Discussion
Fuel of calorific value \( 42 \) MJ/kg is burnt at \( 14 \) kg per hour in a dryer evaporating \( 190 \) kg of water per hour. The specific energy consumption is
Answer: A
Correct answer: 3.09 MJ per kg of water
The heat supplied per hour is the fuel rate times its calorific value, and the specific energy consumption divides that by the water evaporated:
\[ Q = 42 \times 14 = 588\ \mathrm{MJ/h} \]
\[ SEC = \frac{588}{190} = 3.09\ \mathrm{MJ\ per\ kg\ of\ water} \]
Against the latent heat of \( 2.3 \) MJ/kg this corresponds to an efficiency of about 74 per cent, which is good for a direct-fired dryer. The distractor \( 2.30 \) is the latent heat itself - the theoretical floor, not the actual consumption.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development