Long-duct forced and short-duct exhaust ventilation system in tunnels: Formation and dust control analysis of pressure ventilation air curtain

2019 ◽  
Vol 132 ◽  
pp. 367-377 ◽  
Author(s):  
Qiang Liu ◽  
Wen Nie ◽  
Yun Hua ◽  
Huitian Peng ◽  
He Ma ◽  
...  
Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kuan Wu ◽  
Shiliang Shi ◽  
Yijie Shi ◽  
Yong Chen

Dust is one of the main pollutants in coal mines, which seriously affects the physical and mental health of workers, as well as the safe production in underground mines. Dual-radial swirl shielding ventilation is a new ventilation method for a fully mechanized excavation face and can effectively reduce the dust concentration in the underground. The dust control effect of dual-radial swirl shielding ventilation is mainly affected by the thickness and integrity of the shielding air curtain, as well as the disturbance of the flow field near the air curtain. By changing the blowing and suction air volume ratio of the air duct, the strength of the radial air curtain can be improved, and the dust control effect of the dual-radial swirl shielding ventilation system can be effectively improved. In order to determine the optimal operating parameters of the dual-radial swirl shielding ventilation system, a numerical simulation method was used to conduct an in-depth study on the blowing and suction air volume ratio of the system. The results showed that when the blowing and suction air volume ratio of the air duct was 1.5, the radial air curtain had the highest strength. Under this condition, the dust concentration at the driver’s position of the roadheader was the lowest, and the dual-radial swirl shielding ventilation system can achieve an ideal dust control effect.


2018 ◽  
Vol 875 ◽  
pp. 137-140 ◽  
Author(s):  
Valery N. Azarov ◽  
Natalia M. Sergina ◽  
I.V. Stefanenko

It was proposed to use air flow screw straightened units in outlet pipe of the dust collectors to reduce the aerodynamic resistance of exhaust ventilation systems. It is allowed to decrease power consumption for their maintenance operation consequently. The article describes the results of experimental studies to evaluate its effectiveness by applying the tangential screw straightened unit within ventilation system. The obtained results showed that the use of this device allows reducing the aerodynamic resistance of the cyclone by 14.6%, and for counter-swirling flows’ dust collector (CSFC) by 17.2-23.6%. It was found that meanings of the aerodynamic resistance depend on value the share proportion of the flow entering into lower CSFC apparatus’ input.


Solar Energy ◽  
2005 ◽  
Author(s):  
D. Dong ◽  
M. Liu

Investigations of a desiccant dehumidifier system have been performed for humidity control application in confined spaces. A previous study revealed that the base dehumidifier system can reduce moisture condensation by 22% over a conventional exhaust ventilation system. The current study aims to develop improved design requirements for a desiccant dehumidifier. The energy consumption of an exhaust ventilation system and an improved dehumidifier system was compared. To investigate the improved desiccant dehumidification system, numerical simulations were conducted and an objective function was established. This paper presents simulated results for an existing desiccant dehumidification system and an improved system, in which improved parameters are used. Use of the improved design parameters can reduce moisture condensation by 26.6% over a base dehumidifier system and shorten the dehumidifier performance period by 14%. Energy consumption with the sole use of an exhaust system is compared with that of the improved dehumidifier system under the same conditions. The results show that energy consumption can be substantially reduced, by 63%, in the improved dehumidifier system with the same amount of moisture condensation on surfaces of the confined space.


2013 ◽  
Vol 824 ◽  
pp. 217-224
Author(s):  
E.O. Ifelola ◽  
D.J. Afu

Dust control in an enclosed mine environment is a fundamental key to personnel safety for boosting personnel productivity and enhancing successful operation, hence the need to design a dust control equipment to meet this crucial requirement. A laboratory-scale local exhaust ventilating system for the control of airborne dust in an enclosed mine environment was designed and fabricated. The design was carried out by considering various design criteria required for a well-ventilated enclosed mine environment. Material selection of the components was done by taking into cognisance the physical characteristics of the targeted dust. The system designed was fabricated and then test-ran with dry dust laden air stream in order to determine its cleaning efficiency with respect to variation in fan speed and dust grain size. It was observed that the cleaning efficiency of the machine was high at a higher fan speed and low grain sizes. The cleaning efficiency ranged from (63.9-44.0)% for dust particle sizes ranging from (62.5-125) to (1000-2000) μm with a mean fan suction of 0.958Pa. Thus, with this system, improved cleaning of dry dust-laden enclosed mine workplace could be achieved with increased rate of suction of smaller particle-sized dust.


2020 ◽  
Vol 33 (2) ◽  
pp. 310-315 ◽  
Author(s):  
Tee Lin ◽  
Omid Ali Zargar ◽  
Oscar Juina ◽  
Tzu-Chieh Lee ◽  
Dexter Lyndon Sabusap ◽  
...  

2012 ◽  
Vol 241-244 ◽  
pp. 1285-1292
Author(s):  
Gang Zhou ◽  
Sen Cao ◽  
De Ming Wang ◽  
Wei Min Cheng ◽  
Wen Nie

Vortex air curtain of plane wall fan drum can control the diffusion of air stripping dust effectively. In order to solve the high-concentration dust problem in fully mechanized excavation face, formation mechanism of vortex air curtain was analyzed. According to fluid mechanical control equations of gas phase flow, mathematical model was established to solve air migration law of vortex air curtain in fully mechanized excavation face. By using Simple algorithm based on collocated grid and fluent software, numerical simulation of air spatial migration law of closed-end dust control in fully mechanized excavation face was carried out. The simulation results show that vortex air curtain dust control system can form dust control fan drum along driving head to the front of the roadheader driver. According to the simulation results and actual conditions of working face field, vortex air curtain suction dust control system consisted of plane wall fan drum and exhausted dust purification device in fully mechanized excavation face was designed, and after it was applied in fully mechanized excavation face, the dust concentration decreased effectively in the working face field.


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