PRINCIPLES OF NAVAL ENGINEERING 



The use of strainers and filters does not 

 solve the problem of water contamination of lu- 

 bricating oil. Even a very small amount of water 

 in lubricating oil can be extremely damaging to 

 machinery, piping, valves, and other equipment. 

 Water in lubricating oil can cause widespread 

 pitting and corrosion; also, by increasing the 

 frictional resistance, water can cause the oil 

 film to break down prematurely. Every effort 

 must be made to prevent the entry of water into 

 any lubricating system. 



REMOVING CONTAMINATION 



In spite of all efforts, a certain amount of 

 contamination of lubricating oil is to be expected. 

 Aboard ship, centrifugal purifiers are used to 



remove impurities from lubricating oil and set- 

 tling tanks are provided to permit used oil to 

 stand while water and other impurities settle out. 



Centrifugal Purifiers 



A centrifugal purifier is essentially a bowl 

 or hollow cylindrical container which is rotated 

 at high speed while contaminated oil is forced 

 through and rotated with the container. The cen- 

 trifugal force imposed on the oil by the high 

 rotational speed of the container causes the sus- 

 pended foreign matter to separate from the oil. 



Materials that are soluble in each other can- 

 not be separated by centrifugal force. For ex- 

 ample, salt cannot be removed from sea water 

 by centrifugal force because the salt and water 



COVER CLAMP HOOK 



LARGE SPRING 



COVER CLAMP SPRING 

 LONG COVER CLAMP 



INLET ARM SEAL RING 

 SPRING GUIDE 



BALL CHECK SPRING 



BALL CHECK VALVE 

 VALVE STOP SCREW ^ 



INLET ARM 

 REGULATING TUBE 

 COVER TOP 

 COVER TOP SCREW 

 COVER CLAMP NUT 

 FRAME COVER 



HOPPER 



SEAL RING 



SHORT COVER CLAMP 

 SEAL RING 

 BRAKE 

 BOWL 



STUD 



TOP BEARING 



FRAME 



BOWL SPINDLE 



BOTTOM SCREW 



75.231 



Figure 6-2.— Disk-type centrifugal purifier. 

 116 



