EQUIPMENT - 2-INCH-DIAMETER HIGH-PRESSURE FLUID BED
Hazen’s two-inch-diameter, high-pressure fluidized-bed furnace is designed to evaluate fluidized-bed processing for pressures up to 100 psig and temperatures as high as 1,000°C (1,850°F). This unit has been used for coal gasification studies under pressurized conditions, for reduction roasts of ores and concentrates, and for chemical conversions of minerals and other materials requiring conditions of high temperature and pressure.
The two-inch-diameter furnace, constructed of 316L stainless steel, has a total height of six feet followed by a four-inch-diameter expanded freeboard area for dust disengagement. Electrical resistance heaters, encased in an insulating shell, externally heat the furnace to maintain desired operating temperatures. Thermocouples are placed at various heights within the fluid bed to monitor process temperatures during testing.
When the process requires mixed gas atmospheres, this unit is configured so that fluidization gas is provided from appropriate cylinders through pressure regulators, and the required mixture is fed into the fluid bed by a compressor. Exhaust gas is cleaned in a dust-collecting cyclone followed by a baghouse and gas cooler, then is recycled to the fluidizing compressor. If required, a portion of the exhaust gas can be bled from the system to allow for the addition of fresh fluidization gas.
Solids can be fed to the unit either continuously or batchwise. Typical feed rates range from one to two pounds per hour, and batch processing tests can utilize one to eight pounds of material.
The system is equipped with online instrumentation to obtain operating data. Process temperatures, pressures, and gas compositions, including O2, CO2, CO, SO2, NOx, and total hydrocarbons (THC), are monitored and recorded continuously. A gas chromatograph and mass spectrometer are available for measuring other gaseous constituents, such as water, hydrogen, nitrogen, and methane. A data-acquisition system is used to monitor and record selected process data. Emission sampling for organic compounds, metals, and other inorganic species can be performed as required, using EPA-approved methods.