Improvements in or relating to Heating Apparatus.
Year: 1894

page_text: Date of Application, 16th Aug., 1894-Accepted, 29th Sept., 1894
Improvements in or relating to Heating Apparatus.
A communication from PAUL RICHARD HORN, of Dresden-Neustadt, Saxony, in
the Empire of Germany, Manufacturer.
I ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,.
Chartered Patent Agent 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 relates to a low-pressure steam stove, heated by gas or equivalent.
which by its compact and independent arrangement has an exceptionally good
heating effect.
This low-pressure steam stove or heating apparatus consists essentially of a
bottle-shaped steam-generator, and of any desired number of externally ribbed
pipes arranged on each side of and above the upper part of the steam-generator or
boiler. The latter has a central pipe or flue passing through it as an outlet for the
combustion products, and is provided with a chamber, for the reception of the gas
or other burner or equivalent in its lower and wide part. To facilitate the
utilisation of the heated gases, a fire-box with water-tubes, or a sheaf or upright
fire-tubes, may be centrally arranged in the lower part of the steam-generator, as
hereinafter described. A most important and essential feature in the new low-
pressure steam stove or heating apparatus is the application and use of an
automatically working regulating arrangement, by which the heating of the
steam-generator is brought into constant agreement or correspondence with the
actual useful heating effect developed by the stove, by means of the self-acting
influence brought to bear on the supply of gas or equivalent to the burner. This
is effected in such manner that whenever a prescribed maximum of pressure (corre-
sponding to a particular temperature of the steam, as is well-known) the supply of
gas to the burner is partially interrupted or entirely cut off.
Such a regulating arrangement is hereinafter described, with several modi-
fications.
In the accompanying drawings,
Fig. 1 is a longitudinal vertical section of the low-pressure steam-heating
apparatus, with a partial elevation of the ribbed pipes ;
Fig. 2 is a side elevation of the apparatus showing one of the ribbed pipes in
section;
Fig. 3 is a cross-section of the fire-box shown in Fig. 1;
Figs. 4 and 5 are, respectively an elevation and a horizontal section as seen from
above, of a fire-tube arrangement which may be used in substitution for the fire-box
shown in Fig. 1; and
Figs. 6, 7 and 8 are separate illustrations of different modifications of the
regulator above-named, shown in vertical section.
A A' is a steam-generator, whereof the wider, lower part rests on a suitable
base or feet, and the upper, contracted part A', where the steam collects, carries
the group of ribbed pipes B, which are arranged on both sides of A' and connected
with the latter as well as with each other by the supporting and connecting pipe-
lengths b. The cock with its hopper (shown on the left of Fig. 1) is designed to
be used for filling the steam-generator with water; 2 is a pressure-gauge.
pipes a serve to reconduct, to the steam-generator A, any accumulations of
condensed water from the steam in B B. C is a vessel, for the reception of the
stand-pipe C', and connected by the pipe c with the upper horizontal main B of
[D037
The

page_text: the group of pipes forming the apparatus. For the steam-generator fittings the
necessary steam and water cocks and water-gauge glass are also provided.
At the bottom of A, below F, is located the gas or equivalent burner D, fed
through the pipe d, fitted, as will be seen farther on with the gas-supply regulating
device already mentioned. The heated gases generated by the gas-burner ascend
to the top of the apparatus, throughout the whole steam generator A A', by the
flue or outlet pipe E, passing through a stuffing-box in the end cover of A¹, and
thence escaping into a chimney-flue or the open air.
It will be found very advantageous, at this point, not merely to allow the gas-
flames to burn directly inside E, but rather to introduce one or other of the two
apparatus now about to be described.
For the object aimed at, as shown in Fig. 1, a fire-box F is placed on the bottom
inside the steam-generator, so as to be surrounded with water, with an open bottom
and having the escape-flue E fixed to its top. This fire-box is traversed
diametrically by a number of water-tubes f (see also Fig. 3) communicating with
the rest of the water in the steam-generator, and so arranged one above the other
that their open ends form two spiral rows or orifices in the fire-box casing,
as shown, and that their whole external surface is played upon by the flames
and heated gases generated above the burner, so that brisk circulation of the
water through them is created, and a rapid and effective heating of, the same is
effected.
The same object is attained, if, instead of the fire-box F, the arrangement
illustrated in Figs. 4 and 5 be adopted. This consists of a vertical group of flue
tubes G connecting a lower open cylindrical combustion-chamber g with another
similar upper one g' to which the escape-flue or chimney E is attached. The gas
or equivalent burner D is contained in the lower fire-chamber g, and the heated
gases ascend freely through the vertical flue tubes G, around which the water
circulates and is rapidly heated while the gases escape through E.
In order to regulate and maintain the heating of the steam-generator in
proportion to the heat radiation from the burner or stove, and without constant
attendance and watching so as to bring about an even and regular heating of the
room, an arrangement has been adopted, whereby when the steam-pressure rises
above a certain prescribed amount the supply of gas to the burner is cut off either
entirely or partially. To this end the U-shaped bent pipe H Fig. 2 is connected
with the steam-space A A' at such a height that the inlet or mouth of the pipe can
never be reached by the level of the water in the steam-generator A.
The outer or rising arm of the pipe H terminates in a shell or case H', in which
a float, actuated by a column of mercury in the bend of H, rises and falls. When
the inner and outer pressure is equal, the mercury in the two legs of the bend of H
stands at the same level; but should the boiler-pressure exceed that of the atmo-
sphere or that of the still higher gas-pressure prevailing in the case H¹, the mercury
in the outer leg of the bend H will rise, and with it the float. Further, however, the
two pipes d and d¹ are also connected with the case H¹; the former, as has already
been said, leads to the gas-burner D, while the latter d' comes from the gas-service-
pipe, and is provided with the cut-off cock D¹. The float I is made (in this arrange-
ment) of the form shown in Fig. 6, and, if the boiler-pressure becomes too great, its
conical point i is lifted into the corresponding conical seat formed in the mouth of
the pipe d'. In this situation, if, i and d' come into close contact, the supply of gas
from d¹ to d would be completely cut off. But, in order that the flame of the
burner D should not be extinguished, but only kept low, so that when the boiler-
pressure consequently sinks, it may again be fully lighted up, the conical point i of I
is provided with grooves, and thus the supply of gas is not entirely cut off, but
ouly greatly reduced, leaving just enough supply to keep a minute flame burning.
Instead of the float I being provided with grooves, it may also be allowed to make
a complete closure with d', and, outside of and above the range of the valve-seat, a
small connecting-pipe d² may be inserted between d¹ and d, as shown in Fig. 2.
Therefore, in this case also, even when the mouth of dis entirely closed by I,

