A new or additional conveying system is often a substantial investment for a plant, and it’s important to make the right choice. For some applications, a dense phase system will be the best choice but for many others, vacuum conveying has more advantages.
In fact, so many plants are now choosing these systems that Grand View Research estimates the global market for pneumatic conveying as a whole will be worth over $30bn by 2022.
Let’s look at the three principal kinds of pneumatic conveying system that are found in industrial plants.
1. Positive pressure dilute phase system
This is often known by its more belt and braces name of a “blowing system” or a rotary valve conveyor. In this system, the materials are blown through the system to their destination.
2. Negative pressure dilute phase system
This is the opposite – a vacuum conveyor system where the materials are sucked through the system at fairly high speeds by means of a vacuum.
3. Dense phase system
The conveying pipe is filled with product which is moving along at a lower speed. However, much more of it can be moved at one time. This system is also known as a “pressure pot” system.
In practice, there is some overlap between these different types of system, and each type has its own advantages and disadvantages for the different products and ingredients that need to be moved.
Where hygiene is important, a vacuum system has a clear advantage because the products being moved are protected from any possible contamination. Vacuum systems http://www.aptech.uk.com/pneumatic-conveying-systems/vacuum-conveying/ are also clear leaders where a complex system with multiple pick up and delivery points, is in use.
For example, the different sizes of particles to be conveyed, their density, formulation and moisture content are all important. If toxic chemicals are being used, then a leak-proof vacuum conveyor may provide the safest method of processing the product.
It’s very much a question of assessing the attributes of the material being moved, the distance it has to travel and the complexity of the production system currently in use. It may be useful to talk to a supplier who can explain the full range of factors you need to take into account.