PROVIDIUNAL Improvements in Steam Generators.
Year: 1893

page_text: Date of A plication, 16.h Set., 1893
Complete Specification Left, 10th Apr., 1894 -Accepted, 19th May,
1894
PROVIDIUNAL
Improvements in Steam Generators.
I, JOHN WHITE DAVIS, of Battlefield, Wash Common, Newbury, in the County
of Berks, Boiler-maker, do hereby declare the nature of this invention to be as
follows:-
This invention relates to Improvements in Steam Generators intended more
particularly for marine purposes, and the object of the invention is to obtain a
generator which will afford free access to the tubes and other parts for cleaning
and repairs, which will bear a heavy pressure with little or no risk of injury to the
tubes and which will rapidly produce a large volume of steam with a minimum
consumption of fuel.
In carrying my invention into effect, I construct the generator with two longi-
tudinal lower water chambers hereinafter referred to as the "lower chambers,"
preferably of circular form, extending from end to end thereof, one located on each
side of the furnace and with an upper longitudinal water and steam chamber
hereinafter referred to as "the upper chamber" also preferably of circular form,
arranged centrally with regard to the lower chambers and some distance above
them so that the three chambers are arranged approximately in the form of a
triangle.
Instead of two lower chambers there may be three chambers arranged longi-
tudinally and equidistant with two furnaces one in each space between the lower
chambers and in this case there will be two upper longitudinal chambers arranged
equidistant from each other and centrally between and at some distance above two
of the lower chambers, thus forming approximately two triangles, the centre lower
water chamber being common to both triangles.
The feed water is supplied to the upper chamber and this chamber is connected
longitudinally to both the lower chambers by inclined water tubes for the entire
length of the generator, these tubes form the sides of the triangle and the tubes
constituting each side are arranged approximately parallel to each other, the
several chambers being slightly flattened to receive the ends of water tubes whilst
a semi-circular baffle plate is arranged within the upper chamber over the apertures
of the inclined tubes to control or regulate the circulation of water issuing from the
tubes and prevent priming. The tubes are fixed in the various chambers either by
screwing or expanding with an ordinary expander.
I connect the upper and lower chambers at both ends by means of water spaces,
and, longitudinally of my generator in the space above the furnace between the
sides of the triangle, I place a number of approximately horizontal but slightly
inclined water tubes connecting the two end water spaces together, thus enabling a
most rapid and complete circulation of the water to take place, these tubes are
secured to the tube plates either by screwing or expanding.
I form each of the end water spaces by means of two plates, one plate I term the
"tube plate" and the other the "end plate." To the tube plates are connected the
upper and lower chambers and also the horizontal inclined tubes and I dish these
plates out to a certain extent to partially form the water space, I also flange them
back all round the outside and thus form a flat surface of sufficient width to form a
joint, and, to this flat surface, I bolt my end plates, these end plates 1 dish in a
similar manner but in an opposite direction to the tube plates and thus form an
ample water space at both ends; this dishing also strengthens the end plates them-
selves and enables thin plates to be used, those parts of the cud plates which cover
over the openings of the upper and lower chambers I strengthen by dishing out

page_text: into a semi-spherical shape and I connect the two end plates together by means of
longitudinal stays passing right through the upper and lower chambers, such stays
being provided with shoulders or nuts at each end for the end plates to butt against
and nuts outside to hold the plates against internal pressure; I also strengthen
those parts of the end and tube plates which come between the sides of the triangle
by means of stays fixed into the tube plate, either by screwing in and rivetting over
or by screwing in and nutting, which stays are fitted with nuts or shoulders for the
end plates to butt against and nuts outside in a similar manner to the longitudinal
stays which pass through the chambers.
The furnace or furnaces which lie between the lower water chambers may extend,
if required, the whole length of the generator, or, in case of long boilers the
generator may be fired from both ends. I enclose the generator in a suitable casing
and place the funnel on the top either in the centre or at either end the flame and
hot products of combustion passing up among the horizontal tubes and out through
the spaces between the tubes forming the sides of the triangle.
I sometimes introduce baffle plates so that the hot gases after passing among the
horizontal tubes may be effectually distributed among the inclined tubes before
leaving by the funnel.
