U.S. patent application number 14/946926 was filed with the patent office on 2016-03-17 for dispenser for compressed natural gas (cng) filling station.
The applicant listed for this patent is Wayne Fueling Systems LLC. Invention is credited to Randy A. Moses, Kent W. Robinson.
Application Number | 20160076702 14/946926 |
Document ID | / |
Family ID | 50680503 |
Filed Date | 2016-03-17 |
United States Patent
Application |
20160076702 |
Kind Code |
A1 |
Moses; Randy A. ; et
al. |
March 17, 2016 |
Dispenser for Compressed Natural Gas (CNG) Filling Station
Abstract
A fueling station dispenser for distributing a combustible gas
that is lighter than air, and that includes electrical and gas
handling sections in the same frame. A vapor barrier in the cabinet
blocks fugitive gas that may be present in the gas handling section
from entering the electrical section. According to most applicable
codes, by isolating combustible gas from the electrical section
gives it a Class I, Division 2 designation. Which eliminates the
need to seal or air purge the electronics section as this
designation allows for electronics that under normal intended
operating conditions do not generate an arc with sufficient energy
to initiate combustion.
Inventors: |
Moses; Randy A.; (Palm,
PA) ; Robinson; Kent W.; (Quakertown, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wayne Fueling Systems LLC |
Austin |
TX |
US |
|
|
Family ID: |
50680503 |
Appl. No.: |
14/946926 |
Filed: |
November 20, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13939820 |
Jul 11, 2013 |
9222407 |
|
|
14946926 |
|
|
|
|
Current U.S.
Class: |
137/343 |
Current CPC
Class: |
F17C 2223/0123 20130101;
F17C 2270/05 20130101; F02B 43/00 20130101; F17C 2205/037 20130101;
Y02T 10/32 20130101; F17C 2260/04 20130101; Y02T 10/30 20130101;
F17C 2260/037 20130101; F17C 2205/0326 20130101; F17C 2265/063
20130101; F17C 2221/035 20130101; F17C 2265/065 20130101; F17C
2250/043 20130101; F17C 2250/032 20130101; F17C 5/06 20130101; F17C
2205/0107 20130101; F17C 2225/01 20130101; Y10T 137/6851 20150401;
F17C 2205/0176 20130101; F17C 2225/0123 20130101; F17C 2270/0165
20130101; F17C 2260/042 20130101 |
International
Class: |
F17C 5/06 20060101
F17C005/06 |
Claims
1. A dispenser for handling compressed gas comprising: a frame; a
gas handling section in the frame; an electronics section in the
frame; and a vapor barrier in the frame, so that when fugitive gas
is in the gas handling section, the fugitive gas is blocked from
flowing into the electronics section by the vapor barrier.
2. The dispenser of claim 1, wherein the vapor barrier comprises a
bulkhead in the frame that defines an upper terminal end of the gas
handling section.
3. The dispenser of claim 1, wherein the vapor barrier comprises a
bulkhead disposed in the frame above the gas handling section.
4. The dispenser of claim 1, wherein the vapor barrier comprises a
housing in the electronics section and in which electronics are
disposed.
5. The dispenser of claim 2, further comprising an electrical
conduit extending between the electronics section and the gas
handling section and through the bulkhead.
6. The dispenser of claim 1, wherein the gas comprises compressed
natural gas.
7. The dispenser of claim 1, further comprising side columns in the
frame that extend adjacent the gas handling section and to above
the electronics section, an opening in a sidewall of the gas
handling section, and a vent in a sidewall of each of the side
columns, so that fugitive gas in the gas handling section can flow
through the opening, along the side columns, and through the vents
to outside of the frame and past the electronics section.
8. The dispenser of claim 1, wherein the gas handling section is
defined as a Class I, Division 1 area, and the electronics section
is defined as a Class I, Division 2 area.
9. A dispenser for use with a combustible gas comprising: a frame;
a gas handling section in the frame in communication with a supply
of combustible gas; and an electronics section in the frame in
signal communication with the gas handling section; a vapor barrier
in the cabinet that defines an obstacle to a free flow of fugitive
gas to within the electronics section; and a vent system in which
fugitive gas from the gas handling section selectively bypasses the
electronics section.
10. The dispenser of claim 9, wherein the vapor barrier comprises a
bulkhead mounted in the frame.
11. The dispenser of claim 10, wherein the bulkhead is in the gas
handling section.
12. The dispenser of claim 10, wherein the bulkhead is in the
electronics section.
13. The dispenser of claim 9, wherein the vapor barrier comprises a
housing in the electronics section, and wherein electronics are
disposed in the housing that only during unexpected conditions are
the electronics capable of producing an arc having sufficient
energy to initiate combustion.
