Guest Authors: Tim White & George Armbruster
The importance of continuous dust monitoring across all industries is often overlooked. Neglecting to make plant cleanliness a priority and actively avoiding the implementation of dust monitoring programs can lead to disaster. Every year, there are a number of reported explosions at processing and manufacturing plants which have led to the injury of employees and loss in company assets. Modern advancements in dust monitoring technology continues to make strategies safer and more efficient.
Electrostatic Induction Technology
The Finnish company Sintrol makes a line of dust monitoring equipment that utilizes Inductive Electrification technology to reliably and continuously measure dust concentration at a competitive price. The basic principle of Inductive Electrification is that particles in motion will interact with an isolated probe mounted in a duct or stack. When these charged particles pass nearby or hit the probe, an electric current is induced. This electric current can then be processed through an analog to digital conversion in the devices onboard processor, and then put through a series of noise-filtering algorithms. This will translate the signal into an incredibly accurate dust measurement output.
Previous Continuous Dust Monitoring Approaches
Before Inductive Electrification was theorized, classic Triboelectric was the technology of it’s day. Triboelectric measurements are generated by particles making direct contact with the sensor, transferring the charge. This method often leads to high maintenance costs due to the requirement of customers having to remove the accumulation of dust on the probe and recalibrate frequently to ensure accurate measurements.
The same issue could be found in Light-Scattering Devices. Lenses in the optical system of the devices accumulate dust and drift away from calibration to provide inaccurate dust concentration values. Many Light-Scattering Devices avoid this by simply recalibrating; however, accumulated dust will almost always result in the unit needing repair or cleaning. This is known as sensor drift; however, devices using Inductive Electrification do not drift, and should need no calibration.
Benefits of Inductive Electrification
When compared to these other measurement technologies, Inductive Electrification Technology is found to be far more sensitive and minimizes the influence of sensor contamination, temperature drift and particulate velocity change. By using Inductive Electrification technology, it is even possible to reach dust concentration measurement thresholds as low as 0.01 mg/m3 and as high as 6 g/m3. Even the newest Light-Scattering Devices can only go to around 250 mg/m3 before the devices reach their measurement limits.
Another important benefit of combustible dust monitoring systems is the ability to monitor areas difficult for employees to reach. Installing devices above and beneath grain silos or in and around dangerous areas can make for a safer environment from both a monitoring standpoint and by keeping employees out of danger. Electrostatic Induction devices can be used in many explosive-rates areas as the sensor is a single solid piece of metal. The rest of the device is fully enclosed in an EX-rated housing.
Sintrol Dumo EXG A
The Sintrol Dumo EXG A is an explosive-rated continuous dust monitoring device using inductive electrification that is certified in accordance to UL / CSA standards for use in Class II, Division I, Subgroups E, F& G combustible dust environments. The Dumo EXG A is a special breed of dust monitor meant for permanent installation. The Dumo EXG A pulls the surrounding air in and almost immediately outputs a dust concentration measurement to various hardware communication interfaces, 4-20mA Modbus, RS-485, and 900MHz RF. With a network of these devices installed, a company can monitor the fugitive combustible dust in their entire plant with one operator in a control room. Dust trends and dust spikes can be seen in a matter of seconds which allows operations personnel to quickly respond and inspect areas inside a plant generating unacceptable levels of fugitive dust.
Mr. White (Lead Project Engineer) and Mr. Armbruster (V.P. Sales) are experts in combustible dust monitoring and instrumentation at VarSci, LLC. Visit the VarSci, LLC website to find more information on the Sintrol Dumo, Sintrol Snifter, and other dust monitoring solutions.
