1. Petrochemical Engineering-II
Prakriti
Lecture 2.
Unit I

2. Syllabus
Unit I
Heating of crude oil through exchangers.
Pipestill heaters,
 their types and constructional features,
 estimation of heat duty, combustion calculation and heat transfer
area in different parts in pipe still heater.
 Calculation of pressure drop and stack height

3. Designing & Optimization in
Petroleum Refining
• Petroleum refining is a major industry
• Petroleum products are most important fuels
• Petroleum are the starting point for many syntheses in the chemical
industry.
• Optimization is the process of determining the best possible way of
selecting the process scheme and fixing the unit schemes etc.

4. Heat transfer
• Basic Definitions
• Heat transfer is the science which deals with the rates of exchange
of heat between hot and cold bodies called as source and receiver.
• Process heat transfer deals with the rates of heat exchange as
they occur in the heat transfer equipment of the engineering and
chemical processes.
• Exchangers recover heat between two process streams.
• Heaters are used preliminary to heat process fluids.
• Coolers are employed to cool process fluids.
• Condensers are coolers whose primary purpose is the removal of
latent heat.
• Reboilers is to supply the heat requirements of a distillation process
as latent heat.

5. • Evaporator s are used for the concentration of a solution by
evaporation of water.
• Vaporizers – Evaporation of any other fluids except water.

6. Principal Types of Heat Exchanger
1. Double-pipe exchanger: the simplest type, used for cooling and
heating.
2. Shell and tube exchangers: used for all applications.
3. Plate and frame exchangers (plate heat exchangers): used for
heating and cooling.
4. Plate-fin exchangers.
5. Spiral heat exchangers.
6. Air cooled: coolers and condensers.
7. Direct contact: cooling and quenching.
8. Agitated vessels.
9. Fired heaters.

7. Double Pipe Exchangers
Usually assembled in 12-, 15- 20ft effective length

8. • Advantages
• Easy to assemble by using standard parts
• inexpensive
• Disadvantages
• Small heat transfer area
• Requires large floor area for the battery of exchangers
• Each exchangers introduces more than 14 potential
leakage points
• High maintaince cost and time requirement

9. Shell and Tube Heat
Exchangers

10. Pipe Still Heaters
• Classification
• According to mode of heat transfer
• Open fired furnace
• Heated through medium
• According to mode of charging
• Batchwise
• Continuous
• According to mode of recovery
• Regenerative
• Recuperative
• Depending on fuel
• Combustion type
• Electric type