Spark detection systems are designed to detect hot particles, embers, sparks or flame that might become the ignition source for a fire or explosion. By preventing sparks, embers and hot particles from reaching dust rich downstream process equipment such as dust collectors, bins and silos, both fire and explosion risks can be managed.
How does it work?
The most advanced spark detection systems, like BS&B’s SparkEx, use infra-red detectors, to recognise the radiated light emitted from sparks or glowing embers. The greatest sensitivity occurs when these sensors are employed in a dark area such as closed ductwork, although optional daylight detectors are also available for use on open conveyor belts and for applications where light is likely to be visible. Upon detection the system provides several options to manage the ignition risk:
- Water nozzles are activated which spray water downstream extinguishing hot particles;
- There is an option to activate an automated shut-down of the entire process to end the feed of combustible material along ductwork or conveyors;
- Alternatively, the spark detection unit can activate other devices’ shut-off valves along the materials handling feed;
- The System is able to operate in a continuous automatic detection mode.
The detectors and control unit are ATEX certified for use in dusty working environments. This means, there are no expensive costs for additional wiring to run from detectors to remote mounted control units. Furthermore, plant personnel have direct access to the status of the equipment; in the event that an alarm is triggered, the operator can see immediately which process is at risk. A web-based monitoring system, which allows plant managers to receive system alarms and faults to their smart phones, as well as monitoring the systems live on the internet, is also available.
Where would you use it?
Spark detection as a means of explosion protection is effective across a variety of industries: wood processing and pelletising, wood panel production, textile production, food processing and chemical processing. Spark detection would quench the initial threat of a fire – from the point of ignition and prevent development of a deflagration. It would be a solution in the following applications:
In the wood handling industries, the risk of sparks from machines operating at high speed, coupled with friction and high temperatures, are perfect incubators for hot particle creation. If they travel downstream to dust-rich areas of process equipment, then the risk of fire or explosion becomes certain.
The same danger exists in the food industry with the fine grinding and milling of foodstuffs such as coffee, sugar, cocoa where their finely ground particles, when put under pressure/increased friction, increase the risk of combustion.
In the chemical industry the risk of explosion is very high throughout the entire process. Many chemical products have a high risk of flammability and are susceptible to any high friction or dryer processes where they may become overheated and pose a fire hazard.
How advanced it is it?
Advanced systems should have full certification to meet safety requirements as set out in DSEAR 2002 and ATEX 95. For example, the BS&B spark detectors and control unit are ATEX certified.
There are no expensive costs for additional wiring to run from detectors to remote mounted control units, and plant personnel have direct access to the status of the equipment. In the event of an alarm status, the operator can see immediately which process is at risk. A web-based monitoring system, which allows plant managers to receive system alarms and faults to their smart phones, as well as monitoring the systems live on the internet, is also available.
Is it safer than other methods of explosion protection?
The key performance benefit of using spark detection is that it interrupts the ignition process right at the start. Therefore, a fire or explosion isn’t given a chance to develop.
Spark detection may be used in tandem with other preventative methods such as suppression or isolation, depending on the risk assessment requirements of the facility in question. However, it is the first point of protection that extinguishes the originating spark.
How does it enhance solids and bulk handling and production?
Spark detection systems should be considered as one of the most efficient means of explosion protection. It should be an integrated part of a factory’s fire protection because of its expedient response at the start of the incendiary process. In high explosion risk processes, if sparks and heated materials go undetected, any ensuing explosions caused by their unrestricted progress, can halt production, destroy a facility and take lives.