Development Of Surfactant-magnetized Water And Study On The Performance Of Spray Dust Removal And Temperature Reduction

With the rapid development of tunneling technology in mines,the depth of mining is constantly increasing,resulting in serious dust pollution and heat damage hazards,threatening the health of underground workers and the safe production of enterprises.Spray dust removal and temperature reduction has been widely used because of its convenience and rapidity.But the dust removal efficiency of pure water spray is low for strong hydrophobic dust.And the low degree of atomization and low specific heat capacity of pure water spray also affect the cooling efficiency.Research on the comprehensive performance of dust removal and temperature reduction of surfactant-magnetized water is not deep enough at present.In this paper,on the basis of theoretical analysis,a combination of experimental research,numerical simulation and engineering application design is used to study the development experiment of surfactant-magnetized water,simulation of spraying conditions,simulation of spraying dust removal and temperature reduction efficiency and optimization design of spraying device.Firstly,surfactant-magnetized water was developed through experiments.The 3types of physicochemical performance parameters,namely surface tension,viscosity and specific heat capacity of the solution,were measured experimentally.3 groups of surfactant compounding types and 3 compounding mass ratios were selected through surfactant monomer experiments and compounding experiments.Magnetized water experiments were conducted under different magnetic field conditions,and 3 groups of magnetized conditions for treated water were selected.Orthogonal test was used to study the synergistic effect of surfactant and magnetization magnetization.The experimental results showed that the best treatment condition is the magnetization of anionic active agent SDS and nonionic active agent XL40 mixed in a mass ratio of 6:4at a magnetic field strength of 150 m T for 80 s.After treatment,the surface tension of the solution is 27.6 m N/m,the viscosity is 0.91 m Pa·s,and the specific heat capacity is4.632 k J/kg·K The dust removal and temperature reduction performance of the solution is greatly improved.Secondly,numerical simulations were conducted to determine the spraying conditions for more adequate spray atomization and to compare to the advantages of improvement of surfactant-magnetized over pure water in terms of dust removal and temperature reduction.The simulation results show that the spray pressure of surfactant-magnetized water spray is about 63.7%less than that of pure water to achieve the same atomization effect,and the spray field coverage is larger.The highest concentration of pure water spray is 0.007 kg/m~3,while the concentration of active magnetized water spray can reach 0.01 kg/m~3 at the center of the jet.The surfactant-magnetized water spray concentration increases by about 42.9%.After 20 s of dust reduction by spraying,the dust concentration in the tunnel is greatly reduced.With the increase of inlet air speed,the dust concentration in the tunnel shows a trend of increasing first and then decreasing.The dust concentration in the tunnel is maximum when the wind speed is 2 m/s.The efficiency of surfactant-magnetized water spray for dust removal is higher than that of pure water spray at different air inlet speeds.When the initial concentration of dust reaches 0.024 kg/m~3,measures such as extending the spraying time and installing additional nozzles are required to improve the dust reduction capacity.Using a single nozzle for local temperature reduction,the temperature in the roadway drops to an acceptable level when the wind speed of surfactant-magnetized water is 0.2～0.6 m/s and the pure water spray is only 0.2～0.4 m/s.After spraying for20 s,the surfactant-magnetized water spray can reduce the temperature within the range of 10～50 m of the roadway to an acceptable level at the wind speed of 2～4 m/s and pure water spray only at the wind speed of 3 m/s.The surfactant-magnetized water spray has a high cooling efficiency.After the inlet air temperature reaches 35℃or more,the spray cooling effect is poor and additional cooling measures should be taken.Finally,the surfactant-magnetized water spray system is optimized by focusing on surfactant quantitative addition system,magnetization device,and spray dust removal and temperature reduction device.The selection and parameter calculation of related equipment were also carried out.This study can provide theoretical guidance for relieving dust pollution and high temperature heat damage in mines.