IMPROVEMENTS IN METHODS OR MEANS OF SUPPLYING AIR UNDER PRESSURE TO FURNACES, AND IN APPARATUS THEREFOR 23
Year: 1881

page_text: LETTERS PATENT to Carl Haupt, Civil Engineer and Manufacturer, of Brieg,
Empire of Germany, for an Invention of "IMPROVEMENTS IN METHODS OR
MEANS OF SUPPLYING AIR UNDER PRESSURE TO FURNACES, AND IN APPARATUS
THEREFOR
23
PROVISIONAL SPECIFICATION left by the said Carl Haupt at the Office
of the Commissioners of Patents on the 25th January 1881.
CARL HAUPT, Civil Engineer and Manufacturer, of Brieg, Empire of Germany.
"IMPROVEMENTS IN METHODS OR MEANS OF SUPPLYING AIR UNDER PRESSURE TO
FURNACES, AND IN APPARATUS THEREFOR."
The object of these improvements is to introduce a regular supply of air,
previously heated if desired at a high pressure in parallel jets just above the
surface of the layer of coals into the gases evolved therefrom in a like direction
to that of the draft in the fire place, and also into the ashpit underneath the fire
bars when required and practicable. The compressed air may be supplied in -any
convenient manner, as from a blowing engine, fan, injector, or otherwise; and
although it might be introduced in a direction opposed to that of the draft, or
across it, I prefer to keep to the same direction, and thereby increase the draft
instead of checking it; and even if introduced from different sides, say, all four
at once, there would always be more or less gas in the centre untouched, and the
result would be less satisfactory.
In stationary boilers set in brickwork, etcetera, I carry a suitable flue or tube,
preferably in the brickwork itself, partly above and partly below the fire bars, and
provided with a regulating damper or equivalent device, and pierced with suitable
holes for directing the blast upon the gases in the furnace. I generally arrange
the damper so that when turned half way it will allow an approximately equal
area to both upper and lower jets. By this means an easy adjustment is obtained,
and the amount of each air current can be regulated as needed. When the flue
or tube passes in the brickwork suitable openings into the furnace must of course
be made for the jets. I prefer to place the firebars so low in the furnace that the

page_text: coals can be heaped up according to their quality, say, from 35 to 50 centimetres.
By winding the flue about, the air may be conveniently heated before it enters the
furnace. Where the firing takes place within the boiler flue I prefer to form the
casting which contains the fire door hollow, and heat the air therein, and this
method has the advantage of saving loss by radiation from the front.
A special
construction is advisable for "brown" (-
-) coal. In this case I may
place the fire door high up, and form the fire bars in steps, each bar below the one
before it and further into the furnace, like a small staircase. I again employ the
hollow front here, and direct both the upper and lower blasts downwards in the
direction of the bars.
In the case of locomotives the special blast may be dispensed with if desired, and
a suitable casing arranged, say, round three sides of the fire box, the projecting
ends being widened to receive the air forced in by the motion of the engine, and
special hollow stays conduct the jets through the front of the fire box above the
coal, and it is often not necessary to employ a blast underneath the bars, though
of course this can be done if necessary, and an injector or other means employed
for creating a highly compressed blast, as in the former cases.
It should be observed that generally the economical working of this system is
to a considerable extent dependent upon the setting of the damper, and it is
therefore important that the stoker should be able to ascertain at any time the
condition of the fire. For this purpose I employ, where practicable, a wide
observing tube, bent at right angles where necessary, and having a small piece of
looking glass in each bend placed at an angle of 45°, thus reflecting the image of
the flame to the front.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed.
by the said Carl Haupt in the Great Seal Patent Office on the 23rd July
1881.
CARL HAUPT, Civil Engineer and Manufacturer, of Brieg, Empire of Germany.
"IMPROVEMENTS IN METHODS OR MEANS OF SUPPLYING AIR UNDER PRESSURE TO
FURNACES, AND IN APPARATUS THEREFOR."
The object of these improvements, which are applicable, with suitable modifi-
cation, to most kinds of furnaces, is to constantly introduce air, previously heated
and at high pressure, from the frontside of the generator in parallel rays or jets,
and just above the surface of the layer of coals into the gases evolving therefrom
in such a manner that the direction thereof will coincide with the direction of the
draft in the fireplace.
In the accompanying Drawing the arrangements of fireplaces for this purpose
are shown. For the nature of the thing it is of course immaterial whether the
compressed air is furnished by a cylinder blowing apparatus, by a ventilator, by a
steam injector, or the like.

