Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
  • B67D—DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
  • B67D7/00—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
  • B67D7/04—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes for transferring fuels, lubricants or mixed fuels and lubricants
  • B67D7/0476—Vapour recovery systems
  • B67D7/0478—Vapour recovery systems constructional features or components
  • B67D7/048—Vapour flow control means, e.g. valves, pumps
  • B67D7/0482—Vapour flow control means, e.g. valves, pumps using pumps driven at different flow rates
  • B67D7/0486—Pumps driven in response to electric signals indicative of pressure, temperature or liquid flow

Definitions

• the present invention relates to a system for recovering hydrocarbon vapors released from motor vehicle tanks during the delivery of liquid fuel through at least one distribution pipe.
• the distribution lines terminate in a flexible hose fitted at one end with a gun which the user introduces into the neck of the tank of his vehicle.
• the recovery of vapors therefore consists, in principle, in sucking out of the neck a volume of vapor which at all times must be equal to the volume of liquid fuel delivered.
• the dispensing gun is equipped with a sleeve penetrating into the outlet port of the vehicle tank, and into which opens the upstream end of a recovery pipe on which is placed a suction pump which discharges the recovered hydrocarbon vapors to the liquid fuel storage tank.
• One known way to avoid these drawbacks is to insert a gas flow meter into the recovery line, possibly in association with a pressure sensor to control the speed of rotation of the circulation pump or the opening of a valve in order to '' obtain the desired vapor flow rate.
• the technical problem to be solved by the object of the present invention is to propose a system for recovering hydrocarbon vapors released from motor vehicle tanks during the delivery of liquid fuel through at least one distribution pipe, system which would allow a good proportionality between the flow of vapors to be recovered and the speed of rotation of the circulation pump, such as a vane, gear or rotary piston pump, without using a servo loop for this complex and expensive, such as that previously described with reference to the state of the art.
• the solution to the technical problem posed consists, according to the present invention, in that said system comprises a recovery line, a power pump placed on said recovery line, and a metering pump driven by a motor at a substantially rotational speed. proportional at the volume flow rate of the liquid fuel delivered in the distribution line, said metering pump being mounted in series with said power pump by means of a differential pressure regulator capable of maintaining a low pressure difference between the outlet and the inlet of the metering pump, so as to obtain a volume flow of vapors substantially proportional to the speed of rotation imposed by said motor.
• the metering pump is made metrological by the presence at its terminals of the regulator-regulator which requires the said pump to operate under a very low differential pressure and if possible zero, the internal leaks becoming negligible.
• the volume flow of vapors being proportional to the speed of rotation of the engine which itself is proportional to the volume flow of liquid fuel, it is therefore understandable that it is possible to achieve the desired equality between the flows of vapors and of liquid, and this whatever the flow rate, the nature of the gas, the state of wear of the pump or the hydraulic resistance of the recovery line.
• the metering pump can only supply a limited power to ensure the circulation of vapors. It must be helped in this by the power pump, capable of ensuring in all circumstances at least the maximum flow requested.
• the metering pump is therefore capable of metrologically metering the volumes of vapors passing through the entire recovery system and in a way playing a role comparable to that of a flow control valve but with, however, much higher metrological qualities thanks to the lack of relaxation.
• the drive motor of the metering pump provides a power, a fraction of which is intended to overcome the mechanical friction of the pump, the rest being used to circulate and transfer the recovered vapors under very low differential pressure and therefore at very low power.
• Two embodiments of the recovery system according to the invention can be envisaged.
• said metering pump is mounted in series downstream of the power pump.
• a pressure regulator is disposed downstream of the metering pump and of said differential pressure regulator-regulator.
• said metering pump is mounted in series upstream of the power pump, a pressure regulator being arranged upstream of the metering pump and of said differential pressure regulator-regulator.
• This latter embodiment has the advantage that, said distribution pipes being multiple, the power pump is unique and placed on a portion common to the respective recovery pipes, downstream of said differential pressure regulators.
• a preferred assembly of the recovery system of the invention leading to a simple and inexpensive embodiment consists in that said power pump and said storage pump are driven by a common motor at a speed of rotation substantially proportional to said volume flow rate. of liquid fuel delivered, the power pump having a cyclic volume greater than the cyclic volume of the metering pump.
• Figure 1 is a diagram of a first embodiment of the recovery system according to the invention.
• Figure 2 is a diagram of a second embodiment of the recovery system according to the invention.
• Figure 3 is a diagram of the recovery system of Figure 2, with multiple distribution and recovery lines.
• FIG. 4 is a diagram of an alternative embodiment of the recovery system of FIG. 1.
