Improvements in Steam Boilers.
Year: 1889

page_text: Date of Application, 23rd July, 1889
Complete Specification Left, 31st Mar., 1890-Accepted, 3rd May, 1890
PROVISIONAL SPECIFICATION.
Improvements in Steam Boilers.
I DANIEL THOMAS LAWSON, of Wellsville, Columbiana County, Ohio, United
States of America, Merchant do hereby declare the nature of this invention to be as
follows:-
My invention comprehends certain improvements upon the steam boiler, for which
I obtained previous Letters Patent dated April 28th 1880, No. 1749. In the
specification of that Patent I describe and claim a process of preventing steam boiler
explosions by retarding or prolonging the flow of steam from the water space to the
steam space by means of a diaphragm or partition having a valved opening of less
size than the outlet from the stean space, whereby the sudden conversion of water
into steam (due to the abstraction of steam from the steam space) is prevented, and
its concussive effect upon the boiler is avoided.
In accordance with my theory as expressed in said specification, it has been
demonstrated that steam boiler explosions are mainly due to a sudden reduction of
steam pressure, and the immediate conversion of hot water into steam with explosive
energy which, having no relief, bursts the boiler. The causes which produce this
sudden reduction of steam pressure upon the water are, first, the sudden opening of
the throttle valve and rush of steam into the cylinder, being instantly followed by the
closure of the steam port, as in starting the engine; secondly, the injection of cold
water into the steam space in starting the feed pumps which causes an instantaneous
condensation of steam, this being liable to occur when the inlet end of the feed water
pipe terminates too high in the boiler, or when the feed pipe is uncovered by the
lowering of the water in the boiler by the careening of the boiler on shipboard. It
will thus appear that a risk of explosion is always involved when steam is allowed to
escape from the boiler, and its escape suddenly arrested, or the pressure upon the
heated water in the boiler is suddenly reduced without adequate vent to carry off the
concussive strain produced by the bursting of the heretofore quiescent hot water into
steam.
As
In the specification before referred to, I employed a slide valve attached to a stem
and extending through the shell of the boiler, which valve could be adjusted at will
over the opening in the diaphragm separating the steam from the water space.
the adjustment of the size of this opening to the escape of steam required nice judg-
ment on the part of the engineer, only the most expert engineers could make available
the full advantages of my invention, while the other class of unskilled engineers are
the very ones who need it most.
My present invention is intended to render the boiler automatic in its action in
accordance with my theory, so that all may profit by its advantages without the
exercise of judgment, and whereby also the firing surface of the boiler is rendered
free from incrustation, and is self cleaning to a certain extent.
The horizontal diaphragm runs lengthwise of the boiler and separates the water
space from the steam space as before. The boiler may be of any desired size or shape,
and may be provided with return flues or fire tubes. In the diaphragm are formed
several openings, and over each of these openings is arranged a check valve opening
upwardly and held down by a weight or spring. The aggregate size of these openings
s considerably less than the size of the steam outlet from the steam space, so that
steam will pass from the lower space to the upper space somewhat slower than it will
escape from the upper space through the steam outlet, so that no matter how impulsive
or intermittent he escape of steam from the steam space may be, the passage of the
team from the lower space to the upper-space is more or less constant or prolonged
hrough a greater space of time, thus avoiding a sudden removal of pressure from the

page_text: water, and the resultant concussive strain. These automatic valves open whenever the
steam pressure is reduced by discharge from the upper space, and they serve another
very important function, which I will now proceed to explain.
I have found in the operation of my boiler that all the sedimentary matters which
produce scale or incrustation, are thrown up on the diaphragm, and if they can be
held there and eliminated before they are allowed to wash back into the water
compartiment by overflow of the diaphragm, which may under certain conditions
occur, and cause them to settle upon the bottom plates and Aues where they may be
burned into adherence to the iron, my boiler can be made self cleaning and free from
scale. Ordinarily, when the boiler is in action, the sedimentary matters when first
eliminated do not adhere to the boiler, but when the boiler is at rest they settle down
upon the fire surface of the boiler, and when the boiler is fired up they become
burned into an adhering incrustation which in a short time seriously interferos with
the steaming capacity of the boiler, involving a great waste of fuel as well as injury
to the iron.
With my diaphragm these sedimentary matters pass to the upper side of the
diaphragm when the boiler is in action and are there retained by the automatic check
valves on a surface out of contact with the fire where they cannot become incrusted
but may be blown off in the form of a slush or semi-fluid mass. To facilitate this
action the diaphragm is formed with trough like grooves on its opposite sides, and at
the lower ends of these troughs there are blow-off pipes by which the troughs may
be cleaned of their load of impurities. By this means the firing surface of the boiler,
as well as flues, is always kept clean and free from incrustation and capable of a
maximum steaming effect.
In connection with the valved openings in the diaphragm, I may use a number of
small holes of about a quarter of an inch in diameter which act in conjunction with
the valved openings, but which always remain open and effect the liberation of
perfectly dry steam. These openings should, however, he computed in with the valve
openings in determining the aggregate area of the openings in the diaphragm,
which should always be kept considerably below the area of the discharge openings
from the steam space.
D: 59-1 of L. 1930
COMPLETE SPECIFICATION.
Improvements in Steam Boilers.
I DANIEL THOMAS LAWSON, of Wellsville, Columbiana County, Ohio, United
States of America, Merchant 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 :—
My invention comprehends certain improvements upon the steam boiler, for which
I obtained previous Letters Patent dated April 28th 188, No. 1749. In the
specification of that Patent I describe and claim a process of preventing steam boiler
explosions by retarding or prolonging the flow of steam from the water space to the
steam space by means of a diaphragm or partition having a valved opening of less
size than the outlet from the steam space, whereby the sudden conversion of water
into steam (due to the abstraction of steam from the steam space) is prevented, and its
concussive effect upon the boiler is avoided.
In accordance with my theory as expressed in said specification, it has been demon-
strated that steam boiler explosions are mainly due to a sudden reduction of steam
pressure, and the immediate conversion of hot water into steam with explosive energy
which, having no relief, bursts the boiler. The causes which produce this sudden
reduction of steam pressure upon the water are, first, the sudden opening of the
throttle valve and rush of steam into the cylinder, being instantly followed by the

