hot air stoves furnaces
Year: 1888

page_text: I, HENRY TILDEN, Gentleman, of the City of Minneapolis, County of Honnepin,
State of Minnesota, United States of America, 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 :-
My invention relates to improvements in tubes for hot air stoves, furnaces and the
like and it consists in the peculiar sectional heating-tube hereinafter described and
claimed.
My invention has for its object to provide a simple and efficient means for collecting,
conducting, and distributing heat. It was designed primarily for use in connection
with a heating-furnace with a view of economizing fuel and heating the fresh-air
without bringing it in contact with red-hot iron. Red-hot iron, as is well known, has
a deleterious effect on air which is to be breathed by living beings. It abstracts
the moisture gives off a poisonous gas itself, and allows the gases of combustion to
pass through it. These injurious effects it is essential to avoid, therefore, in the case
of a heating-furnace, and its adaptation to accomplish this end is an important feature
of my heating-tube. In other uses economy of fuel and quick heating are the
desired ends, without regard to the gases produced, and my tube is equally well
adapted for such purposes. In the former I do not bring the outside of the tube into
direct contact with the fire, and I pass the air through the interior of the tube. In
the latter case I might set the tube right in the midst of the burning fuel and pass
the material to be heated through the inside, as before. In still other cases I might
reverse the operation and conduct the heat from the inside to the outside of the tube
by passing the hot material through the inside. The tube, for example, would make
an excellent steam-heat radiator. In its construction my heating-tube combines
three principles, viz.: It gathers the heat by a very large surface, presenting a great
number of points exposed to the source of heat; secondly, it conducts the heat on
straight lines and on lines at right angles to the planes of crystallization of the cast-
iron and, thirdly, it imparts or radiates the heat by the utmost possible surface,

page_text: :
t
presenting a large number of points in intiniate contact with the material to be
heated.
The accompanying drawings-like letters of reference referring to like parts
throughout illustrate my invention.
Figure 1 is a plan view of a section of the tube. Figure 2 is a section on the
line X X of figure 1. Figure 3 is a side elevation of a tube composed of a series of
sections and the means of supporting the same in position, and Figure 4 is a plan
view of the top and bottom section of my heating-tube.
A is a section of a tube of such a length as may be most convenient for casting,
and of any desired diameter, preferably from four to six inches.
B is a section different from A, which is used for the top and bottom of the tube.
Section A is provided with a series of radiating-plates set in the periphery on a
line normal to a tangent at the point of intersection of the periphery and extending
inward to points near the center of the tube and outward any desired distance-as an
inch or two beyond the periphery. As many of these radial plates may be used as
desired. The section is also provided with a groove, a¹, on the top edge or rim of
the periphery, and the lower edge or rim is extended below the radial plates for
forming the joints. The lower edge or rim of one section sets in the groove on the
upper rim of another section, and the groove is filled up with fine sand or cement.
In this way a perfect sand joint is formed. By adding similar sections a tube of any
desired length may be formed. In putting together the, sections the joints or lines
formed by the radial plates are broken. The radial plates of any given section fall in
a line between the spaces of the radial plates of the next section. In this way a tube
is formed wherein the radial plates are in broken lines, a tortuous duct is presented
for the air or other material, and there is no open channel. In fact, the plates are so
thick that one cannot see through the tube.
.
When used for a furnace, the top and bottom sections B are made slightly different
from the others in this, that the radial plates are not used. The bottom section rests
in the sand-joint groove of a cap fitting over a corresponding hole in a bottom plate.
The top section connects by a sand joint with the upper or top plate of the furnace.
When a series of these tubes are put together and held in position by suitable upper
and lower plates and are heated by heat from fire-pots or other source of heat suitably
placed among the tubes and fresh air is supplied to the interior of the tubes by
suitable air-ducts below, a furnace is made. The absence of the radial plates on the
bottom sections gives access to remove any soot or ashes that may accumulate, and
their absence on top sections gives more space for the smoke and gases to pass in their
outward course to the smoke-flues.
For some purposes it may be desirable to have horizontal instead of vertical tubes.
In that case sand joints of loose sand are impracticable, and I connect the sections
by a screw-threaded joint, a screw-thread being cut on the outside of one rim
and a reverse thread on the inside of the other riin; or I use cement instead of sand
in the grooves, as shown, and hold the series of sections together by rods passing
through the sections and secured by bolt-heads and nuts to lips on the top and bottom
sections. These rods are shown in position in figure 3, and the lips on bottom and
top sections are shown in Figure 4.
I am the inventor of the peculiar furnace herein partly disclosed, and thereby
treserve the right to apply for Letters Patent on the same in another application.
A peculiar fact is revealed by one of the sections of this heating-tube. If heat be
applied to one of the rapid plates at, say, its outer extremity, it will be felt at its
inner extremity much sooner and of much greater intensity than at any point in the
rim equidistant from the point where the heat is applied. The explanation berein
given is that this is probably due to one of two things-viz., either that cast-iron
will conduct heat more readily on lines at right. angles to the planes of its crystals
or that heat will be conducted more rapidly on straight lines than on any other. The
former is considered the more probable cause. On the process herein disclosed for
applying that principle the right is reserved to apply for a patent in a subsequent
application.

page_text: Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what
I claim is :-
1. A heating-tube for furnaces and similar uses, consisting of a series of sections
provided with a series of radial plates extending inside and outside of said sections
and disposed on both sides longitudinally of the axis of said sections, the plates being
shorter than the sections and of similar form both inside and outside of the same, the
plates of each section being placed to break joints with the plates of the adjacent
section or sections, substantially as described.
2. A heating-tube for furnaces, consisting of sections, the sections intermediate the
ond sections being provided with radial plates extending inside and outside of said
sections and disposed longitudinally of the axis of the sections and of the same form
on both sides, the plates of each section being placed so as to break joints with the
adjacent section or sections, and connections uniting the end sections, substantially as
described.
3. A heating-tube for furnaces and similar uses, consisting of a series of sections
provided with a series of radial plates extending inside and outside of said sections,
the plates inside being of different lengths, but all disposed longitudinally of the axis
of the section, the plates of each section being placed so as to break joints with those
of the adjacent section or sections, substantially as described.
4. A heating tube for furnaces and similar uses consisting of a series of sections
each provided with radial plates set in the periphery of the section lengthwise of the
axis of the same, substantially as described."
5. A heating tube for furnaces and similar uses consisting of sections, the sections
intermediate the end sections being provided with radial plates disposed longitudinally
of the axis of the sections, the radial plates of each section being so placed as to
break joint with the plates of the adjacent section or sections, and connections uniting
the end sections, substantially as described.
1000