Note: Descriptions are shown in the official language in which they were submitted.
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GAS BURNER TOOL FOR PURGING A GAS SUPPLY PIPE
BACKGROUND OF THE INVENTION
This invention relates to a gas burner tool for use in purging a gas
supply pipe.
In gas fitting, installation of new equipment or appliance generally
requires the appliance be attached to a gas supply pipe carrying gas from a
remote source such a main supply or a propane supply tank. In some cases the
gas supply pipe is relatively long and this is particularly a problem in supply of
propane where the tank is necessarily located at some distance from the main
building and the appliance.
After the installation is complete, it is necessary to commence
supply of gas through the pipe from the source to the installed appliance and toignite that gas when the combustible gas reaches the appliance.
Generally the combustible gas is preceded in the supply pipe with a
non-combustible gas including air, various solvents from the piping, desicants to
remove water vapor from the pipe and the like. Often these non-combustible
gases include noxious smelling agents of the type added to combustible gas to
provide a characteristic smell.
Up until now, gas fitters have in many cases simply turned on the
gas supply so that the non-combustible gas is purged through the pipe at the
installed equipment or to the outside and have waited a sufficient period of time
for the non-combustible gas to escape, after which the combustible gas is
ignited .
This leads to two problems. Firstly the non-combustible gas is
released into the atmosphere which can release noxious materials and foul
smelling gases. Secondly, if the gas fitter waits too long, the combustible gases
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can be released into the building where the danger of explosion either
immediately at ignition of the installed appliance or subsequently when the
conditions have reached the optimum for explosion to occur. This is particularlya problem with propane which is heavier than air and therefore settles at floor
5 level so that it is less detectable. The release of the non-combustible gases can
also mask the characteristic odour added to the combustible gas.
It is known to flare off purged gases to the outdoors. For example,
the Canadian regulations for gas fitting CAN/CGA-B149.2-M91 define on page
14 a "purge burner" as "a burner equipped with a constant ignition source and a
10 flame arrestor intended to burn the escaping (discharged) propane during purging
operations". The same document refers to purging to the outdoors on page 63
and in 5.24.7 states that "when flaring is used to purge a piping or tubing
system an approved purge burner is to be used". However no apparatus for
assisting a fitter in purging a pipe primarily in an indoors situation is known to
15 exist.
A search has revealed US Patents 4779608, 4276017 and
4419160, but these do not provide devices suitable for this purpose.
SUMMARY OF THE INVENTION
It is one object of the present invention, therefore, to provide a tool
20 for use in purging a gas pipe.
According to the first aspect of the invention there is provided a
tool for use in gas fitting comprising a hose line having a coupling at one end for
attachment to a gas pipe, a first burner nozzle attached to an opposed end of
the hose line for generating a stream of gas from the gas pipe, a venturi for
25 drawing air into the stream of gas, and means for burning the stream of gas
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comprising a second burner nozzle for directing a burning gas into the stream
and means for attaching the second burner nozzle to a supply of gas separate
from said gas pipe.
Preferably the second burner nozzle is arranged to direct the
5 burning gas at an angle across the stream.
Preferably the tool includes a supply of gas comprising a portable
tank containing propane, the propane supply and the second burner nozzle being
arranged such that the burning gas from the second nozzle has sufficient heat tocause combustion of at least some non-combustible products emerging from the
10 first burner nozzle during purging of the gas supply line and to cause ignition of
combustible gas emerging from the first burner nozzle when purging of the gas
supply line is complete.
Preferably the tool includes a supply of gas comprising a portable
tank wherein the tool includes a portable frame having a first receptacle on the15 frame for receiving and supporting the portable tank and a second receptacle for
locating the second burner nozzle.
Preferably the first receptacle comprises a cylindrical sleeve.
Preferably the second receptacle for the second burner nozzle
comprises an upstanding support arm carried on the first receptacle for the tank20 and defining a notch into which the second burner nozzle located.
Preferably the first burner nozzle stands generally upwardly.
Preferably the tool includes a base frame for resting upon a support
surface and carrying the first burner nozzle.
Preferably the tool includes a protective grid surrounding the first
25 burner nozzle.
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Preferably the first burner nozzle includes a flame arrestor.
Preferably the tool includes a hanger for receiving and supporting
the hose line in stored condition.
Preferably the tool includes a base frame and a plurality of
receptacles each for receiving a respective one of the plurality of gas fittings by
which the coupling of the hose line can be attached to a number of different
types of gas pipe outlets.
