Abstract
A fueling environment's safety is improved by adding static charge
sensors to the fuel dispenser and its peripherals. The static charge
sensors detect static charge proximate the fuel dispenser and provide
an indication of the static charge to a threshold detector. If the
static charge is above a predetermined threshold, one or more safety
devices may be activated to disperse or reduce the amount of hydrocarbon
vapors proximate the fuel dispenser. Reduction in the amount of hydrocarbon
vapors proximate the fuel dispenser helps reduce the risk of harm
from the static charge.
Claims
1. A fuel dispenser that dispenses fuel from a storage tank, comprising:
a static charge sensor adapted to sense static charge levels proximate
the fuel dispenser; and a safety device adapted to operate when the
static charge sensor senses a static charge above a predetermined
threshold.
2. The fuel dispenser of claim 1, further comprising a dispenser
controller operatively associated with the static charge sensor
and the safety device.
3. The fuel dispenser of claim 1, wherein the safety device comprises
a fan.
4. The fuel dispenser of claim 3, wherein a position of the fan
is selected from the group consisting of: a fuel dispenser face,
a fuel dispenser canopy, a fuel dispenser side, proximate an edge
of a fuel dispenser body, and removed from the fuel dispenser.
5. The fuel dispenser of claim 1, wherein the safety device is
selected from the group consisting of: a fuel control valve, a fuel
dispenser pump, a fueling environment fuel pump, and an alarm.
6. The fuel dispenser of claim 4, further comprising a dispenser
controller, the dispenser controller adapted to perform a function
in response to a static charge being sensed, the function selected
from the group consisting of: turn off the fuel control valve, turn
off the fuel dispenser pump, turn off the fueling environment pump,
and turn on the alarm.
7. The fuel dispenser of claim 1, wherein the static charge sensor
comprises an electrode adapted to generate a signal when the static
charge is present, an amplifier adapted to amplify the signal to
create an amplified signal, and a threshold detector adapted to
compare the amplified signal to the predetermined threshold.
8. The fuel dispenser of claim 5, wherein the electrode comprises
an electrode with a pointed terminal end.
9. The fuel dispenser of claim 5, wherein the electrode comprises
an electrode with a curved terminal end adapted to concentrate the
static charge so as to produce the signal.
10. The fuel dispenser of claim 1, wherein the static charge sensor
is adapted to provide a signal to a remote controller, and the safety
device is adapted to be activated by the remote controller.
11. The fuel dispenser of claim 1, further comprising a dispenser
housing, and the static charge sensor is positioned in the dispenser
housing.
12. The fuel dispenser of claim 9, wherein the dispenser housing
comprises an edge, and the static charge sensor is positioned proximate
the edge.
13. The fuel dispenser of claim 9, wherein the dispenser housing
comprises a dispenser canopy and the static charge sensor is associated
with the dispenser canopy.
14. The fuel dispenser of claim 1, wherein the static charge sensor
is protected from accidental contact by a physical barrier.
15. The fuel dispenser of claim 1, further comprising a nozzle
that dispenses the fuel, wherein the static charge sensor is positioned
on the nozzle.
16. The fuel dispenser of claim 15, wherein the static charge sensor
is positioned in a cavity within the nozzle, and the static charge
sensor comprises an electrode, a mesh adapted to protect the electrode
from physical contact by a user.
17. The fuel dispenser of claim 12, wherein the cavity is positioned
on an anterior surface of the nozzle.
18. A method of sensing a static charge in a fueling environment,
comprising: associating a static charge sensor with a fuel dispenser
in the fueling environment; sensing static charge levels with the
static charge sensor; and activating a safety device if the static
charge sensor detects a static charge above a predetermined threshold.
19. The method of claim 13, wherein associating a static charge
sensor with a fuel dispenser comprises positioning the static charge
sensor on a fuel dispenser housing.
20. The method of claim 13, wherein associating a static charge
sensor with a fuel dispenser comprises positioning the static charge
sensor on a canopy pillar proximate the fuel dispenser.
