Process and system for the recovery of vapour

Abstract

A process and system for the recovery of vapour from a vessel holding a volatile liquid. The delivery of liquid to a vessel ( 6 ) is carried out such that at least one zone of negative pressure is created by the movement of the liquid whereby any vapour in the vessel is drawn into the liquid and returned to the vessel therein. The process and system is particularly suitable for recovering vapours from a tank as fuel is delivered to the tank

1 . A vapour recovery system for the recovery of vapour from a vessel holding a volatile liquid, the system comprising a delivery conduit ( 8 ) for delivering liquid to the vessel ( 6 ) and means for creating at least one zone of negative pressure by movement of said liquid whereby any vapour in the vessel is drawn into the liquid and returned to the vessel therein.  
     
     
         2 . A vapour recovery system as claimed in  claim 1  wherein diverting means is provided to impart movement in the liquid to create the zone of negative pressure.  
     
     
         3 . A vapour recovery system as claimed in  claim 2  wherein an angled member ( 26 ) is provided that extends obliquely to the normal flow of liquid.  
     
     
         4 . A vapour recovery system as claimed in  claim 2  or  3  wherein the diverting means is such as to impart a swirling motion in the liquid thereby setting up a coriolis effect to create a partial vacuum in the viscinity of the liquid.  
     
     
         5 . A vapour recovery system as claimed in  claim 2 ,  3  or  4  wherein the delivery conduit is provided with a chamber ( 10 ) having the diverting means.  
     
     
         6 . A vapour recovery system as claimed in  claim 5  wherein the chamber ( 10 ) is provided with an inwardly extending rim ( 24 ) around the periphery thereof that is angled to constrict the flow of liquid that passes therethrough.  
     
     
         7 . A vapour recovery system as claimed in  claim 5  or  claim 6  wherein the chamber has one or more members ( 26 ) that extend obliquely to at least a portion of the interior of the chamber.  
     
     
         8 . A vapour recovery system as claimed in  claim 5  or  claim 6  wherein the chamber is provided with a narrowing therein whereby the flow of liquid therethrough is restricted and then expands following its exit from the narrowing thereby creating the zone of negative pressure.  
     
     
         9 . A vapour recovery system as claimed in any one of  claims 5  to  8  wherein the chamber ( 10 ) is provided with a hollow bar or rod ( 14 ) therethrough that extends past the top of the chamber whereby the negative pressure created by the flow of fluid extends up the hollow bar or rod.  
     
     
         10 . A vapour recovery system as claimed in  claim 9  wherein the top of the bar ( 14 ) is connected to a supplementary pipe ( 16 ) that is in fluid communication with the vessel.  
     
     
         11 . A vapour recovery system as claimed in  claim 9  or  claim 10  wherein the base of the bar extends into a second delivery pipe ( 12 ) that delivers liquid to the vessel.  
     
     
         12 . A vapour recovery system as claimed in  claim 10  or  claim 11  wherein the supplementary pipe ( 16 ) is provided with a control valve ( 18 ) that allows vapour to enter the pipe only once a predetermined pressure is reached.  
     
     
         13 . A vapour recovery system as claimed in  claim 10 ,  11  or  12  wherein an expansion valve ( 20 ) is provided to have a cooling effect on the vapour and contents of the vessel.  
     
     
         14 . A vapour recovery system as claimed in any one of  claims 5  to  11  wherein a control valve ( 180 ) is provided within the chamber and is activated by the flow of liquid through the chamber.  
     
     
         15 . A vapour recovery system as claimed in  claim 14  wherein movement of the valve is assisted by the provision of a piston balance ( 302 ).  
     
     
         16 . The use of a vapour recovery system as claimed in any one of the preceding claims for the delivery of fuel from a fuel supply tanker to a storage tank.  
     
     
         17 . A vapour recovery system as claimed in  claim 2  wherein the diverting means is provided in a fluid dispensing nozzle ( 102 ).  
     
     
         18 . A vapour recovery system as claimed in  claim 17  wherein the fluid dispensing nozzle ( 102 ) is provided with an adapter ( 100 ) having means for diverting the flow of liquid.  
     
     
         19 . A vapour recovery system as claimed in  claim 18  wherein the adapter is in the form of a flow-diverting bush ( 108 ) that as movement of the liquid in such a manner as to create a zone of negative pressure.  
     
     
         20 . A vapour recovery system as claimed in  claim 19  wherein the flow-diverting bush is provided with at least one angled surface ( 116 , 119 ).  
     
     
         21 . A vapor recovery system as claimed in  claim 20  wherein the flow-diverting bush ( 108 ) is provided with an inner tube ( 110 ) at least partially surrounded by a sleeve ( 114 ).  
     
     
         22 . A vapour recovery system as claimed in  claim 21  wherein the sleeve is provided with means ( 116 ) to obstruct the flow of liquid trough the inner tube.  
     
     
         23 . A vapour recovery system as claimed in  claim 22  wherein the flow-diverting bush has a fist section, a second section and a third section, the first section being provided with grooves that form subsidiary channels ( 112 ) around the periphery of the inner tube ( 110 ), the sleeve ( 114 ) surrounding the middle of the section of the bush and having an angled flange ( 116 ) that obstructs the flow of fluid as it travels along the subsidiary channels, thereby deflecting the liquid.  
     
     
         24 . A vapour recovery system as claimed in  claim 21 ,  claim 22  or  claim 23  wherein the end of the inner tube ( 110 ) is provided with a chamfered edge ( 119 ) thereby constricting the flow of liquid that passes through the inner tube.  
     
     
         25 . A vapour recovery system as claimed in  claim 24  wherein the end of the inner tube is attached to a pipe ( 122 ) that is provided with a series of holes ( 118 ) that are substantially in line with the chamfered area ( 119 ) of the inner tube.  
     
     
         26 . A vapour recovery system as claimed in  claim 17  wherein the nozzle ( 500 ) itself is constructed to create a zone of negative pressure as fluid is passed through the nozzle.  
     
     
         27 . A vapour recovery system as claimed in  claim 26  where the nozzle is provided with diverting means and at least one aperture through a side of the nozzle for drawing vapour into the nozzle by means of the negative pressure created by the flow of liquid over the diverting means.  
     
     
         28 . A vapour recovery system as claimed in  claim 27  wherein the tube of the nozzle is provided with a narrowing in a region thereof that is surrounded by a sleeve, the wall of the narrowing and the sleeve having apertures whereby vapour can be drawn into the tube.  
     
     
         29 . A vapour recovery system as claimed in any one of  claims 17  to  28  wherein the nozzle is provided with a skirt ( 105 ) for forming a seal around the opening of the vessel ( 104 ).  
     
     
         30 . A liquid dispensing nozzle for the delivery of liquid to a vessel, the nozzle ( 500 ) comprising a conduit ( 501 ) having means ( 502 ,  503 ) for creating at least one zone of negative pressure due to the movement of liquid therethrough and at least one aperture ( 505 ) in the region that the negative pressure is created  
     
     
         31 . The use of a vapour recovery system as claimed in  claim 1  in a drop tube that delivers liquid to a storage tank.  
     
     
         32 . The use of a vapour recovery system as claimed in  claim 1  in a vehicle cap filler.  
     
     
         33 . A process for the recovery of vapour from a vessel holding a volatile liquid, the process comprising the steps of delivering the liquid to a vessel and creating at least one zone of negative pressure due to movement of said liquid whereby any vapour in the vessel is drawn into the liquid and returned to the vessel therein.