Introduction to Heat Transfer
6th Edition
ISBN: 9780470501962
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 1, Problem 1.68P
Following the hot vacuum forming of a paper-pulp mixture, the product, an egg carton, is transported on a conveyor for 18 s toward the entrance of a gas-fired oven where it is dried to a desired final water content. Very little water evaporates during the travel time. So, to increase the productivity of the line, it is proposed that a bank of infrared radiation heaters, which provide a uniform radiant flux of
The chief engineer of your plant will approve the purchase of the heaters if they can reduce the water content by
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Provide the answers with clear explantion and images.
Coolant flowing through a radiator at the rate of 3 kg/s are cooled from 105 0C to 81 0 The specific heat capacity of coolant and air are 4.19 kJ/kg K and 1.13 kJ/kJ/K respectively. Th overall heat transfer coefficient from gas to water is 140 W/m2 K. Calculate the surface area required for the radiation if the vehicle speed is 100 km/h. Consider the density of air as 1.225 kg/m3.
Recent studies show that the major energy consumption
in Fijian villages is wood which is used
for cooking on open fires. Typical consumption of wood
is 1 kg/person/day. (a) Estimate the heat
energy required to boil a 2 litre pot full of water.
Assuming this to be the cooking requirement of
each
person, compare this with the heat content of the
wood, and thus estimate the thermal
efficiency of the open fire. (b) How much timber has to
be felled each year to cook for a village
of 200 people ? Assuming systematic replanting, what
area of crop must the village therefore
set aside for fuel use if it is not to make a net
deforestation ?
Ammonia is to be removed from a 10 per cent ammonia-air mixture by countercurrent
scrubbing with water in a packed tower at 293 K so that 99 per cent of the ammonia is
removed when working at a total pressure of 101.3 kN/m². If the gas rate is 0.95 kg/m?s
155
of tower cross-section and the liquid rate is 0.65 kg/m²s, what is the necessary height of
the tower if the absorption coefficient Kga = 0.001 kmol/m³s (kN/m²) partial pressure
difference. The equilibrium data are:
Concentration
(kmol NH3/kmol
water)
Partial pressure
NH3 (kN/m²)
0.021
0.031
0.042
0.053
0.079
0.106
0.150
1.6
2.4
3.3
4.2
6.7
9.3
15.2
Chapter 1 Solutions
Introduction to Heat Transfer
Ch. 1 - The thermal conductivity of a sheet of rigid,...Ch. 1 - The heat flux that is applied to the left face of...Ch. 1 - A concrete wall, which has a surface area of 20m2...Ch. 1 - The concrete slab of a basement is 11 m long, 8 m...Ch. 1 - Consider Figure 1.3. The heat flux in the...Ch. 1 - Prob. 1.6PCh. 1 - The inner and outer surface temperatures of a...Ch. 1 - A thermodynamic analysis of a proposed Brayton...Ch. 1 - A glass window of width W=1m and height H=2m is 5...Ch. 1 - Prob. 1.10P
Ch. 1 - The heat flux that is applied to one face of a...Ch. 1 - Prob. 1.12PCh. 1 - Prob. 1.13PCh. 1 - Prob. 1.14PCh. 1 - The 5-mm-thick bottom of a 200-mm-diameter pan may...Ch. 1 - Prob. 1.16PCh. 1 - For a boiling process such as shown in Figure...Ch. 1 - You've experienced convection cooling if you've...Ch. 1 - Prob. 1.19PCh. 1 - A wall has inner and outer surface temperatures of...Ch. 1 - An electric resistance heater is embedded in a...Ch. 1 - Prob. 1.22PCh. 1 - A transmission case measures W=0.30m on a side and...Ch. 1 - Prob. 1.24PCh. 1 - A common procedure for measuring the velocity of...Ch. 1 - Prob. 1.26PCh. 1 - Prob. 1.27PCh. 1 - Prob. 1.28PCh. 1 - Prob. 1.29PCh. 1 - Prob. 1.30PCh. 1 - Prob. 1.31PCh. 1 - Prob. 1.32PCh. 1 - Prob. 1.33PCh. 1 - Prob. 1.34PCh. 1 - An electrical resistor is connected to a battery,...Ch. 1 - Pressurized water pin=10bar,Tin=110C enters the...Ch. 1 - Consider the tube and inlet conditions of Problem...Ch. 1 - An internally reversible refrigerator has a...Ch. 1 - A household refrigerator operates with cold- and...Ch. 1 - Chips of width L=15mm on a side are mounted to a...Ch. 1 - Consider the transmission case of Problem 1.23,...Ch. 1 - One method for growing thin silicon