Improvements in and relating to Air and Gas Valves for Furnaces.
Year: 1899

page_text: Date of Application, 17th Oct., 1899-Accepted, 2nd Dec., 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Air and Gas Valves for Furnaces.
We, PATRICK MEEHAN and ROBERT GRAY, both of Lowellville, County of
Mahoning, and State of Ohio, United States of America, Manufacturers, do here-
by 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:
Our invention relates to gas and air valves for feeding both gas and air to
furnaces, such as boiler furnaces, hot blast stoves, or like structures, its object
being to provide a simple and efficient valve which will provide for the feeding of
both gas and air in proper proportions to support combustion by a single move-
ment of the lever, so that it can be controlled by any workman.
It consists, generally stated, in a combined gas and air valve having a horizontal
chamber provided with an air port and a gas supply pipe opening by
a port into this chamber, the length of the air port being in pro-
portion to the gas port, according to the proportion of air and gas to be
admitted, and a slide valve enclosed within the chamber and sliding over the gas
port and adapted in its movement, to control, that is, to open and close both the
gas and the air ports simultaneously, so that the movement of the valve, as soon
as any gas is admitted to the furnace a proper proportion of air to support the
combustion will also be admitted thereto, and as the valve openings are increased
or diminished the proper size of port for feeding the proper proportions of air
and gas will be maintained. It also consists in other improvements, such for
example as the employment of a valve of smaller size that the interior of the
chamber and having an outlet opening at the end toward the furnace, so that the
air can pass over the top and sides of the valve and mingle with the gas escaping
at such outlet, so as to cause the proper mingling of the air and gas as they enter
the furnace chamber. It also consists in means for locking or holding down such
valve as against back pressure within the chamber, which is found in some cases
necessary, especially in hot blast stoves.
To enable others skilled in the art to make and use our invention we will des-
cribe the same more fully, referring to the accompanying drawings in which-
Figure 1 is a vertical section of the invention as applied to a furnace for hot
blast stoves;
Figure 2 is a horizontal section on the line 2-2 Figure 1, indicating the con-
struction of the parts and showing the preferred size of air and gas inlets;
Figure 3 is a vertical cross section on the line 3-3 Figure 1;
Figure 4 is a vertical section showing another form of the valve applied to a
boiler furnace;
Figure 5 is a like view showing still another form of valve embodying the
invention, and
Figure 6 is a detail of a modified valve seat.
Like letters of reference indicate like parts in each of the figures of the
drawings.
While the invention is illustrated in different forms, the general principle
is the same in all, namely, the employment of a chamber having both air and

page_text: gas ports, the air port being proportioned to the gas port, in accordance with
the desired proportions of air and gas to be fed to the fire chamber, the valve
sliding within this chamber over the gas port and in its movement covering or
uncovering both air and gas ports. In the preferred construction shown in
Figures 1, 2 and 3, the burner is attached to the furnace A, which can be of any
construction, either that which is shown, which is the base of a hot blast stove.
or a boiler furnace, as illustrated in Figure 4, or other furnace to which the same
is applicable. The furnace chamber has the entrance port a, in line with the
valve chamber b, which is preferably formed, as shown, in a horizontal position.
This chamber is usually formed of a casting corresponding in width to the port a,
or adapted, as shown in Figure 4, to fit said port neatly, and the casting having
the top wall, side walls, bottom wall, and end wall 64. The bottom
wall is generally formed with a flat upper surface upon which the valve crests
and over which it travels when in use, though, as shown in Figure 6, a dove-
tailed connection y may be formed. between the valve chamber casting and the
valve to hold it down in place. For general purposes, however, the weight of the
valve is sufficient for this purpose, and it need only be held down when it is
desired to absolutely lock the valve, such for example, as in hot blast stoves
where the blast is being passed through the furnace, in which case the valve may
bé locked down by means of the hand bolt 1 pressing on the top wall of the
valve and binding it down upon the gas port, or the valve may be put in a vertical
position when necessary. In the bottom of the valve chamber are the gas port c
and the air port f, the gas port e leading up from the gas pipe el, carrying the
gas from any desired source, either from the blast furnace, or from natural or
artificial gas supply pipes. The air port f opens directly to the atmosphere. As
seen in Figure 2, both gas and air ports are rectangular in shape; these may be
varied to suit circumstances, the air port being in proportion to length of the
gas port, and the length of these ports can be varied according to the desired sup-
ply of air to support combustion of the gas admitted, which of course varies
according to the gas used, but is always of greater volume than the gas. The
ports are preferably made of about the same width, and therefore as they are un-
covered by the movement of the valve they maintain practically the same pro-
portional size of air inlet and gas inlet, no matter in what position the valve is
placed. The shape of the gas valve is made clear in the different drawings, the
valve having the top wall c', side walls, and having the end wall The
entrance port is formed at the rear end of the valve body, close to the back
wall, the valve having the bottom wall which travels over the port c and
closes the same, which wall extends out to the mouth g of the valve. In order
to control the air port f the valve has the tail piece h, of sufficient width to
cover the air port, which extends over said port and acts to open or close the
same as the valve is moved. It will be noticed that between the top wall of
the valve chamber and the top wall of the valve, and between the side walls
of the chamber and the valve that full space is provided for the flow of the air
entering from the air port f over the top of the valve body, and that there is no
opportunity for the mixing of the gas and air until they pass the front end of
the valve where the gas escaping through the mouth g can mingle with the air
passing over the valve, when the gas being lighter than the air will mingle there-
with and the mingled gas and air will pass into the furnace chamber A. For
the purpose of moving the valve, any suitable device may be employed, for
example, where the valve is employed with a hot blast stove and the parts are
subjected to pressure, the valve rod m may extend out through a stuffing box m'
in the rear wall of the valve chamber, at which point it can connect onto any
suitable lever, screw or like device for moving the valve.
In the use of our invention as embodied in the construction shown in Figures 1
and 3, and when used with a hot blast stove, when the furnace is to be lighted
the valve is moved forward by its rod m, permitting the entrance of gas and air
through the ports e and ƒ in the desired proportion, and the gas is ignited and

