Liquid feed pump apparatus

Abstract

An adjustment channel is connected to first and second pump mechanisms in parallel therewith. The flow of a liquid sent by pump heads is split, and part of the liquid is sent to an outlet port side, while the remaining liquid flows through the adjustment channel and is returned to an inlet port side. The adjustment channel has a restrictor which is so arranged that the flow rate is set to 100 μL/min to 1 mL/min, and pressure of 2 MPa to 20 MPa or thereabouts is applied thereto. In micro LC and nano LC, the flow rate of a column is 100 nL/min to 10 μL/min or thereabouts, and pressure of several MPa to 20 MPa or thereabouts is applied. Therefore, of the liquid sent from the pump mechanism, 0.1% to 1% is delivered from the outlet port, while the remaining liquid flows through the adjustment channel and is returned to the inlet port side.

1 . A liquid feed pump apparatus comprising: 
 a pump head for sucking a liquid from an inlet port and feeding the liquid from an outlet port;    a flow meter provided on an outlet port side of the pump head to measure a flow rate of the liquid fed to an outside from the outlet port;    an adjustment channel provided in parallel with the pump head to return to an inlet port side of the pump head part of the liquid which is sent to the outlet port of the pump head; and    a controller to which an output of the flow meter is inputted and which controls the driving of the pump head so that a value of the output of the flow meter becomes a predetermined value.    
   
   
       2 . The liquid feed pump according to  claim 1 , further comprising: 
 an opening valve provided in the adjustment channel.    
   
   
       3 . The liquid feed pump according to  claim 1 , further comprising: 
 a restrictor provided in the adjustment channel, in which the flow rate is set to 100 μL/min to 1 mL/min, and pressure of 2 MPa to 20 MPa or thereabouts is applied thereto.