Boiler Furnaces.
Year: 1885

page_text: Boiler Furnaces.
I, JOHN AULD, of the firm of David Auld and Sons Whitevale Foundry,
Rochester Street, Glasgow, Lanarkshire, Engineer, do hereby declare the nature
of my invention for "IMPROVED APPARATUS FOR ACTUATING THE DAMPERS OF
STEAM BOILER FURNACES, to be as follows:-
My invention has reference to improved reciprocating apparatus for auto-
matically closing and opening the flue dampers of steam boiler furnaces according
as the steam pressure rises above or falls below the normal pressure which the
boilers are regulated to maintain; which improved apparatus will be quite as
efficient in its action, and yet be more simple, durable, and inexpensive than such
automatic damper-actuating apparatus have been heretofore.
My said improved reciprocating apparatus for automatically actuating the
dampers of steam boiler furnaces consists in its simplest construction, or general
arrangement of its parts as follows:-Of an outer hollow stationary vertical case or
cylinder, with close bottom and open at top, and fitted with a deep hollow inverted
cup reciprocating piston close at top but open at lower end, only a little less in
diameter than the interior of the outer cylinder in which it will thus work freely.
The upper close end of this piston would preferably have a slightly raised chamber
or domed part in the centre open into the interior but close on top, which would
be connected by a piston-rod guided at top with a connecting rod or a chain, for
transmitting the power and motion to work the connecting lever of damper, or
through a segmental lever or large pulley (according as a connecting rod or chain
is attached to the piston rod) and carried on brackets secured to the top of the
outer cylinder, which motion might be further transmitted by extra rods and
levers or chains and pulleys when the apparatus required these to actuate the
dampers at a distance from it. The steam from the boiler to actuate the hollow
piston would be carried by a vertical pipe through the centre of the close bottom
of the outer cylinder, and up through the centre of the open hollow piston into the
small dome in the close top; where it would escape at the open end of steam pipe
and fill the upper close part of the hollow piston and by its pressure therein raise
the piston. To prevent condensation in the steam pipe it would have a hollow
stand pipe all round it projecting up from the bottom of the outer vessel, which
Den 017

page_text: would be filled with water to near the top of the hollow piston, to form a close
water packing between the cylinder and piston, and form a resisting medium or
surface for the steam to act on the inside of the piston to raise it, when the steam
was admitted as stated. An overflow branch would be formed through the side
of the outer cylinder some distance above the top of the piston and at the height
to which the water would require to rise in the cylinder when working properly,
so as only to draw off the accumulation and loss caused by condensation of the
steam in contact with the water. The piston would be in its lowest position in
the cylinder when the damper connected to it was up or open; and so as to be
lowered or swivelled shut when the steam raised the piston by its pressure and
displacement of the water out of the piston, but which when there was no steam
'acting would lower and open the damper by the weight of the piston or by
counter-balance weights. Instead of using the said loose deep water-jointed piston
and cylinder, an ordinary bored cylinder might be used, fitted with an ordinary
turned or packed piston, both of which would be much shorter than required with
the hollow water piston, and the steam might be admitted by a side branch at the
bottom of the cylinder and the small air or drawing off branch with tap at the
other. Or otherwise, instead of making the steam act direct under the piston as
just described, the steam might be made to enter at the top of a close water vessel
and force this through a pipe from its bottom end led into the bottom of the
cylinder and piston so as to force it up, all as before stated; but in all of these
adaptations or applications, the weight of the piston or counterweights would bring
these single acting reciprocating pistons always back to their lower normal position
to open the damper when the steam was below the normal pressure in the boiler
and not admitted to the cylinder under the piston; in the latter example the
piston in returning would force the water back into the water chamber, which in
this case would preferably be fitted at the level of the water in the supply water
displacing vessel described with a regulated discharge branch.
This improved apparatus is worked automatically by the steam from the boilers,
whose damper it regulates as before explained, but allowed to escape above the
normal regulated pressure to the steam pipe of this apparatus to actuate it all as
described, through any of the well-known safety valves, or other steam pressure
regulating piston or diaphragm valves with their closed-in valve chests which would
either allow the actual escaping steam from the valve to pass direct, or open a
smaller pass valve which would allow the live pressure steam to pass direct to the
steam pipe of the apparatus and work it; in the latter case a much smaller
working piston and cylinder would be required in.the apparatus than in the former
application.

