Improvements in and connected with Apparatus for Preventing Smoke from Boiler and other Furnaces.
Year: 1891

page_text: Date of Application, 30th July, 1891
Complete Specification Left, 30th May, 1892-Accepted, 2nd July, 1892
PROVISIONAL SPECIFICATION.
Improvements in and connected with Apparatus for Preventing
Smoke from Boiler and other Furnaces.
I, WILLIAM CHARLES POPPLEWELL B.Sc. of 1 Princess Street Manchester
in the County of Lancaster, Engineer, do hereby declare the nature of this inven-
tion to be as follows:-
This invention relates to apparatus and devices for preventing smoke from boiler
and other furnaces in which or in combination with which it is necessary or desirable
to cut off or diminish the supply of either air or steam or both air and steam
shortly after stoking, and its object is to provide means whereby the supply of air
or steam may be so cut off or diminished automatically.
I will describe the nature of my invention with reference to means for pre-
venting smoke by the action of a steam jet inducing a current of air into the
furnace. This action should be limited to a period of two or three minutes after
stoking the furnace, but as the supply of steam has at present to be turned on and
off by the stokers, it frequently happens that they turn it on or off either too soon
or too late. By means of my improvements the supply of steam is automatically
cut off at the termination of such a period as the apparatus may be adjusted for,
the adjustment being variable within comparatively wide limits.
The apparatus constructed for controlling the admission of steam or air to the
furnace, as constructed according to my present invention, consists of a cylinder
containing a piston rod adapted to be moved longitudinally by the opening of the
furnace door. The piston rod also carries valves moving over ports through which
steami passes into and out of the apparatus in such a manner as to control the
admission and exit of the steam. A chamber is arranged, preferably in the form
of an annular space around the cylinder, in communication with the steam inlet and
with the under side of the piston, the passage of communication with the under side
of the piston being controlled by an adjustable valve. The piston rod is provided
with a collar or projection limiting its motion in the upward direction, and with a
spiral spring tending to force the piston downwards along its rod upon which it is
otherwise free to slide.
The piston rod is connected with the door of the furnace by a chain and bell-
crank lever or otherwise, so that on the opening of the door the rod is pulled down-
wards thus opening the steam ports in the apparatus and permitting the steam to
find its way through suitable connecting pipes to the steam jet within the furnace.
Immediately upon this action taking place, steam or condensed water finds its way
through the adjustable opening below the piston and forces it upward along its rod
until by direct action or through the intervention of a spring it presses upon the
collar on the piston rod which is thus also compelled to participate in the motion
of the piston and closes the steam ports through which the steam for the jet
passes.
The supply of air to the furnace, independent of that induced by the steam jet,
may be controlled by the movement of the piston rod acting to close a damper or
to remove an obstacle to the closing of the furnace door.
Dated this 29th day of July A.D. 1891.
WILLIAM E. HEYS,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Apparatus for Preventing
Smoke from Boiler and other Furnaces.
I, WILLIAM CHARLES POPPLEWELL B.Sc. of 1 Princess Street Manchester in
the County of Lancaster, Engineer, 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 apparatus and devices for preventing smoke from boiler
and other furnaces in which or in combination with which it is necessary or desirable
to cut off or diminish the supply of either air or steam or both air and steam
shortly after stoking, and its object is to provide means whereby this operation
may be effected automatically.
In the arrangement represented, a supply of air is induced for a period of two or
three minutes ofter stoking by means of a steam jet which is operated by the opening
of the furnace door. At the expiry of the desired period, the supply of steam is
cut off automatically and the current of air induced thereby ceases. In combina-
tion with the apparatus I have also represented an air door above the furnace door
which is automatically opened when the steam jet is opened, and closed when the
action of the jet ceases. This door or damper may or may not be employed, but
where it can be arranged conveniently, I prefer to use it.
Figure 1 is a front elevation of the apparatus as arranged in combination with a
boiler furnace, and
Figure 2 is a side elevation.
Figure 3 is an elevation of the air door and the means for opening and closing
it; and
Figure 4 is a section taken at right angles to Figure 3.
Figure 5 is a longitudinal section of the controlling device.
I will first describe the controlling device illustrated by Figure 5. This consists
of two cylinders A B, in which on the ends of a common hollow rod G, are the two
pistons CD, rigidly connected and thus forming a different piston working respec-
tively in the cylinders. The cylinders in the arrangement shewn are of unequal
diameters but they may be of other relative dimensions than those indicated
according to the fluid pressures employed in them when at work.
One of the
cylinders, B, is placed in communication with a source of fluid pressure which may,
by way of example, be the public water service, or the water space of the boiler;
the other cylinder A is placed in communication with the steam space of the boiler.
It is necessary that the total pressure exerted by the steam on the piston in
cylinder A should be in excess of the fluid pressure exerted upon the piston in
cylinder B, and such that, both the communications being open, both the pistons
(which are rigidly connected) will be driven to the ends of the cylinders opposite
to that in which they are represented. By this motion of the pistons, the fluid
previously contained in the cylinder B will be displaced and I utilise this act of
displacement for the purpose of controlling the duration of the interval between
putting the apparatus in action and the cutting off of the steam and air supply to
the furnace. For this purpose I make the communication from the cylinder to the
source of fluid pressure, through a valve E which may be adjusted by the hand
wheel F. If the valve be wide open, the fluid will be quickly displaced and the
interval will therefore be short, but if the valve be nearly closed, the fluid will
leave the cylinder very slowly, and the interval will be long. In practice this
valve is adjusted so that the interval is from two to three minutes, or such other
period as may be found necessary to admit air after stoking, by means of the
apparatus. If the fluid pressure per square inch in B is less than that in A, the
cylinder B may require to be as large or larger than A, but their relative diameters
are readily calculated for every case.

