Heat Transfer in the Non-reacting Zone of a Cement Rotary Kiln

1996 ◽  
Vol 118 (1) ◽  
pp. 169-172 ◽  
Author(s):  
P. S. Ghoshdastidar ◽  
V. K. Anandan Unni
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Rotary Kiln ◽  
Gas Flow ◽  
Transfer Model ◽  
Temperature Profiles ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Steady State Heat ◽  
Steady State Heat Transfer

This paper presents a steady-state heat transfer model for a rotary kiln used for drying and preheating of wet solids with application to the non-reacting zone of a cement rotary kiln. A detailed parametric study indicates that the influence of the controlling parameters such as percent water content (with respect to dry solids), solids flow rate, gas flow rate, kiln inclination angle and the rotational speed of the kiln on the axial solids and gas temperature profiles and the total predicted kiln length is appreciable.

Computer Simulation of Drying of Food Products With Superheated Steam in a Rotary Kiln

2010 ◽  
Author(s):  
Koustubh Sinhal ◽  
P. S. Ghoshdastidar ◽  
Bhaskar Dasgupta
Keyword(s):  
Heat Transfer ◽  
Computer Simulation ◽  
Flow Rate ◽  
Rotary Kiln ◽  
Rotational Speed ◽  
Gas Flow ◽  
Superheated Steam ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Refractory Wall

The present work reports a computer simulation study of heat transfer in a rotary kiln used for drying and preheating food products such as fruits and vegetables with superheated steam at 1 bar. The heat transfer model includes radiation exchange among the superheated steam, refractory wall and the solid surface, conduction in the refractory wall, and the mass and energy balances of the steam and solids. Finite-difference techniques are used, and the steady state thermal conditions are assumed. The false transient approach is used to solve the wall conduction equation. The solution is initiated at the inlet of the kiln, and proceeds to the exit. The output data consist of distributions of the refractory wall temperature, solid temperature, steam temperature, and the total kiln length. The inlet of the kiln is the outlet of the gas (superheated steam), since the gas flow is countercurrent to the solid. Thus, for a fixed solid and gas temperature at the kiln inlet, the program predicts the inlet temperature of the gas (i.e. at the kiln exit) in order to achieve the specified exit temperature. In the absence of experimental results for food drying in a rotary kiln, the present model has been satisfactorily validated against numerical results of Sass [1] for drying of wet iron ore in a rotary kiln. The results are presented for drying of apple and carrot pieces. A detailed parametric study indicates that the influence of controlling parameters such as percent water content (with respect to dry solids), solids flow rate, gas flow rate, kiln inclination angle and the rotational speed of the kiln on the axial solids and gas temperature profiles and the total predicted kiln length is appreciable. The study reveals that a good design of a rotary kiln requires medium gas flow rate, small angle of inclination and low rotational speed of the kiln.

Computer Simulation of Drying of Food Products With Superheated Steam in a Rotary Kiln

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Koustubh Sinhal ◽  
P. S. Ghoshdastidar ◽  
Bhaskar Dasgupta
Keyword(s):  
Heat Transfer ◽  
Computer Simulation ◽  
Flow Rate ◽  
Rotary Kiln ◽  
Gas Flow ◽  
Superheated Steam ◽  
Food Products ◽  
Gas Temperature ◽  
Refractory Wall ◽  
Solid Temperature

