Effect of distance between impeller blade tip and surface on mass transfer to a local electrode in a stirred vessel in a wide range of Sc number

YAPICI S., Altay I.

INDIAN CHEMICAL ENGINEER, vol.64, no.5, pp.576-593, 2022 (ESCI) identifier

  • Publication Type: Article / Article
  • Volume: 64 Issue: 5
  • Publication Date: 2022
  • Doi Number: 10.1080/00194506.2022.2059020
  • Journal Name: INDIAN CHEMICAL ENGINEER
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.576-593
  • Keywords: electrochemical limiting current technique, convective transfer, mass transfer, stirred vessel
  • Inonu University Affiliated: Yes

Abstract

Stirred vessels are encountered in a wide scale of applications from bench to industrial processes, and the knowledge of the heat/mass transfer rates in these vessels is required for their design, operation and control. This work submits an investigation on the mass transfer to a small circular surface immersed in a stirred vessel in the parameter ranges of 267 < Re <9437, 1473 < Sc <61,422, and 0.022 < x/d(k) < 0.22 for the distance between the impeller blade tip and the transfer surface. The Reynolds number was based on the impeller diameter. The electrochemical limiting diffusion current technique having a potassium ferri-/ferrocyanide system was applied for mass transfer coefficient measurements. Aqueous glycerine solutions were prepared to attain a wide range of Sc numbers. The rate of mass transfer is enhanced with increasing rotation rate, decreasing blade tip-to-electrode surface distance, and decreasing glycerine concentration. The experimental data were well correlated by the relation Sh = 8.517Re(0.473)Sc(0)(.402)(x/d(k))(-0.042).