In Spring 2019, Tarmac partnered with Hamilton Waste and Recycling to improve the sustainability of its operations at its cement plant in Dunbar, Scotland. This involved the production of solid recovered fuel (SRF) as an alternative energy source, which would decrease reliance on fossil fuels and the plant’s overall carbon footprint.
The fuel is now produced at Hamilton Waste’s site from non-recyclable waste material, using a Lindner shredder. The SRF is then transported and stored at Tarmac’s Dunbar plant where it fuels the plant’s operations.
‘The production of SRF carries a high fire risk which, if not managed properly, can impact on the safety of people, machinery and other resources,’ says James Mountain, director, Fire Shield Systems. ‘The safe storage of any flammable materials also requires careful planning and consideration.
‘Both Tarmac and Hamilton wanted to ensure their sites remained as safe as possible and, as a result, we were asked to assess all of the relevant fire risks and design two, bespoke, automatic systems which would protect both the process and storage areas.’
The site surveying process
‘The first step is to review a detailed site map of the proposed site. This is used to create an auto-CAD version of the site map,’ explains James. ‘A visit to the site is then carried out, to take measurements and closely take a look at machinery and processes, whilst also confirming the locations of water and power sources.
‘The next step is to make the hydraulic calculations for the specific site, such as pipe runs, lengths and locations.
‘The final step is to design the solution. Using all of the information collected, a bespoke fire protection solution is designed for the site, taking into consideration all of the unique requirements.’
‘Fire Shield Systems surveyed both our production site and Tarmac’s storage site to develop a cost-effective solution which was third-party accredited and approved by both our insurers and the Environment Agency,’ says David Hamilton, director, Hamilton Waste.
Working in line with Environment Agency and insurers
‘The Environment Agency sets out specific requirements for fire protection plans so you need to ensure you work with a partner which understands this. By placing focus on the requirements set out by the EA, along with the specific needs of a site, a tailored solution that meets the requirements of an FPP is created for each site,’ says James.
‘Communication is made directly with the insurers to find out the details of the risk assessments that they carry out. Often, individual insurers have their own standards and preferred solutions, so for each project, the solutions are tailored to meet the specific requirements.’
‘For the production site at Hamilton Waste, a fire cannon and organic class A wetting agent, operated by a multi-zonal LPCB accredited flame-detection system was installed,’ says James. ‘This gave us targeted suppression, offering fast protection and minimal clean up.’
Using infra-red sensing technology the system can detect flames from all fuel types, from hydrocarbon fires with 4.3μm emissions, through to invisible fires such as hydrogen through such elements as dust, steam and smoke. It is also immune to the effects of wind or draughts of air. Once a fire is detected in the specific area or ‘zone’ the cannon is then directed to the corresponding position via the Cannon PLC.
‘The Dafo system – a standalone SPCR approved fire suppression system – was also installed for the protection of the machinery-drive enclosure. This system offers robust and reliable linear heat detection, using mains power and a stored-nitrogen cartridge to operate the foam hybrid wetting agent to provide maximum protection.’
‘For the SRF storage at Tarmac’s Dunbar plant, a DFL type-tested water-spray system was selected for its efficient water usage and subsequent reduction of contaminated run offs,’ says James.
‘The water-spray system operates with fast-acting, IR3 flame detection which means, in the event of activation, any operations downtime is minimised.’
‘We’ve used other systems in the past, but this situation required a more specialised and technical solution,’ explains David. ‘Fire Shield’s experience in installing similar systems gave us confidence in the team’s expertise.
‘From start to finish, Fire Shield has been very professional.
‘We couldn’t fault the service. They’ve delivered the best-in-class and most cost-effective solution to a very high standard. We would absolutely recommend Fire Shield Systems to other businesses looking to improve the fire safety of their operations.
‘We couldn’t be happier with the results.’
For more information, go to www.fireshieldsystemsltd.co.uk