Chemical Equipment Sizing

Sizing of chemical equipment? Well , the common equipment required to process oil & gas, chemical & petrochemical such as Reactor, Distillation Column, Pressure Vessel/Gas Scrubber, Compressor, Pump.

How to design Reactor?
1.Perform calculation based on rate of reaction to obtain volume of reactor.
2.Key in the  data into simulation software (Hysis,Icon).
3.Determine operating parameter (e:g pressure & temperature).
4.Perform sizing calculation.
5.Perform mechanical design
6.Proced with costing , technical drawing and lastly start up & shut down procedure

How to design Distillation Column?
Distillation column separates the liquid mixtures into their components. Upper section is called rectifying section and lower one is called stripping section. The liquid having lower boiling point is obtained as a bottom 
product and the liquid of a higher boiling point obtained as a top product.

1.Choosing tray column or packed column. Tray is the common one as it is designed to handle wider range of liquid & gas flowrate, easier to clean as in the case of fouling.
2.Choosing tray either bubble cap (expensive), sieve trays (cheapest) or valve plates based on cost , efficiency and pressure drop.
3.Conduct simulation (Hysis, Icon), Select operating condition.
4.Deteremine number of equilibrium stages (Fenske Equation,MCCabe thiele method, VLE).
5. Sizing the internal column (Diameter, no of real stages).
6. Perform mechanical design (vessel & internal fittings,head, closure,shell thickness, nozzle)
7. Proced with costing , technical drawing and lastly start up & shut down procedure .

How to design Gas Scrubber?
1. Let say the input of inlet contained natural gas & water.The vessel will separate these 2 component by forces usually gravity.
2.Usually demister pad inside gas scrubber is used to improve efficiency of separation where it is use to resist the droplet of water that are not fully vapourized to enter top product.
3. Calculate the settling velocity,
4.Calculate the diameter and total height.
5. Perform mechanical design (Nozzle)

How to design heat exchanger?
1. HE is used to transfer heat between hot and cold stream.
2. Tube side preferable for fluid that has high presure, high temperature.Fluid having more corrosive nature and higher fouling factor is passed through tube side because we can easily replace the tube after maintenance but if the shell get corroded it will be more economical to replace or maintain it.
3. Cooling water will enter tube side while reactor effluent enter shell side.
4.Determine physical properties of tube and shell side (temperature, specific heat,thermal conductivity,density, viscosity)
5.Calculate heat duty Q=mcT
6. Calculate heat transfer area U=Q/AT
7. Calculate tube side velocity, shell diamter



How to design Compressor ?
1. Compressor is use to compresses gas from 1 point to another point.
2. Calculate pressure,volume & work done.
3. Calculate compression ratio.
4. Calculate power required 7 electrical power.

The day when you fuck up

Interviewer asked : How to size a CSTR?
I guess lots of fresh graduate blur, empty like they never had a class for reaction engineering then they fuck up with "i guess" answer..haha...Lupe wei sampai CSTR tu ak xley nk byg ...
Dah la yg interview tu general manager or ceo..shit happen bro...
Seorg Chemical Engineering student yg dah design equipment dalam final year project, kena r tau CSTR ade fundamental sizing parameter.

Basic knowledge- Reactor usually ade 2 types. Tubular and Stirred tank reactor.Reactor yg ideal ialah reactor yg has stirring yg effiecient, contents always in uniform composition and temperature throughout.Tubular reactor ni , reactant yakni fluid di pump and move thru the tubes as plug and move parallel to the axis mcm piston or plug flow. Reaction occur as fluid travel thru the PFR.CSTR pulak fluid masuk dlm tank reactor yg ade impellar dlm masa same reactor effluent is removed.

CSTR -Steady state, continuous flow reactants & products
           -Volume CSTR represented by area in Levenspiel plot

Design stage?
1.Calculate volume by finding rate of reaction (1st order, 2nd order etc)
2. Calculate power consumed
3. Calculate mechanical design (thickness of shell, impellar design, diameter impeller) material of construction and insulation of selection)
4. Choose reactor type yg bole bg desired convesion n yield

              CSTR-Tau basic ok la..Reactor ni penting..Act as the heart of a process.

Additional Info :
CSTR
1. Divide volume of tank with average volumetric flowrate equal to residence time
2. Flowrate in is equal to mass flowrate out.
PFR
1.As the concentrations of the reagents decrease and the concentration of the product(s) increases the reaction rate slows
2. Plug flow : No upstream & downstream mixing
3. e:g fixed bed reactor

Yeah..1st time aku create blog..mmg noob..sbb tu gamba tutup muka skit...So blog ni khas utk share aku nyer experience since abis study dec 2012 aritu..From UTP, taking chemical engineering...So aku akan update pasal job opening, interview and everything related to oil and gas industry..acewah....So kire skang aku still jobless..and aku x kategorikan diri aku as fresh grad pun sbb bru 2 bulan abis stdy otak da mcm najwa latif nyer lagu tu..kosong kosongggg...yg ak taw bnd fresh ni mcm ikan sotong ketam yg nk buat stimbot tu..haha..