Increased sensitivity for turbine flow meter

A fuel dispenser for dispensing fuel to a vehicle, comprising:

• a nozzle;
• a hose connected to said nozzle;
• a control system;
• a fuel delivery line having an inlet port that receives fuel, and an outlet port that couples to said hose;
• a valve located inline said fuel delivery line and under control of said control system, wherein said control system opens said valve to allow fuel to flow through said fuel delivery line to be delivered through said hose and said nozzle to the vehicle;
• and
• a turbine meter located inline said fuel delivery line, comprising:
• an outer housing comprised of a low permeable material forming an inlet port on one end of said outer housing and an outlet port on the other end of said outer housing;
• a shaft supported inside said outer housing along an axis parallel to said outer housing;
• a turbine rotor mounted on said shaft, wherein said turbine rotor rotates when the material flows through said inlet port;
• an orifice contained in said outer housing that forms a first pickup port wherein a first end of said orifice extends outward to the outer surface of said outer housing, and said second end of said orifice extends down to a higher permeable inner housing proximate to said turbine rotor;
• and
• a first pickup coil that is mounted within said first pickup port and excited by a signal received through said inner housing from said turbine rotor as said turbine rotor rotates;
• said turbine meter measures the amount of fuel traveling through said fuel delivery line and sends a signal indicated of the amount of fuel to said control system.

A vapor recovery system, comprising:

• an underground storage tank that contains fuel and vapor;
• a vent coupled to said underground storage tank;
• a membrane coupled inline to said vent that receives said vapor from said underground storage tank and substantially separates said vapor into a hydrocarbon mixture and an air mixture;
• a pressure valve coupled inline to said vent downstream of said membrane wherein said pressure valve is opened to release said air mixture to atmosphere when said underground storage tank is under a threshold pressure and said hydrocarbon mixture is returned back to said underground storage tank;
• and
• a turbine flow meter that measures the amount of air being released to atmosphere, comprising:
• an outer housing comprised of a low permeable material forming an inlet port on one end of said outer housing and an outlet port on the other end of said outer housing;
• a shaft supported inside said outer housing along an axis parallel to said outer housing;
• a turbine rotor mounted on said shaft, wherein said turbine rotor rotates when said material flows through said inlet port;
• an orifice contained in said outer housing that forms a first pickup port wherein a first end of said orifice extends outward to the outer surface of said outer housing, and said second end of said orifice extends down to a higher permeable inner housing proximate to said turbine rotor;
• and
• a first pickup coil that is mounted within said first pickup port and excited by a signal received through said inner housing from said turbine rotor as said turbine rotor rotates;
• said turbine meter measures the amount of air mixture traveling through said vent.

A vapor recovery system that captures vapors expelled from a vehicle during refueling and returns the vapors to an underground storage tank, comprising:

• a fuel dispenser comprising a control system and a vapor recovery system that captures vapors expelled from the vehicle during refueling and returns the vapors through a vapor return line to the underground storage tank;
• a turbine flow meter coupled inline to said vapor return line that measures the amount of vapors being returned to the underground storage tank wherein said control system adjusts said vapor recovery system to vary the rate of recovery of the vapors based on the measurement of the amount of vapors being returned to the underground storage tank, said turbine flow meter comprising:
• an outer housing comprised of a low permeable material forming an inlet port on one end of said outer housing and an outlet port on the other end of said outer housing;
• a shaft supported inside said outer housing along an axis parallel to said outer housing;
• a turbine rotor mounted on said shaft, wherein said turbine rotor rotates when the material flows through said inlet port;
• an orifice contained in said outer housing that forms a first pickup port wherein a first end of said orifice extends outward to the outer surface of said outer housing, and a second end of said orifice extends down to a higher permeable inner housing proximate to said turbine rotor;
• and
• a first pickup coil that is mounted within said first pickup port and excited by a signal received through said inner housing from said turbine rotor as said turbine rotor rotates;
• said first pickup coil generates a signal indicative of the amount of vapors passing through said turbine meter.

A method of measuring the flow rate of a material, comprising the steps of:

• passing a material through an inlet port of an inner housing comprised of a high permeable material;
• rotating a turbine rotor mounted inside said inner housing as said materials passes through said inner housing;
• receiving a signal from a first pickup coil mounted on said inner housing proximate to said turbine rotor and within a first pickup port in an outer housing of a low permeable material formed around said inner housing to detect rotation of said turbine rotor;
• and
• correlating the rotation of said turbine rotor into a flow rate of said material.

A method of manufacturing a turbine flow meter, comprising the steps of:

• forming an outer housing constructed of a low permeable material;
• placing a turbine rotor on a shaft;
• placing said shaft inside said outer housing on an axis in parallel with said outer housing;
• placing an orifice in said outer housing that forms a first pickup port wherein a first end of said orifice extends outward to the outer surface of said outer housing, and said second end of said orifice extends down to a higher permeable inner housing placed proximate to said turbine rotor;
• and
• placing said first pickup port in said outer housing proximate to the location of said turbine rotor that runs down to the outer surface of said inner housing.