Experimental Analysis of Thermal Conductivity of Carboxymethylcellulose Sodium Salt Aqueous Solutions

Advancing the chemical engineering fundamentals

Rheology (T2-4)

Prof Lubomira Broniarz-Press
Poznan University of Technology
Dpt. of Chemical Engineering and Equipment
pl. M. Sklodowskiej-Curie 2
PL 60-965 Poznan
Poland

MSc Karol Pralat
Higher Vocational State School of President Stanislaw Wojciechowski
Polytechnic Institute
Czestochowska 140
62-800 Kalisz
Poland

Dr Kazimierz Wojciech Pyc
Lodz University of Technology
Dpt. of Process Equipment
Wolczanska 175
PL 90-924 Lodz
Poland

Keywords: heat transfer coefficient, power-law fluids, shear effect

Many important industrial fluids, which are non-Newtonian or rheologically complex in their flow characteristics are often used in the chemical processes and food industries, as well as in many other practical applications. As no other literature data being available the previous papers on heat transfer coefficient in non-Newtonian fluids heat transfer in various constructional solutions were based on the thermal conductivity of the clear solvent. It was a very rough approximation that existed long. In our opinion, when the possibility of the both, temperature and shear conditions effects existed in a non-Newtonian fluid, the examination of the thermal conductivity in tube flowing system is required and necessary one for the design practice.
In the present paper the results of the experimental studies directed on the correlation of the non-Newtonian fluids rheological behavior and thermal conductivity taking into account shear rate effect, have been presented. The liquids tested were water, glycerol and petrol, as Newtonian fluids, and carboxymethylcellulose sodium salt (of the molecular mass M = 250,000, Aldrich Comp.) aqueous solutions as non-Newtonian fluids (of the polyelectrolyte concentrations in a solutions ranged from 1000 to 5000 ppm). Experiments were performed at temperatures changed in the range from 299 K to 315 K. The shear rate range studied was 0    600 [s-1]. It was confirmed that the thermal conductivity  of Newtonian liquids at T = const is independent of shear rate. For the non-Newtonian aqueous solutions studied the relation of  = f(T, ) is evident and should be taken into account in all design practices. The thermal conductivity increases linearly with shear rate increase. The maximal effect was observed at temperature 315 K for the carboxymethylcellulose sodium salt solution of the concentration of 1000 ppm.

See the full pdf manuscript of the abstract.

Presented Thursday 20, 15:20 to 15:40, in session Rheology (T2-4).