Filling & Emptying Silos with Pinch Valves

A silo is a structure or vessel for storing bulk materials. Silos are used in agriculture to store grain, powders, fermented feed (known as silage) and animal slurry.

Silos are used by other industries for bulk storage of materials such as coal, cement, sand, woodchips, metal waste, food products and sawdust.

The working principle of a silo is always the same: The large vessels are filled with a product from the top which is usually fed and pumped from a pressurised tanker. An indication leveller informs a signal when the silo is full. The product inside the silo is often stored for different amounts of time, and then released when required through a pipe or opening at the bottom of the silo which is controlled by a valve.

Bridging, Caking & Rat-Holing in Silos

The funnel shape of a silo helps to guide the product down and out of the opening at the bottom. However, due to temperatures and moisture, the product can become clogged in different areas of the silo as it continues to try to be released.

The term rat-holing is used to describe a narrow tunnel formed by the product, with the rest of the product becoming stuck. This causes insufficient flow of material, thus slowing down production.

Bridging indicates that the product slows down due to friction on the inner walls of the silo, binding the particles together and forming an arch above the opening. Again, causing insufficient flow or in some cases completely stopping the flow of material.

Caking is used to describe the build up of sticky product on the inside of the silo walls, reducing the amount of surface area for the product to pass through and causing blockages.

Improving the Flow of Product in Silos

To prevent the above issues, AKO UK provide the ideal solution. With vibrating aerator pads installed in various positions around a silo, usually towards the bottom, the product is encouraged to move downwards from the effective vibrating motion.

This technique is known as aeration and enables the free flow of silos, hoppers and bins with no blockages or clogging.

See how aerator pads assist silo applications in many different industries by reading our customer case studies and more information.

Pinch Valves for Filling & Emptying Silos

Pinch Valves are an important working part of any silo – they control and dose all of the different processes involved with filling and emptying. The specification of a Pinch Valve can be altered depending on the product inside the silo. For example, AKO offers food grade pinch valves for processing food, and special abrasion-resistant pinch valves for highly abrasive media.

powder silo system
VMC Stainless Steel Brewery Valves

Help other Valve users in your sector

Do you successfully use AKO Pinch Valves within your application?

Help us to help other valve users run their sites more smoothly with the simplicity and reliable performance of the Pinch Valve, by sending a completed questionnaire and photos to [email protected]