Improvements in Continuous Working Recuperative Gas-furnaces.
Year: 1895

page_text: Date of Application, 4th Jun., 1895-Accepted, 31st Aug., 1895
COMPLETE SPECIFICATION.
Improvements in Continuous Working Recuperative Gas-furnaces.
I, AUGUST DAUBER, of Bochum Westfalia, Germany, Merchant, 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 consists in such an arrangement of the flues for gas and air and
products of combustion of gas furnaces, that I obtain a continuous heating at one
and the same time, of the generator gas and of the air necessary for combustion,
by either parallel currents.in separate flues of the said gas and air and products
of combustion, or by opposite currents of the generator gas and air on the one side,
and the, heating products of combustion on the other side. In either case I can
arrange these flues either underneath the furnace or at any suitable distance
alongside, or above the furnace.
Before their entrance in the combustion space of the furnace, I mix in any
desired proportions, the beated air and heated gaseous fuel, by causing the gaseous
fuel under pressure to act as aspirator or injector for a certain quantity of heated
air, or also by making the heated air under pressure to act as aspirator. I use for
this purpose suitably arranged fornis of conducts or pipes and flues, for the gas,
heated likewise on its path to the aspirator and mixer of gas and air, regulating
at the same time their relative proportions in order to obtain the desired effects.
All these qualities, are inherent only to my invention, as obviously no furnace
with an accumulator of heat or with reversible gas flow can be arranged to have
such continuous action as my furnace arrangement. 1 likewise can arrange my
furnace flues for, either parallel or opposite direction of flow of gas or of air or of
both gas and air and heating agent, so that they reach the entrance of fuel and air
in the combustion chamber without altering at all the proportion of mixture of
the said gas and air.
The annexed drawing shows three different arrangements of flues underneath the
furnace, according to my invention.
Figs. 1 to 5 show the different sections of an arrangement of furnace and flues
for heating the air in parallel current, to the products of combustion alone, the
gaseous, fuel going straight to the burner, and there is:
Fig. 1 a longitudinal section, of the furnace along J-K of Fig. 3;
Fig. 2 a vertical cross section of furnace and gas-chamber;
Fig. 3 a horizontal section along 1-1 Fig. 1.
Fig. 4 a horizontal section along 11-II Fig. 1.
Fig. 5 a longitudinal section along II-111 Fig. 4.
Figs. 6 and 7 show a different arrangement of flues, i.e. for obtaining an opposite
current for the heating products to that of the fresh air;
Fig. 6 shows a longitudinal section of the furnace of this arrangement;
Fig. 7 a horizontal section along IV-IV Fig. 6.
Fig. 8 to 11 show the arrangement for simultaneously heating the air and gaseous
fuel by parallel current of heating gases and air;
Fig. 8 is a longitudinal section of furnace.
"Fig., 9 is a cross section of furnace and gas valve chamber;
Fig. 10 is a horizontal section along V-V Fig. 9.
Fig. 11 is a longitudinal section, through the valve chamber.

page_text: entrance of gaseous fuel and air, and entering the wider zig zag flue C they will
move along, up and down, between the walls B B; in this flue is laid a range of
fire-clay air pipes F F leading to the uptake G for the air, and thus the air is
heated and finally the heating products pass by flue E to the smoke-stack.
The gaseous fuel enters the flue J by passing through the regulating valve and
rises directly, by flues L to be mixed in the inclined flue H before entering the
combustion chamber with the hot air rising by G, baffle plates ab supporting the
mixing of the heated air and the gas. The three ascending flues or uptakes G can
form the continuation of the fire-clay piping F, and the inlined channel H may
also be made of fire clay pipes, especially in cases where forced blast is preferred,
and their ends are then made in tuyere shape.
b) BY OPPOSITE CURRENT OF AIR AND HEATING GASES.
In Fig. 6 and 7, the opposite current of circulation is performed by the combustion
products descending by flue D into a horizontal flat chamber M, dividing into two
branches M and M2 running down at the back and front sides of the furnace, to join
in flue E', from where they pass into the up and down range of flues C C, which
they leave at E¹; the air to be heated enters at a point above E' in clay-pipes F
following the up and down flues and finally rising to the uptakes G leading the hot
air to the flue H and to the baffle-plate 6 of the furnace to be mixed at H with the
generator gas ascending directly through L from flue J.
II. HEATING THE AIR AND THE GENERATOR GASES.
In Fig. 8 to 11 the simultaneous heating of the gaseous fuel and the air for
combustion is performed by sending the air by a range of up and down pipes N,
situated alongside of similar pipes S, in the range of up and down flues O, carrying
in parallel current the hot products of combustion from the furnace.
a set of
Figs. 9, 10 and 11 show an arrangement of the gas main so as to be able to heat
the gaseous fuel or to send it directly without heating to the furnace; in the valve
chamber P Fig. 9, 10 and 11 are two valves Q and Q₁ being operated by
levers and rods and hand wheel U, V, W, X in such a manner, that one is bound
to be shut when the other is open. These valves admit the gaseous fuel either to
Hlue R or R' according to the position of the valves. By R the gas will be
conducted to two ranges of pipes S, in parallel flow with the heating products of
combustion arriving by flue O, and following the up and down range of flues O, as
in Fig. 8 and finally passing away to the smoke-stack at E, the pipes S, being joined
to uptake similarly arranged as G Fig. 8 will deliver the heated gas to the flue H
provided with the baffle-plate b. By flue R¹ when the valve Q₁ is opened, the
gaseous fuel will be admitted directly into uptake flues rising between the gas
pipes S and air pipes N into the flue H without being heated.
Obviously the latter arrangement of simultaneous heating gas and air can also be
carried out with opposite currents or flow of the heating products of combustion in
the flues O and the air and gas in the pipes carried in them. For this purpose only
an intermediate flue like M and front and back down flues M1 and M2 as in
Fig. 6 and 7 would have to be arranged. Also there is no reason obliging to have
the recuperating flue and pipe arrangements described, erected under the furnace as
shown, it could be as well alongside or above it, according to locality.
The cleaning out of flues and pipes is rendered easy by the doors T provided in
the side walls of the recuperator.
. The inclined flues H leading the heated air and the gaseous fuel to the furnace
by the baffle-plate b are formed conic, tuyere-shaped, and they meet just before the
plate 6; running together in a sharp angle, and then they open out suddenly to mix
well before they pass into the combustion chamber through the perforated
diaphragm or baffle plate b.
The products of combustion then, being conducted to flue D by a narrowed

