ES2702811T3 - Steam recovery pump and fuel distributor - Google Patents

Abstract

A steam recovery pump for a fuel distribution unit, comprising a pump housing (2) with a first chamber (3) and a second chamber (4), each chamber (3, 4) having a valve steam inlet (5, 7) and a steam outlet valve (6, 8), respectively, the chambers (3, 4) being separated by a mobile piston (9) arranged to decrease and repeatedly increase the volumes of the chambers (3, 4), characterized by a controllable steam flow passage (10) that connects the first chamber (3) with the second chamber (4), for transporting steam from one of the chambers to the other, wherein the controllable steam flow passage (10) comprises a controllable means (15, 11, 11a, 11b, 19a, 19b) adapted to carry out a valve effect, and in which the controllable means is different from the respective steam outlet valves (6, 8).

Description

DESCRIPTION

Steam recovery pump and fuel distributor

Technical field

The present invention relates to a steam recovery pump and fuel distributor for the efficient recovery of fuel vapor from a tank of a vehicle.

Background technique

During the filling of the fuel tank of a motor vehicle, a common measure is to recover the vapor that escapes from the tank during filling with liquid fuel. This measure is taken for both environmental and safety reasons, since fuel vapors are flammable and constitute a health hazard. Vapor recovery is achieved, for example, by the provision of a steam suction nozzle next to the fuel distribution nozzle of a pistol grip which is used to fill the tank with fuel. The steam is then removed from the tank during filling, at a certain rate, which is often controlled by means of the standard rate. Vapor recovery systems typically comprise a pump for the removal of fuel vapor, from the vehicle tank, by means of suction and feeding back to the fuel container from which the fuel is fed to the vehicle. This mutual exchange of steam / fuel is carried out continuously when a vehicle is filled with fuel.

US Pat. No. 3,826,291, for example, discloses a filling system for vehicle fuel, said system comprises means for recovering fuel vapor. The system has a fuel pump and a fuel meter with an outlet stem that is connected to a fuel vapor pump that draws steam from the vehicle tank. The connection is by means of sprockets in such a way that the volume of fuel distributed corresponds to the volume of steam extracted. Piston pumps driven by cranks are used, for example, and the movement of the piston is used only on one side, ie the piston is single acting.

US Pat. No. 5,123,817 discloses another filling system, where a double acting piston pump is used as a steam pump. A common piston rod is connected between the piston pump and a fuel pump, which allows coordinated direct operation of the fuel pump and the steam pump.

US Patent 4,223,706 discloses a similar construction of a filling system where a flow of fuel through a hydraulic motor initiates the return flow of steam through a steam pump. In this construction, a direct operation, that is, a common drive rod, is available between the hydraulic motor and the steam pump. An overflow valve is arranged between the inlet opening of the steam pump and the fuel container of the filling system, to equalize the pressure changes in the system. US Pat. No. 5,106,268 discloses an electromagnetic reciprocating pump that maintains the outlet pressure at a pre-set value comprising a pressure sensor for detecting the actual output pressure of the electromagnetic reciprocating pump and means for the feedback control of the frequency of the reciprocating movement and, if necessary, its tracing of the electromagnetic actuating means based on the deviation of the preset outlet pressure of the actual output pressure.

WO 93/16297 discloses a hydraulic motor apparatus and a method that converts pulsed electromagnetic energy into mechanical force and movement. A reciprocating piston in a cylinder chamber acts on a fluid that is sensitive to pulsed electromagnetic energy. The cylinder chamber acts on a fluid that is sensitive to pulsed electromagnetic energy. The cylinder chamber is provided with inlet and outlet ports with control valve which are hydraulically coupled to a hydraulic motor. The piston has embedded permanent magnets that act in conjunction with the pulsating electromagnets to produce the action of reciprocating motion.

US Patent 2005/053490 discloses an oscillating piston unit for a vacuum pump with a piston, having two piston sections and an intermediate zone provided with a drive magnet. The cylinder sections receive in a sliding manner the piston sections. An annular recess is defined between the cylinder sections in a central fork. The recess provides space for movement of the drive magnet. An electromagnetic unit surrounding the piston includes fork components and the coils located on the sides of said central fork.

