Increase Your Dust Collector's Efficiency

INDUSTRY NEWS

March/April 2024

In February, the Environmental Protection Agency (E.P.A) finalized a stronger air quality standard that tightens limits on one of the most common and deadliest forms of air pollution - fine industrial particles.

Fine particulate matter, commonly known as soot, can come from factories, car emissions, power plants and other industrial facilities. For even the healthiest among us, particulate matter (PM) pollution can cause breathing trouble, asthma attacks, heart attacks, strokes, lung cancer and even premature death. The millions of individuals across the U.S. with chronic illness or the nearly 25 million Americans with asthma are at an even greater risk.

By 2032, the EPA maintains that annually, the stronger air quality standard for fine particulate matter will help avoid up to 4,500 premature deaths, 290,000 lost workdays, and yield up to $46 billion in net health benefits. For every $1 spent to comply with this action, there could be as much as $77 in human health benefits.

The new rule lowers the annual standard for fine particulate matter to nine micrograms per cubic meter of air, from the current standard of 12 micrograms. Using air sampling over the next two years, the E.P.A. will identify areas that do not meet the new standard. States will have 18 months to develop compliance plans for those areas. Any that still exceed the new standard by 2032 could face penalties.

Dust Collection Efficiency

Create a Cleaner, Safer Work Environment

Dust poses serious consequences that impact workplace safety, air permit compliance, and even corporate finances.

Employee Health
Regulatory Fines
Air Permit Violations
Equipment Damage
Reduced Product Quality
Unplanned Shutdowns
Negative Press
Costs to Address These Issues

Fortunately, there are several ways you can help improve your dust collection system and greatly reduce if not eliminate these consequences.

System Design
Filter Bag Media/Material Selection
Proper Bag Installation
Regular Maintenance
System components

System Design

Obviously, a good system design provides a strong foundation. SLY adheres to several factors that play a critical role in an engineered dust collection system.

Air to cloth ratio — The air to cloth ratio ensures adequate surface area to capture dust based on the flow rate. The type of material being captured, the inlet dust concentration and the required removal efficiency are all used to determine the proper air to cloth ratio.

Interstitial velocity — Inside a dust collector, it is the upward velocity of the air through the open area between the filter bags. Too fast when the controller pulses and the material will tend to stay in suspension and be recaptured on the bag rather than into the hopper.

Material characteristics

Particle size
Moisture level
Abrasiveness

Regulatory Requirements — SLY designs all systems to help facilities comply with federal and local regulatory bodies. Access platforms and ladders are designed to OSHA specifications.

Environment — Baghouse designs should consider environmental factors related to its location, such as wind loading, snow loads, live loads and seismic loading (earthquake).

Media Selection for Bag House Filters

When selecting your bag media, consider the following:

The characteristics of the particulate that requires capture, such as particle size distribution, abrasiveness, moisture, followability, etc.
Required emission rates for your locality
Gas characteristics (i.e. gas composition, operating temperature, humidity, etc)

Properly Installed Filter Bags

Improper installation of filter bags can rip or tear the bags, and decrease or void their dust collecting capacity. Install the filter bags with the proper sealing method to avoid dust particles bypassing the bags.

Filter bags are either top-loaded or bottom-loaded. Properly tighten clamps on bottom-loaded bags to eliminate any gaps. Top-loaded bags have a band at the base which must seal against the tube sheet.

Watch for signs that indicate improper bag installation:

Loose seal against the tube sheet (the point where the bags connect to the system)
Bags that turn easily
Loose clamps (on bottom-loaded bags)

Scheduled Maintenance

A baghouse offers years of reliable service but the bags themselves do eventually need replacement. Cleaning the bags to the right degree and on a regular cycle helps minimize the amount of cleaning cycles and results in lower compressed air usage, reduced filter wear and lower operating differential pressures to reduce energy consumption.

The bag cleaning cycle is commonly based on a timed cycle or pressure drop. When the pressure drop reaches a preset pressure, it automatically initiates a pulse or cleaning cycle. This pressure drop offers a key indicator for bag replacement. A change in pressure drop outside of the norm indicates the bags are starting to “blind” or become so loaded with dust they can no longer be cleaned effectively and must be replaced. Higher than optimal system differential pressure results in higher operating costs.

Cleaning the bags to the right degree means not pulsing or cycling too frequently. Each bag should retain a certain amount of caked up dust, because this helps with the filtration. An experienced baghouse operator knows a bit of caked dust on the bags aids with system efficiency.

As a general rule, a bag inspection is recommended once per year. If the dust or particles collected are more abrasive, this could translate into a more frequent bag inspection. Bag changes are easy with a SLY LLC “no tools required” design.

Call us with questions about improving the efficiency of your dust collection system.

For more information, contact your TEC representative.