Bag Leak Detection Blog

Process insights become process control

The use of triboelectric particle velocity monitoring in pneumatic conveying applications is relatively new. In the past, no real viable solutions existed to measure particle velocity in dilute phase pneumatic conveying systems. Pitot tubes can be used to measure air velocity in such systems but encounter problems when introduced into dust-laden air thereby limiting them to only for occasional diagnostic uses. In contrast, triboelectric systems for particle velocity monitoring have no issue working in applications with heavy dust loads. Additionally, because they track the velocity of moving particles themselves rather than measuring airspeed they present a more accurate picture of conveying conditions within the ductwork. 

But what kinds of pneumatic conveying problems can triboelectric particle velocity monitors remedy? Let’s consider two very common problems that come up with pneumatic conveying systems. 

No matter what the application accumulations of dust within a duct work system can present a host of problems to industrial facilities. Dust buildup in baghouse ducts can impact operations of the dust collection system, thereby directly affecting production. Malfunctioning dust collection also generates respiratory safety hazards as well as creates a substantial risk for combustible dust fires and explosions. Additionally, poorly performing systems directly impact a plant’s emissions limits, which can lead to heavy fines, sanctions or even forced shutdowns by regulators. 

How can operators and technicians prevent this issue and avoid these serious consequences in their facilities? 

The Mercury Emissions Challenge

The EPA’s Mercury emissions standards have proved one the biggest environmental regulatory developments in the US in the last 30+ years. Industry was vocal in their hesitation about the formulation of these standards for decades. After the rules were codified in 2005, the MATS or Mercury and Air Toxics Standards faced vigorous opposition, with over 20 states suing to have them vacated with the case even reaching the United States Supreme Court in early 2015 and 2016. 

One of the topics that generates lots of questions for us in meetings is particle velocity monitoring. Sometimes the reaction is "cool capability, but how's it applicable in our situation?" And if budgets are tight, people assume it will be too expensive and prefer to skip to the next topic. But often the reaction centers around pneumatic conveying where they express a real difficulty understanding what is going on in the pipeline. This is often the case for engineers in industry, and makes troubleshooting an industrial system quite difficult.

Particle velocity monitoring is crucial for proper operation of many process applications and plays a key role in preventing serious problems with dust collection systems that are widely used in nearly every industry. 

For this reason, we thought it would be a good idea to briefly review some compelling reasons why you should seriously consider particle velocity monitoring in your process. 

Air pressure controlled, pneumatic process control systems are used extensively for conveying powder and bulk solids in many industries.  Improperly controlled systems can result in problems for the manufacturing process.  Blockages Flow/No Flow monitoring), material drop out (More Flow/Less Flow monitoring), or  product damage can occur when the product velocity is not directly measured and controlled. For example, during pneumatically transported breakfast cereal operations, the lack of product velocity control can result in significant product damage.  Often the solution is to simply increase the air flow in the system, but the actual effects of this action is unknown inside the pipe or duct.  There is a need for more sophisticated, particulate velocity control technology to help minimize such product damage. 

Triboelectric particulate monitoring systems are recognized as effective tools to measure emissions levels from dust collectors and for broken bag detection in baghouse dust collectors. Since Auburn Systems introduced the first commercial triboelectric broken bag detector almost 40 years ago they've evolved quite a bit. Technical advances have opened up additional application capabilities including interesting Flow/No Flow and More Flow/Less Flow applications. 

The most well-known use of triboelectric detectors is to monitor emissions levels from a dust collector. The primary use of this data is to detect leaks in the baghouse filters at the first sign of leaking so they can be replaced before emissions levels rise to a significant, reportable level.