Exhaust gases from a wire processing oven are discharged into a tall stack, and the gas and stack surface temperatures at the outlet of the stack must be estimated. Knowledge of the outlet gas temperature
(a) Consider conditions for which the ambient air temperature and wind velocity are 4°C and 5 m/s.respectively. Approximating the thermophysicalproperties of the gas as those of atmospheric air,estimate the outlet gas and stack surface temperatures for the given conditions.
(b) The gas outlet temperature is sensitive to variationsin the ambient air temperature and wind velocity.For
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Fundamentals of Heat and Mass Transfer
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- 8.2 From its definition and from the property values in Appendix 2, Table 13, calculate the coefficient of thermal expansion, , for saturated water at 403 K. Then compare your results with the value in the table.arrow_forwarda film-type condenser consists of a packed bed of 3-cm diameter spheres with a voidage of 35%. water sprayed onto the bed at 60oC is used to condense steam entering at the base at a saturation temperature of 100oC. How deep must the bed be to ensure complete condensation of the steam, and what is the outlet temperature of the water? (Use water properties based on the mean of the inlet and outlet water temperatures, and iterate if necessary)arrow_forwardSaturated, pure steam at a temperature of 170 °C condenses on the outer surface of a vertical tube of outer diameter 2 cm and length 1.5 m. The tube surface is maintained at a uniform temperature of 150 °C. Calculate: a) the local film condensation heat-transfer coefficient at the bottom of the tube.arrow_forward
- Ethylene glycol with a mass flow rate of 0.01 kg / sec flows in a thin-walled pipe with a diameter of 3 mm. The pipe is in the form of a serpentine, and was lifted into a well-mixed water bath at 25 ° C. Calculate the heat transfer and pipe length required for the fluid to enter the pipe at 85 ° C and exit at 35 ° C?arrow_forwardQuestion 3 This question requires the use of the steam property tables (Rogers and Mayhew) uploaded on QM+ exam section. All properties should be evaluated at the temperature of the steam. Saturated, pure steam at a temperature of 170 °C condenses on the outer surface of a vertical tube of outer diameter 2 cm and length 1.5 m. The tube surface is maintained at a uniform temperature of 150 °C. Calculate: a) the local film condensation heat-transfer coefficient at the bottom of the tube. b) the average condensation heat-transfer coefficient over the entire length of the tube. c) the total condensation rate at the tube surface.arrow_forward*** 32. A double-chambered container contains one mole of helium in one of its 1000 cm³ Pull to volume chambers. The container is well-insulated, and of low specific heat, so that no appre- remove ciable heat is added to the gas during the process we describe. The gas is initially at a tempera- ture of 300 K and a pressure of 1 atmosphere. The partition between the two chambers is then quickly raised, and the gas expands freely to fill the entire container. Whenever a monatomic gas like helium doubles its volume adiabatically like this, the pressure in the gas will drop to 0.315 of what it was before (for reasons that we did not explain in this chapter), so the final 1000 cm3 1000 cm³ pressure of the expanded gas will be 0.315 atmospheres. a) What is the temperature of the gas after the expansion? b) What is the change in the internal energy of the gas? c) How much heat is added to the gas? [Hint: Maybe read the problem again.] d) How much work is done by the gas as it expands? [Hint:…arrow_forward
- The condenser of a steam power plant consists of AISI 302 Stainless steel tubes, each with outer and inner diameters of 35 mm and 30 mm, respectively. Saturated steam at 0.135 bar condenses on the outer surface of the tube, while water at a mean temperature of 295 K is in fully developed flow through the tube (you can assume that 295 K is the mean temperature in the axial direction of the tube (e.g. along its length) or you may assume that the inlet water temperature is 295 K). For a water mass flow rate of 0.22 kg/s, what is the outer surface temperature of the tube and the rates of heat transfer and steam condensation per unit tube length? As an approximation you may evaluate the properties of the liquid film at the saturation temperature.arrow_forwardOnly answer if you are 100% sure otherwise i will downvote... An ASTM B75 copper tube sheathes a heating element that is used to boil water at 1254 kPa. The copper tube is immersed horizontally in the water, and its surface is polished. The tube diameter and length are 5 mm and 9.5 cm, respectively. The maximum use temperature for ASTM B75 copper tube is 204°C. Determine the highest evaporation rate of water that can be achieved by the heater without heating the tube surface above the maximum use temperature. Use the property tables to calculate the properties of water at saturation temperature. The surface tension 0 at 190°C is 0.03995 N/m. Also, Csf 0.0130 and 10 for the boiling water on a polished copper surface. The highest evaporation rate of water is g/s?arrow_forwardA horizontal pipe of 100-mm-diamter and 1 m long with a surface temperature of 94 ℃ is used to condense saturated steam at 1 atm. Determine the heat transfer rate for the condensation process. Properties of Water, vapor (1 atm): Tsat = 100℃, ρv = 0.596 kg/m3, hfg = 2257 kJ/kg;Water, liquid (Tf = 370K): ρl = 960.6 kg/m3, Cpl = 4214 J/kg.K, μl = 289*10^-6 N.s/m2, kl = 0.679 W/m.K. Select one: a. 28567 W b. 18254 W c. 19076 W d. 22552 Warrow_forward
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- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning