Abstract:
In order to study the charging characteristics and electrostatic field characteristics of the steam spray, we experimentally investigated three kinds of charging methods, namely, corona charging, induction charging, and contact charging. To study the effects of charging voltage, inter-electrode distance, and electrode installation position on the charge-to-mass ratio and electrostatic field of the spray, we selected 3 electrode structures, namely, needle-plate electrode, ring electrode, and needle-ring electrode, as the research objects. With the increase of the charging voltage, for the needle-plate electrode, the droplets are subjected to the combined action of corona discharge and ion wind-promoted evaporation, thus the charge-to-mass ratio of the spray first increases and then decreases. For the ring electrode, the spray charge-to-mass ratio first increases and then decreases. For the needle-to-ring electrode, the spray charge-to-mass ratio keeps increasing. Reducing the inter-electrode distance and increasing the distance between the electrode and the nozzle can increase the charge-to-mass ratio of the spray. When the charging voltage is negative, the charging efficiency is higher. Under the same charging voltage, the spray charge-to-mass ratio and electrostatic field generated by contact charging are higher than those of the other two charging methods, and the maximum charge-to-mass ratio is 1.61 mC/kg. The spray electrostatic field is generated by the charged droplets and the ions that migrate around after the droplets evaporate.