21. The method of claim 13, wherein associating a static charge
sensor with a fuel dispenser comprises positioning the static charge
sensor on a canopy positioned over the fuel dispenser.
22. The method of claim 13, wherein associating a static charge
sensor with a fuel dispenser comprises positioning the static charge
sensor on a crash barrier proximate the fuel dispenser.
23. The method of claim 13, wherein associating a static charge
sensor with a fuel dispenser comprises associating a static charge
sensor comprising an electrode with the fuel dispenser.
24. The method of claim 18, wherein associating a static charge
sensor comprising an electrode with the fuel dispenser comprises
associating a static charge sensor comprising an electrode with
a pointed terminal end with the fuel dispenser.
25. The method of claim 18, wherein associating a static charge
sensor comprising an electrode with the fuel dispenser comprises
associating a static charge sensor comprising an electrode with
a J-shaped terminal end with the fuel dispenser.
26. The method of claim 13, wherein activating a safety device
comprises turning on a fan.
27. The method of claim 13, wherein activating a safety device
comprises activating a safety device selected from the group consisting
of: a fuel flow valve, a fuel dispenser pump, a fueling environment
fuel pump, and an alarm.
28. The method of claim 13, further comprising reporting sensed
static charge levels to a dispenser controller.
29. The method of claim 13, further comprising reporting sensed
static charge levels to a remote controller.
30. The method of claim 13, further comprising protecting the static
charge sensor from accidental contact with a physical barrier.
31. A fueling environment comprising: a fuel dispenser comprising
a static charge sensor adapted to sense static charge levels proximate
the fuel dispenser; a safety device; and a controller adapted to
receive sensed static charge levels from the static charge sensor
and activate the safety device.
32. The fueling environment of claim 26, wherein the controller
comprises a dispenser controller.
33. The fueling environment of claim 26, wherein the dispenser
controller is adapted to perform a function in response to a static
charge being sensed, the function selected from the group consisting
of: turn off a fuel control valve, turn on a fan, turn off a fuel
dispenser pump, turn off a fueling environment pump, and generate
an alarm.
34. The fueling environment of claim 26, wherein the controller
comprises a site controller.
35. The fueling environment of claim 28, wherein the site controller
is adapted to perform a function in response to a static charge
being sensed, the function selected from the group consisting of:
turn off the fuel control valve, turn off the fuel dispenser pump,
turn on a fan, turn off the fueling environment pump, and generate
the alarm.
36. The fueling environment of claim 26, wherein the safety device
comprises a fan.
37. The fueling environment of claim 29, wherein the fan is mounted
in a position selected from the group consisting of: a fuel dispenser
face, a fuel dispenser canopy, a canopy pillar, a canopy, and a
lower portion of the fuel dispenser.
38. The fueling environment of claim 26, wherein the safety device
comprises a device selected from the group consisting of: an alarm,
a fuel control valve, a fuel dispenser pump, and a fueling environment
pump.
39. The fueling environment of claim 26, wherein the static charge
sensor is positioned on the fuel dispenser.
40. The fueling environment of claim 26, wherein the static charge
sensor is associated with the fuel dispenser.
41. The fueling environment of claim 26, wherein the static charge
sensor is proximate the fuel dispenser, but not on the fuel dispenser.
42. The fueling environment of claim 33, wherein the static charge
sensor is positioned on a location selected from the group consisting
of: a canopy pillar, a canopy, and a crash barrier.
43. The fueling environment of claim 31, wherein the fuel dispenser
comprises a body comprising an edge and the static charge sensor
is positioned proximate the edge.
44. The fueling environment of claim 31, wherein the fuel dispenser
comprises a dispenser canopy, and the static charge sensor is associated
with the dispenser canopy.
45. The fueling environment of claim 26, wherein the static charge
sensor comprises an electrode adapted to generate a signal if a
static charge is present, an amplifier adapted to receive the signal
and amplify the signal into an amplified signal, and a threshold
detector.
46. The fueling environment of claim 37, wherein the electrode
comprises an electrode with a pointed terminal end.
47. The fueling environment of claim 37, wherein the electrode
comprises an electrode with a J-shaped portion.
