Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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~PP~RAT~S AND M~T~OD TO AnD KINETIC RNERGY
TO A LOW PRESSURE WASTE GAS FLARE BUR~ER
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Background of the Invention
This invention relates to the art of flaring
low pressure hydrocarbon gases, smokelessly.
It is well known in the art that flaring of
low pressure hydrocarbon gases having a molecular weight
ratio of hydrogen to carbon less than 0.30 tends to produce
smoke as a result of incomplete combustiorl and the formation
of free carbon particles. The release of free carbon into
the atmosphere creates a dark smoke plume which is unsightly
and a matter of poor ecological practice. Various methods
have been devised for coping with smoke generation. One
metho~1 involves the introduction of a smoke suppressant,
typically steam or water to the combustion zone. The water,
in vapor phase, reacts with the hydrocarbon by familar and
well known endothermal reactions. In some instances, the
introduction of this suppressant also introduces air to
assist in the complete combustion of the burning ~ases.
Another method relates to the use of powered air for turbu-
lent mixin~ of air with the hydrocarbon gas for more complete
smokeless combustion.
There are instances in certain refineries, or
process plants where neither steam or water or air powered
turbulent mixing are available to smokelessly burn or
flare low pressure hydrocarbon gases that are created as a
part of the plant. The flaring of such gases is the only
economical manner in which to han~dle these gases which
must be removed from the system since they are not capable
o~ being utilized elsewhere.
Wind is another problem with burning low pressure
hydrocarbons above an elevated stack. If there is insuffi-
cient pressure to cause the flame to 'stand-up' the flames
will 'lick' the side of the stack causing its destruction,
besides the constant problem of maintaining iqnition.
Standinq the tlames upward is preferred.
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SUMM~RY OF THE INVENTION
It is a primary object of this invention to provide an
apparatus which will impart additional energy to a low pressure
waste gas which is to be flared since the gas, being at re-
latively low pressure, cannot of its own energy inspirate the
necessary combustion air for complete smokeless combustion.
It is a further object of the invention to provide
elevated flare stack burning of low pressure waste gas, wherein
the burning flame is caused to 'stand-up' or maintain an
essentially vertical position above the stack.
It is a further ob-ject of -this invention to achieve
economy in the utilization of both a ]ow pressure gas which is
to be burned in a flare structure by the use of the energy of
an available high pressure gas to provide the required turbulent
air-gas mixture for complete smokeless combustion.
Another object of the invention is to provide a method
of burning low pressure waste gases by the induction of
additional kinetic energy thereto.
According to the invention there is provided flare
apparatus for inducing kinetic energy to low pressure waste
gas which is to be burned substantially smokelessly, comprising:
an array of burners, each of said burners defined by a tip and
a central, internally unobs-tructed, conduit which terminates
at an axial discharge opening at said tip; means to supply said
low pressure waste gas to said conduit for axial and linear
discharge above said tip; a manifold surrounding said conduit
and forming an annular chamber thereabout which maniEold in-
cludes, adjacent said tip, a plurality of arms which are in
communica-tion with said annular chamher and radially directed
outwardly oE said annular chamber, the top oE said arms being
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along or below a plane formed across the top of sai.d tip, at
least one opening formed in the top of a-t least one oE said
arms, the axis of each opening being directed inwardly and
primarily toward the direction along said axial discharge of
said low pressure gas above the tip; and means to supply a
high pressure fluid from said manifold to the upstream side of
each said opening in said arms.
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Brief Description of the Drawings
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Other objects and advantages of the invention and
a better understanding oE the principles and details of the
invention will be evident in the follc)wing description taken
in conjunction with the appended dra~ings in which:
FIGURE 1 is a top elevational view of the burner
of this invention.
FIGURE 2 is a sectional view taken along line 2-2
of FIGURE 1.
FIGURE 3 is a top elevational view of a conventional
flare stack which incorporates the burners of this invention
about its tip.
FIGURE 4 is a sectional view taken along line
4-4 of FIGURE 3.
.FIGURE 5 is a schematic view of an embodiment of
the invention showing a sequential flo~.~ of waste gases
from a low pressure condition to a high pressure condition
utilizing the apparatus of this invention to in-line burners
as used in a qround leveI flare burning system.
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Description of the Preferred Embodiment
Before explaining the present invention in detail,
it is to be understood that the invention is not limited
in its application to the details of construction and
arrangement of parts illustrated in the accompanying drawings,
since the invention is capable of other embodiments and of
being practised or carried out in a variety o~ ways. Also
it is to be understood that the phraseology or terminology
employed herein is for the purpose for description and not
limitationO
Referring to FIGURES 1 and 2 the numeral 10
generally indicates the flare apparatus of this invention.
The low pressure gas conduit 12 extends to a tip 14.
Surrounding the conduit is a coaxial manifold 16 and a
plurality of outwardly extending arms 20 that are in communi-
cation with the manifold 16. In each of the arms are one or
more openings 22, of size and oriented to the horizontal or
tip surface 19 so as to not only impart kinetic energy to
- the low pressure gas flowing upwardly in conduit 12 but also
main~ain t~e burning above tip 14 in a stand-up condition
substantially unafEected by wind conditions. Preferrably, an
angle A of at least 45a and openings 22 of size relative to
the high pressure gas to create sonic velocity therefrom.
FIGURES 3 and 4 indicate another embodiment of the
use of the apparatus of this invention wherein like numerals
are used for like parts as shown in FIG~RES 1 and 2~ In
this embodiment a central emergency flare stack 30 is
provided for venting large quantities of waste gas or high
pressure waste gas, whichever the case may be. Surrounding
the tip of waste flare conduit 30 are one or more flare
burner apparatus 10 extending circumferentially around the
stack. Supply manifold 32 for the low pressure waste gas
and 34 for the high pressure fluids are provided. This
embodiment provides flexibility to plants where low pressure
and high pressure waste gases are to be Elared.
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The embodiment of FIGURE 5 represents a flow
se~uential system for waste gases which may vary at low flow
or pressure rates to an extreme high flow or pressure rate.
I)uring normally low pressure or low flow conditions waste
gas enters via conduit 50 and 52 to olle or more burners lOa
via conduit 12. Likewise, high pressure gas will enter via
conduit 60 through 62 into the manifold system 16 surrounding
the low pressure conduit I2 as best shown in FIGURE 2. In
the event the flow or pressure of the inlet waste gas via 50
should increase a second set of burners lOb will come into
use. This occurs by sensing the pressure or flow condition
in waste gas inlet 50 which will then operate valve 70
controlling the high pressure fluid and valve 72 to the low
pressure gas which will allow for passage through respective
conduits 63 and 64 and 54 and 55. Further increase in
flow or pressure of the waste gas via conduit 50 additional
burner systems lOc, lOd, etc. may be utilized or an emergency
~lare which can handle larger quantities of gas may be
provided by flow through conduit 56 and thence 58. The flow
being controlledc by valve 74 and/or flow control through
pipe 76 into a water seal 78, the outlet 80 of which will
enter conduit 58 to an emergency flare stack, not shown.
The hiqh pressure fluids useful in the apparatus
of this invention includes gaseous or vaporous smoke suppres-
sants, such as steam or air, inert gases or combustible highpressure gases.
