Fire prevention is a prime concern in many applications where dust control and filtration are required. This includes wood processing, manufacturing, biomass, waste processing including SRF and RDF facilities, and other processes that create significant amounts of dust that need to be controlled for health and safety reasons, and for process control purposes. Many of these processes inherently contain the risk of producing sparks, embers or hot particles which can lead to a dust explosion or a fire. This can result from continuous operation of fast-running machinery, high operating pressures, and high process temperatures.
In the event of a fire or explosion there is a risk of injury and loss of life; damage to expensive machinery; damage to premises and storage facilities; production interruptions resulting in a loss of income and/or customers. These safety and economic risks can, however, be mitigated by employing field-proven automated fire prevention solutions with early detection and extinguishment of ignition sources before they are able to cause a fire or explosion. This helps to protect people, premises and enable interrupted process and production.
Fire Prevention Solutions
Various methods are available to detect fire, or the risk of fire. The simplest of these can be temperature measurement or flame detectors. The downside of some of these solutions is that they can alert too late, once a fire is already established or beginning to smoulder.
Infrared detectors can be used to provide the earliest detection of risk; the most sensitive will see as little as a single spark. GreCon recently launched the DLD 1/9 detector which provides optimal detection performance for all ignition sources in any environment, thanks to intelligent detection technology used to prevent false alarms. Hot particle detection in processes with temperatures up to 150 °C is possible, and sensitivity is adjustable for the perfect fit to the individual threat, allowing appropriate levels of safety plans and mitigatory actions to be automatically triggered.
In a dust control system, the most effective place to detect sparks or embers is when the material is pneumatically transported in a duct to a filter. Swift initiation of extinguishment is vital to implementing an appropriate fire prevention solution. Extinguishers are most effectively installed when considering the speed of material transport in relation to the reaction time following a detection event. In these instances, the sparks and/or hot particles are extinguished in milliseconds before they can proceed further through the process and cause a fire or explosion.
Locating spark detection and extinguishing systems
Consideration should be given to the location of fans within a dust control system. In a positive pressure system where the fan is located before the filter, detection and extinguishment should be located after the fan if there is a sufficient length of duct available. If there is not and the primary detection and extinguishment must be located before the fan, a secondary detection point should be located between the fan and the filter. This means that a control signal can be used to initiate a shut-down of the process or plant. This is because although any ignition sources originating in the process will have been dealt with, there is potential for a foreign object (e.g. a small piece of metal or stone) to be in the transport system. This foreign object is likely to cause a shower of sparks if it strikes the impellers of the fan; shutting down the system at this point can prevent “fanning” of the ignition source such that smouldering and burning accelerates and risks a filter fire.
With a track record spanning 28 years, GreCon Limited has provided engineered fire protection solutions to businesses across the UK & Ireland. The company offers turnkey solutions and a comprehensive in-house service, delivered by a UK based network of engineers with a reputation for highly skilled, high-quality work. Following a recent installation, Paul Brammer, Production Manager with Panelco Ltd, said “May I just thank GreCon for the fantastic installation and professionalism while onsite. The two fitters that attended site are a credit to GreCon”. GreCon Limited has the knowledge, instrumentation, and equipment to effectively specify and install a system to prevent a fire before it has an opportunity to start.
GreCon Limited
0191 4147200
sales@grecon.co.uk
www.grecon.co.uk