48. The fueling environment of claim 26, further comprising a physical
barrier adapted to protect the static charge sensor from accidental
contact.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to fueling environments and
particularly to detecting fields of static electricity generated
by a static charge in the fueling environment.
BACKGROUND OF THE INVENTION
[0002] Fueling environments handle fuels that are dispensed, and
thus safety issues are always of concern. For example, it is possible
that, in the right environmental conditions, there may be enough
of a static electrical charge accumulated to generate a spark. In
normal environments, such a spark shocks the recipient and may provide
some brief period of discomfort. However, in a fueling environment
that has hydrocarbon vapors lingering about the fuel dispensers,
such a spark may be more dangerous.
[0003] Currently, most fuel dispensers display warnings about the
risks associated with static electricity. However, there are currently
no known commercially deployed devices which detect the presence
of an elevated static charge proximate a nozzle of a fuel dispenser
in a fueling environment. In light of the issues associated with
such static charges, there is a need for a device that detects static
charge proximate the fuel dispenser and has the capability to improve
the safety of fuel dispenser users when such a static charge is
detected.
SUMMARY OF THE INVENTION
[0004] The present invention addresses the problems of the prior
art by providing a static charge sensor at various places within
the fueling environment to sense whether a static charge is present.
If a static charge above a predefined threshold is detected by the
static charge sensor, a controller associated with the static charge
sensor may generate an alarm or invoke certain safety measures to
alleviate risks associated with the elevated static charge.
[0005] The static charge sensor is, in a contemplated embodiment,
a wire probe that is connected to an amplifier and threshold detector
circuit. As an electric field is generated by a static charge, the
resulting charge collects on the wire probe, and a current is induced
in the wire. The amplifier amplifies the induced current and provides
the amplified current to a resistive component associated with the
threshold detector circuit. The threshold detector circuit uses
the voltage across the resistive component to determine if the static
charge is above the predefined threshold.
[0006] If the threshold detector circuit determines that the static
charge at the static charge sensor exceeds the predetermined threshold,
the detector circuit causes one or more safety measures to be invoked.
The safety measures include, but are not limited to, shutting off
a flow control valve, shutting off a fueling environment fuel pump,
turning off a dispenser fuel pump, generating an alarm for the site
operator, generating an alarm at a remote location, turning on a
fan to dissipate fuel vapors, and the like. These safety measures
are designed to help limit hydrocarbon vapors, or, at a minimum
alert the user of the risk of a spark, such that if a spark were
to be emitted, there would be a reduced likelihood of a fire or
other damage.
[0007] The static charge sensors of the present invention may be
positioned in a number of places in a fueling environment, including,
but not limited to the nozzle, the edge of the housing of the fuel
dispenser, the face of the fuel dispenser, the canopy of the fuel
dispenser, and the like. The various placements are designed to
increase the likelihood that a static charge will be sensed.
[0008] The static charge sensor is, in a specifically contemplated
embodiment, a wire with a small radius on its terminal end. The
small radius increases field strength to make static charge detection
easier. The wire is protected from being hit accidentally by a grounded
physical barrier such as a grounded wire screen or the like. The
wire screen includes openings large enough to allow some of the
electric field to reach through the screen and impinge upon the
wire. Other static charge sensors are also contemplated.
[0009] Those skilled in the art will appreciate the scope of the
present invention and realize additional aspects thereof after reading
the following detailed description of the preferred embodiments
in association with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying figures incorporated in and forming a part
of this specification illustrate several aspects of the invention,
and together with the description, serve to explain the principles
of the invention.
