What different Pneumatic Conveying Systems are there?

What different Pneumatic Conveying Systems are there?

Here at STB Engineering, we have over 40 years of experience in pneumatic conveying systems. These systems are used to transport high volumes of granules and powders over long distances, having the benefit of being more versatile, hygienic and reliable than traditional mechanic systems. However, several different types of pneumatic conveying regimes exist which are suited for slightly different uses. Below we explain the five types of pneumatic conveying systems to help you choose the right one for your industry.

Dilute/Lean Phase

Dilute/lean phase systems can be divided into two pressure systems: positive and negative. Positive pressure or ‘blowing’ systems are the simplest of all pneumatic conveying systems. These use a blower or fan to deliver air into the pipeline, totally suspending the product in the air stream, before the powder is separated from the air stream at the other end by an air separator and filter.

Negative pressure systems, also known as vacuum systems, comprise of similar equipment but work in reverse, making them particularly suitable for carrying powder from multiple sources to a single point.

Medium Phase/Low Velocity

Medium phase, or low velocity, systems only partially suspend the product in the air stream with the rest travelling in a moving bed of material – in the base of the conveying pipe.

In medium phase systems, the concentration of product to air is increased and the air velocity is significantly reduced to around 8 -18m/s, making them particularly suitable for transporting more fragile materials. This is done via an intelligent speed control system which controls the output of the blower.

Pulse Phase

Pulse phase systems are used to pneumatically convey cohesive powders that would not be suitable for lean or medium phase systems. In these, the pulse pump separates the product into ‘plugs’ of powder and air using an air knife system, allowing the product to be more easily transported at even slower speeds of 4-10m/s.

This type of system offers many potential benefits, such as the ability to use smaller pipelines, low air consumption thereby reducing operating costs, and reducing degradation of the product.

Pulse/Dune Flow

Pulse flow or dune flow systems are a similar type of conveying system to pulse phase systems except they transport the product in ‘waves’ over a moving bed of material rather than separate it into plugs. As with medium phase systems, pulse flow systems are regulated by using an intelligent control system, making them ideal for conveying fragile granular products that need to be handled slowly and gently.

Dense Phase

Finally, dense phase systems are ideal for conveying fine powders and granules that have the potential to be fluidised by the transport air. Dense phase systems are characterised by their introduction of fluidising air to the powder through a porous membrane before transporting the fluidised product by pump.

Dense phase systems operate at low velocities typically 4 to10m/s and are specifically designed to reduce the amount of pipeline wear when transporting difficult or abrasive materials and for conveying at high capacity over long distances, making them great for enabling the best productivity.

Need a pneumatic conveying system? Contact us!

At STB Engineering, we have garnered specialist expertise in all these pneumatic conveying systems, producing bespoke solutions for the food, pharmaceutical, plastics, chemical and mineral industries. If you are interested in the above systems and would like to learn more about how they could work for your industry, please don’t hesitate to get in contact with us via our contact page.