14. The dispenser of claim 9, wherein the vent system comprises
vertical open spaces housed in side columns on lateral sides of the
frame, openings that extend through sidewalls of the gas handling
section and that intersect with the vertical open spaces, and vents
in the side columns on a side of the electronics section opposite
the gas handling section, and that define a communication path
between the vertical open spaces and ambient.
15. A dispenser for handling a combustible gas comprising: a
cabinet; a gas handling section in the cabinet that comprises a
line in communication with a source of combustible gas, and that is
in selective communication with a nozzle outside of the cabinet; an
electronics section in the cabinet; a first bulkhead in the gas
handling section that defines a first vapor barrier; a second
bulkhead in the electronics section that defines a second vapor
barrier; and a housing in the electronics section having electrical
hardware disposed therein and that defines a third vapor
barrier.
16. The dispenser of claim 15, having electrical hardware that can
produce an arc having sufficient energy to initiate a combustion
only during unexpected operation.
17. The dispenser of claim 15, further comprising an air gap
between the gas handling section and the housing and an air gap
between side wall of the cabinet and the housing.
18. The dispenser of claim 15, wherein the gas is lighter than air.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 13/939,820, filed Jul. 11, 2013, and entitled
"Dispenser for Compressed Natural Gas (CNG) Filling Station," which
claims priority to U.S. Provisional Application Ser. No.
61/725,366, filed Nov. 12, 2012, and entitled "Dispenser for
Compressed Natural Gas (CNG) Filling Station," each of which is
hereby incorporated by reference herein in its entirety.
FIELD OF INVENTION
[0002] The present disclosure relates in general to a device and
method for dispensing fuels lighter than air, such as compressed
natural gas (CNG). More specifically, the present disclosure
relates to a gas dispenser having gas handling components and
electronics in the same structure, and where the electronics are
mounted in a non-purged housing spaced away from the gas handling
components.
BACKGROUND OF THE INVENTION
[0003] Traditionally, vehicles have been fueled by one or more
distillates of fuel oil, such as gasoline or diesel. Since these
fuels have vapors that are heavier than air, the dispensers for
these fuels were designed with the electronics located above the
fuel-handling, hazardous area. This allowed the dispenser structure
to be broken into different hazardous area classifications allowing
electronics to be located in the structure with minimal safeguards
from the flammable vapors below. Recently, a growing number of
vehicles have been manufactured, or converted, to operate on
compressed natural gas (CNG), which is lighter than air, instead of
the heavier than air longer chain hydrocarbons. The availability,
low cost, and lower emissions of combusting natural gas over fuel
oil distillates have garnered interest in continuing to increase
the number of natural gas powered vehicles. Similar to typical
gasoline or diesel fueling dispensers, CNG fueling dispensers,
whose structure contains piping and valves for delivering gas to a
customer, have been designed using similar dispenser structures
with the electronics, which control the dispenser and payment
authorization terminals, above the gas handling components.
[0004] Standards for the safe handling of CNG have been published
by national code recommending bodies. Many states have adopted
these codes in their respective vehicle, transportation, and
building regulations. As CNG is lighter than air, unlike gasoline
or diesel vapors, CNG that may escape from the gas handling
components can rise; and thus present different hazardous zones for
a CNG dispenser as compared to a gasoline or diesel dispenser. As
such, standards for CNG dispensers reflect a different hazardous
zone rating as compared to gasoline or diesel dispensers in these
standards. For example, explosive vapors may sometimes concentrate
in spaces above a gas handling portion of a CNG dispenser having a
traditional gasoline or diesel dispenser design. By most standards,
the spaces normally having the explosive vapor concentration would
be deemed Class I, Division 1, thus prohibiting any device capable
of producing a spark. For example, applicable codes typically
designate Class I locations to be where a flammable gas or vapor
may be present in a sufficient amount to produce an explosion or
ignitable mixture. Class I locations are sometimes designated as
Division 1 when the flammable gas is likely to exist, such as in
quantities sufficient to produce an explosive or ignitable mixture
under normal operating conditions. Class I locations are sometimes
designated as Division 2 when the flammable gas is not normally
present in an explosive concentration, but accidentally exists.
