Do I Need a Particulate Monitor for My Dust Collector?
Rising cost and stricter EPA regulations have many facilities looking at particulate monitors as a way to reduce cost and meet EPA standards. Any facility with a dust collector knows that eventually filters or cartridges will break and when they do it is costly. Broken filters can be a health hazard to employees, damage blowers, cause the loss of valuable material, and require the facility to pay fines to air pollution authorities. Facilities now realize the cost of a particulate monitor is minuscule in comparison to their cost savings. In some instances particulate monitors can offer return-on-investment in just a few short months!
What is a Particulate Monitor?
Before particulate monitors, opacity monitoring and periodic stack testing were the only methods excepted by the EPA. Opacity monitoring and periodic stack testing were extremely slow and costly methods for testing particulate discharge. A particulate monitor is a device that is mounted in the discharge stack of a dust collector and continuously monitors the amount of particulate discharge. The particulate monitor uses a technology known as Triboelectric or Triboelectricity. When two different materials come in contact, it is likely that one will leave with more electrons than it started with and the other will leave with less, this is called Triboelectric Effect. The interaction between the probe and particles produces a charge transfer within the probe. The charge is then converted to an output signal. Triboelectric dust monitors fall into two categories: AC and DC monitors. Both AC and DC are proven methods for monitoring relative particulate levels.
The EPA plays a large role in determining if a facility must monitor the amount of particulate their dust collectors emit. The Clean Air Act Amendments of 1990 require the U.S. EPA to regulate emissions of toxic air pollutants using technology-based standards. These standards are known as the National Emissions Standards for Hazardous Air Pollutants (NESHAP) and the Maximum Achievable Control Technology (MACT) standards. MACT standards require facilities to meet specific emissions limits that are based on the emissions levels already achieved by the best-performing similar facilities. The purpose of the final NESHAP is to protect the public health which is done by reducing discharges of air toxins from air emission sources.
Sometimes facilities have a difficult time justifying the cost of particulate monitors. Many facilities forget to look at the larger picture. Immediate detection allows facilities to reduce blower wear, avoid costly fines, prolong filter life, reduce labor cost, and reduce employee's exposure to hazardous dust. Facilities can also monitor several dust collectors from a central location allowing personnel to react to bag tears or brakes immediately reducing the environmental impact. By knowing the amount of particulate flowing though a dust collection system, the amount of unnecessary emissions can be reduced. Plant maintenance personnel can plan for bag replacements using the data obtained from the particulate monitoring system. For energy conservation, many facilities re-circulate the air used in the duct collection system.
If we look at the return-on-investment of a particulate monitor, the payback period is typically a few short months.
When selecting a particulate monitor there are a few applications parameters that must be taken into account:
• What type of monitoring is required?
o Some particulate monitors offer a simple 4-20mA output that can be monitored in a control room. Other monitors offer a 4-20mA output and switches which allow the ability to monitor and control a dust collector.
• Will the particulate monitor be located in a hazardous location?
o Based on the classification of the area the monitor will be located, it may need to be intrinsically safe or explosion-proof.
• How will the particulate monitor be mounted?
o Monitors are available with several types of process connections ranging from tri-clamp quick connections to flanges.
• What is the duct size and shape?
o The probe should extend at least halfway across the duct but not touch the other side.
• What is the process temperature range?
o It is important to make sure the process temperature falls within the allowable range of the particulate monitor. Some applications may require a high temperature option.
Our staff of Inside Sales Engineers are also available to help assist in configuring a particulate monitor to best fit your application. Now that you know the tremendous benefits of particulate monitors, we hope to hear from you soon.