How Dangerous is Your Process?
IF YOU HANDLE COMBUSTIBLE MATERIAL, AS FOR EXAMPLE COMBUSTIBLE DUST, THE FOLLOWING ASPECTS NEED TO BE TAKEN INTO CONSIDERATION:
- Identify your risk zones.
Examples of risk zones:
- Identify your Ignition Source Generators (ISG)
Examples of ISGs
- What is the oxygen level? The oxygen content needs to be above 11% for combustion to take place.
- Turbulence; if there is less turbulence in the environment, the fire risk is higher.
- Find the Minimum Ignition Temperature (MIT) for the material in your process. (see table)
- Find the Minimum Ignition Energy (MIE) for the material in your process. (see table)
- Is the dust concentrated in a layer or in a cloud? In general, dust in a layer ignites at lower temperatures than in a cloud. (see table)
Minimum Ignition Temperature and Energy Level
Cloud temperature (celsius) | Cloud temperature (fahrenheit) | Layer temperature (celsius) | Layer temperature (fahrenheit) | Min. Cloud Ignition Energy | |
|---|---|---|---|---|---|
Wood | 470 | 878 | 260 | 500 | 0,04 |
Wheat Flour | 440 | 824 | 440 | 824 | 0,06 |
Cellulose | 480 | 896 | 270 | 518 | 0,08 |
Sugar | 370 | 698 | 400 | 608 | 0,03 |
Cocoa | 510 | 950 | 240 | 464 | 0,10 |
Aluminum | 610 | 1130 | 326 | 619 | 0,01 |
Coffee | 720 | 1328 | 270 | 518 | 0,16 |
Source: NFPA (National Fire Protection Association)
- What is the particle size and shape? In general, smaller particles ignite more easily and are more explosive.
- What is the moisture content of the material in your process? In general, a dryer material means a higher risk of fire.
- What are your process-specific parameters, i.e. amount of material, transport speed, duct diameter, chute size, etc.?
- Do you have high-risk machinery that need protection (flame detection and water mist suppression)?
