heat and mass transfer in reactors

... fluid flow,heat and mass transfer over disks rotating in a resting, rotating or radially accelerat-ing fluid; unsteady conjugate heat transfer of a rotating disk (Fig 1.1a); disk cooling by means ... 8.3 Transitional and Turbulent Flows at High Prandtl and Schmidt Numbers 208 8.4 An Integral Method for Modelling Heat and Mass Transfer in Turbulent Flow for the Prandtl and Schmidt Numbers ... convective heat andmass transfer in rotating-disk systems Such systems are widespread in scientificand engineering applications As examples from the practical area, one can mentiongas turbine and computer

Ngày tải lên: 14/05/2018, 13:50

... the injection case Heat transfer profiles significantly increase across the whole domain of the disks for suction and injection cases as shown in Figs 4 and 5 Injection increases the mass transfer ... expanding disks (α > 0), heat transfer rate and shear stress at the lower disk escalate with M and Re, whereas heat transfer rate falls with ϕ and Tr Moreover, mass transfer rate de-creased in ... seen for mass transfer rate Figures 2, 3, 4, 5, 6, and 7 depict the behavior of Re on velocity, heat, and mass transfer profiles In the case of suction, increasing behavior is observed in the center

Ngày tải lên: 04/12/2022, 10:34

... form and their radii were estimated according to [12]: 1 n m In the above expression, rA and rB are either of the ionic radius, or of the covalence radius according to the existing binding types ... Trang 14 Transfer equation 4.1 Determination of the stoichiometric coefficient To simplify the writing and calculation of the mass transfer equation at the interface, a dimensionless ... formed by basalt, and its composition is given in table 1 At high temperatures (T > 1700K), in the presence of oxygen and argon, the following species are preserved in the model: - In the vapor

Ngày tải lên: 19/06/2014, 10:20

... flow 2 Instability in electrochemical nucleation 2.1 The first instability occurring in 2D nucleation Assuming that a minute 2D nucleus is accidentally formed in the diffuse layer belonging to ... time, rate-determining step is changed from electron-transfer in the electric double layer to mass transfer in the diffusion layer, and expressed by the concentration overpotential; instability arises ... t Since both fluctuations are in the Boltzmann equilibrium in the diffuse layer, from Eqs (4b) and (7b), the following relationship between a m L and L a is obtained   * 0, On the other hand,

Ngày tải lên: 19/06/2014, 10:20

... thickness and thermal conductivity of a single pane window and the air space of a double pane window Representative winter surface temperatures of single pane and air space FIND: Heat loss through single ... laminates, will it indicate heat fluxes that are systematically high or low? Trang 13PROBLEM 1.13 KNOWN: Hand experiencing convection heat transfer with moving air and water FIND: Determine ... caution, and only for surface and surrounding Trang 30PROBLEM 1.30KNOWN: Chip width, temperature, and heat loss by convection in air Chip emissivity and temperature of large surroundings. FIND: Increase

Ngày tải lên: 08/08/2014, 17:20

... competing effects of hrad and A3′ = ( 1 2 r π 3) Because the initial decay in T3 = Ts,o withincreasing r3, and hence, the reduction in hrad, is more pronounced than the increase in A′3, R′rad increases ... adjoining fluidconditions. FIND: (a) Critical insulation radius, (b) Heat transfer per unit length for bare rod and for insulation at critical radius, (c) Insulation thickness needed for 25% heat ... T∞ Thermal contact resistance between heater and tube wall and wall inner surface temperature. FIND: Heater power per unit length required to maintain a heater temperature of 25 °C. SCHEMATIC:

Ngày tải lên: 08/08/2014, 17:20

... constant heat flux oq ′′ = 2000 W/m2 See also Problem 2.43.FIND: (a) Using spatial and time increments of ∆x = 5 mm and ∆t = 20s, compute and plot the temperature distributions in the wall for the initial ... (a) Using spatial and time increments of ∆x = 4 mm and ∆t = 1s, compute and plot the temperature distributions in the wall for the initial condition, the steady-state condition, and two intermediate ... 38Using linear interpolation between rows 7 and 8, we obtain T(L/2, 230s) = T5≈ 100°C <(b) Using the option concerning Finite-Difference Equations for One-Dimensional Transient Conduction in

Ngày tải lên: 08/08/2014, 17:20

... would involvedetermining NuL for the full range of elapsed time (rather than at two selected times) and using a fittingroutine to determine values for C and m Trang 20 Cylinder diameter and surface ... greater heat transfer enhancement due to increasing the diameter Trang 28PROBLEM 7.46KNOWN: Pin fin installed on a surface with prescribed heat rate and temperature. FIND: (a) Maximum heat removal ... associated with increasing V which increases the convection coefficient and the total heat rate Although the convection coefficient decreases with increasing D, theincrease in the total heat transfer

Ngày tải lên: 08/08/2014, 17:20

... Since hh, and hence Uh, increases with m , q, and hence, Th c,o, increases with increasing m , as well ash with increasing Th,i Although q increases with m , the proportionality is not linear ... water-to-water heat exchanger as shown in the schematic includingthe flow rate, and inlet and outlet temperatures FIND: (a) Design a heat exchanger to meet the specifications; that is, size the heat exchanger, ... tube heat exchanger of Example 11.1; maintaining the outlet oil temperature of 60°C, but with variable rate of cooling water, all other conditions remaining the same FIND: (a) Calculate and plot

Ngày tải lên: 08/08/2014, 17:20

... Jean-Michel Hugo and Frédéric Topin Heat and Mass Transfer in Matrices of Hygroscopic Wheels C R Ruivo, J J Costa and A R Figueiredo 187 219 245 Treatment of Rising Damp in Historical Buildings Ana ... dampening of the RH variation in a room and its hygroscopicity level, which is mainly dependant on the surface finishing materials and furnishing According to the principle, a hygroscopic inertia index ... epoxy paint and the four edges were covered with aluminium tape, allowing vapour transfer only in the main face The Evaluation of Hygroscopic Inertia 31 Fig Mass variation stable cycle in MBV...