Some CNG dispensers having traditional gasoline or diesel dispenser
structures address this change in hazardous rating by enclosing
electronics in an explosion-proof junction box, including an
Intrinsic Safe Barrier (ISB), or disposing electronics in an air
purged enclosure protected through pressurization. There are some
components used in payments terminals that either due to the need
of accessibility to the customer or because of the type of
component, cannot be adequately protected by an explosion-proof
junction box or an ISB. When this is true, these components are
normally protected by an air purge system. Correctly implemented,
an air purge system can change the area within the enclosure to a
non-hazardous, or unclassified area. Air purge systems can be
affected by ambient pressure variations and wind. An air purge
system also exposes the electronics to cold and/or moist air that
can affect the operation of the components as well as corrode or
damage them. It can also inject dirt into the system. The fans used
for the source of air for air purge systems must be positioned in a
location away from the hazardous area that is created by the
dispenser, which increases installation costs and complexity.
SUMMARY OF THE INVENTION
[0005] Disclosed herein are embodiments of a dispenser for handling
a combustible gas. In one embodiment the dispenser includes a
frame, an electrical section, and a gas handling section. Further
included in the frame is a vapor barrier that blocks fugitive gas
from entering into the electronics section. Example vapor barriers
include a bulkhead in the gas handling section, a bulkhead in the
electronics section, a housing for electronics in the electrical
section, and combinations thereof. Without the rating whereby an
explosive mixture of gas normally is in the electronics section,
electronics can be deployed that do not create an arc during their
normal operation with sufficient energy to initiate combustion.
Also optionally included is a vent system that includes side
columns for venting fugitive gas from the gas handling section to
ambient and that bypasses the electronics section.
BRIEF DESCRIPTION OF DRAWINGS
[0006] Some of the features and benefits of embodiments of the
present invention having been stated, others will become apparent
as the description proceeds when taken in conjunction with the
accompanying drawings, in which:
[0007] FIG. 1 is a schematic example of a dispenser for compressed
natural gas illustrating safety code classifications of surrounding
zones and in accordance with the present disclosure;
[0008] FIG. 2 is a partial sectional view of the dispenser of FIG.
1 in accordance with the present disclosure;
[0009] FIG. 3 is a perspective view of a partial cut-away view of
an example of a portion of the dispenser of FIG. 1 in accordance
with the present disclosure; and
[0010] While the invention will be described in connection with the
preferred embodiments, it will be understood that it is not
intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0011] A method and system of the present disclosure will now be
described more fully hereinafter with reference to the accompanying
drawings in which embodiments are shown. Embodiments of the method
and system of the present disclosure may be in many different forms
and should not be construed as limited to the illustrated
embodiments set forth herein; rather, these embodiments are
provided so that this disclosure will be thorough and complete, and
will fully convey its scope to those skilled in the art. Like
numbers refer to like elements throughout.
[0012] It is to be further understood that the scope of the present
disclosure is not limited to the exact details of construction,
operation, exact materials, or embodiments shown and described, as
modifications and equivalents will be apparent to one skilled in
the art. In the drawings and specification, there have been
disclosed illustrative embodiments and, although specific terms are
employed, they are used in a generic and descriptive sense only and
not for the purpose of limitation.
[0013] FIG. 1 schematically illustrates an example of a gas
dispenser 10 in which a gas handling section 12 and electronics
section 14 are housed in a frame 16. In the example of FIG. 1, the
CNG dispenser 10 may be located at a fueling station 11 that offers
retail or wholesale purchase of CNG. Optionally, the fueling
station 11 can be onsite at a facility where all fuel dispensed is
for use at or associated with the facility. Examples include fleet
fueling, farming operations, manufacturing locations, and
processing facilities. As will be described in more detail below,
the gas handling section 12 includes gas handling equipment for
controlling a flow of gas from storage, through the dispenser 10,
and to a container removeable from the fueling station 11. Also
described in more detail below is that the electronics section 14
contains electrical hardware and software for monitoring and
recording an amount of gas dispensed, and optionally for monitoring
and processing payment of gas purchased. Further in the example of
FIG. 1, the electronics section 14 is disposed in a headspace
portion 17 shown included within the frame 16. The headspace
portion 17 does not extend into the gas handling section 12. As
shown, the gas handling section 12 and the body of the frame 16 are
in a Class I, Division I zone or area per code. Example codes
include those created by the National Fire Protection Association
(such as NFPA 52), the National Electrical Code (such as NEC
.sctn..sctn.500), and provided by 29 CFR .sctn.1910.307. Further
illustrated is a zone 18 surrounding the dispenser 10, where most
applicable codes designate the zone 18 and the headspace portion 17
(including the electronics section 14) as Class I, Division 2;
meaning under normal operating conditions, combustible gas, or
other flammable substance would not be present in sufficient
quantity/concentration to introduce a risk of combustion. In some
examples, zone 18 extends at least 5 feet from the outer periphery
of the frame 16. Unlike the more restrictive Class I, Division 1
area, placing arc capable electronics in a Class I, Division 2 area
does not violate code, if under normal or expected operating
conditions the electronics do not produce an arc having sufficient
energy to initiate combustion.
