Industrial Fire Journal - Fire & Rescue - Hemming Group Ltd
Beautifully proportioned
Published:  09 February, 2015

A foam proportioner that is simple to use and requires no power for its operation? Jose Sanchez de Muniain finds out about a simple and modern technology that is set to change the market – and it will be on show during Interschutz in Hanover, Germany, in June.

Per Aredal is the Sales Director of Firemiks AB, a family-based manufacturer in Stockholm that has been designing and marketing water motor driven proportioners used in Europe and worldwide since 1979. In 2010, the company restarted and decided to not only manufacture its own proportioners, but also to market and distribute them under a new brand name. To this end, the company designed and built a further developed proportioner that took into account advances in engineering technologies. The end result is FIREMIKS, a proportioner that requires no supplemental energy to work – it only needs the pressure from the water to mix and discharge the foam/water mixture.

The response from the market has been an eye opener for Per Aredal: ‘The interesting thing that people have been saying is that this will become the new industry standard and we are seeing this shift too. We believe the bladder tank proportioners will disappear from the market more and more in the next five to ten years, maybe also the in-line balance pressure proportioners, which are just too complicated to function efficiently.’

In line balanced pressure foam proportioners require foam concentrate to be supplied at a higher pressure as the pressure at the water inlet. This pressure is created by an electrical or fuel driven pump. They therefore need additional equipment (eg a balance valve) which has to be pre-calibrated to the right pressure to match both the foam pump pressure and the water pressure.

Bladder tanks are another form of balanced pressure proportioners widely used in fixed fire systems throughout the world. They consist of a steel pressure vessel containing a bladder (eg made of elastomer) filled with foam concentrate. The system becomes operational when water is pumped into the steel vessel: the pressure of the water squeezes the bladder and forces the concentrate through piping into a ratio controller. As the foam concentrate pressure is higher than the pressure at the ratio controller, the foam starts flowing towards the water and mixing at a calibrated rate, which is dependant on the water flow rate. A major draw-back for this technology is that if the bladder is empty, the system has to be stopped and refilled before it can function again, a time consuming activity in a possibly critical event of a fire, also it is not possible to test a bladder tank system without consuming the concentrate.

This technology is in stark contrast with the simplicity of the FIREMIKS solution.

FIREMIKS proportioner – how it works

As water is pumped into the FIREMIKS, the power of the water flow turns a rotor that is connected to a volumetric foam concentrate pump. The foam concentrate pump pushes the foam concentrate using the water’s own power, and creates the water/foam solution. Because the foam pump is driven by the force of the volumetric water motor, the dosing rate automatically adjusts to the amount of water going into the proportioner. The more water that goes in, the faster the drive coupling rotates and the more concentrate is pumped through to mix with the water. And since the foam concentrate is stored in regular atmospheric containers, one can fill up or switch tank during operation, i.e. providing an increased safety margin should the fire extinguishing take longer than anticipated.

The FIREMIKS is available in different flow sizes, it can deal with 300 lpm up to 12,000 lpm with selectable dosing or a fixed dosing rate at 1, 2 or 3 % (other dosing rates available on request) with all types of concentrates – including alcohol resistant ones and wetting agents.

Fixed or mobile units are offered, as well as an offshore anti-corrosion version. The portable version, as well as the fixed version, can be used on the fire ground to multiple nozzles at the same time and at different heights and hose distances.

Other advantages of the system is the fact that it can be regularly tested without discharging any foam – with a dosing return valve, the concentrate can go straight back into the concentrate tank, so there is no need to store or destroy finished foam solution, as Per explained; ‘No foam solution needs to go to waste during any mandatory security tests, which is good both environmentally and economically.’

In spite of the fact that the FIREMIKS is yet to receive FM/UL or LPCB approval, it is steadily gaining market share, winning contracts in competition with more established brands: ‘We have sold over a few hundred units all over the world, since re-launching in 2010, from Asia and Latin America to South Africa, on the basis of the strength of our engineering and design, and against companies that have FM approved proportioners. We are also moving into the shipping market, where one major order has been 36 FIREMIKS in off-shore version with water motors in bronze to the Singapore Marine. These units are DNV/GL certified. This year we will continue with certifying our product line to comply even more with the standards required by the international industry.’