Oxygen Analyser at crematoria in Australia

A key operator of cremators in Australia has installed Michell Oxygen Analysers at their sites around the country, helping to reduce their consumption of natural gas by 40%.

With its fast reaction to changes in conditions in the chamber, the XZR500 enables the process to be run as efficiently as possible, with the minimum of emissions. In Australia no smoke is allowed to issue from a crematorium, and the reduction in emissions makes it easier for the company to comply with this legislation. Although all the exhaust from the cremation chambers is filtered before being released into the atmosphere, minimal emissions eases this process once again saving costs.

There are two reasons for using oxygen analyzers to control oxygen in cremators: the first is to reduce fuel consumption and the second is to keep emissions to a minimum. Cremators often operate up to 15 hours a day, reaching temperatures of up to 1150°C, so fuel efficiency is a crucial part of keeping costs down. Australia’s Carbon Tax is an added tax on fuel use to further encourage businesses to be fuel efficient for the sake of the environment and to conserve natural resources. The 40% reduction in fuel used by the operator means that the cost of cremations can be kept to affordable levels.

The Michell XZR500 analyzers ensure that the level of oxygen in the chamber is kept at the optimum level for combustion. Too little oxygen means that more fuel is needed, while too much oxygen results in a fast burn, but a high level of emissions such as mono-nitrogen oxides (NOx), sulphur oxides (SOx), carbon dioxide (CO2) and carbon monoxide (CO).

The atmosphere with a cremation chamber is highly aggressive so a sensor that is capable of withstanding not only high temperatures but also harsh conditions is important. At the start of the cremation process, there is a lot of moisture present in the chamber. Many chemicals are also released including from clothing, replacement joints and mercury fillings. The Zirconia Metallic Sealed Reference Senor (MSRS) in the XZR500 is designed to withstand these conditions for long periods of time. The semi-insitu design allows non-conditioned (or representative) sampling with minimal installation. The Pitot effect in the sampling probe – where the gas is drawn along the probe as through a chimney – negates the need for aspirator air which is a further saving. The Iconel probe is particularly suitable for the aggressive environment. The sensor has a built-in porous ceramic filter to further protect and prolong the life of the sample cell.

• Michell Instruments is marketed in Ireland through Instrument Technology Ltd.