September 2020

situation in your Technical Boiler House Risk Assessment. You may find that you don’t physically have the space or access. Solid piping is preferred and flexi hoses are not the recommended installation option. Can you get fuel, treated water, condensate, electricity and blow down for the temporary installation, a lot to plan for, but better to be prepared, even if you never have to use this facility. Evolving technology Inspection and boiler house attendance requirements have changed to take into account evolving boiler house technology such as remote monitoring, which is not covered in previous documents. The latest guidance advises on a wide range of control options, and recommends that personnel receive adequate training to perform their jobs safely and competently. BG01 recommends that operators and managers achieve the national industry standards through either the Certified Industrial Boiler Operator (CertIBO) scheme for operators, or the Diploma in Boiler Plant Operation Management (DipBOM) for managers. Both qualifications are part of the Boiler Operation Accreditation Scheme (BOAS). It may not be relevant to your biomass plant if you don’t have gas on site but there is now the Industrial Gas Accreditation Scheme (I-GAS) that allows those working on gas outside the Gas Safety (Installation and Use) Regulations (GSIUR) to help prove competence. Lower manning levels Boiler houses have traditionally been fully attended, but with emerging technologies that provide greater automation, there is now provision for the plant to be visited once every 24 hours, and even less frequently – once every three days. If boiler owners are to feel confident of being able to cut down on the frequency of visits to this degree, they will need to have in place some very sophisticated automation. For example, high integrity self- checking probes must be in place to ensure that any feed water failure triggers a failsafe device in the boiler. The risk assessment will determine the minimum frequency of routine testing required. A high level of fire protection is clearly crucial, and alarms and shut-off for the fuel must be key considerations in the design and set-up of a boiler house. Equipment with a monitoring role or safety function, which acts in a predetermined manner to prevent a dangerous situation from occurring, is available to enhance the automation of the boiler house. For example, a ‘low water level’ alarm prevents boiler operation when the water level falls, but allows automatic restart and resumption of operation once the water level has risen to a safe level. A second low-level lock-out is fitted as a precautionary measure should water levels fall too low, and, if triggered, this requires manual intervention by a trained boiler operator before the boiler can be reinstated. Safety systems should be designed according to BS EN 12953 and BS EN 61508, but, where electrical equipment is involved, BS EN 50156 should be applied. Feedwater issues A major cause of boiler failure lies with the treatment of the feedwater that enters the system. If this is not strictly controlled and monitored, there is a risk of limescale build-up, to the point of failure. Safe and efficient operation depends on the boiler remaining within its safe parameters during operation. A feedwater specialist should be employed to regularly check the water treatment plant and test the quality of its resulting water before it enters the system. But your own staff need to understand what the chemistry is doing in your boilers; to ensure you stay on top of the water treatment regime they should receive suitable and sufficient training. If unattended and not checked, it will potentially lead to a massive expense. If this is done correctly it can save thousands of pounds, if it’s done badly it can cost you thousands of pounds. BG04 will help you with this and the Steam Boiler Water Treatment training (SBWT) course is now available to help in training your staff. While all combustion plant has an environmental impact, maintenance and operation of a boiler house according to best practice guidelines will help to support an energy efficient regime. This should include metering to monitor the boiler’s efficiency; correct water treatment to ensure that this efficiency is not compromised; combustion analysis and burner adjustment to reduce energy loss, and the introduction of improvement devices such as economisers, variable speed drives, and flue gas dampers. Many installations are required to have an Environmental Permit, and operating the boiler outside of the conditions that this permit scheme applies is illegal. Smaller plants still fall under regulatory environmental control; the Clean Air Act 1993 covers local issues such as smoke and dust from the plant. MCPD is now law for any combustion plant >1MWth input - <50MWth input, and you must measure and report the SOx, NOx, Dust/Particulates, and measure CO, for all new plants >1MW now and existing plants in a few years’ time. Correct understanding vital Using substantial volumes of energy, generated on site, is inherent in the proper functioning of many facilities. Yet without the correct understanding, interpretation, and implementation, of the law, the owner of the boiler stands to be liable for any failure. Accidents involving boilers have the potential to kill; as a result, the law is strict. The most senior person on site, the MD, CEO, Commanding Officer, etc. is ultimately responsible for the management of the boiler plant or consequences of an incident, even if they have never seen the boilers. They can of course delegate the responsibility to operate and manage the plant to a suitably trained and competent manager who must also have a suitably trained and competent operations team doing the day to day operations. The Combustion Engineering Association would encourage all owners, users and operators of boilers or burners to join the CEA, which in turn provides access to the knowledge available on all aspects of boiler house management and steam systems in general. For further information please email: info@cea.org.uk 30 | Plant & Works Engineering www.pwemag.co.uk September 2020 Energy, the Environment & Water Focus on: Boilers, Burners & Controls