Materials for Low Temperature Flue Gas Bundles
Thomas Orth (Author)
Account Manager, Engineering
Technoform Tailored Solutions Holding GmbH
Aaron Smith (Speaker)
Group Lead of Research
HTRI
ABSTRACT
Powerplants, waste incineration and many other industrial processes produce corrosive flue gases. Usually heat recovery in these fluegas streams under 200° is avoided since traditional heat exchanger materials are not compatible with such harsh condition. Going below acid dew point at about 160° will cause massive corrosion on metallic surfaces due to sulfuric-, hydrochloric- and hydrofluoric acid condensates. Tubes with protective coating (such as PFA or enamel) often suffer corrosion due to delamination or diffusion, even glass has issue with HF. Technoform is a manufacturer of composite polymer tubes. The tubes are made of polyphenylene sulphide polymer (thermoplastic polymer) blended with 70% graphite (thermally conductive filler). This material has high corrosion resistance and is suitable for temperature up to 250 °. This allows for full condensation to extract more heat for enhanced efficiency. Thermal conductivity is 4-5 times higher than glass and above coated steel. The higher thermal conductivity allows for smaller less costly heat exchangers and operating costs. This is illustrated through an HTRI Xist® case study.