A bladeless ventilation device for limited space

Abstract

The present invention relates to a bladeless ventilation device for a limited space, comprising a fan and a ventilation unit, wherein the ventilation unit forms a circular closed loop with an internal air duct, and is provided with an air inlet, an air outlet and a Coanda surface. The fan is located in the closed loop of the ventilation unit, and drives the fan blades to rotate through a driving member to achieve effective lifting and flow of air. The device utilizes the Coanda effect to change the path of the airflow, and forms different pressure fields in the front and rear areas of the bladeless ventilation device, thereby sucking the rear air through the annular opening to achieve an air multiplication effect. The design of the ventilation unit optimizes the airflow path, reduces the flow resistance, and ensures efficient ventilation. In addition, the components of the present invention adopt a detachable structure, which is easy to maintain and replace. The bladeless ventilation device of the present invention has the advantages of compact structure, low operating noise, high ventilation efficiency, etc., and is suitable for the ventilation needs of power wells, underground tunnels and other limited spaces.

Description

Technical Field

[0001] The invention belongs to the technical field of ventilation, and in particular relates to a bladeless ventilation device used in a limited space. Background Art

[0002] In confined spaces such as underground power wells, poor air circulation often leads to reduced oxygen content, which not only poses a threat to the health of maintenance personnel, but may also cause equipment overheating and the accumulation of harmful gases. In order to ensure the safety of maintenance personnel and the normal operation of equipment, effective ventilation measures must be taken. Traditional ventilation equipment usually uses a blower connected to a wind tube to introduce fresh air from the well cover through a larger diameter wind tube. Although this structure can achieve air flow and exchange to a certain extent, its limitations are also very obvious.

[0003] First, traditional blowers and air cylinder systems occupy a large space, often causing significant spatial obstructions at the wellhead. This not only affects the installation and maintenance of other equipment, but may also limit the effective use of the work area. In addition, although these devices can provide a certain ventilation capacity, in a closed environment, the uniformity and coverage of air flow are often insufficient, resulting in ventilation dead spots in local areas, and the overall air quality cannot be effectively improved. Especially when the equipment is running at high load, the unevenness of air flow may cause equipment overheating and potential safety hazards.

[0004] Secondly, the noise interference generated by traditional blowers during operation may have a negative impact on the working environment of maintenance personnel, affecting work efficiency and safety. In addition, blowers usually require higher energy to drive, which causes greater energy consumption during long-term operation and increases operating costs. Therefore, how to reduce energy consumption and improve ventilation efficiency has become an urgent problem to be solved.

[0005] In addition, the maintenance and overhaul of traditional equipment is often complicated. Due to the layout of the air duct and the installation position of the blower, the maintenance and overhaul of the equipment requires additional manpower and time, which increases the complexity of operation and maintenance. At the same time, the organization and directionality of the airflow are often not effectively controlled in these traditional designs. The instability and turbulence of the airflow not only reduces the ventilation effect, but also may cause secondary pollution. Summary of the invention

[0006] The purpose of the present invention is to provide a bladeless ventilation device for a limited space in order to overcome the defects of the prior art.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The present invention provides a bladeless ventilation device for a limited space, including a circular ventilation device, wherein a plurality of ventilation units evenly arranged in sequence are arranged on the upper surface of the ventilation device, an inner surface of the ventilation device is provided with air outlets interconnected with each other, the ventilation units include a partition, a U-shaped baffle, an inner baffle, an outlet baffle and a fan, the ventilation unit also includes an internal air duct formed by the U-shaped baffle, the inner baffle and the outlet baffle, the partition divides the internal air duct into a U shape, the fan includes a driving part, an air inlet duct, and a plurality of fan blades, the air inlet duct is connected to the outside air, the fan outlet is connected to the internal air duct, the internal air duct is connected to the outlet, the inner baffle is fixedly connected to the U-shaped baffle, and the inner baffle is provided with a Coanda surface at the end of the air outlet.

[0009] Furthermore, the U-shaped baffle includes a left straight plate, a U-shaped plate, and a right straight plate.

[0010] Furthermore, the inner baffle is fixedly connected to the right straight plate.