According to a second aspect of the invention there is provided a
tool for use in gas fitting comprising a frame with a base for resting upon a
10 support surface, a hose line having a coupling at one end for attachment to agas pipe to be purged, a first burner nozzle mounted on the frame so as to standgenerally upwardly therefrom, the first burner nozzle being connected to an
opposed end of the hose line for generating a stream of gas from the gas pipe, aventuri mounted on the first burner nozzle for drawing air into the stream of gas,
15 and a receptacle mounted on the base frame for receiving and supporting a gastorch having a second burner nozzle and a gas supply tank attached thereto, the
receptacle being arranged to receive and mount the torch such that the second
burner nozzle of the torch directs a stream of burning gas into the stream from
the first burner nozzle.
According to a third aspect of the invention there is provided a
method for purging a gas supply pipe comprising attaching a coupling on the gas
supply pipe to one end of a hose line, providing a burner nozzle at an opposed
end of the hose line for generating a stream of gas purging from the gas supply
pipe, providing a stream of burning gas from a supply separate from the gas
25 supply pipe, directing the stream of burning gas into the stream of gas from the
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gas supply pipe, the burning gas having sufficient heat to cause combustion of
at least some non-combustible products in the gas supply line, and continuing topurg gas from the gas supply pipe until combustible gas emerges from the gas
supply pipe and is ignited by the stream of burning gas.
One embodiment of the invention will now be described in
conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of a tool according to the present
invention.
Figure 2 is a top plan view of the tool of Figure 1.
In the drawings like characters of reference indicate corresponding
parts in the different figures.
DETAILED DESCRIPTION
The tool is generally indicated at 10 for use in installation of an
15 appliance at 11 to a gas supply 12 including an installed gas supply pipe 13 for
carrying gas from the supply to the appliance.
The gas supply pipe 13 includes a drop leg 14 adjacent the
appliance of a conventional nature necessary for extracting contaminants from
the gas line.
The tool 10 comprises a flat base plate 15 which is generally
rectangular in shape with curved corners for aesthetic appearance. The base
plate 15 carries an upstanding cylindrical receptacle 16 which is attached at its
bottom end to the plate and has an open mouth 17 at its upper end. A handle
18 is attached to one side of the receptacle 16 so that the tool can be manually25 grasped and carried from place to place. The handle is located in a position so
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that the base plate 15 can be carried in horizontal orientation with an underside
19 laid upon a support surface to hold the receptacle 16 vertical.
The receptacle 16 receives a conventional propane bottle 19 and is
dimensioned to receive an contain the bottle and hold that bottle vertical within
the receptacle. A spring clip 16A frictionally retains the bottle in the receptacle.
At an upper end of the bottle is provided a control valve 20 which allows release
of a gas from the bottle on actuation of a manually operable valve element 21.
On top of the valve 20 is mounted a burner nozzle 22 which then includes a firstportion extending vertically upwardly from the bottle and a second portion
10 inclined upwardly and to one side of the bottle. Such gas burner torches are of
course well known and readily available from all plumbing and similar stores foruse in generating a stream of burning gas as indicated at 23 for various
purposes .
The tool 10 further includes a second receptacle 25 in the form of
15 an upstanding plate 26 attached to one side of the cylindrical receptacle 16 and
standing upwardly therefrom. The plate 26 includes a notch 27 defined between
a pair of upstanding fingers so the notch receives an undersurface of the nozzle22 to locate that nozzle in between the fingers and directing the nozzle to a
required angular orientation around the axis of the cylindrical receptacle 16.
The tool further includes a gas burner nozzle 30 attached to a
vertical gas pipe 31 carried on an elbow 32. The elbow 32 is fixed to the base
plate 15 so as to hold the pipe 31 vertical and to locate the nozzle 30 in a
vertical orientation to form a vertical stream 33 of gas exiting from the nozzle30. The nozzle 30 has a relatively small orifice 34 so that the gas exiting from25 the nozzle forms a vertical stream which is relatively narrow and remains as a
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consistent stream with little diffusion to a height of the stream above the
burning gas stream 23. Behind the nozzle 30 between the nozzle and the pipe
31 is provided a flame arrestor 30A formed of a wire mesh material 30B or
similar known arrangement to prevent any flame at the nozzle from traveling
5 back through the pipe to the supply.
Around the nozzle 30 is mounted a sleeve 36 having an inlet
opening 37 around the nozzle 30 so the sleeve and the nozzle act as a venturi
drawing air into the opening 37 and mixing that air as indicated generally at 38with the stream 33.
The elbow 32 is attached to a horizontal pipe section 40 which
includes a coupling 41 at its outer end attached to a flexible hose 42. An
opposed end of the flexible hose 42 carries a coupling 43 for attachment to the
drop leg 14.
