Find out the diameter of the spherical product being frozen in an air-blast wind tunnel. The initial product temperature is 100C & cold air in the tunnel is at -120C. The product density is 1000 kg/m3 and the convective heat transfer coefficient for the air blast is 50 W/m2K. The thermal conductivity of the product is 1.25 W/mK and the initial freezing temperature is -20C. The latent heat of fusion is 300 kJ/kg. Freezing time is 2.2 hrs

Find out the diameter of the spherical product being frozen in an air-blast wind tunnel. The initial product temperature is 100C & cold air in the tunnel is at -120C. The product density is 1000 kg/m3 and the convective heat transfer coefficient for the air blast is 50 W/m2K. The thermal conductivity of the product is 1.25 W/mK and the initial freezing temperature is -20C. The latent heat of fusion is 300 kJ/kg. Freezing time is 2.2 hrs

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 3.2P: 3.2 High-strength steel is required for use in building structures and equipment (e.g., cranes). It...

See similar textbooks

Similar questions

An industrial company manufactures tungsten cubes that need to be sintered to a temperature of 800K after processing. Hot combustion gas at 100OK is used to heat the tungsten cubes with a side length of 0.3m. The cube is initially at a temperature of 298K. Calculate the time that is needed for the cube to reach 800K. Be sure to show that you have verified your method is valid. 0.3m T: 1000K h: 100 W/m?/K
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
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.
Problem 1: Determine the amount of heat removed from 1.5 kg of bologna (sausage) when cooled from 24C to -7C.Assume MC of 59% and at -7C, 22% won’t be frozen. Problem 2: Estimate the thermal diffusivity of butter at 20°C.
Once upon a time, a student from a certain university wants to learn crystallization using a Swenson-Walker crystallizer. The capacity of this crystallizer is 0.6124 Ib/s of FeSO4 slurry leaves at 300 K. The flow mechanism of the cooling is counter current through the jacket and its temperature increases from 61 to 70 F. The overall heat transfer coefficient has been estimated to be 190 Sl units. (). Determine the requirement for cooling water in kg/hr (i) Let supposed that each crystallizer unit is 3.5 yard long and each metre of crystallizer provides26.91 ft? surface, how many crystallizer units will be required?
A polished stainless steel sphere (r= 5cm) is at a temperature of 540 C. The ambier air is at 20 C. What is the instantaneous heat transfer rate?
2000kg cast iron housing at 450 degree Celsius is quenched in 5000kg of water at 15 degree C. What is the amount of heat transferred to water, use specific heat of water to be 4.18 kJ/kg.K and specific heat of iron to be 0.42 kJ/kg.K
for COVID vaccine. The volume of the storage container will be 1 m³. You are debating on three shapes: (a) a rectangular shaped box with 20-cm thickness, 1-m 56.42 cm diameter, and width, and 5-m length; (b) a cylindrical storage with 4-m length and (a) a sphere. AS part of your design decision, find out the convective heat transfer rate from each of these containers. Assume the surface temperature to be uniform at –-10°C, and the ambient air is flowing at 20°C. The velocity of the air is 0.8 m/s. The direction of flow is over the 1-mx5-m sides of the box along the length (5-m) and across the cylinder and the sphere. Ignore the heat transfer from the end areas (i.e., the thickness of the rectangular box and the ends of the cylinder).
(h) A single-glazed glass window pane is an arched shape, consisting of a semicircle of radius 0.5 m on top of a rectangle 1.0 m wide by 2.0 m high, with no joints. The glass pane is 5 mm thick. One side of the window is exposed to air at 20°C and the other side is exposed to air at 5°C. Assuming convective heat transfer on both sides of the window, and conduction through it, determine the total thermal resistance of the window pane and hence the rate of heat transfer through it. (Convection: h = 15 W/m²K; Glass: k = 1.1 W/mK)
A moist cement omnes diameter 10 ohm circular cross-section will be dried using air in a tray and, for example, the variation of moisture content over time will be examined. The heat transfer coefficient was calculated as 0.68 cal/min.cm³.C in the fixed still drying arab. Dry and wet chamber temperatures of the air used for drying are 35 and 20°C, respectively. For example, calculate the mass transfer coefficient during the 10-minute constant speed drying interval. (Note: the humidity of the air (Ha) should be calculated with the humidity diagram.) Data Evaporation enthalpy of water: 2454.2 kj/kg at 20°C 2418.6 k/kg at 35C Vapor pressure of water: 17.54 mm Hg at 20°C. 35C is 42.18 mm Hg.
Acertain superinsulation material having a thermal conductivity of 2*10^-4 W/m*^ C is used to insulate a tank of liquid nitrogen that is maintained at - 196 degrees * C : 199 kJ is required to vaporize each kilogram mass of nitrogen at this temperature. Assuming that the tank is a sphere having an inner diameter (ID) of 0.52 m, estimate the amount of nitrogen vaporized per day for an insulation thickness of 2.5 cm and an ambient temperature of 21 degrees * C . Assume that the outer temperature of the insulation is 21 degrees * C .
What is the final temperature when a 200-gram copper with specific heat of 0.1 cal/gm-°C is at a temperature of 80°C when it is added to a 200 gram of water at 20°C that is held in a 50-gram aluminum cup having a specific heat of 0.22 cal/gm-°C. COMPLETE FBD SOLUTION AND REQUIREMENTS PS. THIS IS A HEAT TRANSFER PROBLEM