Year: 1897

page_text: I, LEONARD JENNETT TODD, of 25, Brooke Road, Stoke Newington, in the County
of Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:
-
This invention relates to that class of steam boilers in which there is a firebox
in the lower part, from the roof of which fire tubes are carried upwards to a smoke-
box, which may be either wet or dry, at the top of the boiler.
The fire tubes are arranged in the furnace roof in an annular manner, so as to
leave a large space in the center of the boiler free from tubes. Then, in the water
space of the boiler, a little distance above the top of the furnace I place a circu-
lating plate, pierced with holes for the tubes to pass through, and which turns
upwards with a large opening into the central space which is free from tubes.
And when a dry smokebox is used, I place a deflector in the upper part of the open
central water space.
If the boiler is of large size, more than one water space may be formed amongst
the tubes, instead of the single central space before described, and the circulating
plate will then be formed with an additional upward discharge hole, for the
additional free water space; and each space will then have its own deflector, if such
is required.
The circulating plate may either be flat, or may be coned upwards from the cir-
cumference to the central or other discharge hole; and if desired, may be made to
partly surround the sides of the furnace, in addition to covering the top of the
same.
With a boiler constructed in this manner, a circulation of water, directly over
the roof of the furnace crown towards the central or other open space, commences
whenever the fire is lighted. And as the heat increases the circulation becomes more
rapid, until with a hot fire, a violent stream of water washes over the furnace top,
and pours up the central or other space, until when meeting with its deflector, it is
thereby compelled to spread laterally amongst and throughout the tubes. So that
the lower part of the tubes are thus first washed transversely with a rapid current
advancing towards the central or other open space, and are then again washed
transversely by the same current returning from the central or other open space
towards the outer part of the boiler.
Dated this 5th day of May 1897

page_text: I, LEONARD JENNETT TODD, of 25, Brooke Road; Stoke Newington, in the County
of Middlesex, 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 relates to that class of steam boilers in which there is a firebox
in the lower part, from which fire tubes are carried upwards to a smokebox, which
may be either wet or dry, at the top of the boiler.
According to one type of my invention, the fire tubes are arranged in the
furnace roof in an annular manner, so as to leave a large space in the center of the
boiler free from tubes. Then, in the water space of the boiler, a little distance
above the top of the furnace I place a circulating plate, pierced with holes for the
tubes to pass through, and which turns upwards with a large opening into the
central space which is free from tubes. And when a dry smokebox is used, I place
a deflector in the upper part of the open central water space, when it is desired to
spread the rising current of water laterally amongst the tubes.
If the boiler is of large size, more than one water space may be formed amongst
the tubes, instead of the single central space before described, and the circulating
plate will then be formed with an additional upward discharge hole, for each
additional free water space; and each water space will then have its own deflector,
if such is desired.
The circulating plate may either be flat, or may be coned upwards from the
circumference to the central or other discharge hole; and if desired, may be made
to partly surround the sides of the furnace, in addition to covering the top of the
same.
With a boiler constructed in this manner, a circulation of water, directly over
the roof of the furnace crown towards the central or other open space, commences
whenever the fire is lighted. And as the heat increases the circulation becomes
more rapid, until with a hot fire, a violent stream of water washes over the furnace
top, and pours up the central or other space or spaces, until when meeting with its
deflector, or with the submerged smokebox, or with the top of the boiler, it is
thereby compelled to spread laterally amongst and throughout the tubes. So that
the lower part of the tubes are thus first washed transversely with a rapid current
advancing towards the central or other open space, and are then again washed
transversely by the same current returning from the central or other open space
towards the outer part of the boiler.
The violent rush of water upwards through the central or other hole of the
circulating plate, also induces, by means of its lateral action, a current of water to
pass over the top of the circulating, plate, in an inward direction amongst the tubes.
By this means the flat top of the furnace crown is kept free from any injurious
amount of deposit, with the consequence that the fire tubes can thereby be placed
much closer than usual. So that by means of my invention, a vertical steam boiler
of this class, can be made much more powerful for any given size, or weight, than
has hitherto been prácticable. And as the firetubes can be, made smaller in
diameter than usual, and as the heat can be very effectually abstracted from them
by the rapid flow of water, the upper part of the tubes which projects above the
water, does not burn away in the rapid manner that is usual with ordinary boilers.
In order that this my invention may be more clearly understood, I have attached
to this description four sheets of explanatory drawings, numbered, Sheet 1, 2, 3,
and 4 respectively.

page_text: Sheet 1. This shows a vertical section of one form of my improved boiler, in
which is seen the firebox below, and the firetubes rising upwards, with an open
space in the center, to the smokebox at the top. The letter C points to the cir-
culating plate. The letter B to the open water space. The letter A to the
deflector. And the letter D shows where the water enters under the circulating
plate, and the arrow-lines show the course that the current takes when the fire is
in action-that is, first inwards over the furnace top, then upwards in the center
on the boiler, and then outwards amongst the tubes.
Sheet 2. This shows a vertical section of another form on my improved boiler,
with the firebox below, and the firetubes rising upwards from it to a smokebox at
the top. It also shows the circulating plate at C, over the furnace; but the
central water space at B, is without a deflector, so that the ascending current of
water, which enters at D, then rises right up to the top of the boiler and disperses
laterally amongst the tubes, where it becomes vaporised and passes away as steam
towards the outlet. This action causes the boiler to produce more steam than
when a deflector is used, and also prevents the upper portion of the tubes from
becoming overheated; so that the whole of the tube surface is then, to some extent,
utilised for producing steam, and is all protected, more or less, by water from
burning away.
And the arrow-lines show the course that the current takes when
the fire is in action-that is, first inwards over the furnace top, then upwards in the
center of the boiler, and then outwards amongst the tubes.
Sheet 3. This shows a form of my improved boiler with a submerged smokebox,
for the purpose of keeping the tubes entirely under water. The circulating plate
as shown at C; the central water space at B; and the place where the water enters
under the circulating plate at D. And the arrow-lines show the course that the
current takes when the fire is in action--that is, first inwards over the furnace top,
then upwards in the center on the boiler, and then outwards amongst the tubes.
Sheet 4. This shows a section of one of my improved boilers with a number of
small discharge holes through the circulating plate amongst the tubes, instead of
a single large opening. The circulating plate is shown at C; two of the various
open spaces amongst the tubes are shown at 13, 13; the place where the current of
water enters under the circulating plate is shown at D; and the arrow-lines show
the direction that the current takes when the fire is in action that is, first inwards
over the tube plate, and then dispersing upwards amongst the tubes.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is:-
1. A steam boiler constructed substantially as herein before described or as
illustrated in the drawings.
2. An arrangement of furnace and firetubes and water circulating plate for steam
boilers, substantially as described or illustrated.
3. A steam boiler having a furnace below with firetubes rising from its roof and
a circulating plate over the furnace crown constructed to convey a current of water
inwards over the furnace top and then upwards within and amongst the firetube
water spaces.
4. The improved water circulating plate for vertical firetube steam boilers.
13
ALL of Wakoma 1902