[0011] Furthermore, the angle between the inner baffle and the extension line of the right straight plate is between 12° and 16°.

[0012] Furthermore, the minimum distance between the upper surface of the outlet baffle at the end of the air outlet and the lower surface of the Coanda surface is between 1.3 mm and 1.5 mm.

[0013] Furthermore, the internal air ducts of the multiple ventilation units that are evenly and sequentially arranged are interconnected.

[0014] Furthermore, the driving member is fixedly connected to the plurality of fan blades.

[0015] Furthermore, the air outlet and the air inlet duct are located on the same side of the ventilation device.

[0016] Furthermore, the outlet baffle is semi-elliptical, and the elliptical opening faces the Coanda surface.

[0017] Furthermore, the outlet baffle is fixedly connected to the partition.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) The present invention solves the problem that the traditional blower and air duct system occupies a large space during the ventilation of underground power wells, causing significant space obstacles and affecting the installation and maintenance of other equipment by setting the ventilation device in a circular shape. The circular ring design can realize the ventilation process of underground power wells, facilitate the entry and exit of personnel and tools, and improve the efficiency of equipment installation and maintenance.

[0020] (2) The present invention configures the ventilation device to be annular and arranges the air outlet and the air inlet duct on the same side. The air outlet on the inner side of the ventilation device is designed to be upward, thereby driving the upward flow of the intermediate airflow, thereby achieving the removal of polluted gases from underground power wells and significantly improving the ventilation efficiency. This solves the problem in the prior art that the instability and turbulence of the airflow not only reduces the ventilation effect but also causes secondary pollution.

[0021] (3) The present invention sets a certain angle between the inner baffle and the extension line of the right straight plate and the Coanda surface, thereby enhancing the acceleration and injection effect of the airflow through the attachment and flow change of the airflow, and utilizing the Coanda effect to improve the ventilation efficiency.

[0022] (4) The present invention sets the partition and the outlet baffle in a semi-elliptical shape. The partition divides the internal air duct into a U-shape, and the elliptical opening faces the coanda surface, so that the air inlet and the air outlet are located on one side, and the gas flow direction of the air inlet is consistent with the gas flow direction of the air outlet, which effectively optimizes the flow path of the airflow, so that the airflow forms a relatively smooth flow inside the equipment, thereby improving the ventilation efficiency. In addition, this design helps to reduce the reverse disturbance of the airflow, reduce energy loss, and ensure that the overall operation of the ventilation system is smoother. Since the air inlet and the air outlet are located on the same side and the gas flow direction is consistent, it helps to avoid the phenomenon of air backflow, reduce the poor air circulation and accumulation, and ensure better gas exchange and ventilation effects.

[0023] (5) By connecting the various internal air ducts, the system can more effectively guide the airflow and reduce the resistance loss of air between the various internal air ducts. In this way, the air flow driven by the fan can flow more smoothly, thereby improving the working efficiency of the entire ventilation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A front view of a wellhead bladeless blower provided by an example of the present invention;

[0025] Figure 2 A three-dimensional schematic diagram of a wellhead bladeless blower provided by an example of the present invention;

[0026] Figure 3 for Figure 1 The cross-sectional schematic diagram of the wellhead bladeless fan along the AA line is shown;

[0027] Figure 4 for Figure 3 A partial enlarged schematic diagram of the middle area Ⅰ;

[0028] Figure 5 A front view of a fan module assembly provided by an example of the present invention;

[0029] Figure 6A three-dimensional schematic diagram of a fan module group provided by an example of the present invention;

[0030] Figure 7 A schematic diagram of the effect of a ventilation device provided by an embodiment of the present invention;

[0031] The reference numerals in the figure are: 100, ventilation device, 101, ventilation unit, 102, air outlet, 103, air inlet, 104, internal air duct, 105, Coanda surface, 106, partition, 107, U-shaped baffle, 108, inner baffle, 109, outlet baffle, 110, right straight plate, 201, fan blade, 202, driving member, 203, air inlet duct. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] Example 1.

