FIGURE 1 1) Hose between the air compressor and air flow meter, 2) Air flow meter, 3) Venturi injector, 4) Nebulizer, 5) Heater, 6) Heater control knob, 7) Thermometer with K-type thermocouple, 8) silicone hose, 9) Ice molds, 10) Gelatin filter holder, 11) Aspirator
A detailed illustration of the electric heater is shown schematically in Fig. 2. The body of the heater was made of a metal sheet with a thickness of one mm. In the heater, an electric heating coil was located perpendicular to the air flow and used as a thermal energy source. The heater’s airway cross-section area is 4x4 cm2 with a length of 25 cm. The heating coil occupies 15 cm of the heater. The thermocouple was located at the outlet of the heater to measure the outlet temperature. Outside of the heater was isolated using a fiberglass slab.