Why agglomeration is only part of the Flexomix Story
Over the decades, the Flexomix has earned a strong reputation as an effective agglomerator. However, agglomeration is only part of the story. In this article, Hosokawa Micron’s Wouter Sloot discusses the broader capabilities of the Flexomix. From homogeneous mixing of dry powders to mixing powders with fluids, this versatile, high-impact mixer has repeatedly proven itself across a wide range of powder and powder-fluid applications.
The Flexomix has been on the market for over 40 years. In that time, the machine has become widely regarded as a dependable, high-performance mixing solution. “At Hosokawa Micron, we are continuously further developing this technology for new market requirements and applications,” states Wouter Sloot, Application Engineer (Team Food & Feed).
Having worked closely with the Flexomix for more than six years as a process technologist before he became an application engineer, Wouter has first-hand knowledge and experience of this machine’s versatility. “Besides being an agglomerator, the Flexomix is first and foremost a continuous vertical mixer. It is capable of achieving a highly homogeneous mixture of different powders with fluids,” he states. “In fact, more than half of these machines currently in use around the world are being utilized for mixing rather than agglomeration.”
Short mixing time and wide choice of mixing speeds
So what makes the Flexomix so effective as a continuous mixer? “This machine achieves almost instantaneous mixing, with a residence time in the mixing chamber of roughly just one second. Meanwhile, thanks to the broad bandwidth of possible mixing speeds – from 500 RPM up to 4,800 RPM – the Flexomix delivers a very impressive mixing result for a wide variety of products. The combination of short mixing time with a wide range of mixing speeds makes the Flexomix truly unique,” explains Wouter.
Small footprint and low energy consumption
“Thanks to its exceptionally high throughput, we can maintain an energy-efficient and compact design. This results in low power consumption, which is not only often a process requirement, but also good from a sustainability perspective. Meanwhile, the short residence time allows a small mixer resulting in a small physical footprint. For example, the footprint of our biggest Flexomix – which is capable of mixing 40,000kg of product per hour – is not much larger than a domestic washing machine,” he continues.
Customizable in line with application requirements
Hosokawa Micron designs each Flexomix application in close collaboration with the customer. Besides adjusting the mixer speed, the Flexomix can be configured according to a wide variety of requirements to achieve the desired mixing result. Options include adapting the mixing chamber, tailoring the rotor design or adding fluid/steam injection nozzles.
Mixing chamber
The Flexomix is equipped with a self-cleaning mixing chamber to prevent the product from sticking. Depending on the customer’s requirements, the wall can be made from various materials. This wall is often flexible, but in the case of non-sticky materials a fixed stainless steel mixing chamber may be sufficient for the customer’s needs.
Rotor design
Similarly, the rotor configuration inside the mixing chamber can be tailored to achieve the optimal mixing result. Both the design and the position of the mixing knives mounted on the rotor can be adjusted to modify their interaction with the product. Together with the mixing speed, this offers maximum flexibility to align with the specific process requirements.
Fluid injection
The Flexomix is suitable for mixing a wide variety of fluids. Examples include molten fats that are solid at room temperature, water-based solutions with viscosity comparable to mayonnaise, or gases such as steam. To accommodate this variety of fluids, Hosokawa offers a broad selection of nozzle designs. “We can even develop new application-specific nozzles,” adds Wouter.
In-house test facilities
Testing is a very important part of the design process of every Flexomix application. “Due to the wide range of requirements, we run trials using the customer’s products at our in-house Test Centre. This enables us to test the Flexomix settings and identify the best mixer setup to achieve the desired results. Some applications entail working with a fixed recipe, but in others we push the boundaries during testing, such as by adding as much liquid as possible,” he comments.
Multiple applications
Just some examples of the wide range of applications for which the Flexomix is already being utilized include:
- Dairy: mixing powders and adding a lecithin coating
- Bakery: mixing of multiple powders with the addition of oil
- Detergents: mixing of powders with multiple liquids simultaneously
- Feed products: mixing powders with molasses
Potential to improve legacy processes
Beyond these applications, Wouter also sees many opportunities for further innovation: “The versatility of the Flexomix means that virtually any powder can be mixed with the complete spectrum of fluids – steam, water, oils and liquid solutions – in any degree of viscosity.”
This is opening up interesting possibilities. For example, liquids that are too viscous for spray-drying can be mixed with dry powder. The Flexomix produces a granular mixture which can be dried with an alternative technology, improving energy efficiency.
Wouter sees more potential benefits for the Flexomix in the market. “Thanks to its versatility to mix powders with powders and powders with liquids, we see a chance for the Flexomix to improve legacy mixing processes. By enabling all powders and liquids to be mixed in one relatively small mixer, it reduces complexity, energy consumption and cleaning time. We are always open to hearing from companies who share our excitement for exploring such opportunities together,” he states.