Nitrogen oxides (NOx) are an unwelcome group of gases that are the byproduct of combustion. In industries where combustion is used for heat or power, high oxygen levels in exhaust flues or stacks can indicate increased NOx levels as well as poor fuel combustion.
To minimize NOx in industrial settings SST Sensing has introduced the GAP Gas Analysis Probe, an all-in-one oxygen sensor that can be used to monitor oxygen levels in flue gases.
How is NOx Produced?
NOx is the name for a group of gases including Nitric oxide (NO) and nitrogen dioxide (N20). Measured in parts-per-million, NOx gases are produced from the reaction of nitrogen and oxygen molecules in the air during high-temperature combustion. In the atmosphere, NOx gases contribute to "smog" and are considered greenhouse gases.
Results of Low Combustion Efficiency
Inefficient combustion results in increased NOx levels which are not only bad for the environment, but increase fuel costs.
According to SST
"Efficient control of the combustion process plays an important role in reducing NOx output, reducing wasted fuel costs, increased lifetime of the flue or stack, increased process efficiency and reduction in thermal loss. It is estimated that every 1 % reduction in excess oxygen translates to a reduction of 20% NOx output and a further 1% reduction in fuel costs (source: North American Manufacturing Handbook)".
Improving Combustion Efficiency
To lower NOx levels, the amount of oxygen gas remaining in the flue or stack after combustion needs to be accurately measured. This data can then be used as feedback to more precisely control the fuel used in the combustion process.
Industrial Oxygen Sensors and Controllers
Oxygen industrial sensors and fixed industrial oxygen controllers are both essential tools in monitoring and maintaining safe oxygen levels in various industrial environments.
Oxygen industrial sensors are typically portable devices designed to measure and report oxygen concentrations in real-time, providing immediate feedback and ensuring that levels remain within safe limits. These sensors are often used in dynamic settings where monitoring needs to be flexible and mobile, such as in confined spaces, temporary work areas, or during maintenance operations. They offer the advantage of quick deployment and ease of use, making them ideal for tasks that require frequent relocation and immediate response to potential oxygen deficiencies or excesses.
Fixed industrial oxygen controllers, like the Fixed Oxygen Gas Detector, are permanently installed systems designed for continuous monitoring and control of oxygen levels in a specific location.
These controllers are integrated into the facility’s infrastructure, providing constant surveillance and automated regulation of oxygen concentrations. They are particularly beneficial in environments where maintaining consistent oxygen levels is critical, such as in manufacturing plants, laboratories, and storage areas for flammable or hazardous materials.
Fixed controllers also commonly include advanced features like audible/visual alarms, data logging capabilities, and integration with other safety or BMS, ensuring comprehensive protection and compliance with safety standards. The choice between portable sensors and fixed controllers depends on the specific requirements of the industrial application, including the need for mobility, the scale of monitoring, and the level of automation desired.
Gas Analysis Probe Oxygen Analyzer
SST's newest design is the GAP - Gas Analysis Probe, an all-in-one solution for combustion efficiency control in flue gas temperatures up to 700°C (1,292°F). The sensor is an in-situ stainless steel probe that draws the gases across the sensor via the pitot effect. This method allows the sensor to be contained outside of the stack/vent wall which allows maintenance to be carried out without removal of the probe.
Features
- The sensor is designed to need only one span point calibration which can be made in fresh air (20.7% O2), or the external calibration port can also be used to inject instrument or calibration air to the sensor should be specific calibration points be requested.
- The sensor head contains the electronics, cable gland connection, user replaceable sensor module. Removal of the head takes seconds and this also exposes the twin tubes which can easily be cleaned of any dust and soot.
- Industry-standard 4-20mA outputs for oxygen concentration and pressure provide linear signals for process control.
- Two relay outputs with one for control and one for fault conditions provides reliable set point control.
- RS485 Modbus RTU provides remote communication and control of relay outputs as well as multi drop addressing and system configuration.
- The front panel display is IP65 rated and has soft touch push buttons allowing system configuration, manual relay control and commissioning tests. The display provides a two line readout of O2%, ppO2, temperature, pressure, relay set points and states, plus any fault codes.
The GAP Gas Analysis Probe is an ideal solution for minimizing costs via accurate measurements, long service life, low maintenance, and simple operation. Click here for more information or to purchase.