The present work reports a computer simulation study of heat transfer in a rotary kiln used for drying and preheating food products such as fruits and vegetables with superheated steam at 1 bar. The heat transfer model includes radiation exchange among the superheated steam, refractory wall and the solid surface, conduction in the refractory wall, and the mass and energy balances of the steam and solids. The gas convection is also considered. Finite-difference techniques are used, and the steady state thermal conditions are assumed. The false transient approach is used to solve the wall conduction equation. The solution is initiated at the inlet of the kiln and proceeds to the exit. The output data consist of distributions of the refractory wall temperature, solid temperature, steam temperature, and the total kiln length. The inlet of the kiln is the outlet of the gas (superheated steam), since the gas flow is countercurrent to the solid. Thus, for a fixed solid and gas temperature at the kiln inlet, the program predicts the inlet temperature of the gas (i.e., at the kiln exit) in order to achieve the specified exit temperature of the gas. In the absence of experimental results for food drying in a rotary kiln, the present model has been satisfactorily validated against numerical results of Sass (1967, “Simulation of the Heat-Transfer Phenomena in a Rotary Kiln,” Ind. Eng. Chem. Process Des. Dev., 6(4), pp. 532–535) and limited measured gas temperature as reported by Sass (1967, “Simulation of the Heat-Transfer Phenomena in a Rotary Kiln,” Ind. Eng. Chem. Process Des. Dev., 6(4), pp. 532–535) for drying of wet iron ore in a rotary kiln. The results are presented for drying of apple and carrot pieces. A detailed parametric study indicates that the influence of controlling parameters such as percent water content (with respect to dry solids), solids flow rate, gas flow rate, kiln inclination angle, and the rotational speed of the kiln on the axial solids and gas temperature profiles and the total predicted kiln length is appreciable. The effects of inlet solid temperature and exit gas temperature on the predicted kiln length for carrot drying are also shown in this paper.

Wpływ warunków środowiskowych i instalacyjnych na proces wymiany ciepła w wybranych przemysłowych gazomierzach miechowych

Nafta-Gaz ◽  
2020 ◽  
Vol 76 (11) ◽  
pp. 828-836
Author(s):  
Adrian Dudek ◽  
Keyword(s):  
Heat Exchange ◽  
Ambient Temperature ◽  
Flow Rate ◽  
Gas Flow ◽  
Exchange Process ◽  
Test Results ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Heat Exchange Process ◽  
The Relationship

Since 2016, Oil and Gas Institute – National Research Institute (INiG – PIB) has been conducting new research to determine the relationship between ambient temperature and gas temperature in industrial diaphragm gas meters during the measurement, and to develop new recommendations for billing systems using industrial diaphragm gas meters with a throughput of until 25 m3/h. In the first stage, work was carried out, in which the obtained test results confirmed that the heat exchange process in an industrial diaphragm gas meter depends on the ambient temperature, the gas temperature at the inlet to the gas meter, the flow rate of the gas flowing, as well as the casing surface and the gas volume of the gas meter. In the next stage, work was carried out to determine the relationship between ambient temperature and gas temperature at the industrial diaphragm gas meter connection during the measurement. The obtained results undermined the thesis, which indicated that the gas inlet temperature is equal to the gas temperature at the depth of the gas network. In the last stage, work was carried out to determine the course of changes in gas temperature in industrial diaphragm gas meters as a function of ambient temperature and cyclical changes of the gas flow rate, which were to reflect the work of gas meters installed at customers’ premises. The analysis of the obtained test results once again showed a strong dependence of the gas temperature inside industrial diaphragm gas meters on the ambient temperature, but also on the flow rate of gas. The obtained results of laboratory tests will be used to carry out a thermodynamic description of the heat exchange process in an industrial diaphragm gas meter, which would allow the determination of the gas billing temperature as a function of the ambient temperature, the temperature of the inflowing gas and the gas flow rate. The calculated gas temperature values could be used to determine the temperature correction factors applicable when settling gas consumers billed on the basis of measurement with the use of industrial diaphragm gas meters.

Determining Gas Flow Rate and Formation Thermal Conductivity from Pressure and Temperature Profiles in Vertical Well

2012 ◽  
Author(s):  
Emile Eli Barrett ◽  
Imran Abbasy ◽  
Chii Rong Wu ◽  
Zhenjiang You ◽  
Pavel G. Bedrikovetsky
Keyword(s):  
Thermal Conductivity ◽  
Flow Rate ◽  
Gas Flow ◽  
Temperature Profiles ◽  
Gas Flow Rate ◽  
Vertical Well

scholarly journals Effects of Gas Flow on Spectral Properties of Plasma Jet Induced by Microwave

