4- (Transient heat conduction) Stainless-steel ball bearings (k = 22.2 W/m K, a = 4.85 x 10-6 m 2 /s) which have uniformly been heated to 850°C are hardened by quenching them in an oil bath that is maintained at 40°C. The ball diameter is 20 mm, and the convection coefficient associated with the oil bath is 600 W/m2 K. (a) If quenching is to occur until the surface temperature of the balls reaches 100°C, how long must the balls be kept in the Oil? (b) If 10000 balls are to be quenched per hour, what is the rate at which energy must be removed by the oil-bath cooling system in order to maintain its temperature at 40°C?

4- (Transient heat conduction) Stainless-steel ball bearings (k = 22.2 W/m K, a = 4.85 x 10-6 m 2 /s) which have uniformly been heated to 850°C are hardened by quenching them in an oil bath that is maintained at 40°C. The ball diameter is 20 mm, and the convection coefficient associated with the oil bath is 600 W/m2 K. (a) If quenching is to occur until the surface temperature of the balls reaches 100°C, how long must the balls be kept in the Oil? (b) If 10000 balls are to be quenched per hour, what is the rate at which energy must be removed by the oil-bath cooling system in order to maintain its temperature at 40°C?

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Related questions

Q: 1) Hot water at an average temperature of 60°C is flowing through a 10-m section of a cast iron pipe…

A: Temperataure of water inside the pipe, T1=60 °C,Length of the pipe, L=10 m,Thermal conductivity of…

Q: A composite walls are constructed from an inner brick wall with thick L1= 25 cm and k1= 0.4 W/m K, a…

A: Please find the solution below.

Q: based on the information given here. Steam in a heating sy diameter is 5-cm and whose walls are…

Q: 3.26 A composite wall separates combustion gases at 2600°C from a liquid coolant at 100°C, with gas-…

Q: 50 W/m2 . K. If the dimensions of the brick are 0.06 m × 0.09 m × 0.20 m, determine the temperature…

Q: In general, it is helpful to think of a thermally lumped object as being "tied down" to some…

Q: An industrial process to harden ball bearings involves quenching them in a cooling bath at 40°C. The…

Q: Q11/ To heat treat alloy rods, these are placed in a gas stream at 800°C with a convective heat…

Q: A thick-walled tube of stainless (A) having k=21.63 W/m.K with dimensions of 0.0254 m ID and 0.0508…

Q: A single-glazed glass window pane is an arched shape, consisting of a semicircle of radius 0.5 m on…

Q: Q) The condenser of a steam power plant contains N = 1000 brass tubes (K= 110 W/m.K), each of inner…

Q: Explore the effect of insulation thickness on the heat loss q and the temperature of the nsulation…

A: The problem can be sketched as follows,

Q: The walls of a refrigerator are typically constructed by sand- wiching a layer of insulation between…

A: Given: Inside temperature (T∞,i)=4°COutside temperature…

Q: based on the information given here. Steam in a heating system flows through tubes whose outer…

A: Given Surface area, A = 0.001916 m2 Thermal conductivity, k = 186 W/ moC…

Q: What are the methods and techniques for enhancement in two-phase heat transfer (boiling and…

A: Enhancement refers to improvement of heat transfer processes either by the heat removal rate or heat…

Q: In a metal wire manufacturing facility, continuously drawn copper wire with a 2.5 mm diameter is…

A: Given data: d=2.5 mmL=3.5 mh=45 W/m2KT=400°CT∞=700°CTo=45°C Need to determine the required annealing…

Q: A bearing piece in the form of half of a hollow cylinder of 60 mm ID, 90 mm OD and 100 mm long is to…

Q: image 109

Q: based on the information given here. Steam in a heating system flows through tubes whose outer…

A: The answer is Ccannot be determined, since the no. of fins is not given.But I assumed it to be 250,…

Q: An egg (k = 0.6 W/m-K, r = 1100 kg/m3, cp = 3000 J/kg-K) is removed from boiling water at 95°C and…

A: Apply the energy balance equation for both conditions.

