Sorry for the little delay. Thanks Mr. Johnny for your kind response, advice and time.
Yes although I have explained my analysis, I am also not that convinced that skidding has taken place in the outer bearing. The raceways do not have a polished track. However, fact of the matter is that every...
Because from the bearing failure of the outer bearing, it appears that the cage and balls have shifted towards the wider flange side of the inner ring. (In back to back configuration, wider flange of the inner ring is always pointing towards the coupling side). Since the the inner rings are...
Hi!!
We have a single stge centrifugal pump (OH-2) wih Kero (Sp Gr - 0.71, voscocity : < 1 cP) as service in our CDU unit with a pumping temp of 200 degC, capacity : 56.5 m3/hr and a head of 81 mts. Same is the BEP condition.
MOCs : Shaft-AISI 4140, Impeller and casing-CS, Wear rings-12% Cr...
Dear SVKD !!
I do not know why you are going through a dial indicator to know pipe strain.
I can comment on pulsation study though :-
There are parties who carries out pulsation study of recip machines by considering gas effects and vibrations.
For a reciprocating compressor, it is always a...
For our wash water applications in HDT unit, we are using single acting triplex reciprocating pumps (Make: Pernoni, Model:Titano 3130); discharge pressure : 160 bar, but you have to ensure a full flooded suction. So far we are not facing any problems. Periodic preventive maintenance is...
Thanks EP and strong!!! Nice to see all your comments and analysis on the subject matter. Good lesions learned for me.
In simple terms, what I could understand is that as per strong's view, coupling failure might be due to torque transients during startup against reverse rotation and torsional...
Yes, I did compare.
failed fan coupling has a bowed or bulged out shim pack but the other fan is OK (Shim pack clamped together without any bow/bulging). Will soon share the photos.
What a fantastic advice. I am just loving it. Thanks a lot !! EC
I have seen some patterns (after taking photos as suggested) similar to fig no.10 of your upload.
Seems that the coupling is going through torque overload as per the depicted analysis. Does this also mean that torque reversals...
The coupling does not immediately fails, last it failed on Jun'16 after running for 4 months from Feb,16. But since the fan is started against reverse rotation (discharge damper opens 1st on motor start initiative) and back pressure generated by the already running fan. But as per present flow...
Thanks to everyone for such wonderful explanations & knowledge sharing.
We have already started thinking in the line of starting the motor by keeping damper closed & once speed reaches its full, we will be opening the damper full. (For this, we will have to reverse the interlock; that is OK)...
Thanks for the responses & valuable inputs.
Reply of Strong's questions :
a) There is no soft starter. Motor is a 6 pole, 3 phase, 415V, 75KW,124 FLA, 980 rpm; Make - Crompton Greaves; Frame-E315M and starting mode - DOL, Motor Starting torgue : 200% of Full load torque. Also, Fans full load...
In our DCU plant, we have 2 nos of FD fans (identical) for supplying combustion air to the burners with the following data :
Flow : 10.896 m3/sec, Static pressure :4700 pa (479 MMWC), Rated power : 61.25 KW
Temp : 35C, RPM : 980, Motor rating : 75KW. Impeller type : Backward curved.
Each fan...
Thanks Don & George for your valuable comments.
Rightly pointed out that the fan is not supposed to go under surge considering such low pressure levels.
Also, alignment was done during last shutdown, reported OK. No abnormality is reported from vibration checks also (before the failure)...
In our DCU plant, we have 2 nos of FD fans (identical) for supplying combustion air to the burners with the following data :
Flow : 10.896 m3/sec, Static pressure :4700 pa (479 MMWC), Rated power : 61.25 KW
Temp : 35C, RPM : 980, Motor rating : 75KW. Impeller type : Backward curved.
Each fan...