[0014] In one example, a vapor barrier between the gas handling
section 12 and the electronics section 14 removes paths of fugitive
gas flow between these sections 12 and 14. As such, electronics
section 14 is not in a Class I, Division 1 zone as specified in the
code. Instead the electronics section 14 is designated as a Class
I, Division 2 zone per code. The less restrictive Class I, Division
2 zone definition expands the options of electronics that can be in
electronics section 14. For example, absent isolating gas handling
section 12, to comply with code, electronics in section 14 must be
protected by an explosion-proof housing, and ISB circuit, or an air
purge system. Instead, by isolating electronic section 14 in a
separate housing whose structure is independent from the gas
handling housing, code compliance for a Class I, Division 2 zone is
achieved without the use of explosion-proof enclosures, an ISB or
an air purge system.
[0015] FIG. 2 illustrates a front cut away view of an example of
the dispenser 10 of FIG. 1. Here a supply line 20 is shown in the
gas handling section 12 for transporting a flow of gas from a gas
supply 21 to a nozzle line 22 that attaches to an outer surface of
the dispenser 10. Examples of the gas include compressed gas,
compressed natural gas (CNG), any gas lighter than air, any
combustible gas, any combustible gas lighter than air, and
combinations thereof In an example, the nozzle line 22 has an
attachment at its free end for connection to a vehicle 23 for
refueling the vehicle 23. Although the vehicle 23 is illustrated as
an automobile, the dispenser 10 can supply any device or system
that uses fuel to operate. Optionally, the nozzle line 22 can be
used for filling a vessel in which CNG is stored. A valve 24 is
further shown in FIG. 2 for controlling the flow of fluid through
line 20. The valve 24 is shown having an actuator 25 selectively
driving the valve 24 to open and closed positions, and all
positions between open and closed. Further illustrated is that the
actuator 25 is in communication with a control box 26, which in an
example is a sealed container having electrical connections for
electrical leads in the gas handling section 12. Electrical
conduits 28, 30 are shown that extend from the control box 26 and
through a bulkhead 32 in the frame 16. In an example, the bulkhead
32 is generally sealed and forms a vapor barrier that blocks a free
flow of fugitive gas. In one embodiment, the bulkhead 32 defines a
border of the gas handling section 12. The outer periphery of the
bulkhead 32 is positioned against an inner surface of the frame 16
to define an interface 33. Alternate examples of the gas handling
section 12 include any embodiment for controlling, regulating, or
otherwise managing a flow of gas through the frame 16.
[0016] A housing 34 is illustrated in the frame 16 in a space that
is on a side of the bulkhead 32 opposite the gas handling section
12. In the example of FIG. 2, the housing 34 is generally
rectangular and mounts on a bulkhead 35 to "float" in the frame 16.
Like bulkhead 32, bulkhead 35 defines a vapor barrier that blocks a
free flow of fugitive gas, and whose structure may be the same or
similar to bulkhead 32. As shown, the outer periphery of the
housing 34 is set inward from the inner surface of the frame 16,
and spaced upward from the bulkhead 32. Alternate embodiments
include mounting housing 34 directly to inner surface of frame 16.
In an embodiment, housing 34 functions as a vapor barrier and
blocks a free flow of non-pressurized fugitive gas. In this
example, fugitive gas that may be present in the head space 17 is
blocked by the housing 34 from becoming in contact with electronics
in the housing 34. As such, by providing a vapor barrier between
the gas handling section 12 and the electronics section 14,
electronics capable of arcing, but that do not normally arc, can be
put in the electronics section 14 without violating applicable
codes. Examples exist wherein structure described herein functions
as a vapor barrier, and yet is not air tight. Machined flat washers
36 are shown around the conduits 28, 30 where they pass through
bores in bulkheads 32, 35. Fasteners 38 maintain the washers 36 in
place and against the upper and lower surfaces of the bulkheads 32,
35 to form metal to metal seals. Example printed circuit boards 40,
42 are illustrated in the housing 34 as well as an example power
supply 44. Conduits 28, 30 provide a protective housing for wires
46, 48 that connect to boards 40, 42 and that may be in
communication with components disposed in the gas handling section
12. A polymer (not shown), or other flowable material, may be set
inside conduits 28, 30 for protecting any wires or lines therein.