page_text: The direction of the air driven into the fireplace however can be variously
chosen. It might be introduced from the fire bridge in a direction contrary to that
of the draught, thereby however the flame would be choked and compressed, and
a narrow pointed flame would be produced. Introduction of the same from one,
from two, or preferably from four sides, in which case the fireplace is divided by
a central partition, will always leave a central strip of the quantity of gases
untouched and unpenetrated, as the air is immediately on entering directed away
by the draught of the fire; and this construction would also be difficult to execute
in tubular and in firebox boilers.
A second important point consists in conducting a part of the compressed air
under the fire bars into the closed ash pit for regulating, and, if necessary, forcing
the development of gases, and that the relative proportions of the compressed air
conducted over and under the layer of coal, can be regulated in a simple manner
by the stoker. Without such regulation the firing. would in some cases work with
a considerable excess either of air or of gas.
This is effected by a damper or a similar device inserted into the air conduit
in that place where the upper conduit for the air branches off from the lower.
In Figures 1 and 2 the air is introduced underneath the boiler, and the fire bars
are straight for a cylindrical boiler. The grater is placed so low that the coals
may be heaped on it, according to their quality, to a height of 35 to 50 centimetres.
Through the tube a compressed air is introduced in the direction indicated by the
arrow, of which air, according to the position of the damper K, a part is led below
the fire bars by the tube a¹, and the other part is led through the tube a² above
the fire bars. The latter part of the air serves for the combustion of the gases
of the generator, and is heated in the suitably winding tube a², and is introduced
through numerous holes of the tube a³ over the door in the front wall in the
brickwork of the boiler. In the position of the damper shown in Figure 2, the
admission of air below the fire bars is cut off. In like manner by completely
raising the damper the admission of air above the fire bars may be cut off.
As a
rule the damper will be so set that a certain part of the air will be introduced
above and a certain part below the fire bars. The relative proportion of these
quantities can be easily regulated by setting the damper, by means of suitably
arranged levers and rods, from the stoker's place.
In the case of an internally fired boiler the previous heating and division of the
air can be effected in the same manner, as shown in Figures 3 and 4, and Figures 7
and 8, that is to say, by a register constructed of hollow casting, and hereinafter
described.
Figures 3 and 4 represent in horizontal and longitudinal sections the arrange-
ment of an internally fired boiler with straight grate as used for tubular or for
marine boilers. The flue is placed so low that the fuel can be heaped to 30 to 45
centemetre high. The hollow spaces in the register, which contains the door of
the furnace and of the ashpit, serve for previous heating of the air, and for thereby
diminishing the loss of heat by radiation into the surrounding atmosphere.
The compressed air is introduced at a-and arrives according to the position of
the damper K through the openings a¹ under the firebars and the openings a²
above the firebars into the mixed gases.
Figures 7 and 8 show in elevation and longitudinal section an arrangement
placed in front of the boiler and specially adapted for the consumption of "brown"
coal having a step grate. This coal is known in Germany as "brown" coal and
n France as "lignite."
The arrangement of the firing is similar to that in Figures 3 and 4, as compressed
ir is introduced at a into the hollow register and arrives into the spaces a² and a²,
ccording to the position of the damper K. From a¹ the air flows into the ashpit
or maintaining the development of gases, and from a² into the gases to cause
combustion of the same.
In Figures 5 and 6 is shown in longitudinal and horizontal section a plan of
iring for a locomotive boiler. As the compressed lower draught may be dispensed

page_text: with in this form it is only necessary to introduce secondary air into the fire box
if the fuel is kept up to such height that principally carbonic oxide gas is formed.
To this effect a horse shoe shaped tube is so placed around the fire box that its open
widened ends a catch the air when the engine is travelling and allow it to escape
through hollow stays a¹ over the layer of coal.
It is of course clear that the hereinbefore described constructions may be used
for this firing by introducing strongly compressed air taken from a blower, an
injector, or the like, either only above the layer of coals or also into the closed
ashpit.
In all these methods of firing the economical working is to a great extent
dependent on the proper setting of the damper K.
The device shewn in Figures 9 and 10 allows its easy observation from the
stoker's place. For this purpose a wide observing tube s is placed at the side or
back of the first flue of the boiler, and is once or twice bent, preferably at right
angles, till it is conducted to the front of the boiler; into the rectangular knees
thereof small looking glasses or reflectors are placed at angles of 45°, or otherwise,
according to the angle of the knee which reflect the image of the flame to the
front. When several boilers are placed side by side the long part of the tube is
led either through the brick party wall between two boilers or over the brickwork
of the boiler.
CLAIMS.
1. The arrangement of channels or passages in or transversely before the front
of the furnaces, which channels are provided with a considerable number of holes
or outlets through which air under high pressure, and heated if desired, is driven
closely over the fuel and into the current of gases of combustion..
2. The arrangement of channels a¹, a², a³, for conducting the current of air,
which channels conduct compressed air under as well as over the firebars, and are
provided with a damper K or a similar device, by setting which the relative
proportion of the air entering above and below can be regulated.
3. The herein described construction and arrangement of hollow castings in the
front of the furnace, by which the heating distribution and introduction of either
a natural or artificial current of air as well below as above the firebars is rendered
possible.
4. The device for observing the flame from the stoker's place by means of one
or more reflectors placed at suitable angles in a sight tube.
In witness whereof, I, the said Carl Haupt, have hereunto set my hand and
seal, this Twentieth day of July, in the year of our Lord One thousand
eight hundred and eighty one.
ADT TTTTG
CARL HA
וזיזוזזי
(L.S.)