It's like drinking from a plastic bottle with a straw, the air rushes into the bottle through the open area around the straw. If you were not to use a straw and sucked the air out of the bottle with your lips sealing the opening, you can create enough vacuum to start collapsing the plastic bottle. The same thing can easily happen to the silo if the air is cut off during discharge. The silo will then pull together and perhaps even collapse. If you are experiencing moisture and mould it will build up and drip into the clean flour and form block spots in your production.
Infestation becomes a real concern.
Down time for cleaning the silo, fumigation, lost production all have their cost, not to mention lost production due to bad batches or product recall. Sugar Silos Sugar silos also have the same problems with moisture condensing on the inside walls of the silo. Sugar dust and water make an incredible build up which will also seal the filter and the danger of creating a vacuum inside the silo also exists here. A sugar silo must also be designed with mass flow characteristics. Moisture within the product will also condense on the silo walls and start building up sugar layer.