IMPROVEMENTS IN STEAM BOILERS
Year: 1873

page_text: LETTERS PATENT to John Griffith, of the City and State of New
York, United States of America, now of No. 8, Southampton
Buildings, London, Engineer, for the Invention of "IMPROVEMENTS
IN STEAM BOILERS."
Sealed the 8th August 1873, and dated the 21st June 1873.
COMPLETE SPECIFICATION filed by the said John Griffith at the Office
of the Commissioners of Patents, with his Petition and Declaration,
on the 21st June 1873, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GRIFFITH, of the City and State of New York, United States of.
America, now of No. 8, Southampton Buildings, London, Engineer,
send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
STEAM BOILERS," and have petitioned Her Majesty to grant unto me, my
executors, administrators, and assigns, Her Royal Letters Patent for the
'

page_text: Inventor thereof.
NOW KNOW YE, that I, the said John Griffith, 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, reference being had to the accompanying Drawings forming
a part of this Specification:-
My said Invention relates to that class of boilers which have tubes
wherein the water is heated, and separate chambers or spaces in which
the steam generated from the water in the said tubes is collected.
The peculiar features of my improved boiler are as follows:-It is
constructed with heating tubes, water chambers, and passages, so
arranged that there is a continuous circulation of the water through
them during the working of the boiler. The ends of the aforesaid
tubes are connected with each other by heads of peculiar construction
and arrangement. These heads also form the means whereby the said
tubes, when arranged in the manner herein-after described, communicate
through straight vertical passages with the water chambers above them.
Above the said water chambers I place steam chambers, each of which
has a separate connection with the said water chambers. The latter
are provided with blow-off cocks or valves for ejecting the scum or
other foul substances. I connect the lower row of heating tubes with
a transverse tube which has a blow-off cock or valve at one end, and
I provide the vertical passages or circulation tubes at the rear of the
boiler with valves or cocks for closing the said vertical passages, and
reversing the circulation of the water in the boiler when the said
blow-off valve is onened.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a front elevation of my improved boiler; Figure 2 is a
longitudinal section on the line a, x, Figure 1; Figure 3 is a rear
elevation of the said boiler.
Figures 4 and 5 shew an improved form of bricks used in constructing
the aforesaid deflectors.
Similar letters indicate the same parts throughout the Drawings.
A is the furnace or fire-place which may be constructed in any
suitable and convenient manner; a, a, are the aforesaid heating tubes
which are preferably arranged with the inclination shown in Figure 2;
b, b, are the heads which connect the front and rear ends of these tubes
with each other, and which form vertical and horizontal circulating
passages. The vertical passages at the front of the boiler communicate
by pipes c with the water chambers or drums d.
In Figure 3 it will be seen that the tubes a are not connected
centrally with the heads b, but that each tube is inserted into the
head nearer to one side than the other side of the same. The object
of this arrangement is the leaving of sufficient space in the heads at
the sides of the tubes to make the vertical passages through the heads
quite straight or direct through the entire series. And by the formation
of these straight passages in the heads at the front of the boiler I obtain
a perfectly straight or direct communication between the said tubes and
the water chambers, and there will be no impediment to the free cir-
culation of the water throughout the boiler.
It will be seen by referring to the last-mentioned Figure of the
Drawing that the tubes a are not placed in vertical rows, so that the
tubes of each row are over the spaces of the row next below it. This
arrangement of the tubes a is obviously the best for obtaining the
greatest effect of the heat upon the water in the said tubes, but it
necessitates the peculiar contrivance above described for obtaining
straight or vertical passages. The horizontal passages through the
leads permit a perfectly free transverse circulation of the water,
so that if there is a more rapid evaporation at one part of the boiler
than at the other parts the water will flow towards that part.
It will be seen from the foregoing description that in this improved
boiler the water will circulate longitudinally through the tubes a, water

page_text: chambers d, and vertical pipes c, c¹, and that it will also circulate
horizontally and transversely through the heads to or from any of the
said tubes a. The heads are secured together by bolts b¹, b², passed
horizontally and vertically through them.
Another very important feature of my Invention is the making of
the front vertical passages or up-take tubes c larger than the bore
of the tubes a, so that the water may rise freely through the said
passages to the water chambers d wherein the steam is disengaged
from the water, and from which it rises into the steam chambers e.
Furthermore I consider it of great importance that the vertical
passages cat the front of the boiler, and whereby the water ascends,
should be more numerous than the passages c¹ at the back through
which the water descends, that is to say, I prefer to provide at the
front end of each water chamber two vertical passages, and at the
rear end one vertical passage. This relative proportion of the front
and rear passages is necessary because of the quantity of water
evaporated after its ascension into the water chambers d. The steam
chambers e are placed transversely over the water chambers d, as
shown in Figure 1; each of the said steam chambers has a separate
communication with the opposite ends of the water chambers d by the
flanged pieces f which rest upon and are secured to the saddles g
on the said water chambers, and whose upper flanges receive and
support the steam chambers. Each of the steam chambers e is pro-
vided with a branch piece / fitted with a safety valve i. These
branch pieces are connected by a pipe j, in the centre of which I
place the stop valve k, whereby I take the steam from the boiler.
By having this valve arranged midway between the two steam
chambers, I prevent the escape of water with the steam, as any
water passing through the pipe j in one direction would be driven
back by the pressure of steam in the opposite direction. The water
chambers d are supported upon girders whose ends rest on the pillars
or columns m. The entire upper structure of the boiler is thus
supported quite independently of the tubes a and their connections,
and the expansion and contraction of any part will not affect the
other parts of the boiler. The water chambers d are provided at the
rear end with man-holes fitted with covers, as shown at n.
At the front of the boiler the vertical passages through the heads b
are connected, as above specified, by the curved pipes or pieces o with

