Patent ID: 6131621
Filing Date: 2000-10-17
Classification: B67D

Abstract:
A fuel dispensing system comprising:a fuel delivery line connected at one end to a fuel reservoir and at the other end to a fuel delivery nozzle;means for delivering fuel from the fuel reservoir to the fuel dispensing nozzle along said fuel delivery line with a variable volumetric flow;first sensor means for determining the said volumetric fuel flow rate;a vapour recovery line connected to a vapour inlet connected to the fuel dispensing nozzle;vapour recovery means located in the vapour recovery line;second sensor means for determining the volumetric vapour flow rate in the vapour recovery line; andcontrol means responsive to outputs of the first and second sensors for controlling the vapour recovery means to ensure that the volumetric vapour flow rate in the vapour recovery line is a predetermined function of the volumetric fuel flow rate,wherein:a) the second sensor means comprises a Fleisch tube in combination with a differential pressure transducer; andb) the vapour recovery means comprises a vapour recovery pump and a variable control valve or damper situated in the vapour recovery line; andc) after each fuel dispensing operation the vapour recovery pump continues to run and the variable control valve is pulsed open and closed for a predetermined period of time to clear the Fleisch tube of any liquid fuel.