page_text: a small quantity of gas still obtains access to the gas-burner and maintains a feeble
flame.
When, after the gas-supply to the burner has been almost cut off, the boiler-
pressure (as may happen) continues to rise a little, the mercury might be caused to
overflow from the case H' into the gas pipe; to prevent such an escape or over-
flow of mercury, as shown in Fig. 2, the pipe d after leaving H' is not carried
directly downwards, but first upwards before the bend of its downward turn.
The unexpected overflow of mercury into d may also be prevented by making
the float of such a shape as to close the mouth of d in the case as well as
that of d¹.
Such an arrangement is illustrated in Fig. 7. In this case the float has the form
of a sphere I', and the two mouths of the pipes d and d' are placed side by side, as
shown in the case H': this double mouthpiece is cast in a common casting and so
arranged that the sphere I¹ fits tightly into it. The functions of the small
connecting pipe 2 are fulfilled by the small orifice ³, formed in the partition wall
separating the two pipes d and d¹.
For the same purpose, the float can be formed in the shape of a double cone-
valve, as shown in Fig. 8, consisting of the two cone-valves i and on the same
spindle closes the valve-seat h formed within the case H¹ below the inlet end
of d, while closes the outlet end of d¹ in the same manner. By means of the
screwed spindle of, which screws into female screw of i and is secured by a
screw-nut, the distance between i and can be so adjusted that when i lies
closely on its seat, there may be sufficient room still left between ¹ and¸¹ to
allow enough gas to pass through d, to the burner D, to maintain a feeble
flame.
In this low-pressure steam stove or heating apparatus various parts may be
modified, without departure from the essential principle and scope of the
invention.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent, and in what
manner the same is to be performed, I declare that what I claim is :-
1. A heating apparatus characterised by a bottle-shaped steam-generator
provided with a central inner flue-tube E and heated at its lower and wider
part A by a gas or other burner or equivalent D while the heat-radiating externally
ribbed pipes B are arranged parallel with and at the same height as its upper
and contracted part A¹ substantially as described and illustrated in the accom-
panying drawings.
2. The combination with heating apparatus such as described in Claim 1 of a
fire-box E with water tubes f and burner D in the lower and larger part A of the
steam-generator substantially as described and illustrated in the accompanying
drawings.
3. The combination with heating apparatus such as described in Claim 1 of a
sheaf of fire-tubes G in the lower and larger part of the steam-generator A
connected below with a fire-chamber g containing the burner and above with a
fire-chamber g' and with the escape-flue E passing through the contracted part of
the steam generator substantially as described and illustrated in the accompanying
drawings.
4. In heating apparatus such as described in Claim 1 the arrangement of an
automatic regulating device consisting of a bent or U-shaped pipe such as H in
communication by one leg with the steam generator and containing a column of
mercury and of which the other leg by means of a case H' containing a float such
as I is connected with the gas-supply-pipe (dd) the arrangement being such that
whenever the steam-pressure in the steam-generator exceeds a certain pre-
determined amount the float is raised and caused to partly or wholly cut off the
supply of gas to the burner substantially as described and illustrated in the
accompanying drawings.

page_text: 5. In a regulator for controlling the supply of gas to a heating apparatus such
as described in Claim 1 a ball or sphere such as I which simultaneously closes the
two adjacent mouths of the pipes d' and d in the case H¹ for the purpose of
preventing any overflow of mercury therefrom into the pipe d leading to the
burner substantially as described and illustrated in the accompanying drawings.
6. In a regulator for controlling the supply of gas to a heating apparatus such
as described in Claim 1 a float formed of two cone valves such as i i¹ of which
the lower one i (beneath the pipe d leading to the burner) plays on the seat / in
the case H' while the other the higher one plays on the seat in the mouth of the
gas-inlet pipe d' and by the aid of the screwed-valve spindle the two cone-
valves (i) are adjustable in relation to each other substantially as described and
illustrated in the accompanying drawings.
7. The combination and arrangement of parts constituting the complete heating
apparatus substantially as described and illustrated in the accompanying drawings.
Dated this 16th day of August 1894
W. P. THOMPSON & BOULT,
Agents for the Applicant.
W. P. THOMPSON & BOULT,
Agents for the Applicant.