• FIG. 1 shows a system for recovering the hydrocarbon vapors released from vehicle tanks automobiles during the delivery of liquid fuel through a distribution line 19.
• the upstream end of said distribution pipe 19 is immersed in a tank 1 for storing liquid fuel, which is sucked in by a pump 2 delivering a volume flow rate Q v .
• the liquid fuel passes through a measurer 3, placed in the distributor, capable of producing, for example, the rotational movement of an axis at a substantially proportional angular speed Q v .
• a pulse generator 4 coupled to the measurer 3, such as an optical disc, supplies pulses whose frequency N is proportional to the volume flow rate.
• the distribution pipe 19 takes the form of a flexible pipe terminated by a gun 5 of the vapor recovery type in the sense that it is provided with a sleeve, not shown, charged with avoid the dissipation into the atmosphere of the hydrocarbon vapors which emanate from the tank as it fills with fuel.
• Said gun is the starting point of a recovery pipe 6 on which is placed a power pump 7 which can be of any type, with vanes for example as in FIG. 1.
• Said power pump 7 is actuated by a motor 8 at an angular speed ⁇ so as to supply at all times almost all of the power necessary for the circulation of the vapors to be recovered, without necessarily having good metrological quality as regards its flow rate ratio. / speed ⁇ of rotation.
• the angular speed ⁇ is maintained at a value such that: ⁇ V ⁇ > ⁇ 0 q vo ⁇ ettp being respectively the density of the hydrocarbon vapors at atmospheric pressure p 0 and at the inlet of the pump 7, and q v0 the flow of vapors at atmospheric pressure which one seeks to make equal to the flow Q v of liquid fuel in the distribution line 19.
• Downstream of the power pump 7 is mounted in series a metering pump 10 of the volumetric type driven by a motor 1 1 controlled by an amplifier 14 capable of transforming the impulse signals from the generator 4 into power signals capable of supplying the motor 1 1, for example of the stepping type, and rotate it at an angular speed ⁇ thereby proportional to the volume flow rate Q v of the liquid fuel delivered in the distribution line 19.
• the metering pump 10 is mounted in downstream series on the power pump 7 by means of a differential pressure regulator 9, of a conventional model, which receives from said pump 7 of power of the hydrocarbon vapors under a pressure P greater than the initial pressure p 0 .
• the differential pressure ⁇ p between the inlet and the outlet of the metering pump 10 is maintained at a very low value ⁇ 6. More specifically, the pressure in the chamber B of the regulator-regulator 9 takes values between p'- £ and p '+ £, p' being the pressure at which the metering pump 10 delivers the vapors to the storage tank 1 where the pressure p 'prevails, down to the downstream pressure drop.
• the power pump 7 being able to provide a mass flow greater than that evacuated by the metering pump 10, the chamber A of regulator-regulator 9 is always under pressure P> p 0 and the expansion from P to p ' ⁇ 6 can always be done between chambers A and B at the level of the regulating valve.
• the metering pump 10 working under very close upstream and downstream pressures, acquires a very good metrological quality, the internal leaks being canceled.
• downstream power pump 7 will always provide enough pressure to discharge the vapors when the downstream pipe 13 is hydraulically resistant.
• foq vo ⁇ v fi
• the vapor recovery system of Figure 2 can be easily extended in the case of a plurality of distribution lines.
• the power pump 7 is unique and placed on a common portion 6 to the pipes 6a, 6b of recovery, downstream of the pressure regulators 9a, 9b of differential pressure.
• FIG. 4 shows an alternative embodiment of the recovery system of the invention in which the power pump 7 and the metering pump 10 are driven by a common motor 17 at a speed ⁇ -> of rotation substantially proportional to the volume flow Q v of liquid fuel delivered.
• the cyclic volume power pump 7 V flows into the regulator 9 at the level of the chamber A.
• the chambers B and C are connected respectively upstream and downstream of the pump 10 which thus works at very low differential pressure and whose the cyclic volume is v less than V.
• the metering pump 10 does not evacuate, under these conditions, as much vapor as the pump 7 is capable of supplying, an overpressure P> p Q is established in the chamber A of the regulator-regulator 9 and its valve can relax the vapors from P to p "towards the inlet of the metrological pump 10, which operates under the pressure p" with a differential inlet / outlet pressure of Vosine of zero.
• Another advantageous characteristic of the vapor recovery system, object of the invention is the possibility of carrying out a test with air ("dry test" in English) without committing a systematic error due to the differences in viscosity and of molecular mass between the air and the air + hydrocarbon vapor mixture.

Landscapes

• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Loading And Unloading Of Fuel Tanks Or Ships (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Processing Of Solid Wastes (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

Country Status (6)

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• 1995
  • 1995-07-06 FR FR9508194A patent/FR2736340B1/fr not_active Expired - Fee Related
• 1996
  • 1996-07-02 US US08/793,650 patent/US5878790A/en not_active Expired - Fee Related
  • 1996-07-02 EP EP96924923A patent/EP0779876B1/de not_active Expired - Lifetime
  • 1996-07-02 AT AT96924923T patent/ATE174309T1/de not_active IP Right Cessation
  • 1996-07-02 WO PCT/FR1996/001031 patent/WO1997002208A1/fr active IP Right Grant
  • 1996-07-02 DE DE69601122T patent/DE69601122D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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