A hand dryer

Abstract

This utility model discloses a hand dryer, including a shell with an air chamber inside. The air chamber has an air inlet at its upper end and an air outlet at its lower end. The diameter of the air chamber gradually decreases from the middle to both ends. A fan is installed at the air inlet. A heating chamber is located in the middle of the air chamber, and an electric heating device is installed inside the heating chamber. The air chamber, from top to bottom, consists of an air inlet, a heating chamber, and an air outlet, with the diameter gradually increasing and then decreasing again. The smaller air inlet facilitates the rapid entry of outside air, the larger diameter heating chamber provides a larger heating area for rapid heating, and the smaller air outlet facilitates the rapid expulsion of the heated air.

Description

Technical Field

[0001] This utility model relates to the field of hand dryer equipment technology, and specifically to a hand dryer. Background Technology

[0002] In modern life, hand dryers are a common sanitary appliance widely used in various settings such as hotels, restaurants, research institutions, hospitals, public entertainment venues, and home bathrooms. After washing hands, using a hand dryer can quickly dry hands, effectively avoiding the cross-infection of bacteria that may occur when drying with a towel. It also aligns with environmental protection principles by reducing the use of paper towels.

[0003] Existing hand dryers generally include a fan, which works by drawing in outside air, heating it, and then expelling the hot air to dry hands. In this process, improving the speed of air intake and exhaust is a key consideration in hand dryer design. Air velocity directly affects drying efficiency; slow intake and exhaust speeds lead to longer drying times and a poorer user experience. For example, in public places where hand dryers are used frequently, slow drying times can cause queues.

[0004] Furthermore, the proper installation of the heating element in the airflow path is also a crucial aspect of hand dryer design. The installation location and method of the heating element not only affect heating efficiency but can also interfere with the airflow field. Improper installation can lead to uneven air heating, with some areas experiencing excessively high temperatures that could burn the user's hands, while other areas may have insufficiently cool temperatures to effectively dry hands. Simultaneously, improper installation can increase airflow resistance, further reducing the speed of air intake and exhaust, thus impacting the overall performance of the hand dryer. Utility Model Content

[0005] In view of the problems pointed out in the background art, this utility model proposes a hand dryer to solve the above-mentioned technical problems.

[0006] The technical solution of this utility model is implemented as follows:

[0007] A hand dryer includes a housing with an air chamber inside. The air chamber has an air inlet at the upper end and an air outlet at the lower end. The diameter of the air chamber gradually decreases from the middle to the top and bottom. A fan is installed at the air inlet. A heating chamber is located in the middle of the air chamber, and an electric heating device is installed in the heating chamber.

[0008] The present invention is further configured such that the electric heating device is adapted to and connected to the heating chamber, and the electric heating device has a number of ventilation holes that penetrate through its upper and lower sides.

[0009] The present invention is further configured such that the air chamber is formed by connecting the first part and the second part vertically, with the air inlet located on the first part and the heating chamber and the air outlet located on the second part; the side of the electric heating device is provided with wiring terminals, and the side wall of the heating chamber is provided with a mounting groove that runs through its inner and outer sides and the top side; the first part is provided with a plug strip that is adapted to the mounting groove to close the mounting groove.

[0010] The present invention is further configured such that a support portion is provided on the inner wall of the heating chamber, and a downwardly extending restriction portion is provided on the first part. The restriction portion and the support portion restrict the vertical movement of the electric heating device on the upper and lower sides of the electric heating device.

[0011] The present invention is further configured such that the air inlet is connected to a ring-shaped circuit board, the circuit board being coaxial with the air inlet and spaced apart vertically.

[0012] The present invention is further provided that the lower side of the outer shell is provided with an opening corresponding to the air outlet.

[0013] The present invention is further configured such that an air inlet is provided on the lower side of the outer shell, and a filter screen is provided on the inner side of the air inlet.

