What do we propose when we talk about a pneumatic transport installation?
A pneumatic conveying system is capable of moving solids in pellets or dust from one point to another, either vertically or horizontally, thanks to a air current that drags or sucks the flow through piping at a determined speed and direction .
The air volume and pressure needed to convey a flow is directly related to the distance to travel and the product to be conveyed.
The layout of this type of facilities has great implementation possibilities in an existing installation, since they can adopt the vertical or horizontal route with a great flexibility, requiring reduced space in plant.
In the design of a pneumatic conveying installation there are multiple variables for its correct operation that will depend to a large extent on the product to be transported. Their physical properties must be known, such as the size and shape of the particles, density, flowability, permeability, abrasivity, conductivity, etc.
There are different conveying types according to the product-gas ratio established for the solid convey:
Gravity conveying
The product flows by vertical duct thanks to its own weight and the gravity force.
Possitive or negative pressure conveying
The gas undergoes a positive or negative pressure that, when mixed with the product, conveys it to its destination.
Depending on the gas-product mass ratio, pressure and velocity, conveying can be established in dense, diluted or semi-dense phase.
Diluted phase
Large volumes of high velocity air are required for products that are not brittle or abrasive and with little risk of segregation.
Dense phase
The volume of air is much lower than in the diluted phase, but the pressure exerted on the fluid must be greater, since the solid is conveyed by thrust. It is widely used for fragile and abrasive products conveying.
The circuit of a pneumatic conveying system can be closed or open loop.
Open loop
The conveying gas is released to the atmosphere, previously separated from the product and filtered, renewing itself continuously at its feeding point.
Closed loop
The conveying gas is recirculated to the feed point after it has been separated from the solid.
