Description:
FIELD OF INVENTION

The present invention relates to bladeless fan. More particularly, the present invention discloses a new concept of bladeless fan including high air flow throw using double coanda effect with no air separation zone concept, also reduce acoustic noise.

BACKGROUND ART

In the market, one can commonly find fans with blades, such as ceiling fans, tower fans, and table fans. These fans all have visible blades or blowers for circulating air. However, the presence of blades in these fans results in turbulent airflow, which can lead to an uncomfortable experience for consumers seated nearby. Additionally, due to this turbulent airflow path, these fans have limited air throw range and tend to produce high noise levels, primarily caused by the axial blades chopping through the air and secondary turbulent air flow path where air is collided with each other. Blower-type fans offer reduced turbulence but still lack completely smooth and laminar airflow path, and they tend to be less efficient.

Coanda Effect: A moving stream of fluid in contact with a curved surface will tend to follow the curvature of the surface rather than continue traveling in a straight line and when it follows curved surface, fluid velocity is increased and pressure on that surface is reduced .

The conventional fans currently available on the market feature visible blades, which give rise to several issues. These problems include disruptive turbulence in the airflow, causing discomfort to users, as well as substantial noise generated by the blades cutting through the air. Moreover, bladed tower/table fans pose safety concerns, with instances of children or individuals sustaining finger injuries. Additionally, bladed fans tend to accumulate visible dust on their blades. In order to address all of these challenges, we have introduced the non-visible bladed fan system.

In the present innovation, the inventors have introduced a novel fan concept that eliminates the need for visible rotating parts like blades. The entire fan appears as a stationary sub assembly with no external rotating components. This fan delivers a smooth and quiet airflow experience and ensures complete child safety, as it doesn't have any externally visible rotating parts, also with Airflow Enhancement Technology.

Generally, in prior art search, there are mainly two type of air delivery system in bladeless fan:

1. As shown in figure 1, the opening of air is behind and using coanda science for multiplying the air flow so air flow at some distance from fan is more than air inlet of fan. (Coanda effect is well known science which is used in many areas like airfoil wing of airplane)

2. As shown in figure 2, the opening of air is front side. In this type, no air multiplying is happened so that air flow at some distance from fan is equal to air inlet of fan.

In the prior art, there is provided a Korean application KR101320980B1 discloses a fan assembly for creating an air current is described. There is provided a bladeless fan assembly comprising a nozzle mounted on a base housing means for creating an air flow through the nozzle. The nozzle comprises an interior passage for receiving the air flow from the base and a mouth through which the air flow is emitted. The nozzle extends substantially orthogonally about an axis to define an opening through which air from outside the fan assembly is drawn by the air flow emitted from the mouth. The fan assembly has a height extending from the end of the base (16) remote from the nozzle to the end of the nozzle remote from the base and a width perpendicular to the height both the height and the width being perpendicular to the axis so that width of the base is no more than 75% the width of the nozzle. This arrangement creates a fan assembly with a compact structure.

In another prior art, an US specification US8529226B2 discloses a bladeless air fan includes a host and an airflow guiding frame. The host divides into a housing section to hold an airflow generator and a pivoting section to include two first pivoting portions. The airflow generator is connected to an airflow guiding manifold extended from the housing section to the pivoting section. The airflow guiding frame includes an air discharging portion and an airflow guiding passage and two second pivoting portions being annular to form two air intake ports communicating with the airflow guiding passage. The second pivoting portions are rotatably coupled with the first pivoting portions such that the airflow guiding passage communicates with the airflow guiding manifold. The air discharging portion encircles an airflow passage being formed at an inner diameter allowing the housing section to pass through to enlarge the range of the second pivoting portions rotating against the first pivoting portions.

