Research On The Bubble Discharge In Water And The Concentration Of The Products Control Mechanism

Plasma discharge in water is a new technology of water treatment that produces strong oxidizing substances such as ·OH,·O,H 2 O2 and O 3,which have a significant effect on the degradation of harmful substances and the killing of bacteria.However,for the demand of household appliances,there are still problems.First,the discharge in water requires an electric field of 107-109v/m.Moreover,the control mode of discharge intensity depends on the regulation of high voltage power supply.In the process there is a high risk and the regulation range is limited.To the challenge of intensity control of discharge in water this paper presents a method to control the start and stop of discharge by bubble and the treatment intensity by gas flow.First,a stable discharge needle-net bubble discharge structure is set up.Based on the discharge signals and images,the reasons for the randomness are analyzed.The frequency of bubble discharge was taken as the index to study the structure parameters,and a stable bubble discharge structure was obtained.The bubble discharge frequency can increase with the increase of gas flow.Secondly,the influence of air and water medium parameters on discharge is studied.The effect of solution conductivity,temperature and different gases on discharge was studied.The effect of conductivity on discharge was solved by the improvement of the structure,and the discharge frequency can be increased with the increase of gas flow at higher conductivity.Thirdly,the experimental study on the concentration characteristics of bubble discharge products was carried out,in especial the H2 O2 and O 3.The results show the concentration of each product can be increased with the increase of the gas flow rate,which has a good control effect on the concentration of the products.And the concentration of the product can be increased by multi-pin parallel discharge,and the gas flow can still control the concentration of the product.Finally,on the basis of the regulation of the gas flow rate on the bubble discharge frequency and the products concentration,the characteristics of each product and the test difficulty are analyzed,and ozone is determined as the control object.An ozone concentration feedback control system was established,and the gas flow was used to control the concentration of discharge products in two ways,“Gas direct on-off” and “Gas continuous regulation”.