[0011] FIG. 1 illustrates a fuel dispenser within a fueling environment
with a static charge sensor disposed thereon;
[0012] FIG. 2 illustrates an exemplary static charge sensor positioned
in a nozzle according to one embodiment of the present invention;
[0013] FIG. 3 illustrates a second exemplary static charge sensor
positioned in a nozzle according to a second embodiment of the present
invention;
[0014] FIG. 4 illustrates a side view of the nozzle with the static
charge sensor of FIG. 3;
[0015] FIG. 5 illustrates a circuit diagram of an exemplary static
charge sensor;
[0016] FIG. 6 illustrates a simplified version of a sensor and
detector circuit according to the present invention;
[0017] FIG. 7 illustrates a fuel dispenser with various static
charge sensors according to the present invention;
[0018] FIG. 8 illustrates some exemplary placements for safety
measures according to the present invention;
[0019] FIG. 9 illustrates a first control system to invoke safety-measures
according to the present invention;
[0020] FIG. 10 illustrates a second control system to invoke safety
measures according to the present invention; and
[0021] FIG. 11 illustrates a flow chart describing the methodology
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The embodiments set forth below represent the necessary
information to enable those skilled in the art to practice the invention
and illustrate the best mode of practicing the invention. Upon reading
the following description, and in light of the accompanying figures,
those skilled in the art will understand the concepts of the invention
and will recognize applications of these concepts not particularly
addressed herein. It should be understood that these concepts and
applications fall within the scope of the disclosure and the accompanying
claims.
[0023] The present invention is directed to sensing a static charge
in a fueling environment and invoking one or more safety measures
to minimize risks associated with the detected static charge. To
this end, the present invention positions static charge sensors
at various locations on a fuel dispenser and its peripherals and/or
in the surrounding environs. The static charge sensors provide input
to a threshold detector circuit that determines if any sensor has
detected a static charge above a predetermined threshold. If a static
charge above the predetermined threshold is detected, one or more
safety measures are invoked to alert someone as to the existence
of the static charge to reduce the likelihood of a spark causing
a fire or other damage.
[0024] FIG. 1 illustrates a fuel dispenser 10 that shows one partial
embodiment of the present invention. The fuel dispenser 10 includes
a housing 12, having edges 14, a fuel dispenser canopy 16, a hose
18, and a nozzle 20. An exemplary fuel dispenser 10 may be the ENCORE.RTM.
or the ECLIPSE.RTM. sold by Gilbarco Inc. of 7300 W. Friendly Avenue,
Greensboro, N.C. 27410. The fuel dispenser 10 includes a user interface
22 that connects to electronic components (EC) 24, including a dispenser
controller (.quadrature.P) 26, positioned within an electronics
chamber 28. The user interface 22 has audio and visual components
for conveying information to a user and inputs to accept the user's
instructions. The housing 12 also includes a fuel handling chamber
30 in which a flow control valve 32 and other conventional fuel
handling components 34 (FHC) may be positioned.
[0025] Additionally, some fuel dispensers 10 may include a fuel
dispenser pump 36 (shown dotted), which pumps fuel from an underground
storage tank 38. If the fuel dispenser pump 36 is not present, the
fuel dispenser 10 receives fuel from the underground storage tank
38 via a submersible turbine pump 40 such as the RED JACKET.RTM.
pumps sold by Marley Pump of Veeder-Root of 125 Powder Forest Drive,
Simsbury, Conn. 06070.
[0026] Electronics chamber 28 may be selectively accessed through
a door 42, and fuel handling chamber 30 may be selectively accessed
by a door 44. In normal operation, doors 42 and 44 are locked, as
is well understood. The doors 42 and 44 may be variously sized or
repositioned on the housing 12 as needed or desired. The illustrated
doors 42 and 44 are exemplary and are not intended to be limiting.
[0027] The fuel dispenser 10, and particularly the dispenser controller
26, may communicate with a site controller (SC) 46, which may be
the G-SITE.RTM. sold by Gilbarco. The communication between the
dispenser controller 26 and the site controller 46 may be through
a conventional communication link 48. The submersible turbine pump
40 may communicate with a tank monitor 50 such as a TLR-350R sold
by Veeder-Root. The communication between the submersible turbine
pump 40 and the tank monitor 50 may be through a conventional communication
link 52. The site controller 46 may communicate with the tank monitor
50 as needed or desired. The site controller 46 and/or the tank
monitor 50 may report to an off site location 54 through an off
site communication link 56 if needed or desired. While shown as
a single communication link 56, it should be appreciated that both
the site controller 46 and the tank monitor 50 may each have its
own dedicated communication link to the off site location 54. To
this extent, both the site controller 46 and the tank monitor 50
are referred to herein as site communicators. The site communicators
may communicate to the same or different off site locations 54 as
needed or desired.