page_text: Within the hollow piston rod G, there is a valve stem H having a projection or
enlargement I at its inner end, and on its outer end the valve J. This valve may
be made hollow as shewn, and includes the enlarged end K' of the rod K in such a
manner that the end of the rod may be moved to a limited extent in the valve, the
amount of its motion in one direction being limited by the length of the cylindrical
part of the valve, and in the other by a cover or contracted part L. The steam is
admitted at M on one side of the valve, on the other side of which are the
ports N, O; N, leading to the under side of the piston C, and O, leading to the
steam jet and to the door closing device when either or both of these are
employed.
Assuming the pistons to be in the positions represented, it will be obvious that if
the rod K be pulled outwards, the valve J will be opened and steam will be
admitted to the cylinder A, to the jet, and to the door opening device simul-
taneously. The valve remains in its open position until the pistons have travelled
so far that the projections P in the hollow piston rod come into contact with
the enlarged end of the valve rod; after which, the continuation of the move-
ment of the pistons closes the valve, thus shutting off the admission of steam,
whereupon the motion of the pistons ceases, the pressure in B becomes greater
than that in A, and the pistons are returned to their original positions.
The rod K is moved outwards so as to open the valve, by the act of opening
the furnace door. To effect this a fixing is attached to the furnace door R
(Fig. 1) and is connected so as to produce the desired motion, by means of a
crank or angular lever or by other suitable mechanism which will communicate
the motion to the outer end of the rod. On the closing of the door the rod
is pushed back or it may be returned by the spring K" but as its enlarged end
slides freely within the cylindrical part of the valve body, this motion does not close
the valve.
When I employ a door or damper which is to be automatically opened and
closed for the admission of air, prefer to adopt the arrangement illustrated
by Figures 3 and 4. S is the door pivoted at T T¹ and having on one of its
pivots the crank and crank pin U or equivalent connecting link-work, secured
to the lower end of the piston rod V of the piston W included in the cylinder X. A
spiral spring is included in the cylinder for the purpose of returning the piston when
the supply of steam is cut off. On the opening of the furnace door, steam is admitted
to the upper side of the piston W forcing it and its rod downwards, which motion
opens the door S.
When the supply of steam is cut off by the closing of the valve,
the action of the spring, to which may be added the weight of part of the door,
returns the piston and closes the door. If preferred the spiral spring may be
omitted, and its function may be performed by a counterweight on the door or
connected with the piston rod.
Y is the steam jet and Z is the air trunk within the furnace.
of the construction at present in use.
Both these may be
Any condensed water collecting in the cylinders A and X may be removed
through suitable openings or drain cocks.
Immediately upon the opening of the furnace door steam is admitted to the
steam jet, to the cylinder A, and to the cylinder X. Thereupon the air is induced
into the furnace by the action of the jet, and the door S opened for the free
admission of air. After the determined period, the supply of steam is auto-
matically cut off, the steam jet ceases to act, and the door is closed gradually.
In some cases I may omit either the steam jet or the door S with its controlling
device, and for the door I may substitute a louvre or damper of any suitable and
convenient construction.
I desire it to be understood that I do not limit myself to the precise con-
struction and arrangement of the details represented by the drawings as these
may be considerably modified. For example the piston rod G and the rod K
may be one single rod or the one be a continuation of the other, but this
arrangement is less suitable than that described. Also the pressure for returning

page_text: the pistons CD may be obtained from the adjustable spring, in which case the
second cylinder would be omitted and only one piston C would be required.
Further, any suitable arrangement for the admission of steam to the cylinder A
may be employed, other than that illustrated. If the apparatus be arranged
vertically, the piston rod G may be employed to open and close the door S directly,
but I prefer the arrangement illustrated in which the rod is divided into the
parts G, K as putting less work upon the rod G.
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. An apparatus for controlling the admission of air or of air and steam to boiler
and other furnaces, constructed arranged and operated substantially as hereinbefore
described.
2. In an apparatus for controlling the admission of air or air and steam to boiler
and other furnaces, the combination and arrangement with the furnace door, of a
piston and cylinder, a valve admitting steam to the cylinder and controlled by the
opening of the door, a rod actuating the valve and actuated by the door, an adjusting
device for producing a variable counter pressure against the piston, and means for
communicating the motion of the door to the rod; substantially as hereinbefore
described with reference to the accompanying drawings.
Dated this 28th day of May A.D. 1892.
WILLIAM E. HEYS,
Agent for the Applicant.