1. STEAM GENERATOR
 What is a boiler?
 Diff between boiler and steam generator
 Applications
 Main parts: Shell, firebox , smoke box…
 Classification of Boilers

2. Classification
1. As per flow medium inside tube
2. Location of shell axis
3. Furnace position
4. Water circulation
5. Draft
6. Pressure
7. Mobility
8. Number of tubes
9. Type of fuel used

3. Essentials
 Light and compact
 Easy to maintain, it should capable of
generating steam of desire Quality, pr, temp
 Must be as per IBR (Indian Boiler Regulation)
 Low cost (initial and operating)
 Able to absorb the fluctuations in the load
 Quick starting , easy access of required air….

4. Specification
 Shell Diameter and length
 Rate of steam generation
 Pressure
 Heating surface area
 No of tubes/drum
 Type of boiler…

5. Fire tube
 Costly, more space
 Low pressure (upto 25 bar)
 Slow steaming rate
 Scale is not Problem
 Large reserve capacity
 Shell bursting is disastrous
 Application(locomotive, road-rollers..)
 Example(Lancashire, Cochran, Cornish,
locomotive)

6. Water Tube
 Less costly, more compact, high maintenance
 High Pressure (upto 300 bar)
 Steam can be raised quickly
 Scale deposition is a Problem
 Small Reserve capacity
 Tube bursting causes less damage
 Application(Power plants and Ships)
 Example (Babcock and Wilcox)

7. TYPES OF THE BOILERS
 Vertical Boiler
 Cochran Boiler
 Locomotive Boiler
 Babcock and Wilcox Boiler
 Lancashire Boiler

8. IBR and Non IBR Boilers
 Boilers generating steam at working
pressure below 10 bar and having water
storage capacity less than 22.75 liters are
called Non IBR boilers and are exempted
from observing Indian Boiler Act.

9. IBR Mountings
1. Safety valves 2 Nos. (S)
2. Water Level Indicator 2 Nos. (C)
3. Pressure Gauge (C)
4. Steam Stop valve (c)
5. Feed check valve(C)
6. Blow off Cock (C)
7. Manhole (I)
8. Mud hole (I)
9. Fusible Plug (S)

10. Boiler Selection
 Quality of steam
 Rate
 Temperature
 Pressure
 Availability of floor space
 Availability of feed water
 Cost
 Type of load : steady or fluctuating

11. Boiler Mountings
 Safety valves
 Pressure gauge
 Water level indicator
 Steam stop valve
 Feed check valve
 Blow – off – cock
 Fusible plug

12. Accessories
 Super heater
 Air Preheater
 Economiser
 Injector
 Feed Pump

13. Draft
 Characteristics of draft system:
1. It should produce flow of air to meet the
oxygen requirement
2. Control the flow of air at different loads
3. Discharge of the flue gases at high level
4. Sufficient pr difference to overcome the
resistance of boiler passage

14. Types of draft
 Natural draft: simple, chip, suitable for
small capacity boilers, controlled by damper
 Artificial draft: large capacity boilers,
reliable, easy to control, requires mech
power
1. Forced draft: fan provided at the inlet
2. Induced draft: fan provided at the exit
3. Balanced draft: combination of 1 and 2.