Purpose
The purpose of the Limiting Oxygen Concentration test is to determine the highest oxygen concentration that can be allowed in a process where inerting is used as a measure to prevent dust explosions from occurring.
This test is relevant for facilities handling dust if you would apply inerting as an explosion preventive measure. This measure is generally applied in closed systems such as storage vessels, silos, mills, bag filters, etc. handling ignition-sensitive dusts.
Inerting is the process of reducing the oxygen concentration in a closed system by supplying inert gas so that the atmosphere will be non-flammable/ non-ignitable.
Method
We perform this test based on EN 14034-4 2004: “Determination of explosion characteristics of dust clouds – Part 4: Determination of the limiting oxygen concentration LOC of dust clouds”.
Different amounts of the dust are dispersed inside a 20-litre explosion apparatus and ignited using a 2kJ chemical igniter. We repeat the test by gradually reducing the oxygen level inside the apparatus in steps, replacing it with inert gas, and varying the dust concentration until the LOC is found.
The LOC is inert gas-dependent due to the different heat capacities of inert gases. The LOC shall be reported stating the inert gas used
Benefit
The LOC is the reference parameter to know when applying inerting as a measure to prevent dust explosions.
This parameter is inert gas dependent and shall therefore be determined for the inert gas that will be added to reduce the oxygen level in the facility.
Limiting Oxygen Concentration test enquiries
Do you have any questions about the test? Please submit them through the form below.
