Silos are manufactured in a range of materials subject to their end use including concrete, coated steel, aluminium, stainless steel and GRP/plastic. Generally in the food and plastics industry the typical choice is aluminium and although stainless steel does have some use in foodstuffs storage it is more commonly seen in the pharmaceutical industry.
Aluminium is an ideal material used to manufacture silos. It is strong, lightweight, self-supporting, easily welded and its strong oxide layer ensures it doesn’t contaminate the material being stored with no requirement for additional surface treatment or maintenance issues.
The starting point for any silo installation is detailing the storage materials and where the vessel, or vessels, are to be sited. A silo sizing tool is provided to give an approximate idea of silo size and content for different materials.
The nature of the material to be stored must be assessed in relation to the explosion risk it presents and how that risk can be controlled / mitigated. The legislation covering this falls within ATEX and is implemented in Great Britain through the DSEAR and EPS regulations. Note plastic feedstock generally does not represent an explosion risk and therefore silos do not need to be ATEX compliant.