Hair Dryer Capable of Increasing Air Flow Rate Based on Negative-Pressure Flow Increasing Structure

The present disclosure relates to the technical field of hair dryers, and in particular, to a hair dryer capable of increasing an air flow rate based on a negative-pressure flow increasing structure.

In the field of personal care appliances, a hair dryer, as a commonly used hairdressing tool, has always received attention for its technological development. With the continuous increase of requirements of customers for performance of the hair dryer, the design of the hair dryer is also constantly being innovated.

In the existing hair dryer, in order to increase a flow rate of air entering the hair dryer, a hollow structure is mainly used inside an air duct. When an air flow exits, an air speed increases, and small amount of air is induced to flow towards an air outlet of the hair dryer together with the air flow. However, an existing air flow doubling type hair dryer still has significant shortcomings in practical applications. In addition to air driven by a motor, a small amount of air is induced to flow into the hair dryer, which means that use of a doubling architecture increases a small amount of air. Since heating for the extra air is not considered, a temperature of air blown out by the hair dryer will decrease, and the effect of hair drying will be reduced. Although a small amount of air is added, the overall temperature of the air flow at the air outlet decreases. This is not conductive to improving the efficiency and effect of hair drying.

In order to overcome the drawbacks described above, the present disclosure aims to provide a technical solution capable of solving the above problems.

A hair dryer capable of increasing an air flow rate based on a negative-pressure flow increasing structure includes an air duct part and a handle part docked to the air duct part. The air duct part has an annular cavity, a mixing cavity, and a plurality of stages of annular rings. A main air outlet is provided in a front end of the mixing cavity. A flow-increasing air inlet is provided in a rear end of the mixing cavity. A main air inlet is provided in a lower end of the handle part. An upper end of the handle part is communicated with the annular cavity, so that a longitudinal fluid flow passage from the main air inlet to the annular cavity is formed inside the handle part. A boosting unit is arranged inside the longitudinal fluid flow passage. A heating unit is arranged at a middle section of the mixing cavity.

The plurality of stages of annular rings are arranged between the annular cavity and the mixing cavity. Two adjacent stages of annular rings form a ring nozzle communicated to the annular cavity and the mixing cavity. The ring nozzle faces the main air outlet. A curved bulge inwards extending along the annular cavity is formed on each annular ring located in front of each ring nozzle, so that the ring nozzle forms a curved transition structure from the annular cavity to the mixing cavity.

The main air inlet, the longitudinal fluid flow passage, the boosting unit, the annular cavity, and the ring nozzles form the negative-pressure flow increasing structure to generate, in the mixing cavity, the flow-increasing air flow that enters along the flow-increasing air inlet and then exits through the main air outlet.

Preferably, the annular cavity has a flow guide cavity with a tapered outer side and a transition cavity docked to the flow guide cavity. The outer side of the flow guide cavity forms an angle of 30° to 45° with a horizontal direction. An inner side of the flow guide cavity is composed of the plurality of stages of annular rings. The plurality of stages of annular rings are in a steplike shape from front to back and have inner diameters that gradually decrease. The transition cavity is communicated to an inside of the handle part.

Preferably, the outer side of the flow guide cavity and the last stage of annular ring form a curved transition at a rear end and are set as the flow-increasing air inlet.

Preferably, a spacing between two adjacent stages of annular rings is 0.4 mm to 1 mm.

Preferably, the transition cavity is a horizontally arranged cavity structure; a cross-sectional area Sof the transition cavity is set to be larger than a cross-sectional area Sof the handle part. A transverse length Lof the transition cavity is greater than 1.5 times to 2.5 times an inner diameter Dof the handle part.

Preferably, a cross-sectional area Sof the flow-increasing air inlet is set to be smaller than a cross-sectional area Sof the main air outlet.

Preferably, the heating unit is arranged between the main air outlet and the ring nozzles, and a distance is reserved between the heating unit and the ring nozzles to allow fluids entering the mixing cavity from the ring nozzles and the flow-increasing air outlet to be fully mixed.

