and locking grooves adopt a T-shaped structure design, enhancing the stability and guidance of the locking blocks during sliding; the locking springs provide appropriate preload while resetting the locking blocks, ensuring structural stability in the locked state; the locking wheel design improves locking strength, and the fixing block provides reliable positioning support for the locking wheel, forming a multi-point locking mechanism; the threaded connection between the locking sleeve and the fixing tube achieves double locking protection, maintaining stability even under extreme vibration conditions; the locking sleeve limits the outer side of the locking wheel. This constitutes a second safety barrier to prevent accidental loosening. The distribution design of multiple locking rails and blocks ensures that the locking force is evenly distributed, avoiding local stress concentration. This multi-locking reinforcement mechanism design can maintain the stability of the control device even under harsh conditions such as continuous impact of high-temperature and high-speed hot air, strong centrifugal force and airflow pulsation generated by the fan, and instantaneous pressure fluctuations during equipment start-up and shutdown. It effectively prevents the wind speed adjustment structure from loosening and shifting due to internal wind impact and equipment vibration, ensuring that the adjusted input wind speed remains stable. This guarantees the continuity of the ABS resin granule drying process and the consistency of product quality, while significantly reducing equipment maintenance costs and the risk of production interruption, providing a solid guarantee for efficient and stable industrial production. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the overall structure of a high-efficiency drying device for ABS resin granules based on hot air according to this utility model.

[0023] Figure 2 is a cross-sectional structural diagram of this utility model;

[0024] Figure 3 is a structural schematic diagram of the control device and reinforcement mechanism in this utility model;

[0025] Figure 4 is a schematic diagram of the dispersed structure of the control device and the reinforcement mechanism in this utility model;

[0026] Figure 5 is a cross-sectional structural diagram of the control device and reinforcement mechanism in this utility model.

[0027] In the diagram: 1. Processing chamber; 2. Fixed pipe; 3. Control sleeve; 4. Connecting pipe; 5. Control board; 6. Control shaft; 7. Control groove; 8. Rotating shaft; 9. Locking rail; 10. Locking spring; 11. Locking block; 12. Locking groove; 13. Locking sleeve; 14. Fixed block; 15. Inner cylinder; 16. Fixed seat; 17. Air inlet chamber; 18. Discharge port; 19. Cavity; 20. Through hole; 21. Screw frame; 22. Drive assembly; 23. Locking wheel; 24. Control hole. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0030] In this utility model, unless otherwise stated, the orientations used, such as "up" and "down", usually refer to the direction shown in the accompanying drawings, or to the vertical, perpendicular, or gravitational direction; similarly, for ease of understanding and description, "left" and "right" usually refer to the left and right shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0031] Please refer to Figures 1-5. A high-efficiency drying device for ABS resin granules based on hot air includes a processing chamber 1, in which a drying device is installed. A control device is installed on one side of the processing chamber 1. The control device includes a fixed pipe 2, a control sleeve 3, a connecting pipe 4, a control plate 5, a control shaft 6, a control groove 7, and a rotating shaft 8. The two ends of the control sleeve 3 are rotatably connected to the fixed pipe 2 and the connecting pipe 4, respectively. One end of the control plate 5 is rotatably connected to the control sleeve 3 via the rotating shaft 8. The control shaft 6, located on the other side of the control plate 5, slides in the control groove 7. The control groove 7 is formed by... A reinforcing mechanism is provided on the outside of the connecting pipe 4 and the fixed pipe 2. The reinforcing mechanism includes a locking rail 9, a locking spring 10, a locking block 11, a locking groove 12, a locking sleeve 13, and a fixing block 14. Multiple locking rails 9 are fixedly installed on one side of the control sleeve 3. The two ends of the locking spring 10 are respectively connected to two adjacent locking blocks 11. The locking block 11 is slidably set on the outside of the locking rail 9 through the locking groove 12. The locking groove 12 is opened on one side of the locking block 11. The locking sleeve 13 is movably connected to the fixed pipe 2 through threads. Multiple fixing blocks 14 are fixedly installed on the outside of the fixed pipe 2.

[0032] The drying device includes an inner cylinder 15, a fixed base 16, an air inlet 17, a discharge port 18, and a cavity 19. The inner cylinder 15 is detachably installed inside the processing chamber 1. The cavity 19 is opened between the inner cylinder 15 and the processing chamber 1. The discharge port 18 is opened on the side wall of the processing chamber 1. The air inlet 17 is connected to the cavity 19. The air inlet 17 is fixedly installed on one side of the processing chamber 1. The processing chamber 1 is detachably installed above the fixed base 16.

[0033] Multiple through holes 20 are provided on the side wall of the inner cylinder 15.

