Fluid particle monitor and methods related thereto

Abstract

A fluid analysis system and method for in situ optically imaging a fluid, such as lubricating oil, sampled from a flow path. The system has a chamber with an inlet in fluid communication with fluid flowing under pressure in the flow path. The pressure of the received fluid in the chamber is reduced, the reduced pressure fluid is directed from the the chamber into the fluid analysis system, and the fluid analysis system optically images the fluid. The fluid analysis system can produce data representative of particle size, particle shape, or number of particles. In one embodiment, a valve for directing fluid to the chamber and a valve for returning fluid from the chamber to the flow path under pressure allow the fluid to flow through the chamber for a period before shutting the valves, reducing the pressure of the fluid, and optically imaging the fluid.

1 . A method for sampling and monitoring of a fluid flowing in a fluid path, the method comprising: 
 opening a first valve connecting the fluid path to a chamber to direct the fluid from the fluid path into the flow chamber,    opening a second valve disposed downstream of the first valve, the second valve arranged to allow the fluid to exit from the chamber into the flow path at a location downstream of the first valve,    allowing the fluid to circulate through the chamber for a period,    trapping a portion of the fluid in the chamber by closing a first valve and a second valve,    reducing the pressure of the fluid in the chamber,    directing the fluid in the chamber to flow through a fluid monitoring device, and    analyzing the fluid flowing through the fluid monitoring device to produce data representative of at least one fluid characteristic.    
     
     
         2 . The method according to  claim 1 , wherein the period is sufficient to provide a representative sample of the fluid in the flow path.  
     
     
         3 . The method according to  claim 1 , wherein the period is at least 3 minutes.  
     
     
         4 . The method according to  claim 1 , wherein the period is at least 15 minutes.  
     
     
         5 . The method according to  claim 1 , further comprising: 
 releasing the fluid from the monitoring device.    
     
     
         6 . The method according to  claim 1 , wherein the reducing the pressure of the fluid in the chamber comprises allowing at least a portion of the fluid in the chamber to flow into an expansion chamber.  
     
     
         7 . A method according to  claim 1 , wherein the reducing the pressure of the fluid in the chamber comprises opening a valve in fluid communication with the chamber and an expansion chamber.  
     
     
         8 . A method according to  claim 1 , wherein the fluid monitoring device is an optical device comprising a light source and an optical detector.  
     
     
         9 . A method according to  claim 1 , comprising pumping at least a portion of the fluid in the chamber to the fluid monitoring device.  
     
     
         10 . A method according to  claim 9 , wherein the fluid monitoring device comprises a pump for pumping the fluid to the fluid monitoring device.  
     
     
         11 . A method according to  claim 1 , wherein the at least one fluid characteristic is particle size, particle shape, or number of particles.  
     
     
         12 . An apparatus for in situ sampling and monitoring a fluid flowing in a flow path comprising: 
 an inlet and an outlet connected to a chamber, the chamber being adapted for receiving fluid from the flow path through the inlet and returning the fluid to the flow path through the outlet,    a first valve for connecting the inlet to the flow path,    a second valve for connecting the outlet to the flow path,    an access valve provided for leading fluid from the chamber into a fluid monitoring system,    a pressure reducer connected to the chamber and adapted to reduce pressure of the fluid in the chamber to a pressure suitable for the fluid monitoring system.    
     
     
         13 . An apparatus according to  claim 12 , further comprising: 
 the fluid monitoring system.    
     
     
         14 . An apparatus according to  claim 13 , wherein the fluid monitoring system is an optical system comprising a light source and an optical detector.  
     
     
         15 . An apparatus according to  claim 14 , wherein the fluid monitoring system optically images particles in the fluid to produce data characteristic of at least one of particle size, particle shape, and number of particles.  
     
     
         16 . An apparatus according to  claim 15 , further comprising: 
 a computer in communication with the fluid monitoring system adapted to store the data or transfer the data from the monitor system.    
     
     
         17 . An apparatus according to  claim 12 , further comprising: 
 an expansion chamber in fluid communication with the third valve for reducing pressure of the fluid in the chamber.    
     
     
         18 . A fluid analysis system for monitoring particles in a fluid, the system comprising: 
 a chamber in fluid communication with fluid flowing under pressure in a flow path, the chamber having an inlet for receiving at least a portion of the fluid from the flow path,    means for reducing a pressure of the received fluid in the chamber to a reduced pressure,    an optical imaging device comprising an optical source and an optical detector arranged to image particles present in fluid flowing through the optical imaging device,    and means for directing fluid from the chamber at the reduced pressure to the optical imaging device for imaging.    
     
     
         19 . A fluid analysis system according to  claim 18 , wherein the system is an engine fluid analysis system.  
     
     
         20 . A fluid analysis system according to  claim 18 , wherein the fluid is a lubricating oil.  
     
     
         21 . A fluid analysis system according to  claim 18 , wherein the fluid is hydraulic fluid.  
     
     
         22 . A fluid analysis system according to  claim 18 , wherein the means for reducing a pressure of the received fluid in the chamber to a reduced pressure includes an expansion chamber in fluid communication with the chamber.  
     
     
         23 . A fluid analysis system according to  claim 22 , comprising a third valve arranged to allow fluid in the chamber to flow into the expansion chamber.  
     
     
         24 . A fluid analysis system according to  claim 18 , wherein the means for directing fluid from the chamber includes a pipe or line connected between the chamber and the optical imaging device.  
     
     
         25 . A fluid analysis system according to  claim 18 , wherein the means for directing fluid from the chamber includes a pump for pumping fluid through the optical imaging device.  
     
     
         26 . A method for sampling and optically imaging a fluid flowing in a flow path, the method comprising: 
 directing at least a portion of the fluid flowing in the flow path into a storage chamber,    reducing the pressure of the fluid in the storage chamber,    directing at least a portion of the fluid from the storage chamber into a fluid analyzer, and    the fluid analyzer optically imaging the fluid directed from the storage chamber.    
     
     
         27 . A method according to  claim 26 , further comprising: 
 returning the imaged fluid from the fluid analyzer to the flow path.    
     
     
         28 . A method according to  claim 27 , further comprising: 
 returning fluid from the storage chamber into the flow path before directing at least a portion of the fluid from the storage chamber into the fluid analyzer.