sheets for...Ch. 1 - Heat is transferred by radiation and convection...Ch. 1 - Radioactive wastes are packed in a long,...Ch. 1 - An aluminum plate 4 mm thick is mounted in a...Ch. 1 - A blood warmer is to be used during the...Ch. 1 - Consider a carton of milk that is refrigerated at...Ch. 1 - The energy consumption associated with a home...Ch. 1 - Liquid oxygen, which hems a boiling point of 90 K...Ch. 1 - The emissivity of galvanized steel sheet, a common...Ch. 1 - Three electric resistance heaters of length...Ch. 1 - A hair dryer may be idealized as a circular duct...Ch. 1 - In one stage of an annealing process, 304...Ch. 1 - Convection ovens operate on the principle of...Ch. 1 - Annealing, an important step in semiconductor...Ch. 1 - In the thermal processing of semiconductor...Ch. 1 - A furnace for processing semiconductor materials...Ch. 1 - Single fuel cells such as the one of Example 1.5...Ch. 1 - Prob. 1.59PCh. 1 - Prob. 1.60PCh. 1 - Prob. 1.61PCh. 1 - A small sphere of reference-grade iron with a...Ch. 1 - A 50mm45mm20mm cell phone charger has a surface...Ch. 1 - A spherical, stainless steel (AISI 302) canister...Ch. 1 - Prob. 1.65PCh. 1 - Prob. 1.66PCh. 1 - A photovoltaic panel of dimension 2m4m is...Ch. 1 - Following the hot vacuum forming of a paper-pulp...Ch. 1 - Prob. 1.69PCh. 1 - Prob. 1.70PCh. 1 - Prob. 1.71PCh. 1 - The roof of a car in a parking lot absorbs a solar...Ch. 1 - Prob. 1.73PCh. 1 - Prob. 1.74PCh. 1 - Consider Problem 1.1. If the exposed cold surface...Ch. 1 - Prob. 1.76PCh. 1 - Prob. 1.77PCh. 1 - A thin electrical heating element provides a...Ch. 1 - Prob. 1.79PCh. 1 - Prob. 1.80PCh. 1 - Prob. 1.81PCh. 1 - The curing process of Example 1.9 involves...Ch. 1 - The diameter and surface emissivity of an...Ch. 1 - Bus bars proposed for use in a power transmission...Ch. 1 - A solar flux of 700W/m2 is incident on a...Ch. 1 - In considering the following problems involving...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- 8.15 A mercury bath at is to be heated by immersing cylindrical electric heating rods, each 20 cm tall and 2 cm in diameter. Calculate the maximum electric power rating of a typical rod if its maximum surface temperature is .arrow_forward7.43 Liquid sodium is to be heated from 500 K to 600 K by passing it at a flow rate of 5.0 kg/s through a 5-cmID tube whose surface is maintained at 620 K. What length of tube is required?arrow_forward3.5 In a ball-bearing production facility, steel balls that are each of 15 mm in diameter are annealed by first heating them to 870°C and then slowly cooling in air to 125°C. If the cooling air stream temperature is 60°C, and it has a convective heat transfer coefficient of , determine the time required for the cooling.arrow_forward
- Determine the power requirement of a soldering iron in which the tip is maintained at 400C. The tip is a cylinder 3 mm in diameter and 10 mm long. The surrounding air temperature is 20C, and the average convection heat transfer coefficient over the tip is 20W/m2K. The tip is highly polished initially, giving it a very low emittance.arrow_forwardQuestion : Studies show that the major energy consumption in Fijian villages is wood which is used for cooking over open fires. Typical consumption of wood is 1 kg person–1day–1. (a) Estimate the heat energy required to boil a 2-liter pot full of water. Assuming this to be the cooking requirement of each person, compare this with the heat content of the wood, and thus estimate the thermal efficiency of the open fire. (b) How much timber has to be felled each year to cook for a village of 200 people?Assuming systematic replanting, what area of crop must the village therefore set aside for fuel use if it is not to make a net deforestation? Hint: refer to Table 10.4. (c) Comment on the realism of the assumptions made, and revise your estimates accordingly. Answer: (a) mcDT ≈ 0.6 MJ (heat losses from pot imply actual requirement is higher). h ≈ 3%. (b) 70 tonnes; 7 ha.arrow_forwardA bioengineer working at chemical company intends to dry an insoluble wet granular material in a pan 0.6 x 0.6 m and 3 cm deep. The material is at the same dept in the pan, whereas the sides and the bottom can be considered to be insulated. Heat transfer is by convection from an air stream flowing parallel to the surface at a velocity of 10 m/s. The air is at 65.6°C and has a humidity of 0.010 kg H2O/kg dry air. Calculate the rate of drying for constant-rate periodarrow_forward
