# US 8,770,237 B2 · Vapor recovery pump regulation of pressure to maintain air to liquid ratio > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,237 B2 - Document ID: US8770237B2 - Status: Granted - Kind: B2 - Application number: 12/906,879 - Filed: 2010-10-18 - Published: 2011-07-07 - Granted: 2014-07-08 - Earliest claimed: 2009-10-19 - Assignees: Veeder-Root Company - Applicants: David Bolt; Dale Spence; Dale Ewing; David Jonathan Hassell; John Layne; Lindsay Bruce Dalziel - Inventors: David Bolt; Dale Spence; Dale Ewing; David Jonathan Hassell; John Layne; Lindsay Bruce Dalziel - Web page: https://patentgrep.com/patent/US8770237B2 ## CPC - B67D 7/54: with means for preventing escape of liquid or vapour or for recovering escaped liquid or vapour (B67D7/44 takes precedence) - B67D 7/0482: {using pumps driven at different flow rates} - B67D 7/0486: {Pumps driven in response to electric signals indicative of pressure, temperature or liquid flow} - B67D 2007/746: {by mixing different fuel grades or fuel and oil} - B67D: DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR (cleaning pipes or tubes or systems of pipes or tubes B08B9/02; emptying or filling of bottles, jars, cans, casks, barrels, or similar containers, not otherwise provided for B67C; water supply E03; pipe systems F17D; domestic hot-water supply systems F24D; measuring volume, volume flow, mass flow or liquid level, metering by volume G01F; coin-freed or like apparatus G07F) ## Abstract A method of operating a vapor recovery system that recovers vapors expelled from a vehicle during refueling at a fuel dispensing point and returns the vapors to an underground storage tank through a vapor flow path that is in fluid communication with an air to liquid regulator valve and a vapor pump. The method includes dispensing fuel into the vehicle through the fuel dispensing point, regulating an amount of vapor that is recovered through the fuel dispensing point with the air to liquid regulator valve in proportion to the fuel dispensed into the vehicle, detecting a parameter of the vapor recovery system, and maintaining a substantially constant pressure level in a first portion of the vapor return path that is disposed between the vapor pump and the air to liquid regulator valve. ## Claims ### Claim 1 A system for controlling a vapor recovery system that recovers vapors expelled from a vehicle during refueling at a fuel dispensing point and returns the vapors to an underground storage tank in a service station environment, comprising: an air to liquid regulator valve associated with the fuel dispensing point, the air to liquid regulator valve being configured to regulate an amount of vapor that is recovered through the fuel dispensing point for a given amount of fuel that is dispensed through the fuel dispensing point; a vapor pump that is in fluid communication with the air to liquid regulator valve, the vapor pump having an inlet side and an outlet side; a vapor flow path that is in fluid communication with the air to liquid regulator valve and the vapor pump; and a controller operatively connected to the vapor recovery system adapted to: monitor a parameter of the vapor recovery system; and maintain a substantially constant pressure level in a first portion of the vapor flow path that is disposed between the inlet side of the vapor pump and the air to liquid regulator valve. ### Claim 2 (depends on 1) The system of claim 1, wherein the parameter of the vapor recovery system that is monitored by the controller is a pressure value within the first portion of the vapor flow path. ### Claim 3 (depends on 2) The system of claim 2, wherein the vapor recovery system further comprises a pressure sensor operatively connected to the first portion of the vapor flow path. ### Claim 4 (depends on 2) The system of claim 2, wherein the vapor recovery system further comprises a variable speed motor that drives the vapor pump. ### Claim 5 (depends on 4) The system of claim 4, wherein the controller is further adapted to adjust an amount of current that is provided to the variable speed motor of the vapor pump in response to the pressure value at the first portion of the vapor flow path. ### Claim 6 (depends on 4) The system of claim 4, wherein the controller is further adapted to control the amount of torque that is provided to the vapor pump by the variable speed motor in response to the pressure valve at the first portion of the vapor flow path. ### Claim 7 (depends on 1) The system of claim 1, wherein the vapor recovery system further comprises a variable speed motor that drives the vapor pump, and the parameter of the vapor recovery system that is monitored by the controller is an amount of current that is being drawn by the variable speed motor. ### Claim 8 (depends on 7) The system of claim 7, wherein the controller is further adapted to adjust an amount of current that is provided to the variable speed motor of the vapor pump in response to the amount of current that is being drawn by the variable speed motor. ### Claim 9 (depends on 1) The system of claim 1, wherein the vapor recovery system further comprises a variable speed motor that drives the vapor pump and the parameter of the vapor recovery system that is being monitored by the controller is a speed of rotation of the vapor pump. ### Claim 10 (depends on 9) The system