Spark Detection & Suppression Systems
INTRODUCTION
The subject of spark detection and suppression systems is fully covered in the RISCAuthority publication RC28 – Recommendations for spark detection and suppression systems on pneumatic conveying installations. All Consultants should be aware of its existence and the valuable guidance provided.
APPLICATION
Spark detection and suppression systems have been on the market for many years and have grown in number as manufacturing plants have become larger, more sophisticated and more valuable, both in terms of asset value and business dependency. Any process or manufacturing industry in which ducts, hoppers, filters, silos, dryers and other vessels contain finely divided combustible materials will have a potential application for a spark detection and suppression system. Typical examples include:
Textile Industry – brushing and raising machines
Food Industry – bakeries, spice milling, rice milling, cereal production
Rubber and Plastics – regrinding and granulating machines
Metalworking – flue gas filtration in foundries, metal polishing
Timber Panel Industry – presses, dryers, cyclones, screens and mills
Woodworking – dust and waste extraction systems
Printing Industry – dust and waste extraction systems
Recycling Industry – crushers and screens
GreCon Ltd are one of the principal spark detection and suppression firms in the UK offering an all-embracing service of site quotation surveys, design, installation and servicing.
Reference to their website https://www.fagus-grecon.com/en/fire-prevention/ will provide much valuable information. Other companies in this specialist field include Minimax Viking Group , Orthos Ltd, distributors of Firefly equipment www.orthos.uk.com. Most systems employ water mist as the extinguishing agent, although in some cases CO² or an alternative gaseous agent may be used. The main Firefly website www.firefly.se is an additional source of information.
It is important to recognize that spark detection and suppression systems are intended to be installed to complement and not to replace conventional protection methods such as screening and explosion relief.
Costs for the supply and installation of spark detection systems will vary considerably depending on the extent of the protection requirements. As a rough guide, the average cost for a single application system is circa £15,000.
Typical duct installed spark detector and suppression
STANDARDS AND APPROVALS
There are no recognised British or European Standards specifically covering spark detection and suppression systems, although FM, NFPA and VdS operate system approvals schemes.
Each of the GreCon, Minimax and Firefly systems has achieved approval to at least one of these schemes. A CEA approvals scheme was introduced some years ago, but this appears to have been little utilised.
SYSTEM MAINTENANCE
As with all fixed fire protection systems, maintenance and testing of the installation is essential and reference should be made to the guidance in Section 6 of RC28. In addition to routine maintenance “in house”, full inspection and maintenance the system(s) should be carried-out by the installer annually or more frequently as advised.
RISK IMPROVEMENTS
Requirements/Recommendations for spark detection and suppression systems are to be risk based in which due regard should be taken of the potential exposure (EML) in respect of MD & BI. As a general rule, these would normally come into play where exposures are in excess of £10m. Consideration for such protection below this figure may be necessary when dealing with a particularly hazardous risk and/or where there is adverse loss experience. Except for extreme situations, risk improvements for spark detection systems would normally be submitted as Recommendations.