The enamel heat exchange part belongs to the new application of enamel products in the petroleum, chemical and thermal power generation industries. It has the advantages of corrosion resistance, acid resistance, temperature resistance and sudden change performance, etc. Thermal parts are mainly used for air preheating containers.

1. Specification of steel for enamel

The tubular enamel heat exchange parts are made of high-quality carbon structural steel pipes with a diameter of 40mm and 50mm, and the wall thickness is greater than 2mm.

2. Preprocessing

Pipe fittings with single-sided enamel can be pickled or sandblasted, and double-sided enamels should be pickled to remove scale and rust.

3. Enamel Coating

The outer wall of small-diameter pipe fittings is coated with flow coating. Hold the pipe fittings horizontally on a piece of equipment, and let the pipe fittings rotate at a low and uniform speed. Above the pipe fittings, there is a flow coating device that moves horizontally and at a uniform speed. The glaze slurry is poured on the rotating pipe fittings, and then the pipe fittings are removed vertically to control excess. glaze paste. The inner wall is coated with enamel to fix the pipe vertically. After filling the inside of the pipe with the glaze slurry, let the glaze in the pipe flow out and control the excess glaze.

The inner and outer walls of small-diameter pipe fittings are coated with dipping enamel, and large-diameter pipe fittings can be sprayed or dipped.

4. Firing

After enameling, use hot air convection drying, and the drying temperature is preferably 80~100℃. The key drying of the inner and inner walls is to use hot air nozzles, which can directly blow hot air into the pipe fittings, but the wind speed should be less than 2m/s. The firing temperature is controlled at 820~880℃.