Fluidized Bed Experiment

This report provides an analysis of the fluidization process of a solid in a stationary fluidized bed. The heat transfer and hydrodynamic characteristics of a fluidized bed were determined to evaluate if the operating parameters for the system could be verified by empirical correlation. Two parts to the experiments were performed. The first part studied the effect of a changing air flow rate with pressure at a constant temperature. A range of air flow rates from 0.15 to 3.5-g/L were used. In the second part, the effect of the air flow rate at constant heater temperature and changing power was studied. The same range of air flow rates were used and tested at three heater temperatures of 100, 125, and 150°C.

The minimum fluidization velocity,

The ideal results of the experiment are that the results of the experiment thoroughly analyze operations of a fluidized bed, and that the results are supported by empirical expectations.

The purpose of this experiment was to study the hydrodynamic and heat transfer characteristics of a fluidized bed through determination of the minimum fluidization velocity, the heat transfer coefficient, and the maximum heat transfer coefficient. These experimental values were then compared to the empirical correlations to ascertain if the fluidized bed functioned as expected. A variety of parameters were calculated throughout the process to solve for the final values, including: the calibration constant, Reynolds number, Prandl number, the void fraction, Archimedes number, and the Nusselt number.

The calibration constant for a fluidized bed is necessary to determine because the flow rate cannot be measured from a flow meter at high air velocities, but must be calculated. The method to determine the calibration constant is through use of a manometer to measure the change in pressure and the air flow rate at low flow values. The calibration constant can be determined using Equation 1

The Wen and Yu correlation for the minimum fluidization velocity is determined using Equation 3 below [3].

In addition to the determining the heat transfer coefficient from experimental data, it can be calculated through correlations. The Vreedenburg correlation can be used to calculate the heat transfer coefficient through a variety of dimensionless numbers [2]. To determine the heat transfer coefficient, the Reynolds number and Prandl number must be calculated. These values can be determined using Equation 8 and 9 below.

Once all the values from the equations have been determined, the final results can be compared to the correlations. The expected results of the experiment are that the minimum fluidization velocity and heat transfer coefficient values are comparable to literature correlations for a fluidized bed

A fluidized bed was used to collect data to study the effect of air flow and heat on a fluidization process. In the experiment, air and heat were applied through a glass cylinder filled with fused alumina at fluctuating pressure values and adjusted flow rates. This was completed to determine the minimum fluidization velocity for the system, the heat transfer coefficient at different temperatures, and the maximum heat transfer coefficient. The experimental apparatus used is shown in Figure 1 on the next