Gasoline vapor recovery system and method utilizing vapor detection
AssigneeDresser Industries, Inc.
InventorBo-Goran Andersson
Life of this patent
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Abstract
A gasoline vapor recovery system and method in which a flow metering unit is provided for measuring the flow of a mixture of air and gasoline vapor from a vehicle tank and for determining the density of the gasoline vapor in the mixture. A value is provided for varying the flow of the mixture from the tank, and a control unit is operatively connected to the flow metering unit and to the valve for adjusting the position of the valve, and therefore the flow of the mixture from the tank, in response to the density of the gasoline vapor in the mixture and the gasoline flow.
Claims53
A system for recovering a mixture of gasoline vapor and air flowing from a vehicle tank during dispensing of gasoline into the tank, the system comprising a flow metering unit adapted to be connected to the tank for receiving the mixture as it flows from the tank and for producing an output signal proportional to the volumetric flow of the mixture and the pressure drop over the flow metering unit, a flow varying unit for varying the flow of the mixture from the tank, and a control unit connected to the flow metering unit and to the flow varying unit for receiving the output signal, determining the density of the gasoline vapor in the mixture based on the output signal, and controlling the operation of the flow varying unit, and therefore the flow of the mixture from the tank, in response to the density of the gasoline vapor in the mixture.
A method for recovering a mixture of air and gasoline vapor flowing from a vehicle tank during dispensing of gasoline into the tank, the method comprising the steps of measuring the flow of the mixture from the tank to produce an output signal having a frequency proportional to the volumetric flow of the mixture and an amplitude proportional to the pressure drop of the mixture, calculating the density of the mixture based on the volumetric flow and pressure drop, determining the density of the vapor in the mixture based on the density of the mixture, and varying the flow of the mixture from the tank in response to the amount of gasoline vapor in the mixture.
A system for recovering a mixture of air and gasoline vapor flowing from a vehicle tank during dispensing of gasoline into the tank, the system comprising a flow metering unit for selectively receiving samples of the mixture and samples of air and for determining flow conditions of the mixture and the air and producing an output signal proportional to the volumetric flow of the mixture and the air and the pressure drop of the mixture and the air over the flow metering unit, a flow varying unit for varying the flow of the mixture from the tank, and a control unit connected to the flow metering unit and to the flow varying unit for calculating the density of the mixture and the air based on their respective volumetric flows, determining the density of the gasoline vapor in the mixture based on the density of the mixture and the density of the air, and adjusting the position of the flow varying unit, and therefore the flow of the mixture from the tank, accordingly.
A system for dispensing gasoline from a plurality of storage tanks into an vehicle tank and recovering a mixture of air and gasoline vapor from the vehicle tank, the system comprising a plurality of gas dispensing nozzles for respectively dispensing the gasoline from one of the storage tanks into the vehicle tank, a flow metering device, a plurality of conduits respectively extending from the nozzles to the flow metering device for passing the mixture to the flow metering device, the flow metering device determining flow conditions of the mixture as it flows from the vehicle tank and for generating an output signal corresponding to the flow conditions, a flow varying unit for selectively passing the gasoline vapor from the nozzles and conduits to the flow metering device and for varying the flow of the mixture from the tank, and a control unit connected to the flow metering device and to the flow varying unit for adjusting the position of the flow varying unit, and therefore the flow of the mixture from the vehicle tank, in response to the density of the gasoline vapor;
- wherein the flow varying unit comprises a first unit having a number of inlets respectively connected to the sources and at least one opening, a second unit having an inlet and an outlet which are normally out of communication to prevent flow therethrough, and drive means for moving one of the first or second units relative to the other unit so that one of the inlets of the first unit registers with the inlet of the second unit and so that the opening of the first unit communicates with the inlet of the second unit and with the outlet of the second unit to permit the flow of the mixture from the one inlet of the first unit, through the inlet of the second unit, and to the outlet of the second unit for discharge therefrom.
A system for recovering a mixture of gasoline vapor and air flowing from a vehicle tank during dispensing of gasoline into the tank, the system comprising a flow metering unit connected to the tank for receiving the mixture as it flows from the tank and for generating a first output signal corresponding to the flow conditions of the mixture, the flow metering unit also selectively receiving ambient air and generating a second output signal corresponding to the flow conditions of the air, a flow varying unit for varying the flow of the mixture from the tank, and a control unit connected to the flow varying unit and to the flow metering unit for processing the first and second output signals, determining the density of the gasoline vapor in the mixture based on the output signals, and adjusting the position of the flow varying unit, and therefore the flow of the mixture from the tank, in response to the density of the gasoline vapor.
A system for recovering a mixture of gasoline vapor and air flowing from a vehicle tank during dispensing of gasoline from a plurality of sources through one of a plurality of nozzles into the tank, the system comprising a flow metering unit, a plurality of conduits respectively extending from the nozzles, a valve for selectively passing the mixture from the conduits to the flow metering unit and for varying the flow of the mixture from the tank to the flow metering unit, the flow metering unit generating an output signal proportional to the volumetric flow of the mixture and the pressure drop over the flow metering unit, and a control unit connected to the valve and to the flow metering unit for receiving the output signal, the control unit including means for calculating the density of the mixture based on the output signal, for determining the density of the gasoline vapor in the mixture based on the density of the mixture, and for adjusting the position of the valve, and therefore the flow of the mixture from the tank, in response to the density of the gasoline vapor in the mixture, the valve comprising a first unit having a number of inlets respectively connected to the conduits and at least one opening, a second unit having an inlet and an outlet which are normally out of communication to prevent flow therethrough, and a drive member for moving one of the units relative to the other unit so that one of the inlets of the first unit registers with the inlet of the second unit and so that the opening of the first unit communicates the inlet of the second unit with the outlet of the second unit to permit flow of the mixture from the inlet of the first unit, through the inlet of the second unit, and to the outlet of the second unit for discharge therefrom.
A method for recovering a mixture of air and gasoline vapor from a vehicle tank during dispensing of gasoline into the tank, the method comprising the steps of measuring the flow of the mixture from the tank to produce output signals having frequencies proportional to the volumetric flows of the mixture, and amplitudes proportional to the pressure drops of the mixture;
- determining the density of the mixture based on the volumetric flows and pressure drops;
- measuring the flow of air;
- determining the density of the air based on the flow of the air;
- determining the density of the gasoline vapor based on the densities of the mixture and the air by subtracting the density of the air from the density of the mixture;
- and varying the flow of the mixture from the tank in response to variations in the density of the gasoline vapor in the mixture.
A method for recovering a mixture of gasoline vapor and air flowing from a vehicle tank during dispensing of gasoline into the tank, the method comprising the steps of receiving the mixture as it flows from the tank, generating a first output signal corresponding to the flow conditions of the mixture, selectively receiving ambient air, generating a second output signal corresponding to the flow conditions of the air, receiving the first and second output signals and determining the density of the gasoline vapor in the mixture based on the output signals, and adjusting the flow of the mixture from the tank, in response to the density of the gasoline vapor.
Dependencies are inferred from the claim text.