Application of Centrifugal Fans in Waste-to-Energy Power Generation

In the field of waste-to-energy (WtE) power generation, efficient and stable air handling is critical to ensuring optimal combustion efficiency, reducing pollutant emissions, and maintaining the safe operation of the entire system. Among various ventilation equipment, centrifugal fans stand out as core components, playing irreplaceable roles in multiple key processes—from waste incineration to flue gas purification. Their high pressure, strong adaptability to harsh working conditions, and stable airflow control capabilities make them indispensable for realizing the dual goals of "waste reduction" and "energy recovery" in WtE projects.

1.1 Primary Air Supply

Primary air, drawn and pressurized by centrifugal fans, is blown into the bottom of the incineration grate through air distribution pipes. Its main functions include:

Supporting combustion: Delivering oxygen to the lower layer of the waste pile to ensure full combustion of organic components (e.g., plastics, paper, and food residues), avoiding incomplete combustion that produces harmful substances like dioxins.

Centrifugal fans for primary air are designed with high-pressure impellers (static pressure usually 3,000–8,000 Pa) to overcome the resistance of the grate and waste layer, ensuring uniform air distribution across the entire grate surface.

1.2 Secondary Air Supply

Secondary air, supplied by another set of centrifugal fans, is injected into the upper part of the incineration chamber (above the waste pile). This airflow:

Strengthens turbulence: Mixes unburned flue gas with fresh air, eliminating local oxygen-deficient zones and reducing the formation of carbon monoxide (CO) and dioxins.

Extends residence time: Ensures flue gas stays at high temperatures (over 850°C) for more than 2 seconds, a key requirement for dioxin decomposition.

These fans often feature adjustable blade angles to flexibly adjust air volume based on real-time combustion conditions (e.g., waste composition, temperature fluctuations), maintaining stable incineration parameters.

2. Application in Waste Heat Boilers

After combustion, high-temperature flue gas (around 800–1,000°C) enters a waste heat boiler to transfer heat to water, generating high-pressure steam that drives turbines for power generation. Centrifugal fans contribute to this process in two ways:

2.1 Induced Draft (ID) Fans

Installed at the outlet of the waste heat boiler, ID centrifugal fans create negative pressure in the boiler and incineration chamber. This negative pressure:

Controls flue gas flow: Ensures flue gas flows smoothly through the boiler’s heat exchange tubes, maximizing heat transfer efficiency.

Prevents leakage: Avoids the escape of high-temperature flue gas or toxic substances from the system, protecting the working environment and operator safety.

Given the high temperature (200–400°C) and dust content of flue gas at this stage, ID fans are equipped with heat-resistant casings and wear-resistant impeller coatings (e.g., ceramic or alloy coatings) to extend service life.

Suitable Model: Centrifugal Fan