(52d) Desktop Experiment: Pressurized Tank

All first year engineering students enroll in an ?Introduction to Engineering? course which was developed to strengthen students' math skills. Laboratory exercises show applications of math in engineering. For one laboratory, we constructed a simple pressurized tank which models the solution of a differential equation. Students pressurize the tank, then open a valve with a small orifice (0.013? diameter) and note the pressure at intervals of 1 ? 2 seconds. They first graph their data on semilog paper to convince themselves that the solution of the differential equation is exponential, then use Excel to estimate the parameters. Students in the Process Control course will repeat the experiment and develop a first order model of a pressurized tank, estimating the gain and time constant.

An assessment of the experiment will be available by November 2010.

The tank was constructed from 2? threaded galvanized steel pipe and threaded head caps. It is mounted on an aluminum base. The students use a bicycle pump to pressurize the tank (to 30 psi, although it is capable of withstanding pressures of 100 psi). The total cost of each unit was $ 68.40.