US Patent 5,957,113 discloses a fuel vapor recovery apparatus for automobiles that includes a canister for cooling and condensing the fuel vapor generated in the fuel tank and a membrane separation means for separating the fluid fuel vapor from the boat. The invention also provides a membrane separation means for separating the fuel vapor from a canister storing the fuel vapor in a fuel rich mixture and a means for liquefaction and condensation of this separate rich fuel mixture.

A problem associated with the prior art is relatively high production costs due to complex arrangements. Maintenance is cumbersome and many of the techniques are sensitive to vapor leakage beyond the piston. Another problem is that some of the arrangements are quite bulky and need a large amount of space when mounted within a fuel distribution unit.

Summary of the invention

An object of the present invention is to provide an improvement of the prior art techniques and of the prior art, which is achieved by means of a steam recovery pump having a first chamber and a second chamber and a steam flow passage connecting the first camera with the second camera

A particular object is to provide a double-action vapor recovery pump incorporating a means that facilitates effective control of the double action effect.

Other objects and advantages which will be apparent from the following description of the present invention are achieved by means of a steam recovery pump and a fuel distribution unit according to the respective independent claims. Preferred embodiments are defined in the dependent claims.

Accordingly, a vapor recovery pump is provided for a fuel distribution unit, comprising a pump housing with a first chamber and a second chamber, each chamber having a steam inlet valve and a steam valve. steam outlet, respectively, the chambers are separated by a movable piston arranged to decrease and increase the volumes of the chambers repeatedly. A controllable steam flow passage connects the first chamber with the second chamber, for transporting steam from one of the chambers to the other.

The steam recovery pump according to the invention is advantageous in that both sides of the steam recovery pump can be used for steam transport, which makes the pump more insensitive to steam leakage beyond the steam. piston. Another advantage is that the pump rate of the vapor recovery pump can be controlled by controlling the steam flow path. By a step of controllable steam flow it is meant that the passage is controllable with respect to the amount of vapor that can be transported from one of the chambers to the other, ie the size of an opening in the flow path of Steam can be varied. In addition, the direction of steam flow can be controlled.

The steam flow passage may be arranged in the piston, and extend from one of the chambers, through the piston, to the other chamber. Alternatively, the vapor flow passage can be formed by the inclination of the piston, to allow steam to pass from one of the chambers, between the piston and the pump housing, to the other of the chambers. As another alternative, the steam flow passage may be arranged external to the first chamber and the second chamber. These techniques are advantageous in that each offers a simple way to provide an opening between the two chambers.

The piston may comprise a magnetic device, for facilitating convenient control of the piston. Preferably, the magnetic device is either an electromagnet, a permanent magnet or a combination thereof.

The movable piston may have a first side facing the first chamber and a second side facing the second chamber, and an electromagnetic control means may be provided to move the piston by altering a magnetic field, and the magnetic device it can be arranged between the two sides of the piston, which provides a compact design of the vapor recovery pump.

Each of the two sides of the piston can pass a common point along the direction of movement of the piston, when the volumes of the chambers decrease and increase repeatedly, which results in a higher pumping efficiency in relation with the effective total size of the camera.

The pump housing can comprise coils fed by a current for the movement of the piston, which also provides a compact design.

In one embodiment, the vapor flow passage can be configured to be substantially open when the piston decreases the volume of the first chamber, and to be substantially closed when the piston increases the volume of the first chamber, each of the valve of exit from the second chamber and the inlet valve of the first chamber will be essentially open when the vapor flow passage is substantially closed. This is advantageous in that the pump can be used basically as a single side pump, without causing excessive pressure buildup in any of the chambers.

The steam flow passage may comprise a controllable valve and a control unit for controlling the flow of steam through the steam flow passage, and the direction of the steam through flow may be selected for the controllable valve, which further increases the control possibilities of the steam recovery pump.

An overflow valve can be connected to both chambers. A third chamber defining a vacuum may be connected, via a controllable valve, to either the first chamber and the second chamber. Both characteristics are advantageous in that the excessive accumulation of pressure in the chambers is avoided.

The steam recovery pump may further comprise a first steam line connected to the inlet valve of the first chamber, a second steam line connected to the outlet valve of the first chamber, a third steam line connected to the valve of entrance of the second chamber, a fourth steam line connected to the outlet valve of the second chamber, and a steam circulation line comprising a valve and connecting any of the first steam line with the second steam line and the third steam line with the fourth steam line. This further increases the control possibilities of the pump, since the steam can be circulated inside a chamber.