[0014] The present invention is further provided that a sensing device is provided on the lower side of the outer casing.

[0015] The present invention is further configured such that the outer shell includes a base plate and a cover, and the air chamber is fixedly connected to the base plate.

[0016] The present invention is further configured such that the first part and the second part are fixedly connected by screws.

[0017] By adopting the above technical solution, the beneficial effects of this utility model are as follows:

[0018] The hand dryer provided by this utility model has an air inlet, a heating chamber, and an air outlet arranged from top to bottom. The diameter of the air inlet gradually increases and then decreases. The smaller air inlet helps the outside air to enter quickly, the larger diameter heating chamber has a larger heating area, which helps to heat the air quickly, and the smaller air outlet helps to blow out the heated air quickly.

[0019] The electric heating device is adapted to be installed in the heating chamber, allowing air to pass through only the ventilation holes on the electric heating device. The electric heating device has a large area and high heating efficiency.

[0020] The vertical electric heating device is restricted and fixed by the limiting part and the supporting part. The side wall of the heating chamber is provided with a mounting groove for the wiring terminals of the power supply heating device to extend out. This facilitates the installation of the electric heating device. The electric heating device can be fixed without the help of screws or other fasteners. Its structural design is reasonable and ingenious. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] Figure 2 This is an exploded view of the present invention.

[0024] Figure 3 This is a schematic diagram of the lower part of the present invention.

[0025] Figure 4 This is an exploded view of the present invention. Figure 2 .

[0026] Figure 5 This is a schematic diagram of the structure of the air chamber of this utility model.

[0027] Figure 6 This is a cross-sectional view of the air chamber of this utility model.

[0028] Figure 7 This is an exploded view of the air chamber of this utility model. Figure 1 .

[0029] Figure 8 This is an exploded view of the air chamber of this utility model. Figure 2 .

[0030] Figure 9 This is a schematic diagram of the second part of the present invention and the electric heating device.

[0031] Figure 10 This is a structural schematic diagram of the second part of this utility model.

[0032] Figure 11 This is a schematic diagram of the structure of the first part of this utility model.

[0033] The following are the labels in the attached drawings: 1. Outer shell; 2. Air chamber; 21. First part; 22. Second part; 23. Mounting groove; 24. Connecting strip; 25. Support part; 26. Restricting part; 3. Air inlet; 4. Air outlet; 5. Fan; 6. Heating chamber; 7. Electric heating device; 71. Wiring terminal; 9. Air inlet hole; 8. Circuit board; 10. Filter screen; 11. Sensing device; 12. Base plate; 13. Cover. Detailed Implementation

[0034] 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.

[0035] For reference as follows Figures 1-11 The present invention will be described as follows:

[0036] Example: A hand dryer includes a housing 1, an air chamber 2 inside the housing 1, an air inlet 3 at the upper end of the air chamber 2, and an air outlet 4 at the lower end of the air chamber 2.

[0037] The diameter of the air chamber 2 is set to gradually decrease from the middle to the top and bottom ends.

[0038] The air inlet 3 is equipped with a fan 5, and the middle of the air chamber 2 is a heating chamber 6, which is equipped with an electric heating device 7.

[0039] The lower side of the outer casing 1 is provided with an opening that corresponds to and is connected to the air outlet 4, and the air outlet 4 extends to the opening.

[0040] The lower side of the outer casing 1 is provided with multiple air inlets 9, and the inner side of the air inlets 9 is provided with a filter screen 10.

[0041] Under the action of the fan 5, outside air enters the interior of the outer casing 1 through the air inlet 9 and the filter screen 10, and then enters the air chamber 2 through the air inlet 3. After being heated by the electric heating device 7, hot air is blown out from the air outlet 4.

