Raille Limited products

Dust extraction systems are used in many industries to remove waste material from the process machinery. Likewise, bulk handling conveyors are used to transport raw materials to each stage of the process. Both are also effective routes for sparks, embers and burning material to be carried to dust extraction filters, cyclones and storage silos where conditions may be ideal to ignite a fire or explosion.

As the most effective means of preventing fires in dust extraction filters, cyclones and silos, spark detection systems are used throughout industries such as woodworking, recycling, biomass and pellet production. Sensitive detectors combined with high speed extinguishing units prevent ignition sources passing through the dust extraction ducts and so prevent fires starting downstream; the concept is straightforward and well proven.

Raille’s current series of control panels provide central monitoring, testing and control of all spark, ember, heat and flame detectors, activating extinguishing reactions and other responses according to adjustable risk thresholds.  Details of detection / extinguishing events are displayed in clear, programmable text and saved in the system’s memory, as are fault reports and the system configuration.  Reports can be viewed on the panel’s LCD screen or downloaded to a laptop and viewed or printed out.

Manufactured with a stainless steel casing, Raille spark detectors are robust and reliable, even in harsh industrial environments.  The detector lens is installed almost flush with the inside wall of the extraction duct or drop chute, so it does not interfere with material flow.  ATEX approved for use in zone 20 explosive atmospheres. The FSK3 model spark detector (direct mount model) reacts to both infra red and visible light, picking up ignition sources such as sparks, embers, hot particles and burning material.  This type of detector is plugged directly into the wall of the extraction duct via the mounting adapter and so can only be used in low temperature (< 60°C) applications.  It has high sensitivity in order to react to small sparks moving at high speed, making it suitable for use in dust extraction ducts to protect against filter fires.

The FSL3 model spark detector (remote mount model) has the same response as the FSK3 and so is equally sensitive reacting to ignition sources.  It views the detection point via 3 glass fibre optics and so can be used in high temperature and high vibration applications. The FST3 model ember detector reacts to light further into the infra red spectrum than spark detectors and so is not effected by variations visible light.  Ember detectors are less sensitive to small ignition sources than spark detectors and are generally used to monitor open conveyors and drop chutes where variations in daylight cannot be avoided.

Spark detection systems typically use water curtain extinguishers to prevent the spread of ignition sources through dust extraction ducts and bulk handling conveyors.  The extinguishers generate a dense curtain of water spray across the extraction duct when a spark is detected and are positioned so that the curtain of water will be at full spread and density by the time the ignition source reaches it.  The water curtain creates a barrier to prevent the ignition sources passing that point, but only sprays for a few seconds when sparks are detected so can be used in most materials and processes.