[0034] This embodiment provides a bladeless ventilation device for a limited space, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6As shown, the annular ventilation device 100 is provided with a plurality of ventilation units 101 evenly arranged in sequence on the upper surface of the ventilation device 100, and the inner surface of the ventilation device 100 is provided with air outlets 102 that are interconnected. The ventilation unit 101 includes a partition 106, a U-shaped baffle 107, an inner baffle 108, an outlet baffle 109 and a fan, and the ventilation unit 101 also includes a U-shaped baffle 107, an inner baffle 108 and an outlet baffle 109 formed between the baffle 109. The internal air duct 104 is divided into a left air duct and a right air duct by a partition 106. The left air duct and the right air duct are connected to each other. The fan includes a driving member 202, an air inlet air duct 203, and a plurality of fan blades 201. The air inlet air duct 203 is connected to the outside air. The fan outlet is connected to the internal air duct 104. The inner baffle 108 is fixedly connected to the U-shaped baffle 107. The inner baffle 108 is located at the end of the air outlet 102 and is provided with a Coanda surface 105. The U-shaped baffle 107 includes a left straight plate, a U-shaped plate, and a right straight plate 110. The inner baffle 108 is fixedly connected to the right straight plate 110. The angle between the extension lines of the inner baffle 108 and the right straight plate 110 is between 12° and 16°. The minimum distance between the upper surface of the outlet baffle 109 located at the end of the air outlet 102 and the lower surface of the Coanda surface 105 is between 1.3mm and 1.5mm. The internal air ducts 104 of the plurality of ventilation units 101 are interconnected. The driving member 202 is fixedly connected to the plurality of fan blades 201. The air outlet 102 and the air inlet air duct 203 are located on the same side of the ventilation device 100. The outlet baffle 109 is semi-elliptical, and the elliptical opening faces the Coanda surface 105. The outlet baffle 109 is fixedly connected to the partition 106.

[0035] The ventilation unit 101 is the core part of the whole device, and has an internal air duct 104, an air inlet 103, an air outlet 102 and a Coanda surface 105. The ventilation unit 101 is connected to the fan through the air inlet 103, and the internal air duct 104 of the ventilation unit is connected to the air outlet of the fan. The ventilation unit 101 is responsible for guiding the air flow, using the Coanda effect to enhance the output and intake of the air flow, forming a high-pressure air flow, and improving the ventilation efficiency.

[0036] The fan includes a plurality of blades 201, a driving member 202 and an air inlet duct 203. The blades 201 of the fan are connected to the driving member 202 through a bearing or a connecting rod, and the driving member 202 is connected to the air inlet 103 through the air inlet duct 203. The fan is responsible for generating airflow, increasing air pressure through the rotation of the blades, sucking in external air and sending it into the internal air duct 104 of the ventilation unit.

[0037] Air inlet 103 is the entrance for air to enter the system. Air inlet 103 is connected to ventilation unit 101, located at the front end of the ventilation unit, and directly connected to the fan. Air inlet 103 is responsible for introducing external air to provide a flowing air source for the system.

[0038] The air outlet 102 is the outlet of the ventilation unit 101, from which the air is ejected. The air outlet 102 is connected to the internal air duct 104 of the ventilation unit 101 to form an outlet for the air flow. The air outlet 102 is responsible for ejecting the compressed and accelerated air flow into the external environment to enhance the ventilation effect.

[0039] Coanda surface 105, which is a part of the interior of ventilation unit 101 and is designed to guide airflow. Coanda surface 105 is connected to air outlet 102 of ventilation unit 101 to form a channel for fluid flow. Coanda surface 105 enhances the acceleration and injection effect of airflow through the attachment and flow change of airflow, and improves ventilation efficiency by using Coanda effect.

[0040] The driving member 202 is the power source of the fan, which is usually an electric motor or other driving mechanism. The driving member 202 is connected to the fan blades 201 through a mechanical connection and directly drives the fan blades to rotate. The driving member 202 is responsible for providing energy to rotate the fan blades, thereby generating airflow and increasing air pressure.

[0041] Internal air duct 104 is a passage inside the ventilation unit 101 for guiding airflow. The internal air duct 104 is connected to the air inlet 103 and the air outlet 102 of the ventilation unit. The internal air duct 104 is responsible for guiding the flow of air with increased air pressure to smoothly pass through the ventilation unit and increase the speed of the airflow.

