IMPROVEMENTS IN TUBULAR FLUES FOR STEAM BOILERS
Year: 1875

page_text: LETTERS PATENT to Peter Jensen, of 33, Chancery Lane, in the
County of Middlesex, Engineer, for the Invention of "IMPROVEMENTS
IN TUBULAR FLUES FOR STEAM BOILERS."-A communication from
abroad by Lewis Benjamin Halsey and Robert Hamilton Deaderick,
both of the City and State of New York, United States of
America.
:
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the
Office of the Commissioners of Patents, with his Petition, on the
17th November 1875.
I, PETER JENSEN, of 33, Chancery Lane, in the County of Middlesex,
Engineer, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN TUBULAR FLUES FOR STEAM BOILERS," (a communication to me
from abroad by Lewis Benjamin Halsey and Robert Hamilton
Deaderick, both of the City and State of New York, United States of
America,) to be as follows:-
In the tubular flues of steam boilers the gaseous products of com-
bustion pass directly and unobstructedly through such flues, and

page_text: consequently the greatest heat is in the centre of the flue, and the
motion is more rapid at and near the centre than it is immediately
contiguous to the surface of the flue tube, this is especially the case
where the flue becomes roughened by a deposit of ashes or soot.
The present Invention is for directing the heated gases into more
intimate contact with the tubes, checking the speed of movement, and
lessening the risk of ashes and soot depositing in the flues. To effect
these objects there are spiral or twisted plates of sheet metal inserted
within the tubes. These plates are about the same width as the interior
diameter of the tube and twisted into a spiral or auger shape, so that the
gases receive a rotary movement in passing through the tube, hence, the
heated products of combustion are caused to impinge upon the surface
of the tube by the centrifugal action, and between these twisted sections
there are spaces forming combustion chambers in which the gases
commingle and are thoroughly consumed. These twisted sections are
preferably connected together by wires or rods, so as to maintain the
sections in their proper positions relatively to each other. The centri-
fugal action of the gaseous products of combustion tends to keep the
tubes clean, and lessen the deposit upon them of ashes or carbon.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Jensen in the Great Seal Patent Office on
the 17th May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
JENSEN, of 33, Chancery Lane, in the County of Middlesex, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of November, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Peter Jensen, Her special
license that I, the said Peter Jensen, my executors, administrators, and
assigns, or such others as I, the said Peter Jensen, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term

page_text: therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
TUBULAR FLUES FOR STEAM BOILERS," a communication to me from abroad
by Lewis Benjamin Halsey and Robert Hamilton Deaderick, both
of the City and State of New York, United States of America, upon
the condition (amongst others) that I, the said Peter Jensen, my
executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the
Great. Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Peter Jensen, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, reference being made to the Drawing hereto
annexed and to the letters and figures marked thereon (that is to
say):-
In the tubular flues of steam boilers the gaseous products of com-
bustion pass directly and unobstructedly through such flues, and
consequently the greatest heat is in the center of the flue, and the
motion is more rapid at and near the center than it is immediately
contiguous to the surface of the flue tube; this is especially the case.
where the flue becomes roughened by a deposit of ashes or soot.
The present Invention is for directing the heated gases into more
intimate contact with the tubes, checking the speed of movement, and
lessening the risk of ashes and soot depositing in the flues. To effect
these objects there are spiral or twisted plates of sheet metal inserted.
within the tubes. The plates are about the same width as the interior
diameter of the tube, and twisted into a spiral or auger shape so that
the gases receive a rotary movement in passing through the tube, hence
the heated products of combustion are caused to impinge upon the
surface of the tube by the centrifugal action, and between these twisted
sections there are spaces forming combustion chambers in which the
gases commingle and are thoroughly consumed. These twisted sections
are preferably connected together by wires or rods, so as to maintain the
:

page_text: sections in their proper positions relatively to each other. The centri-
fugal action of the gaseous products of combustion tends to keep the
tubes clean, and lessen the deposit upon them of ashes or carbon.
In the Drawing,-
Fig. 1 is a vertical section of a portion of the improved flue tube, and
"
2 is an elevation of a lathe adapted to twisting the plates.
The spiral or augur shaped plates a are of sheet metal twisted as
hereafter described, and they are nearly as wide as the interior diameter
of the flue tube 6 and of the desired length. The spiral plates are
connected by wires or rods c so as to make the series of plates flexible
or chain like, in order that there may be no difficulty in inserting them
in tubes of boilers already in use, and where the fire-box front would
form an obstruction if the spiral was not in sections and flexible. The
spiral sections detain the heated gases in their passage through the flue
tube, and cause such gases to travel from the center of the flue to the
surface of the tube, and this rotary or centrifugal action of the flame
and gases tends to keep the tubes clean, and lessens the deposit upon
them of ashes or carbonaceous matter, consequently the tubes are kept
in a highly heated condition. The space d between two of the spirals a
forms a combustion chamber, in which the heated gases commingle and
are thoroughly consumed. To twist the sheet metal into the spiral
shape a lathe is employed as shown in Fig. 2. One end of the strip of
metal is held in the vise e upon the face plate f, and said face plate is
upon a revolving mandrel as usual; the other end of the strip is firmly
secured in the vise upon the slide rest h. As the twisting progresses by
the revolution of the mandrel and vise e, the slide h is moved gradually
towards the vise e by the attendant, so as to keep the proper tension
upon the twisted strip and prevent it being broken. After the twisting
is completed the spiral is removed from the lathe, and cut into the
proper lengths to form the sections a.

page_text: Third. The method herein specified of directing the heated products of
combustion upon the interior of the flue tubes by twisted or spiral
plates introduced within such flue tubes, substantially as set forth.
Fourth. The means herein specified for twisting the metallic flue strip
consisting of the revolving mandrel and vise and movable head block
and vise, as specified.
In witness whereof, I, the said Peter Jensen, have hereunto set
my hand and seal, this Sixteenth day of May, in the year of our
Lord One thousand eight hundred and seventy-six.