Classification by product structure

The products of electric heating treasure are electric heating cake, electric hot water bag and electric heating hand-warming treasure.

Solid electrothermal cake

It is filled with insulating cotton (such as ceramic cotton, etc.) and heated by electric heating wire, which transfers heat to asbestos or glass fiber for heat preservation. The working principle is that the heat energy is gradually released by using a double-temperature-controlled electrothermal energy storage structure. An automatic superheat protection device and an automatic thermal insulation indicator are built in. A small electric furnace controlled by a PTC thermistor switch. PTC is a thermistor with a positive temperature coefficient. When the current passes, it will heat itself (the heat of the furnace will also be transmitted to it). When the temperature reaches a certain value, its resistance will increase sharply, which can be regarded as disconnection. At this time, the electric heating treasure reduces the consumption of electricity, and then relies on insulation cotton to heat the circuit slowly. This kind of electric heating treasure has a long holding time, but its disadvantage is that it can not completely cut off the circuit. In order to prevent it from being separated when heating, and the temperature after heating is high, cloth bags must be put on when using to avoid scalding. At present, this control method is seldom used on the market.

Electric hot water bag

Soft liquid electric heat treasure uses new energy storage and heating agent, heating rapidly. One-time water injection, permanent use, unique explosion-proof, non-iron and temperature control protection device; long service life; long-lasting insulation and other advantages. Because users can use it directly without water injection, the trouble and insecurity caused by frequent water exchange of traditional hot water bags are avoided. According to the heating principle of the electric hot water bag, this kind of electric heating treasure can be divided into two types: the electrode type and the electric heating element type. Among them, the risk of leakage is also great because the two electrodes (or screw) are directly exposed in the water.

Battery Warm Hand Treasure

This product uses built-in lithium batteries or 5 batteries for power supply, using the principle of resistance to generate heat to warm hands. At present, the product was first introduced by Sanyo in 2010, and then imitated by many manufacturers in winter of 2011, but the quality of the product has not been surpassed. Compared with the first two types of products, the heating is not constrained by the power supply. It can rapidly raise the temperature to less than 40 C. For the built-in lithium battery, it can be fully charged for use when needed. For the use of No. 5 battery, it is more convenient to replace at any time and anywhere, especially suitable for outgoing. Advantages of the product: heating at any time and anywhere, free from the sound of the city movies, light volume, constant temperature heating within the safety temperature required for normal human heating at 40 C, is very safe; Disadvantage: due to the compact size of the product, the battery capacity is not ideal, heat conduction time is not long enough, usually up to 1 hour (higher than this value, all are). False propaganda), because of its small size, can not be large-scale heating.

Classification according to heating principle

The electric heating treasure is divided into two types: the electrode type and the electric heating wire type. Among them, there are positive and negative electrodes in the electric heating treasure, which are directly in contact with the liquid (electrolyte solution) in the bag. When the electrodes are electrified, the solution will be heated with electricity. The heating time is shorter (about 2-8 minutes), but the liquid expands faster and explodes easily. There is an insulator coil in the electric heater. The volume of the coil is larger than that of the electrode heater.