Combustibles monitoring

In our tests, the furnace was occasionally deficient of oxygen. When oxygen level went to zero, a significant amount of CO was produced as well as visible and sooty smoke. These are indications of incomplete combustion. The only product of incomplete combustion monitored was CO. Incomplete combustion products other than CO were not accounted for. 

Sufficiently cheap UV photodiodes are available but they are not visible-blind. Filters have to be used, but they raise the costs. Sufficiently selective photodiodes are also available but they are too expensive, mainly due to their only recently established technology. The sensor costs have been a limiting factor in two application fields of UV sensors, namely water disinfection and combustion monitoring, on the industrial as well as on the household scale. 

Mihalcea, R. M., D. S. Baer, and R. K. Hanson. 1997. Diode-laser absorption sensor system for combustion monitoring and control applications. 33rd Joint Propulsion Conference Proceedings. NY AIAA. AIAA Paper No. 97-3356. 

The application of semiconductor gas sensors (mainly the Sn02 sensor) is ever expanding into various fields, domestic and industrial, as shown in Figure 3. Examples are the CO selective sensor and combustion monitor sensor, which are applicable to micro wave ovens or ventilation fans, kerosene or gas stoves, hot water supply systems, and so on. 

For domestic use, more useful humidity sensors, CO sensors and combustion monitoring sensors will be developed with their increased integration into safety systems for homes and offices. 

Flame ionization detectors (FIDs) and photoionization detectors (PIDs) can be used for the detection of hydrocarbons. Both detectors have been utilized for combustibles monitoring in portable and fixed installation designs. The FID actually burns the sample in an H2 flame. A charged electrical field is positioned across the flame, and utilizing the ions in the flame can conduct a current. When most combustible materials are introduced into the flame, they produce ions in their combustion products, and these are detected by the increased flow of current across the electric field (flame). 

A widely used technique is IR monitoring, which is utilized for both point and area (open-path) measurement applications but cannot detect H2. The previously discussed detectors were point sensors. To monitor a large area, one would have to locate many monitors (points). In contrast, open-path IR combustibles monitors project their beams in a path that is typically 10-200 m in length and monitor all of the combustibles in that path. 

Combustion and system operating controls to include programming, combustion monitoring and operating rate regulation. 

J. Schalwig, G. Muller, M. Eickhoff, O. Ambacher, and M. Stutzmann, Group III-nitride-based gas sensors for combustion monitoring, Mater. Sci. Eng. B 93,207-214 (2002). 

The USS Essex and three other LHD-class amphibious assault ships utilize furnace cameras to observe flame patterns and identify potential problems in a boiler combustion monitoring system and also monitor a pushbutton igniter-control system. Previously, a sailor monitored the fires through a small porthole, and an engineer in a flame-resistant jacket lit the boilers with a torch. If unburned fuel was in the boiler, explosions could occur. 

For the use of combustion monitoring, a TiOj semiconductor NO sensor has recently been developed by Satake et al.[25] of Tokuyama Soda, Japan, and is... 

In consumer s use, applications of gas sensors related to environmental pollutant gases are carried out mainly for security and amenity. Examples of the applications are, for instance, in the protection from a incomplete burning of combustion apparatus for home use and in the ventilation or condition of indoor atmosphere. A combustion monitoring sensor using SnOj was developed by Tanaka et al.[110] of Figaro Engineering, Japan. The gas water-heater... 

Schalwig, X, MilUer, G., Eickhoff, M., Ambacher, O. and Stutzmann, M. (2002), Group Ill-nitride based gas sensors for combustion monitoring. Materials Science and Engineering B, 93,207-14. 

Sassenscheid K, Klocke U, Marb C, et al. (1998) Dynamic derivative UV-spectroscopy for combustion monitoring. Proceedings of SPIE 3535 204-214. 

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