In situ sampling and monitoring a fluid

Abstract

A method for in situ sampling and monitoring of a fluid flowing in a flow path, whereby the fluid is to be directed to a chamber a first valve may provide a connection between an inlet to the chamber and the flow path and a second valve may provide a connection between flow path, comprising the following steps: a) opening the first valve and the second valve to let the incoming fluid flow through the inlet to the chamber outlet into the continuation of the fluid path, thereby allowing fluid to circulate through the chamber for a certain time, b) trapping the fluid in the chamber by closing the second valve and thereafter closing the first valve, c) opening a valve 9 pressure in the chamber suitable for monitoring the fluid, d) opening an access valve 11 and leading the fluid trapped in the chamber into a monitor system wherein the fluid is analyzed, and thereby providing the data representing the fluid characteristics, e) providing exit for the fluid analyzed through a further fluid path possibly to a low pressure section of the system.

1 . A method for in situ sampling and monitoring of a fluid flowing in a flow path ( 3 ), whereby the fluid is to be directed to a chamber; 
 a first valve ( 7 ) provides a connection between an inlet ( 4 ) to the chamber ( 6 ) and the flow path,    a second valve ( 8 ) provides a connection between an outlet ( 4 ) from the chamber and the flow path,    wherein the method comprises the following steps:    a) opening the first valve ( 7 ) and the second valve ( 8 ) to let the fluid flow through the inlet ( 4 ) to the chamber ( 6 ) and from the chamber through the outlet ( 4 ) into the continuation of the fluid path ( 14 ), thereby allowing fluid to circulate through the chamber ( 6 ) for a certain time,    characterized by    b) trapping the fluid in the chamber ( 6 ) by closing the second valve ( 8 ) and thereafter closing the first valve ( 7 ),    c) opening a valve ( 9 ) or an access valve ( 11 ) for reducing pressure, to obtain a pressure in the chamber ( 6 ) suitable for monitoring the fluid,    d) and leading the fluid trapped in the chamber ( 6 ) into a monitor system ( 2 ) through the access valve ( 11 ) wherein the fluid is analyzed, and thereby providing data representing the fluid characteristics,    e) providing exit for the fluid analyzed through a further fluid path ( 13 ) possibly to a low pressure section of the system.    
   
   
       2 . A method according to  claim 1 ,  
     characterized by that in step c) opening the valve ( 9 ) for the chamber to communicate with an expansion chamber ( 10 ).  
   
   
       3 . A method according to  claim 2 ,  
     characterized by opening a valve ( 12 ) for maintaining pressure in the chamber ( 6 ).  
   
   
       4 . A method according to  claim 1 ,  
     characterized by performing step a) and loading a gas cavity ( 16 ), preferably via an internal check valve ( 17 ), allowing the pressure to build up in the gas cavity ( 16 ).  
   
   
       5 . A method according to  claim 4 ,  
     characterized by utilising the gas contained in the gas cavity ( 16 ) to pressurize the fluid to force the fluid through the chamber ( 6 ) and through the monitor system ( 2 ).  
   
   
       6 . A method according to one of the claims  1 - 3 ,  
     characterized by leading the fluid into the monitor system by the effect of an internal pump of the monitor system.  
   
   
       7 . A method according to one of the proceeding claims,  
     characterized by analyzing the fluid and the possible particles therein by a monitor system ( 2 ) such as an optical system comprising a light source, an optical detector and means for processing data.  
   
   
       8 . A method according to one of the proceeding claims,  
     characterized by storing the data from the analyzed fluid, and/or transferring the data to a remote computer for evaluation or maintenance support, wherein the data can be transferred automatically after each analysis record, after an accumulation of a number of analyses record, or on a time sequence or on demand by a local or remote operator.  
   
   
       9 . An apparatus for in situ sampling and monitoring a fluid flowing in a flow path comprising: 
 an inlet ( 4 ) and an outlet ( 4 ) connected to a chamber ( 6 ),    a first valve ( 7 ) provided for connecting the inlet ( 4 ) to the flow path ( 3 ),    a second valve ( 8 ) provided for connecting the outlet ( 4 ) to the flow path ( 3 ),    thereby allowing the fluid to fill the chamber ( 6 ), circulate the fluid through the chamber ( 6 ) for a certain time, and capturing the fluid in the chamber ( 6 ),    characterized by    providing an access valve ( 11 ) for leading the fluid which is captured in the chamber ( 6 ) into a monitor system ( 2 ) where the fluid is to be analyzed, wherein    reduction of the pressure to in the chamber ( 6 ) suitable for the monitor system ( 2 ) is taken care of by the access valve ( 11 ) or a valve ( 9 ).    
   
   
       10 . An apparatus according to  claim 9 ,  
     characterized by 
 the provision of a valve ( 12 ) for relieving pressure.  
 
   
   
       11 . An apparatus according to  claim 9  or  10 ,  
     characterized by the provision of an expansion chamber ( 10 ) communicating with the chamber ( 6 ) through the valve ( 9 ) for reducing pressure.  
   
   
       12 . An apparatus according to  claim 9 ,  
     characterized by 
 the provision of a gas cavity ( 16 ), which prefereably contains a separation membrane between the liquid fluid and gas.  
 
   
   
       13 . An apparatus according to  claim 12 ,  
     characterized in that 
 the gas cavity ( 16 ) is provided with a check valve ( 17 ), which preferably is operated by a solenoid ( 19 ).  
 
   
   
       14 . An apparatus according to one of the claims  9 - 13 ,  
     characterized in that the monitor system ( 2 ) is an optical system comprising a light source, an optical detector, means for processing data.  
   
   
       15 . An apparatus according to one of the claims  9 - 14 ,  
     characterized in that the monitor system is connected to a computer, for transferring the data of the analyzed fluid, possibly to a remote site for evaluation or maintenance support, wherein the data can be transferred automatically after each analysis record, after an accumulation of a number of analyses record, or on a time sequence or on demand by a local or remote operator.