2018 ◽  
Vol 15 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Plasma Jet ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
Jet Length ◽  
Maximum Value

In this paper, a construction microwave induced plasma jet(MIPJ) system was used to produce a non-thermal plasma jet at atmospheric pressure, at standard frequency of 2.45 GHz and microwave power of 800 W. The working gas Argon (Ar) was supplied to flow through the torch with adjustable flow rate using flow meter regulator. The influence of the MIPJ parameters such as applied voltage and argon gas flow rate on macroscopic microwave plasma parameters were studied. The macroscopic parameters results show increasing of microwave plasma jet length with increasing of applied voltage, argon gas flow rate where the plasma jet length exceed 12 cm as maximum value. While the increasing of argon gas flow rate will cause increasing into the argon gas temperature, where argon gas temperature the exceed 350 ? as maximum value and study the effect of gas flow rate on the optical properties

Boundary Design of Reflection Properties of a Steady-State Complex Heat Transfer Model

2016 ◽  
Vol 685 ◽  
pp. 90-93
Author(s):  
Alexander Yu. Chebotarev ◽  
Andrey E. Kovtanyuk
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Control Problem ◽  
Radiation Effects ◽  
Heat Transfer Model ◽  
Heat Radiation ◽  
Transfer Model ◽  
Multiplicative Control ◽  
Steady State Heat ◽  
Steady State Heat Transfer

A boundary multiplicative control problem for a nonlinear steady-state heat transfer model accounting for heat radiation effects is considered. The aim of control consists in obtaining a prescribed temperature or radiative intensity distributions in a part of the model domain by controlling the boundary reflectivity. The solvability of this control problem is proved, and optimality conditions are derived.

Multiscale Modeling of Heat Transfer in a Thermal Sensing Atomic Force Microscope

2008 ◽  
Author(s):  
Nathan D. Masters ◽  
Wenjing Ye
Keyword(s):  
Heat Transfer ◽  
Atomic Force Microscope ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Flow Regimes ◽  
Atomic Force ◽  
Thermal Sensing ◽  
Scan Data ◽  
Steady State Heat ◽  
Steady State Heat Transfer

Thermal Sensing Atomic Force Microscope (TSAFM) systems utilize heat transfer in continuum and low-speed rarefied gas flow regimes to perform topological surface scans. Spanning flow regimes complicates the modeling required to analyze scan data. In this paper we present a hybrid Octant Flux Splitting IP-DSMC/BEM model of the steady state heat transfer from a TSFAM cantilever and compare with the uncorrected continuum solution as well as a macro model developed for this problem.

scholarly journals Exergy Analysis of Waste Incineration Plant: Flue Gas Recirculation and Process Optimization

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 29
Author(s):  
Giorgio Vilardi ◽  
Nicola Verdone
Keyword(s):  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Exergy Analysis ◽  
Waste Incineration ◽  
Exergy Efficiency ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

Simulations of two incineration processes, with and without flue gas recirculation, have been carried out performing an exergy analysis to investigate the most critical equipment unit in terms of second-law efficiency. Flue gas from the economizer outlet is employed to partially replace secondary combustion air to reduce, at the same time, incinerator temperature and oxygen concentration. Conversely, in the proposed configuration, the recirculated flue gas flow rate is used to control incinerator temperature, while the air flow rate is used to control the oxygen content of the fumes, leaving the incinerator as close to 6% as possible—i.e., the minimum allowed for existing plants to ensure completion of the combustion reactions and according to environmental regulations—and determines the corresponding minimum flue gas flow rate. The flue gas recirculation guarantees a larger level of energy recovery (up to +3%) and, at the same time, lower investment costs for the lower flow rate of fumes actually emitted if compared to the plant configuration without flue gas recirculation. Various operating parameters were varied (incinerator’s effluent gas temperature, air flowrate and flue gas recirculation flowrate) to investigate their influence on process exergy efficiency. Exergy analysis allowed the individuation of the equipment units characterized by larger exergy destruction and demonstrated that the flue gas recirculation led to an overall process exergy efficiency increase of about 3%.

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