page_text: Improved Apparatus for Actuating the Dampers of Steam
Boiler Furnaces.
I, JOHN AULD, of 91 Rochester Street, Glasgow, Lanarkshire, 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 in writing reference being had to the accompanying Sheet of Drawings
and to the reference letters and nunerals marked thereon, that is to say :-
My invention has reference to improved reciprocating apparatus for automatically
closing and opening the flue dampers of steam boiler furnaces according as the
steam pressure rises above or falls below the normal pressure which the boilers are
regulated to maintain; which improved apparatus will be quite as efficient in its
action and yet be more simple, durable and inexpensive than such automatic
damper-actuating apparatus have been heretofore.
My invention is illustrated by the accompanying Drawings in which Figures 1
and 2 are sectional elevations of two modifications of my improved apparatus
as used with the water piston or float arrangement; and Figures 3 and 4 are
sectional elevations of two different modifications of my apparatus with close
working cylinders and pistons, which are actuated directly by the pressure of steam
admitted to them; and Figure 5 is a sectional elevation with close cylinder and
piston, having water forced into the cylinder to raise the piston by the action of
the steam from the boiler, each arrangement being modified improvements of my
apparatus for automatically opening and closing the dampers of steam boiler
furnaces in accordance with my invention.
Referring to Figures 1 and 2 my said improved reciprocating apparatus for
automatically actuating the dampers, of steam boiler furnaces, consists in its
simplest construction, or general arrangement of its parts, as follows:-Of an
outer hollow stationary vertical case or cylinder A, with close bottom A¹, and open
at top A, and fitted with a deep hollow inverted cup or float reciprocating
piston B, close at top B¹, but open at lower end B2, somewhat less in diameter than
the interior of the outer cylinder A, in which it will thus work freely. The upper
close end of this piston B, would preferably have a slightly raised chamber or
doned part B in the centre open down into the interior, but close ou top, and
which would be connected by a rod c, or chain c¹ connected at the top to a segunental
lever C, C¹, carried on a bracket C2, secured to the flange at the top A³ of the outer
cylinder A. The lever C, C', may be counter-weighted to work the damper direct
by the motion communicated by the falling or raising of the piston B'; or the
motion given to the lever C, C, might be further transmitted by extra rods and
counter loaded levers, or chains and pulleys at the damper end, but not shown in
the Drawings being well understood, when this apparatus required these to actuate
the damper at a distance from it. The steam from the boiler pressure regulator
for the purpose to actuate the hollow piston B, would he carried by a vertical
pipe b up through the centre of the open hollow piston B, into the small dome B¹¹
in the close top B', where it would escape at the open end 6¹ of steam pipe 6 and
fill the upper close part of the hollow piston B and by its pressure therein raise the
piston B. To prevent condensation in the steam pipe it would have a hollow
b

page_text: stand pipe a all round it projecting up from the bottom A¹ of the outer vessel A,
which would be filled with water W to near the top B¹ of the hollow piston B, to
form a close water lute or packing between the cylinder A. and piston B, and form
a resisting medium or surface for the steam to act on the inside of the piston B to
raise it, when the steam was admitted as stated. An overflow branch a³, would be
formed through the side A of the outer cylinder A some distance above the top of
the piston B. At the height to which the water W would require to rise in the
cylinder A when set to working properly at the adjusted steam pressure required
to work the damper, and so as only to draw off the accumulation and loss of water
caused by condensation of the steam in contact with the water W.