[0034] A screw frame 21 is rotatably mounted in the inner cylinder 15, and a drive assembly 22 is installed in the fixed seat 16. The output end of the drive assembly 22 is connected to the bottom end of the screw frame 21.

[0035] In this embodiment, when the device is needed, the input wind speed is first adjusted, then the hot air device connected to one end of the connecting pipe 4 is turned on to input hot air into the air inlet chamber 17. Then, resin particles are slowly added into the inner cylinder 15, and the drive assembly 22 is turned on so that the drive assembly 22 drives the spiral frame 21 to rotate slowly, thereby slowly feeding the resin particles. Then, the hot air entering the air inlet chamber 17 will enter the cavity 19, and then enter the inner side of the inner cylinder 15 through multiple through holes 20 opened on the side wall of the inner cylinder 15 to achieve uniform drying of the resin particles conveyed inside. Then, the dried resin particles will finally be discharged through the discharge port 18, and then the dried resin particles will be collected by the external collection device.

[0036] Please refer to Figures 3-5 for a further implementation of the overall device: both the positioning rail 9 and the positioning slot 12 are T-shaped structures.

[0037] The fixing block 14 is designed as a column structure.

[0038] A locking wheel 23 is provided on one side of the locking block 11, which is rotated and locked between two fixing blocks 14.

[0039] The control panel 5 has multiple control holes 24.

[0040] More specifically, when the hot air input speed needs to be adjusted as required, firstly, rotate the locking sleeve 13 in the forward direction, causing it to move along the threaded outer wall of the fixed pipe 2, so that the locking sleeve 13 no longer limits the outer side of the locking wheel 23. Then, rotate the control sleeve 3 in the forward direction, causing it to drive one side of the locking rail 9 to rotate. Then, the locking rail 9 drives the locking block 11 to rotate in the forward direction through the locking groove 12, causing the locking wheel 23 to move out from between the two fixed blocks 14. Then, the locking wheel 23 drives the locking block 11 to slide outward along the locking rail 9 and the locking groove 12, and causes the locking block 11 to drive the locking spring 10 to stretch outward. At the same time, the control sleeve 3 drives the control plate 5 to move through the rotating shaft 8, causing the control plate 5 to drive the control shaft 6 to slide along the control groove 7 on the other side, causing the control plate 5 to drive multiple control holes 24 to move. The movement of the control holes 24 in coordination with the movement of the control plate 5 changes the position of the control plate 5. The internal flow area of ​​the connecting pipe 4 is changed to adjust the input flow rate. When the appropriate flow rate is adjusted, the control sleeve 3 is stopped from rotating, and the locking rail 9 and locking groove 12 cooperate to move the locking block 11 between the two corresponding fixed blocks 14. Then, the locking spring 10 resets and pulls the locking block 11 to slide inward along the locking rail 9 and locking groove 12, so that the locking block 11 drives the locking wheel 23 to lock between the two corresponding fixed blocks 14. Then, the locking sleeve 13 is rotated in the opposite direction, so that the locking sleeve 13 moves and resets along the thread on the outer wall of the fixed pipe 2. Then, the inner wall of the locking sleeve 13 re-limits the outer side of the locking wheel 23, so that the locking wheel 23 and the locking block 11 cannot move, thereby limiting the control sleeve 3 and preventing the control sleeve 3 from rotating accidentally. This ensures the structural stability after the flow rate adjustment, ensures the stable input of hot air, and thus ensures stable drying operation.

[0041] In summary, when using or operating the equipment: First, adjust the input air speed, then turn on the hot air device connected to one end of the connecting pipe 4 to input hot air into the air inlet chamber 17. Then, slowly add resin particles into the inner cylinder 15 and turn on the drive assembly 22 to drive the screw frame 21 to rotate slowly, thus slowly feeding the resin particles. The hot air entering the air inlet chamber 17 will then enter the cavity 19 and enter the inner cylinder 15 through multiple through holes 20 on the side wall of the inner cylinder 15 to achieve uniform drying of the resin particles conveyed inside. The dried resin particles will then be discharged through the discharge port 18 and collected by the external collection device.