Q: (2) Calculate the heat flux and overall heat transfer coefficient for two-layer wall, which consists…

Q: A 10 cm diameter cylindrical bar, heated in furnace to a uniform temperature of 2000 C, is allowed…

A: given; diameter(d)=10cm =0.1m temperature of surroundings(T1)=2000cenviornment…

Q: (B) Cylindrical Water cans (diameter 6.5cm and length 15cm) are to be cooled from initial…

A: Introduction: Convection is the transmission of heat energy between a stationary surface and a…

Q: During normal operation of a nuclear reactor, the highest power density in fuel pellets is equal to…

A: Heat transfer from the clad surface is given as, Q''=h(Tco-Tlb)where, h is convective heat transfer…

Q: 5.39 Consider an acrylic sheet of thickness L = 5 mm that is used to coat a hot, isothermal metal…

A: solution 5.39 :-

Q: During transient operation, the steel nozzle of a rocket engine must not exceed a maximum allowable…

A: Tmax.=1500kh=5000 w/m2.kk=10 W/m.K* The ceramic temperature at x=0, corresponds to the maximum wall…

Q: Steel balls 10 mm in diameter are annealed by heating to 1,150 K and then slowly cooling to 450 K in…

A: Given Diameter, d = 10 mm Thermal conductivity, k = 40 W/mK Convection…

Q: 5.10 A steel sphere (AISI 1010), 100 mm in diameter, is coated with a dielectric material layer of…

A: The diameter of sphere is The thickness of dielectric matrial is The thermal conductivity of…

Q: An aluminum bar (6061-T4) is initially 250.00 mm long at a temperature of 50°C. It is placed between…

Q: Required information Consider a very long, slender rod. One end of the rod is attached to a base…

Q: Consider a 1 cm thick copper wall (k=375 W/m K) whose one surface is exposed to condensing water…

Q: Liquid oxygen which is boiling at 61 K is stored in a spherical container, 1 m in diameter covered…

Q: manufacturer plans to use steel wire (ks = 25 Wm-1 K-1 ) in a household appliance. For safety…

Q: In a metal wire manufacturing facility, continuously drawn copper wire with a 2.5 mm diameter is…

Q: A 11-mm radius fuel rod in a nuclear reactor is insulated by a r,-radius graphite shell to block the…

A: (a) The outer radius of the cylindrical shell must be equal to the critical radius of insulation and…

Q: knowing that: 0,2 m, 2,=25 W/(m =0,1 m, 2g=1 W/(m =0,2 m, 23=0,02 W

Q: PROBLEM 7: 4-58 A long iron rod (p = 7870 kg/m³, cp = 447 J/kg-K, k= 80.2 W/m-K, and a = 23.1 x 10-6…

A: The density of the rod is ρ=7870 kg/m3. The specific heat capacity of the rod is Cp=447 J/kgK. The…

Q: If the cost of producing the hot water is $0.10 per kWh, what is the representative daily cost of…

Q: A 112 m steel pipe has a 246.4˚C temperature, diameter of 230.8 mm is insulated with a 203.9 mm…

Question

4- (Transient heat conduction) Stainless-steel ball bearings (k = 22.2 W/m K, a = 4.85 x 10-6 m 2 /s) which have uniformly
been heated to 850°C are hardened by quenching them in an oil bath that is maintained at 40°C. The ball diameter is 20
mm, and the convection coefficient associated with the oil bath is 600 W/m2 K. (a) If quenching is to occur until the
surface temperature of the balls reaches 100°C, how long must the balls be kept in the Oil? (b) If 10000 balls are to be
quenched per hour, what is the rate at which energy must be removed by the oil-bath cooling system in order to maintain
its temperature at 40°C?
Oil
T = 40°C
h = 1500 W/m²°C
-Ball bearing
D = 22.4 mm
= 600°C
T₁
To

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1: Given Data

VIEW

Step 2: To check whether the lumped capacitance method applicable or not and parameters

