IMPROVEMENTS IN APPARATUS FOR PREVENTING THE ESCAPE OF SPARKS FROM SMOKE STACKS OR CHIMNEYS
Year: 1872

page_text: LETTERS PATENT to Edmund Edwards, of the Firm of Edwards and
Co., 38, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Patent Agents and Engineers, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR PREVENTING THE ESCAPE OF SPARKS
FROM SMOKE STACKS OR CHIMNEYS."-A communication from abroad by
William M Kelvy Thornton, of Saint Louis, in the County of Saint
COMPLETE SPECIFICATION filed by the said Edmund Edwards at the
Office of the Commissioners of Patents, with his Petition and Decla-
ration, on the 29th June 1872, pursuant to the 9th Section of the
Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
EDWARDS, of the Firm of Edwards and Co., 38, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agents and
Engineers, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
APPARATUS FOR PREVENTING THE ESCAPE OF SPARKS FROM SMOKE STACKS OR

page_text: CHIMNEYS," and have petitioned Her Majesty to grant unto me, my
executors, administrators, and assigns, Her Royal Letters Patent for the
same, and have made solemn Declaration that the said Invention has
been communicated to me from abroad by William McKelvy Thornton,
of Saint Louis, in the County of Saint Louis, and State of Missouri,
United States of America.
NOW KNOW YE, that I, the said Edmund Edwards, 'do hereby declare
that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of the said Invention, and.
in what manner the same is to be performed, in and by the following
statement and accompanying Drawing:-
This Invention is designed for preventing sparks which rise from the
caps or upper ends of smoke stacks from escaping into the air.
In carrying out this Invention I conduct the smoke and sparks as
they leave the smoke stack or chimney through a close cap which is
arranged on the top of this stack, and in which are arranged a scries
of deflecting plates and an adjustable draught regulating valve. From
this cap the sparks are directed downward and backward into a reservoir
which is covered by a wire netting and in which the sparks are trapped
and collected as will be more fully explained herein-after.
In the accompanying Drawing Figure 1 is a section taken vertically
and longitudinally through the centre of the spark arrestor applied to
the smoke stack or chimney of a locomotive engine; Figure 2 is a section
through Figure 1 taken in the horizontal plane indicated by the dotted
lincs X,
X.
A represents part of the boiler shell of a locomotive engine, and B is
a smoke stack rising therefrom. This stack may be of the usual height
for locomotives, or it may be of greater or less height. The upper end
of the stack B is slightly expanded in diameter and has fixed upon it a
cap C, the front, sides, and top of which are closed, but the rear portion
is open and communicates with a reservoir G at or near the upper
end thereof. The width of the cap C need not be greater than the
diameter of the stack B, but the length thereof is somewhat greater, so
that the sparks will be conducted backward over a bottom plate N and
valve E a short distance before they are directed down into the said
reservoir.
Between the top of the smoke stack and the top of the cap C are a
number of deflectors J which extend transversely across the cap and are

page_text: secured by their ends to horizontal side plates, which latter rest upon
ledges j. The plates J are curved and inclined backward as shewn in
Figure 1, so that the sparks after leaving the upper end of the stack will
be directed backward. Above the deflecting plates J and secured to
the top plate of the cap C inside of this cap are two curved deflectors
a, a', the latter one of which a¹ keeps the sparks out of the extreme
front corner of the cap C, while the deflector a, which curves backward
and downward in rear of the deflector J, directs the sparks downward
into the reservoir G, as indicated by the course of the arrows.
Just over the bottom extension N is a valve or false bottom E which
is hinged in front and held down upon the end of an adjusting screw f
by means of a spring c. The screw is tapped through a nut f' and
extends freely through the bottom plate N. It is used for raising the
rear end of the valve E when it is desired to contract the outlet from
the cap C, and sharpen or intensify the draught. By means of this
adjustable valve the draught can be increased or diminished and
regulated to a nicety.
The cap C opens into an inverted conical chamber which is circular
in horizontal section, and which is secured on the top of the reservoir G.
The upper end of this conical chamber is contracted somewhat and is
covered by a wire gauze or netting h. The corners of this chamber are
not acute or angular, but are rounded as shewn at i so as to prevent
temporary accumulation of sparks at this point. The rear portion of
the cone is cut away, and so also is its front upper portion, and the
edges of the said portions are rivetted to the body of the reservoir G, as
shewn in Figure 1. This leaves a head on the reservoir and at the same
time leaves an inclined deflector m. The body of the reservoir is
elliptical in horizontal section, the longest axis of the ellipse extending
fore and aft (from the front to the back of the apparatus), and this
reservoir, which is composed of two sheets G¹, G³, is secured fast upon
the boiler shell by means of a suitable saddle as shewn in Figure 1.
To the rear termination of the bottom plate N a wire netting shield 9 is
secured, which is of a segmental form and which inclines downward over
the inclined deflector m. This shield serves a very important purpose
in the reservoir as it prevents the sparks which are directed downwards
beneath it from rising again above it. It being perforated allows a
draught from below through it which induces many of the sparks to
pass over from the rear to the front of the reservoir, where they fall
upon the deflector m and thence descend to the bottom of the reservoir.

page_text: The sparks which cross directly over to the back of the reservoir from
the cap C strike against one or more curved deflectors S, shewn in
Figure 1, which not only direct those sparks downward and somewhat
forward but they also shield the cone and reservoir plate. There is no
draught from the bottom of the reservoir upward as the bottom of the
reservoir is closed, but there will be more or less of an eddy therein,
the tendency of which is to direct the sparks forward and upward, but
by means of the shield y and the deflector m the sparks will be trapped
in the reservoir below the said parts and the cinders and dust may be
removed therefrom from time to time through outlets Z.
Having now described this Invention, and the manner in which it is
to be performed, I claim,—
First. The curved deflectors J enclosed in the cap C on the top of
the smoke stack, which cap communicates behind with a reservoir G,
substantially as described.
Second. The deflectors a, a, arranged above the deflectors J in the
cap C, substantially as described.
Third. The adjustable valve E in combination with the cap C and
reservoir G, substantially as described.
Fourth. The reservoir G arranged in rear of a close cap C on the 1
top of the stack B, and covered with wire netting m, substantially as
described.
Fifth. The wire netting shield arranged in the reservoir G, sub-
stantially as described.
Sixth. The imperforated deflector m arranged below the shield g,
substantially as described.
Seventh. The deflectors S arranged inside of the reservoir, substantially
as described.
In witness whereof, I, the said Edmund Edwards, have hereunto set
my hand and scal, this Twenty-ninth day of June, in the year
of our Lord One thousand eight hundred and seventy-two.