Dust Collection & Air Pollution Control

 

Dust control in powder handling operations

Workers in powder handling operations are often poorly protected from dust exposures.

All powder handling operations, such as (big) bag handling, mixing and blending, feeding, dosing, conveying, drying, size reduction, and bulk storage should be evaluated for whether they need dust control.

Why is industrial dust control important?

Bulk solids processing and powder handling operations, such as (big) bag handling, mixing and blending, feeding, dosing, conveying, drying, size reduction, and bulk storage create dangerous dusts that can become airborne, endanger air quality and pose fire and explosion hazards.

These dusts can also cause allergic reactions and respiratory illnesses to operators working on these powder handling lines.

These dry material handling processes require the installation and use of centralized or built-in industrial dust collection systems.

It is essential to protect operators while complying with safety, health, and environmental regulations.

Once the air has been cleaned of impurities with the use of an industrial dust collection system, it can be safely released in the atmosphere.

Industrial dust control amongst the most important safety measures that processing plants need to consider.

In the agriculture, dairy and food processing, mineral processing and pharmaceutical processing industries, combustible particles are expelled during normal processing methods. These particles, if allowed to gather and suspend in the air, can result in a devastating explosion if ignited.

To prevent this, processing facilities normally employ some form of particle filtering and removal that suppresses the threat of an explosion.

These systems are also important for safeguarding worker health against breathing hazards.

Benefits of dust control

The benefits of dust control include, but are not limited to:

• Reducing the risk of fire and dust explosions
• Enhancing safety: Increases visibility at the workplace
• Dust suppression systems prevent unpleasant odors
• Reducing site maintenance and cleaning costs
• Reducing equipment wear, therefore saving money
• A healthier workplace helps boost employees' spirit
• Reducing waste of valuable materials

Dust collection system design

Industrial dust collection systems are available for all types of industrial processing lines involving raw ingredients and other dry bulk materials.

A dust collection system is designed to purify air or gas by removing the contaminants or dust particulate from the collected air.

The vast majority of dust collectors have:

• Ducting that is connected to the inlet of a collector,
• A means for filtering the dirty air inside of the unit,
• A blower system for creating an airflow through the ducting system and internal body of the dust collector,
• A cleaning system for the filters and a discharge mechanism for capturing the dust particulate for either waste or reclaim purposes.

All of these dust collector components may vary based on the application, simplifying these elemental key items to dust collection systems.

Types of dust collectors

There are 5 main types of dust collectors:

1. Inertial separators - Inertial separators concentrate or collect particles by changing the direction of motion of the flowing gas, in such a way that the particle trajectories cross over the gas steamlines and the particles are either concentrated into a small part of the gas flow or are separated by impingement onto a surface. By far the most widely used type of inertial separator is the cyclone, in which the gas undergoes some kind of vortex motion so that the gas acceleration is centripetal; the particles, therefore, move centrifugally towards the outside of the cyclone.
2. Fabric filters - Fabric filters (or baghouse filters) are particulate pollution control devices that remove dust from the air. Power generation facilities, flour mills, pharmaceutical, and chemical plants and other industries use baghouses to control the emission of air pollutants. Baghouses typically are 99% (or better) effective at removing dust from the air, even when dust particles are very small.
3. Wet scrubbers - Wet scrubbers are a special device used to remove a variety of pollutants from exhaust gas from furnaces or other devices. These devices use a scrubbing liquid to remove the pollutants.
4. Unit collectors - Unit dust collectors control contamination at its source. They are small and self-contained, consisting of a fan and some form of dust collector. They are suitable for isolated, portable, or frequently moved dust-producing operations.
5. Electrostatic precipitators - Electrostatic precipitators use an electric charge to remove certain impurities—either solid particles or liquid droplets—from air or other gases in smokestacks and other flues.

How to select the right dust collection system?

Selecting and utilizing the right type of dust collection system and filtration technology for specific equipment or process is crucial to control the air pollution generated in the most cost-efficient manner available.

With the many kinds of dust collection systems available, narrowing down the search requires addressing variables such as:

• The application that the dust collection system is required for,
• The characteristics of the dust particles that have to be separated,
• Will the dust collection system be used continuously or infrequently?
• Will the dust collection system be installed in an enclosed space or placed in the open?

Consideration of the above-mentioned factors can narrow down the search for the ideal dust collector for a specific application.

The most suitable dust collection system for specific requirements might be a unit that has:

• The appropriate dimensions
• A cleaning system that is well-equipped for the cleaning
• A dependable ducting system
• A proper filtration system that can effectively handle the size of the particulate