To prevent the condensation of the steam on the top of the water, a disc a¹ may
be formed or fitted at the top of the case pipe a for preventing the water cooling
the steam pipe b; and a small tube 611 with controlling tap would be fitted on the
top of piston B, to allow of a very small escape of air and steam to prevent air
accumulating in the upper close part above the water and ensure the working of
the piston B, when ever the steam was admitted thereto by the tube b, connected
to the escape branch 63, of the weight or spring loaded valve e¹, regulated to suit
the pressure desired to be maintained in the steam boiler and that required to
work the piston B. The regulated escape valve chest e is fitted on the steam
chest E which is connected with steam pipes direct from the boiler by the
branch E. Figure 2, is slightly modified from of figure 1, in so far that the
working water part of the cylinder A, and the internal float piston B are made
short just sufficient for the motion of the piston B to move the lever C, C and
damper connected to it by a chain or rod at c; and the upper part contracted by
a cover and a small stand pipe A" open at top. In this example the steam chest E
is dispensed with, and the steam from the boiler is admitted by a tube at E', to
the lower part of the escape regulating valve chest e direct, the valve e' of which
is loaded to suit the pressure of steam desired to be maintained in the boiler, and
the pressure excess above that allowed to escape at the valve e¹ into the valve
chest e acting down the tube ell, will pass up the tube b connected there with and
fill the space in the upper part of the piston B and act all as explained in relation
to figure 1. The dip syphon or trap pipe e² allows the water of condensation to
flow off by the branch es to maintain the normal level of the water in the cylinder
and piston A, B, and flow off by the branch e' in the outer over flow of the trap
which maintains a working pressure equal to work the damper, and when a
greater pressure euters the steam valve chest e the valve e¹ rises so high that it
opens the upper safety or escape valve E2 and lets off the steam to the atmosphere.
The piston B, would be in its lowest position in the cylinder A when the damper
connected to it by the lever C, C and rod or chain c³, was up or open, and so as to
be lowerd, or swivelled shut, by the weight of the damper when the steam raised
the piston by its pressure and displacement of the water out of the interior of the
piston B, but which when there was no steam acting would lower and open the
damper by the weight of the piston or by counter balance weights on the levers.
Referring to Figures 3 and 4 instead of using the said loose water jointed
cylinder and piston A, B, (shown in Figures 1 and 2) an ordinary bored cylinder A
is used, fitted with an ordinary turned or packed piston B, both of which might be
much shorter than required with the former hollow float piston, and the steam
might be admitted by a side branch and pipe at b in the bottom of the cylinder A,
and a small air or drawing off branch 6" with regulating tap is fitted at the
other side.
In both of these arrangements of my improvements, the cylinders A, have
covers As on them and an escape for the air on top of pistons B. The rods c of the
pistons are guided in holes bored in the covers A³, and have their upper ends out-
side the covers jointed by short connecting rods or links c¹ to the horizontal arm C
of the bell crank lever C, C for working the damper, carried on a bracket
standard 2 bolted to the cover A³, the vertical arm C of this lever working the
damper by the rod e in an equivalent manner to that described in reference to the

page_text: former figures. Figure 3 is for working with a low pressure of steam, and has
therefore a larger cylinder A and piston B which is loaded inside the cylinder at B³,
to bring it back to the normal position at bottom of cylinder A when the pressure
of steam is low and not acting under the piston, so as to open the flue damper or
dampers, when it is a range of boilers; an adjusting weight being mounted
outside the cylinder on the arm C of the damper actuating lever C, C¹. The
regulating steam valve chest e is here bolted to the top A² of the cylinder A at one
side, and has a close cover E" steam tight on it. The steam is admitted to this
valve chamber e, from the steam. boiler, through the branch E¹, and the valve e¹
above it, and its spindle is continued up to the top of the chest where it is guided
centrally and loaded with weights at E³. The escaping steam from this regulating
valve chest and valve e, e¹, is led by the tube b to the bottom of the cylinder A
under the piston B, to act all as before stated. The arrangement in figure 4, is for
being worked by high pressure steam, so that the cylinder and piston A, B, are here
made small, and have the counter weights B³, mounted on the upper end el, and
continuation of the piston rod c, outside the cylinder cover A³. In this modification
for the use of high pressure steam a small inverted valve e¹ is mounted at the upper
end of the valve chest e, and lets the escaping steam pass out at the top branch e²,
connected to the pipe b, leading the steam to the bottom of the cylinder A (as in
figure 3). The valve e¹, bas a long pendant stem e¹¹, projecting down within a
lower trunk part of the valve chest e, leading into a semi-domed close chamber
fitted with a disc regulating pressure valve f, to which the stem e¹¹, is attached
below; the disc valve having a socket plunger f secured to it outside the valve
chest, to which is mounted a strong helical re-acting pressure spring f" mounted
within the securing side rods and cross head f, with cap and regulating screw f³,
at lower end of spring. The high pressure steam from the boiler entering the valve
chest e, by the branch E, acts on the large diaphragm valve f below, against the
power of the spring f¹¹ outside, and opens the small valve el at top leading to the
pipes e, b, and bottom of cylinder A, when the pressure in the boiler is higher than
desired or than regulated by this valve arrangement. A good arrangement is shown
in figure 3, of drawing off pipe D, connected at the top D¹ to the upper end of the
cylinder A, to allow of the escape of the air therefrom, through the branch D" near
the lower part of the pipe D. The lower end of this pipe is connected direct with
a screw valve chamber D, leading into the lower end of the cylinder, so as to draw
off the water of condensation formed or collected there through the valve D³ of this
chamber D2, by the branch pipe D¹¹.
