Views: 0 Author: Site Editor Publish Time: 2026-06-02 Origin: Site
Landfill gas (or biogas), after initial collection, is typically in a "wet-heat saturated" state and contains hydrogen sulfide (H₂S), siloxanes, and a large amount of fine particulate matter. This places extremely high demands on heat exchangers:
Fouling and Blockage: Tar-like substances, particulate matter, and microbial metabolic products in the gas readily adhere to the pipe walls. Experiments show that when the heat exchanger wall temperature is below the dew point temperature (usually in the 80℃-110℃ range), fly ash easily adheres to the wet walls, forming deposits that are difficult to remove.
Low-Temperature Corrosion: Combustion of sulfur-containing gases or contact with water produces acidic condensate. Studies show that corrosion begins to appear when the heat exchanger inlet oil temperature (or pipe wall temperature) is below 80℃; when it drops to 62℃-70℃, significant corrosion is observed, and heat exchange performance deteriorates sharply.
Material Requirements: In highly corrosive environments, the material priority is typically: 316L stainless steel > ND steel > ordinary carbon steel. In actual biogas projects, there are numerous cases where AISI 316L stainless steel is used to resist corrosion.
Enhanced turbulence and self-cleaning: The spiral or corrugated structure creates turbulence inside and outside the pipe, disrupting the boundary layer. This continuous fluid scouring effectively slows down the deposition rate of particulate matter on the wall, thus exhibiting a certain "self-cleaning" effect.
Compact design and thermal compensation: The spiral coil structure is compact, resulting in a large heat exchange area per unit volume. Simultaneously, the spiral structure effectively absorbs thermal stress, reducing the risk of pipeline leaks caused by large temperature differences.
