The design of bulk materials handling systems involves not only the choice of the type of technology, but also the ability of that technology to be integrated into existing production systems, thus ensuring continuity.

The benefits of using a new solution become the driver of a decision-making process that can be undertaken by both manufacturing companies and system designers.

On the one hand, the end user wants to achieve a return on production and a competitive advantage; on the other hand, the systems engineer must design a complete system in which each component integrates seamlessly with the others. The ability to meet this multitude of requirements in a well-structured yet flexible manner is the key to choosing a supplier of bulk materials handling solutions today.
Let us take a closer look at the different applications of these solutions for manufacturing companies in all industries and for systems engineers.

Manufacturing companies

End users of powder and granule handling systems are often faced with issues relating to conveying or processing raw materials. Important factors to consider include: economic commitment, product and production environment characteristics, and compatibility with technologies already in use.
Previous experience and in-depth knowledge of the product are the basis for an informed choice of the most suitable handling system.
Starting with an initial technical consultation phase, Air-Tec System applications are designed, built, and installed according to the intended use. The handling systems, whether extensions of existing installations or new solutions, are complete and ready to use.

Systems engineers and engineering companies

They are specialists in the design of even the most complex systems that include various processing stages: from storage and conveying to dosing and mixing of bulk materials. These are complete systems based on the concept of automating production processes by combining different technologies.
Each part of the system must be selected taking into account the characteristics of the equipment, the intended end use, and the need to fulfil the economic agreement entered into with the customer. The solutions aim to develop synergies between the various existing systems by properly interfacing them.
It is essential that all selected technologies can be fully interfaced to ensure an integrated production flow. Air-Tec System’s systems are specifically designed for efficient data exchange. Entire system sections, including the necessary accessories, are adapted to the context in which they are to be used.

Air-Tec System offers complete solutions and accessories to meet the needs of both end users and systems engineers.

As part of the Transition 4.0 project in support of the digital transformation of companies, there are still a number of beneficial opportunities.
Today it is more important than ever to be resilient in the face of dynamically changing economic conditions.

Digitalising your company means not only taking advantage of available tax credits, but also gaining full control over your production processes through the ability to collect automated data in real time.

Pneumatic conveying systems as enablers of Industry 4.0 change

Pneumatic conveying systems are able to connect with each other and with the other components of a production plant in order to create a perfectly integrated processing flow. This makes it possible to achieve a high level of efficiency and optimise production costs.
These machines, developed for data exchange and remote assistance, are among the enabling technologies for Industry 4.0.

Let’s take a detailed look at the requirements for their inclusion among the functional assets for the technological and digital transformation of companies, according to the Transition 4.0 model:

Applications involving pneumatic conveying alone are not covered by Industry 4.0. standards; however, when they are integrated into systems that comply with the standards, they become part of the production process and acquire the necessary requirements.

In the planning stages of a production system, the advice of Air-Tec System engineers is aimed at ensuring effective integration to fulfil regulatory requirements.

Pneumatic transport sizing: find out the right technology for your product

To select the best system for your needs, you should consider a number of factors including material properties, desired throughput and conveying distance.

Other factors to consider are for example air pressure, air flow and velocity.

Typical pressure values for dilute conveying systems are:

ΔP: from + 0,2 to + 0,8 bar for pressure systems
from -0,2 to – 0,5 bar for vacuum systems

Typical pressure values for dense phase pneumatic systems are higher, ranging between 0,5-5 bar.

Air flow, which is the amount of compressed air needed to obtain the speed for the conveying process, is affected by three factors:

• Material properties
• Conveying distance
• Throughput

If you handle bulk materials with different physical and/or chemical properties, you might be familiar with segregation issues.

Whatever your industrial sector is (food industry, pharmaceutical, chemical, etc…), it is important that the mixture transported remains homogenous and uniform.

Taking a binary mixture as an example, we can have three degrees of blending:

Therefore, you can understand why segregation is such a common issue when handling material mixtures. In many applications, it’s almost impossible to obtain a uniform and homogenous blend.

