SMOKE TUBE & WATER TUBE BOILER


SMOKE TUBE BOILERS   


      
     

1. Smoke tube boilers have smoke or fire flowing through inside the tubes and  water surrounds these tubes. 

2. Generally used where there is less demand of superheated steam.  
     
3. Smoke tube boilers are heavier as compared to water tube boilers. 

4. Its efficiency is low and can generate low or medium pressure steam only. 

5. These are having less efficient combustion. 

6. The threat of thermal stress is high because water circulation is poor. 

7. It occupies more space and generation of steam takes longer time. 

8. Furnace and shell of this type of boiler is sometimes subjected to deformation and this may result in the hazardous event. 

9. Tubes of this type of boiler are generally having the larger diameter and hence they are joined with the help of welding only. 

10. Quality of water used and its treatment is less stringent.

WATER TUBE BOILER   


 

1. Water tube boilers have water flowing inside the tubes and heat surrounds these tubes. 

2. Generally used where superheated steam is required e.g for turbines.

3. Light weight construction 

4. Efficiency much higher than smoke tube boilers and can generate higher pressure steam. 

5. Efficiency of combustion is better (Eff. > 85%). 

6. Thermal stresses are less as the water circulation is very good inside the tubes. 

7. Steam generation takes place in short period and consumes less space. 

8. Tubes are of smaller diameter and interference method is generally used to fit them. 

9. Water level must be maintained up to appropriate level during firing to avoid damage & continuous steam generation

10. Quality of feed water and its chemical treatment used is always higher than smoke tube boiler.

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