[0042] The air chamber 2 of this hand dryer features a unique diameter variation design, with its diameter gradually decreasing from the middle to the top and bottom ends, creating a shape that is narrow at both ends and wide in the middle. This structure aligns with aerodynamic principles. During airflow, when fluid passes through channels with different cross-sectional areas, according to the continuity equation, the fluid velocity is inversely proportional to the channel cross-sectional area. The narrower design at both ends of the air chamber, powered by the fan 5, accelerates the airflow when entering and exiting the air chamber, thus improving the efficiency of air intake and exhaust.

[0043] Air inlet 3 is located at the upper end of air chamber 2, where fan 5 is installed. With its smaller diameter, air inlet 3 allows outside air to enter air chamber 2 more quickly due to the pressure difference generated by fan 5 when it operates. Compared to a larger diameter air inlet, the smaller diameter inlet concentrates the amount of air passing through per unit time, resulting in faster air intake and improved air intake efficiency for the hand dryer, providing sufficient airflow for subsequent heating and ventilation processes.

[0044] The heating chamber 6 in the middle of the air chamber 2 has a large diameter, which significantly increases the contact area between the air and the electric heating device 7. According to the principle of heat transfer, under the same heating power and time conditions, the larger the contact area, the more complete the heat exchange. The larger heating chamber 6 allows the air to stay in it for a longer time, fully absorbing the heat generated by the electric heating device 7, achieving rapid and uniform heating. Compared to a small heating chamber, the large-diameter heating chamber 6 can significantly improve heating efficiency, ensuring that the temperature of the blown hot air is suitable and stable, effectively shortening the hand-drying time.

[0045] Air outlet 4 is located at the lower end of air chamber 2 and also adopts a smaller diameter design. After being heated by heating chamber 6, the air passes through the smaller diameter air outlet 4. Due to the smaller cross-sectional area of ​​the channel, the air velocity is further increased, allowing the hot air to be blown out at a higher speed. The high-speed hot air can more quickly remove moisture from the hands, accelerating the evaporation rate and thus improving drying efficiency. At the same time, the smaller air outlet 4 also has a certain converging effect on the hot air, making the hot air more concentrated on the hands and enhancing the drying effect.

[0046] Multiple air inlets 9 are provided on the lower side of the outer casing 1 to provide ample outside air for the hand dryer. A filter 10 inside the air inlets 9 effectively filters dust, hair, and other impurities from the outside air. This not only prevents impurities from entering the hand dryer, avoiding wear or blockage of components such as the fan 5 and electric heating device 7, thus affecting the normal operation and lifespan of the equipment, but also ensures that the blown hot air is clean and hygienic, preventing impurities from affecting the user experience or posing a potential threat to user health.

[0047] The electric heating device 7 is fitted and connected to the heating chamber 6, a design that ensures a tight fit between the two without any gaps. This fitting connection precisely defines the airflow path, ensuring that air entering the heating chamber 6 can only pass through the ventilation holes on the electric heating device 7. This precise structural design effectively prevents air from "taking shortcuts" and bypassing the electric heating device 7, guaranteeing that every unit of air entering the heating chamber 6 makes full contact with the electric heating device 7, laying the foundation for efficient heating.

[0048] The electric heating device 7 has several ventilation holes extending through its top and bottom sides. These ventilation holes play a crucial role in airflow and heat exchange. The presence of these holes provides a clear flow path for air, allowing it to pass through the electric heating device 7 in an orderly manner. Simultaneously, the ventilation holes increase the contact boundary between the air and the electric heating device 7, resulting in a larger surface area of ​​air contacting the device 7 as it flows through them, thereby improving heat exchange efficiency.

[0049] The electric heating device 7 is fitted and installed within the heating chamber 6, strictly limiting the airflow path. This design significantly improves heating efficiency. Since air can only contact the electric heating device 7 through the ventilation holes, ineffective heat transfer is avoided, allowing the heat generated by the electric heating device 7 to be absorbed by the air to the maximum extent. Simultaneously, the fitted installation method ensures the stability of the electric heating device 7 within the heating chamber 6, reducing airflow turbulence caused by device shaking or displacement, further enhancing heating stability and efficiency.

