Project Background

To reduce sulfur dioxide emissions and meet increasingly stringent environmental regulations, a large aluminum smelter in Russia adopted a wet limestone/lime flue gas desulfurization (FGD) system.

Unlike conventional industrial ventilation projects, an FGD system involves multiple process stages including raw lime storage, hydrated lime storage, pneumatic conveying, lime hydration, ash handling and process ventilation. Each stage has different airflow characteristics and operating requirements.

SIMO BLOWER was selected to supply customized centrifugal fans for multiple process units throughout the project, providing reliable air movement solutions for the complete lime preparation and desulfurization system.

Project Information

Why Multiple Fans Are Required in One FGD System

Many people assume that an FGD project only requires an Induced Draft (ID) Fan.

In reality, different process stages require completely different airflow functions.

Rather than supplying one standard fan, SIMO engineered customized centrifugal fan solutions for each operating condition.

Process 1

Raw Lime Storage Dust Collection

Equipment

Raw Lime Silo Dust Collection Fan

Function

During lime storage and filling, fine dust is generated continuously.

The centrifugal fan works together with the bag filter to maintain negative pressure inside the silo, preventing dust leakage and improving workplace cleanliness.

Key Objective

Efficient dust collection with stable negative pressure.

Process 2

Hydrated Lime Storage

Hydrated lime handling also requires continuous dust extraction to keep the storage system clean and environmentally compliant.

The fan is designed for continuous operation with reliable airflow and low maintenance.

Process 3

Ash Handling System

The ash handling section includes two different airflow applications.

Ash Silo Top Dust Collection Fan

Maintains negative pressure during ash storage.

Bottom Discharge Exhaust Fan

Captures fugitive dust generated during material unloading.

Although both are centrifugal fans, they perform completely different functions.

Process 4

Air Slide Conveying

Unlike dust collection, this section requires positive airflow.

Ambient air is supplied by the centrifugal fan, heated by an air heater and then delivered into the air slide.

The heated air fluidizes the powder, allowing smooth and continuous pneumatic conveying.

Process Flow

Air

↓

Centrifugal Fan

↓

Air Heater

↓

Air Slide

↓

Powder Conveying

Process 5

Lime Hydrator

The lime hydrator also requires heated process air.

The centrifugal fan continuously delivers heated air into the hydrator to support stable lime hydration and ensure reliable operation.

Process Flow

Air

↓

Centrifugal Fan

↓

Air Heater

↓

Hydrator

Process 6

Main Process Ventilation Fans

As project construction progressed, SIMO supplied additional large-capacity centrifugal process fans for key operating units.

Typical Design Data

Airflow

381,324 m³/h

Pressure

6500 Pa

Temperature

95°C

Main Features

✔ Wear-resistant impeller

✔ Wind-cooled bearing housing

✔ Triple labyrinth sealing

✔ Q690 high-strength shaft

✔ 42CrMo main shaft

✔ Drainage structure

✔ Large inspection doors

Designed for continuous heavy-duty industrial operation.

Manufacturing & Quality Control

Every fan supplied for this project completed:

✔ CFD-assisted aerodynamic optimization

✔ Precision welding

✔ ISO 21940 G2.5 Dynamic Balancing

✔ Performance testing

✔ Vibration inspection

✔ Dimensional inspection

✔ Final factory acceptance testing

Every fan is manufactured according to the actual operating conditions instead of using a standard configuration.

Project Results

Customized centrifugal fan solutions were provided for multiple FGD process units.

Stable operation under continuous industrial service.

Optimized airflow for dust collection, conveying and process ventilation.

Reduced maintenance requirements.

Designed for long-term reliability.

Conclusion

An FGD system is far more than a single induced draft fan.

Every process—from lime storage and dust collection to pneumatic conveying, lime hydration and process ventilation—requires a different airflow solution.

At SIMO BLOWER, we believe that understanding the process is the foundation of reliable fan selection.

Instead of supplying standard products, we design centrifugal fan solutions based on actual operating conditions to help customers achieve safer, cleaner and more efficient industrial production.