Drop Tube Furnace Test Facility
Overview
Drop Tube Furnace Test Facility at TU Hamburg-Harburg
Drop Tube Furnace Test Facility of TU Hamburg-Harburg
Combustion chamber
dimensions:
Inner diameter 0.15 m, length 2.00 m
Wall temperature: 900...1600 °C
(5 independently regulated modules )
Test atmospheres: Air and various mixtures of O2, CO2, H2O, N2
addition of NOx and SO2
  Primary, secondary and tertiary combustion gas with the further possibility of gas staging
Residence time: Up to 2 seconds
Measurements: CO2, O2, NOx, SO2, CO,
Temperature by side-gated inspection ports
  Fuel and ash analysis

Description
The inside of the glowing Drop Tube Furnace under operation
The inside of the glowing Drop Tube Furnace under operation

For studying experimentally the combustion processes in the Oxyfuel Process the Institute of Energy Systems possesses a Drop Tube Furnace. This consists of a 2 m long electrically heated ceramic tube of 15 cm diameter, in which temperatures of up to 1600 °C can be obtained.

By means of a burner pulverised coal, mixed with primary combustion gas, is fed into the furnace. The mixture then burns inside the reactor. As oxygen carrier it is possible to use air or a varying mixture of O2, CO2, N2 whilst a steam generator supplies additionally steam.
Furthermore, small amounts of impurities, such as NOx or SO2 can be added, to replicate the gas composition of the recirculating flue gas.

The main combustion gas (O2, CO2) and impurity components (NO, NO2, SO2, CO) are measured.

After coal combustion in the furnace, which requires approximately 2 seconds, the combustion gases are quenched with air. This results in an instantaneous 'freezing' of the combustion process, so that the exhaust gas, after particle removal in a cyclone, can be released directly to the atmosphere. The coals being tested, as well as the resulting ashes from the furnace, are analysed through proximity and elementary analyses.