Waste heat heater

The invention provides a waste heat heater. The waste heat heater comprises a shell and a heat exchange pipe arranged in the shell, the heat exchange pipe is arranged in the axial direction of the shell, the shell is internally provided with a plurality of supporting plates perpendicular to the heat exchange pipe, and the supporting plate is provided with a plurality of through holes used for passing through the heat exchange pipe, and the supporting plate is provided with a plurality of ventilation holes. More than two rollers are arranged on the periphery of the supporting plate, and a plurality of tracks matched with the rollers are arranged on the inner side wall of the shell. The supporting plate can slide in the shell and disturb the steam, so that the steam distribution is more uniform and the heat transfer is more sufficient. By setting a scraper around the through-hole of the support plate, the support plate can scrape off the wall scale formed by waste steam on the heat exchange pipe in the sliding