[0028] It should be appreciated that different types of fuel dispensers
10 may be used with the present invention, and the exemplary products
described above are not intended to be limiting.
[0029] The fuel dispenser 10 includes one or more static charge
sensors 60. In FIGS. 1-4, the static charge sensor 60 is shown positioned
on the nozzle 20, although other placements are also possible as
explained in greater detail below.
[0030] Two exemplary static charge sensors 60 are presented in
FIGS. 2 and 3, and a cross sectional view of the static charge sensor
60 of FIG. 3 is provided in FIG. 4. The static charge sensor 60
of FIG. 2 comprises a generally hook shaped wire electrode 62 positioned
beneath a wire mesh 64. The wire mesh 64 is coupled to an electric
ground 66. The generally hook shaped wire electrode 62 has a small
radius of curvature 68 around the terminal portion of the hook so
as to concentrate charge on the generally hook shaped wire electrode
62. The concentrated charge on the generally hook shaped wire electrode
62 induces a current in the static charge sensor 60 as explained
below. The generally hook shaped wire electrode 62 may alternatively
be considered to be in a "J" shape. The generally hook
shaped wire electrode 62 is electrically coupled to an electrically
conductive wire 70, which has insulation 72 therearound to form
an insulated wire. It is possible that the element that grounds
the wire mesh 64 forms a twisted pair with the electrically conductive
wire 70 if they may be electrically isolated one from the other
sufficiently. It is further possible that the grounding element
and/or the electrically conductive wire 70 is shielded from electromagnetic
interference if needed or desired.
[0031] The static charge sensor 60 of FIG. 3 is substantially similar
to the static charge sensor 60 of FIG. 2, but in place of the generally
hook shaped wire electrode 62, the static charge sensor 60 of FIG.
3 has a pointed terminal end 74 to form pointed electrode 76. Just
as the generally hook shaped wire electrode 62 concentrates charge,
the pointed electrode 76 also concentrates charge on the pointed
terminal end 74. The concentrated charge induces a current in the
static charge sensor 60 as explained below. Again, the pointed electrode
76 is protected from accidental contact by the wire mesh 64. In
practice, the openings 78 of the wire mesh 64 are large enough to
allow an electric field therethrough, but small enough to prevent
inadvertent physical contact with the static charge sensor 60.
[0032] FIG. 4 illustrates a better example of an electric field
80 passing through the openings 78 of the wire mesh 64. Specifically,
FIG. 4 illustrates a point source 82 of static charge that produces
the electric field 80 (identified by concentric lines). As the electric
field 80 impinges upon the wire mesh 64, the electric field 80 is
scattered. However, some portion of the electric field 80 passes
through the openings 78 (FIGS. 2 and 3) of the wire mesh 64 and
form secondary electric fields 84 within a cavity 86 within which
the pointed electrode 76 is positioned. The secondary electric fields
84 impinge upon the pointed electrode 76 (or the generally hook
shaped wire electrode 62) and cause electrons to shift within the
pointed electrode 76 (or the generally hook shaped wire electrode
62). The movement of the electrons creates a current which may be
measured as explained in greater detail below.
[0033] Static charge sensors 60 may also be mounted in such a manner
as to limit the effects of moisture, which might cause a leakage
path to electrical ground for the electrodes 62 and 76. One contemplated
technique is to mount the electrodes 62 and 76 within a non-hygroscopic
material. Since the material is non-hygroscopic, moisture will not
be retained proximate the electrodes, thereby minimizing risk of
an inadvertent short or corrosion due to lingering moisture. In
the exemplary embodiments, the cavity 86 is positioned on a back
or anterior surface of the nozzle 20. As used herein, the word "anterior"
as applied to the nozzle 20 means the portion of the nozzle 20 that
juts outwardly when the nozzle 20 is stored in a boot on the fuel
dispenser 10. Under this definition, the posterior side of the nozzle
20 is the side with the lever whose actuation begins fuel flow,
as is well understood. Alternatively, the cavity 86 may be positioned
on a side or a posterior surface if needed or desired.
