A power company is using the Digihelic differential pressure controller at one of its generating stations — a coal burning power plant. Due to environmental compliance issues many power companies are being asked to control NOx emissions. NOx is a combustion-generated gas that consists of nitrogen oxide (NO) and nitrogen dioxide (NO2). One control method currently used when combusting solid fuels, such as coal, to reduce NOx emissions is called SCR (selective catalytic reduction). This is a post-combustion process that can reduce emissions by 50-60 percent. The SCR system being installed uses ammonia to perform the NOx reduction. The power plant’s method of ammonia injection utilizes an ammonia injection grid with 33 individual valves. The ammonia is injected into an air stream moving between 350-500 SCFM. An averaging Pitot tube is used for flow measurement and the Digihelic computes the SCFM from the averaging Pitot’s differential pressure signal. The Digihelic computes airflow output, via its RS-485 communications, which is then transmitted wirelessly to a computer lab running a software package that adjusts each of the 33 valves for balance control. Endress+Hauser: Proline Promass F 10-Inch Sensor Coriolis system for natural gas fenceline measurement
The Promass 83F 10-inch Coriolis mass flowmeter was the solution of choice for a major global chemical company conducting a fenceline measurement for natural gas. This measurement used to be done with an orifice run over multiple years. Promass 83F 10-inch caught the company’s attention though, as Coriolis technology was already successfully used in other applications, but was so far not available for the large pipe sizes and higher flowrates required to match the needs of this application. The Promass 83F 10-inch not only met the pipe size and flowrate requirements of the application, but also provided a specified accuracy of +/-0.35 percent of reading for natural gas and an increased turndown by more than a factor of 10 over the previous system, calculating to a monthly savings of several thousand dollars for the chemical company. Kayden: Classic Flow/Level/Temperature Switch Natural gas flare stack or rupture disc early warning
Since two-thirds of the power consumed by wastewater treatment plants is devoted to the aeration process, the Opti-Con controller aims to provide complete control over energy usage by the aeration equipment while managing the biological treatment process. The philosophy behind the creation of the Opti-Con controller system is to take advantage of the varying loads and flows during a day, often referred to as the diurnal curve. Essentially, this curve depicts the demand for biological control over time. First-generation systems waste large portions of power due to being set at a specific level. This is often an operation average that ensures the permitted level of effluent is met. The Opti-Con, on the other hand, constantly monitors the real-time characteristics of these aeration basins to meet the influent demand. By following the diurnal curve’s ebbs and flows, the process power is utilized only when required, turning down aerators to take full advantage of power saving potential. Rosemount: 3051S Ultra for Flow Transmitter Providing improved accuracy and wider flow turndown