In industrial settings, dense-phase pneumatic conveying is a highly versatile and reliable way to transport powders and bulk solids, always with maximum safety and quality.

However, as with any other internal conveying system, lack of maintenance or improper use can cause various problems, resulting in production line shutdowns.

One of these problems is pipe clogging in the conveying line. This blocks the piping, which in many cases can happen suddenly and lead to serious consequences, especially economic ones.

In today’s article, learn about the main causes of clogging in dense-phase pneumatic conveying pipes, along with tips for solving this problem.

Why Do Dense-Phase Pneumatic Conveying Systems Get Clogged?

Widely used in industrial processes, the dense-phase pneumatic conveying system is a way of transporting powdered products using high pressure, low speed, and small volumes of air for movement.

By nature, this system is relatively gentle when carrying products, especially abrasive, fragile, or blended materials. However, this process is subject to sudden clogging or blockage of the piping.

This blockage happens when the energy supplied by the transport air isn’t enough to keep the powder moving, causing the particles to settle, reducing the cross-section of the conveying pipe until it eventually becomes completely blocked.

As a result, the transport air can no longer circulate inside the pipe, and all the solids that were in the conveying line before and after the clog location come to a stop, increasing the extent of the blockage.

Possible Causes of Pneumatic Conveyor Clogging

In an industrial plant using dense-phase pneumatic conveying, there are several causes that can lead to clogging and flow interruption, including:

• Air velocity isn’t sufficient at all points along the pneumatic conveying line, failing to reach the minimum transport velocity for the solid particles being conveyed;
• The motor may not reach a pressure high enough to overcome the pressure drop generated by the solids. In this case, a very high flow of solids leads to a high solids loading rate, which can result in a required pressure drop that the air motor (blower or compressed air) can’t achieve;
• The piping layout designed for the conveying process may create some flow instability in the pipe;
• Air leaks in the line. This reduces the actual air velocity below the minimum transport velocity at certain points in the line, which can cause clogging.

Best Practices to Prevent Pneumatic Conveying System Clogging

Clogging in the dense-phase pneumatic conveying system is an occurrence that industries should avoid. To achieve this, some best practices become essential, among which the following deserve the most attention:

Maintain and Clean the Equipment

To keep the equipment free of clogging issues, maintenance should be a priority and must be carried out according to the manufacturer’s guidelines. In addition to preventing clogging, maintenance also helps eliminate cross-contamination occurrences.

Cleaning the equipment is also important. When done properly, it eliminates any buildup that can form in the ducts and cause clogging.

Regarding maintenance, it’s also essential to check the pipes for leaks, which can alter air velocity and lead to pipe blockage.

Control Air Velocity

As we’ve seen, one of the main causes of clogging in dense-phase pneumatic conveying systems is airflow interruption. To prevent this, air velocity control must be careful and constant.

Keep the Layout as Simple as Possible

To prevent clogging, the project layout should be as simple as possible. Bends deserve special attention, since the flow of solids is disrupted and slowed down at each change in direction.

It’s therefore recommended to maintain a straight section of several meters after the material enters the piping and before the first bend. Consecutive bends should also be avoided.

In this way, dense-phase pneumatic conveying equipment is essential for many industrial processes. However, it’s important to remember that it must be cleaned and maintained to prevent clogging occurrences.

Keep following the Globe Systems blog and refresh your knowledge about this type of material transport.