[0034] While two exemplary static charge sensors 60 are shown,
it should be appreciated that other static charge sensors may be
used in place of the exemplary static charge sensors 60 provided.
For example, the electrodes 62 and 76 could be replaced with a flat
surface pickup.
[0035] For further information about how electronic components
within a nozzle 20 may be connected to electronic components in
a fuel dispenser 10, the interested reader is referred to U.S. Pat.
Nos. 5,267,592 and 5,365,984, both of which are hereby incorporated
by reference in their entireties. In particular, the details relating
to the wiring connections between the nozzle, the hose, and the
fuel dispenser may be of interest. Alternatively, if the complexity
of the wiring through the hose 18 is too troublesome, it is possible
that the electronics of the present invention may communicate wirelessly
from the nozzle 20 to the electronic components 24 within the fuel
dispenser 10 through a battery powered transmitter in the nozzle
20 and a wireless receiver in the fuel dispenser 10.
[0036] FIG. 5 illustrates an exemplary circuit diagram for the
static charge sensor 60. The electrode, such as the generally hook
shaped electrode 62, is connected to one or more clamp diodes 88,
and then connected in series to a high value resistor 90 before
being connected to a detector circuit 92 (FIG. 5). In a particularly
contemplated embodiment, two clamp diodes 88 are used in parallel,
clamping both positive and negative voltage as is well understood.
The clamp diode 88 is protected by a series resistor 93, which prevents
damage to the clamp diode 88 in the event of an accidental static
hit. The clamp diode 88 prevents an electric surge from damaging
down stream electronic components, such as the detector circuit
92. It should be appreciated that the generally hook shaped wire
electrode 62 is connected to the clamp diode 88 via electrically
conductive wire 70. Furthermore, the clamp diode 88, the high value
resistor 90 and the detector circuit 92 may be considered part of
the electronic components 24 positioned within the fuel dispenser
10. Alternatively, some or all of these elements may be positioned
in the nozzle 20, with the electrically conductive wire 70 extending
from the detector circuit 92 to the electronic components 24 of
the fuel dispenser 10, and particularly to the dispenser controller
26. In an exemplary embodiment, the high value resistor 90 and the
series resistor 93 are in the neighborhood of 20 k.OMEGA.. It should
be appreciated that other circuits are also possible for the static
charge sensor 60.
[0037] FIG. 6 illustrates a more detailed schematic of the detector
circuit 92 with the clamp diode 88 and high value resistor 90 eliminated.
The static charge sensor 60 provides a current along electrically
conductive wire 70 through the hose 18. Similarly, the wire mesh
64 couples to ground through the hose 18. The detector circuit 92
receives the current induced in the static charge sensor 60 by a
static charge, and passes the current through an amplifier 93 and
a resistive element 94 having a known resistive value. Thus, the
signal from the electrode becomes an amplified signal. The amplified
signal passes through the resistive element 94. A voltmeter (VM)
96 is connected in parallel to the resistive element 94 and provides
an output signal to the dispenser controller 26, which compares
the output signal to the predetermined threshold. Alternatively,
a computer may be incorporated into the voltmeter 96 and compare
the detected voltage to the predetermined voltage within the combined
structure. In an exemplary embodiment, if the voltmeter 96 outputs
a signal over a few millivolts, then the threshold of the present
invention has been exceeded, and safety measures are invoked as
explained in greater detail below. As yet another alternative, instead
of detecting a voltage, a current could be detected in an appropriate
manner. In the current sensing alternative, a lower impedance current
detector would be used in place of the high impedance voltage detector.
[0038] While FIGS. 5 and 6 show exemplary circuits for the implementation
of the static charge sensor 60 and detector circuit 92, it should
be appreciated that other circuitry may be used in place thereof
and the same function achieved. The precise details of the detector
circuit 92 and the connection between the static charge sensor 60
and the detector circuit 92 are not critical to the present invention.