According to another aspect of the invention, there is provided a fuel distribution unit for refueling vehicles, comprising a vapor recovery pump incorporating any of the features described above, in which a steam suction nozzle it is connected to at least one of the two chambers through a steam flow line, for the transport of flammable fuel vapor. The fuel distribution unit according to the invention is, inter alia, advantageous in that it has a compact vapor recovery pump which offers a flexible regulation of the vapor rate recovered through the steam suction nozzle.

The steam suction nozzle may be connected to the first chamber through a first steam flow line, and a second steam suction nozzle may be connected to the second chamber through a second steam flow line, which reduces the number of components in the fuel distribution unit.

The fuel distribution unit may further comprise a fuel distribution nozzle disposed in the steam suction nozzle, a fuel meter configured to measure a quantity of fuel distributed from the fuel distribution nozzle, and a control device configured to regulate the vapor recovery pump so that the amount of vapor recovered corresponds substantially to the amount of fuel distributed. Consequently, this results in fairly effective control of the vapor recovery pump.

The fuel distribution unit may further comprise a detector configured to send a signal representative of the hydrocarbon content of the fuel vapor, the control device is configured to receive the signal and to prevent steam recovery, if the hydrocarbon content of the fuel Fuel vapor is below a specific level. This is advantageous in that the vapor recovery pump is not operated when a user fuels a vehicle equipped with an on-board refueling vapor recovery system.

BRIEF DESCRIPTION OF THE DRAWINGS

Next, embodiments of the present invention will be described, by way of example, with reference to the accompanying schematic figures, in which

Fig. 1 is a schematic view of a vapor recovery pump according to a first embodiment of the invention,

Fig. 2 is a schematic view of the steam recovery pump according to the invention comprising a magnetic control means,

Fig. 3 is a schematic view of a vapor recovery pump according to a second embodiment of the invention,

Fig. 4 is a schematic view of a vapor recovery pump according to a third embodiment of the invention,

Fig. 5 is a schematic view of the vapor recovery pump according to the invention comprising several means for reducing the pressure in a chamber of the vapor recovery pump, and Fig. 6 is a unit of distribution of fuel according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Fig. 1 illustrates a vapor recovery pump 1 having a pump casing 2 with the first chamber 3 which is separated from a second chamber 4 by a piston 9 which is movable along a main axis A of the pump 1. The volume of each chamber 3, 4 depends on the location of the piston 9, but the total volume of the chambers 3, 4 is constant. The first chamber 3 has an inlet valve 5 and an outlet valve 6, and the second chamber 4 has a corresponding inlet valve 7 and a corresponding outlet valve 8.

A first steam inlet line 20 is connected to the inlet valve 5 of the first chamber 3 and a first steam outlet line 21 is connected to the outlet valve 6 of the first chamber 3, while a second steam line 21 is connected to the outlet valve 6 of the first chamber 3. Steam inlet 22 is connected to the inlet valve 7 of the second chamber 4 and a second steam outlet line 23 is connected to the outlet valve 8 of the second chamber 4.

The piston 9 has a magnetic device 11 disposed between a first side 12 and a second side 13 of the piston 9. Preferably, the magnetic device 11 is a permanent magnet or an electromagnet.

An electromagnetic control means 14, which will be described later, during the operation of the pump 1 induces an electromagnetic field that repeatedly and alternately attracts the magnetic device 11 to a first side 43 of the pump 1 and to a second side 44 of the pump 1, which causes an increase and an alternating decrease in the volume of the chambers 3, 4. The piston 9 moves back and forth along the axis A, which means that each side 12, 13 of the piston it goes through a common point P on the axis.

A steam flow passage 10 is connected to the first chamber 3, near the first side 43 and to the second chamber 4 near the second side 44. The steam flow passage has a valve 15 which is controlled by a control unit 16. with respect to the amount of vapor that the steam flow passage 10 can pass, and in what direction. The control unit 16 can adjust the valve 15 to be fully open, fully closed, or to an opening degree ranging from fully open to fully closed. The control unit 16 can also establish the direction of the through flow of the valve 15. To achieve this, the valve 15 preferably comprises a first check valve (not shown) allowing the passage of steam only from the first chamber 3 to the second chamber 4, and a second check valve (not shown) that allows steam to pass only from the second chamber 4 to the first chamber 3. Each check valve can be selectively opened or closed by means of the control unit 16.

