Stainless Steel and Aluminium Silos for the Food Industries

There are a number of issues to consider when purchasing silos for the bulk storage of powdered foodstuffs. These are listed below:


1) Storage Volume and Silo Shape

The storage capacity of a silo is primarily determined by its height and diameter; however consideration needs to be given to how the silo is filled and emptied. When powder is loaded into the top of a silo, it forms a cone. Therefore, additional free space called ullage or headspace is required to accommodate this cone. The space required is determined by the powder's flow characteristics. Barton Fabrications will provide advice on necessary heights for this section during silo design.

At the bottom of the silo the outlet diameter and material flow characteristics of the powder determine the angle of the cone shaped outlet section. Barton Fabrications' 30+ years design experience ensures the optimum angle is used for free flow of feedstock from the outlet. Having the correct silo cone angle together with appropriate discharge aids prevents 'dead zones' (where the material doesn't move) or bridging (where the material hangs in the silo).

The Barton Fabrications Silo Capacity Calculator tool can be used to calculate an approximate silo storage capacity.


Silo assembly tower prevents contamination
Silo assembly tower prevents contamination
2) Contamination

It is essential that food storage vessels do not contaminate the stored product even during prolonged contact with the silo wall. Barton Fabrications only use high quality stainless steel or aluminium and silos are manufactured inside a purpose built tower and fabricated using TIG welding to ensure welds are clean and contamination does not occur. In addition all silos are cleaned and sealed before delivery to avoid contamination during transit.


3) ATEX and Explosion Protection

Many powdered materials are explosive and foodstuffs are no exception, therefore, most powder storage silos in the UK must be designed to be ATEX compliant. At Barton Fabrications, the silo itself is designed to withstand the high internal forces generated in the unlikely event that an explosion occurs. As part of design compliance, explosion vents are installed at the top of the silo to release the excess pressure in a controlled manner ensuring that both plant and personnel are protected.

For more information on ATEX compliant silos contact Mark Barton on sales@bartonfabs.co.uk, or download the SHAPA Practical Guidance for Suppliers and Operators of Solids Handling Equipment for Potentially Explosive Dusts.


Twin walled construction with lagging reduces condensation
Twin walled construction with lagging reduces condensation
4) Condensation

Ambient temperature changes can cause condensation. If this occurs inside the silo the foodstuff can be spoilt or clumping can occur preventing even discharge and leading to the need for additional routine cleaning. To reduce these problems Barton Fabrications is able to produce double skinned silo walls with lagging in-between the walls. This type of silo construction is proven to reduce problems associated with condensation.


Silo load cell
Silo load cell
5) Silo Content Measurement

Monitoring stock is an important part of inventory management and Barton Fabrications silos can be supplied complete with Applied Weighing load cells and remote telemetry systems. For more information contact Mark Barton on sales@bartonfabs.co.uk or see the Applied Weighing website.


Safe working environment within the Penthouse
Safe working environment within the Penthouse
6) Maintenance

Silos themselves are relatively maintenance free however units such as explosion vents, filling nozzles and dust collectors need routine checks and cleaning. For this reason Barton Fabrications has created its Penthouse silo design. This includes an enclosure at the top of the silo to provide a safe working environment for maintenance activities.