Preferably, a connection point is arranged between two adjacent stages of annular rings, and the two adjacent stages of annular rings are connected through the connection point.

Compared with the prior art, the present disclosure has the beneficial effects below:

The plurality of stages of annular rings are formed between the annular cavity and the mixing cavity; the ring nozzle facing the main air outlet is formed between two adjacent stages of annular rings; and the curved bulge inwards extending along the annular cavity is formed on each annular ring located in front of each ring nozzle, so that the ring nozzle forms the curved transition structure from the annular cavity to the mixing cavity. A coanda effect is ingeniously used, and the negative-pressure flow increasing structure is optimized, so that a fluid can flow from the annular cavity to the mixing cavity more efficiently. Then, a high-speed air flow flows out of the ring nozzles to generate a negative pressure. The negative pressure can better induce surrounding air from the flow-increasing air inlet to form a flow-increasing air flow and cause the flow-increasing air flow to move forwards. This improves overall performance of the hair dryer and hair drying efficiency, and further greatly improves a user experience and significantly enhances a doubling effect on wind. Compared with a traditional hair dryer, the hair dryer greatly shortens hair drying time and saves energy for a user.

In addition, the heating unit heats all air that enters the mixing cavity, thereby ensuring that the extra induced air can also reach an appropriate temperature, avoiding a decrease in an air temperature due to an increase in an air volume, ensuring the effect of hair drying, and improving a comfort level of a user during use and hairdressing efficiency, so that the hair dryer achieves breakthrough in performance and practicability.

The heating unit is arranged at the middle section of the mixing cavity, so that fluids that enters along the ring nozzles and a back-pressure air inlet can be blown out from the main air outlet after passing through the heating unit and being heated, thereby enhancing the effect of hair drying.

The additional aspects and advantages of the present disclosure will be partially provided in the following descriptions, some of which will become apparent from the following descriptions, or learned through the practice of the present disclosure.

Reference numerals and names in the drawings are as follows:

The technical solutions in the embodiments of the present disclosure are clearly and completely described below. Apparently, the described embodiments are merely some embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of present disclosure without making creative efforts shall fall within the protection scope of present disclosure.

Referring toto, in this embodiment of the present disclosure, a hair dryer capable of increasing an air flow rate based on a negative-pressure flow increasing structure includes an air duct partand a handle partdocked to the air duct part. The air duct parthas an annular cavityand a mixing cavity. A main air outletis provided in a front end of the mixing cavity. A flow-increasing air inletis provided in a rear end of the mixing cavity. A main air inletis provided in a lower end of the handle part. An upper end of the handle partis communicated with the annular cavity, so that a longitudinal fluid flow passage from the main air inletto the annular cavityis formed inside the handle part. A boosting unitis arranged inside the longitudinal fluid flow passage. A heating unitis arranged at a middle section of the mixing cavity.

A plurality of stages of annular ringsare arranged between the annular cavityand the mixing cavity. Two adjacent stages of annular ringsform a ring nozzlefacing the main air outlet. A curved bulgeinwards extending along the annular cavityis formed on each annular ringlocated in front of each ring nozzle, so that a last stage of ring nozzleforms a curved transition structure from the annular cavityto the mixing cavity.

The main air inlet, the longitudinal fluid flow passage, the boosting unit, the annular cavity, and the ring nozzlesform the negative-pressure flow increasing structure, so as to generate, in the mixing cavity, the flow-increasing air flow that enters along the flow-increasing air inletand then exits through the main air outlet.