When the valve 15 is fully closed the pump 1 acts as a conventional double-sided pump. However, when the valve 15 allows a flow of vapor from the first chamber 3 to the second chamber 4 through the steam flow passage 10, and when the piston 9 moves towards the first side 43, then the outlet valve 6 of the first chamber 3 and the inlet valve 7 of the second chamber 4 remains closed during operation (since the pressure levels necessary to open these valves 6, 7) are not reached. When the piston 9 thereafter moves to the second side 44, the inlet valve 5 of the first chamber 3 opens to let the steam enter the first chamber 3, while the outlet valve 8 of the second chamber 3 chamber 4 opens to let steam out of the second chamber 4.

When the valve 15 allows a flow of vapor from the second chamber 4 towards the first chamber 3 through the steam flow passage 10, and when the piston 9 moves towards the second side 44, then the outlet valve 8 of the second chamber 4 and the inlet valve 5 of the first chamber 3 remain closed during operation (since the pressure levels necessary to open these valves 5, 8) are not reached. When the piston 9 thereafter moves towards the first side 43, then the inlet valve 7 of the second chamber 4 opens to let the steam enter the second chamber 4, while the outlet valve 6 of the first chamber 3 opens to let steam out from the first chamber 3.

It is therefore possible to select which side of the pump will draw steam from a steam source.

The pump 1 can also be used while the steam flow passage 10 is kept closed. In this case, the operating mode is in accordance with what is presented below.

When the volume of the first chamber 3 increases, the volume of the second chamber 4 is reduced. This causes a relatively lower pressure level in the first chamber 3, which causes its inlet valve 5 to open to let in the steam, while causing a relatively higher pressure level in the second chamber 4, which causes its outlet valve 8 to open to let out steam. Correspondingly, when the volume of the first chamber 3 is decreased, the volume of the second chamber 4 is increased, while causing a relatively lower level of pressure in the second chamber 4, which causes its inlet valve 7 it opens to let the steam in, and a relatively higher pressure level is caused in the first chamber 3, which causes its outlet valve 6 to open to let the steam out.

The described operating mode can be used, eg, when two fuel distribution guns with steam recovery nozzles are operated at the same time as described in connection with Fig. 6 below.

With reference to Fig. 2, the electromagnetic control means 14 has a plurality of coils 37 arranged around the pump casing 2. Preferably, the coils 37 are integrated in the pump casing 2. During the operation of the pump 1, the electric currents are fed through the coils 37, which generates a magnetic field that attracts the piston 9, or more specifically, attracts the magnetic device 11 in the piston 9. By feeding the electric currents through the coils near the first side 43 of the pump 1, the piston 9 moves towards the first side 43. When the piston 9 is near the first side 43, the electric currents that are fed through the coils near the second side 44 of pump 1, what which causes the piston to move to the second side 44. By repeatedly and rapidly altering the current levels in the coils 37, the piston moves back and forth.

With further reference to Fig. 3, in a second embodiment of the pump 1, the flow passage and the valve 15 are incorporated in the piston 9. The control options (open, closed, through flow direction) of the valves in this embodiment are identical to the valves of the previous embodiment. However, the valve 15 preferably comprises the opening and closing members, which define the control options which in turn are susceptible to a magnetic attraction force. The control of the opening and closing members is carried out by means of a magnetic field generated in a suitable manner by the electromagnetic control means 14.

With further reference to Fig. 4, in a third embodiment of the pump 1, the piston 9 can be tilted such that a flow passage, or gap, is formed between the housing 2 and the piston 9, which allows steam to pass directly from one chamber to the other. The functional effect of the inclination corresponds to the functional effect of the valve 15 that was previously discussed. When the piston has to allow the passage of steam from one chamber to the other, it is inclined, otherwise it is not. This means that the piston 9 tilts when it moves in one direction, and unlatches when it moves in the other direction. The inclination is preferably achieved by means of the arrangement of two magnetic devices 11a and 11b on opposite sides of the piston, and by means of the application, by the electromagnetic control means 14, of asymmetric magnetic attraction forces suitable for these magnetic devices 11a , 11b.

