Left: enclosure schematic — colour shows internal pressure, panel opens once burst pressure is reached. Right: pressure vs time.
Grain silos, dust collectors, spray-drying chambers and many other industrial vessels are designed against internal gas or dust explosions using a well-established process-safety calculation: the cubic law, (dP/dt)_max · V^(1/3) = Kg, relates the maximum unvented rate of pressure rise to vessel volume and a mixture-specific deflagration index Kg. This simulation lets you tune vessel volume, mixture reactivity and vent-panel sizing to see how much a properly sized vent reduces the peak pressure the enclosure actually experiences compared to an unvented worst case.
An enclosure whose colour reflects internal pressure, with a vent panel that opens once burst pressure is reached, alongside a live pressure-vs-time chart marking the vent's burst-pressure threshold.
Set Vessel Volume, Deflagration Index Kg, Vent Area and Vent Burst Pressure, then watch the pressure rise, trigger the vent panel, and see how much lower the peak "reduced pressure" ends up compared to the unvented case.
Because the cubic law scales the maximum rate of pressure rise with the inverse cube root of volume, a much larger vessel actually gives more time for a vent panel to react and relieve pressure — which is why vent-sizing standards specify larger vent areas for smaller, faster-pressurising enclosures, not the other way around.
It is the empirical relation (dP/dt)_max · V^(1/3) = Kg used across explosion-protection standards to relate the maximum unvented rate of pressure rise in a vessel to its volume and a mixture-specific deflagration index Kg, letting engineers size vent panels without re-testing every vessel size individually.
Kg is a standard tabulated safety parameter characterising how quickly a specific gas or dust mixture burns in a standard test vessel — a higher Kg means a faster, more energetic pressure rise for the same enclosure volume. It is used purely as a safety-engineering input, not as information for creating hazardous mixtures.
Once internal pressure reaches the panel's burst pressure, it opens and lets hot combustion products escape, relieving pressure that would otherwise keep building — a larger vent area and a lower burst-pressure setting both let relief begin sooner and proceed faster, lowering the peak "reduced pressure" the vessel structure must withstand.
The same cubic-law approach and vent-sizing logic is used across combustible dust hazards (grain, flour, wood dust, many powders) in process industries, which is why explosion-venting standards like NFPA 68 and EN 14994 cover both gas and dust deflagrations with the same underlying framework.