Water is boiled at atmospheric pressure in a square (0.2 m x 0.2 m) pan placed on top of a heating unit. Pan is made of polished copper and the surface tension of liquid-vapor interaction is 0.06 N/m. The coefficient Ccr is 0.15. What should be the maximum bottom surface temperature of the pan for safe operation? Properties of water: ρl=960 kg/m3 ρv=0.6 kg/m3 μl=0.3x10-3 kg/ms cpl=4200 J/kgK Prl=2 hfg=2257x103 J/kg

Water is boiled at atmospheric pressure in a square (0.2 m x 0.2 m) pan placed on top of a heating unit. Pan is made of polished copper and the surface tension of liquid-vapor interaction is 0.06 N/m. The coefficient Ccr is 0.15. What should be the maximum bottom surface temperature of the pan for safe operation? Properties of water: ρl=960 kg/m3 ρv=0.6 kg/m3 μl=0.3x10-3 kg/ms cpl=4200 J/kgK Prl=2 hfg=2257x103 J/kg

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.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.28P

See similar textbooks

Similar questions

Water is boiled at 250°F by a 2-ft-long and 0.5-in diameter nickel-plated electric heating element maintained at 280°F. Determine (a) the boiling heat transfer coefficient, (b) the electric power consumed by the heating element, and (c) the rate of evaporation of water.
Is it true that water boils at higher temperature at higher pressure? Explain.
How does a boiling process at supercritical pressures differ from the boiling process at subcritical pressures?
the latent heat of vaporization is about 2.44 x 10⁶ J/kg and the density (density) of the vapor is 0.598 kg/m³ at 100 °C per km. Determine the rate of change of the boiling point with altitude approaching sea level in °C per km. It is known that the density of air at 0°C and 1 atm is 1.29 kg/m and the density of water is 1000 kg/m³. Assume the air temperature is 300°K. The change in pressure with altitude is given by the relationship P(z) = P(0)exp - (mgz)/(kT)
(About measuring specific heat capacity) Since metal sample can be heated to any desired temperature value, say, 65°C or 156°C. Why is it practical to set the initial temperature of the metal sample near the boiling point of water? In connection to this, why should the dipper be partly submerged in the water while heating the metal sample?
The normal boiling point of copper is 2845 K and its molar enthalpy of vvaporization is 300.3 kj/mol. What is the change in the entropy in the system when 127 g of copper vapor condenses to liquid at the normal boiling point? MW=63.5
The average atmospheric pressure in Denver (elevation = 1610 m) is 83.4 kPa. Determine the temperature at which water in an uncovered pan boils in Denver.
If 10kg of water at 920kPa pressure and at 600C is heated to boiling point, then to dry saturated steam and then to superheated steam at a temperature of 2100C, determine: The sensible heat and latent heat
In what kind of pot will a given volume of water boil at a higher temperature: a tall and narrow one or a short and wide one? Explain.
When boiling food the cooking temperature is limited to about 100° C. Pressurecookers allow for faster cooking by increasing the boiling temperature of water using increased pressure. The pressure within the sealed cooker can be variedby using different weights to seal the vent. A pressure cooker containing 4kgof water is to be used to cook potatoes at 150° C determine (a) what pressureis necessary to maintain the desired boiling temperature and (b) the mass ofthe weight that must be used in order to maintain the pressure determined inpart (a) given a round vent with a diameter of 1cm, (c) if the pressure cookerhas a volume of 10L what is the quality of the steam within the pressure cookerthe instant it reaches temperature, before any steam is vented (assuming allair has been purged from the cooker by this point) , and (d) how long can thepotatoes be cooked at the desired temperature before all the water is boiledaway if heat is being added to the system by a 7000 Watt burner. vf =…
What is the ΔH(vap)° of a liquid that has a vapor pressure of 621 torr at 85.2°C and a boiling point of 95.6°C at 1 atm?
When boiling food the cooking temperature is limited to about 100° C. Pressure cookers allow for faster cooking by increasing the boiling temperature of water using increased pressure. The pressure within the sealed cooker can be varied by using different weights to seal the vent. A pressure cooker containing 5kg of water is to be used to cook potatoes at 150°C determine (a) what pressure is necessary to maintain the desired boiling temperature and (b) the mass of the weight that must be used in order to maintain the pressure determined in part (a) given a round vent with a diameter of 1cm, (c) if the pressure cooker has a volume of 15L what is the quality of the steam within the pressure cooker the instant it reaches temperature, before any steam is vented (assuming all air has been purged from the cooker by this point) , and (d) how long can the potatoes be cooked at the desired temperature before all the water is boiled away if heat is being added to the system by a 8000 Watt burner