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MIT, LIT, MIE - Characterizing for Dust Hazard Analysis DHA

Posted by Sara Peters on Sep 11, 2017 5:20:00 AM
MIT, LIT, MIE Characterizing for Dust Hazard Analysis DHA Fauske & Associates, LLC

Video transcript

Hello again, I'm Mark and this is Deb. We're with Fauske & Associates. We've been following our dust sample through our lab today we're at the ignition sensitivity area, so let's go test out our sample and see what happens in here. Hold on a second Mark, before we go in there make sure that we're wearing safety glasses anytime we're in the lab. Thanks Deb. Let's do this. This is the MIE three chamber. This tells us what the minimum ignition energy or MIE is of your material. The goal of this test is to find out what's the minimal amount of energy needed for my sample to react within a dust cloud. The test can be run one of two different ways, with or without inductance. With inductance we'll test for electronic or electrical hazards that are present in your process. While without inductance, we'll test for electrostatic as your process. Between the two methods with inductance will yield the more conservative results.

There are some materials that react to even the smallest electrostatic charge. The goal of this test is to tell us what is that minimum ignition energy to make my sample react. It's measured in a unit called millijoule. Some samples even react to as small as one millijoule. If I walk across the room and get a shock from the doorknob, that's about 30 millijoules of energy. We conduct multiple trials per sample to pinpoint the minimum amount of energy needed to create an ignition. The results of the testing are stated in the number of millijoules it takes to ignite the sample. This is our BAM oven, which tells us what the minimum ignition temperature or MIT is of your material. This is perfect for the areas of your facility where you may have hot atmospheres like ovens or machinery. Let's go take a look at the MIT test in action.

The purpose of this test is to determine the lowest temperature where your sample may explode. Once you have determined this value, you can take steps towards mitigating risks by ensuring temperatures do not exceed unsafe levels. Testing typically starts at 600 degrees Celsius, and multiple trials are conducted at varying temperatures to find our minimum ignition temperature. Another test that's often done along with the MIT is the layer ignition temperature or LIT, which is shown behind me right here. The purpose of this test is to determine the minimum temperature at which your material is likely to ignite. This is designed to simulate dust accumulations on hot surfaces. Each trial can go up to two hours or until the sample layer melts or ignites. Testing is discontinued if there is no reaction at 450 degrees Celsius. The tests performed here provide valuable data to characterize your material and process. Our onsite service team is available to provide guidance to keep your people and facility safe. Fauske & Associates, world leader in nuclear and chemical processing.

Do you need help assessing whether your dust is combustible? Use our flowchart to help you decide.

Is My Dust Combustible?

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