[0039] While the previous discussion has focused on a static charge
sensor 60 positioned in a nozzle 20 of the fuel dispenser 10, FIG.
7 shows a number of alternate placements for the static charge sensor
60. Specifically, the fuel dispenser 10 of FIG. 7 shows that the
static charge sensors 60 may be positioned on the nozzle 20 as previously
illustrated, on the side 98 of the fuel dispenser 10 proximate an
edge 14, on the front 100 of the fuel dispenser 10 proximate an
edge 14, on the door 44, in the user interface 22, on the door 42,
or on the fuel dispenser canopy 16. While it is particularly contemplated
that the static charge sensors 60 may be positioned proximate edges
14, these placements are not strictly required, and the static charge
sensors 60 may be positioned where desired.
[0040] Furthermore, the static charge sensors 60 may be positioned
proximate a fuel dispenser 10, but not necessarily within the housing
12. For example, the static charge sensor 60 may be on a canopy
pillar 102, a canopy roof 104, a collision barrier 106, or other
item in the forecourt of the fueling environment. Additionally,
it is possible that the fuel dispenser 10 may have peripherals such
as an advertising placard placed above the fuel dispenser 10 or
the like. The static charge sensor 60 may be associated with such
peripherals if needed or desired.
[0041] The present invention also adds safety measures to the fueling
environment in the form of a fan. Such fans will help disperse hydrocarbon
vapors such that if a statically induced spark event occurs, there
are no hydrocarbon vapors proximate the spark to cause an explosion.
For example, as shown in FIG. 8, an upper fan 108 may be positioned
on the fuel dispenser canopy 16 of the fuel dispenser 10. Alternatively,
a face fan 110 may be built into the face of the fuel dispenser
10, such as in the user interface 22. Another option would be a
bottom fan 112, which points upward from a lower portion of the
fuel dispenser 10. As yet other options, the fans could be mounted
some distance removed from the fuel dispenser 10, such as a pillar
fan 114, mounted on the canopy pillar 102 or a canopy fan 116, mounted
on the canopy roof 104. It should be appreciated that fans may be
positioned in other locations as needed or desired.
[0042] As noted above, the present invention initially detects
whether a static charge is present and then activates one or more
safety devices to minimize the risk of explosion in the event of
a statically induced spark. In a first exemplary embodiment, illustrated
schematically in FIG. 9, the dispenser controller 26 receives the
voltage from the voltmeter 96 of the static charge sensor 60, determines
if the voltage is greater than the predetermined threshold, and
activates one or more safety devices. Specifically, upon determining
that the static charge is above the predetermined threshold, the
dispenser controller 26 may, if fuel dispenser pump 36 is present,
turn off fuel dispenser pump 36. By preventing additional fuel from
reaching the fuel dispenser 10, the potential for creation of additional
hydrocarbon vapors proximate the fuel dispenser 10 is minimized.
[0043] Alternatively, if the fuel dispenser pump 36 is not present,
the dispenser controller 26 may instruct the submersible turbine
pump 40 to turn off. Again, by preventing additional fuel from reaching
the fuel dispenser 10, the potential for harm is reduced. As another
alternative, fuel control valve 32 may be closed. This effectively
stops additional fuel from reaching the fuel handling components
34 of the fuel dispenser 10, reducing the potential for explosion.
Alternatively, the dispenser controller 26 may turn on one or more
fans, such as fans 108, 110, 112. When a fan is activated, it causes
air to circulate, which in turn disperses the hydrocarbon vapors,
such that the risk of harm is reduced.
[0044] As yet another alternative, the dispenser controller 26
may cause an alarm 118 to be generated. The alarm 118 may be audible
or visual, and is typically implemented through the user interface
22, which includes audible and visual components, as is well understood.
As still another alternative, the dispenser controller 26 may inform
the site controller 46 of the static charge and the site controller
46 (SC) may react accordingly. It should be appreciated that one
or more of these safety devices may be activated concurrently or
sequentially. There is no strict requirement that only one safety
device be present.
