Improvements in or relating to Furnace Bridges and Air Supply thereto
Year: 1898

page_text: Date of Application, 26th July, 1858-Accepted, 5th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in or relating to Furnace Bridges and Air Supply
thereto,
I, ERNST SCHUMACHER, of Leer, in the Empire of Germany, Builder, 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 improvements in furnace bridges for steam boiler fires
or the like and is for the purpose of utilizing combustibles in a more efficient
manner so that the unburnt ingredients of the fire gases coming from the furnace
are completely burned and the development of smoke is avoided.
In the present invention not only fresh air is introduced to the fire gas behind
the furnace bridge or the front part thereof, but by the construction of the furnace
bridge the fire gases and air are mixed intimately, the passage of the gases to be
mixed taking place upon the large surface of the furnace bridge which consists
of several pieces having a regulating arrangement for the introduction of the air.
In the annexed drawing:-Fig. I is a longitudinal section through the middle
of the fire tube showing the furnace bridge in vertical section. Fig. 2 is a hori-
zontal section through the middle of the fire tube showing the furnace bridge in
plan. Fig. 3 is the back view of the furnace bridge. Fig. 4 is a front view of the
furnace bridge on the left of the dotted line and the front view of the furnace
showing operating levers on the right of the dotted line. The furnace bridge
lying in the fire tube 9 of the boiler consists of three parts 1 2 3.
The parts 1 and 2 are arranged in the capping plate or frame 5 which is con-
structed in such a manner that between the parts 1 and 2 a large pit or space 4
is formed which can be closed entirely or partially by means of the slide 6.
On the back of the capping plate or frame 5 an up and down movable frame S
is arranged supporting the third and thus movable part 3 of the fire bridge.
The complete combustion of the fire gases is obtained by the peculiar effect of
the displaceable part 3 of the furnace bridge in connection with the pit 4.
The fire gases passing the bridge 1 receive a regulatable air draught through 4:
the mixing is favored by the part 2 overtopping the pit, against which part of the
mixed air and gases is brought in order to be further mixed whilst passing over
the small pit 7 and the bridge 3 where the unburnt particles are consumed.
The intermediary bridge 2 protects the movable bridge 3 against too great
influence of the fire gases and also prolongs the mixing as much as possible.
In order to regulate the flow of the mixture in the mixing room upon the large
bridge and to reinforce it, if necessary by an air blast the bridge 3 can be moved
more or less upwards or downwards in order to receive the fire gases and to stop
them in their current giving hereby a back flow to them into the pit 4.
The slide 6 and the part 3 are manipulated the one independently from the other
in order to occupy any required positions between the full lines shown in Figs. 2
and 3 and also any required position of the slide 6 and the part 3 between the dotted
lines in these figures. The intermediate movements of all the mentioned parts
makes it possible to regulate entirely the proportion of the air exit section from
DQ17

page_text: the mixing room to the air entrance section of this room in such manner as may
be required in order to completely consume the combustibles and to avoid the
development of smoke.
The construction of the bridge and the mechanism for moving the movable parts
shown in the drawing is as follows:
The frame 5 fills the under part of the fire tube opening outwards and carries
the feet 10 and the side shoulders 11. On the back part are pieces 12 with plate
irons 13 screwed thereon serving as guides for the cross pieces 14 of two brackets 15.
On these latter the frame 8 is rivetted which serves as a support for the bridge
part 3.
The frame 8 is movable upwards and downwards by means of the cam 16 turn-
able in the eye 17 arranged on the plate 5 and by means of the lever 18 the rod 19
and lever 20. By turning the rod 23 in the eye 22 secured on the capping plate
The bar 23 can be
and front plate 25 (Fig. 4) the frame 8 is raised or lowered.
turned by means of the hand lever 26; the latter is moved before the segment 27
and can be secured thereon like the regulator rod of a locomotive by means of a
spring nose 28 shown dotted in Fig. 4 engaging in one of the grooves 29 of the
segment 27. The chain 31 guided upon the pulley 30 has on the other end a
counterweight to balance the weight to be drawn up the slide 6 lying upon the
guides 21 carries a bolt 32 in order to be moved by means of the forked rod 33
turnable in the eye 34 which is fixed on the cross piece 24 of the capping plate 5.
This cross piece 24 is used as a hind support for the grate bars (shown in dotted
lines in Fig. 1). The forked rod 33 opens and closes the slide 6 by means of the
bar 36 provided with handle 35 passing through the front plate 25, the cheeks 37
fastened on the shoulder 21 limit the movements of the slide to the front side.
Instead of the described means of movement the parts can be different provided
they have the same effect also the movable frame of the fire bridge can be other-
wise formed.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is:-
1. In a furnace bridge for steam boiler fires or the like the combination of two
fixed parts 1 and 2 having between them an air pit 4 capable of being closed
entirely or partially with a movable part 3 substantially as and for the purpose
described.
2. In a furnace bridge for steam boiler fires or the like the arrangement of a
frame 5 fitting with its back wall the under part of the tube opening 9 and forming
the pit 4 open below and supporting the two fixed parts 1 and 2 and also the
movable part 3 by means of the support frame 8 and framing 13 14 and 15 moving
between guides 12 and 13 means being provided for moving the frame 8 upwards
or downwards substantially as and for the purpose described.
3. In a furnace bridge for steam boiler fires or the like the arrangement of a
fixed frame 5 filling with its back wall the lower space of the fire tube opening 9
and forming the pit 4 open below the latter being closed entirely or partially by
means of a slide 6 lying upon guides 21 arranged on the side of the frame 5 means
for moving the said slide 6 substantially as and for the purpose described.
DJ h Oth Ja of T.... 1000
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, London.