By the construction hereinbefore described, I am enabled readily to obtain access
to the interior of the generator for the purpose of repairs cleaning or otherwise, as,
by slackening or taking off the nuts of the bolts and stays, I am enabled to take off
either end plate, and, moreover, by reason of the end water spaces, I dispense
entirely with brick ends to the boiler thus obtaining a much cooler stokehole than
heretofore, and furthermore, by reason of the peculiar configuration of the end
plates, I am enabled to use comparatively thin plates with very little staying even
when using a very high pressure and thus the weight of the generator will be
considerably beneath the weight of an ordinary marine boiler.
Dated this 16th day of September 1893.
VAUGHAN & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I, JOHN WHITE DAVIS, of Battlefield, Wash Common, Newbury, in the
County of Berks, Boiler-maker, 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 Improvements in Steam Generators intended more
particularly for marine purposes, and the object of the invention is to obtain a
generator which will afford free access to the tubes and other parts for cleaning
and repairs, which will bear a heavy pressure with little or no risk of injury to the
tubes and which will rapidly produce a large volume of steam with a minimum
consumption of fuel.
In carrying my invention into effect, I construct the generator with two
longitudinal lower water chambers bereinafter referred to as "the lower chambers'
preferably of circular form, extending from end to end thereof, one located on each
side of the furnace and with an upper longitudinal water and steam chamber herein-
after referred to as "the upper chamber also preferably of circular form, arranged
centrally with regard to the lower chambers and some distance above them so that
the three chambers are arranged approximately in the form of a triangle.
The feed water is supplied to the upper chamber and this chamber is connected
longitudinally to both the lower chambers by inclined water tubes for nearly the
entire length of the generator and these tubes, which are reduced at each end, form
the sides of the triangle and the tubes constituting each side are arranged

page_text: approximately parallel to each other, the several chambers if desired being slightly
flattened to receive the ends of water tubes, whilst a semi-circular baffle plate is
arranged within the upper chamber over the apertures of the inclined tubes to
control or regulate the circulation of water issuing from the tubes and prevent
priming. The tubes are fixed in the various chambers either by screwing or
expanding with an ordinary expander.
I connect the upper and lower chambers at both ends by means of water spaces,
and, longitudinally of my generator in the space above the furnace between the
sides of the triangle, I place a number of approximately horizontal but slightly
inclined water tubes connecting the two end water spaces together, thus enabling
a most rapid and complete circulation of the water to take place, these tubes are
secured to the tube plates either by screwing or expanding.
I form each of the end water spaces by means of two plates, one plate I term
the "tube plate" and the other the "end plate." To the tube plates are connected
the upper and lower chambers and also the horizontal inclined tubes and I dish
these plates out to a certain extent to partially form the water space, I also flange
them back all round the outside and thus form a flat surface of sufficient width to
form a joint and to this flat surface I bolt my end plates, these end plates I dish in
a similar manner but in an opposite direction to the tube plates and thus form an
ample water space at both ends; this dishing also strengthens the end plates them-
selves and enables thin plates to be used, those parts of the end plates which cover
over the openings of the upper and lower chambers I strengthen by dishing out
into a semi-spherical shape and I connect the two end plates together by means
of longitudinal stays passing right through the upper and lower chambers such
stays being provided with shoulders or nuts at each end for the end plates to butt
against and nuts outside to hold the plates against internal pressure, I also strengthen.
those parts of the end and tube plates which come between the sides of the triangle
by means of stays fixed into the tube plate either by screwing in and rivetting over
or by screwing in and nutting, and which stays are fitted with nuts or shoulders
for the end plates to butt against and nuts outside in a similar manner to the
longitudinal stays which pass through the chambers.
The furnace or furnaces, which lie between the lower water chambers, may extend,
if required, the whole length of the generator, or, in case of long boilers, the
generator may be fired from both ends. I enclose the generator in a suitable
casing and place the funnel on the top either in the centre or at either end, the
flame and hot products of combustion passing up among the horizontal tubes and
out through the spaces between the tubes forming the sides of the triangle.
