Translate

Technical Interview Questions -2

Technical Interview Questions -1 contains chemical plant interview questions frequently asked in chemical plant interview questions

Technical Interview Questions -1


Blog Contents
1. What is dew point ? Why it is important in instrument air?
2. What is difference between PFD and P&ID?
3. What is floculation & Coagulation?
4. What is difference between Bubble point and Boiling Point? What is Different between dew point & Freezing?
5. What is Unit operation & Unit process?
6. What is molecular sieve?
7. What is definition of Pervaporation?
8. What is RO – Reverse Osmosis?
9. How to use Gate Valve, Globe Valve & Ball valve?
10. Why cyclone separator has tangential entry?

1. What is dew point ? Why it is important in instrument air?

Dew point is a temperature beyond this there is no vapour form of fluid exists in air. When air is condensed below its dew point then all moisture present in air will be condensate and air becomes completely dry.

Instrument air used in costly instruments to operate. If we use moist air then it will harm to devices. This is the reason dew point is maintained in air around -40°C

[ads id="ads1"]

2. What is difference between PFD and P&ID?

PFD - Process flow diagram.
PFD - Process flow diagram.
PFD - Process flow diagram.
P&ID - Process and Instrument diagram.
P&ID - Process and Instrument diagram.
P&ID - Process and Instrument diagram.


PFD is showing process flow diagram while P&ID is showing Valves, Pumps, Compressors and Instruments.

[ads id="ads1"]

3. What is floculation & Coagulation?

Floculation

  • Floculation is physical operation.
  • Any Fluid has solid waste particles or sludge then flocal agent convert into lump by making low to medium polymer chain and settle it down.
  • Examples - METAC, Megnafloc

Coagulation

  • Coagulation is chemical process.
  • It is reacting with waste chemically with poly ionic materials
  • Example - Aluminium sulphate, Aluminium Chloride, Hydrochloric acid, Alum,
[ads id="ads1"]

4. What is difference between Bubble point and Boiling Point? What is Different between dew point & Freezing?

Definitions

Dew Point -

It is the temperature where first bubble of vapour formed in liquid.

When we are boiling water at 100℃ we can see vapour formed from bottom from where heat is applied. when first bubble is generated it is bubble point of water.

Boiling  Point - 

It is a temperature at which the vapour pressure of a liquid at which the vapour pressure of the liquid is equal to atmospheric pressure.

When temperature increased and at specific temperature at which Vapour generated by fluid is 1 atmospheric pressure
If we have binary fluid mixture and we are increasing temperature then Boiling point of less volatile component is change with respect to High volatile component.

When Fluid mixture initial boiling is started then less volatile fluid start vaporizing is started and in more volatile liquid its vaporize later.
Now we see Dew point & Freezing point of fluid

Dew point

Dew point of fluid is the temperature below that there is no vapour present in atmosphere

Example - Dew point of water is 16℃. There is no water vapour present below 16℃

Calculate Dew point - Calculate now

Freezing point

Freezing point of fluid is temperature at which liquid phase is completely convert into solid phase.
Freezing point of water is 0℃

[ads id="ads1"]

5. What is Unit operation & Unit process?

Unit Operation - 

Unit Operation is defined as operation in which mass & concentration of  component is changed from inlet to outlet with external sources

Example - Distillation Drying, Evaporation, Drying, Mixing, Crystallization, Leaching, in all this mass and concentration of components are changed but no change in  chemical

Unit Process - 

Unit Process is defined as when two chemicals proceed and formed another chemical product.

Example - Nitration, Halogenation, Hydrogenation, Amination, Sulphonation, Chlorination in which products are chemically changed

[ads id="ads1"]

6. What is molecular sieve?

Molecular sieve means a solid micro porous alumina silicate with uniform pore geometry it is called as zeolite

What is molecular sieve?

[ads id="ads1"]

7. What is definition of Pervaporation?

  • It is membrane separation technique for liquid-liquid separation technique.
  • Permeate liquid is brought in contact to vacuum and extracted as vapour

8. What is RO – Reverse Osmosis?

  • Solution is subjected to Membrane.
  • Membrane allow to pass solvent from one portion to another
  • This is method used to separate water.
[ads id="ads1"]

9.How to use Gate Valve, Globe Valve & Ball valve?

  • Gate Valve – Fully on or off condition.
  • Globe Valve – Throttling purpose design.
  • Ball valve – Quick On or off valve.

10. Why cyclone separator has tangential entry?

  • When laden gas enters in cyclone it forms swirl.
  • This swirls separate dust and light particles.
  • If there is straight entry these swirls not form and separation doesn’t takes place.
  • This is the reason why tangential entry is in Cyclone separator.
[ads id="ads1"]

Watch video in Hindi -


Read more about "Technical Interview Questions" from Industrial Guide - Click here

Important links
Wikipedia -
Read more on Chemedu

Photo credits [ Labeled for Reuse ]
Wikipedia

Thanks for reading -
Naitik Patel
Industrial Guide

Share this blog with your friends from here 👇

Previous Post Next Post