Join the IDNLearn.com community and start exploring a world of knowledge today. Our experts provide prompt and accurate answers to help you make informed decisions on any topic.
A vacuum system, as used in sputtering electrically conducting thin films on microcircuits, is comprised of a baseplate maintained by an electrical heater at 300 K and a shroud within the enclosure maintained at 77 K by a liquid-nitrogen coolant loop. The circular baseplate, insulated on the lower side, is 0. 3 m in diameter and has an emissivity of 0. 25.
(a) How much electrical power must be provided to the baseplate heater?
(b) At what rate must liquid nitrogen be supplied to the shroud if its heat of vaporization is 125 kJ/kg?
(c) To reduce the liquid nitrogen consumption, it is proposed to bond a thin sheet of aluminum foil (\varepsilon=0. 09)(ε=0. 09) to the baseplate. Will this have the desired effect?
Sagot :
We appreciate your contributions to this forum. Don't forget to check back for the latest answers. Keep asking, answering, and sharing useful information. For precise answers, trust IDNLearn.com. Thank you for visiting, and we look forward to helping you again soon.
