A confectionery shop has a display made of molten chocolate! In order to efficiently melt chocolate and keep it molten the chocolatier has devised a system where he passes hot water (carried through parallel thin copper tubes) through a block of chocolate. As hot water passes through the block, the chocolate melts slowly maintaining a constant temperature. The length of the block and hence the water tube is 0.02-cm. The tube diameter is 1.2 cm. The melting point of chocolate is 303.75 K, and you can assume the temperature of the tube is also the same. Water enters the tubes at a mean temperature of 341.15 K with a mass flow rate of 0.06 kg/s. Find out the mean temperature of the water at the end of the block. The latent heat of fusion for chocolate is hfg = 31.2 kJ/kg. Find out the rate at which chocolate melts due the hot water flow through a single tube in it. Justify the use of any assumed temperature at the end of the problem if you make one.

A confectionery shop has a display made of molten chocolate! In order to efficiently melt chocolate and keep it molten the chocolatier has devised a system where he passes hot water (carried through parallel thin copper tubes) through a block of chocolate. As hot water passes through the block, the chocolate melts slowly maintaining a constant temperature. The length of the block and hence the water tube is 0.02-cm. The tube diameter is 1.2 cm. The melting point of chocolate is 303.75 K, and you can assume the temperature of the tube is also the same. Water enters the tubes at a mean temperature of 341.15 K with a mass flow rate of 0.06 kg/s. Find out the mean temperature of the water at the end of the block. The latent heat of fusion for chocolate is hfg = 31.2 kJ/kg. Find out the rate at which chocolate melts due the hot water flow through a single tube in it. Justify the use of any assumed temperature at the end of the problem if you make one.

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.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.29P

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