Grain destruction
Among grain destruction is defined as the disintegration of mineral , crystalline or amorphous particles into two or more fragments.
The process occurs in the industrial processing of mass products in the chemical and pharmaceutical industries, as well as in bulk goods and when handling granular materials or granules .
As a result of the grain destruction, the proportion of fines in the product increases drastically and at the same time the mean particle diameter decreases. As a consequence, the required product qualities are not achieved, the distribution range , the mean grain diameter , coarse and fine fraction , filterability , flowability must be mentioned here .
Grain destruction occurs increasingly in different types of centrifuges , which exert such high mechanical loads on the particles that their breaking point is exceeded, as well as when pouring . There is also grain destruction through thermal ( heat , frost ), hygroscopic ( moisture , dryness) or chemical influences.
Example:
- Damage to particles in the manufacture of sensitive chemical products, for example adipic acid
The grain destruction as a phenomenon at the level of the individual particles must be distinguished from other effects, for example
- Product damage during storage:
- "Crumbling" pills and tablets that make them unusable
- Abrasion from wood pellets that interfere with the burner control
- or when using the finished product:
- Disintegration of bulk material into thermal insulation due to penetrating moisture and subsequent frost as structural damage
There are four possible causes for the grinding process (which is the destruction of the grain):
- Pressure or pressure / thrust
- Bulging
- Shear
- non-mechanical energy supply
Example of non-mechanical energy supply:
- Disintegration of granular black powder in superimposed pyrotechnic articles , with extreme risk of uncontrolled behavior of the effect
literature
- Michael Bentz: Influence of product properties and operational settings on the process result in pusher centrifuges with special consideration of particle destruction . Shaker 2009 [1] .