Please select the most similar patent number from A, B, C and D. Which number is?
Disclosed is an electric hair dryer with dual-purpose length, comprising a housing body (1), an insulating sheath (2) being detachably mounted on the outer wall of a front housing (11) of the housing body (1). When the insulating sheath (2) is not being used, the short body design of the electric hair dryer makes operation more flexible and convenient, reducing the labour intensity for a user. To meet the requirements of users for tasks in which the front housing (11) is customarily gripped, when the insulating sheath (2) is being used, the insulating sheath (2) is located on the outside of the front housing (11) so as not to be directly heated by hot air in the housing body (1) and electrical heating elements. Therefore, even after a long period of use, the insulating sheath (2) will still not cause burns and the user can grip the insulating sheath (2) as needed for drying or shaping tasks without being burned.
A: Provided is a cooling sunshade tool for outdoor use, which is composed of dual flexible pipes, a flexible pipe plug and an insulation cover. The dual flexible pipes comprise an inner pipe (4) and an outer pipe (3). The inner pipe (4) is filled with water (22), and can be bent into arbitrary shapes. The dual flexible pipes are located behind the insulation cover, and are placed into a refrigerator to freeze integrally. Where the insulation cover is of a hard material, it is provided with a plurality of through-holes (11) thereon, and is connected to a box body (14). The box body (14) is provided with a fan (15) therein. The fan (15) sends out a cooled airflow. The sunshade tool has a simple structure and strong practicality.
B: Disclosed are a heater and a non-burning heated electronic cigarette. The heater comprises an inner-layer heating body (100), an outer-layer heating body (101) and a heat insulation sleeve (102), wherein a front end of the outer-layer heating body (101) is a closed end, and a rear end thereof is an open end; two ends of the inner-layer heating body (100) are open ends; a first through hole (103) penetrates through a front end face (110) of the heat insulation sleeve (102), and a second through hole (104) penetrates through a rear end face (112) of the heat insulation sleeve (102); the outer-layer heating body (101) is sleeved in the heat insulation sleeve (102) and forms an outer layer air current heating channel (106) with an inner wall of the heat insulation sleeve (102), and a front end of the outer-layer heating body (101) is in sealing connection with an inner wall of the first through hole (103); the inner-layer heating body (100) is sleeved inside the outer-layer heating body (101) and forms an inner layer air current heating channel (109) with an inner wall of the outer-layer heating body (101), and a rear end of the inner-layer heating body (100) is in sealing connection with an inner wall of the second through hole (104); and several air inlet holes (111) in communication with the outer layer air current heating channel (106) penetrate through the front end face (110) of the heat insulation sleeve (102). The non-burning heated electronic cigarette comprises the heater, and has the advantages of increasing the heating route and heating time of the air, having a small volume, and steadily increasing the heating temperature.
C: A non-combustion electronic cigarette apparatus used under electrical heating, comprising an electrical heating control device (10) and an electrical heating sleeve (11) adjacent to the electrical heating control device (10). The electrical heating sleeve (11) is electrically connected to the electrical heating control device (10); the electrical heating control device (10) comprises a battery, and a bottom region of the electrical heating sleeve (11) is communicated with the outside by means of an air passage. An electrical heating probe (12) mounted at the bottom of the electrical heating sleeve (11) is further comprised. The electrical heating probe (12) is electrically connected to the electrical heating control device (10), and the electrical heating sleeve (11) and the electrical heating probe (12) are insulated and separated.
D: An improved structure for a hair dryer. A body (10) of a hair dryer comprises a front housing (1), a rear housing (2), a conical inner sleeve (3), a central shaft tube (4), a heating unit (5), a power set (6), and an impeller (7). The hair dryer enables linearly proceeding airflows generated by a fan unit to mix with external ambient airflows, so that the hair dryer has strong penetrating force and uniform cold/hot air. Moreover, such penetrating capability speeds up the drying of wet hair; and due to the function of mixing heating airflows and external ambient airflows, swirling airflows blown out from a central air outlet (112) would not have a dry heat temperature, and can be maintained at a desired cold/warm temperature, so that a user feels comfortable during a drying process.
Answer: D