With further reference to Fig. 5, an overflow valve 17 is connected, through a steam flow line, to both the first chamber 3 and the second chamber 4. If the pressure in one of the chambers 3, 4 for some reason exceeds an undesirable level, the overflow valve 17 is opened to prevent the pump 1 from being damaged by excessive pressure levels.

In one embodiment, the first chamber 3 is connected to a third chamber 18 through a controllable valve 19a, and the second chamber 4 is connected to the third chamber 18 through another controllable valve 19b. To reduce the relative pressure level in either the first chamber 3 or the second chamber 4, the corresponding valves 19b 19a are opened.

To allow steam regulation in the first chamber 3, a first steam recirculation line 24 comprising a controllable valve 30a is connected to the first steam inlet line 20 and to the first steam outlet line 21. In a way corresponding a second steam recirculation line 25 comprising a controllable valve 30a connects the second steam inlet line 22 to the second steam outlet line 23.

The valves 19a, 19b, 30a and 30b are, for example, connected to and controlled by the control unit 16.

With reference to Fig. 6, a fuel distribution unit 36 incorporates a vapor recovery pump 1 according to the above description. The fuel distribution unit 36 has a first conventional fuel distribution gun 40 with a fuel distribution nozzle 27 and a vapor recovery nozzle 26. The fuel distribution nozzle 27 is, through a first line of fuel 31 having a fuel meter 32, in fluid communication with an underground fuel storage tank 42.

The fuel distribution unit 36 also has a second fuel distribution gun 41 with a fuel distribution nozzle (not shown) and a vapor recovery nozzle 28. The fuel distribution nozzle is, through a second fuel line (not shown) that has a fuel meter (not shown), in fluid communication with an underground fuel storage tank 42.

The steam recovery nozzle 26 of the first gun 40 is, via a first steam recovery line 33, connected to the inlet valve of the first chamber of the pump 1. The steam recovery line 33 has a detector 39a which detects the level of hydrocarbons in the first steam recovery line 33. The vapor recovery nozzle 28 of the second gun 41 is, through a second steam recovery line 34, connected to the inlet valve of the second chamber of the pump 1. The vapor recovery line 33 also has a hydrocarbon detector 39b for detecting the level of hydrocarbons in the second vapor recovery line 34.

The outlet valves of both chambers of the vapor recovery pump are connected to the fuel storage tank 42 through suitable steam flow lines.

A control device 38 is connected to the fuel gauges, to the hydrocarbon detectors and to the control unit of the steam recovery pump 16. Optionally, the control unit of the steam recovery pump 16 is integrated in the control device 38.

During the filling of a vehicle by means of the first gun 40, the rate of distributed fuel is measured by the fuel meter 32. The control device monitors the distributed fuel rate and sends a signal to the vapor recovery pump 1 to set the vapor recovery rate, or the pump rate, to be equal to the rate of fuel distribution. If the detector 39a detects a predetermined low level of hydrocarbon content, the vapor recovery pump is stopped. During the filling of a vehicle by means of the second gun 41, a corresponding operation is carried out.

When only one of the guns 40, 41 is used to distribute fuel, the described steam flow passage between the two chambers of the steam recovery pump 1 is open, so that the steam is drawn into the chamber having its Inlet valve connected to the steam recovery line that belongs to the gun that is being used. When the two pistols 40, 41 are used at the same time, the flow passage between the two chambers is closed.

Claims (20)

