Improvements in Air-heating Apparatus.
Year: 1889

page_text: Late of Application, 9th Sept., 1889-Accepted, 15th Mar., 1890
COMPLETE SPECIFICATION.
Improvements in Air-heating Apparatus.
I HEINRICH JOSEPH SIEPRATH Manufacturer, of Aachen in the Kingdom of Prussia
and German Empire, 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:-
The object of the present invention is the production of central air heating plant or
apparatus arranged with calorifiers or air-stoves by means of which it is possible to
introduce into the rooms to be heated, air complying with the sanitary requirements
at the lowest possible cost of fuel and labour.
The calorifiers consist of a combined system of tubes fitted with ribs projecting
about 5 centimeters and a complete smoke consuming apparatus and which like the
entire plant may be applied in various ways and in any size, with single or double
fire places.
The tightness of the connecting joints of the several bodies (which is calculated
upon the basis of the fewest possible in number) is completely secured by a number
of locks or other fastenings.
The heating bodies are cleaned from outside the heating room: The fire places
fitted with intermediate shell and diagonal grate are set up in front of the heating
room and separated from it by an intervening space. These arrangements effectually
prevent the heating bodies from becoming red hot and coal gases from finding access
to the heating chamber.
The fire places are made of wrought iron plates and lined with masonry work of
fire-bricks. In order to prevent the heat eventually radiating from the iron plates
from entering into the space where the apparatus is set up a wall 13 centimeters or
thereabouts in thickness is according to circumstances run up at a great distance
from the iron plates. A similarly large space is also reserved between the double
fire places in order to separate the two fires from each other. These intervals of
space serve at the same time as apparatus for burning smoke and vitiated air and
are regulated by throttle-valves with simultaneous action.
Owing to the circular shape of the heating room and the arrangement for admitting
the fresh air into it the fresh air to be introduced into the rooms to be heated moves
with even speed. The heating room consists of three walls made of fire-brick plates
which are separated from each other by three intervening spaces the size of which
corresponds to that of the calorifier. Through these intervening spaces the fresh air
passes on its way to the heating room and in the meantime it is purified and kept
moist by means of water sprays in the intervening spaces nearest to the chamber.
In order to be able to supply each space with moisture according to requirement, a
reservoir and a regulating apparatus for admitting the vapours to the corresponding
rooms have been set up above the fire place for generating vapour.
The annexed drawings illustrate the improved heating apparatus in the clearest
manner possible.
Sheets 1 and 2 shew in various ways the system and arrangement of the entire
plant.
Sheets 3 and 4 represent the separate parts of the plant notably those of the
calorifiers.
Fig. 1 is a horizontal section taken through lower part of calorifiers.
Fig. 2. horizontal section through fireplace.
Fig. 3. horizontal section above the tubes.
Fig. 4 vertical section on line g-h Fig. 1.
Fig. 5 vertical section on line a, b Fig. 1.
Fig. 6 vertical section on line c-d Fig. 1.

page_text: gs. & 3 Horizontal sections through the fireplace.
Fig. 10 vertical section on line i, k Fig. 8.
Fig. 11 vertical section on line l, m Fig. 9.
Fig. 12 plan view of lower connecting box.
Fig. 13 horizontal section through lower connecting box.
Fig. 14 horizontal section on line n--o Fig. 16.
Fig. 15 vertical section on line c-d Fig. 14.
Fig. 16 vertical section on line α, b Fig. 14.
Fig. 17 vertical sections on lines e, f, g, h, i, k.
Figure 18 horizontal section on line s, t, Fig. 17.
Fig. 19 horizontal section of the lower connecting box on line u―v Fig. 21.
Fig. 20 plan view of lower connecting box.
Fig. 21 vertical section on line l, m Fig. 18.
Fig. 22 horizontal section of connecting joints on enlarged scale.
Fig. 23 vertical section of connecting joint cover on line w, a Fig. 24.
Fig. 24 plan view of connecting joint cover.
Fig. 25 horizontal section of coating or wall of calorifier constituting the heating
chamber (natural size).
Figs. 1 to 7 Sheets 1 and 2 represent the plant combined and Figures 8 to 11 shew
it singly. The fire places of the calorifiers are separated from the heating room by
the intervening space. The bodies nearest to the fire places are prevented from
becoming red-hot by rings of fire-brick b. The fuel is fed into the fire lying on the
diagonal grate c through the intermediate shoot d. The doors e of the fireplaces
are fitted with regulating discs and can be hermetically closed by means of a screw
arrangement. The fire places consist of wrought iron plates and are lined with
masonry work of fire brick. The walls g situate at a certain distance according
to circumstances in a lateral direction from the wrought iron plates keep the heat
radiating eventually from the fire places densely and closely shut in around the fire
places.
The combined calorifier Figs. 1 to 7, Sheets 1 and 2 consists of calorifiers of various
sizes which may be used also separately; see Sheet 2 Figs. 8 to 11. The bodies are
fitted with ribs projecting out to a distance of 5 centimeters.
Owing to the heterogeneous shape of these two simultaneously acting calorifiers
it is possible to place them in such a position as to distribute the heat in the heating
chamber always evenly both with double and single fire places.
The extent of the heating surface to be détermined is derived from the cross-
section of each separate body.
On heating, the hot gases pass from the fire through the tube h in the front
connecting box i where they are distributed to the right and left into the transmission
tubes and are reunited in the connecting box / whence they are carried back again,
either through the tube m into the smoke funnel or through the tube n, or
respectively o, into the fire to be consumed once, more according to the process of
consumption of either of them requiring it. The throttle-valves p, or respectively r,
fitted to the respective tubes at the entrance of the smoke-funnel and in the vicinity
of the fire places serve to regulate this apparatus for burning the smoke.
In the case of the combined plant, they are so arranged as to cause one throttle
of the larger calorifier to act in unison with that of the smaller one. They are
worked in a very simple manner. If the throttle on the sinoke funnel is to be opened
and the one on the fireplace closed, the levers is placed backward and vice versú if
the throttle on the smoke funnel is to be shut and the one on the fireplace opened.
If in the case of the double fire combined apparatus, Figs. 1 to 7, Sheets 1 and 2
the smoke is to be burned by means of the larger fire then as soon as both fires are
burning up fully, the lever at the larger fire is placed forward while that at the
same time the smaller one continues in the backward position. This causes the smoke
funnel of the larger fire to remain open while that of the smaller one is closed the
gases in which are compelled to pass at t through the tube o. leading to the larger