Seals (not shown) may be included in the intersections between
conduits 28, 30 for ensuring isolation between the electronics
section 14 and frame 16 and gas handling section 12. In an
alternate embodiment, conduits 28, 30 may mount on a lateral side
of housing 34 and may optionally intersect a sidewall of gas
handling section 12. An optional air gap 49 is shown formed between
the upper surface of bulkhead 32 and lower surface of housing 34,
and in which conduits 36, 38 are disposed.
[0017] In the example of FIG. 2, boards 40, 42 are powered by power
supply 44 and include circuitry and/or processors configured for
card reading functions, or other functions for handling a
transaction of CNG sales. Control of the valve 24 or safety
functions may also be performed by hardware or software embedded in
the boards 40, 42. Further, as the gas handling section 12 is
isolated from the housing 34, the boards 40, 42 in the electronics
section 14 can be designated for use in a Class I, Division 2 zone
rather than the more stringent Class I, Division 1 zone. In one
example, isolating the electronics section 14 in the housing 34
from the gas handling section 12 includes blocking any continuous
flow paths between sections 12, 14. An advantage of disposing the
electronics section 14 within the frame 16 and suspended proximate
to the gas handling section 12 and optionally separated from it by
gap 49 is that the dispenser 10 can maintain the appearance of a
traditional dispenser while still complying with applicable
regulations. An advantage of the present disclosure is that an air
tight seal or housing is not required for the electronics in the
electronics section 14 to achieve isolation.
[0018] Further illustrated in the example of FIG. 2 are vents 50
formed through side columns 52 that extend along opposing lateral
sides of the structure 10. Openings 53 are shown through a sidewall
of frame 16 adjacent the gas handling section 12 that provide
communication from inside gas handling section 12 into a vertically
extending space in each side columns 52. In the example of FIG. 2,
fugitive gas from the gas handling components (e.g. valve 24, line
20, fittings, etc.) in the gas handling section 12 can flow from
gas handling section 12, through the openings 53, and into the side
columns 52. As bulkhead 32 is a vapor barrier, it prevents direct
upward flow of the fugitive gas. The side columns 52 form an upward
flow path for any of these fugitive gases that may leak from the
gas handling section 12. The vents 50 provide communication from
the side columns 52 to the space ambient to the structure 10 which
is a location remote from and above the electronics section 14. As
such, the combination of the bulkhead 32, openings 53, side columns
52, and vents 50 further protect against fugitive gas from entering
into the electronics housing 34.
[0019] Shown in a perspective partially exploded view in FIG. 3, is
an embodiment of the frame 16 where the side columns 52 include
side walls 54, 55 that extend substantially the height of the frame
16 on opposing lateral sides. Elongate thin walled panels 56, 57
are respectively positioned over and set back from side walls 54,
55 to form the vertically extending space in each side column 52.
In the example of FIG. 3, vents 50 are louvered openings provided
proximate the upper terminal ends of panels 56, 57 and openings 53
are in side walls 54. 55 (shown in dashed outline in side wall 55)
below bulkhead 32. Rear wall 58 is on a rearward side of frame 16
and adjacent the gas handling section 12. Forward wall 59, shown
partially cut-away, is on a forward side of the frame 16 and
adjacent gas handling section 12. frame 16. Referring back to FIG.
2, bulkhead 32 is shown having a substantially planar mid-portion
62 oriented generally transverse to side walls 54, 55, 58, 59. The
outer periphery of the bulkhead 32 angles perpendicular to
mid-portion 62 to define side surfaces that contact respective side
walls 54, 55, 58, 59 along interface 33. Thus the bulkhead 32
extends across opposing inner surfaces of the frame 16. Referring
back to FIG. 3, lateral side walls and a lower wall of the housing
34 are shown mounted in frame 16, with the lateral side walls set
inward from side walls 54, 55 of cabinet 16 to form an air gap
between housing 34 and frame 16. Further illustrated in FIG. 3 are
bores 74, 76 through the lower wall of the housing 34 receiving the
conduits 28, 30 of FIG. 2.
[0020] Embodiments of the present invention described herein,
therefore, is well adapted to carry out the objects and attain the
ends and advantages mentioned, as well as others inherent therein.
While a presently preferred embodiment of the invention has been
given for purposes of disclosure, numerous changes exist in the
details of procedures for accomplishing the desired results. For
example, embodiments exist where compliance with applicable codes
is maintained by providing a single vapor barrier (one or more of
bulkheads 32, 35 or housing 34) between the gas handling and
electronic sections 12, 14. These and other similar modifications
will readily suggest themselves to those skilled in the art, and
are intended to be encompassed within the spirit of the present
invention disclosed herein and the scope of the appended
claims.
* * * * *