Preventing Explosible Dust Clouds
There are three major ways to avoid creating an explosible dust cloud without modifying the dust itself:

Add inert gas to the atmosphere
Ensure that the dust is outside of the combustible concentration limits
Add inert dust
Adding Inert Gas
Lowering the oxygen content in a process area/vessel can minimise the chance of a dust explosion, the easiest way to achieve this is to add an inert gas to the system. Possible choices include:

Nitrogen
Carbon Dioxide
Flue Gases
Water Vapour
Rare Gases
Halons were also previously used before their environmental impact was fully recognised. Usually nitrogen or carbon dioxide are the best choices, however these can be incompatible with some powders so it is advisable to use more expensive, rare gases. To actually introduce a new atmosphere to a process it is recommended that the system be slightly evacuated and then flushed with the inert gas until the pressure returns to atmospheric. This should be repeated until the desired atmosphere is generated. If a high pressure system is being used the n the inert gas can be simply pumped into the process vessels until the desired pressure is reached. Once the atmosphere is generated it is important to ensure that no air leaks into the process and that if gas is introduced with powdered feeds it is inerted too. Often partial inerting is used where total inerting would be too costly; this does not entirely remove the chance of explosion, but limits it massively.

Ensure that the dust is outside of explosible concentrations
This is extremely difficult to do in practice and is not generally used as a technique as the dust concentration in vessels is too unpredictable and very hard to measure accurately. By avoiding entrainment of the dust all of the time, thus making the concentration too high for explosion, this technique can be used. This can be achieved through careful plant and equipment design, but is difficult if very fine powders are involved. Also it should be noted that although this will help to avoid primary explosions, secondary explosions could still easily occur if the lying dust is sufficiently agitated leading to entrainment.

Add Inerting Dust
This method of avoiding forming explosive dust clouds is used successfully in coal mines. A layer of rock dust in the working area is entrained by the blast wave and, as it forms an incombustible atmosphere, it extinguishes the flame. This means of inertion is not usually available due to the contamination of product that it causes.