Ngày tải lên: 31/03/2014, 16:20

... electronic cooling, ceramic processing, and overland flow during rainfall In thermal insulation engineering, an appreciable insulating effect is derived by placing porous material in the gap between ... number in x and y directions in inlet int interface line in reactor interface interface value l east, west, north, and south point of control volume n north w west p control volume center point; ... to heat and mass transfer; 22 Chapter Introduction To implement the Ochoa-Tapia and Whitaker’s stress jump conditions for the flow, heat and mass transfer in porous/fluid coupled domains, and...

Ngày tải lên: 12/09/2015, 21:13

... kinetic models must include detailed transport phenomena since char gasification is a process controlled by both chemical reactions and internal and external mass and heat transfer processes Indeed, ... adopted and the ability of the developed model in predicting the thermo-chemistry of char gasification and the heat and mass transfer phenomena within the downdraft reactor Simulations In this ... of the initial size at the reactor inlet (shrinking caused by the flaming-pyrolysis step) [13] - Conversion of bio-char particles in the reduction zone is achieved following the shrinking unreacted...

Ngày tải lên: 01/08/2016, 09:31

... Thermal and Mass Diffusion Effects 10.15.1 Conservation Equations and Scaling Analysis 10.15.2 Heat and Mass Transfer Analogy 10.16 Solutions for Natural Convection Caused by Combined Thermal and Mass ... Notation w X Y y Velocity in z direction in Cartesian coordinates, in θ direction in cylindrical coordinates, or in ϕ direction in spherical coordinates (m/s); work per unit mass (W/kg) Mole fraction ... convection heat and mass transfer all the more challenging Perhaps the two biggest challenges for an instructor of a graduate-level course in convection are defining a scope for the course and striking...

Ngày tải lên: 30/03/2014, 19:20

... convection and the superposition of free and forced convection Finally an introduction to heat transfer in compressible fluids is presented In the fourth chapter the heat and mass transfer in condensation ... chapter, which contains the basic concepts and fundamental laws of heat and mass transfer The student obtains an overview of the different modes of heat and mass transfer, and learns at an early ... solved using the balance equations and the heat and mass transfer coefficients, without requiring too deep a knowledge of the theory of heat and mass transfer Such problems are dealt with in the...

Ngày tải lên: 02/04/2014, 15:27

... 2.10 2.13 Find the difference in pressure between tanks A and B, if d1 ¼ ft, d2 ¼ in. , d3 ¼ 2.4 in. , and d4 ¼ in Find the pressure at point A Air B b d4 45° H2O in A in Water temp = 150°F in Kerosene ... Engineering Department at Oregon State University with expertise in biochemical engineering He has had a significant in uence on this edition’s sections on mass transfer, both in the text and in ... Chapter Introduction to Momentum Transfer Of specific interest in momentum transfer is the description of the point-to-point variation in the pressure Denoting the directions east and north in Figure...

Ngày tải lên: 02/04/2014, 15:51

... thickness and thermal conductivity of a single pane window and the air space of a double pane window Representative winter surface temperatures of single pane and air space FIND: Heat loss through single ... thickness and thermal conductivity of a single pane window and the air space of a double pane window Representative winter surface temperatures of single pane and air space FIND: Heat loss through single ... KNOWN: Speed, width, thickness and initial and final temperatures of 304 stainless steel in an annealing process Dimensions of annealing oven and temperature, emissivity and convection coefficient...

Ngày tải lên: 02/04/2014, 15:52

... involvement of mass flow and mixing This is the mode of heat transfer through solid barriers and is encountered extensively in heat transfer equipment design as well as in heating and cooling of various ... adding the insulation, the surface temperature is reduced to 160°C and again the heat loss is mainly due to radiation, the surroundings in both cases being at 25°C Determine the change in heat transfer ... HEAT AND MASS TRANSFER A sphere of 0.5m diameter containing hot fluid has an insulation of 0.1m thickness Before adding the insulation, the surface temperature was 260°C and heat loss was mainly...

Ngày tải lên: 08/04/2014, 10:55

... on the internal and external active surface The Heat and Mass Transfer – Modeling and Simulation modeling routines were implemented in Fortran 90 and the equations solved numerically applying the ... Rodrigo and José J Linares Chapter Numerical Analysis of Heat and Mass Transfer in a Fin -and- Tube Air Heat Exchanger under Full and Partial Dehumidification Conditions Riad Benelmir and Junhua ... of topics in heat and mass transfer processes for a variety of industrial applications The research papers provide information and guidelines in terms of theory, mathematical modeling and experimental...

Ngày tải lên: 19/06/2014, 10:20