The disposal of Waste Activated Sludge is a major problem. The paper presents several disposal routes. The ultimate steps in these routes are indirect drying and subsequent incineration. Although the design of the indirect dryers is straightforward from a required heat input, operating temperature difference between sludge bed and heating medium and the heat transfer coefficient, this coefficie...

the vehicle braking system is considered to be one of the most fundamental safety-critical systems in modern vehicles, as its main purpose is to stop or decelerate the vehicle. the frictional heat generated during braking application can cause numerous negative effects on the brake assembly, such as brake fade, premature wear, thermal cracks and disc thickness variation. in the past, surface ro...

helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. in this kind of heat exchangers, flowand heat transfer are complicated. this paper reports a numerical investigation of theinfluence of different parameters such as coil...

In present study, the two phase flow boiling heat transfer coefficient and pressure drop of R410A, R32 and R290 in microchannels are demonstrated. The experimental data were conducted in horizontal stainless steel tubes with the inner diameter of 0.3 mm and 1.5 mm. The testing conditions were performed with the mass fluxes range from 200 to 500 kg/m2s, the heat fluxes from 10 to 20 kW/m2, the s...

The potential of nanofluids for the improvement of heat transfer coefficient in various heat exchangeequipment has been considered and studied as a major application during recent decades. In this research,heat transfer coefficient of ZnO, TiO2 and ZnO/TiO2 nanofluids in a shell and tube heat exchanger has beenstudied experimentally. ZnO nanoparticle was synthesized through pre...

In order to examine the laminar convective heat transfer of nanofluid, experiments carried out using silver-oil nanofluid in a concentric annulus with outer constant heat flux as boundary condition. Silver-oil nanofluid prepared by Electrical Explosion of Wire technique and observed no nanoparticles agglomeration during nanofluid preparation process and carried out experiments. The average size...

Nanofluids, stabilized suspensions of nanoparticles typically < 100 nm in conventional fluids, are evolving as potential enhanced heat transfer fluids due to their better thermal conductivity, increase in single phase heat transfer coefficient and significant increase in critical boiling heat flux. In the present paper, we investigate the overall thermal resistance of a closed two-phase thermos...

On the basis of the exergy analysis, a performance optimization is carried out for a generalized irreversible refrigerator model, which takes into account the heat resistance, heat leakage and internal irreversibility losses. A new ecological criterion, named coefficient of performance of exergy (COPE), defined as the dimensionless ratio of the exergy output rate to the exergy loss rate, is pro...

Three-Phase Fluidized Beds have found an important place in processing technology as Reactors. Gas-Liquid-Solid fluidization is considered in the present paper as operating bed of fluidized solid particles simultaneously with co-current upward flow of a continuous liquid phase and a gaseous phase dispersed in the form of bubbles. In the present study, the experimental work of the author on heat...