page_text: burns within the furnace chamber A, and the heat in said chamber is regulated
by the slide valve as desired. The gas and air mingle at the mouth of the valve,
as above described, and burn in said chamber, being under full control of the
workmen by the simple sliding of the single valve. As the valve is slipped for-
ward it opens or uncovers both air and gas ports, and on account of the difference
in size of the two ports, proper portions of gas and air are fed to the chamber.
When it is desired to carry air through the hot blast stove, the gas and air supply
are cut off by the drawing of the valve back so as to close the ports c and f, and
in order to prevent the escape of air from the hot blast by the entrance of gas,
if its pressure should be higher than that of the air, we prefer to screw down the
hand screw D, forcing the valve into close contact with the bottom of the valve
chamber and so positively closing the valve ports. The valve can be quickly
opened by the running up of the screw D and the movement of the valve in its
chamber, as above described.
The construction shown in Figure 4 of the drawing is practically the same as
that described, except that the air port is maile in the rear wall and this port
is closed by the rear wall of the sliding valve 2, and the lever is connected
directly to a strap, which is connected to the valve body through said port »,
and the valve can therefore be easily moved without the necessity of the employ-
ment of a stuffing box. The construction shown in Figure 5 is also the same as
those above described, except that the valve is opened by a backward movement
instead of a forward movement, and so doing forms an air port at the end of the
valve chamber. For example the valve chamber s is open at the rear end, and
the valve has projecting upwardly from it the plate or extension t¹, which closes
the space above the valve body, fitting against the open end of the valve cham-
The valve has also the bottom wall covering the gas port and the
port which by the backward movement of the valve body is drawn over the
gas port and so admits gas to the valve; the valve body having also the
mouth, at which point the air entering at the open end of the valve chamber
mingles with the gas entering from the gas port into the valve. This valve
can be operated in the same way as the other valves by a simple lever or like
connection, and it gives the same control both of gas and air ports, differing only
ber s.
in the direction in which it is moved.
In either form of the valve employed, a very simple valve is provided and one
which on account of its simplicity is not liable to injury by the heat of the fur-
nace, while by a simple movement of the single valve in either direction the
control of both gas and air in proper proportions for combustion is provided.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:
1. A combined air and gas valve having a valve chamber provided with air
and gas ports, and a slide valve enclosed within the valve chamber and opening
toward the furnace chamber, whereby there is space at top and sides of said valve
for the passage of air, said valve sliding over the gas port and adapted in its move-
ment to control the air port, substantially as set forth.
2. A combined air and gas valve having a valve chamber provided with gas
and air ports, the air port being proportioned to length of the gas port, and a
slide valve within said chamber having a body of smaller size than the chamber,
said valve sliding over the gas port and controlling both gas and air ports in
its movement, substantially as set forth.
3. A combined gas and air valve having a valve chamber provided with an
air port, and with a gas port opening through the base thereof, and having a
slide valve of smaller size than the chamber, and enclosed within and contacting
with the base thereof, said valve having closed top, side and end walls and a
mouth opening toward the furnace chamber, and having a port controlling the
gas entrance, substantially as set forth.

page_text: 4. A combined gas and air valve having a valve chamber provided with gas
and air ports in the base thereof, the air port being proportioned to the gas port.
and a slide valve enclosed within and sliding over the base of the chamber, said
valve having a solid top, side and rear walls, a port in its base for the entrance
of gas, and an open mouth at its forward end, and having a tail piece extending
over the air port, substantially as set forth.
5. A combined air and gas valve having a valve chamber provided with gas
and air ports and a slide valve enclosed therein, and contacting with the base
thereof and sliding over the gas port and controlling the air port, said valve
having solid top, side and end walls, and an open mouth toward the furnace
and a hand screw passing through the top of the valve chamber and contacting
with the valve body, substantially as set forth.
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111
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11900
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.