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Statistical Design Case Study

Using Dependent Variables

Problem

Design a two-level, three-variable full-factorial experiment (i.e., 23).  The locations for experiments are 40 and 48°C for exhaust temperature, 15 and 25% for exhaust relative humidity, and 100 and 300 g/min for spray rate.  The inlet air dew point is 6°C and inlet air relative humidity is 3%, the heat loss is 2.5 kW, atomizing air is 30 SCFM, and the aqueous coating solution contains 10% solids.  Calculate the inlet air flow rate and temperature needed to achieve these conditions for these runs.

Problem Categories

Other dependent variables, for example weight gain and coating uniformity, may be used for similar analysis using the simulation tools.

Applies to all categories and all products.

Solution

The reverse calculation option in the thermodynamics screen is used to determine the process air flow rate and temperature to achieve the design conditions based on the dependent variables.  For the '---' design point (40°C, 15% RH, and 100 g/min), the results are 2348 SCFM and 45°C as shown below.  This procedure is repeated for the other design points.
Results