Finding the Right Pneumatic Conveying Process for Your Application

At Nol-Tec Systems, we offer numerous solutions for pneumatic bulk material handling. Looking at our product information, you’ll see terms like “dense phase conveying” and “dilute phase conveying”, as well as references to vacuum and pressure. What’s the difference between these conveying options? And how can you know which conveying method is best for the materials you work with? Read on to learn more.

Dense Phase Conveying vs. Dilute Phase Conveying

Dense phase pneumatic conveying is preferred for bulk materials that are friable, prone to smearing, or otherwise fragile. This conveying method uses a low volume of air at high pressure to move large quantities of material. It is a far more gentle process—as material moves through the system’s tubes or pipes, it will roll or flow gently along the sides and around corners, minimizing damage to the material and the equipment.

Dilute phase pneumatic conveying is better for more durable materials that won’t break apart as they go, or for applications where damage to the material is acceptable. This method uses high volumes of air at high velocity—between roughly 3,500 and 5,000 feet per minute—to entrain bulk materials into the air stream and carry them along. Impact with the sides and corners of system tubing can cause damage to materials and increase wear on the equipment. Dilute phase conveying requires less equipment and is therefore the less expensive option.

Conveying with Pressure vs. Conveying with Vacuum

When conveying bulk materials via pressure, you are essentially pushing the material through the system with air pressure. It is effective over very long distances, but tends to cause more damage to material than vacuum conveying does. Most of the pneumatic conveyor systems Nol-Tec provides use pressure conveying.

When conveying via vacuum, materials are pulled through the system, just like a vacuum cleaner pulls dirt out of your carpet. It is a very gentle way to convey materials and causes minimal damage, making it ideal for fragile or friable materials. Vacuum systems are recommended when transporting hazardous materials, because any leaks that may occur would pull external air into the system, rather than allowing the material to pour out. However, vacuum systems are limited to roughly 200 feet between Point A and Point B.

A dilute phase vacuum system can cover the most distance of any pneumatic conveyor, but will also cause the most material attrition. A dense phase vacuum system offers the gentlest pneumatic conveying possible, but has limited reach.

Nol-Tec’s Custom Designs Match Process to Application

Every pneumatic conveying application is different. The distance to be covered, the material being conveyed, the rate at which it must move, and other factors must be considered when putting together a pneumatic conveyor system and choosing between dense or dilute phase and vacuum or pressure.

That’s why Nol-Tec Systems sells custom designs. You know your materials and where you need them to go – we know how to get them there in the best way possible. We utilize extensive testing to determine how the pneumatic conveyor will perform in your facility for your application, and assemble standard components into a custom configuration that will meet your unique needs.

Contact us today to discuss your material requirements and to get started on a pneumatic conveyor system for your facility.

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