Research on Ventilation Antivirus Technology in a Washing Board Room Based on Numerical Simulation

Changing Patterns of the Flow Ratio with the Distance of Exhaust and Supply Hood in a Parallel Square Push-Pull Ventilation

“…Yang et al [ 10 ] and Liang et al [ 11 ] found that the optimal k value is 2.5 in a push-pull ventilation system, which consists of a uniform push hood and a uniform pull hood with a side length of 0.95 m, and the distance ( L ) between push hood and pull hood is 3.5 m in the push-pull ventilation studied, so L / a = 3.7. The optimal k value is about 2.25, calculated by Equation (3) proposed in this paper, which is about −11% deviation of the calculated k value from the results studied by Yang et al [ 10 ] and Liang et al [ 11 ]. It indicated that the variation patterns of k value with L / a when 1.5 ≤ L / a ≤ 5 proposed in this study is plausible.…”

“…Compared with local exhaust ventilation, push-pull ventilation has better contaminants control due to increased air supply [ 3 , 4 ]. Parallel push-pull ventilation uses the low turbulence intensity, uniform and wide air flow with directionality to push the contaminants into the exhaust outlet [ 5 , 6 ], which has been widely used in workplace contaminants control such as painting [ 7 , 8 ], printing [ 9 ] and cleaning using organic solvent [ 10 , 11 ], welding [ 12 ] and pathology laboratories [ 13 ].…”

“…The design manual [ 20 ] provides an empirical value of flow ratio for the design of parallel push-pull ventilation systems, but it is difficult to design the proper flow ratio in practice of push-pull ventilation design. The optimal air flow ratios of parallel push-pull ventilation system were studied in a washing room [ 10 , 11 ] and a vertical push-pull system [ 21 ], but the application of the results is limited to the specific distance conditions of the push-pull ventilation system. When the conditions change, the results cannot be used.…”

Center-Line Velocity Change Regime in a Parallel-Flow Square Exhaust Hood

“…The mathematical model of gas motion was the same as that employed in previous studies [ 16 , 17 , 18 ]. It was assumed that the air in the flow field is an incompressible Newtonian fluid.…”

“…The center-line velocity change regime for a parallel-flow exhaust hood is helpful to the study of velocity change regime in a parallel-flow push–pull ventilation system, and can further improve the ability of controlling dust and poisonous pollutants for the exhaust hood since its strong anti-interference air flow ability [ 4 , 5 ]. It has a positive effect on reducing the dust and poison in the operating environment and ensuring the occupational health of workers [ 14 , 16 , 17 ]. Therefore, this study aimed to establish the velocity change regime for a parallel-flow square exhaust hood used in a push–pull ventilation system without a parallel-flow push hood, and the results can provide a theoretical basis for improving the ability of controlling dust and poisonous pollutants for the exhaust hood.…”