[0042] In the embodiment of the present invention, the design of the ventilation unit not only focuses on the basic airflow guidance, but also takes into account the optimization of fluid mechanics. The internal air duct of the ventilation unit adopts a streamlined design to reduce the turbulence and pressure loss that may be generated during the flow of the airflow. This design helps to ensure that the airflow can flow smoothly inside the ventilation unit, thereby maximizing the speed and output efficiency of the airflow.

[0043] The fan blade design adopts the principle of efficient aerodynamics. The shape and inclination of the blade are carefully calculated to achieve the best airflow lifting effect. The material selection of each blade is also crucial. Lightweight and high-strength composite materials are usually used to ensure structural stability at high speeds.

[0044] In the selection of the drive, the present invention takes into account energy efficiency and noise level, and may use a brushless DC motor, which has high energy efficiency and low noise during operation, which contributes to the quiet effect of the overall device. In addition, the control system of the drive can be intelligently adjusted according to environmental requirements, such as adjusting the wind speed in real time according to temperature, humidity or other sensor data to achieve higher energy saving effects.

[0045] The design of the Coanda surface is not only to induce airflow, but also to increase the airflow's adhesion ability by optimizing its curvature and material. The effective use of the Coanda effect can not only enhance the speed of the jet airflow, but also improve the distribution characteristics of the airflow, ensuring a more uniform air flow, thereby improving the overall ventilation efficiency.

[0046] The opening design of the ventilation unit has also been carefully considered. The shape and position of the opening can effectively balance the pressure at the nozzle and the inflow of surrounding air, forming an optimal low-pressure area, thereby increasing the amount of air intake. This design ensures that the device can still work stably under different environmental conditions.

[0047] In order to achieve higher flexibility of the device, the connection part between the ventilation unit and the fan is designed to be a detachable structure for easy maintenance and replacement.

[0048] Example 2.

[0049] The present embodiment provides a bladeless ventilation device for a limited space, comprising: a ventilation device 100, the ventilation device 100 comprises a ventilation unit 101, the ventilation unit 101 is the core component of the present invention, an air duct is arranged inside, and is connected to an air inlet 103 and an air outlet 102. The design of the ventilation unit 101 adopts a U-shaped closed loop structure to form a closed internal air duct 104. This design not only enhances the guiding property of the airflow, but also reduces the pressure loss of the airflow, thereby ensuring the smoothness of the air flow in the air duct.

[0050] Coanda surface 105, the air outlet 102 of the ventilation unit 101 is connected to the outer wall through the Coanda surface 105, and the purpose of the design of the Coanda surface 105 is to guide the airflow to flow along the surface by using the Coanda effect. Under the action of the Coanda surface 105, the airflow can form a vortex effect, increase the airflow of the air outlet 102, and improve the ventilation efficiency. The Coanda surface 105 can also effectively reduce the interference of the airflow and reduce the noise.

[0051] The fans each include a drive 202, a fan blade 201 and an air duct at an air inlet 103. The drive 202 is responsible for driving the fan blade 201 to rotate, thereby promoting the air flow in the air duct. Unlike traditional fans, the bladeless design eliminates the disturbance of the fan blade 201 to the air flow, making the air flow more stable, reducing noise and improving ventilation effect.

[0052] Air inlet 103: The ventilation unit 101 is provided with a plurality of air inlets 103, and the arrangement of these air inlets 103 ensures that the external air can smoothly enter the internal air duct 104, providing sufficient air supply for the fan module group. The design of the air inlet 103 takes into account the guidance of the air flow, so that the air entering the air duct can be fully accelerated when passing through the fan module group, forming a strong ventilation effect.

[0053] The ventilation unit 101 is composed of a U-shaped baffle 107 and a partition 106. The U-shaped baffle 107 is provided with a plurality of air inlets 103. The partition 106 extends from one end of the U-shaped baffle 107 to divide the internal air duct 104 into a U shape. This partition design effectively optimizes the flow path of the airflow and improves the overall ventilation efficiency.

[0054] Material, the outer wall material of the ventilation unit 101 is made of rubber, which has good flexibility and wear resistance, can adapt to different environmental conditions, and ensure long-term stable operation. The use of rubber material can also reduce vibration and noise and improve the overall performance of the device.

[0055] In order to ensure that the ventilation device 100 can be firmly placed at the wellhead of the power well, the outer diameter of the ventilation device 100 is designed to be 1 cm to 2 cm larger than the inner diameter of the wellhead. This design ensures the fixation of the ventilation unit 101 at the wellhead, avoids air leakage caused by looseness, and thus improves the stability and safety of ventilation.

[0056] The connection form between the components of the bladeless ventilation device of the present invention is scientifically designed to ensure the efficient operation and stability of the device. The ventilation unit 101 is connected to the fan module group through an interface to form a tight whole. An air duct is provided inside the ventilation unit 101, and the air inlet 103 is connected to the air outlet 102 of the ventilation unit 101, and air flows therein.

[0057] The fan module group is composed of multiple components, including a driving member 202, a fan blade 201, and an air duct of the air inlet 103. The driving member 202 is fixed to the bottom of the air duct of the air inlet 103 by a bracket or a connecting rod to ensure stability during operation. The fan blade 201 is connected to the driving member 202 through a bearing, so that the driving member 202 can effectively drive the fan blade 201 to rotate, thereby generating a strong airflow.

[0058] The air inlet 103 is connected to the ventilation unit 101 through a flange or a sealing ring to form an airtight interface to ensure that the airflow does not leak. The design of the ventilation unit 101 takes into account the compatibility with the external environment, so that the outer diameter of the ventilation unit 101 is 1 to 2 cm larger than the inner diameter of the wellhead, so that it can be stably placed at the wellhead of the power well.

[0059] In addition, the space formed by the Coanda surface 105 inside the ventilation unit 101 and the air outlet 102 is designed at an appropriate angle so that the airflow can be smoothly ejected from the air outlet 102, while forming an effect of attracting external air, further enhancing the ventilation effect.

[0060] The entire system is connected by fasteners and joints to ensure that each component will not loosen or move during operation, and it is also convenient for later maintenance and replacement. This integrated design not only improves ventilation efficiency, but also improves the overall stability and reliability of the device.

[0061] The ventilation efficiency is significantly improved. Through the optimized design of the ventilation unit 101 and the fan module group, the flow of air in the ventilation unit 101 is enhanced, thereby effectively improving the air exchange rate and solving the problem of poor air flow in a confined space of traditional equipment.

[0062] The noise level is greatly reduced. Due to the bladeless design and streamlined ventilation unit 101 structure, the airflow output is smoother, significantly reducing the noise generated during operation, creating a quieter working environment, suitable for use in places where quiet operation is required.

[0063] The floor space is effectively reduced. Traditional equipment usually requires a large space, but the compact design of the present invention significantly reduces its floor space, making it easy to flexibly install in an environment with limited space and improving adaptability.

[0064] The design complexity is reduced. Compared with the traditional ventilation equipment, the structure of the present invention is simpler, the connection between the components is clear, and the maintenance and operation are more convenient, thereby reducing potential failure points and improving the reliability of the equipment.

[0065] Wide applicability. Due to the efficient airflow control and design flexibility of the bladeless fan, the present invention can adapt to a variety of closed environments, provide safe and effective ventilation solutions, and meet the needs of different places. These beneficial effects make the present invention have important application value in the field of ventilation technology.

[0066] This embodiment takes into account the geometric shape of the ventilation device 100, the air flow velocity at the air outlet, and the influence of the Coanda effect on the air flow. According to the basic principles of gas dynamics, the design of the ventilation device 100 has an important influence on the fluid flow. Assume that the diameter of the internal air duct 104 of the ventilation device 100 is D , the width of the air outlet is d (i.e. the minimum distance between the inner surface of the outer wall and the Coanda surface). According to the continuity equation, the gas flow rate Q 1 can be expressed as: ,in, A is the cross-sectional area of ​​the airflow, v is the air flow velocity. The air flow cross-sectional area in the ventilation device 100 can be expressed as , and the air flow cross-sectional area of ​​the outlet can be approximately expressed as ,in L is the annular length of the air outlet.

