OCR Text |
Show Use of Optical Sensors on Industrial Oxy-fuel Burners for Process Control W. Von Drasek, E. Duchateau, and L Philippe American Air Liquide, Countryside, IL 60525 1997 American Flame Research Committee International Symposium Chicago, Sept. 21-24, 1997 ABSTRACT With stricter environmental regulations, the need for manufacturers to optimize their combustion processes for emission reduction and higher fuel efficiency has become ever increasing. To achieve better optimization of the combustion process the need for improved and alternative methods for monitoring and controlling combustion parameters is required. Here we present a novel method for monitoring and controlling oxy-fiiel burners by strategic placement of optical sensors. The sensors are integrated into an industrial oxy-fuel burner capable of withstanding harsh environments. Radiation from the flame at selected wavelengths that cover the O H , C H , and C2 bands are collected from the burner and transported to a P C spectrometer by fiber optics. Using neural network models the signals from these species provide real-time measure of the stoichiometry and firing rate. The processed information can then be used in a control-loop for adjusting and optimizing combustion parameters. Results using the sensor on a commercial glass furnace will be presented. I. INTRODUCTION Stringent environmental regulations on allowable emissions, e.g., nitrogen oxides (NOx) and particulate matter (PM) have forced many industries to search for alternative combustion methodologies. One viable alternative that has proven to be cost effective is oxy-fiiel combustion, that consists of substitution of air with high purity oxygen (>90%). To date there have been numerous examples discussing the benefits of using oxy-fiiel combustion. One example of the successful use of oxy-fuel is seen in the glass melting industry, where typical results show savings in capital and operating costs, drastic reduction in NOx and PM, improved glass quality, fuel savings, and production increase due to enhanced heat transfer [1]. Despite these numerous advantages process optimization is still warranted to achieve the full benefits that oxy-fuel combustion offers. For example, minimum NOx emission can only be achieved when the excess oxygen in the stack is kept low, as shown in FIG. 1 below. l |