The particular details of the couplings are not shown as these are
15 well known to one skilled in the art and can vary in dependence upon the
particular gas fittings selected for the various elements.
Around the sleeve 36 is mounted a guard screen 45 formed of a
suitable perforated screen material. The screen material extends from the base
plate 15 up to a top edge 45A at a height above the nozzle 22 so as to confine
20 the flame for preventing communication of significant heat to any surounding
combustible materials. The guard screen is U shaped in plan and extends from a
hinge 46 at one side of the cylindrical receptacle 16 around the sleeve 36 and
the nozzle 30 to a latch 47 on an opposed side of the cylindrical receptacle 16.The screen or grid 45 thus prevents the user from inadvertently contacting the
25 sleeve during operation of the tool. A hanger 50 in the from of a J-shaped loop
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is attached to the screen 45 and provides a hook for receiving loops of the hose42 looped thereover.
On the base plate 15 is mounted a plurality of receptacles 55 each
for receiving a certain one a plurality of gas fittings suitable for attachment to
the coupling 43 also the gas fittings are selected so that they provide an arrayof types of fittings which are suitable for accommodating various different types
of couplings in the gas supply and appliance system. Thus the coupling 43 can
be attached using one or other of the selected fittings to the drop leg or to a
gauge port on the appliance itself. Similar gauge ports are also provided in other
10 areas of the supply and appliance system so that the gas fitter can attach the
fitting to a number of different locations through the system as required to purg
gas at different locations in the system.
The tool can of course be supplied without the conventionally
available propane torch and burner.
In operation the gas fitter when the appliance is installed attaches
the coupling 43 to a suitable location at or adjacent the appliance. When the
connection is complete, the gas from the torch is ignited thus generating the
burning stream 23. The nozzle 22 is located so that it directs the burning
stream across the top of the grid or screen 45 at an angle upwardly.
With the gas stream 23 ignited and generating a significant heat
generally greater than 1200~F and preferably of the order of 1500~F, the supply
is opened using the conventionally available valves so that gases in the supply
line 13 are purged through the hose 42 and into the burner nozzle 30.
It can be appreciated that initially the gases purged are non-
25 combustible including air, various solvents, and other materials which are formed
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into the stream 33 and mixed with air to form a narrow stream exiting from the
top of the sleeve 36 and from the top of the screen 45 and intersecting with theburning stream 23.
While the non-combustible products in the line 13 are ejected
5 through the nozzle 30, these products do not directly ignite, particularly because
the mixture with air is not at the right proportions for combustion, but are
consumed in the heated jet 23 to burn off hydrocarbons and noxious gases to
remove the foul odor and to prevent the release of such noxious material into
the atmosphere.
As soon as the combustible gas fills the pipe line 13 and passes into
the hose 42, the combustible gas reaches the nozzle 30 and mixes with the air
thus becoming combustible in the stream 33 so that the heated stream 23
ignites the stream 33 and demonstrates by that ignition to the fitter the fact that
the combustible gas has reached the coupling 43 and thus filled the line 13.
Once the ignition of the gas has occurred and had remained steady
it is clear that all of the non-combustible gases have been extracted and all ofthe combustible gases which have been emitted from the supply line have been
burnt thus preventing any remaining combustible gases from escaping into the
area surrounding the appliance. Because of the presence of the venturi which
20 adds air into the gas stream, any combustible gas which reaches the nozzle inadmixture with air in the pipe will not ignite as the mixture will be too lean for
ignition. The combustible gases will however burn off in the flame from the
torch. Only when the combustible gas reaches the nozzle substantially in pure
form will it ignite thus giving a visual indication of the arrival of the pure supply
25 gas.
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The supply is then closed off, the torch is turned off, the coupling
43 removed from its location and the location is capped to prevent further
escape of gases. In this situation, therefore, it is known that the supply line 13
is filled with the combustible gas and that combustible gas is carried to the
5 location immediately adjacent or at the appliance. The appliance can thereforebe ignited substantially immediately since the gas is at the appliance and readyfor ignition.
The tool therefore prevents of inhibits the possibility of escape of
combustible gases, provides a visual indication of the arrival of the pure supply
10 gas in combustible form and also burns off the non-combustible products carried
in the supply line to prevent the escape of noxious materials.
If required, a known blow-back combustion arrestor (not shown)
can be added into the lie upstream of the nozzle.
Since various modifications can be made in my invention as herein
15 above described, and many apparently widely different embodiments of same
made within the spirit and scope of the claims without departing from such spirit
and scope, it is intended that all matter contained in the accompanying
specification shall be interpreted as illustrative only and not in a limiting sense.
