Product Overview

The Industrial Boiler Centrifugal Fan is an industrial centrifugal fan series designed for boiler ventilation systems.

The G4-73 is primarily used as a Forced Draft Fan (FD Fan) for supplying combustion air to the boiler furnace, while the Y4-73 is primarily used as an Induced Draft Fan (ID Fan) for extracting flue gas and maintaining furnace negative pressure.

The series is suitable for industrial steam boilers, hot water boilers, biomass boilers, waste heat boilers, district heating systems and thermal energy facilities.

EMS provides customized configurations according to airflow, pressure, temperature, dust concentration, gas composition, system resistance and installation requirements.

Main Applications

G4-73 Forced Draft Fan

Boiler Combustion Air Supply
Industrial Boiler Forced Draft
Steam Boiler Air Supply
Biomass Boiler Combustion
Heating Boiler Ventilation
Thermal Energy Systems

Y4-73 Induced Draft Fan

Boiler Flue Gas Exhaust
Industrial Boiler Induced Draft
Furnace Negative Pressure Control
Boiler Dust Collection
Flue Gas Treatment
FGD and DeNOx Systems
Industrial Heating Exhaust

boiler-forced-draft-induced-draft-fan

Typical Technical Parameters

Parameter	Typical Range
Product Type	Boiler Centrifugal FD / ID Fan
Airflow	3,000–300,000 m³/h
Total Pressure	1,000–6,000 Pa
Motor Power	5.5–800 kW
Fan Speed	730–2,900 rpm
Air / Gas Temperature	Up to 250°C typical
Drive Type	Direct / Belt / Coupling
Fan Structure	Centrifugal Fan
Impeller Material	Carbon Steel / Wear-Resistant Steel
Casing Material	Carbon Steel / Customized
Bearing	Industrial Heavy-Duty Bearing
Installation	Horizontal / Customized
Frequency	50 Hz / 60 Hz
Operation	Continuous Duty

Engineering Note: These are typical reference ranges for engineering and website presentation. Actual fan performance should be selected according to the required airflow, pressure, temperature, gas density and total system resistance.

G4-73 vs. Y4-73

Item	G4-73	Y4-73
Full Name	Boiler Forced Draft Fan	Boiler Induced Draft Fan
Function	Supplies combustion air	Extracts flue gas
Installation	Upstream of furnace	Downstream of boiler
Medium	Air	Flue Gas
Dust Level	Usually low	Usually higher
Temperature	Usually lower	Usually higher
Main Purpose	Combustion air supply	Negative pressure & exhaust
Related Equipment	Air Duct / Air Preheater	Dust Collector / FGD / DeNOx

In simple terms:

G4-73 = Boiler FD Fan → Combustion Air Supply

Y4-73 = Boiler ID Fan → Flue Gas Extraction

Both are centrifugal boiler fans, but they operate at different positions and under different operating conditions within the boiler system.

Working Principle

G4-73 Forced Draft Fan

Ambient Air → G4-73 FD Fan → Air Duct → Boiler Furnace → Combustion

The G4-73 supplies pressurized air to the furnace to provide the combustion air required for stable fuel combustion.

Y4-73 Induced Draft Fan

Boiler Furnace → Dust Collector → Flue Gas Treatment → Y4-73 ID Fan → Chimney

The Y4-73 extracts flue gas from the boiler system and overcomes the resistance of dust collectors, flue gas treatment equipment, ductwork and chimneys.

Key Features

Complete Boiler FD & ID Solution

The G4-73 and Y4-73 configurations cover both major boiler ventilation functions: forced draft and induced draft.

Stable Centrifugal Performance

The centrifugal impeller provides stable airflow and pressure for continuous industrial boiler operation.

Environmental System Compatibility

The Y4-73 can be selected according to the pressure losses of dust collectors, FGD, DeNOx and other flue gas treatment equipment.

Wear-Resistant Options

Wear-resistant impellers, liners and reinforced structures are available for dusty ID applications.

High-Temperature Options

High-temperature bearings, cooling arrangements, high-temperature materials and special sealing solutions can be configured according to actual operating conditions.

Multiple Drive Options

Available drive configurations include:

Direct Drive

Belt Drive

Coupling Drive

VFD-Compatible

Variable frequency drive systems can be configured for airflow and pressure adjustment according to boiler load.

Typical Installation Locations

Industrial Boiler Plants
Steam Boiler Plants
Hot Water Boiler Plants
Biomass Boiler Plants
Waste Heat Boiler Systems
District Heating Plants
CHP Plants
Thermal Energy Systems
Boiler Dust Collection Systems
Flue Gas Treatment Plants
Industrial Heating Systems

Selection Requirements

G4-73 FD Fan

Recommended selection data:

Boiler Capacity

Fuel Type

Required Combustion Airflow

Required Pressure

Air Temperature

Air Density

Air Preheater Resistance

Duct Resistance

Motor Voltage / Frequency

Installation Conditions

Y4-73 ID Fan

Recommended selection data:

Boiler Capacity

Fuel Type

Required Flue Gas Flow

Required Pressure

Flue Gas Temperature

Gas Density

Dust Concentration

Flue Gas Composition

Dust Collector Resistance

FGD / DeNOx Resistance

Duct Size and Length

Installation Altitude

Motor Voltage / Frequency

Boiler capacity alone is not sufficient for selecting the fan size. The actual duty point should be determined from the combustion or flue gas volume and the resistance of the complete system.