Gasoline dispenser with enhanced vapor recovery system

A system for dispensing volatile liquids, such as hydrocarbon fluids for a vehicle and for collecting vapors of the volatile liquids during dispensing to reduce atmospheric pollution comprising:

• a dispensing nozzle having a customer-operated dispensing valve for customer control of a flow of liquid through the nozzle and into a vehicle tank;
• the nozzle including a vapor inlet for collecting vapors during dispensing of volatile fluids and a vapor valve;
• means available to a customer for indicating demand for dispensing;
• a fueling line for delivering to the dispensing nozzle a flow of liquid from a tank storing a supply of volatile fluid and a fuel pump for pumping fluid to the nozzle through the fueling line;
• a vapor recovery line coupled through the vapor valve to the vapor inlet;
• a vacuum pump driven by a variable speed motor and coupled to the vapor recovery line for creating a vacuum in the vapor recovery line;
• means for causing the vacuum pump to create a prestart vacuum at the vacuum valve prior to commencement of a flow of liquid through the nozzle, the prestart vacuum enabling recovery through the vapor intake of an initial flow of vapor immediately after commencement of a flow of liquid through the nozzle;
• a control valve between the fuel pump and the flow meter for opening the fueling line to a flow of liquid from the tank to the nozzle after a partial vacuum is established;
• means responsive to an indication of a flow of liquid through the nozzle for causing the vacuum pump to operate at a rate having a predetermined relationship to the flow rate of the liquid in order to recover through the vapor intake an expected flow of vapor from the filling neck.

A system for dispensing fuel into tanks of automobiles having a capability for recovering fuel vapors displaced from a tank, the system comprising:

• a nozzle through which fuel is dispensed into a vehicle's tank, the nozzle having a manually controlled valve for controlling the flow of fuel through the nozzle;
• a pump for pumping fuel under pressure to the nozzle through a fuel line;
• a control valve in the fuel line for coupling a fuel under pressure in the pump to the nozzle;
• a meter coupled to the fuel line for measuring the flow rate of fuel in the fuel line going to the nozzle;
• a vapor intake disposed in close proximity to the nozzle for recovering vapors displaced from the fuel tank;
• a vapor recovery line coupled to the vapor intake through a vacuum valve;
• a vacuum pump coupled to the vapor recovery line for creating a vacuum in the line to draw in a flow of vapor from the tank;
• means for creating by running the vacuum pump prior to commencement of fuel flowing through the nozzle a prestart vacuum at the vacuum valve for assisting in capturing an initial flow of vapor immediately following commencement of a flow of fuel;
• means for opening the control valve after the prestart vacuum is established;
• and
• means for operating the vacuum pump upon indication of fuel flow from the meter at a rate having a predetermined relationship with the flow rate indicated by the meter.

A system for dispensing fuel into tanks of automobiles having a capability for recovering fuel vapors displaced from a tank, the system comprising:

• a nozzle through which fuel is dispensed into a vehicle's tank, the nozzle having a manually controlled valve for controlling the flow of fuel through the nozzle;
• a fuel pump for pumping fuel under pressure to the nozzle through a fuel line;
• a control valve in the fuel line for coupling a fuel under pressure in the pump to the nozzle;
• a meter coupled to the fuel line for measuring the flow rate of fuel in the fuel line going to the nozzle;
• a vapor intake disposed in close proximity to the nozzle for recovering vapors displaced from the fuel tank;
• a vapor recovery line coupled to the vapor intake through a vacuum valve;
• a vacuum pump coupled to the vapor recovery line for creating a vacuum in the line to draw in a flow of vapor from the tank;
• a processor coupled for controlling the fuel pump, control valve and vacuum pump, the processor specially programmed for
• operating the vacuum pump prior to commencement of fuel flowing through the nozzle to create a prestart vacuum at the vacuum valve for assisting in capturing an initial flow of vapor immediately following commencement of a flow of fuel,
• opening the control valve after the prestart vacuum is established, and
• operating the vacuum pump upon indication of fuel flow from the meter at a rate having a predetermined relationship with the flow rate indicated by the meter.