As printed in the February 2014 issue of Waste Advantage Magazine.
When it comes to preventing fires on the heavy equipment at landfills, the first line of defense will always be keeping machines clean and well maintained. Using compressed air to clear out the radiator and other areas that tend to gather debris is a common way to do this, and doing it frequently is the easiest way to stay ahead of a problem. This is always time well spent. After all, failure to follow this best practice can result in a build up of flammable fluids and materials, which sets the stage for a fire.
On top of keeping the machine clean, a good fire prevention technique is installing fire wraps on turbochargers and exhaust manifolds. The difference between the surface temperatures on treated and untreated surfaces is significant and can mean the difference between a fire starting upon contact or not. Newer models often will have this material in place, but there is a good chance that it has not been retrofitted onto older equipment.
But let’s be realistic, in an environment where day in and day out literally tons of potential fuel meets very hot surfaces, the occasional fire is unavoidable, which is why automatic waste fire suppression systems are so critical.
Fire Suppression Systems for Waste Industry
A waste fire suppression system is an after-market safety accessory that is attached directly to the machine it is protecting. It is made up of tanks holding the fire-fighting agent (some canisters also hold nitrogen to power a discharge, other “side-cartridge operated” set ups keep the propellant in a separate bottle); a series of fire detection sensors; and a network of distribution tubing and nozzles. The systems can be activated either automatically when a fire triggers the actuation mechanism, or manually by an operator. The size of the system is determined by a “fire risk assessment” which evaluates how much agent would be needed to combat a fire given a number of factors, including the size of the machine’s engine, the volume of hydraulic fluids, the presence of other fuel sources, and other sources of intense heat such as turbochargers. The type of agent used to suppress a fire (dry chemical, liquid-only or dual agent) varies according to circumstances as well.
Choosing the Right Type of Fire Suppression System
The first consideration when choosing a fire suppression system type is the machine’s environment. For the landfill setting, dual agent systems are often recommended to take advantage of the strengths of each agent: the fast knockdown of a dry chemical agent and the cooling properties and extended discharge of a liquid agent. In enclosed areas, such as engine and transmission compartments, a dry chemical agent is an excellent option because it floods the space and smothers flames. When it comes to hot surfaces, such as turbochargers and exhaust manifolds, the targeted approach of a liquid agent is well suited for fire suppression, plus it has the added benefit of reducing their temperatures dramatically, which lowers the risk of reignition.
This combination approach will become even more appropriate as TIER 4 engines become more common on site. This is because these machines run hotter and are more likely to suffer from a reflash if a hydraulic hose has ruptured. At the end of the day, knowing when and where to use each type of protection is crucial, which is why systems should be installed and regularly serviced by heavy equipment fire suppression experts.
Proper Suppression Requires Proper Installation
In many ways, a waste fire suppression system’s effectiveness begins on Day 1 with proper installation. The highest risk components need particularly close attention since they are the most common starting points for fire. The most important of the areas to be addressed are the starter, the alternator, turbochargers and exhaust manifolds. Another area of major concern is the belly pan. This area is notorious for debris accumulation and needs to be protected, but a nozzle that is obstructed cannot effectively do its job of distributing the fire fighting agent. For this reason it is important that all nozzles protecting this area be installed above the debris line.
Proper System Maintenance is Everyone’s Job
Proper maintenance of the suppression system begins with monitoring it, and there is no substitute for an operator understanding the way a system works and taking an active role in the effort. A pre-shift inspection of the key components takes moments and provides the best defense against any potential operational issues. This is a wise process to have in place because there is no way of knowing when equipment damage might occur when working under such demanding conditions.
The condition of fire suppression system components should also be checked when machines are in for regular service. It is important to evaluate wear points if hydraulic hose is being used for the distribution network, especially on older machines since their rubber will begin to break down. Any worn material should be replaced as needed, as should any missing blow-off nozzle caps. If using a manifold type system with stainless steel tubing, then mechanics should be sure the compression fittings are tight and that the nozzles are properly aimed once reattached after service.
And finally, having regular service calls by a licensed and trained technician is the optimum way to ensure that your fire suppression system continues to protect your operators, your vehicles and your landfill.