SUMMARY OF INVENTION

The non-visible bladed fan system consists of two sub-assemblies. The first sub-assembly, located in the lower section, is known as the dynamic system, which contains a rotating sub assembly similar to an impeller that draws air into the fan. Subsequently, the air is directed through the second sub-assembly, referred to as the air delivery sub assembly or tower. Within this sub assembly, the air travels through a hollow area before emerging from the air delivery system through a small nozzle-like structure.

The air delivery sub assembly (tower) features a distinctive curved design intended to optimize air delivery. As the air transitions from the spacious interior of the tower to the narrow nozzle area which is works like opening, its velocity increases in accordance with the principle of continuity. The high-velocity air then passes through the convex section of the air delivery sub assembly, creating a low-pressure zone near the air delivery system, as explained by Bernoulli's principle. This pressure gradient near the tower, in relation to the surrounding air, causes the surrounding air to be drawn toward the tower and mix with the primary airflow, thereby enhancing the overall quantity of air.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

Fig 1 illustrates a Type 1 of bladeless fan with air multiplier as prior art;

Fig 2 illustrates a Type 2 of bladeless fan without air multiplier as prior art;

Fig 3 illustrates bladeless fan comprising two systems: the air delivery sub assembly (tower) and the dynamic sub assembly in accordance with the present invention;

Fig 4 illustrates bladeless fan air delivery sub assembly (tower) in isometric view, in accordance with the present invention;

Fig 5 illustrates bladeless fan air delivery sub assembly (tower) in front view, in accordance with the present invention;

Fig 6 illustrates bladeless fan including air delivery sub assembly, or tower which is a hollow component in accordance with the present invention (section B-B);

Fig 7 illustrates a side-sectional view of the air delivery sub assembly (Tower), in accordance with the present invention (section A-A);
Fig 8 illustrates a top view of the air delivery sub assembly in accordance with the present invention;
Fig 9 illustrates a sectional view (C-C) of the air delivery sub assembly (tower) in accordance with the present invention;

Fig 10 illustrates bladeless fan air delivery sub assembly (tower) where there is no any divider which divide air flow into two stream so that there is not any air turbulation entry side of air delivery duct.in accordance with the present invention;

Fig 11 illustrates bladeless fan air delivery sub assembly (tower) with less amount of acoustic noise due to less air turbulence outside of profile in accordance with the present invention;

Fig 12A illustrates bladeless fan with non-air separation zone with secondary coanda surface in accordance with the present invention;

Fig 12B illustrates bladeless fan air delivery outside surface providing non air separation zone so less turbulence is created and airflow enhance in accordance with the present invention;

Fig 13 illustrates CFD analysis of said bladeless fan in accordance with the present invention;

DETAILED DESCRIPTION

The bladeless fan system can be divided it into two sub assembly: 1. Dynamic sub assembly (responsible to drag surrounding air to inside fan) and 2. Air delivering sub assembly (responsible to deliver air from inside of fan to user with airflow enhancement technology). Here we are talking about dynamic system.

Dynamic sub assembly: -
In bladeless fan, there is not any visible blade which delivers air. In this dynamic sub system who drag the surrounding air inside the air. Dynamic sub assembly is combination of different parts like body, rotating part (impeller), motor and diffuser. Here motor is attached to the rotating part (impeller) at when impeller rotate at high-speed rpm and creating low pressure area near impeller inlet. Due to low pressure area, surrounding air is drag to fan and enter inside fan through body. Then air is entered in rotating part (impeller) and increase air velocity due to rotation of rotating part (impeller). In this way, air kinetic energy is increased. Now air enters to diffuser portion, where this kinetic energy is converted to pressure head. So, air can easily travel to air delivery sub assembly.

The dynamic sub assembly includes:
1. Body with holes (for allowing surrounding air to enter inside fan)
2. Impeller (this part is attached with motor shaft and responsible for creating suction area / low pressure zone, also increase air velocity)
3. Motor body (motor is attached on this body)
4. Motor
5. Diffuser (stationary part, responsible to convert kinetic energy of air to pressure head and distributes smooth air flow to air delivery system)

In impeller we can use different type of impeller like axial, radial, crossflow, blower and mix flow impeller.

