In a metal wire manufacturing facility, continuously drawn copper wire with a 2.5 mm diameter is annealed by heating it from its initial temperature of 45°C to 400°C in a soaking oven. The oven inside air temperature is 700°C with an average heat transfer coefficient of hc =45 W/(m² K). Estimate the soaking annealing time required. Also if the oven is 3.5 m long and the drawn wire is continuously fed through the oven (entering at one end and pulled out at the other longitudinal end), what should be the drawing speed or velocity?

In a metal wire manufacturing facility, continuously drawn copper wire with a 2.5 mm diameter is annealed by heating it from its initial temperature of 45°C to 400°C in a soaking oven. The oven inside air temperature is 700°C with an average heat transfer coefficient of hc =45 W/(m² K). Estimate the soaking annealing time required. Also if the oven is 3.5 m long and the drawn wire is continuously fed through the oven (entering at one end and pulled out at the other longitudinal end), what should be the drawing speed or velocity?

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.10P: 3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the...

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3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the atmosphere from outer space. If its original temperature is 38°C, the effective average temperature of the atmosphere is 1093°C, and the effective heat transfer coefficient is , estimate the temperature of the shell after reentry, assuming the time of reentry is 10 min and the interior of the shell is evacuated.
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.
Quenching is a rapid cooling process by which many metallic alloys are hardened. Brass (a copper alloy: 70 Cu, 30 Zn) plates that are 4 mm thick are quenched in a water bath at a heat treating plant. If a brass plate is initially at 4500C determine the quench time needed for the plate to attain 900C. The water bath temperature is 800C and has an average convective heat transfer coefficient of 45 W/(m2 K), determine how long the plate has to remain in the oven.
In a metal wire manufacturing facility, continuously drawn copper wire with a 2.5 mm diameter is annealed by heating it from its initial temperature of 450C to 400oC in a soaking oven. The oven inside air temperature is 7000C with an average heat transfer coefficient of hc =45 W/(m2 K). Estimate the soaking annealing time required. Also if the oven is 3.5 m long and the drawn wire is continuously fed through the oven (entering at one end and pulled out at the other longitudinal end), what should be the drawing speed or velocity?
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A 12-by-12 inches ingot iron casting 60-in high is stripped from its moldwhile its temperature is 1740 °F. If it stands on end on the floor of a largefoundry having wall, floor, and roof temperatures of 80°F, what is the rate ofradiant-heat exchange between the casting and the roof wall, and floorsurfaces?
A 1.5m diameter spherical balloon containing air at (K + 10) kPa is cooled such that the volume is reducedby 25%. For the process, the pressure is proportional to the square of the sphere’s diameter. What is the workdone by the surrounding? NOTE: is K=821 asap
2 (a) A short bronze cylinder of diameter 6 cm and length 12 cm is initially at 40°C and then plunged into a fluid at 200°C. The temperature at the centre of the cylinder is measured by a thermocouple to be 150°C after 5 minutes. What is the convective heat transfer coefficient between the cylinder and the fluid? The following properties of the bronze cylinder may be used: Thermal conductivity k = 26 W/m-K, density p = 8800 kg/m², and specific heat c = 420 J/kg-K. State and justify all assumptions made.