How does the volumetric capacity of an induced draft fan compare to a forced draft fan in boiler setups__________________?
Show answer Hide answer
Answer: B. more
Explanation
Induced draft fans handle hot flue gases exiting the boiler after combustion is complete. High temperatures cause gases to expand significantly according to ideal gas laws, increasing volumetric flow. Consequently, an induced draft fan requires a much larger volumetric capacity than a forced draft fan. Forced draft fans push ambient air into the combustion chamber, handling cool and dense air streams. Induced draft fans pull gases through the boiler, operating in high-temperature and low-density environments. Fan volumetric capacity is measured in actual cubic meters per unit time under operating conditions.
Power plant engineers size draft fans carefully to maintain balanced furnace pressure and proper airflow. Handling hot flue gases requires specialized high-temperature fan materials and robust blade construction. Draft system efficiency directly impacts overall boiler performance and fuel consumption rates. Option A incorrectly assumes equal volumetric capacities despite the major temperature difference in gas streams. Option C reverses the volumetric requirement by suggesting induced fans need less capacity than forced fans. Option D incorrectly links fan capacity variability to boiler physical size rather than gas temperature physics.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. What is the duration of the ignition delay period in petrol engines__________________?
Show answer Hide answer
Answer: B. 0.002 see
The ignition delay period in spark-ignition petrol engines is extremely brief, typically lasting around zero point zero zero two seconds. This tiny time interval covers the chemical and physical preparation stages occurr...
Q2. What happens to dry saturated high-pressure steam (150-200 kg/cm2) when throttled down to atmospheric pressure_______________?
Show answer Hide answer
Answer: A. wet
Throttling is an isenthalpic process where high-pressure steam expands through a narrow valve or orifice without doing external work. For high-pressure dry saturated steam in the range of 150 to 200 kg/cm2, the constant...
Q3. What is the typical overall thermal efficiency range of internal combustion engines_________________?
Show answer Hide answer
Answer: D. 30-35%
Standard internal combustion engines typically achieve an overall thermal efficiency in the range of 30% to 35%. Thermodynamic losses through exhaust gases, cooling systems, and mechanical friction limit practical engine...
Q4. What is the primary purpose of incorporating an economizer in boiler systems _______________________?
Show answer Hide answer
Answer: A. increase thermal efficiency of boiler
An economizer preheats boiler feed water using waste heat from exhaust flue gases, which directly increases thermal efficiency. Recovering thermal energy that would otherwise escape up the chimney reduces the total fuel...
Q5. What condition does dry saturated low-pressure steam (5-10 kg/cm2) reach when throttled to atmospheric pressure________________?
Show answer Hide answer
Answer: B. superheated
Throttling low-pressure dry saturated steam from 5 to 10 kg/cm2 down to atmospheric pressure is an isenthalpic expansion process. At these lower initial pressures, the constant enthalpy line crosses into the region of th...
Q6. What is the equivalent evaporation of a steam generator used to evaluate _________________?
Show answer Hide answer
Answer: E. any type of boilers operating under any conditions
Equivalent evaporation provides a standardized baseline metric used to compare the performance of any type of boiler operating under arbitrary conditions. It converts actual steam generation rates into an equivalent mass...