bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. high mixing that result in high heat and mass transfer rates are amongst their advantages. heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

In this work, the characteristics of flow and heat transfer of a fluid containing nano particles of aluminum oxide with the water volume fraction (0.1-0.2-0.3)(V/V) percent of the reports. The overall heat transfer coefficient, heat transfer and the average heat transfer fluid containing nano water - aluminum oxide in a horizontal double pipe counter flow heat exchanger under turbulent flow con...

the effect of γ-al2o3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-al2o3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. since the properties of γ-al2o3-water nanofluids were variable, they were ...

Pulsating heat pipe is an efficient heat exchange device which is being used for cooling and heating recovery. In the present work, we made a closed-loop pulsating heat pipe with six U-turns and we used water in our system. Moreover the use of water-Fe3O4 nanofluid was studied with two different filling ratios 40% and 50% and 1% mass concentration. At the end we calculated heat resistance and h...

Pulsating heat pipe is an efficient heat exchange device which is being used for cooling and heating recovery. In the present work, we made a closed-loop pulsating heat pipe with six U-turns and we used water in our system. Moreover the use of water-Fe3O4 nanofluid was studied with two different filling ratios 40% and 50% and 1% mass concentration. At the end we calculated heat resistance and h...

natural convection heat transfer from a tube bundle in the indirect water bath heaters is investigated. a computer-code is used for the solution of the governing equations of mass, momentum and energy transfer based on the simple-c algorithm. simulations are carried out for the gas pressure station heater of kermanshah city with various tube bundle arrangements. in order to validate the numeric...

introduction drying foods, fruits and vegetables is a suitable method to reduce post-harvest losses of the crops. drying is considered as a simultaneous heat and mass transfer process. various physical, chemical and nutritional changes occur during drying of foods and are affected by a number of internal and external heat and mass transfer parameters. external parameters may include temperature...

thermal conductivity is an important property of juices in the prediction of heat- and mass-transfer coefficients and in the design of heat- and mass-transfer equipment for the fruit juice industry. an artificial neural network (ann) was developed to predict thermal conductivity of pear juice. temperature and concentration were input variables. thermal conductivity of juices was outputs. the op...

one of the cooling systems that has received considerable attentions in recent years is the adsorption chiller, which works based on the adsorption and desorption of a working fluid in a solid porous bed. different parameters such as fin height directly affect the bed heat and mass transfer processes, and therefore, the performance of the adsorption chillers. in the present study a numerical mo...

The paper aims at investigating the effects of chemical reaction and thermal radiation on the steady two-dimensional laminar flow of viscous incompressible electrically conducting micropolar fluid past a stretching surface embedded in a non-Darcian porous medium. The radiative heat flux is assumed to follow Rosseland approximation. The governing equations of momentum, angular momentum, energy, ...