I sometimes introduce baffle plates so that the hot gases after passing among
the horizontal tubes may be effectually distributed among the inclined tubes before
leaving by the funnel.
And, in order that the said invention may be more clearly understood and readily
carried into effect, I will proceed, aided by the accompanying drawings, more fully
to describe the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1. is a side elevation of a steam generator constructed according to the
present invention.
Figure 2. is an end elevation thereof partly in section.
Figure 3. is a vertical longitudinal section taken on the line 1-1. of Figure 2.
Figure 4. is a similar view to Figure 3. but representing a slight modification.
Figure 5. is a similar view to Figure 2. but representing a more powerful form
of generator.
In the several figures like parts are indicated by similar letters of reference.
Referring to Figures 1. to 3., a. a. represent the two longitudinal lower water
chambers and these chambers are preferably circular in section or approximately
so, and extend from end to end of the generator, one of the chambers being located
upon each side of the furnace d.

page_text: The generator is also provided with an upper longitudinal water and steam
chamber b. also preferably of circular form and arranged centrally with regard to
the lower chambers a., and some distance above them so that the three
chambers a. a. and b. are arranged approximately in the form of a triangle.
The feed water is supplied to the upper chamber b. by means of a feed pipe
and this upper chamber . is connected longitudinally with both the lower
chambers a. by inclined water tubes c. for the entire or nearly the entire length of
the generator; these tubes c. form the sides of the triangle hereinbefore referred
to and the tubes constituting each group or side are arranged approximately
parallel to each other, the several chambers a. b. being slightly flattened to receive
the ends of the water tubes c. which are fixed therein either by screwing or
expanding by the aid of an ordinary expander.
Some of the tubes c. at the bridge end of the furnace may as indicated in the
drawings be curved or bent in a horizontal direction and caused to enter the
adjacent water space a* hereinafter more fully referred to and the object of this
arrangement is to promote the circulation of the water and to facilitate the cleansing
of the exterior of the inclined water tubes.
Semi-circular baffle plates supported by brackets from the walls of the
chamber are arranged within the upper chamber over the ends of the inclined
tubes e. so as to control or regulate the circulation of water issuing from the tubes c.
and to prevent priming.
The upper and lower chambers a. are connected at both ends by means of
water spaces a
*and longitudinally of the generator in the space above the furnace
between the sides of the triangle are placed a number of approximately horizontal
but inclined water tubes e. which connect the two end water spaces a* thus enabling
a most rapid and complete circulation of the water to take place; whilst these
tubes are secured to their tube plates. by screwing or expanding.
Each of the end water spaces a" is formed by means of two plates f. g., the
one of these plates I term the "tube plate," and the other g. the end plate."
To the tube plates f. are connected the upper and lower chambers b. a. and also
the horizontal inclined tubes e. as herein before described and the tube plates are
dished or bent at f' to some extent to partially form the water spaces a* and they
are provided with flanges of sufficient width to form a joint and to these
flanges are bolted the end plates g.
The end plates g. are dished at g' in a similar manner to that hereinbefore
described with respect to the tube plates f. but in an opposite direction, thus
forming an ample water space a* at both ends of the generator, whilst the end
plates g. are provided with Hanges similar to the flanges 2 of the tube plates f.,
the two flanges being firmly bolted together.
The dishing of the end plates g. in addition to partially forming the water
space a also assists to strengthen the end plates g. thus enabling comparatively
thin plates to be used.
Those parts of the end plates g. which are opposite or cover over the openings
of the upper and lower chambers b. a. are further strengthened by dishing out
at into a semi-spherical shape and the end plates g. are connected together by
means of longitudinal stays passing through the dished parts g³ and through the
upper and lower chambers b. a. and these stays 7' are at each end provided with
shoulders go for the dishings g3 of the plates g. to butt against and with nuts g
screwing upon the extreme ends of the stays 9 this arrangement of parts having
for its object to strengthen the plates g. against internal pressure.