of claim 9, wherein the controller is further adapted to adjust an amount of current that is provided by the variable speed motor of the vapor pump in response to the speed of rotation of the vapor pump. ### Claim 11 (depends on 1) The system of claim 1, wherein the vapor pump is a fixed speed pump. ### Claim 12 (depends on 11) The system of claim 11, wherein the fixed speed pump further comprises one of a swash pump, a rotary vane pump and a piston pump. ### Claim 13 (depends on 12) The system of claim 12, further comprising an electronic proportional valve that is disposed in the first portion of the vapor flow path between the vapor pump and the air to liquid regulator valve. ### Claim 14 (depends on 1) The system of claim 1, further comprising a plurality of fuel dispensing points that are in fluid communication with the first portion of the vapor flow path, each fuel dispensing point including a corresponding air to liquid regulator valve. ### Claim 15 A method of operating a vapor recovery system that recovers vapors expelled from a vehicle during refueling at a fuel dispensing point and returns the vapors to an underground storage tank through a vapor flow path that is in fluid communication with an air to liquid regulator valve and a vapor pump, comprising: dispensing fuel into the vehicle through the fuel dispensing point; regulating an amount of vapor that is recovered through the fuel dispensing point with the air to liquid regulator valve in proportion to the fuel dispensed into the vehicle; detecting a parameter of the vapor recovery system; and maintaining a substantially constant pressure level in a first portion of the vapor return path that is disposed between the vapor pump and the air to liquid regulator valve. ### Claim 16 (depends on 15) The method of claim 15, further comprising controlling the operation of the vapor pump in response to the detected parameter of the vapor recovery system. ### Claim 17 (depends on 15) The method of claim 15, wherein the detected parameter of the vapor recovery system is a pressure value of the first portion of the vapor return path. ### Claim 18 (depends on 15) The method of claim 15, wherein the detected parameter of the vapor recovery system is an amount of current that is drawn by the vapor pump. ### Claim 19 (depends on 15) The method of claim 15, wherein the detected parameter is a rate of rotation of the vapor pump. ### Claim 20 (depends on 15) The method of claim 15, wherein the step of maintaining a substantially constant pressure further comprises varying a rate of rotation of the vapor pump by adjusting an amount of current that is provided to the vapor pump. ### Claim 21 (depends on 15) The method of claim 15, wherein the step of maintaining a substantially constant pressure is performed by a fixed speed pump. ### Claim 22 A system for controlling a vapor recovery system that recovers vapors expelled from a vehicle during refueling at a fuel dispensing point and returns the vapors to an underground storage tank in a service station environment, comprising: an air to liquid regulator valve associated with the fuel dispensing point, the air to liquid regulator valve being configured to regulate an amount of vapor that is recovered through the fuel dispensing point for a given amount of fuel that is dispensed through the fuel dispensing point; a vapor pump that is in fluid communication with the air to liquid regulator valve, the vapor pump having an inlet side and an outlet side; a vapor flow path that is in fluid communication with the air to liquid regulator valve and the vapor pump; and a mechanical regulator valve that is in fluid communication with both the inlet side and the outlet side of the vapor pump, wherein the mechanical regulator valve is adapted to maintain a substantially constant pressure level in a first portion of the vapor flow path that is disposed between the inlet side of the vapor pump and the air to liquid regulator valve. ### Claim 23 A method of operating a vapor recovery system that recovers vapors expelled from a vehicle during refueling at a fuel dispensing point and returns the vapors to an underground storage tank through a vapor flow path that is in fluid communication with an air to liquid regulator valve and a vapor pump driven by a variable speed motor, comprising: dispensing fuel into the vehicle through the fuel dispensing point; regulating an amount of vapor that is recovered through the fuel dispensing point with the air to liquid regulator valve in proportion to the fuel dispensed into the vehicle; detecting a parameter of the vapor recovery system, the parameter being related to rotational torque of the vapor pump; determining a rate of rotation of the vapor pump; comparing the detected parameter of the vapor recovery system to a look-up table of stored constants derived from measuring rotational torque of the vapor pump at various rates of rotation; and adjusting the detected parameter of the vapor pump such that the rotational torque of the vapor pump is substantially constant so that a substantially constant pressure is maintained at an inlet to the vapor pump. ### Claim 24 (depends on 23) The method of claim 23, wherein the detected parameter is determined by measuring a current developed in a non-energized winding of the variable speed motor that drives the vapor pump.