Combustion Technology

Combustion Technology | Combustion Research Facility | High-Temperature Drop-Tube Furnace

High-Temperature Drop-Tube Furnace (HTDTF)

Figure 1. High-Temperature Drop-Tube Furnace
Southern Research

The High-Temperature Drop-Tube Furnace (HTDTF) at Southern Research is an effective facility for both fundamental research and for screening combustion-related technologies prior to pilot-scale or slipstream testing. The HTDTF facility is shown in Figure 1 and Figure 2 shows the reactor, filter, and housing.

An S-Line solid electric tube furnace is used to heat the reactor walls externally to temperatures as high as 2000°F. The reactor itself is constructed of an incoloy metal that can withstand high temperatures and corrosive environments, without being susceptible to thermal shock. When the experiments desired require it, electric heaters are also used to preheat the incoming gases and the filter housing at the reactor outlet. Gases are metered to the reactor with precision mass-flow controllers, to produce the desired combustion stoichiometry, flow rates, residence times, and additional flue-gas components or pollutants.

Figure 2. Filter Housing - Southern Research

The fuel is added in a variety of different methods, depending on whether the fuel is a liquid, gas, large particles, or a fine powder. Several different feeders are available for feeding powdered fuel, such as the AccuRate Series 300 and TSI 3400, and liquid fuels or slurries can be sprayed in with appropriate pumps, pressurized spraying systems, and nozzles.

Combustion residues, such as fly ash or char, are collected at the exit of the reactor on the small, candle-filter element inside the filter housing, while the gas leaving the reactor is pulled through an MKS 2030 FTIR, which measures the concentration of hydrocarbons, nitrogen and sulfur compounds, CO and CO₂, water vapor, acid gases, and a variety of other important gas species. As desired, the exhaust gases are also analyzed on-line for mercury concentrations or other trace pollutants. The filter element may either be maintained at high temperature across the filter or cooled to quench reactions that might otherwise take place with the char on the filter element. Hence, the HTDTF may be used to investigate gas-phase reactions, combustion products, solid fuel reaction rates, or carbon burnout in char or ash.

Among other things, the High-Temperature Drop-Tube Furnace has been effectively used to evaluate combustion catalysts, obtain reaction kinetics of solid fuels, and to screen sorbents, reagents, or other pollution control technologies, before scaling-up testing to larger facilities.

Combustion Technology | Combustion Research Facility | High-Temperature Drop-Tube Furnace