SL lecture 2 Flashcards
(19 cards)
What is the purpose of What-if Analysis?
To cover everything from feed to the end of the system.
Who should perform What-if Analysis?
Experienced persons.
What is required for conducting a What-if Analysis?
A flowsheet.
What are the typical timeframes for preparation of What-if Analysis for small/simple systems?
4-8 hours.
What are the typical timeframes for evaluation of What-if Analysis for complex/large systems?
1-3 days.
What is the consequence of low phosphoric acid concentration?
Unreacted NH3 carryover to the DAP storage tank and release to the work area.
What safeguard is recommended for low phosphoric acid concentration?
NH3 detector and alarm.
What is the recommended action if valve B is closed or plugged?
Periodic maintenance of NH3 detector and alarm.
What are the timeframes for evaluation of What-if/Checklist Analysis for complex/large systems?
4-7 days.
What is the purpose of What-if/Checklist Analysis?
To identify hazards, consequences, existing safeguards; to suggest alternatives for risk reduction.
What are the applications of guide words in HAZOP?
No or Not, More, Less, As well as, Part of, Reverse, Other than.
What is the primary purpose of HAZOP?
To identify and evaluate safety hazards in a process plant.
What are the typical timeframes for documentation of HAZOP for small/simple systems?
2-6 days.
What is a general deviation in HAZOP analysis?
Leak (small release), Rupture (large release), Loss of containment.
Fill in the blank: HAZOP is a systematic and critical examination of the process _______.
[vessel by vessel, line by line]
What are examples of HAZOP for procedures?
- Sampling
- Testing
- Maintenance
- Start-up
- Shutdown
- Service failure
What is the consequence of ammonia concentration in the reactor exceeding 14%?
Explosion!
What is the intention of the Air Filter in HAZOP?
To remove particles (catalyst protection).
What is the intention of the Vaporiser in HAZOP?
To convert NH3(l) to NH3(g) at 8 bar, 730 kg/h, 250°C.
