Industrial sites inevitably turn to foam-dosing systems to suppress fires, but it is important to carefully consider the competing options to ensure the best possible cost, safety and environmental outcomes.
In the battle to contain fires on industrial sites around the world, foam has long been the go-to suppressant. For good reason.
Unlike other extinguishing agents such as water, a stable aqueous foam can quickly put out a flammable or combustible liquid fire thanks to the combined effects of cooling, separating the ignition source from the surface of the blaze, suppressing vapours and smothering the fire. Water, by contrast, is much heavier than foam and can sink when applied to the fuel surface, resulting in minimal effect in terms of extinguishment or vapour suppression.
However, not all foam-suppressant solutions are created equal, with products and their efficacy varying dramatically.
In general terms, industrial site operators have to make a choice between various types of dosing models. On one side are traditional bladder tanks, balance pressure proportioners and in-line inductors that have been used for many years, and on the other side are newer solutions such as water motor-driven pump systems that are increasingly seen as the industry standard in fire-fighting installations. The popular Firemiks range is an example of the latter.
Following is a comparison of the two broad options:
1. In the industrial sector, bladder tanks have come under criticism because they are often complicated to set up and maintain. Likewise, balance pressure proportioners and in-line inductors can be difficult to commission. Due to its relatively low weight and compact design, installation of a Firemiks product is comparatively easy.
2. Bladder tanks are a time-limited system. So when the foam bladder is empty, the system must be stopped for refilling, whereas Firemiks offers an uninterrupted system as long as water and foam concentrate are available. If the foam tank is empty with a Firemiks, additional foam concentrate can be supplied from a separate source fairly quickly via pales, drums, IBC’s etc without interrupting the water flow and fire-fighting.
3. With bladder tanks, the rubber bag inside the pressure tank may deteriorate over time, but no rubber bag is required with Firemiks. With balance pressure proportioners, a separate ratio foam controller is needed to create the right pressure balance.
4. Significantly, it is not generally possible to test proportioners and inductors without consuming foam concentrate, whereas with Firemiks a foam return valve can enable fast testing of the system without consuming foam concentrate. This can result in significate cost savings with both replacing the used concentrate and also the disposal costs for the generated solution.
The market consensus is that Firemiks offers a greener alternative to bladder tanks, balance pressure proportioners and inline inductors, too, with the former using an efficient proportioning system for dispending foam that makes it economically and environmentally viable. As they are driven by the water flow which goes through the motor, they also do not require an external energy source. The system works with virtually all types of foaming agents, and there is no need for complicated pressure balancing or calibration.
On the safety front, the Firemiks also performs well. Since the foam concentrate is stored in regular atmospheric containers, the firefighter can fill up or switch tanks during operation, thus providing an increased safety margin should the fire extinguishing take longer than anticipated.
The upshot of all these advantages is that the Firemiks system gives industrial sites the best possible chance to extinguish potentially devastating fires, while at the same time being more cost-effective and environmentally friendly than other options.
It is a compelling list of benefits – and one that managers of industrial sites need to consider carefully when considering their fire-fighting systems.
Delta Fire Australasia specialises in the design, installation and servicing of fire-suppression systems on petrochemical and other industrial sites. Visit www.deltafire.com.au for more details.