Referring to Figure 5,-instead of making the steam act direct under the piston B
as described in reference to figures 3 and 4,-the steam in this arrangement is made
to enter at the top branch g, of a close water vessel G, and force the water down
through the pipe g¹ at its bottom end into the lower end of the cylinder A, below
the piston B, so as to force it up as before described in reference to the other
figures, by the escaping pressure of steam, in the boiler, above the regulated
pressure, which would be admitted by the branch g, to the water acting vessel G.
In all these adaptations of my improvements the piston or counter weights B³ on
it, or on some of the levers directly connected to it, would bring these single acting
reciprocating pistons B always back to their lowest normal position to open the
damper connected to each, when the steam was below the normal pressure of the
steam within the boiler arranged for, and not admitted to the cylinder under
the piston. In this last arrangement figure 5, the piston rode outside the cylinder
cover A², is shown connected to a toothed rack d, with anti-friction pulley behind,
and working into a pinion d¹, on the spindle of a chain wheel d, one end d³ of the
chain being made to work the flue damper direct, or passed over guide pulleys to
work this when at some distance from the apparatus, the other end d', of the chain
on the other side of the chain wheel d² would have a counter weight c², on it to
balance the weight of the damper, and also turn the pinion d', to press down the
piston B, and cause it, on the retorn down stroke to press out the water and return
it always into the working water chamber G again. This chamber G, would be

page_text: fitted preferably at the normal level of the water in it, (as shown), with a water
regulating discharge vessel G¹, with drain cock at G².
In all these arrangements shown in figures 1 to 5, the same respective alphabetical
letters indicate like parts in all the figures, and the arrows on the ducts indicate the
direction of the action of the fluids as against the counter weights which act in the
opposite direction.
My improved apparatus as described in reference to these several figures, is
worked automatically by the steam from the boilers, whose damper it regulates as
before explained, but allowed to escape only at a little above the normal regulated
pressure to the steam pipe b of my said apparatus to actuate it all as described,
through any of the steam pressure valve regulating arrangements shown and
described, or of any other of the well-known safety valves, or other steam pressure
regulating piston or diaphragm valves with their closed-in valve chests, which
would either allow the actual escaping steam from the valve, to pass direct, or open
a smaller pass valve which would allow sufficient live pressure steam to pass direct
to the said steam pipes of the apparatus and work it; in this latter case a much
smaller working piston and cylinder would be required in the apparatus than in
the former application with only the low pressure escaping steam.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The general arrangement and combination of the parts of single acting
reciprocating piston apparatus for actuating the flue dampers of steam boiler
furnaces, primarily actuated by the pressure of steam above the arranged normal
pressure in the boiler, whose furnace dampers they are to work, all substantially
as herein described in reference to and shown in the several Figures of the accom-
panying Sheet of Drawings.
2. In an apparatus for actuating the dampers of steam boiler furnaces, the use
of a single acting reciprocating hollow float piston, or of an ordinary solid or packed
piston, actuated primarily by the pressure of steam above the arranged normal
pressure in the boiler whose furnace damper it is to actuate, substantially as herein
described in reference to and shown in the accompanying Sheet of Drawings.
3. In an apparatus for actuating the dampers of steam boiler furnaces, the com-
bination of a single acting cylinder and working water vessel, primarily actuated
by the pressure of steam above the arranged normal pressure in the boiler whose
furnace dampers it is to actuate, substantially as herein described in reference to
and shown in Figure 5, of the accompanying Sheet of Drawings.
4. The construction or combination of the parts of steam valve chests or regu-
lators, actuated by the steam pressure above the arranged normal pressure in the
boilers, and for supplying steam either of low pressure or high pressure, for
primarily actuating the mechanical apparatus for working the furnace dampers of
such boilers, substantially as herein described and shown in the accompanying
Sheet of Drawings.