The hair dryer is mainly used for drying and shaping hair, but it can also be used for local drying, heating and physiotherapy in laboratories, physiotherapy rooms, industrial production, art and other aspects. According to the type of motor it uses, it can be divided into AC series, AC shield pole and DC permanent magnet. The advantages of series excited hair dryer are large starting torque, high speed, suitable for manufacturing high-power hair dryer; The disadvantage is that the noise is large, and the commutator has certain interference with the telecommunications equipment. The advantages of the cover pole hair dryer are low noise, long life, and no interference to telecommunications equipment; The disadvantages are low speed, poor starting performance and large weight. The advantages of permanent magnet hair dryer are light weight, high speed, simple manufacturing process, low cost, and cheap. The size of the hairdryer is mainly divided by electrical power, and the commonly used specifications are 250 watts, 350 watts, 450 watts, 550 watts, 850 watts, 1000 watts, 1200 watts and so on. Although there are great differences in the type, style and size of the hair dryer, their internal structure is roughly the same, mainly composed of three parts: the motor and its driving wind blades, heating components and electrical control switches. The motor, the blades and the housing structure are combined to form a miniature hair dryer.

With the reform and gradual improvement of the performance of the hair dryer, a set of constant temperature automatic electronic control elements are connected in series on the heating element of the hair dryer at home and abroad, which can automatically switch on the circuit under the normal operation of the air duct, and automatically cut off the circuit in special circumstances (such as overheating of the electric heating element). In the selection of wind duct shell materials, the past selection of metal (such as copper or cold rolled iron sheet) materials, to the selection of thermoplastic engineering materials (mainly polycarbonate, modified polystyrene, modified polypropylene, etc.) made. Working principle The blower directly relies on the motor to drive the rotor to drive the wind blade to rotate. When the wind blade rotates, air is drawn from the intake, and the resulting centrifugal air is blown out by the front mouth of the wind duct. When the air passes through, if the heating wire installed on the heating bracket in the air nozzle has been energized and heated, the hot air is blown out; If the selection switch does not make the heating wire energized and heated, it blows out cold air. Hair dryer is to achieve the purpose of drying and shaping. The selection switch on the handle of the hair dryer is generally divided into three gears, that is, the close gear, the cold wind gear, and the hot air gear, and the color is white, blue, and red signs. Some hairdryers are also equipped with motor speed control switches on the handle to choose the size of the air volume and the temperature of the hot air. The back or side of the shell of all kinds of hair dryers are provided with a rotating circular air conditioner, which can adjust the cross section size of the air intake to adjust the conveying wind speed and the temperature of the hot air.

According to the way of use, there are hand-held and support hair dryers. Support type hair dryer can be placed on the table or hung on the wall to use, you can blow yourself. According to the air supply mode, there are centrifugal hair dryer and axial flow hair dryer. The centrifugal type relies on the motor to drive the wind blade to rotate, so that the air entering the hair dryer obtains the inertial centrifugal force and constantly exhausts the air. Its disadvantage is that the discharged wind does not all flow through the motor, the motor temperature is higher; The advantage is lower noise. The axial flow motor drives the wind blade to rotate, pushes the air into the hair dryer to flow axially, and continuously exhausts the air. Its advantage is that all the discharged wind flows through the motor, the motor cooling conditions are good, and the insulation is not easy to age; Its disadvantage is that it is noisy. According to the material used in the shell, there are metal type hair dryers and plastic type hair dryers. Metal type hair dryers are durable and can withstand higher temperatures. The plastic type hair dryer is light in weight and has good insulation performance, but it is easy to age and poor in high temperature resistance. Although there are many types of hair dryers, the structure is much the same, and they are composed of the shell, handle, motor, wind blade, electric heating element, windshield, switch, power cord and so on.

The role of each part of the hair dryer is: 1, the shell. It has a protective effect on the internal parts and is also an external decorative part. 2. Motor and blades. The motor is mounted in the housing, and the wind vane is mounted on the shaft end of the motor. When the motor rotates, air is drawn in by the inlet and air is blown out by the outlet. 3. Electric heating element. The electric heating element of the hair dryer is wound with an electric wire and installed at the outlet of the hair dryer. The air discharged from the motor is heated by the electric wire at the outlet and is sent out as hot air. Some hair dryers install a thermostat near the electric heating element, and cut off the circuit when the temperature exceeds the predetermined temperature, which plays a protective role. 4. Windshield. Some hairdryers have circular windshields at the air inlet to adjust the air inlet volume. A hair dryer without a circular windscreen can also be used to adjust the air intake with a part of the air intake. When the inlet air volume is small, the blowing out wind is hotter, and when the inlet air volume is large, the blowing out wind is not too hot. It should be noted that the tuyere should not be blocked too much, otherwise it will damage the motor or burn out the electric heating element due to high temperature. 5. Switch. Hair dryer switch generally has "hot air", "cold air", "support" three positions, commonly used white means "stop", red means "hot air", blue means "cold wind". The electric heating element of some hair dryers is composed of two or three electric heating wires to adjust the temperature, which is controlled by a selection switch.