Study On The Purification Performance Of Tube Ribbed Photocatalytic Reactor

With the widespread use of a large number of new building decoration materials,indoor air pollution has increased further.Indoor building materials continue to volatilize large amounts of chemicals,which can build up in indoor spaces and form volatile organic compounds.Aerosol in indoor air carries a variety of microorganisms including bacteria,viruses,fungi and their byproducts,forming microbial aerosol pollution that causes many asthma,allergies,infectious diseases.As people’s living standards continue to improve,it is urgent to reduce indoor pollutants.The photocatalytic technique can degrade volatile organic compounds at normal temperatures and pressures.UV sterilization inactivates microorganisms by attacking nucleic acids.In this way,organic pollutants and microbial pollution in indoor air can be efficiently purified by combining the two technologies.In view of this,the following research work was carried out.(1)Based on the tubular photocatalytic reactor,the number of fins was determined by referring to relevant data,and formaldehyde was taken as the target pollutant to conduct experiments,through which the improvement effect of the tubular photocatalytic reactor’s purification efficiency compared with that of the tubular photocatalytic reactor was evaluated.The results show that the tubular photocatalytic reactor has a relatively good ability to purify formaldehyde,but with the addition of the fin,the photocatalytic purification is more efficient and formaldehyde can be easily degraded to less than 0.080 mg/m~3,whereas the non-fin reactor requires a longer degradation time.(2)The effects of air velocity and irradiance on formaldehyde conversion in high concentration and low concentration formaldehyde environments were explored through experiments in a tubular ribbed photocatalytic reactor.The results show that the degradation rate of formaldehyde is more sensitive to changes in airflow velocity in environments with high formaldehyde concentrations.In the low concentration regime,where the flow velocity is less than 2.0 m/s,there is no significant change in the conversion rate.The optimal flow rate is 2m/s at high formaldehyde concentrations.When the formaldehyde concentration is low,the optimal flow velocity is 1 m/s considering the resource savings.Unlike the effect of air velocity,the change in conversion rate due to irradiation is not affected by the initial concentration of formaldehyde.The ability to degrade formaldehyde is enhanced with increasing irradiance.(3)TracePro software was used to simulate the irradiance inside the reactor,and a shafted analysis surface was established to analyze the irradiance data and compare the influence of increasing fins on irradiance.The results show that the fins in the reactor block light to some extent,so that the irradiance near the fins is relatively low.However,the irradiance in the middle region of the finned reactor is slightly increased compared to the non-finned reactor due to the diffuse reflection from the finned surface.(4)The operating wind speed of the reactor in the environment of high concentration and low concentration of formaldehyde was determined,and the bactericide performance of the tubular ribbed photocatalytic reactor was analyzed by combining the simulation results of the irradiance of the ribbed reactor with different light sources and the residence time of microorganisms.The results show that the tubular ribbed reactor has a considerable ability to inactivate bacteria and viruses at flow rates of 1 m/s and 2 m/s,with a killing rate of up to 90%.Inactivation of bacterial spores,fungal cells,yeast,and fungal spores was relatively poor.Tubular ribbed photocatalytic reactors are used in everyday office or home life and their purification capacity can meet the needs of people.