Study On Flow Characteristics Of Plate And Frame Electrolyzer

Plate and frame electrolyzer is widely used in electrochemical industry because of its advantages:compact structures, high volume current density(high space and time production rate), low tank voltage and so on. For example, the ion membrane chlorine alkali synthetic industry, adiponitrile electrosynthesis and indirect electro-oxidation synthetic vitamin K3 in the organic electrosynthetic industry, indirect electro-oxidation synthetic vitamin K3 all chosed plate and frame electrolyzers. As was well known, flowing law in industry reactor was one of important factors on chemical reactions. Therefore, quantitative research flowing law and influence of flowing law on reaction were very necessary in industry reactor and so few reports on such studies.Two kinds of the different structural plate and frame electrolyzers (A-type and B-type) that were self—designed and made through referring to the domestic and foreign literature and the massive experiments.The flow model parameters were obtained from determining the fluid resident time distributions and the fluid flowing law was quantitative described in reactor. The results showed that A-type reactor approached to ideal mixing and B-type reactor approached to plug—flow .And influence rules of flowing on producing Cr(Ⅵ) from Cr(Ⅲ) by electro-oxidation and electrochemical reduction of nitrobenzene to ρ-aminophenol were studied separately in these two kinds of reactors. Conclusions as follow: First, regarding A-type plate and frame electrolyzer:1 .The model parameters N of completely mixed tanks-in-series reactor were in the vicinity of 1 in determination flow rate range.2. The flow rate oversized or small all caused flow pattern deviating from grade of ideal mixing to enlarge, which flow rate most approached ideal mixing in 270L/h.3.When flow rate Q>300L/h, with flow rate increasing , the difference value increased between mean residence time x and V/Q(V for reactors effective size) and τ>V/Q, indicating the short-circuiting rate increased in reactor; when flow rate Q≤300L/h, with flow rate decreasing, the difference value increased between x and V/Q and τ