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Evaluation of proposed ventilation equations for exothermic process control.

American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois. Fairfax, VA: American Industrial Hygiene Association, 2006 May; :53
Our understanding of heat transfer and meteorological theory, and their applications for engineering control design, have evolved since Hemeon first published his research on heated process control in 1955. These refined theories were reviewed to develop a newly proposed equation to estimate buoyant plume volumetric flow. To determine which equations were most accurate, the proposed, ACGIH, and Hemeon's equations were compared to direct measurements of buoyant flow parameters from laboratory experiments. Two hundred laboratory data points were collected at various excess temperature and height combinations using a hot-wire anemometer and a model exothermic process. The comparison of the three equations to experimental results was conducted by using multiple one sample T-tests for differences between the experimental data and solutions to each of the three equations. Statistical comparisons (difference of means, standard deviation and p values) of the volumetric flow from the experimental results and solutions from the three equations indicated that the ACGIH equation provided results that slightly overestimated the laboratory volumetric flow (ACGIH: 0.02, 0.30, 0.65). The proposed equation slightly underestimated the laboratory volumetric flow; however, it provided better overall results than Hemeon's equation. Examining the p values, it can be seen that the proposed and the Hemeon equations provided results that were different from the experimental data (proposed: -0.06, 0.16, 0.03; Hemeon: 0.13, 0.35, 0.02). Overall, the proposed equation provides a slight underestimation of volumetric flow; however, this estimate has considerably less variability than either of the currently accepted equations. Benefits of the proposed equation are its ease of application, basis in well-developed heat transfer and meteorological theories, and lack of subjective safety factors that are built into the other currently accepted equations.
Heat; Engineering-controls; Volumetric-analysis; Mathematical-models; Laboratories; Laboratory-testing; Temperature-effects; Temperature-measurement; Models; Statistical-analysis; Ventilation; Ventilation-systems; Control-technology
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American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois