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