Description of mechanical seal, types of mechanicla seal

Types of mechanical seal

1. Mechanical S eal Abdullah Al Mamun B.Sc in Engg . (Mechanical) Sub-Divisional Engineer (MMD) Sirajganj 225MW CCPP (Unit-01)

2. M echanical S eal Mechanical Seal is a part used to achieve sealing of the rotating shaft of the pump and Compressor as its entry or exit to the casing. Abdullah Al Mamun, SDE, MMD, S1 2

3. Components of Mechanical Seal Abdullah Al Mamun, SDE, MMD, S1 3 Stationary face Rotary parts & O Ring Spring

4. Working principle of mechanical Seal Stationary Part Rotary Part

5. Working principle of mechanical Seal Stationary Part Rotary Part Figure showing possible path of water flow in a mechanical seal

6. Working principle of mechanical Seal Stationary Part Rotary Part Mirror polished faces Rubber O-ring Spring & Fluid force The seal faces are pushed together using a combination of hydraulic force from the sealed fluid and spring force from the seal design. The sealing face is as mirror polish. So, water (fluid) can not pass through the seal face. There has O-ring (secondary sealing element) in the rotating part and prevent water passing between shaft and rotating part.

7. Mechanical seal Abdullah Al Mamun, SDE, MMD, S1 7

8. Abdullah Al Mamun, SDE, MMD, S1 8

9. Single spring/ multi spring mechanical seal Abdullah Al Mamun, SDE, MMD, S1 9

10. Single -Spring Mechanical Seal Moves axial along with shaft Pusher Type Seal Unbalanced Seal design Cheap Up to 10 bar pressure Large misalignment allowed Mono directional Not suitable for sticking product Abdullah Al Mamun, SDE, MMD, S1 10

11. Multi -Spring Mechanical Seal Pusher type design Robust Construction Withstand sticking of seal faces Bi-Directional Technical skill is required to install . Abdullah Al Mamun, SDE, MMD, S1 11

12. Balanced/ Unbalanced mechanical seal Abdullah Al Mamun, SDE, MMD, S1 12

13. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 13 Spring Rotary ring Stationary Ring

14. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 14 F (Spring) Closing Force= F (Spring) +?

15. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 15 F (Spring) P P Closing Force = F (Spring) + F ( Press)

16. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 16 F (Spring) P P Closing Force = F (Spring) + F ( Press) F ( Press )= Fluid pressure * Area

17. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 17 F (Spring) P Closing Force = F (Spring) + F ( Press) Opening force=  

18. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 18 F (Spring) P Closing Force = F (Spring) + F (Press) Opening force=   P= 10 Kg/   Area= 6   Closing Force, Fc= 10 Kg/ x 6 = 60 Kg   Opening Force, Fo = x 6  

19. Unbalanced Seal Abdullah Al Mamun, SDE, MMD, S1 19 F (Spring) Closing Force = F (Spring) + F (Press) Opening force=   P= 10 Kg/ Area= 6   Closing Force, Fc= 10 Kg/ x 6 = 60 Kg   Opening Force, Fo = x 6   60 Kg 30 Kg

20. B alanced Seal Abdullah Al Mamun, SDE, MMD, S1 20 F (Spring) P= 10 Kg/ Area= 6   Closing Force, Fc= 10 Kg/ x 6 = 60 Kg   Opening Force, Fo = x 1   60 Kg 6 0 Kg Area= 12   For balance seal Closing Force = Opening Force

21. Balanced Seal Specially for high pressure application (more than 10 kg/cm2) Less heat generated across the seal face Seal life is more. Abdullah Al Mamun, SDE, MMD, S1 21 H75/48- G9 ( EgleBurgmann )

22. Abdullah Al Mamun, SDE, MMD, S1 22 Pusher/ Non-Pusher Mechanical seal

23. Pusher/Non Pusher Seal Abdullah Al Mamun, SDE, MMD, S1 23

24. Drawback of dynamic O’ring of Pusher Seal Abdullah Al Mamun, SDE, MMD, S1 24

25. Non-Pusher Seal Abdullah Al Mamun, SDE, MMD, S1 25

26. Abdullah Al Mamun, SDE, MMD, S1 26 End of 1 st presentation………