Research on a push-pull industrial trough-side exhaust hood based on CFD simulation and experiment

The traditional industrial trough-side exhaust hood requires large energy consumption for one-way airflow because the air inlet and outlet are on both sides of the industrial slot. In this research, based on the improvement of the traditional push-pull trough-side exhaust hood, a double-sided symmetrical push-pull industrial trough-side exhaust hood is researched. Simulation software ICEM and FLUENT were used to research the relationship between the distance of air inlet and outlet and the air volume ratio, and the relationship between the air volume ratio and mass fraction of pollutant gases, using carbon monoxide as the pollutant gas. The research found that when the pollutant mass fraction reaches the specified level, the air inlet and outlet distance is quadratically related to the air volume ratio. When the distance between the inlet and outlet is 0.12 m and the corresponding minimum flow ratio is 1.7, the interference of the suction air outlet pressure on the blowing air outlet jet reaches the minimum. By comparing the energy consumption with the traditional industrial trough-side exhaust hood, the energy saving rate is 75.8% with the same pollutant control effect. The double-sided symmetrical push-pull industrial trough-side exhaust hood reduce the cost of treating and discharging pollutants and provides a new idea for industrial pollutant treatment.

[Study on flow field characteristics of dust airflow in vibrating screen and optimization of dust removal system]

In order to solve the problem of dust hazard of vibrating screen machine and difficult treatment in catalyst production process, computational fluid dynamics software Fluent was used to carry out numerical simulation calculation of the local exhaust dust removal system for the main dust dispersing points of the vibrating screen machine, including fine/coarse particles outlet and product outlet blowing and cleaning the dust points. The optimal design scheme and key technical parameters of local ventilation and dust removal system of vibrating screen machine were proposed. The results showed that the dust diffusion could be prevented by setting up an upper suction hood without air blowing, but the exhaust air volume needed to be calculated accurately. On the premise of purge, it is necessary to control the air volume to form a wind speed band of 8 m/s with a height of 15 cm at the feed port, so as to effectively remove the dust on the surface of solid particles of catalyst products and ensure that the catalyst products will not be blown away when falling into the feed barrel. The simulated design was applied to the vibrating sieve powder machine of a catalyst company, and the maximum dust concentration in the workplace was reduced from 45.80 mg/m(3) to 5.46mg/m(3), which effectively improved the working environment in the workplace.

Research on the axial velocity change rule of desktop slot exhaust hood

The desktop slot exhaust hood has been widely used, but it is calculated by empirical formula. Axial velocity change rule of desktop slot exhaust hood can effectively provide the basis of the wind speed needed in order to control the poison. According to gas motion mathematical model, the geometry model and boundary conditions of desktop slot exhaust hood was established, and the influence of the hood sizes to axial velocity were analyzed by Fluent simulation. The changes of relationship between the axial velocity (V) and the distance from the hood mouth (L), the short edge of the hood mouth (a), the long edge of the hood mouth (b), the equivalent diameter of the hood mouth (d) and the square root of the hood mouth area (√A) were comparative analyzed by dimensionless processing. The result is the V/V₀ with L/d have better change rule. The axial velocity change rule of different axial velocity were also analyzed using V/V₀ with L/d change rule, and the change rule of V/V₀ with L/d of desktop slot exhaust hood was obtained, which was verified by experiment.