page_text: It
closure of the steam port, as in starting the engine; secondly, the injection of cold
water into the steam space in starting the feed pumps which causos an instantaneous
condensation of steam, this being liable to occur when the inlet end of the feed water
pipe terminates too high in the boiler, or when the feed pipe is uncovered by the
lowering of the water in the boiler by the careening of the boiler on ship board.
will thus appear that a risk of explosion is always involved when steam is allowed to
escape from the boiler, and its escape suddenly arrested, or the pressure upon the
heated water in the boiler is suddenly reduced without adequate vent to carry off
the concussive strain produced by the bursting of the heretofore quiescent hot water
into steam.
As
In the specification before referred to, I employed a slide valve attachod to a stem
and extending through the shell of the boiler, which valve could be adjusted at will
over the opening in the diaphragin separating the steam from the water space.
the adjustment of the size of this opening to the escape of steam required nice
judgment on the part of the engineer, only the most expert engineers could make
available the full advantages of my invention, while the other class of unskilled
engineers are the very ones who need it most.
My present invention is intended to render the boiler automatic in its action in
accordance with my theory, so that all may profit by its advantages without the
exercise of judgment, and whereby also the firing surface of the boiler is rendered
free from incrustation, and is self cleaning to a certain extent.
Reference is to be had to the accompanying drawing forming part of this
specification wheroin
Figure is a side elevation of the boiler, with a portion of the shell and also a
portion of the diaphragm broken away to show the internal construction.
Figure 2 is a transverse section of the boiler.
The same letters of reference serve for like parts in both the figures.
A is the shell of the boiler. B is the horizontal diaphragm running lengthwise of
the boiler and separating the water space from the steam space C. The boiler may
be of any desired size or shape, and may be provided with return flues or fire tubes.
In the diaphragm B are formed several openings a and over each of these openings
is arranged a check valve opening upwardly and held down by a weight or spring.
The aggregate size of these openings is considerably less than the size of the steam
outlet o from the steam space, so that steam will pass from the lower space C to the
upper space C somewhat slower than it will escape from the upper space through the
steam outlet, so that no matter how impulsive or intermittent the escape of steam
from the steam space may be, the passage of the steam from the lower space C to the
upper space is more or less constant or prolonged through a greater space of time,
thus avoiding a sudden removal of pressure from the water, and the resultant con-
cussive strain. These automatic valves open whenever the steam pressure is reduced
by discharge from the upper space C, and they serve another very important function,
which will now proceed to explain.
I have found in the operation of my boiler that all the sedimentary matters which
produce scale or incrustation, are thrown up on the diaphragm, and if they can be
held there and eliminated before they are allowed to wash back into the water com-
artment by overflow of the diaphragm, which may under certain conditions occur,
nd cause them to settle upon the bottom plates and flues where they may be burned
nto adherence to the iron, my boiler can be made self cleaning and free from scale.
Ordinarily, when the boiler is in action, the sedimentary matters when first eliminated
to not adhere to the boiler, but when the boiler is at rest they settle down upon the
ire surface of the boiler, and when the boiler is fired up they become burned into an
dhering incrustation which in a short time seriously interferes with the steaming
apacity of the boiler, involving a great waste of fuel as well as injury to the
on.
With my diaphragm these sedimentary matters pass to the upper side of the
iaphragm when the boiler is in action and are there retained by the automatic check
alves on a surface out of contact with the fire where they cannot become incrusted

page_text: To facilitate this
but may be blown off in the form of a slush or semi-fluid mass.
action the diaphragm is formed with trough like grooves e e on its opposite sides, and
at the lower ends of these troughs there are blow-off pipes ff by which the troughs
may be cleaned of their load of impurities. By this means the firing surface of the
boiler, as well as flues, is always kept clean and free from incrustation and capable of
a maximum steaming effect.
In connection with the valved openings in the diaphragm, I may use a number of
small holes of about a quarter of an inch in diameter which act in conjunction with
the valved openings, but which always remain open and effect the liberation of per-
fectly dry steam. These openings should, however, be computed in with the valve
openings in determining the aggregate area of the openings in the diaphragm, which
should always be kept considerably below the area of the discharge openings from the
steam space.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is ;
1. The steam boiler having its steam space separated from the water space by a
horizontal diaphragm provided with openings in the same and combined with
upwardly-opening check valves arranged above the diaphragm substantially as and
for the purpose described.
2. The combination, with a steam boiler, of a horizontal diaphragm separating the
steam space from the water space and provided with upwardly-opening check valves
and gathering troughs for sediment and blow-out pipes extending through the boiler
from the level of the troughs, substantially as and for the purpose described.
Dated this dist day of March 1890.
Dated us IS LINY OT BRATCH
D. I. LAWR
By A. M. & Wm. Clark,
58, Chancery Lane, London, l'atent Agents.