Research on the Uniform Air Supply Technology of the Static Pressure Chamber in a Spray Room

Influence of the Internal Structure Type of a Large-Area Lower Exhaust Workbench on Its Surface Air Distribution

“…The airflow distribution of the surface of the workbench could not be made uniform when only the inclined bottom was used in the large-area lower exhaust workbench, as shown in Figure 3 a and proposed in this study. Yet, a uniform airflow distribution at the hood surface of the static pressure chamber could be achieved when only the inclined roof was set in a spray room, as proposed in reference [ 18 ]. The reason for the opposite results of the two research papers may be that one of the inclined bottom plates was used for the air exhaust and the other was used for the air supply.…”

“…Due to limitations of the working space and operations, the contaminants captured by the exhaust hood can only be exhausted from one side outlet of the lower exhaust workbench, which means the velocity at its farthest point is 0 m/s, as shown in Refs. [ 18 , 19 ]. When the size of the hood face is large, it is difficult to achieve uniform airflow distribution on the hood face so the structures shown in Figure 2 can be used to improve airflow distribution [ 20 ]:…”

“…As can be seen from Figure 2 a–c, an inclined bottom plate is used to achieve a uniform airflow distribution at the hood face, and it is also used to make the supply airflow uniform in the static pressure chamber of a spray room [ 18 ]. Therefore, the two geometries with bottom plate (as shown in Figure 3 a,b) and two geometries with horizontal bottom plate (as shown in Figure 3 c,d) were used for the study.…”

“…The method of CFD simulation is widely used for this kind of application, and the 3D steady-state incompressible Navier–Stokes equations and the standard k-equation model are also used widely used when only momentum transfer is considered and heat transfer is ignored [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. For example, the velocity change rules along the centerline outside the hood with a uniform airflow [ 12 , 13 , 14 ], the influence of the internal structure of the duct [ 15 , 16 , 17 ], the roof structure in a static pressure chamber [ 18 ] and the radius of the 90° rectangular elbow curvature in a lower exhaust hood [ 19 ] have each been studied in terms of airflow distribution using CFD simulations. Yet, the influence of the internal structure of a lower exhaust large-area workbench with an air outlet at the short side of the workbench has not been studied regarding surface airflow distribution.…”

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

“…Wu X. et al studied the influence of a 90-degree elbow on the velocity uniformity of exhaust hoods in parallel push-pull ventilation [ 14 ]. Chen J. et al studied the internal structure of the static pressure chamber in a spray room in order to get the uniform air supply [ 15 ], and also studied the center-line velocity change regime in a parallel-flow exhaust hood [ 16 ] and supple hood [ 17 ]. Wang Y. discussed the effects of the pull-flow velocity on the capture efficiency in a high-velocity jet push-pull ventilation system [ 18 ] and found that the significant reduction in exhaust air flow ratio will not affect the dispersion of contaminants in parallel push-pull ventilation systems [ 19 ].…”