VIEW

Step 3: Calculations for dimensionless temperature parameter and Fourier Number

VIEW

Step 4: Time to kept ball in oil

VIEW

Step 5: Total amount of Energy removed from oil bath

VIEW

Solution

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 6 steps

SEE SOLUTION Check out a sample Q&A here

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

Carbon steel balls (D= 26.8 mm, p 7833 kg/m", k = 54 W/m-K, c, 0.465 kJ/kg. C), are annealed by heating them first to 900°C in a furnace and then allowing them to cool slowly to 100°C in ambient air at 35°Ç. If the average heat transfer coefficient is 9.8 W/m-K, How in long the annealing process will take (in seconds)?
molten salt at 920 K. Data for molten salt: 10 K¹: (920 K) 1.65 x 10³ N s m². 8.20 A steel rod (25 mm diameter and 0.6 m length) is heated vertically in a large bath of Calculate the heat transfer coefficient when the bar is at 640 K. = 870 J kg K¹; p = 3200 kg m³; ß = 2 x k = 86 W m¹ K¹; C, : 1.03 x 10³ N s m²; n(780 K) = 1.24 x 10³ N s m²; n(640 K) =
3. A composite plain wall is to be constructed of (1/4)-in. stainless steel (k-17.03 W/m-K), 3-in. of corkboard (k=0.04 W/m-K) and (1/2)-in. of plastic (k=2.6 W/m-K). (a) Draw a thermal circuit for the steady-state heat conduction through this wall; (b) Evaluate the individual thermal resistances of each material layer; (c) Determine the heat flux if the inside steel surface is maintained at 400 K and the outer surface of plastic surface is held at 300 K; and (d) What are the temperatures on each surface of the corkboard under these conditions?
Problem: A solid copper cube of 10-cm edge length(p =8954 kg/m³, c = 383 J/kg.K, k= 386 W/m.K) initially at a uniform temperature T;= 250°C is suddenly immersed in a well-stirred fluid which is maintained at a uniform temperature T = 50 °C. The heat transfer coefficient between cube and the fluid h=20O W/m²K. A. Check whether the lumped system analysis is suitable. B. Determine the temperature of the copper block at t= 5 min after the immersion. TE 250°C 10 cm Tm= 50 °C, h=200 w/mk
Plate glass 5 mm thick at 200°C is to be cooled from both sides using air at 40°C. If surface cracks are to be avoided, determine the maximum value of convective heat transfer coefficient. Material properties are density = 2500 kg/m3, = specific heat 670 J/kgK. Thermal conductivity 0.744 W/mk. Also determine the time required in this to cool the plate to 80°C. o 12:03
What is true option
14- A south wall group D at (32 oN, Kw = 0.65). The room temperature is (24 oC). The maximum outside temperature is (42 oC). The daily range is (12 oC). Its heat transfer coefficient is (1.2 W/m2.oC) and dimensions are (5 x 3 m) with door of dimensions of (1.5 x 2 m). At (17 PM) in August, its Cooling load is Select one: a. 361.7 W b. None of these c. 261.7 W d. 303 W
14- A south wall group D at (32 oN, Kw = 0.65). The room temperature is (24 oC). The maximum outside temperature is (42 oC). The daily range is (12 oC). Its heat transfer coefficient is (1.2 W/m2.0C) and dimensions are (5 x 3 m) with door of dimensions of (1.5 x 2 m). At (17 PM) in August, its Cooling load is Select one: Q2 a. 361.7 W b. None of these c. 261.7 W d. 303 W
A 50-mm thick plate of carbon steel (AISI 1010) is annealed with a reheat stage taking the steel from its initial uniform temperature of 200 C to a minimum final temperature of 550 C. HEating is effected in a gas-fired furnace where products of combustion at Tamb = 800 C maintain a convection coefficient of h = 100 W/m^2K on both sides of the plate. How long should the plate be left in the furnace? Substantiate with relevant analysis and calculations.
(B) Cylindrical Water cans (diameter 6.5cm and length 15cm) are to be cooled from initial temperature of 20°C by placing theme in a cooler with ambient temperature of 1°C. Compare the initial cooling rates when the cans are laid horizontally to when the cans are laid vertically. Take v = 15.55x10° m²/s, k=0.024 W/mK and Pr=0.7. Nu = 0.53RA' a4 for horizontal orientation Nu = 0.59 Ra"4 for vertical orientation
Can you help me answer my sample problem for my review?
At a particular location, the soil is initially at a uniform temperature of 15°C and the soil is subjected to a sub zero temperatúre of -20°C continuously for 50 days. What is the minimum burial depth required to ensure that the water in the pipes does not freeze? i.e., pipe surface temperature should not fall below 0°C.