Using the vacuum or negative pressure to convey powders and other bulk materials in a processing line has many advantages; however, there are important factors to be aware of to properly design a pneumatic conveying system.

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1. Bulk density

Knowing the pounds per cubic feet of the powder that your system is conveying is essential in calculating the size of the conveying line and therefore the velocity of the vacuum producer. Lighter powders need larger receivers, while materials with higher bulk density require a higher transport velocity.

2. Conveying distance

How far up or down and along the conveying line do your powders need to be moved? How many 45° or 90° sweeps, either horizontally or vertically, will form elbows in the tubing? Can these be reduced, as powders do not flow like liquids? A vacuum conveyor cannot power vertical runs in excess of 12-15 feet without powder falling back down the line.

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3. Material characteristics

There may be many different particle shapes and sizes that determine the size of the receiver and filter assembly. Is the material free-flowing or abrasive or combustible? Does it absorb moisture? Does it create a smoke like talcum powder? Work with a specialist 
Vacuum Conveyor company to answer these questions and perfect the design for your system.

4. Receiving materials

Define how materials will be introduced into the vacuum conveying system and pay attention to dust control. Bulk bag unloaders can be incorporated into the enclosed vacuum conveying lines and filtered before being conveyed into the process. The frequency with which materials will be fed into the conveyor will influence the 
downstream equipment you require.

5. Headroom requirements

Your existing building may not have been designed for vacuum equipment and headroom could be limited. You will need at least 30 inches headroom for the smallest conveying system to allow for maintenance and inspection.

6. Construction materials

The materials to be used making the vacuum conveying system will be chosen based on the properties of the powders to be moved. Metal is typical, as plastic can cause static and contamination. For food and medical grade processing, stainless steel is often the material of choice.

Whatever the purpose of your vacuum conveying system, consider these six factors when specifying the design and build for a successful result.

 

Published by Sunil Pandey