Dense phase pneumatic conveying can overcome efficiently this issue. Dense phase systems use approximately 30 litres of gas to move 1 kg of product but, due to the high pressure inside the pipeline (more than 1 barg), powders form compacted plugs which are then carried along the line. This does not allow fine particles to segregate from the others.

We have tested more than 500 powders in our laboratories and we have come to the conclusion that only dense phase pneumatic conveying can avoid powder stratification.

Francesco Pozzi
Head of Air-Tec System Research and Development Department

The selection of a pneumatic conveying system for a particular application involves consideration of numerous parameters associated with the conveyed material and the conveying conditions.

When considering which system to use, we need to take into account the material to be conveyed at a specified flow rate over a given distance. Other factors that can be used in the decision-making process are power consumption, and hence system operating costs.

Dense phase or dilute phase?

Materials can either be conveyed in batches through a pipeline, or they can be conveyed on a continuous basis, even 24 hours a day if necessary. In batch conveying, the material may be handled as a single plug if the lot size is relatively small.
If the batch size is large, two possible ways  of conveying are possible.
If the material remains in suspension in the air through the pipeline, it is referred to as dilute phase conveying. If the material is conveyed at low velocity in a non-suspension mode, we refer to as dense phase conveying.

Dilute and dense phase systems are the two most common technologies. They differ from the concentration of the products inside of the pipeline.

In dilute phase the particles are held in suspension in the air as they are blown or sucked through the pipeline. A relatively high velocity is required and so power requirements can also be high. There is virtually no limit to the range of materials that can be conveyed but some considerations must be done about friable and abrasive materials. In fact the contact between the product and the pipeline, and particularly the bends, could degrade the particles.

In dense phase pneumatic conveying the air pushes a considerable quantity of product inside the pipe, generating an actual plug.
The possibility to control the pressure of the fluid acting on the plug allows to give the minimum power necessary to move it.

Conveying velocity

In dilute phase conveying the air velocity in the pipeline is very high, usually in the range of 16-20 m/s at the start and final speeds not exceeding 30 m/s on the outlet.

For dense phase conveying, air velocitiy can be reduced to 3 m/s. Low speed allows to reduce the breakage of delicate products and the wear of the pipes when they are crossed by abrasive products.

The best-known abrasive particles of natural origin include corundum, quartz, silica, diatomaceous earth and salt. Among synthetic abrasive particles, glass and some types of oxides are also well known.

How the pneumatic transport of abrasive products works

When designing a pneumatic conveyor system, the chemical composition of the abrasive material needs to be taken into account since it will affect its behavior when in contact with another material.

If you need to handle an abrasive powder, besides choosing a low-speed transport with full pipeline, you can also opt for specially designed curves, made of suitable alloys to prevent wear over time.

Francesco Pozzi
R&D Manger at Air-Tec System

When you choose metal powders pneumatic conveying you using a technology that can guarantee safety and efficiency.

When disposing exhausted batteries, you need to handle lithium, cobalt or other substances that may be potentially harmful for the environment. For this reason, it is important to follow every step of the disposal process to ensure compliance with legal requirements. These substances cannot be released out in the environment and they need to be handled with caution since they are highly corrosive powders.

How the pneumatic transport of powders in recycling batteries works

It is only in recent years that dense phase pneumatic transport for powders has been applied to the disposal of exhausted batteries.
In fact, it is with the increased use of electric cars and electronic devices in the last decade, that the recycling market of metal powders has become more and more important.

The recycling process of metal powders recovered from exhausted batteries involves the separation of each substance, which will be further treated in order to be reused for the benefit of electric mobility and the environment.

Why choose dense phase pneumatic conveying system?

Because it delivers a great deal of benefits!

The metal powders pneumatic conveying is composed of a completely closed structure able to avoid the dispersion of material into the environment.
In our dense phase pneumatic conveying system of powders, safety is essential.

Recycled metals powders from exhausted batteries represents over 40% of the total production of lead in Italy and 37% of the national demand for metal (Source: automazione-plus.it). This market presents good opportunities.

As far as the abrasiveness of these powders is concerned, thanks to the low speed of a dense phase pneumatic conveyor, the wear of the pipes is reduced to a minimum. In this way high performance levels and reduced maintenance costs are assured.