Koenen Apparatus Description
Test Purpose
This test is used to determine the sensitiveness of a material to the effect of intense heat under vented confinement. In this test, the material is placed in a steel container with an orifice plate. The test apparatus is then placed in a protective steel box, and heated at a specified rate. A series of trials is conducted using different sizes of orifices. A “+” reaction is determined by examining the container. Conducting three successive “-” reactions with an orifice plate size above that which produced a positive result concludes the test. This orifice is called the limiting diameter. The limiting diameter may be used to evaluate the degree of venting required to avoid an explosion in the process. The Koenen results can be coupled with the IVM-FC: a control volume thermodynamic model with vent panel parameters to estimate the required vent volume.
Equivalence
This test is equivalent to UN Tests 2 (b) in the UN Manual of Tests and Criteria
Key Parameters
| Key Parameter | Objectives | Origin | Specs |
|---|---|---|---|
| Confining medium (steel tube) | Vessel that can be used as evidence of sample reactivity should the venting capacity of the orifice be exceeded (excessive gas generation rate, orifice plugging, etc.) | Deep drawn from DC04, A620, or SPCEN sheet steel; 26.5 ± 1.5 grams mass, 75 °C 0.5mm length, 0.5 ± 0.05mm wall, and 30 ± 3 MPa quasi-static bursting pressure | |
| Orifice diameter | Provide varying degrees of venting capacity | 1mm orifice | |
| Heating rate | Provide a standard heating rate | 3.3 ± 0.3°K/sec for 27mL of dibutyl phthalate | |
| Maximum heating time | Sufficient time to react the material | 5 minutes |
Indicators
| Indicators | Detection Method | Assessment |
|---|---|---|
| Damage to the steel tube and/or closing device | Visual post-test examination of the tube and/or tube fragments | Limiting diameter (LD) is the orifice at which an explosion (three or more tube fragments) is obtained. The limiting diameter may be used to evaluate the degree of venting required to avoid an explosion in the process. |
Setup Example
No Explosion (-) Example Photo
Explosion (+) Example Photo
No Explosion (-) Example Video
Explosion (+) Example Video