[0067] The airflow in the ventilation device 100 is analyzed by the Bernoulli equation. Assuming that the airflow in the ventilation device 100 is incompressible and flows in a steady state, the pressure difference before and after the flow can be expressed as: .

[0068] At the inlet of the ventilation device 100, the velocity of the air flow v 1 is lower, and at the air outlet, the air flow speed v 2 is higher. As the airflow passes through the ventilation device 100, the pressure P 1 down, air flow speed v 2 Rapidly increase, forming high-pressure airflow.

[0069] In order to evaluate the influence of the Coanda effect on the airflow, the outside air is set to pass through the opening A open According to the law of conservation of momentum of airflow, the low-pressure area formed by the high-pressure airflow generated by the air outlet of the ventilation device 100 P low It can be expressed as: ,in, is the pressure difference formed by the jet flow. Figure 7 As shown, by combining the continuity equation and momentum equation, the entrained air flow rate can be derived Q 2 Relationship with the airflow at the air outlet of the ventilation device 100: ,in, k is the gain factor of the Coanda effect, which indicates the efficiency of external air being sucked in.

[0070] In summary, the total ventilation volume of the ventilation device is: Through the above mathematical derivation, the airflow characteristics of the bladeless ventilation device under different working conditions can be analyzed, and the design of the ventilation device 100 can be optimized to improve the ventilation efficiency and airflow multiplication effect. In addition, the above theoretical derivation is verified by numerical simulation, which further supports the practical application of the present invention.

[0071] This embodiment analyzes the airflow dynamics characteristics of the bladeless ventilation device through a mathematical model and provides a systematic evaluation method to ensure its effectiveness and reliability in practical applications.

[0072] In general, the present invention ensures efficient ventilation capacity of the device in a limited space by optimizing the design and mutual coordination of various components, while reducing noise and floor space, improving user experience and practicality of the equipment.

[0073] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A bladeless ventilation device for a limited space, characterized in that: The invention comprises a circular ventilation device (100), wherein the upper surface of the ventilation device (100) is provided with a plurality of ventilation units (101) evenly arranged in sequence, the inner surface of the ventilation device (100) is provided with air outlets (102) that are interconnected, the ventilation unit (101) comprises a partition plate (106), a U-shaped baffle plate (107), an inner baffle plate (108), an outlet baffle plate (109) and a fan, and the ventilation unit (101) further comprises an internal air flow formed between the U-shaped baffle plate (107), the inner baffle plate (108) and the outlet baffle plate (109). The fan comprises a driving member (202), an air inlet duct (203), and a plurality of fan blades (201); the air inlet duct (203) is in communication with the outside air; the fan outlet is in communication with the internal air duct (104); the internal air duct (104) is in communication with the air outlet (102); an inner baffle (108) is fixedly connected to the U-shaped baffle (107); and the inner baffle (108) is provided with a coanda surface (105) at the end of the air outlet (102); The U-shaped baffle (107) comprises a left straight plate, a U-shaped plate, and a right straight plate (110); The inner baffle plate (108) is fixedly connected to the right straight plate (110); The angle between the extension lines of the inner baffle plate (108) and the right straight plate (110) is between 12° and 16°; The air outlet (102) and the air inlet duct (203) are located on the same side of the ventilation device (100).

2. A bladeless ventilation device for a limited space according to claim 1, characterized in that: The minimum distance between the upper surface of the outlet baffle (109) located at the end of the air outlet (102) and the lower surface of the Coanda surface (105) is between 1.3 mm and 1.5 mm.

3. A bladeless ventilation device for a limited space according to claim 1, characterized in that: The internal air ducts (104) of the plurality of ventilation units (101) arranged evenly and sequentially are interconnected.

4. A bladeless ventilation device for a limited space according to claim 1, characterized in that: The driving member (202) is fixedly connected to the plurality of fan blades (201).

5. A bladeless ventilation device for a limited space according to claim 1, characterized in that: The outlet baffle (109) is semi-elliptical, with the elliptical opening facing the Coanda surface (105).

6. A bladeless ventilation device for a limited space according to claim 1, characterized in that: The outlet baffle (109) is fixedly connected to the partition (106).

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