The effects of particle behavior on the heat transfer of a shallow fluidized bed

In order to clarify the correlation of heat transfer and particle behavior around the tube surface, surface temperature and particle volume-fraction coming to contact with the tube surface were measured simultaneously by using thermocouples and a fiber optical probe at 5 locations around a heated tube surface. The fiber optical probe had two rods, one was connected to a light emitting diode (LED) and the other was connected to a photo-cell, which were separated from each other by a distance of 4mm, and this distance was chose to be about 10 times the mean particle diameter of 0.40mm. Experimental results show the local heat transfer rate closely depends on the particle volume-fraction and the particle residential time. The located angle of its maximum shifts from 135°to 120°, this being measured from a stagnation point, as the fluidized gas velocity increases.