A steam recovery pump for a fuel distribution unit, comprising a pump housing (2) with a first chamber (3) and a second chamber (4), each chamber (3, 4) having a steam inlet valve (5, 7) and a steam outlet valve (6, 8), respectively, the chambers (3, 4) being separated by a movable piston (9) arranged to decrease and increase repeatedly the chamber volumes (3, 4), characterized by a controllable steam flow passage (10) that connects the first chamber (3) with the second chamber (4), for transporting steam from one of the chambers to the chamber. another, wherein the controllable steam flow passage (10) comprises a controllable means (15, 11, 11a, 11b, 19a, 19b) adapted to carry out a valve effect, and wherein the controllable medium is different from the respective steam outlet valves (6, 8). A steam recovery pump according to claim 1, wherein the steam flow passage (10) is disposed in the piston (9), and extends from one of the chambers, through the piston ( 9), to the other of the cameras. 3. A steam recovery pump according to claim 1, wherein the vapor flow passage (10) is formed by means of the inclination of the piston (9), to allow the passage of vapor from one of the cameras, between the piston (9) and the pump casing (2), to the other of the chambers. A steam recovery pump according to claim 1, wherein the steam flow passage (10) is disposed external to the first chamber (3) and to the second chamber (4). 5. A vapor recovery pump according to any one of claims 1 to 4, wherein the piston (9) comprises a magnetic device (11). 6. A steam recovery pump according to claim 5, wherein the movable piston (9) has a first side (12) facing the first chamber (3) and a second side (13) facing the second. chamber (4), the electromagnetic control means (14) being provided for moving the piston (9) by means of the alteration of a magnetic field. A steam recovery pump according to claim 6, wherein the magnetic device (11) is disposed between the two sides (12, 13) of the piston (9). A steam recovery pump according to claim 6 or 7, wherein each of the two sides (12, 13) of the piston (9) passes through a common point (P) along the length of the direction of movement of the piston (9), when the volumes of the chambers (3, 4) decrease and increase repeatedly. A steam recovery pump according to any one of claims 1 to 8, wherein the pump casing (2) comprises coils (37) fed by a current for the movement of the piston (9). A steam recovery pump according to any one of claims 1 to 9, wherein the steam flow passage (10) is configured to be substantially open when the piston (9) decreases the volume of the first chamber (3), and be substantially closed when the piston (9) increases the volume of the first chamber (3), the outlet valve (8) being the second chamber (4) and the inlet valve (5) of the first chamber (3), each essentially open when the steam flow passage (10) is substantially closed. 11. A steam recovery pump according to any one of claims 1 to 10, wherein the steam flow passage (10) comprises a controllable valve (15). 12. A steam recovery pump according to claim 11, wherein the steam through flow direction can be selected for the controllable valve (15). 13. A steam recovery pump according to any one of claims 1 to 12, further comprising a control unit (16) for controlling the flow of steam through the steam flow passage (10). A vapor recovery pump according to any one of claims 1 to 13, wherein an overflow valve (17) is connected to the two chambers (3, 4). A vapor recovery pump according to any one of claims 1 to 14, wherein a third chamber (18) defining a vacuum is connected, through a controllable valve (19a; 19b), to any of the first chamber (3) and the second chamber (4). 16. A vapor recovery pump according to any one of claims 1 to 15, further comprising a first steam line (20) connected to the inlet valve (5) of the first chamber (3), a second steam line (21) connected to the outlet valve (6) of the first chamber (3), a third steam line (22) connected to the inlet valve (7) of the second chamber (4), a fourth steam line (23) connected to the outlet valve (8) of the second chamber (4), and a steam circulation line (24, 25) comprising a valve (30a, 30b) and connecting any of the first steam line (20) with the second steam line (21) and the third steam line (22) ) with the fourth steam line (23). 17. A fuel distribution unit for refueling vehicles, comprising a vapor recovery pump (1) according to any one of claims 1 to 16, wherein a steam suction nozzle (26) is connected to at least one of the two chambers (3; 4) through a steam flow line (33), for transporting fuel vapor. 18. A fuel distribution unit according to claim 17, wherein said steam suction nozzle (26) is connected to the first chamber (3) through a first steam flow line (33), and a second steam suction nozzle (28) is connected to the second chamber (4) through a second steam flow line (34). 19. A fuel distribution unit according to claim 17 or 18, further comprising a fuel distribution nozzle (27) disposed in the steam suction nozzle (26), a fuel meter (32) configured for measuring a quantity of fuel distributed from the fuel distribution nozzle (27), and a control device (38) configured to regulate the vapor recovery pump (1) so that the amount of vapor recovered corresponds substantially to the amount of distributed fuel. 20. A fuel distribution unit according to claim 19, further comprising a detector (39a) configured to send a signal representative of the hydrocarbon content of the fuel vapor, the control device (38) being configured to receive the signal and to prevent steam recovery, if the hydrocarbon content of the fuel vapor is below a specific level.