[0050] The air chamber 2 is formed by connecting the first part 21 and the second part 22 vertically, which are then fixed together with screws. This split design has several advantages. From a manufacturing perspective, the split structure facilitates individual processing of each part, reducing processing difficulty and cost, while also facilitating quality inspection and control of different components. During installation and maintenance, the split structure makes disassembly and assembly more convenient. If a part malfunctions or needs replacement, only the corresponding part needs to be disassembled, without disassembling the entire air chamber, effectively improving maintenance efficiency and reducing maintenance costs.

[0051] The air inlet 3 is located on the first part 21, while the heating chamber 6 and the air outlet 4 are located on the second part 22. This layout clearly delineates the areas for air intake, heating, and exhaust, which helps optimize the airflow path within the air chamber and ensures that the air can complete the process from intake to heating and then to exhaust in an orderly manner.

[0052] The electric heating device 7 has a wiring terminal 71 on its side for connecting to an external power source to realize the conversion of electrical energy into heat energy.

[0053] To facilitate the installation and wiring of the terminal block 71, the heating chamber 6 has a mounting groove 23 extending through its inner and outer sides and top. The mounting groove 23 provides an extension channel for the terminal block 71, allowing it to extend smoothly when the electric heating device 7 is installed, facilitating connection with external lines without the need for complex wiring operations in a closed space, thus reducing the installation difficulty.

[0054] The first part 21 is provided with a connector strip 24 that is adapted to and plugs into the mounting slot 23 to close the mounting slot 23. After the electric heating device 7 is installed and the wiring is connected, the first part 21 is connected to the second part 22, and the connector strip 24 is inserted into the mounting slot 23, which can effectively seal the mounting slot 23, prevent air from leaking out of the mounting slot 23, and ensure that air can only flow through the ventilation holes on the electric heating device 7, thus maintaining the stability of air flow and heating efficiency in the air chamber.

[0055] The inner wall of the heating chamber 6 is provided with a support portion 25, and the first part 21 is provided with a downwardly extending limiting portion 26, which together constitute the upper and lower limiting structure for the electric heating device 7. The support portion 25 is located below the electric heating device 7, providing support for the electric heating device 7, bearing the weight of the electric heating device 7, and preventing it from falling downwards under the action of gravity. The limiting portion 26 is located above the electric heating device 7, preventing the electric heating device 7 from moving upwards, and avoiding upward displacement of the electric heating device 7 due to vibration generated by the operation of the fan or other external forces. Through the limiting effect of the support portion 25 and the limiting portion 26 on the upper and lower sides of the electric heating device 7, the electric heating device 7 can be stably installed without the use of traditional fasteners such as screws. This screwless fixing method not only simplifies the installation steps, saves installation time and labor costs, but also reduces the instability of the electric heating device 7 that may be caused by problems such as loose screws, and improves the reliability and stability of the overall structure of the hand dryer. At the same time, this design makes the disassembly and replacement of the electric heating device 7 more convenient, facilitating later maintenance and repair work.

[0056] An air inlet 3 is connected to a ring-shaped circuit board 8, which is coaxial with the air inlet 3 and spaced vertically. The ring-shaped circuit board 8 provides a stable power transmission and signal control path for components such as the fan 5 located near the air inlet. The ring structure allows for a more efficient circuit layout within a limited space, resulting in neater wiring, reduced interference between lines, and improved circuit stability and reliability. Furthermore, the spaced-out arrangement prevents direct contact between the circuit board 8 and the air inlet.

[0057] The ring-shaped circuit board is coaxially positioned with the air inlet, minimizing obstruction to airflow. Because its ring structure matches the shape of the air inlet, air can flow smoothly through the space around the circuit board when entering the inlet, without creating significant eddies or airflow turbulence. This ensures efficient air intake, allowing the hand dryer to continuously and stably draw in outside air, providing a sufficient air supply for subsequent heating and ventilation processes.