page_text: the water chambers d. I prefer to have two of these connections for
each water chamber. At the rear or back of the boiler the water
chambers & have branch pieces o flanged at p to connect with vertical
pipes c', which conduct the water down from the water chambers d
to the tubes a. By referring to Figure 3 it will be seen that these
down-take pipes c¹ are arranged outside of the boiler and away from
the heat, so that they are always cool in comparison with the other
parts of the boiler, and the water will therefore naturally descend
through them when the boiler is working. And although the position
and direction of these down-take pipes need not be strictly in accordance
with the Drawing, yet they must alway be so arranged as to be cooler
than the up-take pipes. It will also be seen that the pipes c¹ arc shewn
connected with the bottom of the water chambers and with the lower
row of tubes, and this arrangement gives the best result. The lower
end of each pipe c¹ is provided with a valve 13 the said valves are
all connected with a rod 71, or are provided with other suitable means
whereby they are conveniently opened and closed. When these valves
are open the water circulates through the tubes a and water chambers d
in the direction of the arrows 1, and during this circulation the
evaporation will be very rapid, but when these valves are closed the
circulation is arrested and the evaporation greatly diminished. I
connect the lower row of the tubes a with the cross pipe s, which
has at one end a blow-off valve or cock s¹. And as herein-before
stated when the valves are closed and the said blow-off cock s¹ is
opened, the circulation of the water is reversed, and the water in the
boiler will rush down the tubes a to the pipe s, and will carry with it
any scale or dirt which may have accumulated in the said tubes or
other parts of the boiler. The cross pipe s has opposite each of the
tubes a to which it is connected a covered hand hole at 8. There
are also hand holes on the front heads of the said tubes, and the other
tubes a are also provided at both ends with similar hand holes, which
when their covers are removed permit the said tubes to be examined.
The blow-off cocks whereby the water chambers are cleansed may
be arranged as shown, or I may have a cross pipe connected with all
of the said water chambers, and provided with a blow-off cock or valve
at one end.
In Figure 2 I have shown deflectors or shields u, u¹, u², formed of
fire-bricks. v is a cavity made in the brickwork below the tubes to

page_text: permit the heat to pass down and up freely between the said deflectors.
The form of the bricks of which the latter are constructed is clearly
shown in Figures 4 and 5. The bricks w are formed to fit closely
to the said tubes and to make them perfectly tight around the same;
fire-clay or other refractory material may be applied to them; the said
bricks are also recessed at the edges and fitted together as shown in
Figure 5.
In the accompanying Drawing I have shown a convenient form and
arrangement of the parts of my improved boiler, but I do not limit
myself to such form and arrangement as the same may be varied in
many respects without departing from the principle of my Invention.
For example, instead of arranging a number of water chambers longi-
tudinally over the heating tubes, I may place one or a number of such
water chambers transversely over the said tubes. The up-take water
tubes or passages would in this arrangement be nearly the same as
shewn, but the down-take tubes would be inclined towards the rear
end of the said heating tubes, and curved or bent to the proper shape
to connect with the rear heads or ends of the said tubes. Moreover
instead of having cylindrical steam chambers placed above the water
chambers, as shewn, I may construct the water chambers with steam
domes, or in cases where it is desired to use cylindrical steam chambers;
but where they cannot be arranged as shewn, they may be placed in
any position or part of the building most convenient for the purpose,
and made to communicate with the water chambers by suitable pipes
and connections.
Other modifications of the arrangements of the parts of my improved
boiler may also be adopted to suit any peculiar circumstances so long
as such modifications do not affect the principle of its construction, that
is to say, the arrangement and connection of the parts for maintaining
a continuous circulation of the water during the working of the boiler.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,—
First. A steam generator or boiler constructed with heating tubes,
a water chamber, or number of such chambers, and ascending and
descending passages so arranged and connected that a circulation of
the water longitudinally through the boiler is maintained during the
working of the same.

page_text: Second. A steam boiler or generator constructed with heating tubes,
water chambers, and passages, wherein a longitudinal circulation of the
water is maintained, as aforesaid, and which has the said heating tubes
so connected as to permit a free horizontal or transverse circulation of
the water in them for the purposes specified.
Third. A steam boiler or generator constructed with heating tubes,
water chambers, and steam chambers combined, and connected with
each other as herein set forth and for the purposes specified.
Fourth. Constructing and fitting together the heads at the ends of
the said heating tubes in such manner that when the tubes are arranged
as shown in the Drawing the vertical passages through the said tubes
will be straight or direct and larger than the bore of the said tubes, as
herein set forth and for the purpose specified.
Fifth. The cocks or valves in the back or descending circulation
pipes, and the cross pipe with the blow-off cock or valve at the end
of the said pipe, arranged in combination with the heating tubes, as
herein set forth and for the purpose specified.
Sixth. Constructing the heat deflectors or shields of bricks formed,
as shewn in Figures 4 and 5, and fitted between the heating tubes, as
hercin set forth.
In witness whereof, I, the said John Griffith, have hereunto set my
hand and seal, this Twelfth day of June, in the year of our Lord
One thousand eight hundred and seventy-three.