Any excess air that is supplied when controlling combustion in a heating furnace will absorb heat inside the furnace before exiting via the stack. In addition to resulting in heat loss, this can generate large volumes of nitrogen oxides and sulfur oxides, a source of air pollution. On the other hand, if insufficient air is supplied, complete combustion will not occur, resulting in energy loss, the emission of carbon monoxide and black smoke, and residual methane. Carbon monoxide and methane are flammable gases that can readily form an explosive mixture with air if allowed to accumulate inside a furnace.
As such, oil and gas, petrochemical, electric power, iron and steel, and ceramics plants need to monitor the concentrations of oxygen and carbon monoxide or methane inside furnaces in order to control and thereby ensure an efficient, environmentally-friendly, and safe combustion process. However, the use of digital devices in zones where combustible gases reach concentrations that result in the risk of an explosion is limited by regional laws and regulations as they have the potential to ignite such gases. To address this need, Yokogawa has developed this latest version of the TDLS8200 probe-type tunable diode laser (TDL) spectrometer.
The most significant feature of the TDLS8200 is its dual laser light sources and optics, which give it the ability to simultaneously measure oxygen plus either carbon monoxide or methane concentrations for combustion control. Its direct measurement system relies on the use of lasers, which are easier to maintain than conventional sampling systems and are more robust than catalyst-based sensors. This ensures stable, simultaneous, and lossless measurement. Also, by adopting a probe design with no sampling device, it is easy to install and replace.
The explosion-proof TDLS8200 that is being released for sale conforms to the IECEx explosion-proof standard of the International Electrotechnical Commission (IEC), the FM explosion-proof standards of the US and Canada, and the EU’s ATEX explosion-proof directives. Compliance with these regulations enables the device to be used in zones where combustible gases reach concentrations that result in the risk of an explosion. Going forward, Yokogawa will work toward acquiring certification for the explosion-proof standards of other regions and countries too.