page_text: passage at c, cause a retardation of the flow of burning gas in the furnace, so as to
raise the pressure in the furnace somewhat, which contributes likewise to an excellent
mixture of the gases and air, obliging them to remain a longer time in the furnace
and so cause absolutely complete combustion; in admitting the gas and air in
proper proportion, only completely burned products will leave the furnace.
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 combination with a furnace A for high temperatures an arrangement for
continuous heating, without accumulators of heat, the gaseous fuel and the air
necessary for its combustion, on their way to the combustion chamber, both
simultaneously or the air only, consisting in a set of up and down ways or flues C
for the products of combustion, wherein are disposed a series of fire-proof pipes F
connected at top and bottom by U-shaped pipes to follow the curvatures of the said
flues C, and which series of pipes is connected to the main entrance of air at one
end, and at the other end to the uptake G conducting to the flue H of the furnace;
the products of combustion leaving the furnace A by flues D and flowing either,
as in Fig. 1 directly from D into C, in parallel direction to the air in the pipes, or
also as in Fig. 6, entering the set of up and down flues C, by the channels M
and M', M' and, flowing in a direction opposite to the flow of air in F.
2. In combination with a furnace A, as in Claim 1 the arrangement of heating
the gaseous fuel on its way to the furnace by sending it through similar fire-
proof pipes S as described for the air in Claim 1. connecting these gas pipes S
to the valve chamber fitted with admission valves Q and Q', Fig. 11 and, to direct
the flow of gas by channel R Fig. 9 where the pipes S are connected, in parallel
or in opposite direction to the flow of hot products of combustion following the
series of pipes S and going then by uptake Ġ to the baffle plate in a heated state;
or also; by directing the flow of gas by valve Q' and chanuel R' directly to the
furnace without being heated.
3. In combination with a furnace as in Claims 1 and 2 the arrangement of flues
for the hot products of combustion as in Fig. 9 and 10 so as to receive the pipes
for the air N as well as the pipes for the gaseous fuel Fig. 9 and 10, the pipes N
being connected to the air main, and pipes S being connected to channel R,
Fig. 8, coming from the valve Q for regulation of gaseous fuel, and having the flow
of hot products of combustion circulating through the said flues either in parallel
or in opposite direction to the flow of gas and air in pipes N and S, which latter
lead to the furnace.
4. In combination with a furnace A as in Claims 1, 2 and 3 the arrangement of
the baffle plate in the mixing chamber H formed by the junction of the
pipes G and L at the top of the furnace, which is inclined slightly downwards and
tapering outwards towards the front end, for the purpose of mixing the gas and air
intimately.
5. In combination with a furnace A as in Claims 1, 2 and 3 the narrowing of the
outlet channel for the products of combustion said channel leading at the narrowest
point c into the channel D in order to retard the flow of gases from the combustion
chamber and to cause a certain pressure in the furnace, the whole as illustrated
and for the purpose set forth.
Dated this 31st day of May 1895.
AUGUST DAUBER,
Per Karl J. Mayer,
Agent.