[0058] A sensor 11 is located on the lower side of the outer casing 1. This is a key component for the automated control of the hand dryer. The sensor 11 typically employs infrared or capacitive sensing technologies. When a user places their hand under the hand dryer, the sensor 11 quickly detects the hand's presence and converts the detection signal into an electrical signal, which is then transmitted to the control system. Upon receiving the signal, the control system automatically activates the fan 5 and the electric heating device 7, causing the hand dryer to begin operating and blowing hot air to dry the hands. When the user removes their hand, the sensor 11 detects the hand's departure, and the control system automatically shuts off the fan and the electric heating device, stopping the hand dryer from working.

[0059] The outer casing 1 includes a base plate 12 and a cover 13, with the air chamber 2 fixedly connected to the base plate 12. This structural design provides a fundamental guarantee for the overall assembly and performance of the hand dryer. The base plate 12, as the bottom support component of the hand dryer, serves to fix the air chamber 2 and other internal components. Its robust structure ensures the stability of the hand dryer during installation and use, preventing displacement or damage to internal components due to external forces. Simultaneously, the base plate 12 can also be provided with mounting holes and other structures to facilitate the fixed connection of the hand dryer to a mounting wall or other supporting surface, ensuring that the hand dryer will not shake or fall during use.

[0060] The cover 13 covers the hand dryer, protecting internal components such as the fan 5, electric heating device 7, and ring circuit board. It prevents external dust, moisture, and other impurities from entering the hand dryer, avoiding damage to electrical components and mechanical parts, and extending the hand dryer's lifespan. Furthermore, the cover 13's design allows it to work in conjunction with the base plate 12 to form a relatively enclosed space, optimizing airflow within the hand dryer, reducing air leakage, and improving its efficiency. The separate design of the base plate 12 and cover 13 also facilitates inspection, repair, and replacement of internal components during installation and maintenance, reducing maintenance difficulty and costs.

[0061] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hand dryer comprising a housing, characterised in that: The outer casing contains a wind chamber with an air inlet at the top and an air outlet at the bottom. The diameter of the wind chamber gradually decreases from the middle to the top and bottom. A fan is installed at the air inlet, and a heating chamber is located in the middle of the wind chamber, which contains an electric heating device.

2. A hand dryer according to claim 1, wherein: The electric heating device is adapted to the heating chamber, and several ventilation holes are distributed on the electric heating device, penetrating its upper and lower sides.

3. A hand dryer according to claim 2, wherein: The air chamber is formed by connecting the first part and the second part vertically. The air inlet is located on the first part, and the heating chamber and the air outlet are located on the second part. The side of the electric heating device is provided with wiring terminals. The side wall of the heating chamber is provided with a mounting groove that runs through its inner and outer sides and the top side. The first part is provided with a plug strip that is adapted to the mounting groove to close the mounting groove.

4. A hand dryer according to claim 3, wherein: The inner wall of the heating chamber is provided with a support part, and the first part is provided with a downwardly extending restriction part. The restriction part and the support part restrict the vertical movement of the electric heating device on the upper and lower sides of the electric heating device.

5. A hand dryer according to claim 1, wherein: The air inlet is connected to a ring-shaped circuit board, which is coaxial with the air inlet and spaced vertically.

6. A hand dryer according to claim 1, wherein: The lower side of the outer casing is provided with an opening that corresponds to the air outlet.

7. A hand dryer according to claim 1, wherein: The lower side of the outer casing is provided with an air inlet, and the inner side of the air inlet is provided with a filter screen.

8. A hand dryer according to claim 1, wherein: A sensing device is provided on the lower side of the outer casing.

9. A hand dryer according to claim 1, wherein: The outer casing includes a base plate and a cover, with the air chamber fixedly connected to the base plate.

10. A hand dryer according to claim 3, wherein: The first and second parts are fixedly connected by screws.

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