3 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 long the annealing process will take (in seconds)?

3 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 long the annealing process will take (in seconds)?

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

Similar questions

In an aluminum container weighing 0.30 kg are 0.70 kg of water in thermal equilibrium at a temperature of 70°C. Container and water temperature together cool at a rate of 2.5 K/min. What is the heat flux leaking from the container?
Steel balls (diameter = 21 mm, p = 7833 kg/m , k = 54 W/m•°C, Cp = 0.465 kJ/kg.°C, and a = 1.474x10 m /s) are annealed by heating them first to 870°C in a furnace and then allowing them to cool slowly to 85°C in ambient air at 27°C. What is the total rate of heat %3D transfer from the balls to the ambient air, when 2367 balls are to be annealed per hour (kW)? Select one: A. 11.15 B. 9.12 C. 9.85 D. 8.38 E. 10.50
Calculate the amount of heat required (in kJ) to raise the temperature of 23.4 g of ice at -11°C to steam at 135°C. ΔHvap = 40.67 kJ/mol, ΔHfus = 6.008 kJ/mol, Cice = 2.092 J/g°C, Cwater = 4.184 J/g°C, Csteam = 1.841 J/g°C, Melting point = 0.00°C, Boiling Point = 100.0°C
Please solve this prob, Thank you
Sample Problem • Four metric tons of pork are to be stored at a temperature of -12°C in 8 hours. The product enters the chiller at a temperature of 21°C and the specific heats above and below freezing are 0.86 kCal/kg-°C and 0.51 kcal/kg-°C, respectively, and its latent heat of fusion is 48 kCal/kg. If the freezing temperature of the product is -5°C, determine the product load in kCal/hr. TCL
In a dairy operation, milk at a flow rate of 0.25m3/hr and a cow-body temperature of 38.6°C must be chilled to a safe-to- store temperature of 13°C. Cold water at 2.2°C is available at a flow rate of 0.94m3/hr. The density and specific heat of milk are 1030 kg/m3 and 3860 J/kg.K, respectively. The density and specific heat of water is 1000 kg/m3 and 4187 J/kg.K. The chilling process is done by a double pipe counter-flow exchanger with an overall heat transfer coefficient U=1000 W/m2.K. The pipe of the heat exchanger has a 50-mm diameter with negligible thickness. Determine the pipe length L required. Select one: O a. 2.28 m O b. 4.28 m O c. 3.28 m O d. 1.28 m
Design a solar chimney to cover 75% of total heating losses, where U value for the chimney=0.5 W/m2.K and the total wall area of the spaces equal 70m2 and the temperature outside are 5oC at night and 8oC at day and the temperature for the interior is 24 oC.
A short brass cylinder (p = 8530 kg/m³, cp=0.389 kJ/kg-K, k=110 W/m-K, and a = 3.39×10−5 m²/s) of diameter 4 cm and height 20 cm is initially at a uniform temperature of 140°C. The cylinder is now placed in atmospheric air at 20°C, where heat transfer takes place from the cylinder 15 min after the start of the cooling by convection with a heat transfer coefficient of 40 W/m2.K. Solve this problem using the analytical one-term approximation method. Interpolate table 4-2 to obtain constants ₁ and A₁. For Biot number values less than 0.01 approximate it as 0.01 for use in Table 4-2. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. 20 cm Brass cylinder 4 cm TiºC Ambient air 20°C Calculate the center temperature of the top surface of the cylinder. The center temperature of the top surface of the cylinder is 61 °C.
4. A self-supported steel plate of 8 cm thickness and an initial temperature of 20°C passes through a convective oven at a temperature of 1980°C. What is the core temperature of the plate after 2 minutes? Given: h= 500 w/mk, Ksteel = 63.9W/m k, Csteel = 434 J/m k, Psteel = 7832 kg/m³, Osteel = 18.8 x 10-6 m²/s, Neglect Radiation (State all assumptions and Show All Work)
A 50-kg box of beef at 8°C having a water content of 72 percent is to be frozen to a temperature of -30°C in 4 hours. Freezing point is at -2°C. Specific heat of the beef above freezing is 3.23 kJ/kg.K and below freezing is 1.5 kJ/kg.K. Determine (a) the total amount of heat that must be removed from the beef, (b) the average rate of heat removal from the beef.
A 1200 W electric resistance heating element whose diameter is 0.5 cm is immersed in 55 kg of water "ep 4.18 kJ/kg.K" initially at 20 C. Assuming the water container is well-insulated. What is the gutropy generated during this process, " kJ/K" when the surroundings are at T-15 C?
An aluminum alloy sphere 10cm in diameter has a uniform temperature of 200°C after being removed from a hot oven. The aluminum sphere is then left in a cold room of 15°C and being blown by forced air. The convection heat transfer coefficient from the air flow is assumed to be h = 500 W/m²K Use the following properties to solve the problem: k = 163 W/mK, p = 2810 kg/m³, C₂ = 880J/kg°C. a. Using Lump Model, determine the temperature of the sphere after 2 minutes. b. Determine the required convective heat transfer (h) to cool the sphere from 200°C to 80°C in 3 minutes.