Dust Accumulation in Flue Gas? — Square H Fins & Wheel L Fins Improve Self-Cleaning

In many industrial boilers and waste heat recovery systems, dust accumulation and ash deposition in flue gas passages are long-standing problems that cause frequent shutdowns, cleaning difficulties, and reduced thermal efficiency. Conventional spiral fin tubes have narrow gaps and curved surfaces, where soot particles easily deposit and harden under high temperature. Over time, these deposits form an insulating layer, blocking gas flow and significantly lowering heat transfer performance.

To address these issues, Zhongyue Metallurgy developed advanced Square H Fin Tubes and Wheel-Type L Fin Tubesfeaturing superior self-cleaning and anti-fouling properties. The Square H Fin Tube adopts a rectangular fin design welded symmetrically on both sides of the base tube. This structure creates a straight-line airflow channel, minimizing dead zones where dust can accumulate. The parallel fin arrangement improves gas flow distribution, enabling higher heat transfer coefficients and better soot removal during operation.

The Wheel L Fin Tube, on the other hand, uses a circular segmented fin design resembling a turbine wheel. Each fin section allows partial gas flow through its open channels, producing turbulent airflow that continuously sweeps the fin surfaces. This natural turbulence effect prevents ash from settling and assists in automatic cleaning while the system is running. The wheel structure also enhances the heat dissipation area without adding significant weight or pressure drop.

Both fin types can be manufactured from carbon steel, stainless steel, or alloy steel materials such as A179, A210, 20G, and TP304, depending on the working temperature and medium composition. Fin thickness ranges from 1.5–3.5 mm, with pitch spacing as low as 10 mm, ensuring structural robustness and high-efficiency heat transfer. For corrosion protection, the outer surface of each tube is coated with red oxide zinc phosphate primer, while the inner side contains VCI (volatile corrosion inhibitor) to prevent internal rust formation during storage and operation.

Field data show that boilers equipped with Zhongyue’s Square H Fin and Wheel L Fin Tubes maintain stable thermal performance for over 12 months, with cleaning intervals extended by up to 30–40% compared to conventional spiral fins. These innovative fin geometries have proven especially effective in coal-fired boilers, waste heat recovery units, and biomass heating systems, where high-dust conditions typically challenge efficiency.

By combining optimized airflow design, precision welding, and anti-corrosion coating, Zhongyue’s finned tubes deliver long-term reliability and reduced maintenance costs—helping industries achieve cleaner, more efficient, and low-carbon thermal operation.