The operational efficiency of pneumatic conveying systems in bulk processing plants depends on a number of factors, including air velocity and pressure drop, the characteristics of the product being transported (such as particle shape and bulk density), and the overall pipeline design.

Even after carefully considering all these factors, optimal efficiency is unlikely to be achieved if the transition points between your process equipment aren’t fitted with quality flexible connections that seal 100%.

The Crucial Role of Quality Flexible Connectors

Whether you are using positive or negative pressure, the efficiency of your overall production line can only be as good as the flexibility, seal and durability of the flexible connectors that allow your product to flow between pieces of process equipment.

Here’s why the choice of flexible connector is imperative for efficient pneumatic conveying:

The fundamental concept of pneumatic conveying is using air to push or pull product along an enclosed pipe.  The key here is enclosed: every transition between a piece of pipe and process machinery must be sealed for the air flowing through the line to maintain its optimal flow pressure.

If air is leaking out - or being sucked in - through a flexible connection point, the product flow is going to be affected, and energy will be wasted, generating higher pressure to maintain the flow rate needed.

Pneumatic conveying systems operate in dynamic environments with constant vibrations and movements. Flexible connectors need to act as shock absorbers, mitigating stress on the system caused by these vibrations.

This not only ensures a smooth and continuous material flow but also minimizes wear and tear on equipment itself, extending the lifespan of critical components.

A 100% seal in a process line is vital for maintaining the hygiene of both the plant and product itself, and this is most evident at the transition points.

In positive pressure applications, powder will be forced through any small gaps or crevices in a flexible connection and out into the factory environment. This creates a hygiene risk with the potential for bacterial growth to occur at product build-up points in the crevices themselves.

Powder leakage is also a substantial safety concern, with dust settling on plant equipment surfaces a key risk factor in combustible dust explosions.

If you operate using vacuum conveyance, quality flexible connectors create a reliable seal, preventing contaminants from being sucked into the system, protecting the integrity and purity of processed powders. This is of paramount concern in industries such as pharmaceuticals and food processing.

The abrasiveness of the transported product and the velocity at which it is flowing will play a big factor in the amount of wear on any flexible connector. The amount of wall contact a connector has with the product will also play a part. Horizontally installed connections, for example, will naturally experience more wear than a vertical connector, as gravity will mean more wear occurs along the bottom portion of a horizontal connector. It’s always advisable to rotate such a connector regularly to extend its life – but the most important factor is to choose an easy-to-fit connector made from a durable, abrasion-resistant material.

Connectors made from materials that are not abrasion-resistant or are easily torn will require frequent replacement, which means shutting down production. If the connectors are fastened with hose clamps or need considerable manual adjustment to get the correct fitment, this will further increase production downtime each time they are changed.

What Is The Best Flexible Connector For Pneumatic Conveying Applications?

The BFM ® fitting system has become the industry standard for flexible connectors due to its reliability and performance in all applications, including pneumatic conveying.

A BFM® fitting comprises two spigots, which are steel adaptors that are welded to your equipment and a snap-fit, flexible blue-band connector that sits on the inside of the shaped portion of the two spigots, keeping it securely in place.

Specifically tailored for bulk powder processing applications, the BFM ® fitting stands out as the superior option for ensuring optimal performance, hygiene, and ease of use in pneumatic conveying systems due to the following factors:

The BFM^® fitting system is engineered with a groundbreaking design featuring a snap-in flexible sleeve that ensures a dust-tight and contaminant-free connection.

Unlike traditional connectors that use gaskets, clamps, or O-rings, the BFM® system employs a flexible sleeve that snap-fits into place on the inside of the pipe with no gasket, ensuring a 100% dust-tight seal. This prevents leaks and product contamination and eliminates the risk of gasket failure, reducing maintenance requirements and downtime.

Seamless Material Flow:

The BFM^® fitting system's smooth, crevice-free design ensures an uninterrupted flow of bulk powders, significantly reducing the need for frequent stoppages and cleaning. Unlike clamp-style connectors, it seals cleanly on the inside of the pipe, eliminating potential contamination zones.

Positive pressure pushes the snap-band outward, further improving the seal and preventing dust from escaping. The strong, pressure-resistant seal will also prevent air and contaminants from being sucked inwards under vacuum, with a special ‘Tool Release’ option for enhanced performance under negative pressure.

One of the most significant advantages of the BFM® fitting system is its swift and straightforward changeout process. The BFM® system's snap-in, snap-out design facilitates rapid changeouts, minimizing downtime and optimizing production schedules.

When replacements are required, operators can swiftly remove and refit the flexible sleeve (often in less than 30 seconds) without requiring maintenance staff to disassemble the entire system. The pre-set sizing of the BFM® fitting connectors means no manual adjustments are required, minimizing downtime and maximizing operational efficiency.

Crafted from high-quality materials, the BFM^® fitting system is designed to withstand the abrasive nature of bulk powders and the rigours of industrial environments. The most widely used Seeflex range of products is manufactured in a proprietary method so that they are extremely abrasion-resistant and won’t tear like many silicones or other urethanes.

This durability ensures a longer lifespan for the connectors than virtually any other comparable products, providing considerable payback with reduced replacements and production downtime.

The BFM^® fitting system adheres to strict industry standards and has achieved international health and safety compliance requirements such as 3A, FDA and ATEX. This ensures that bulk powder processors can trust in the performance and give peace of mind regarding safety and quality.

The BFM® fitting system is trusted by major global manufacturers, including Nestlé, Mondelez and Unilever, among others, to provide the most reliable, safe and efficient flexible connector system in plants worldwide.

Find out more about how the BFM® fitting system can improve your process efficiency.

Article Author, Matt Bailey is a mechanical engineer and the Technical Lead for BFM® Global, the manufacturer of the BFM® fitting system. He has been responsible for BFM®'s  product development, testing and compliance programme for over 5 years.