Self Acting Funnel Damper for Marine and other Boilers.
Year: 1893

page_text: Date of Application, 13th May, 1893
Complete Specification Left, 13th Feb., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
Self Acting Funnel Damper for Marine and other Boilers.
I, JOHN ALEXANDER SMITH, of 56 Plantation Street, Glasgow, in the County
of Lanark, North Britain, Marine Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a Self Acting Funnel Damper for Marine and other
Boilers, and has for its object to provide means whereby the steam pressure in the
boiler opens or closes the said damper so as to always keep the pressure in the
boiler equal.
In carrying out my said invention I employ a steam cylinder having the necessary
valve chamber or chambers and ports, also covers, stuffing boxes and other attach-
ments; inside the said cylinder works an ordinary piston the rod of which is
suitably attached by rod, link, lever or levers to the damper. Near the back end
of said cylinder I mount within a valve casing a circular or other valve having a
flat or D shaped exhaust valve and spring attached, as also a weighted spring and
screw arrangement outside the casing. I also mount near the front end of said
cylinder another circular or other shaped valve having an exhaust port or passage
formed in it, as also an inlet port, this valve is also provided outside the casing
with a weighted spring, screw and lever arrangement. The said valve casings are
preferably formed in one so that the steam chamber is between the valves, and the
valve chambers may be provided with liners.
The action of the foregoing is such that, suppose the pressure in the boiler is
desired to be kept at say 160 lbs. pressure the rear or damper closing valve would
be weighted to 160 lbs. and the front or damper opening valve would be weighted
to say about 159 lbs., so that on the pressure in the boiler rising above the
160 lbs. the rear valve would open and allow steam to get into the cylinder behind
the piston and so force it forward so as to shut the damper, and at the same time
the front valve would be pushed forward so as to close the inlet port and open the
exhaust port in front of the piston. On the pressure in the boiler falling below
the 160 lbs. pressure the reverse action to the foregoing will take place.
As a modification, I may employ, in lieu of the front opening valve and its
connections, one or more suitably proportioned dead-weights, which would be
connected to the damper in such a manner as to open it or keep it open when
required. The cylinder in this case only shuts the damper.
My said self-acting arrangement may be mounted either horizontally or
vertically.
Dated this 11th day of Ma 1802
J. Y. JOHNSON,
115, St. Vincent Street. Glasgow, Applicant's Agent.
COMPLETE SPECIFICATION.
Self Acting Funnel Damper for Marine and other Boilers.
I, JOHN ALEXANDER SMITH of 56 Plantation Street, Glasgow, in the County
of Lanark, North Britain, 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 which relates to a Self Acting Funnel Damper for Marine and

page_text: other Boilers has for its object to provide means whereby the steam pressure in the
boiler opens or closes the said damper, in such a manner as to always keep the
pressure in the boiler equal.
But in order that my said invention may be more readily understood and easily
carried into effect, I will proceed to describe the same with reference to the
accompanying drawings.
Figure 1 is a sectional elevation of my said invention and Figure 2 is a similar
view of a modification of the same.
Referring to Figure 1 of the said drawings, I employ a steam cylinder A having
a valve chamber B, and valves C and D, with the ordinary inlet and exhaust
steam ports, covers and stuffing boxes. Inside the said cylinder A works an
ordinary piston E, the rod F of which after passing through the stuffing box a is
provided at its front end with a guide block which works on a guide rod f
mounted in and supported by the bracket/2; the front end of the said piston rod F
is also connected by means of a rod F' and link F2 to the spindle or pivot G of
the damper, in such a manner, that one stroke of the piston will move the
damper through a quarter of a circle as shown by dotted lines. Near the back
end of the cylinder A and within the valve chamber B, I mount a circular or other
valve C having a flat or other shaped exhaust valve or washer and spring c
attached as also a weighted spring and screw arrangement C' outside the casing,
the rod of which passes through the exhaust valve c and bears against the back
of the valve C as shown. Near the front end of the cylinder A and within the
chamber B, I also mount a circular or other shaped valve D, having an exhaust
port or passage d formed in it as also an inlet port d', this valve D is also provided,
outside the chamber B, with a weighted spring, screw and lever arrangement D' as
shown. The arrangement of the said valves C and D is such that the steam space
or chamber b is between them so as to allow the pressure of the steam to actuate
the desired opening or closing valve automatically as hereafter described. The
valve chamber B is preferably provided with brass or other liners & which act as
seats for the valves C and D.
The action of the foregoing is such that, suppose the pressure in the boiler is to
be maintained at say 150 lbs. pressure, the spring arrangement C₁, of the rear or
damper closing valve C, is weighted to the desired pressure, namely 150 lbs. ; the
spring arrangement D', of the front or damper opening valve D, is weighted to
say 149 lbs. and the weights hung on the damper to keep it open in conjunction
with the steam in the cylinder A when the pressure is below 149 lbs. the action is
as follows: As long as the pressure in the boiler is below 149 lbs. the weights
and steam in cylinder A keep the damper open, and on the pressure reaching the
149 lbs. the valve D is moved outwards so as to open the exhaust ports, d and d²
and permit of the steam in front of piston E being exhausted so as to leave the
piston E free to be acted on so as to close the damper by the steam when it rises
to 150 lbs. which is effected by the steam opening the valve C and closing the
exhaust valve c so as to cause the steam to force forward the piston E, and so close
the damper, in which position it remains until the steam in the boiler falls below
the 150 lbs. pressure, the reverse action to the foregoing takes place and the parts
take up the position shown in the drawing and so open the damper.
As a modification I may employ an arrangement as shown in Figure 2 of the
drawings, that is to say, in lieu of the front or damper opening valve and its
connections, I employ one or more suitably proportioned dead weights, which would
be connected to the damper in such a manner as to open it or keep it open when
required. The cylinder A and piston E in this case only come into action when
the damper requires to be shut, that is when the pressure has risen above the
desired amount, the weights on the damper keeping it open as long as the pressure
is below the desired amount.
Figure 2 also shows a modification of the piston and rod, the piston E in this
case being a truncated one, to the rear end of which the rod F is attached.
Either of the foregoing arrangements may be mounted horizontally or vertically.

page_text: 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 :-
1st. The general arrangement, construction and combination of the various parts
constituting the self-acting funnel damper for marine and other boilers, substan-
tially as and for the purposes herein before described and shown in Figure 1, of the
accompanying drawings.
2nd. The self-acting funnel damper, consisting of the cylinder A, weighted
opening valve D and weighted closing valve C, substantially as and for the purposes
hereinbefore described and shown in Figure 1 of the accompanying drawings.
3rd. The general arrangement, construction and combination of the various parts
constituting the self acting funnel damper, substantially as and for the purposes
herein before described and shown in Figure 2 of the accompanying drawings.
4th. The self acting funnel damper consisting of the steam cylinder A, weighted
closing valve C and proportioned dead weights, substantially as herein before
described and shown in Figure 2 of the accompanying drawings."
Dated this 12th day of February 1804
J. Y. JOHNSON,
115, St. Vincent Street, Glasgow, Applicant's Agent.