page_text: ire below, where they enter at u and are burned. This passage of the gases from one
are to the other may be effected alternately according to the condition of one or the
other of the fires requiring it. If the burning of the gases of the larger fire is to
be effected by means of the smaller fire, then as soon as the lever s is placed forward
at the smaller fire and that of the larger is placed backward, the gases pass at v
through the tube n leading to the smaller fire below in order to be burnt up in it.
If in mild weather, only one fire is to be kept burning the gases are conducted
through the apparatus not in operation and having arrived at the flue are carried
back partially to the same fire which produced them in order to be burnt there. If
therefore the larger apparatus alone is to be heated the lever at the smaller fire is to
be placed forward through which the throttle at the larger apparatus is closed and
the one at the fire of the smaller apparatus is opened; at the same time the lever at
the larger fire is placed half backward through which the throttle on the funnel of the
smaller apparatus and the one at the fire of the larger apparatus are only half
opened. After that has been done, the gases of the larger fire pass through the
larger apparatus as far as the throttle on the funnel, turn then at through the
tube n in the direction of the smaller fire space, whence they pass through the smaller
apparatus as far as the throttle on the smoke funnel, where a portion of them enters
into the funnel and another portion returns through the tube o to the aperture u into
the same fire where the gases were generated in order to be burned there. The
same process takes place at an inverse ratio if the smaller apparatus only is to act.
The gases passed through the tubes of the apparatus not in operation heat the latter
jointly with the heat radiating into the chamber out of the apparatus at work but
which again turns to the benefit of the total working of the system by the back
radiation into the chamber through which only the most absolutely necessary portion
of heat required for producing the draft escapes into the smoke funnel owing to
which besides a complete consumption of the smoke the utmost possible use is
obtained from the heat both in the case of single and double fires.
In the case of the single apparatus Figs. 8 to 11 as soon as the fires are burning up
well the levers s are placed forward, through which the throttle valves at the smoke
funnel are half closed whereas the throttles at the fires are opened entirely. Owing to
this arrangement a portion of the gases pass on to the smoke funnels while the other
returns to the fires.
The air required for burning the smoke passes through the apertures w in the
enclosures walls erected at the fireplaces into the intervening spaces where it is
heated by the radiation of the iron plates bordering surrounding the fires and through
the portion of the smoke tube y passing through that place whence it returns through
the apertures into the fires.
The connecting joints which are of the fewest possible number are made tight by
means of several sand joints A Fig. 22 Sheet 4 which shews this joint in natural size.
Into the groove N cast on outside of the thickness of the wall to the connecting box,
having a width of 3 centimeters and a depth of 4 centimeters, previously filled with
sand, the tenon II formed on the tube and having a thickness of 1 centimeter, fixes
itself in such a manner as to cause the inner thicknesses of the walls of the bodies to
be joined without any projection to stand vertically one on the other. By the
tenon II fitting into the groove 1 the sin is pressed hard together owing to which the
tenon stands between two tolerably firm strata of sand having each a thickness of
1 centimeter. Commencing at the outer wall of the groove I, a cup III having
a depth of about 6 centimeters is cast on. After the calorifier has been finally
mounted this cup is also filled with sand and closed by means of the lil IV and
fastened together by means of screw-hults. See details Fig. 24 Sheet 4. The
expansion of the castings setting in with the heating is not hindered by this
operation.
The calorifiers are cleaned from the outside of the heating chamber by means of
brushes and hook-shovels, through the cleaning box a and it can be effected without
disturbing the working of the plant. The fire-brick plates for the enclosure
walls of the heating-chambers (see detail Fig. 25 Sheet 4) are provided at the

