Emissions Monitoring on Cremators
Over the past 20 years Orbital has worked closely with a number of cremator system manufactures and also directly with the crematoria themselves to develop emissions monitoring systems on the high temperature secondary combustion chamber in cremation systems. The design and operating conditions of crematoria is regulated by DEFRA under the guidance note PGN 5/2 (04), this document specifies that the temperature in the second combustion chamber should exceed 850 degC to meet combustion criteria.
Extractive gas monitoring on cremators requires that gas is drawn from the combustion chamber whilst the chamber is at temperature, however this presents potential problems in that the sample probe itself must be able to withstand temperatures cycling in excess of 850 degC in a corrosive chlorinated atmosphere. In addition, most cremators in the UK are designed to be fitted into existing buildings and this often restricts where the probe can be fixed into the chamber, ease of maintenance is therefore an important consideration.
By working closely with system manufacturers, Orbital have over the years developed a solution to high temperature sampling in this application. Our ‘Stackmaster’ sampling system has a sample probe manufactured from Kanthal alloy, which has both an extremely high melting point of 1300 degC and is chemically resistant to the corrosive gases present in a cremation system. In addition, the probe design is such that the integrated ceramic particulate filter can be easily accessed for maintenance even in confined spaces.
Guidance note PGN 5/2 (04) also specifies that, amongst others, carbon monoxide and oxygen emissions be monitored. Again, working closely with cremator manufacturers Orbital have designed standardised emissions monitoring systems for CO and O2 specifically for use in cremator systems, the system supplied differs depending on the layout of the cremator building.
Clearly the operating cost of a cremator depends amongst other parameters on the amount of fuel fed into the burners, by monitoring the oxygen levels and feeding the oxygen level signal back into the burner control system the fuel to air ratio can be optimised greatly improving the efficiency of the system.
With the exception of routine maintenance which can be carried out by our own service team, our emissions monitoring systems are fully self contained and do not require any day to day user operation.
We estimate that Orbital have emissions monitoring systems on over half of the 250 or so cremators in the UK. We have designed, installed and serviced systems in crematoria for over 20 years.