Improvements in Blow Torch Burners.
Year: 1897

page_text: Date of Application, 14th Aug., 1897-Accepted, 6th Nov.,
1897
Improvements in Blow Torch Burners.
I, JOHN CURTIS DUPEE of Warren Avenue, Chicago, Illinois, U.S.A., Machinist
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
This invention has for object to provide an improved burner for plumbers'
braziers' and other furnaces in which hydro carbon oils are employed, the con-
struction of the burner being such that a blow torch or force blast having a
heating, as distinguished from an illuminating flame, may be obtained from
hydrocarbon oils of low gravity such as kerosine or crude petroleum. To this
end the contour of the burner is so constructed and adjusted with reference to the
retort that in its effort to escape from the mouth of the burner, the flame when
forced by a strong blast or air pressure is choked sufficiently to produce eddies
and cause a back flow to impinge upon and heat the retort.
In the accompanying drawing Fig. 1 is a side elevation of a plumbers' furnace
embodying the features of the invention.
Fig. 2 is an enlarged central sectional view of a modified form of burner,
arranged horizontally, and Fig. 3 a detail view taken upon the line 3-3 of Fig. 2
viewed in the direction of the arrow.
In the drawing a is the usual tank for the storage of hydro carbon oil, connected
with which is any well known form of air pump asb for the purpose of compressing
air therein in order to force oil to the burner.
Above the tank and sustained upon posts c attached to the tank is secured the
ordinary short chimney top d within which may be placed the melting pot.
Connected with the tank a is a tube e which, in the form of furnace shewn in
Fig. 1 is extended upwardly and thence horizontally so as to connect with and
form a support for a vertical burner. The service pipe e is tapped into a retort g,
which consists of a hollow annular ring integral with which is a tube h having
a tube i tapped therein. A nipple j is tapped into the part i the opening in
which is adapted to be closed by means of the usual needle valve k. The opening
in the nipple is directed towards the centre of the opening formed by the retort g.
Extending downwardly or backwardly as the case may be, according as the
burner is arranged vertically or horizontally, are flanges 1 which are integral
with the retort and are provided with slots m therein. Upon the opposite side
of the retort is formed an annular flange q (Fig. 2) into which is tapped or other-
wise secured, a hollow pear shaped extension the interior of which forms the
mixing and combustion chamber. The diameter of the interior of that portion
of the part n which is tapped into the ring is greater than the diameter of the
interior of the ring formed by the retort, and is also greater than that of the
eduction opening or outer end of the extension, but is very much smaller than
that of the intermediate portion which forms a bulge o as shewn. In other words

page_text: the base of the pear shaped shell is placed next to the retort. In the bulge o is
formed a series of openings p (Figs. 2 and 3) which are so arranged with reference
to the retort g that a flame passing through said openings may impinge directly
upon the retort.
The usual drip cup r serves to heat the burner. A shield or
hood is preferably provided to protect the jet from side drafts.
The device operates as follows:
The oil, by reason of the pressure of air in the tank, is forced upwardly through the
tube e from whence it passes through the annular retort where it is vaporized.
The vapour then passes through the tubes h, i, and escapes from the nipple j in
the form of a jet which is directed towards the centre of the opening formed
by the annular retort. The air is admitted freely from the rear and through
the slots m.
The jet ignites shortly before it reaches the annular retort and
this serves to partially heat the latter. As a considerable air pressure is employed
in the tank the impingement of the flame upon the retort causes it to enlarge
and fill the combustion chamber, and as the diameter of the chamber is suddenly
restricted from the bulge o and tapered as shewn, eddies are formed in the flame
as indicated by the arrows; and while the main flame is directed forward and
outward from the eduction end of the tapered nozzle, portions thereof are directed
backwardly and forced out through the openings in the form of jets which
impinge upon and serve to heat the outside of the retort. A further advantage
is derived from the formation of eddies in the combustion chamber, namely, the
complete commingling of air and gas at the point of combustion where the
temperature is sufficiently high to render the combustion complete.
Heretofore is has been found wholly impracticable to utilize low gravity oils for
burners known as blow torch or pressure burners. Any confinement by the use
of baffle plates or similar devices adapted to produce a back flow of the flame not
only eliminates the torch feature thereof, but so softens it that it fails to vaporize
the heavy oil; thereby defeating the end desired, although such a burner may
be entirely effectual in burning high gravity oils.
I have found in actual practice that by means of my improved burner, supple-
mented by an air pressure in the oil reservoir of from about twenty to one hundred
pounds per square inch, a low gravity oil may be used as readily as can naptha
with the ordinary burner employed therewith. The combustion is complete and
the body of the flame is not materially lessened by the divergence of the jet there-
from required to heat the retort, which jets can only be produced by means of a
forced blast as described. Moreover, the retort does not become overheated and
the tendency of the oil to carbonize therein is obviated.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
ciaim is:
1. The combination with an oil reservoir and means for forcing a jet of oil
therefrom under pressure, of a retort, means for projecting a vaporized jet from
said retort through an opening extending through said retort into a combustion
chamber, and a combustion chamber adjacent to said retort, said combustion chamber
having a restricted opening at its outer end, an enlargement in the body thereof 4
next to said retort and a series of openings in its walls in operative proximity
to said retort, whereby a portion of the main flame from the combustion chamber
may be reversed as a result of the eddies formed in said enlargement by the forced
action of the flame and caused to impinge upon the retort, substantially as
described and shewn.
5
2. As an improvement in blow torch burners, the combination with a retort
and means for projecting a vaporized jet therefrom through an opening extending
through said retort, of a pear shaped projection or shell, the interior of which
is adapted to form a combustion chamber, the base of said shell being attached
to said retort and having an interior diameter larger than that of the opening 5
through said retort, an eduction opening of smaller diameter than that through

page_text: said retort and an intermediate enlargement having a series of openings therein
in operative proximity to said retort, substantially as described and shewn.
Dated this 14th day of August 1897.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C., Agent for the Applicant.