After the hair dryer is turned on, the boosting unitoperates in the longitudinal fluid flow passage of the handle part, to drive air to enter the main air inletin the lower end of the handle partand enter the annular cavityalong the longitudinal fluid flow passage. Between the annular cavityand the mixing cavity, a special flow guide structure is formed by the plurality of stages of annular ringsand the curved bulges. The air is ejected at a high speed through the ring nozzlesbetween the adjacent annular rings, thus forming a high-speed transverse air flow. Due to high-speed ejection of the air, a negative-pressure region is formed inside the mixing cavity, thus forming a pressure difference with an external environment of the flow-increasing air inlet. This causes external air to quickly rush into the cavity from the flow-increasing air inletat the rear end of the mixing cavityunder the action of the pressure difference. The induced air flow is mixed with the air flow sprayed from the ring nozzlesin the mixing cavity, and then the mixed air flow is heated by the heating unitlocated at the middle section of the mixing cavityand is finally blown out from the main air outletat the front end of the mixing cavity, thus achieving efficient air blowing.

In the above technical solution, the negative-pressure flow increasing structure is designed by using a Bernoulli principle and a coanda effect. A high-speed motor is used as a power source for the hair dryer, namely the boosting unit. The air flow generated only by the rotation of the high-speed motor is shown in. The air flow induced by the negative-pressure flow increasing structure is shown in. Through the driving of the high-speed motor and the fluid flow passage design of this scheme, the air flow generated by the high-speed motor is mainly blown out against an inner wall. The high-speed air flow is sprayed out through the ring nozzlesand generates the negative pressure inside the mixing cavity. The external air is induced from the flow-increasing air inletthrough the negative pressure to form an air flow. The two air flows are mixed in the mixing cavityand are finally blown out from the main air outlet. The mixed air flow is shown in.

The plurality of stages of annular ringsare formed between the annular cavityand the mixing cavity. The ring nozzlefacing the main air outletis formed between two adjacent stages of annular rings. The curved bulgeinwards extending along the annular cavityis formed on each annular ringlocated in front of each ring nozzle, so that the last stage of ring nozzleforms the curved transition structure from the annular cavityto the mixing cavity. A coanda effect is ingeniously used, and the negative-pressure flow increasing structure is optimized, so that a fluid can flow from the annular cavityto the mixing cavitymore smoothly. Then, the negative pressure generated by the high-speed air flow formed based on the ring nozzles can better drive the surrounding air to enter the flow-increasing air inlet to form the flow-increasing air flow which moves forwards. This improves overall performance of the hair dryer, greatly improves a user experience, and significantly increases a flow rate of air entering the hair dryer. Compared with a traditional hair dryer, the hair dryer can greatly shorten hair drying time and save energy for a user.

In addition, the heating unitheats all air that enters the mixing cavity, thereby ensuring that the extra induced air can also reach an appropriate temperature, avoiding a decrease in an air temperature due to an increase in an air volume, ensuring the effect of hair drying, and improving a comfort level of a user during use and hairdressing efficiency, so that the hair dryer achieves breakthrough in performance and practicability.

Referring toto, the annular cavityhas a flow guide cavitywith a tapered outer side and a transition cavitydocked to the flow guide cavity. The outer side of the flow guide cavityforms an angle of 30° to 45° with a horizontal direction. An inner side of the flow guide cavityis composed of the plurality of stages of annular rings. The plurality of stages of annular ringsare in a steplike shape from front to back and have inner diameters that gradually decrease. The transition cavityis communicated to an inside of the handle part. The air flow can be effectively guided to be accelerated, so that more air can be induced from the flow-increasing air inlet. The outer side and inner side of the flow guide cavityform curved transition at a rear end and are set as the flow-increasing air inlet. This reduces resistance of flowing of the air flow and reduces energy loss. A spacing between two adjacent stages of annular ringsis 0.4 mm to 1 mm, so that this ensures that the air flow is sprayed out at a high speed to generate a negative pressure. The transition cavityis a horizontally arranged cavity structure. In order to avoid an increase in air resistance, a cross-sectional area Sof the transition cavity is set to be larger than a cross-sectional area Sof the handle part, and transverse length Lof the transition cavityis greater than 1.5 times to 2.5 times an inner diameter Dof the handle part. This effectively avoids the increase in the air resistance and ensures that the air smoothly flows into the annular cavity. A cross-sectional area Sof the flow-increasing air inletis set to be smaller than a cross-sectional area Sof the main air outlet, thus avoiding the increase in the resistance, pushing the air flow to quickly move forwards, and achieving efficient air blowing.