[0045] In a second exemplary embodiment, illustrated schematically
in FIG. 10, the static charge sensor 60 reports directly to a site
communicator (such as the site controller 46 or the tank monitor
50). The static charge sensor 60 may report through the dispenser
controller 26 as described above, or may report directly to the
site communicator. In either event, the site communicator may then
determine if the reported static charge exceeds the predetermined
threshold, and if that determination is positive, activate one or
more safety devices to implement a safety plan. Particularly contemplated
safety plans include turning off the fuel control valve 32, turning
off the fuel dispenser pump 36 if it is present, turning off the
submersible turbine pump 40, reporting the condition to an off site
location 54, turning on one or more fans (108, 110, 112, 114, or
116), or activating a site operator alarm 120 such that the site
operator is alerted to the static charge condition. The site operator
alarm 120 could be audible or visual as needed or desired. This
arrangement is potentially better suited for those instances where
the static charge sensor 60 and/or the safety device is removed
from the fuel dispenser 10 because this eliminates the need for
an electrical connection to the fuel dispenser 10. That is, if the
static charge sensor 60 was positioned on the canopy pillar 102
as was the pillar fan 114, then there is no need to route wires
through the fuel dispenser 10 to enable, use of the pillar fan 114
and the static charge sensor 60. Instead, this embodiment allows
the static charge sensor 60 and the pillar fan 114 to be communicatively
coupled to the site communicator and controlled by the site communicator.
[0046] As yet another embodiment, the present invention may also
have the static charge sensor 60 report directly to the off site
location 54 (as shown by the dotted line in FIG. 10), and the off
site location 54 may activate one or more safety devices.
[0047] A flow chart exemplifying the methodology of the present
invention is illustrated in FIG. 11. Specifically, the present invention
initially installs static charge sensors 60 (block 150). This installation
may be accomplished through retrofitting existing fueling environments
or installing new fuel dispensers 10 with static charge sensors
60 integrated thereinto. The present invention also requires the
presence of the safety devices, and thus, the safety devices are
installed (block 152). In some instances, the safety device is,
present, but the control thereover is established in accordance
with the present invention. For example, fuel control valves 32
are already present. However, the ability of the dispenser controller
26 or the site controller 46 to turn of the fuel control valve 32
in response to a static charge condition is implemented. Likewise,
the fans 108, 110, 112, 114 and 116 or new safety devices may be
installed in this step. It should be appreciated that the safety
devices may be retrofit into existing fueling environments or integrated
into new fuel dispensers 10 as needed or desired.
[0048] Having installed the static charge sensors 60 and the safety
devices, the deployed static charge sensors 60 monitor static charge
levels and report output relating thereto to a decision maker (block
154). As alluded to above, the decision maker could be the dispenser
controller 26, the site communicator, the off site location 54,
or even the static charge sensor 60 as needed or desired. When the
decision maker determines that the sensed static charge is above
the predetermined threshold, the decision maker then activates one
or more safety measures (block 156). As noted above, the activation
of the safety measure may be turning on a fan 108, closing the fuel
control valve 32, turning off the fuel dispenser pump 36, turning
off the submersible turbine pump 40, generating the alarm 118 or
the like. Likewise, more than one safety measure may be activated
as needed or desired. The purpose of the safety measure is to disperse
or reduce hydrocarbon vapors proximate the fuel dispenser 10 (block
158).
[0049] Once the decision maker has determined that the static charge
level sensed by the static charge sensors 60 is below the predetermined
threshold, the fueling environment operation returns to normal (block
160).
[0050] Other reasonable permutations of the present invention are
also contemplated. For example, the static charge sensors 60 may
detect excursions in either polarity. That is, either a positive
or a negative charge may be sensed with the appropriate detection
circuitry.
[0051] Those skilled in the art will recognize improvements and
modifications to the preferred embodiments of the present invention.
All such improvements and modifications are considered within the
scope of the concepts disclosed herein and the claims that follow.
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