- You, a process design engineer, are tasked to build a powerplant that utilizes 1.5 metric tons of municipal solid wastes (MSW) per hour. In an industrial boiler, MSW is burned to heat and pressurize 1 kg/s of preheated water to high-pressure steam (44 atm, 450 °C). The high-pressure steam, moving at a linear velocity of 70 m/s, is then used to drive a high-pressure turbine. In a heat exchanger, the used steam from the outlet of high-P turbine at an intermediate pressure (10 atm, 250 °C) is used to preheat the water that will be fed to the boiler. This water is pumped from an underground reservoir at a low velocity (1 atm, 25 °C). After preheating the water, the intermediate-pressure steam leaving the heat exchanger is then used to drive a low-pressure turbine. Lastly, the steam from outlet of the low-P turbine leaves at a velocity of 10 m/s (at 1 atm and 100 °C) via an exhaust 10 m above the pump inlet. The industrial boiler is insulated, but due to the high temperatures and the nature…arrow_forwardIf we neglect radiative heat transfer, what is the appropriate heat transfer coefficient value for stagnant ambient air?arrow_forwardA manufacturing plant of 5500 square meters has 3.8 m high ceilings and changes its inside air three times per hour by maintaining a slightly positive air pressure (100kPa). The roomtemperature is maintained at 23°C. To assist in the sizing of a heating system it is assume in the design conditions that the outside temperature is -20°C. Basing the heating requirements on the indoor conditions, determine the heating required to compensate for the infiltration.A. 881.5 kwB. 188.5 kwC. 588.1 kwD. 511.8 kwarrow_forward
- 2-D: A fin may be manufactured as an integral part of a surface by using a casting or extrusion process, or it may be separately brazed or adhered to the surface. From thermal considerations, which option is preferred? 2-E: What is the difference between steady-state and transient heat transfer processes? Give an example for each of them. 2-F: What is the physical interpretation of the Biot number? 2-G: For flow over a flat plate, sketch variation of local convective heat transfer coefficient, h(x), versus the distance along the plate x for laminar, transition, and turbulent flow regimes.arrow_forwardOnce upon a time, a student from a certain university wants to learn crystallization using a Swenson-Walker crystallizer. The capacity of this crystallizer is 0.6124 Ib/s of FeSO4 slurry leaves at 300 K. The flow mechanism of the cooling is counter current through the jacket and its temperature increases from 61 to 70 F. The overall heat transfer coefficient has been estimated to be 190 Sl units. (). Determine the requirement for cooling water in kg/hr (i) Let supposed that each crystallizer unit is 3.5 yard long and each metre of crystallizer provides26.91 ft? surface, how many crystallizer units will be required?arrow_forwardFor stationary applications, mass and volume considerations for a fuel source are much less important than they are for use in transportation. It therefore may be the most reasonable to sacrifice compactness to minimize requirements for expensive advanced technologies. Consider a plan to provide power to a small city with a population of 100,000, using hydrogen fuel cells with an efficiency of 60%. The average net per-capita power consumption is 6 kW of electricity, heat, and power for an electric vehicle. (a) Calculate the volume of hydrogen needed to provide the city's energy for one month if the hydrogen is stored at a (relatively low) pressure of 1 MPa. (b) If the city has a land area of 100 km2, what fraction of this area would need to devoted to hydrogen storage if the storage tanks were vertical cylinders 3 m in diameter and 5 m high and were packed tightly together in a square array?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license