During use of the hair dryer, the boosting unitstarts to work, driving the air to enter the handle partfrom the main air inletto form an air flow. Later, the air flow enters the transition cavityfrom the handle part. In order to avoid the increase in the air resistance, the cross-sectional area Sof the transition cavityshould be larger than the cross-sectional area Sof the handle part, but should not be larger than {circle around (2)} times of the cross-sectional area of the handle part, namely, S≥ cos 45°. S. The air flow enters the flow guide cavitythrough the transition cavity, and is blown into the mixing cavityfrom the ring nozzles. The negative-pressure flow increasing structure is a core component of the hair dryer. The negative-pressure flow increasing structure is provided with the flow guide cavity, the plurality of stages of annular rings, and the ring nozzles. The flow guide cavityis a tapered cavity and is obtained according to a continuous equation and a bernoulli equation. The purpose is that after the air flow enters the product, the cross-sectional area gradually decreases, so that the speed of the air may gradually increase, and the pressure may gradually decrease. The continuous equation is ρSV=ρSV, and the bernoulli equation is

According to the principle of aerodynamics, a pressure variable is relatively small, and correspondingly, ρ˜ρ. In this case, β is an air density at a normal temperature and a normal pressure. Therefore,

When the area S decreases, V may increase according to the continuous equation; and the pressure intensity p may decrease according to the bernoulli equation.

Therefore, after being accelerated by the negative-pressure flow increasing structure, the high-speed air flow is formed and is then ejected from the ring nozzles. In this case, the speed is maximum, and the negative pressure can be generated in the mixing cavitythat is connected subsequently. When entering the ring nozzlesfrom the flow guide cavity, the air flow can pass through the curved bulges. According to the coanda effect, when the air flow passes through a curved surface, the air flow can flow against the curved surface due to viscidity of air, thus avoiding flowing separation when the air flow enters the ring nozzlesfrom the flow guide cavityand reducing energy loss.

As mentioned above, after being ejected from the ring nozzles, the high-speed air flow can generate the negative pressure in the mixing cavity, and an atmospheric environment, namely a pressure intensity, in which the flow-increasing air inletis located is 1 atm, and a relative pressure intensity displayed on a pressure gauge is 0 Pa. Therefore, a pressure difference may be formed between the mixing cavityand the flow-increasing air inlet. It can be learned according to the bernoulli equation that,

Finally, the air flow driven by the boosting unitand the air flow induced by the negative-pressure flow increasing structure are mixed together in the mixing cavityand then enter the heating unit. The heating unitheats the air flow to a temperature, and the air flow is blown out from the air outlet to hairs.

Referring toand, the heating unitis arranged between the main air outletand the flow-increasing air inlet, so that the air can be heated immediately after entering the mixing cavity, which reduces loss of heat during transferring and ensures that the temperature of the blown air is stable and efficient. A connection pointare arranged between two adjacent stages of annular rings, and the two adjacent stages of annular ringsare connected through the connection point. This improves overall structural stability of the annular cavityand avoids looseness or deformation of the annular ringscaused by vibration generated by high-speed flowing of the air flow, thus ensuring that the air flow can be stably and smoothly sprayed out from the main air outlet to continuously generate a negative pressure, increasing an air inducing amount, and improving air blowing efficiency. This connection mode further lowers manufacturing and assembling difficulties, facilitates later-stage maintenance and repair, and further improves comprehensive advantages of the hair dryer in performance guarantee and use convenience.

For those skilled in the art, it is apparent that the present disclosure is not limited to the details of the exemplary embodiments mentioned above, and can be implemented in other specific forms without departing from the spirit or basic features of the present disclosure. Therefore, in any perspective, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present disclosure is limited by the accompanying claims rather than the above description. Therefore, all changes within the meaning and scope of the equivalent conditions of the claims within the present disclosure.