Centrifugal Blower for Combustion Air Supply — Manufacturer & Supplier
Vayuvents Pvt. Ltd. manufactures and supplies forced-draft (FD) and induced-draft (ID) centrifugal blowers for combustion air supply to boilers, furnaces, kilns, and industrial burner systems across power generation, cement, steel, chemical, and process industries.
Combustion requires a precisely controlled supply of air to the burner — sufficient for complete combustion of the fuel while minimising excess air that reduces thermal efficiency. The forced-draft centrifugal blower delivers the required volume of combustion air at the pressure needed to overcome burner resistance and furnace backpressure.
Vayuvents has supplied FD blowers for coal-fired and oil-fired boilers, gas furnaces, rotary kilns, and industrial burner systems — from small 500 kg/hr steam boilers to large 50 tonne/hr industrial boilers requiring multiple large FD fans.
Our combustion air blowers are designed in accordance with IBR (Indian Boiler Regulations) and IS 4894 standards, and we provide all documentation required for boiler registration with the Chief Inspector of Boilers.
How It Works in This Application
Fuel Supply to Burner
Fuel (coal, oil, gas, or biomass) is fed to the burner at a controlled rate matched to the combustion air supply.
Forced Air Supply
The centrifugal FD blower delivers pressurised combustion air to the burner windbox or air registers surrounding the fuel feed point.
Combustion in Furnace
Fuel and air mix in the combustion zone, initiating combustion that releases heat transferred to the water or process fluid through the heat transfer surfaces.
Flue Gas Exhaust
Combustion products (flue gases) exit through the boiler draft system — either by natural draft or induced by an ID fan — maintaining the correct furnace draught for complete combustion.
Recommended Variants
Forced Draft (FD) Blower
Supplies pressurised combustion air to the burner windbox — the primary combustion air fan for all fuel types.
Most RecommendedInduced Draft (ID) Fan
Extracts combustion flue gases from the furnace, maintaining furnace negative pressure for safe operation.
Secondary Air Blower
Provides additional combustion air to over-fire air ports in large pulverised coal boilers for NOx control.
Preheated Air Blower
Handles combustion air preheated by an air preheater — requires high-temperature bearing and casing construction.
Technical Specifications
| Parameter | Specification |
|---|---|
| Airflow Capacity | 500 to 5,00,000 m3/hr |
| Static Pressure | 200 to 3,000 mmWG |
| Motor Power | 1.5 to 500 kW |
| Impeller Material | MS / SS / Nickel alloy for hot gas |
| Temperature Range | Ambient to 450 degrees Celsius (ID fan) |
| Drive Type | Direct coupled / Belt driven / VFD |
| Standards | IS 4894, IBR, IS 6966 |
Key Features
- Backward-curved non-overloading impeller design prevents motor overload during combustion system fluctuations
- High-temperature casing and bearing options for FD fans handling preheated air and ID fans handling hot flue gas
- VFD-compatible for variable airflow control matching combustion demand to boiler load
- IBR-compliant documentation package for boiler registration with Chief Inspector of Boilers
- Anti-vibration mounts and inlet silencer as standard for low-noise operation in boiler houses
- Access door for impeller inspection without duct disconnection during planned maintenance outages
- Works performance test with pressure-flow curve certificate and motor power measurement
- Split casing design option for easy impeller removal without disturbing ductwork connections
Industries That Use This Application
Power Plants
Forced-draft and induced-draft fans for coal, oil, and gas-fired boilers in thermal power stations
Process Industry Boilers
FD blowers for process steam boilers in chemical, pharmaceutical, and food processing plants
Cement Kilns
High-temperature combustion air supply to rotary kiln burners and clinker coolers
Steel Plants
Blast furnace air supply and coke oven combustion air in steel manufacturing
Chemical Plants
Furnace and reactor combustion air supply in chemical and petrochemical processing
Food & Beverage
Combustion air for steam boilers in dairy, brewery, and food processing operations
Brick & Ceramic Kilns
Combustion air supply to tunnel kilns and intermittent kilns for ceramics and refractory
Textile Mills
Steam boiler FD fans in textile and spinning mills for process steam generation
✓ Supply & Support: Vayuvents manufactures combustion air centrifugal blowers at our Vasai, Mumbai works. We provide IBR-compliant documentation for boiler FD fan applications. We have supplied FD and ID fans for boilers ranging from 500 kg/hr to 50 tonne/hr across India.
FAQs
The FD fan forces fresh air into the burner to supply combustion air — it handles ambient temperature air at positive pressure. The ID fan extracts combustion flue gases from the furnace, maintaining the correct furnace draught — it handles hot flue gas (typically 150 to 350 degrees Celsius) at negative pressure. Large boilers have both FD and ID fans; smaller boilers may rely on natural draught with only an FD fan.
The combustion air flow depends on fuel type, calorific value, excess air percentage, and boiler firing rate. As a general guide, coal combustion requires approximately 10 kg of air per kg of coal at 20 percent excess air, corresponding to approximately 8 m3 of air per kg of coal. Vayuvents provides combustion air calculations and FD blower sizing for your specific fuel and boiler capacity.
Yes. Vayuvents FD blowers are designed in accordance with IS 4894 and we provide all IBR documentation required for boiler registration with the Chief Inspector of Boilers including manufacturer's certificate, material test certificates, and performance test report.
Yes. VFD control of FD blowers is highly recommended for boilers with variable load — it reduces blower speed and power consumption during partial load operation, saving significant energy compared to fixed-speed operation with damper control. VFD-controlled FD fans can save 20 to 40 percent of blower power at 70 percent boiler load.
In most coal-fired boilers with air preheaters, the ID fan handles flue gas at 130 to 180 degrees Celsius. Without an air preheater, flue gas temperature at the ID fan inlet can reach 250 to 350 degrees Celsius. Vayuvents specifies the correct bearing arrangement, shaft sealing, and casing material for the specific flue gas temperature.
Yes. Vayuvents manufactures replacement FD and ID fans to match existing boiler fan specifications. Send us the existing fan nameplate data or datasheet — we will supply a matched or upgraded replacement with current IBR documentation.
Contact Vayuvents at enquiry@vayuvents.com or call +91 90961 88703. Share your boiler capacity (kg/hr), fuel type, required airflow in m3/hr, and static pressure. We will provide an FD blower selection and commercial proposal within 24 hours.
