Experimental investigation on pair bubble columns under high voltage DC electric filed

Abstract

The behavior of a pair bubble column rising in an insulating liquid in the presence of a high voltage electric field was investigated. The purpose of this study was to investigate the bubble column flow regime and the possibility of transferring it without changing the basic parameters of the bubble column. The use of the electric field was the main factor in applying this change to the bubble column. The results show that the employment of an external electric field significantly changes the size, detachment frequency and the pattern of the bubble column. With an increase in electrical potential, the bubble growth time and detachment volume (bubble size) decline continuously due to electrical stress on the bubble surface. Moreover, at sufficiently high electric potential, the electric field intensifies the bubble collision and coalescence, which subsequently leads to more enhancements of the heat and mass transfer in the bubble column reactor. The use of the electric field increased the bubble detachment for Db=1.12mm by 250%, and for the largest bubble in range Db=3.32mm, this increase was about 80%.