Those parts of the end plates g. and tube plates which come between the
sides of the triangle are also strengthened by means of short stays h. fixed into
the tube plates. by screwing in and rivetting over, or, they might be otherwise
fixed, and which are secured to the end plates g. by means of shoulders h
provided for the end plates g. to butt against and with nuts h upon their extreme
ends to hold the plates g. up to the shoulders h in a similar manner to that
adopted with respect to the longer stays g' hereinbefore referred to.

page_text: The furnace or furnaces d. which lie between the lower water chambers a. may
extend if required the whole length of the generator or in the case of long boilers.
or generators the furnace may be fired from both erds.
The generator is enclosed at the sides by means of plates i. constituting a casing
or a separate casing covering the entire device might be employed, and the
funnel j. is placed at the top of the generator and at one end thereof and descends.
in the form of a saddle which may embrace the upper chamber b. from end to
end and below such chamber the saddle j¹ connects with the combustion chamber,.
the flame and bot products of combustion passing up amongst the horizontal
tubes e. and out through the spaces between the tubes e. forming the sides of the
triangle.
Baffle plates are sometimes introduced into the combustion chamber so that the
hot gases after passing amongst the horizontal tubes e. may be effectually
distributed among the inclined tubes c. before passing away to the funnel j., but
such plates are not shown in the accompanying drawings as the arrangement thereof
will be readily understood by a competent mechanic.
In the example given at Figure 4., is shown a slight modification in the method
of forming the water spaces a*.
In this case, in lieu of dishing both the tube plate f. and end plate g, at gl
as previously described with respect to Figures 1., 2., and 3., only the tube plate f..
is so dished the end plate y. being formed with a general flat surface bolted to the
flange of the tube plate f., the dishings y³ however remaining the same as in
the previous figures.
In the example given at Figure 5., the system hereinbefore described is some-
what extended so as to give a more powerful generator.
In this case, instead of two lower chambers a., three of such chambers are
arranged longitudinally and equi-distant from each other, whilst two furnaces d.
are disposed one in each space between the lower chambers a. whilst two upper
chambers b. are provided arranged centrally between and some distance above two
of the lower chambers a., thus forming approximately two triangles the centre
water chamber a. being common to both triangles.
In this example, the saddles are connected by flues with the chimney j. in
order to carry off the products of combustion from both furnaces d.
By the construction of generator hereinbefore described, I am enabled readily
to obtain access to the interior of the generator for the purpose of repairs,
cleaning or otherwise, as by slackening back or taking off the uuts gh² of the
stays and h. I am enabled to loosen or take off either end plate g. like a
cylinder cover and moreover by reason of the end water spaces a* I am enabled
to dispense entirely with brick ends to the generator, thus making a much cooler
stoke-hole than heretofore, and furthermore by reason of the peculiar configuration
of the end plates g. I am enabled to use comparatively thin plates with very little
independent staying, even when using very high pressure, and thus the weight of
the generator will be considerably less than that of an ordinary marine boiler.
Furthermore the area of the heating surface is very great and practically no
part of the generator escapes the heat of the furnace and products of combustion
whilst at the same time the circulation of the water is very rapid.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. In a steam generator, the combination of a furnace, a lower water chamber,
located upon each side of such furnace and extending the entire length of the
generator or nearly so, a corresponding upper water and steam chamber located
above the furnace and centrally of the lower chambers, a number of vertical
inclined water tubes connecting the lower chambers with the upper chamber,
water chambers forming end walls to the generator and communicating with the
upper and lower chambers and a number of longitudinal inclined water tubes

page_text: connecting the end water chambers, substantially as herein shown and described and
for the purpose stated.
2. In a steam generator of the character referred to in Claim 1., forming the
end water chambers by means of dished tube plates and end plates, substantially
as herein shown and described and for the purpose stated.
3. In a steam generator of the character referred to in the preceding claims,
forming the end plates with a dishing of semi-spherical form located opposite the
ends of the upper and lower chambers, substantially as herein shown and
described and for the purpose stated.
4. In a steam generator of the character referred to in Claim 1., forming the
end water chambers by means of dished tube plates and end plates the latter
being removeably bolted to the former, substantially as herein shown and described
and for the purpose stated.
Dated this 9th day of April 1894.
VAUGHAN & SON,
Agents for the Applicant.