Description:
FIELD OF INVENTION

The present application is a Patent of Addition to co-pending application No. 202421013770 of 26.02.2024.
The present invention relates to bladeless fan. More particularly, the present invention discloses a new concept of bladeless fan including air delivery unit (tower) which features a distinctive curved design intended to optimize air delivery 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 unit 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 unit or tower. Within this unit, the air travels through a hollow area before emerging from the air delivery system through a small nozzle-like structure.

The air delivery unit (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, its velocity increases in accordance with the principle of continuity. The high-velocity air then passes through the convex section of the air delivery unit, 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 a side-sectional view of the air delivery sub assembly (Tower), in accordance with the present invention (section A-A);

Fig 7 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 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 13A illustrates CFD analysis of said bladeless fan in accordance with the present invention;

Fig 13B 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 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, our non-visible bladed fan comprises two systems: the air delivery unit (tower) and the dynamic unit. The dynamic unit 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 units like pumps, blowers, or turbochargers. This dynamic unit 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 unit 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 is the air delivery unit, known as the "tower." This tower component represents the novelty of our patented design. A schematic isometric view of the tower is presented in Figure 4, while Figure 5 provides a front view of the tower. The air delivery unit, or tower, is a hollow structure, as illustrated in Figure 7. Initially, air is drawn into the fan by the dynamic unit, after which it travels through the interior path of the air delivery unit, which is hollow. Unlike a straight structure, our tower features a curved shape, as depicted in Figure 4. This curvature serves a dual purpose: it promotes a more even air flow inside the air delivery unit and increases the velocity of the outlet air. This heightened velocity contributes to air enhancement, as it draws surrounding air toward the air delivery unit, thereby increasing overall air delivery.
Figure 7 reveals a small opening (labeled as "6") within the cross-section of the air delivery unit, serving as an outlet for the air. These opening functions much like a nozzle since the air transitions from a larger area (inside the air delivery unit) to a smaller one (the nozzle). Consequently, the air velocity at this opening (6) increases by 8-10 times compared to the interior area (7) of the unit. Here the opening area is around 0.5 – 5 mm.

The high-velocity air interacts with the convex surface (primary coanda surface) of the tower, generating a low-pressure zone on that surface, in accordance with Bernoulli's principle. This pressure reduction on the convex surface ranges from 15-30 pascals due to the high air velocity. Consequently, a pressure gradient is established, with low pressure on the convex surface and atmospheric pressure in the surrounding area. This gradient causes the surrounding air to be drawn toward our fan, essentially turning the convex surface into an air attractor. This attracted air mixes with the main airflow, 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, in comparison to the initially sucked-in air (inlet air), is approximately 12-25 times.

In Figure 7, the cross-sectional area of the air delivery unit is shown, featuring the opening area (6), the back support wall (1), the convex surface responsible for low-pressure generation (2), the secondary coanda surface with non-air separation feature (3), the air-expanding position (4), the interior of the air delivery unit (tower) (7), and the front supporting wall (5). The back support wall (1) plays a critical role in guiding surrounding air toward the main air stream. The non-air separation surface (3) minimizes the separation of air from the main air stream, consequently expanding the low-pressure zone area. The air-expanding surface serves to increase the air flow area, with an angle of approximately 10°-20° relative to the y-axis.

The profile dimensions in the x-direction range from 80-250 mm, while in the y-direction, they span approximately 50-150 mm.

In Figure 6, we present a side section view of the air delivery unit, or tower, revealing its interior components. Within this hollow passage (labeled as "8"), air travels directly from the lower dynamic system to the upper section, where it strikes the upper stopper (denoted as "10"). To mitigate the impact of air hitting the interior of the air delivery unit (tower) and reduce turbulence within it, we have incorporated air directional vanes (identified as "9"). These vanes provide a specific direction to the air, guiding it towards the opening and minimizing turbulence inside the tower.

Figure 8 offers a top view of the air delivery unit (tower), while Figure 9 provides a sectional view of the same. The air directional vanes (9) play a crucial role in reducing turbulence within the unit, directing the airflow outward, and maintaining a straight path for the delivered air, ensuring it flows directly to the fan. Air enters the air delivery unit (tower) through the inlet cut (labelled as "11") from the lower dynamic unit. Figure 9 also illustrates the assembly area (12) of the air delivery unit in conjunction with the dynamic unit.

In Figure 9, the air delivery unit system features a curved structure where the cross-sectional area of the air delivery unit decreases from the bottom of the tower (labelled as "13") to the midpoint (denoted as "14"). Subsequently, the cross-sectional area of the air delivery unit increases again from the midpoint (14) to the top of the tower (15). This curved Profile design offers two significant advantages over straight design:
1. Reduced Air Flow Turbulence: The curvature of the air delivery unit helps minimize turbulence within the tower. By gradually decreasing and then increasing the cross-sectional area, the airflow experiences a smoother transition, resulting in reduced turbulence.
2. Enhanced Air Delivery: The design maximizes air velocity at the midpoint (14) of the air delivery unit. This increased velocity enhances air delivery in the middle portion of the tower, providing consumers with a heightened airflow experience.
Overall, this curved structure not only reduces turbulence but also optimizes air velocity, contributing to improved air delivery and consumer satisfaction. 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 in research as shown in figure1.
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 (fig 1), 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 13A and 13B, 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 (fig 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.

7. Focus Airflow in middle of fan:- As depicted in Figure 9, the profile of the air delivery unit exhibits a curved shape. From the bottom, labeled as 13, to the midplane, labeled as 14, the cross-section decreases, while from the midplane, labeled as 14, to the top, labeled as 15, the cross-section increases. This curved profile results in higher air velocity at the midpoint of the fan outlet compared to other areas, enhancing the airflow in the central portion. Additionally, the curved profile minimizes turbulence across the entire profile, creating more low-pressure zones that attract surrounding air towards the fan. Consequently, the overall airflow of the fan is amplified. This design approach enables us to achieve a higher airflow rate while concentrating the airflow towards the center of the fan (Fig 13A and 13B).
In summary, our non-visible bladed fan system addresses various design aspects, such as reduced air resistance, straight airflow, compactness, and the absence of air separation, to offer improved performance and user experience compared to other prior art search patent .

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 impact with non-air separation zone.
3. No air resistance inside of air duct due to tower structure.
4. Low noise generation due to outside air opening which reduce acoustic noise level (figure 11)
5. Complete feasibility to use variable cross section with surrounding air attractor feature with focused air flow at center of fan.
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.
Overall, these points highlight the unique features and benefits of our non-visible bladed fan system, making it an attractive option for consumers seeking improved air circulation and comfort.

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 – curved 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

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 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 configured to promote even air flow inside the air delivery unit and increases the velocity of the outlet air contributing to air enhancement, as it draws surrounding air toward the air delivery unit, thereby increasing overall air delivery; 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°-20° 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 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.

9. 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.

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

11. The bladeless fan as claimed in claim 1, Due to curved profile with variable cross section through length, increasing the overall airflow rate, also focused air flow around center of air delivery unit.