A gas-vapor mixture has wet-bulb and dry-bulb temperatures of 25°C and 30°C. If heated to 45°C isobarically, the resulting wet-bulb temperature will be ______________ °C?
Show answer Hide answer
Answer: B. > 25
Explanation
Isobaric heating of an unsaturated mixture adds sensible heat and raises total system enthalpy. The thermodynamic wet-bulb temperature increases in response to the higher sensible gas temperature. Psychrometric relations show that heating air without adding moisture shifts wet-bulb upward. Isobaric processes occur at a constant total system pressure usually equal to atmosphere. Wet-bulb temperature reflects the dynamic equilibrium between sensible heat and latent heat transfer. Dry bulb temperature measures ambient air temperature without accounting for moisture content.
HVAC engineers analyze isobaric heating coils using psychrometric charts for building comfort. Industrial drying operations involve heating air streams which changes their psychrometric properties. Understanding humidity parameter changes prevents condensation issues inside processing equipment ducts. Remaining at twenty-five degrees ignores the sensible heat addition during the heating process. A lower wet-bulb temperature would imply cooling rather than heating the gas mixture. Negative temperatures are physically impossible for standard ambient air heating scenarios.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Under steady-state equimolal counter-diffusion of two gases A and B, the value of NA/(NA + NB) is____________?
Show answer Hide answer
Answer: B. ∞
Equimolal counter-diffusion means that molar fluxes of gases A and B are equal magnitude opposites. Adding equal and opposite fluxes together results in a net zero denominator value. Dividing a finite flux by a vanishing...
Q2. Although adsorption and desorption isotherms theoretically overlap, adsorption hysteresis often occurs where the desorption equilibrium pressure is ______________ the adsorption pressure?
Show answer Hide answer
Answer: A. Lower than
Adsorption hysteresis loop geometry inherently places the desorption path at lower pressures. Capillary condensation within mesopores retains adsorbate molecules more strongly during the removal phase. Equilibrium pressu...
Q3. To attain high distillation tray efficiency, operators must ensure___________________?
Show answer Hide answer
Answer: A. Interfacial surface between liquid and gas phase should be large
Tray efficiency improves when vapor and liquid have extensive contact area for mass transfer. A large interfacial surface area accelerates the rate of component transfer between phases. Maximizing contact area ensures th...
Q4. An air-vapor mixture exhibits wet and dry bulb temperatures of 25°C and 30°C. Upon isobaric heating to 45°C, the wet-bulb temperature becomes ______________ °C ?
Show answer Hide answer
Answer: B. > 25
Adding thermal energy isobarically to an air-vapor mixture increases its overall system enthalpy. The wet-bulb temperature rises correspondingly as sensible heat is transferred to the fluid. Psychrometric principles dict...
Q5. Extraction solvents should avoid high latent heats of vaporization because ______________________?
Show answer Hide answer
Answer: C. Its recovery cost by distillation may be prohibitively high
High latent heats mean solvents require immense thermal energy input to vaporize during separation. Solvent recovery via distillation becomes economically unviable due to exorbitant reboiler duty requirements. Excessive...
Q6. Petroleum refinery distillation columns of 10-12 ft diameter typically maintain tray spacing around _____________ inches?
Show answer Hide answer
Answer: B. 30
Standard industrial practice dictates specific tray spacings to prevent liquid entrainment between stages. A tray spacing of thirty inches provides sufficient disengagement height for vapor-liquid disengagement. Design g...