There are four types of electric heating plates, such as thin shell type, cast plate type, tubular element type and tubular element casting type.
1. The thin-shell type electric heating plate is formed by embedding a spiral electric heating wire in a shell formed by stamping of a metal thin plate, and the spiral electric heating wire and the metal outer casing are filled with a heat conductive and insulating filler. The metal thin-shell structure is simple and inexpensive, but the plate surface is easily deformed, and the thermal efficiency is degraded after long-term use, so that a low-power electric heating plate of 800 W or less is generally produced.
2. The structure of the cast plate type heating plate is the same as that of the thin shell type heating plate, except that the plate surface is a metal casting part, so the strength is large and the surface of the plate is not easily deformed. At present, most of the domestic structures are adopted. The tubular element type electric heating plate is a hot plate formed by bending a metal tubular electric heating element into a planar spiral involute. The metal tubular electric heating element has a semicircular cross section, and the plate surface is flat, such a cross section enables the electric heating plate and cooking. There is a large heat transfer surface between the bottom of the pot to improve thermal efficiency. Tubular component cast plate heating plate
3. The tubular element cast plate type heating plate is formed by bending a general metal tubular electric heating element into a ring shape of 1 to 5 turns, and then casting a complete electric heating plate with silicon aluminum alloy or silicon copper alloy. It has a larger effective heat transfer surface than the tubular element type hot plate. The structure has large mechanical strength, long service life and high thermal efficiency, and is particularly suitable for use in a vibrating environment such as a ship or a vehicle. At present, most of the rice cookers produced domestically and externally adopt this structure.