Flame detectors are working together with a watermist system to protect over 700 metres of conveyors carrying highly flammable biomass

As part of the conversion of Ironbridge power station in Shropshire from coal to biomass, E.ON Energy has constructed a biomass handling depot at Gladstone Docks in Liverpool to allow for the delivery and transfer of biomass, in the form of wood pellets, from anywhere in the world to Ironbridge via train.

The depot consists of three conveyors totalling over 700m in length, which move the biomass direct from either ship to train or from ship to a large storage building. The highly flammable nature of the biomass required the company to install an extensive fire detection and suppression system on all three of the main conveyors.

To achieve the required fire safety solution, the company chose a system based on FFE’s Talentum flame detectors and a high-pressure watermist system from Hydramist. The complete system was designed and installed by FFE contractor, Fireworks.

The Talentum optical flame detectors utilise infra-red (IR) sensing technology which allows them to very quickly detect flames – within seconds – irrespective of any dust, steam or smoke that may also present. With the addition of an ultraviolet sensor the detector can also become immune to false signals such as sunlight.

Each conveyor was divided up into fire zones, with each zone having a dedicated flame detector, zone valve, fire control panel and set of water pipes and spray nozzles. The flame detectors and nozzles were installed inside the conveyor covers to provide optimum protection of the biomass. The watermist system operates from a central high pressure pump set with 100% redundancy. In the event of a fire the area at risk is contained within a 30m section.

The system was then linked to a site-wide addressable fire panel which allows further automatic controls to be programmed, ensuring the desired number of zones will automatically operate when required and that the conveyors will stop as soon as the fire system operates.

Fireworks trained E.ON staff to operate the system and carry out fault-finding and remedial actions if required. The entire system requires minimal maintenance and is on constant standby 24 hours a day when the biomass handling depot is in operation.