Per Aredal, International Sales Director at FIREMIKS AB shares insights into water driven volumetric proportioners

Can you give a brief introduction to FIREMIKS?

Originally founded in 1979 as a Swedish family-based business – Firemiks AB is operated by the third generation, together with strong industrial partners.

Throughout the years, our focus has been to develop, manufacture and distribute our own line of water driven pump proportioning systems worldwide.

Our work method is to have the possibility to produce custom solutions to the individual needs of each client project, while also delivering regular models in accordance with international standards.

Can you explain how FIREMIKS foam proportioners work?

The proportioning of the FIREMIKS is based on the principle of positive displacement for both the water motor that is driven by the extinguishing water flow and the concentrate pump that is driven by the water motor and which injects the concentrate into the extinguishing water flow.

In this manner, the dosing relation is established by the volumetric relation of the water motor and the concentrate pump.

This dosing relation is not affected much by viscosity, up to a limit of course as is detailed in the units’ performance data.

The concentrate pump is connected to an atmospheric concentrate tank with gravity feed to the dosing pump.

Solely the extinguishing water is required to power the whole dosing system.

How do FIREMIKS systems accommodate the varying viscosities of firefighting foams?

The volumetric water motor design was conceived by us in the late seventies, and it is very compact for the flow it can take.

On a typical 3% unit, the water motor will take roughly 30x the volume of the concentrate pump, yet it is barely bigger.

Since the start we have constantly refined its design for better performance and reliability.

Like all pump design, it is all about the details and the execution.

Important is also our flexibility to adapt the design and sizing, so we can quickly match the water motor up correctly with a wide variety of concentrate pumps, each of which also has its specifics to take into account.

What viscosity handling challenges are there when transitioning to SFFF?

Regulatory bodies are driving the shift from PFAS-containing concentrates to Syntheitic Fluorine-Free Foam (SFFF) concentrates, prompting a reassessment of many proportioning systems for compatibility.

Various manufacturers offer SFFF foams with a wide range of viscosities, including very high-viscosity concentrates.

To select an appropriate proportioner, understanding the concentrate’s properties — whether it falls within a viscosity range of 1cP to around 5-6000 cP (measured using a Brookfield Viscometer Spindle #4 at 30 rpm) — or if it’s classified as very high viscosity is crucial.

In the past engineers have relied on being to calculate the flow of concentrate, but with these new SFFF that are often non-Newtonian in their nature, accurately and reliably calculating the flow behavior is much harder.

On devices that need calibration, the dosing might work in a specific set of circumstances, but as soon as one variable changes, it could fall out of calibration.

Then it is much better to rely on a system that by design can accommodate a wide viscosity range, like FIREMIKS.

How is FIREMIKS preparing for further advancements in firefighting foam technology?

Apart from the important transition from AFFF to fluor-free SFFF, which we expect will last for at least another 5-10 years.

We see more interest in lower dosing rates as 1% and even lower for example 0,3, 0,5% etc.

Also, the challenges to create good system capable of extinguishing Li-Ion batteries in an effective way is a major challenge for the whole fire-fighting industry.

Firemiks AB is well-prepared in this process to further develop our system if necessary to meet different concentrates requirements.

This article was originally published in the March 2024 issue of International Fire & Safety Journal. To read your FREE digital copy, click here.