[0042] When the hot air input speed needs to be adjusted as required, first rotate the locking sleeve 13 clockwise, causing it to move along the threaded outer wall of the fixed pipe 2, so that the locking sleeve 13 no longer limits the outer side of the locking wheel 23. Then, rotate the control sleeve 3 clockwise, causing it to drive one side of the locking rail 9 to rotate. The locking rail 9 then drives the locking block 11 to rotate clockwise through the locking groove 12, causing the locking wheel 23 to move out from between the two fixed blocks 14. The locking wheel 23 then drives the locking block 11 to slide outward along the locking rail 9 and the locking groove 12, causing the locking block 11 to drive the locking spring 10 to stretch outward. At the same time, the control sleeve 3 drives the control plate 5 to move through the rotating shaft 8, causing the control plate 5 to drive the control shaft 6 to slide along the control groove 7 on the other side, causing the control plate 5 to drive multiple control holes 24 to move. The movement of the control holes 24, in conjunction with the movement of the control plate 5, changes the connection. The internal flow area of ​​pipe 4 is adjusted to achieve the purpose of adjusting the input flow rate. When the appropriate flow rate is adjusted, the rotation of control sleeve 3 is stopped, and the locking rail 9 and locking groove 12 cooperate to move the locking block 11 between the two corresponding fixed blocks 14. Then, the locking spring 10 resets and pulls the locking block 11 to slide inward along the locking rail 9 and locking groove 12, so that the locking block 11 drives the locking wheel 23 to lock between the two corresponding fixed blocks 14. Then, the locking sleeve 13 is rotated in the opposite direction, so that the locking sleeve 13 moves and resets along the thread on the outer wall of the fixed pipe 2. Then, the inner wall of the locking sleeve 13 re-limits the outer side of the locking wheel 23, so that the locking wheel 23 and the locking block 11 cannot move, thereby limiting the control sleeve 3 and preventing the control sleeve 3 from rotating accidentally. This ensures the structural stability after the flow rate adjustment, ensures the stable input of hot air, and thus ensures stable drying operation.

[0043] Of all the solutions mentioned above, those involving the connection between two components can be selected according to the actual situation, such as welding, bolt and nut connection, bolt or screw connection, or other known connection methods, which will not be elaborated here. For all the fixed connections mentioned above, welding is preferred. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this utility model. The scope of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency drying device for ABS resin granules based on hot air, comprising a processing chamber (1), characterized in that: A drying device is installed in the processing chamber (1). A control device is installed on one side of the processing chamber (1). The control device includes a fixed pipe (2), a control sleeve (3), a connecting pipe (4), a control plate (5), a control shaft (6), a control groove (7), and a rotating shaft (8). The two ends of the control sleeve (3) are rotatably connected to the fixed pipe (2) and the connecting pipe (4) respectively. One end of the control plate (5) is rotatably connected to the control sleeve (3) through the rotating shaft (8). The control shaft (6) on the other side of the control plate (5) slides in the control groove (7). The control groove (7) is opened in the connecting pipe (4) at some points. A reinforcement mechanism is provided on the outside of the fixed tube (2). The reinforcement mechanism includes a locking rail (9), a locking spring (10), a locking block (11), a locking groove (12), a locking sleeve (13), and a fixing block (14). Multiple locking rails (9) are fixedly installed on one side of the control sleeve (3). The locking spring (10) is connected to two adjacent locking blocks (11). The locking block (11) is slidably disposed on the outside of the locking rail (9) through the locking groove (12). The locking sleeve (13) is movably connected to the fixed tube (2) by a thread. Multiple fixing blocks (14) are installed on the outside of the fixed tube (2).

2. The high-efficiency drying device for ABS resin granules based on hot air according to claim 1, characterized in that: The drying device includes an inner cylinder (15), a fixed base (16), an air inlet (17), a discharge port (18), and a cavity (19). The inner cylinder (15) is detachably installed inside the processing chamber (1). The cavity (19) is opened between the inner cylinder (15) and the processing chamber (1). The discharge port (18) is opened on the side wall of the processing chamber (1). The air inlet (17) is connected to the cavity (19). The air inlet (17) is fixedly installed on one side of the processing chamber (1). The processing chamber (1) is detachably installed above the fixed base (16).

3. The high-efficiency drying device for ABS resin granules based on hot air according to claim 2, characterized in that: The inner cylinder (15) has multiple through holes (20) on its side wall.

4. The high-efficiency drying device for ABS resin granules based on hot air according to claim 3, characterized in that: The inner cylinder (15) is provided with a rotating screw frame (21), and the fixed seat (16) is provided with a drive assembly (22), the output end of the drive assembly (22) is connected to the bottom end of the screw frame (21).

5. A high-efficiency drying device for ABS resin granules based on hot air according to any one of claims 1-4, characterized in that: Both the positioning rail (9) and the positioning groove (12) are T-shaped structures.

6. The high-efficiency drying device for ABS resin granules based on hot air according to claim 5, characterized in that: The fixing block (14) is designed as a column structure.

7. The high-efficiency drying device for ABS resin granules based on hot air according to claim 6, characterized in that: The locking block (11) has a locking wheel (23) on one side that rotates, and the locking wheel (23) is engaged between two fixing blocks (14).

8. The high-efficiency drying device for ABS resin granules based on hot air according to claim 1, characterized in that: The control panel (5) has multiple control holes (24).

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