Research On Control Of Gas Pollutants In Grinding Wheel Production Plant

Various harmful substances emitted during the industrial production process include gas pollutants,particulate pollutants,waste heat,and residual humidity.If they are not controlled,they will not only cause indoor and outdoor environmental pollution,but also affect the health and efficiency of the staffs.This article that through the literature review and site test and numerical simulation of a grinding wheel production plant in Hebei Province,to determine the gas contaminant components and pollution levels in the resin grinding wheel production process.This article selected thermal pressure natural ventilation,mechanical ventilation and air conditioning of different combinations of operating environment control method for numerical simulation.This article analyzed the main problems of ventilation and air conditioning system and the characteristics for distribution of gas pollutants in workshop space,and explored the relevant rules effect to control the shape and position of the ventilation outlet and gas pollutants.With the characteristics of the profile and the layout of the production site,an improvement plan for the air-conditioning ventilation system with the objectives of control and energy-saving operation of gas pollutants was proposed.This paper analyzed and studied the anti-escaping and effective collection of gas pollutants,and obtained the shape of the mechanical exhaust outlet with good control effect and the height from the processing platform,which could be applied to the design and installation of gas pollutant control project.The main research contents and conclusions are as follows:(1)Through site investigation and numerical simulation analysis,it was concluded that the choice of the air-conditioning and ventilation systems of the plant,the layout of the tuyere and the piping must take into account the factors such as the distribution of the pollution sources,the release of pollutants and their characteristics.Not suitable for setting up air-conditioning systems for air circulation in the presence of dust pollution in the plant.High-energy consumption resulting from the use of full ventilation under dispersion of pollution sources and non-enclosed processing conditions could be compensated by the use of natural ventilation and the installation of a direct-flow new air conditioning system with heat recovery.(2)Based on numerical simulation,the setting height of the mechanical exhaust port was optimized.Through the analysis of the distribution of phenol concentration in the workshop at different heights of the mechanical exhaust port,the most suitable mechanical exhaust port position was obtained.From a height of 1m above the processing platform,the phenol concentration at the site of the test point(employee station site)was reduced to the maximum allowable concentration of 5.0mg/m~3 or less.(3)The phenol concentration in the field test point at the site where the mechanical exhaust port is 1m high is in line with the indoor environment requirements of the industrial plant,but the concentration of phenol in some non-test points is still exceeding the standard.Through the analysis,it was found that the rectangular exhaust outlet whose ability was not good to collect pollutants and prevent escaping.In order to increase the wind collecting effect of the mechanical ventilation outlet,the flaring design was adopted for the mechanical exhaust outlet.The simulation results show that the concentration of phenol had been effectively controlled after the flaring of mechanical exhaust outlets,but there is no significant difference in the control effect of phenol concentration at the test point when the flare was used at different expansion angles.(4)Based on the problem of cold and heat losses caused by mechanical exhaust systems and DC air-conditioning systems,the energy-saving design of the ventilation and air conditioning system of the plant was studied,by setting the sensible heat recovery device to preheat and precool the fresh air.The annual temperature change curve chart of Cangzhou city was used to analyze the annual energy saving effect after the sensible heat exhaust heat recovery device was installed in the workshop,and the energy saving ratio calculation method was adopted.It was concluded that the energy saving ratio was 15%under the summer conditions.Under the winter conditions,the energy saving ratio was 33.7%.The used of exhaust heat recovery devices had significant energy savings.