Waste to Energy is part of the Green Energy Mix, it reduces greenhouse gases and plays an important part in the reduction of methane from landfills, not just offsetting emissions from fossil fuel production but also recovering ferrous metals for recycling. However, it is also an industry that needs to build in health and safety at all levels. Whilst the initial raw materials are not viewed as hazardous waste, the dynamics to convert this landfill to energy needs to measure and monitor high levels of pressure and temperature during the entire process. The incineration of this waste is used to raise steam in water tube boilers, which is utilised to turn turbines, creating energy. Knowing the balance of water and steam contained within the boiler is essential for the safe and efficient running of the entire facility.
As process instrumentation specialists, Delta Mobrey has years of experience in monitoring the levels of steam and water so that boilers operate safely. Hydrastep, has been designed specifically to monitor boiler levels, irrespective of industry, in the simplest and most reliable manner making it a great option for all Waste to Energy organisations looking to maximise the smooth operation of their facilities, with the confidence of knowing their water tube boilers are protected from low water levels and their turbines protected from water run over.
The Combustion Engineering Association, CEA, asked Delta Mobrey to contribute to their most recent guidance document, BG11, earlier this year because of the reputation which Hydrastep has earnt over the years. Whist BG11 gives guidance on the design, operation and maintenance practices relevant to the UK, the practices highlighted are of benefit globally as their basic premise is safety and efficient boiler operation. BG11 includes guidance on Control Systems and Instrumentation to ensure the safe and efficient operation of the boiler systems. The guide explains that maintaining the correct boiler drum level is critical: if the water level is too low, there is a risk of damage to the boiler drum and tubes and of overheating. If the level is too high, water can reach and damage the superheaters, or eventually the turbines, causing catastrophic damage. BG11 states “There are many technologies available to measure and control steam drum levels and triple redundancy whilst mixing technologies is becoming common place.” The guide explains the need for a visual indication of the drum level and that this is a requirement of both BS EN 12952 and the ASME Boiler and Pressure Vessel code. Traditionally sight glasses were used, but these are difficult to read and often require regular maintenance. BG11 cites Hydrastep as giving a clear display, both locally at the drum and in the control room and is the preferred solution for steam drum level indication. (BG11 pg 26). [RJH]
Hydrastep was originally developed in conjunction with the UK’s CEGB. The use of conductivity probes, positioned along a vertical water column, gives a highly reliable method to differentiate between steam and water. The level display can be repeated in the control room and is immediately visible to operators without having to look at monitors.
Alarms or trips can be assigned to chosen levels. The dual redundant design means that even with an internal fault, the Hydrastep will continue to give a drum level indication. It is no surprise that BG11 refers to Hydrastep as having exceptional reliability (BG11 pg26).
Delta Mobrey’s Hydrastep is already being used at a number of Waste to Energy plants within the UK and further afield within Europe. Hydrastep is becoming the choice of plant operators to ensure the safety of the plant and personnel.
About Delta Mobrey
For more than 100 years, Delta Mobrey Limited has been a world-leading specialist in the design and manufacture of quality process instrumentation for the measurement and control of fluids and gases in all industrial plant and equipment.
Trusted quality – proven value: quality and reliability have always formed the cornerstone of our success, recognised by industry with international approvals covering every aspect of our manufacturing and product portfolio, together with certifications spanning all areas of hazardous and regulated environments.
Global team – local support: as a global organisation, Delta Mobrey is totally committed to delivering the best possible customer service and technical support, ensuring a lifetime value of ownership, together with a flexible and responsive approach to meet our customers’ individual demands.