Problem 2. In cement production the intermediate product which leaves the cement kiln is calledclinker. In a certain cement production process, clinker particles leave the kiln as spherical ballsof 2 cm average radius at 300°C and cooled by blowing air at 25°C. The heat transfer coefficientbetween the air and the clinker particles can be taken as 200 W/m²K and the thermal conductivityof the clinker can be taken as 2 W/m.K. Assuming a heat diffusivity of 3x107 m²/s for the particles,estimate the time necessary for the center temperature of an average clinker particle to cool downto 50°C.

Given that T∞=25 CTi=300 Ch =200 wm2kk=2 wmkTf =50 C

Answered: Problem 2. In cement production the…

Introduction to Chemical Engineering Thermodynamics

8th Edition

ISBN:9781259696527

Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart

Publisher:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart

Chapter1: Introduction

Section: Chapter Questions

Problem 1.1P

See similar textbooks

Similar questions

Analyze the following diagram. What is the heat rate to the left side of the heater? What is the heat rate to the right side of the heater? Tin = 16°C W h = 40- T = -20°C u = 188 m2K 60mm Air 60mm 10mm 6mm 10mm 14mm 6mm 2mm 2mm Blue: Epoxy Grey: Aluminum Green: Fiberglass Yellow: Silicone Orange: Heater Blanket, 2000w Note: Treat the outer left wall as flat plates in external convection. Note: Ignore the thickness of the heater blanket.
The exhaust duct from a heater has an inside diameter of 114.3 mm with ceramic walls 6.4 mm thick. The average k=1.52 W/m· K. Outside this wall, an insulation or rock wool 102 mm thick is installed. The thermal conductivity of the rock wool is k= 0.046+ 1.56 x 104 T°C (W/m · K). The inside surface * = temperature of the ceramic is T1 = 588.7 K, and the outside surface temperature of the insulation is 311 K. Calculate the heat loss for 1.5 m of duct and the interface temperature T2 between the ceramic and the insulation. [Hint: The correct value of km for the insulation is that evaluated at the mean temperature of (T2 + T3)/2. Hence, for the first trial assume a mean temperature of, say, 448 K. Then calculate the heat loss and T2 Using this new T2, calculate a new mean temperature and proceed as before.]
A 10 cm thick piece of beef steak will be frozen in the freezer room -40 ° C. This product has a moisture content of 73%, a density of 970 kg / m³, and a thermal conductivity (frozen) of 1.1 W / (m K). Estimate the freezing time. using the Plank equation. This product has an initial freezing temperature of -1.75 ° C, and the movement of air in the freezing room gives a convective heat transfer coefficient of 15 W / (m² K). t f = hour
Example • The cylinder is made from aluminum with diameter and thickness of 5 cm and 1 cm respectively. The wall temperature in the inside of cylinder is 50°C, while the temperature of the air is 30°C. the coefficient of convection in the air is 10 W/m2-C. Calculate the heat loss from the cylinder per unit length! • Calculate the thickness of the insulation so heat loss from cylinder will decrease 50% of initial condition. Thermal conductivity of the isolator (k) : 0.5 W/m°C state.pptx 7 MB VIEW Tampilkan semua
2-2 A certain material 2.5 cm thick, with a cross-sectional area of 0.1 m², has one side maintained at 35°C and the other at 95°C. The temperature at the center plane of the material is 62°C, and the heat flow through the material is 1 kW. Obtain an expression for the thermal conductivity of the material as a function of temperature.
.240mm steam main pipe, 210m long is covered with 50mm of high temperature insulation (k-0.092 W/m °C) and 40mm of low temperature insulation (k-0.062 W/m °C). The inner and the outer surface temperature as measured are 390 °C and 40 °C respectively. Calculate: 1- The total heat loss per hour. 2- The temperature between two layers of insulation.
a piece of beef steak 7 cm thick will be frozen in the freezer room -40 degrees Celsius This product has a moisture content of 73% density 970 kg / m³ and a thermal conductivity of 1.1 W / (m K) frozen using the plank equation. This product has an initial freezing temperature of -1.75 degrees Celsius and the movement of air in the raw chamber gives a convection heat transfer coefficient of 10 W / (m² K). tf =
An industrial cold room has four 200 mm thick walls made of concrete. The walls are insulated on the outside with a layer of foam 60 mm thick. Cladding with a thickness of 15 mm protects the foam on the outside from the elements. The composite wall surface temperatures are –3 °C on the inside and 18 °C on the outside of the room respectively. The thermal conductivities of concrete, foam and cladding are 0.75, 0.35 and 0.5 W/m K respectively. a) Assuming perfect thermal contact between the layers of the composite walls, draw the typical temperature distribution across the layers and determine the heat energy gained per hour through all 4 walls of the room with a total surface area of 20 m2 . What does this heat energy represent in terms of the refrigeration system of the cold room?
Air at dry ball temperature 80 ° C and RH 4% is passed over the cooling coil so that the air dry bulb temperature becomes 35 ° C. How much heat is released from the air in the process? = ... KJ / Kg
4. A bilayer polymer slab (1.2m long, 1.4m wide, 5 cm thick) is placed on a hot plate, which keeps the side of the slab touching the hot plate at 105C. The thermal conductivity of Layer 1 (2 cm thick) is 0.44 W/mK and the thermal conductivity of Layer 2(3 cm thick) is 0.67 W/m K. If the air surrounding the slab is 27 C and the convective heat transfer coefficient between the top of the slab and the air is 20 W/m²K. What is the rate of heat transfer from the side of the slab touching the hot plate to the air?

Recommended textbooks for you

Introduction to Chemical Engineering Thermodynami…

Chemical Engineering

ISBN:

9781259696527

Author:

J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart

Publisher:

McGraw-Hill Education

Elementary Principles of Chemical Processes, Bind…

Chemical Engineering

ISBN:

9781118431221

Author:

Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard

Publisher:

WILEY

Elements of Chemical Reaction Engineering (5th Ed…

Chemical Engineering

ISBN:

9780133887518

Author:

H. Scott Fogler

Publisher:

Prentice Hall

Introduction to Chemical Engineering Thermodynami…

Chemical Engineering

ISBN:

9781259696527

Author:

J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart

Publisher:

McGraw-Hill Education

Elementary Principles of Chemical Processes, Bind…

Chemical Engineering

ISBN:

9781118431221

Author:

Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard

Publisher:

WILEY

Elements of Chemical Reaction Engineering (5th Ed…

Chemical Engineering

ISBN:

9780133887518

Author:

H. Scott Fogler

Publisher:

Prentice Hall

Process Dynamics and Control, 4e

Chemical Engineering

ISBN:

9781119285915

Author:

Seborg

Publisher:

WILEY

Industrial Plastics: Theory and Applications

Chemical Engineering

ISBN:

9781285061238

Author:

Lokensgard, Erik

Publisher:

Delmar Cengage Learning

Unit Operations of Chemical Engineering

Chemical Engineering

ISBN:

9780072848236

Author:

Warren McCabe, Julian C. Smith, Peter Harriott

Publisher:

McGraw-Hill Companies, The

SEE MORE TEXTBOOKS