▎ 摘　　要

NOVELTY - Electric heater comprises metal heating pipe (1), which is provided with enamel layer (2) on outer surface. The enamel layer is attached with layer of graphene nano sheet (3). USE - Electric heater. ADVANTAGE - The electric heater is energized, and releases highly oxidizing free radicals ion, and improves water quality inside water heater, and is safe. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for manufacturing electric heater, which involves: (A) mixing enamel glaze ingredients and crushing to obtain powder; (B) heating the powder in furnace at 1100-1250 degrees C for 1-2 hours to obtain molten powder; (C) cooling the molten powder in chilled water, and drying in oven at 90 plus minus 2 degrees C to obtain enamel layer; (D) preparing graphene nanosheet coating by subjecting tin-antimony sol for ultrasonic oscillations to obtain colloid; (E) placing the obtained colloid in water bath for aging; (F) heating metal pipe for carrying out pretreatment; (G) dipping the pre-treated metal pipe with enamel layer, sol and graphene nanosheet coating, and sintering; and (H) heating the sintered product at 300 plus minus 10 degrees C for 10-30 minutes, and calcining at 600 plus minus 20 degrees C for 30 plus minus 2 minutes to obtain the desired product. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the device. Metal heating pipe (1) Stainless steel pipe (1-1) Heat conducting layer (1-3) Enamel layer (2) Graphene nano sheet (3)