Mass and heat transfer at the outer surface of helical coils under single and two phase flow

Intensification of the Rate of Diffusion-controlled Electrochemical and Catalytic Reactions at a Helical Coil by a Fixed Bed Turbulence Promoter

“…To demonstrate the role of bed packing particle in enhancing the rate of mass transfer at the imbedded helical coil, a comparison of the present data with the data obtained at helical coil under single-phase flow in a cylindrical vessel without packing by Abdel-Aziz et al 14…”

“…The advantages of using helical coils as a heat exchanger/reactor over straight tubes are: (i) helical coils are more compact and hence have a higher area per unit volume, which gives rise to high-space time yield, (ii) the rate of heat transfer inside helical coils is much higher than in straight tubes 12 . Although the heat and mass transfer behavior of the outer and inner sides of helical coils was studied under different hydrodynamic conditions [12][13][14][15][16] , no previous studies have been reported on the use of inert fixed beds to enhance the rate of heat or mass transfer at the coil outer surface. The mass transfer behavior of the outer surface of a helical tube was studied using the electrochemical technique, which involves measuring the limiting current of the cathodic reduction of K 3 Fe(CN) 6 in a large excess of NaOH as a supporting electrolyte 17 .…”

Intensification of the Rate of Heat and Liquid‐Solid Mass Transfer at the Wall of a Bubble‐Column Reactor by Turbulence Promoters

“…Also, Kumar et al 13 used a coaxially placed string of spheres, while Vijay and Ramesh 14 employed a string of cones to enhance the rate of mass transfer between the bubble column wall and the solution bulk. In the area of heat transfer, the performance of internal heat exchangers such as vertical tube bundles 15, horizontal bundles of tubes 16, 17, and helical coils 15, 18, 19 was studied. The above internal heat exchangers can be used with a cooling jacket for faster removal of heat in case of highly exothermic reactions that need rapid cooling such as immobilized cell biochemical reactions which involve heat‐sensitive materials, and Fischer‐Tropsch synthesis where it is essential to maintain the temperature within a narrow fluctuation since it significantly affects reaction selectivity, throughput of the desired product, catalyst activity, and reactor safety 20.…”

The Effect of Using Baffles on the Rate of Mass Transfer of a Cylindrical Stirred Tank Reactor

“…The trend has lately been to utilize the heat produced from reactors used in exothermic reactions where reactants, materials or catalysts may be sensitive to unregulated temperatures. The task of mixing is to homogenize the different materials used and to improve heat transfer, mass transfer and the rate of chemical reactions between the various species and phases [1]. Mechanical stirring using a revolving impeller, jet mixing, and static mixing provide different mixing methods used in engineering work.…”