100,000 BTU/hr Multi-fuel Furnace

Purpose

The 30 kW down-fired U-furnace is uniquely suited to studying combinations of NOx control technologies, including burner modification, staging, reburning, and SNCR (Selective non-catalytic reduction). The U-furnace burns 100,000 Btu/hr and is designed to accept several fuels including natural gas, pulverized coal, wood, and oil.

Physical Description

• Inner diameter: 15 x 15 cm
• Total length: 6.7 m
• Maximum temperature: 2150 K
• Typical feed rate: 4 - 5 kg/h residence time at full load: 2.5 s

The six-inch inner diameter furnace is down-fired, with a total length of 22 ft. The U-furnace was built in seven sections, and the burner is fired in the top of the first vertical section. The first three sections of the furnace are designed to withstand temperatures of up to 3400°F. The coal feed rate is typically eight to ten pounds per hour, and at full load the furnace residence time is 2.5 s. The horizontal portion of the furnace includes provisions for heat removal while the downstream vertical section includes auxiliary burners inside the refractory that can be fired counter currently to the main flow to maintain isothermal conditions in the final vertical section.