Air Turbidification Technique

Figure 2 illustrates a layout of pilot-scale air-dehumidification test-stand. Compressed air is passing through humidifying system, water trap, and separation unit. 240 L/min of dry air is supplied by the compression division at 10 bars to the water-humidifier before heading to the stainless steel C-D nozzle and separation unit.

Dimensions of the rectangular nozzle, sketched in Figure 3, are tabulated in Table 1. It is convenient here to mention that the length of the convergent portion and divergent portion of the nozzle is calculated to match the available experimental data. The dimensions of the nozzles were evaluated using the procedure elaborated in appendix A.

The pressure, temperature, humidity ratio, and dew point of the air stream at inlet and exit of the nozzle system were measured. An uncertainty analysis due to instrumentation and measurement accuracy is performed as follows:

The maximum error is estimated to be 2.4% for the relative humidity and 0.54oC for the temperature. Two pressure gauges were mounted at both the entrance of the convergent part and the exit of the divergent part. The precision of these gauges is ±0.4% with an estimated maximum error of 2%.

The outcome of the numerical simulation performed for the 3-D convergent-divergent nozzles concludes that the separation equipment should be mounted near the throat when the Nozzle Pressure Ratio (NPR), defined as the ratio between the nozzle’s inlet stagnation pressure and the exit atmospheric pressure, is relatively small [19]. Hence, we relied on this conclusion during construction of the