Monday, August 24, 2009

Typical Bearings Failures

Prevent over 60% of Premature Bearing Failures





Poor Fitting [16%]
About 16% of all premature bearing failures are caused by
1. Poor fitting (usually brute force ...)
2. Being unaware of the availability of the correct and proper fitting tools
3. Laziness

Individual installations may require mechanical, hydraulic or heat application methods for proper, correct and efficient dismounting or mounting.

The use of specialised tools, equipments and techniques will make the above job easier, faster and more cost effective.

These is one positive step towards long bearing life, thurs achieving maximum compressor uptime.


Poor Lubrication [36%]
About 36% of premature bearing failures are caused by incorrect specification and inadequate application of the lubrication.

Any bearings deprived of proper lubrication will long before its normal service lifespan. Bearings are usually the least accessible components of the compressors, therefore, neglected lubrication compounds the problem.

Effective lubrication, using recommended lubrication [grease, oil, coolant], Special tools, equipments, and techniques, really helps to greatly reduce downtime.


Contamination [14%]


Bearings are precision components that will not operate efficiently, unless both the bearings and its lubricants are isolated from contamination. At least 14% of all premature bearing failures are attributed to contamination.






Fatigue [34%]
Whenever compressors are overloaded, incorrectly serviced or neglected, bearings will suffer, resulting in 34% of all premature bearing failures.

Sudden or unexpected failure can be avoided, because neglected or overstressed bearings emit "early warning" signals, which can be detected and interpreted using Condition Monitoring Equipment.








Condition Monitoring Equipment
CME includes hand-held instruments, hard-wired systems and data management software for periodic or continuous monitoring of key parameters.


edited from
http://www.skf.com

A failed QJ bearing, behind is the Controller for Screw Air Compressors.














Sunday, August 23, 2009

Rental of Electrical Air Compressors

Rental of Electrical Air Compressors:


WE have a few new or almost new screw type oil flooded twin screw air compressors.

Main Motor Power : 
37 kw, ----- 2 units
75 kw. ----- 2 units
Maximum working pressure : 8 barg


Pre-Delivery Inspection *****






Many selection to choose from !!!!!




Dual Control for Rotary Screw Oil Flooded Air Compressors.

Increased Oil  [Coolant]  Consumption















1. 
 Blocked drainage [scavenging] line




2. 
Type of Oil [Coolant]
[ oil vapour content]







Rotary Compressor Coolant









One of the best for Rotary Screw & Vane Air Compressors


Mineral based, Long change intervals up to 8,000 hours.

Packing := 20 litres per pail


3. 
Over filled sump



4. 
Air Release
[Oil foam build-up]



Note: 
The oil separator tank  ( Vertical Design ) with separator element inside







Which Type of Screw Compressor are MOST efficient

Question ?

Which Type of Screws are most Efficient ?


*** Symmetry Profile vs Asymmetry Profile ! ***


Answer !



Asymmetry Rotors with both rotors of same rotor diameter



Asymmetry profile with same rotors diameter



Asymmetry Rotors with different rotors diameter ( Usually Male rotor have a bigger diameter than female one




A.
symmetry Profile ?

B.
Asymmetry Profile with same rotors diameter ?

C.
Asymmetry Profile with Big Male rotor and small female rotor ?

Which Air End have the best efficiency ?

What will be the answer ?

*****     A, B or C ?


Economic Service Life




Determinants: 


1. 
 Oil Care 

2. 
Selection of Oil / Coolant 

3.
 Operating Conditions 









Coolant ( Oil )



  1. 
 Oil Care 

Oil Change Interval! 
Oil Filter Change Interval! 

Air Filter Change Interval! 
Oil Compatibility Oil Contamination! 

  2. 
 Selection of Oil / [Coolant] 

Aging Resistance Insensitivity with Water Compressor Suitability Air Separation Efficiency 


Specially Blended for Malaysian, Hot and High Humidity Weather Conditions




  3. 
 Operating Conditions 

Ambient Temperature System Cooling Oil Temperature Foreign Harmful Bodies in Air