page_text: extremities where they meet with slits c¹ and leaves d'. After having having
covered the small sides of the leaves with fire-brick cement the plates are pushed
close together and the slits filled firmly with fire-brick cement. By means of the
connecting wedge thus produced the untightening and the displacement of the fire
brick plates are prevented.
The air spaces e¹ and e² between the fire brick plates serve for admitting fresh
air into the heating chamber. Moreover in these the air passing through them is
purified and moistened. The air to be introduced enters from outside through the
passage into the air-space e¹ and rises through it into the air-space e² where a
fine spray diffuser g' is fitted up for producing the water-spray. Owing to this
arrangement the air increases in moisture and consequently also in weight, and falls
naturally together with the water spray to the bottom, passes over the water surface h¹
below and is thus completely purified, the moist and gentle current enters through the
aperture into the heating chamber whence after having become warm, it passes
through the apertures at a uniform rate into the rooms to be heated. The water
collecting in the air space e² is conducted through the tube e¹ fitted with a water-
fastening, into the receptacle m¹² fixed underneath the fire place where by means of
heat emanating from the fire in a downward direction it is evaporated. The
steam generated is led to the fire behind the plate n¹ close behind the grate.
For moistening and regulating furthermore the air of the rooms to be heated, a closed
receptacle of is fixed up above the fire places. On the covering-lid p' of this
receptacle there are as many tubes fitted with shut off cocks as there are rooms to be
heated. The cross section of each tube is in proportion to the quantity of the air to be
introduced into that room to which the respective tube is to contribute the vapours
passing through it. The water which as required accompanies it is heated by the heat
radiating from the fire covers and the steam arising is introduced according to
requirement into the respective rooms on the centre of the covering plate this
receptacle is fitted with a somewhat salient neck on which reposes loosely a plate l
led by lateral guide rods which take the place of a safety valve. The water level for
the time being in the receptacle is ascertained by means of an open water level gauge
fixed in front of it, so that the water as soon as it exceeds the normal beight is led
through the aperture of the water-gauge by means of a small tube connected with it
below the fireplace where it evaporates. Figure 4 Sheet 2 shews clearly how the
vitiated air is brought back from the heated rooms. The vitiated air is led through
the vertical canals from the rooms into the clay pipes fixed borizontally underneath the
ground floor and thence into the vertical tube leading to the fire. An eventual
ricochet of the heated gases and smoke is prevented by the catch apparatus fitted in
the vertical canal s² Figs. 4 and 7 Sheet 2 passing through the fire-places by means
of the oblique lying plates I II, III, IV. The air eventually returning is caught up
in the gaps thus produced and finally mixes again with the vitiated air coming from
the heated rooms which can pass through the canal without any hindrance when it
enters again together with the latter through the aperture t¹ underneath the grate into
the fire.
The supply of air from the heating room necessary for burning may by means of
this arrangement be limited to the smallest measure.
The vertical canal 2 is in the case of the single plant Figures 7 to 11 Sheet 2
arranged laterally.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In calorifiers arranged with fire places established outside of the heating chamber
for the protection of the heating bodies from becoming red hot: the connection of the
heating drafts h, i, k in the air heating chamber with the tube of the smoke funnel m
and the tubes n and o returning to the fireplace and the arrangement of the throttle
valve p and in such a manner as to bring back a portion of the gases and smoke to
the fire to be consumed once more, while only the portion of the gases of combustion

page_text: necessary for effecting the draft passes into the smoke funnel as shown and
described.
2. In the calorifier hereinbefore described the hermetical fastenings A on the
heating body consisting of a tenon II groove II horizontal joint H H and fastening
cup III capable of being shut by means of a lid for preventing the escape of the
gases through the joints of the heating bodies in the heating chamber as shown and
described.
3. In the calorifier as herein before described the arrangement for the supply of
fresh air to the heating chamber through the vertical canals set and the arrangement
of the diffuser g' connected with them through which arrangement the air to be
heated is purified moistened and quieted as also the arrangement of the canal s' and
the oblique lying plates II III IV preventing the return of the fire gases for burning
the air brought out of the heated room as shown and described.
4. In the calorifier hereinbefore described the arrangement of a receptacle o¹ of the
fireplace outside of the heating rooms for generating vapours and the connection of this
receptacle through the tubes provided with taps with each of the rooms to be heated by
means of a tube g for moistening the air in the rooms to be heated and which
operation is capable of being regulated, substantially as described and represented in
the drawings annexed.
5. The improved arrangement and construction of apparatus for heating air
arranged to act substantially in the manner and for the purpose herein before fully
described and illustrated in the drawings hereto annexed.
1800
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, Agents for the Applicant.