Experiments for Hydrogen Chloride Transport and Decay in a Simulated Heating, Ventilating and Air Conditioning System and Comparison of the Results with Predictions from a Theoretical Model

The transport of hydrogen chloride (HCl) gas in air was studied in a simulated heating, ventilating and air conditioning (HVAC) system. The test system was a tube of square cross section, 0.305 m (1 ft) on each side, with a total length of ca. 120 m. The sides of the apparatus were built of painted and unpainted gypsum wallboard, and poly(methyl methacrylate) (PMMA), ar ranged in two different configurations. All four tests were run at normal room temperature. Hydrogen chloride gas was injected into the air at the entrance to yield initial HCl concentrations of ca. 3,000-4,000 ppm (vol). The experiments were typically conducted for 30 min. Gaseous HCl concentrations were mea sured at 9 locations along the conduit, and the results were compared with pre dictions from an existing model for HCl transport and decay from fire at mospheres. The model was used in a purely predictive mode, i.e., unchanged, since the flow dynamics are well defined in this scenario and since HCl decay parameters for each type of surface used had been developed for the model in previous studies.