Volume I - Section IV - Experimental Work and Verification of CFD Methodology 
Page IV - 43 
2) Desiccant drying system-A separate air humidity control system was developed to 
remove moisture from the calorimeter air. To accomplish this, calorimeter air was recirculated 
through a desiccant drying system. The dehumidification system consisted of two diaphragm air 
pumps (approximately 10 L/min each) that pulled air from the calorimeter, passed it through a 
0.30 x 0.10 m (12” x 4”) desiccant cylinder filled with 100 percent CaS0 4 , then returned the air 
back into the calorimeter (see figure 4.34; Dehumidification System). As the air passed through 
the desiccant, it effectively removed all of the moisture. The relative humidity exiting the bottom 
of the drying container was measured to be 0 percent with a Tri-Sense temperature/humidity 
meter (model 37000-00). The air pumps were operated manually based on the relative humidity 
in the calorimeter, which was sensed electronically with General Eastern (model RH-5-V) 
humidity transducers. The relative humidity sensors in each of the calorimeters and in the 
environmental chamber housing the calorimeters were calibrated prior to each 10-day run with a 
psychrometer. The signal from these sensors was collected on a Keithley Metrabyte DAS-8/PGA 
data acquisition system connected to an IBM compatible PC. The signals were analyzed with 
Keithley Metrabyte VIEWDAC software. After each calorimeter test, the desiccant was dried in 
an oven at 220 °C for 1.5 h and reused. 
3) Humidification system-For the high humidity calorimeters, water was added to the air as 
needed to control relative humidity by passing the recirculation air over an evaporative pad (see 
detailed operating procedure for humidification system in appendix I: section 3.3). Water was 
placed in a graduated cylinder above each calorimeter and flowed through a tube to an electric 
solenoid, then into the calorimeters to drip into an evaporative pad (figure 4.34; Humidification 
System). The solenoid valves were opened and closed manually based on the relative humidity 
readings (see detailed operating procedure for relative humidity measurements in appendix I: 
section 3.3). 