In the present invention, air flow multiplier science is occurred, so our invention is directly related to the type 1 bladeless fan as shown in Fig 1, which is a prior art. Here type 2 bladeless fan as shown in Fig 2 is not relevant to our invention.

In Figure 3, the herein disclosed non-visible bladed fan comprises two systems: the air delivery sub assembly (tower) and the dynamic sub assembly. The dynamic sub assembly is responsible for drawing air into the fan and consists of an assembly featuring an impeller, a motor, and a diffuser, similar to standard rotodynamic sub assembly like pumps, blowers, or turbochargers. This dynamic sub assembly is readily available in the market for the purpose of air suction, and its design remains conventional with the only variable being its dimensions, adjusted to meet our specific air flow rate requirements. Therefore, the dynamic sub assembly does not introduce any novel elements; it simply serves as a commonly available system in the market with its primary function being the regulation of air intake according to our specified air flow rate needs.
The second part of our non-visible bladed fan system is the air delivery sub assembly, known as the "tower." This is the novelty of our patent, and it is represented in the isometric view (Figure 4) and front view (Figure 5). The air delivery sub assembly, or tower, is a hollow component, as shown in Figure 6.

Figure 6 provides a cross-sectional view of the air delivery sub assembly, highlighting various components, including the opening area (6), back support wall (1), convex surface responsible for low-pressure generation (Primary Coanda surface) (2), non-air separation surface / Secondary Coanda Surface (3), air expanding surface (4), the interior of the air delivery sub assembly (tower) (7), and the front supporting wall (5). The non-air separation surface/ Secondary Coanda surface (3) serves to reduce the separation of air from air delivery outside surface, less possibility of turbulence zone on surface and enhances the low-pressure zone area, also work as coanda surface which is responsible for attracting surrounding air towards fan. The air expanding surface increases the air flow area, and its angle with the y-axis is approximately 10°-30°. The back supporting wall (1) plays a crucial role in directing surrounding air towards the main air stream in such way which reduced air turbulence when both air surrounding and outlet air of fan is mixing. The dimensions of the profile in the x-direction are around 80-250 mm, while in the y-direction, they span approximately 50-150 mm.

In this design, air is initially drawn in by the dynamic sub assembly, and it then travels through the interior of the air delivery sub assembly, which is hollow. A small opening (labelled as "6") allows the air to exit the air delivery sub assembly, functioning like a nozzle. As the air transitions from a larger area to a smaller one, the air velocity at these opening increases compared to the interior area (7) as per continuity principle. Here the opening area is around 0.5 – 5 mm.

The high-velocity air interacts with the convex surface of the tower, generating a low-pressure zone on that surface, with a pressure reduction ranging from 10-30 pascals due to the high air velocity. This pressure gradient establishes a flow of surrounding air toward our fan from the atmosphere, essentially turning the convex surface into an air attractor. The attracted surrounding air merge with the main air stream, significantly enhancing the overall air flow rate. After that primary coanda surface, we provide secondary coanda surface with non-air separation feature so that air can draw throughout the cross section path and enhance air flow rate by attracting more surrounding air. The enhancement factor which is ratio of total airflow experience by consumer to fan inlet airflow, is approximately 8-20 times.

In Figure 7, we observe a side-sectional view of the air delivery sub assembly, commonly referred to as the "tower." This view reveals the presence of an interior hollow passage (labeled as "8") and air directional vanes (denoted as "9"). The airflow path is designed to allow air to flow directly from the lower dynamic system to the upper section of the tower, where if necessary we can provide the upper stopper (designated as "10") and is deflected by this stopper.

To minimize the impact of air striking the interior surfaces of the air delivery sub assembly (tower) and to reduce turbulence within the tower, air directional vanes have been integrated. These air directional vanes serve the essential function of guiding the airflow in a specific direction, directing it towards the opening and helping to diminish turbulence within the tower.

