IMPROVEMENTS IN FLUES FOR CHIMNEYS AND VENTILATING SHAFTS
Year: 1878

page_text: LETTERS PATENT to Anker Heegaard, of Copenhagen, Knight of the Royal
Order of Dannebrog, for the Invention of "IMPROVEMENTS IN FLUES FOR
CHIMNEYS AND VENTILATING SHAFTS."
Sealed the 12th November 1878, and dated the 17th May 1878.
PROVISIONAL SPECIFICATION left by the said Anker Heegaard at the
Office of the Commissioners of Patents on the 17th May 1878.
ANKER HEEGAARD, of Copenhagen, Knight of the Royal Order of Dannebrog.
"IMPROVEMENTS IN FLUES FOR CHIMNEYS AND VENTILATING SHAFTS."
This Invention of improvements in flues for chimneys and ventilating shafts is
especially applicable to chimneys or stoves with ventilation; the flues present a much
larger heating surface than common tubes, provided the last mentioned do not
occupy a larger volume than the improved flues or tubes.
The improvement is obtained by the particular form of the tubes, because the
exterior surface is larger in proportion to the space occupied by the flue, and soot is
prevented from sticking to larger portions of the interior sides of the tube, or in
every case will be prevented remaining there.
A portion of the improved flues or tubes is shown in the Drawing. Figure 1 is a
horizontal section, and Figure 2 a perpendicular view.
The horizontal section follows the line c, d, Figure 2; the perpendicular one is laid
through the middle of the tube.
The tube is made of a number of cups a', a², with open bottom, the one above the
other by turns, the narrow end and the wide one turned upwards, fitting closely the
one above the other.
The cups a are provided with flanges C³, and the cups c¹ with flanges C', to make
the one cup lie solidly over the other and to obtain a convenient fitting where
the lines meet between the cups. The upper part of the cups fits with its edges
into these flanges.
The smoke passes within the interior of the tube, while the air going to be
heated sweeps along the outer side of the tube,
"

page_text: Their sides
The cups a¹ and a² may be either round, or oval, or polysided.
may besides be sinuous, as may be seen in the Drawing, whatever the forni
theso sinuosities follow along the circuit of a circle, an oval, or any other closed
curve.
Upon the whole the shape of the cups may undergo many different variations
without changing the essential part of the Invention, provided only that the one
end is wider than the other.
If more cups are applied the one above the other they may be fastened by bolts going
through eyes of a more or less number of cups, and whose ends are provided with
heads and nuts outside the eyes of the two outer cups. The junction of the cups
may also be made otherwise.
It will be seen by the description of the improved tubes that the outer surface is
larger than that of a cylinder with the same diameter as that of the tube where
it is widest. The heating surface will be much larger though than that of the
cylinder (according to exact experiments, 40 per cent.), because that the soot cannot
deposit itself, or at least not remain in any case on the parts of the walls of the tube
sloping thus that their interior sides are turned downwards.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Anker Heegaard in the Great Seal Patent Office on the 15th
November 1878.
ANKER HEEGAARD, of Copenhagen, Knight of the Royal Order of Donnebrog.
"IMPROVEMENTS IN FLUES FOR CHIMNEYS AND VENTILATING SHAFTS."
This Invention of improvements in flues for chimneys and ventilating shafts is
especially applicable to chimneys or stoves with ventilation; the flues present a much
larger heating surface than common tubes, provided the last mentioned do not
occupy a larger volume than the improved flues or tubes.
The improvement is obtained by the particular form of the tubes, because the
exterior surface is larger in proportion to the space occupied by the flue, and soot is
prevented from sticking to larger portions of the interior sides of the tube, or in
every case will be prevented remaining there.
A portion of the improved flues or tubes is shewn in the Drawing; Figure 1 a
horizontal section, and Figure 2 a perpendicular view.
The horizontal section follows the line c, d, Figure 2; the perpendicular one is laid
through the middle of the tube.
The tube is made of a number of cups a¹, a², with open bottom, the one above
the other by turns, the narrow end and the wide one turned upwards fitting closely
the one above the other.
The cups a are provided with flanges be, and the cups a' with flanges or collars
¹, to make the one cup lie solidly over the other and to obtain a convenient fitting

page_text: where the lines meet between the cups. The upper part of the cups fit with their
edges into these flanges.
The smoke passes within the interior of the tube, while the air going to be heated
sweeps along the outer side of the tube.
The cups a' and a may be either round, or oval, or polysided. Their sides
may besides be sinuous, as may be seen in the Drawing, whatever the form
these sinuosities follow along the circuit of a circle, an oval, or any other closed
curve.
Upon the whole the shape of the cups may undergo many different variations
without changing the essential part of the Invention, provided only that the one end
is wider than the other.
If more cups are applied the one above the other they may be fastened by bolts
going through eyes of a more or less number of cups, and whose ends are provided
with heads and nuts outside the eyes of the two outer cups. The junction of the
cups may also be made otherwise.
It will be seen by the description of the improved tubes that the outer surface is
larger than that of a cylinder with the same diameter as that of the tubo where it is
widest. The heating surface will be much larger though than that of the cylinder,
according to exact experiments 40%, because that the soot cannot deposit itself, or
at least not remain in any case on the parts of the walls of the tube sloping thus
that their interior sides are turned downwards.
Having now described and particularly set forth the nature of the said Invention,
and the manner of carrying the same into effect, I would have it understood that
I claim, the tubes for chimeys or ventilating shafts, substantially as described, for
the purposes set forth.
In witness whereof, I, the said Anker Heegaard, have hereunto set my hand
and seal, this Seventh day of November, in the year of our Lord One
thousand eight hundred and seventy-eight.
ANK. HEEGAARD. (L.S.)