Study on ventilation performance of lateral exhaust hood under the influence of two high-temperature buoyant jets

Abstract

Two high-temperature buoyant jets widely exist during the pouring process of molten metal. The lateral exhaust hood is usually used to capture contaminated airflow considering production process. However, the current flow ratio design method for the lateral exhaust hood is in consideration of a single pollution source. In this study, the applicability of the current flow ratio design method for controlling two high-temperature buoyant jets is analyzed. And the performance of lateral exhaust hood influenced by these two buoyant jets is investigated through model experiment and numerical simulation. Investigated factors are distances between two high-temperature buoyant jets, initial velocity ratios, and initial temperature ratios. The results show that the maximum capture efficiency is less than 60% when the optimal exhaust flow rate for controlling the single-buoyant jet is doubled to control the two buoyant jets. Besides, with the distance ratio between the two buoyant jets increasing to 0.75, the two jets merge into one jet. Then, compared with that when the velocity ratio is 0.4, the dimensionless installation height of the lateral exhaust hood should be increased by about 0.04 when the velocity ratio is 1.0 and by about 0.12 when the velocity ratio is 1.4. Finally, with the temperature ratio increasing, the lateral exhaust hood flowrate should be increased to improve the capture efficiency instead of exhaust hood installation heights. In summary, the obtained conclusions could help develop high-efficiency ventilation systems and reduce the energy consumption of the industrial buildings.