Figure 8 provides a top view of the air delivery unit (tower. In Figure 9, we have a sectional view (C-C) of the air delivery unit (tower), which reveals the interaction between its various elements.

The air directional vane (labeled as "9") plays a pivotal role in reducing internal turbulence within the tower while simultaneously guiding the airflow in a specific direction. This directional control ensures that the delivered air stream follows a straight path towards the fan, optimizing the fan's performance. Air enters the air delivery unit (tower) from the lower dynamic unit through an inlet cut (denoted as "11"). The assembly area (labeled as "12") of the air delivery unit with the dynamic unit is illustrated in Figure 9, demonstrating how these two key components work together seamlessly to deliver efficient and controlled Airflow.

This design feature enhances the overall efficiency of the non-visible bladed fan system by ensuring a smoother and more controlled airflow path, thus improving the user experience and the performance of the fan. As below there are some advanced features in our bladeless fan: -

1. Less air resistance in air duct: - As shown in figure 10, there is no any divider which divide air flow into two streams inside air delivery duct so that there is not any air turbulation inside of air delivery duct.
2. Less air turbulation in outside of fan: As shown in figure 11, in our invention surrounding air and outlet air of bladeless fan is not merging immediately due to structure so that air turbulence near the air delivery structure is less which enhance air flow rate Also due to outside of air throw, the air delivery range is more than type 1 bladeless fan.
3. Less noise: As shown in figure 11, there is both side air flow is not collided immediately near the air delivery unit so there is less amount of acoustic noise due to less air turbulence outside of profile.
4. Non Air separation zone: In type 1 bladeless fan, there is inclined straight surface after coanda surface, therefore there is air separation which reduced low pressure zone. To solve this problem, we have provided non air separation zone with secondary coanda surface as shown in figure 12A. Due to non-air separation surface, there is less amount of air turbulence near profile. As shown in Fig 12B, if there is air separation happened near profile surrounding air comes to feel free space and created air turbulence. So that there is no air separation which increase low pressure zone area and value. Therefore, Airflow rate is enhanced.

5. Complete utilization of air flow by consumer: As shown in figure 13, this is CFD analysis of our bladeless fan which throw air completely straight to fan so that consumer get complete fan air flow experience. Generally type 1 bladeless fan in prior art search has upward inclined airflow.

6. High Air multiplier: As shown in the figure 12A, our bladeless fan concept, there is two type coanda surface which helps to create low pressure zone. First one is primary coanda surface which is major responsible to create low pressure zone and attract the surrounding air towards fan. Second one is secondary coanda surface which is responsible for two area: 1. Extend low pressure zone (increase low pressure area) to attract more surrounding air and 2. Work as non-air separation zone so that outlet air of fan is stick to the profile of air delivery fan and not create air turbulence. As above reason our bladeless fan concept has more high air multiplier.

Comparison of bladeless fan in prior art V/s present invention
Prior Art Search Our invention
Sr No Specification Type 1 - with air multiplier Type 2 - without air multiplier Version 1 - straight profile
1 Air multiply technology Yes No Yes
2 Air Resistance in air duct High NA Low
3 Air turbulance outside of profile High NA Low
4 Noise High NA Low
5 Air seperation zone Yes NA No
6 Air multiplier surface single NA double
7 Total Air Flow Medium Low High
8 Low Pressure zone Low No Medium
9 fan air utilization not complete Complete complete

Inventive step

In our invention there are some unique points which is different than other prior art search report:
1. No air separation in our invention so air can flow over complete of profile due to non-separation zone.
2. Low pressure zone is high due to double coanda and non-air separation zone.
3. No air resistance inside of air duct due to tower structure.
4. Complete air flow throw utilization due to straight air flow which enhance the consumer experience.
5. Low noise generation due to outside air opening which reduce acoustic noise level (figure 11)
6. More surface available for enhancing aesthetic look as front non function surface like mirror, digital screen, lighting, speaker and many other use case as shown in figure 4.

