2. OUTLINE
 Introduction
 What is steam
 Types of steam
 Heat exchanger
 Steam in heat exchanger
 Basic ways to improve heat transfer
 Ways to improve steam efficiency
 Problems in steam equipment
 Conclusions
 References

3. INTRODUCTION
 The dramatic jump in petroleum prices over the recent
years has created much impetus to reduce operating costs
at chemical process plants.
 The plant’s steam resource is often a primary provider of
heat to a process.
 So using steam efficiently helps reducing operation cost
thereby generating savings.

4. STEAM
 Steam is the gas formed when water passes from
the liquid to the gaseous state
 Steam is one of the most common and effective
heat transfer mediums used in industry
 They are mainly used in heat exchangers,
turbines, strippers, and chemical reaction vessels

5. TYPES OF STEAM
 WET STEAM
 Wet steam applies to steam when a portion of its water
molecules have given up their energy (latent heat) and
condense to form tiny water droplets
 Also known as saturated steam
 Mixture of water in the liquid state (tiny droplets) and
gaseous state (steam)

6. DRY STEAM
Dry steam applies to steam when all its water molecules
remain in the gaseous state
Known as superheated steam
It's a transparent gas
Superheated steam and liquid water cannot coexist
under thermodynamic equilibrium

7. WET STEAM VS. DRY STEAM
WET STEAM
Rapid, even heating through latent heat transfer
High heat transfer coefficient
Originates from water
Used for heating, cooking, drying or other procedures in
industries
DRY STEAM
Low heat transfer coefficient
Temperature may be extremely high
Sensible heat used to transfer heat
Exclusively used in turbines

8. HEAT EXCHANGER
 Heat exchanger an equipment built for efficient heat transfer from
one medium to another
 The media are separated by a solid wall so that they never mix
 They are widely used in refrigeration, air conditioning, power plants,
chemical plants, petrochemical plants, petroleum refineries, and
natural gas processing
counter-current and co-current flow

9. STEAM IN HEAT EXCHANGER
Saturated steam is used in heat exchanger because it has high
heat transfer coefficient
Heat transfer with saturated steam utilizes the latent heat of
steam, releasing a large amount of energy as it condenses
Provision is made for condensate recovery

10. BASIC WAYS TO IMPROVE
HEAT TRANSFER
Temperature difference between the steam and process fluid
should be high
Using saturated steam instead of superheated steam
improves efficiency and minimizes operation cost
Higher the flow rate, higher will be the heat transfer
High conductivity of heat exchanger material helps in better
heat transfer
Larger the surface area of conducting interfaces, greater the
heat transfer rate

11. WAYS TO IMPROVE STEAM
EFFICIENCY
STEAM TRAPS
Steam traps are a type of automatic valve that filters out
condensate (condensed steam) and non-condensable gases
such as air without letting steam escape
They need to be monitored for leakage and other faults
Replacing faulty traps minimizes loss of steam and improves
efficiency

12. CONDENSATE RECOVERY
The condensate from traps can be returned to the boiler
This helps in reducing boiler fuel needs
Reducing boiler fuel needs through condensate recovery leads
to less air pollution by lowering CO2, NOx and SOx emissions
INSULATING STEAM SYSTEM
Despite high cost, insulation reduces heat loss
Helps save energy
MONITORING LEAKS
Checking the steam distribution lines and valves for leakage
and fixing them could save energy and enhance efficiency
STEAM METERING
Steam metering provides accurate steam usage statistics
It can be a useful troubleshooting tool

13. PROBLEMS IN STEAM
EQUIPMENT
WATER HAMMER (STEAM HAMMER)
Steam first supplied to steam distribution piping or steam-
using equipment, a metallic and repetitive 'bang, bang, bang',
or even sometimes a violent 'boom' accompanied by vibration
may be heard
Caused by high levels of accumulated condensate inside the
equipment

14. Water hammer causes a momentary abrupt pressure change
of over 10MPa inside the piping
Can severely damage piping and equipment

15. FIXING IT
Rapid discharge of condensate is critical from a preventative
maintenance standpoint
The speed of condensate discharge combined with how
smoothly the process occurs are two extremely important
factors in the fight against water hammer in steam-using
equipment
Proper design and orientation of the equipment

16. STALL
Occurs when the necessary pressure differential across a
drainage device such as a trap becomes negative
Condensate is no longer discharged from the drainage device
and instead pools inside the heat exchanger
Linked to the following problems - ruptured heaters, water
hammer, uneven heating temperatures

17. FIXING IT
Increasing trap inlet (primary) pressure
Reducing trap outlet (secondary) pressure

18. CONCLUSIONS
By proper use of steam, operational cost can be minimized
and high efficiency is achieved
Condensate recovery and recycling back to boiler helps
reducing boiler fuel needs thereby minimizing pollution
Damage to equipment can be averted by properly regulating
the steam
Using steam intelligently lowers carbon emission

19. REFERENCES
http://www.tlv.com/global/SG/steam-theory
James R. Risko, optimize the Entire Steam System, CEP June
2008, 31-32
James R. Risko, Understanding Steam Traps, CEP Feb 2011, 21-
26
James R. Risko, Handle Steam More Intelligently, CHEMICAL
ENGINEERING www.che.com Nov 2006, 44-48