The Mechanism Of Pulse Discharge In Liquid And Its Applications Of Pipeline Anti-blocking

Technology of high-voltage pulse discharge in liquid occurred in liquid between two electrodes by applying high-voltage pulse, and the process of discharging can produce strong shock waves, ultraviolet, various active, free radicals and the strong electric field. Prior research is limited to single factor of various effects of pulse discharge in liquid were, and various effects produced by discharge in liquid have not been taken into account, especially the relative contribution of free radicals, electric field, ultraviolet radiation and shock waves has not been studied in detail. In this paper, the mechanism and application of the discharge in liquid are studied in detail, and the main conclusions are as follows:First of all, various effects of needle-plate discharge in liquid are separated by the small tubes of different materials to investigation its proportion of multiple effects such as shock wave, ultraviolet radiation, strong electric field and various active free radicals generated in pulse discharge in liquid. In the experiment, the change of distance (d) apart from the discharge point and peak voltage has no effect on the radiation sterilization of the ultraviolet. Unlike ultraviolet (UV), the sterilization of the shock wave decreases when increasing of distance (d). In the experiment, the change of peak voltage has no effect on the sterilization of shock wave. The distance (d) from the discharge point has very significant effect on the sterilization of electric field. The farther the distance is apart from the central axis of discharging, the smaller the sterilization of electric field is. In the center axis of discharging, the proportion of ultraviolet radiation, shock wave, the electric field on the sterilization are approximately30.8±4.8%、36.1±5.5、12.7±1.8%respectively, thus the proportion of the active free radicals on the sterilization is calculated, and the value is about20.4±2.5%。Secondly, a large discharge device with4m-long pipe is designed, and the type of the electrode is rod-rod. The peak pressure and propagation characteristic of shock wave are measured using pressure sensor. The propagation speed of shock wave underwater is1500m/s. When the electrode gap is constant, the shock waves increase with the increasing of voltage. the shock wave intensity is calculated by averaging many values of the experiment, and the experience formula is Pr=2.56E·e-0.4831r. In the experiment, when the voltage of discharging remains constant, and the electrode gap increases from3mm to7mm, the shock wave peak increases first and then decrease. The pressure of the shock wave increases with the increasing of electrode gap, when the current peak is under the same conditions. The reason is mainly that the electrical breakdown time of plasma channel depends on the equivalent resistance of the channels and the current peak. When the electrode gap increases, the equivalent resistance of the channels is also increases. Therefore, if the current is constant, the power of plasma channel increases with the increasing of the electrode spacing. Pulse energy has a linear relation with the peak pressure of shock wave; the peak pressure of shock wave is increased when the discharge power is greater.Thirdly, discharge in liquid can effective use the advantage of shock wave and the effective diffusion of ultraviolet rays and free radicals, and the energy is used effectively. A single discharge can be effective in a wide range. The fouling organism Mytilus edulis Linnaeus which is in the pipe over a long distance is killed using the shock wave and the UV produced by the high-voltage pulse discharge in liquid, and the adhesion and mortality rates of Mytilus edulis Linnaeus were investigated. At the same time, the biological activity of Mytilus edulis Linnaeus was also monitored. The feasibility of treatment of fouling organisms using high voltage pulse discharge in liquid was also studied. The results showed that increasing the pulse voltage peak, increasing the total intput energy, low frequency and long time, many times dealing and short time had good effect on the eliminating of Mytilus edulis Linnaeus. At the same time, the discharge process can effectively reduce the biological activity of Mytilus edulis. In every group of experiment, the activity of enzyme system SOD in Mytilus edulis Linnaeus is negatively correlated with the concentration of MDA, and the activity of CAT is negatively correlated with the concentration of H2O2, and the trend of SOD is similar to that of CAT. It is proved that the high-voltage pulse discharge in liquid can be quickly and effectively on the remove of Mytilus edulis Linnaeus in the long-distance pipe.