While the present invention has been described with reference to a specific preferred embodiment, it will be apparent that various modifications and changes could be made to this embodiment without departing from the scope of the invention as hereinafter claimed. The above-mentioned descriptions are provided to serve the purpose of clarifying the aspects of the invention, and it will be apparent to one skilled in the art that they do not serve to limit the scope of the invention. All modifications and improvements have been incorporated herein for the sake of conciseness and readability but are properly within the scope of the present invention.

, Claims:
1. A bladeless fan, includes housing, air intake dynamic sub assembly and air-delivery sub assembly in said housing operably connected with communicative air flow pathway with each other;
wherein the said air intake dynamic sub assembly includes
a. a body with holes configured for allowing surrounding air to enter inside fan;
b. an impeller attached with motor shaft configured for creating suction area / low pressure zone and due to rotation of impeller increasing air velocity;
c. a motor body including a motor is attached on said motor body;
d. a diffuser configured to convert kinetic energy of air to pressure head and give smooth air flow to air delivery sub system;
wherein the said air delivery sub assembly features a distinctive curved design intended to optimize air delivery such that the air transitions from the spacious interior of the tower to the narrow nozzle area, with high-velocity through the convex section of the air delivery sub assembly, creating a low-pressure zone near the air delivery system; and
wherein said air delivery sub assembly is provided with non-air separation zone so air can flow over complete of profile with double coanda impact with non-air separation zone.

2. The bladeless fan as claimed in claim 1, wherein, air is initially drawn in by the dynamic sub assembly, and it then travels through the interior of the air delivery sub assembly, which is hollow; and
wherein a small opening (6) is provided in order to allow the air to exit the air delivery assembly, functioning like a nozzle.

3. The bladeless fan as claimed in claim 1, wherein air intake dynamic sub assembly is configured to provide air transitions from a larger area to a smaller one, such that the air velocity at said opening increases as compared to the interior area (7).

4. The bladeless fan as claimed in claim 3, wherein said air delivery sub assembly includes an opening area (6), back support wall (1), convex surface responsible for low-pressure generation (Primary Coanda surface) (2), non-air separation surface / Secondary Coanda Surface (3), air expanding surface (4), the interior of the air delivery sub assembly (tower) (7), and the front supporting wall (5).

5. The bladeless fan as claimed in claim 4, wherein said non-air separation surface/ Secondary Coanda surface (3) serves to reduce the separation of air from the main air stream and enhances the low-pressure zone area, and work as coanda surface which is responsible for attracting surrounding air towards fan.

6. The bladeless fan as claimed in claim 5, wherein said air expanding surface increases the air flow area, and its angle with the y-axis is approximately 10°-30°.

7. The bladeless fan as claimed in claim 4, wherein said back supporting wall (1) is configured to direct surrounding air towards the main air stream in such way which reduced air turbulence when both air surrounding and outlet air of fan is mixing.

8. The bladeless fan as claimed in claim 4, wherein the dimensions of the said profile in the x-direction are around 80-250 mm, while in the y-direction, and the total span is approximately 50-150 mm.

9. The bladeless fan as claimed in claim 1, wherein said coanda impact profile structure create double impact of air attraction (surrounding air attractor) wherein the first is primary coanda surface which surface is completely reduced the low-pressure zone around the surface and secondary coanda surface function include increase low pressure zone area and eliminate air separation zone.

10. The bladeless fan as claimed in claim 1, wherein said air delivery sub assembly includes presence of an interior hollow passage (8) and air directional vanes (9) in order to allow air to flow directly from the lower dynamic system to the upper section of the tower.

11. The bladeless fan as claimed in claim 1, wherein said double coanda impact with non-air separation zone is configured to lower the acoustic noise and lower air turbulence outside and inside of Air delivery system.