Improvements in Water-tube Steam Boilers.
Year: 1895

page_text: Date of Application, 7th June, 1895-Accepted, 2nd Nov., 1895
COMPLETE SPECIFICATION.
Improvements in Water-tube Steam Boilers.
DAVID DAVIES of Crumlin Viaduct, near Newport, in the County of Monmouth,
Mechanical 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 :-
The object of this invention is to construct water-tube steam boilers, in separate
units or divisions each unit in each group being a single steam generator, receiving
its feed-water from the bottom of, and delivering its steam back to the top of a
cylindrical steam receiver, but is so arranged that a series of such units may be
coupled, or connected together in separate groups and worked jointly in collective
groups, each group being readily disconnected by simply turning the three-way
water cock and shutting the steam stop valve and so permit the fire for one group to
be withdrawn, and the water to be blown out of the separate units through blow-off
cock without interfering with the working of the other group, thus forming what
I term a sectional water-tube steam boiler, which arrangement presents a much
more extensive heating surface, and as the hot gases are caused to circulate through
flue spaces formed between the tubes, in separate units it thereby economises fuel.
It also permits each tube to be examined and readily cleaned, both inside and
outside, and in cases of emergency any single tube may be plugged at either end,
and it reduces the time and labour required for cleaning, repairs, and the substitution
of new for worn out or defective tubes.
DRAWING
Figure 6. is half elevation of my improved unit water-tube steam boiler, shewing
inside straight tubes.
Figure 7. is half elevation of same unit section shewing continuous wall of tubes
formed with tubes bent at one end only.
Figure 8. is a vertical section of same through line E. E.
Figure 9. is sectional half plan through line F. F.
Figure 10. is sectional half plan through line G. G.

page_text: DRAWING No. 5.
Figure 14. is side view of Figure 12, shewing the mode of connecting the separate
sectional water-tube boilers with the steam receiver.
"
In the construction of these separate unit sectional steam boilers A. which are
improvements on Patent granted to me in 1874 No. 88, I make the separate "unit
sections out of one top steam chamber F, and one bottom water chamber G, con-
nected by a series of any number of straight tubes H, which are expanded into the flat
tube plate I. of each chamber. These top steam, and bottom water chambers,
are each the same shape and size, and are constructed out of one flat wrought
iron, or steel tube plate I. (in which the ends of the tubes are expanded) connected
by screwed bolts and nuts y to four quadrant shape, cast, or mild steel chamber
plates K.
When mild steel, or wrought iron, is used for these quadrant shape
plates K, they are pressed in dies to a uniform shape under hydraulic (or other)
pressure, and by removing any one of these quadrant shape chamber plates K.
it gives direct access to one half the ends of the tubes for the purpose of cleaning
or plugging and to two sixths of the tubes for renewing in that end of the chamber.
The tubes may be arranged in, one two, three or more rows, so as to form separate
flue spaces between them, and the hot gases can be caused to traverse up one
side, and down the other side, of any row of tubes, by bolting cast or wrought iron,
diaphragm plates L. (of any shorter length than the tubes) between any row of
tubes, so as to form flue spaces at either top or bottom, as may be required for
final escape of gases from the last flue into the uptake M 4.
"
Sheet 2. Figures 7. 8 and 10. show modification. When it is desired to make
any of the unit sections" for inside or outside, with a continuous row, or wall of
tubes touching each other to increase the heating surface, to form a flue, or to
prevent the heat of fire or gases passing outside of boiler, I make the top steam
chamber, and the bottom water chamber, trough shape M with one central bottom N.
having two vertical sides O. each with a horizontal flange P. to form tube plate at
right angles to vertical side plates, on the right and left hand side, and I fix the
middle row of short straight tubes Q into the central bottoms N which form the
tube plates for this central row, and I expand the tubes therein. After which I
place the row of long straight tubes on the left hand into the horizontal flange D of the
trough forming the tube plates, and I expand the tubes therein. I next fix the row
: of outside tubes S. on the right hand side, which are bent at one end only with their
bent ends inserted alternately in the vertical outsides O. of the top chamber, and in
the vertical outside O. of the bottom chamber, and I expand the bent ends of the tubes
therein, thus leaving the straight ends of these bent tubes to pass freely through the
horizontal flanges P. of trough shape chambers forming the tube plates, and in
which they are finally expanded, so forming a continuous wall of tubes by
bending them at one end only, and thus securing practical freedom for adjustment
in fixing each tube in its place, and also providing direct access into the tubes for
cleaning, and facility for changing tubes, as the movable cover quadrant shape
plates K. of the chambers and their separate ends W. are connected with screwed
bolts and nuts g, passing through the outside edges of the horizontal flanges of the
trough shape chambers. These "unit sections receive their feed-water through
independent pipes T, as shown on Sheet 3 and 5, which are connected to the
main horizontal feed-water supply pipe U. and this horizontal pipe U. receives its

page_text: supply direct through the vertical down pipes V. leading from the bottom of the
cylindrical receiver B. through the smaller intermediate receivers B 5 and B 6.
which are united, as shewn in Figures 11 and 13, and it is controlled for
either group, by the three-way water cock C, and as the feed enters at the
bottom corner of the unit sections, the water is thus caused to traverse
in contact with the whole interior surface of the tubes before the steam is
liberated into the steam space at top of unit sections from where it is conveyed by
pipes Y to steam collecting pipe Z. which is fitted with stop valve D. controling
the admission of steam to cylindrical receiver B. from right and left hand group of
united sections.
And the receiver B is fitted with safety valves B 1. main stop valve B 2. check
valve B 3. water gauge glasses, and try cocks for regulating the working of same.
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.) Making the steam and water chambers of the sectional water-tube boilers,
with any number of quadrant shape cast steel plates, or from mild steel, or wrought
iron plates, pressed to shape in dies under hydraulic (or other) pressure.
(2.) Making sectional water-tube boilers with a continuous wall of tubes, set in
line touching each other, out of tubes bent at one end only.
(3.) The construction of separate sections, and the formation of sectional water-
tube steam boilers, with a number of such separate and independent sections grouped
and united together, substantially as herein described and shewn in drawings.
Dated thin 7th 1 of Jun 1905
DAVID DAVIES,
Crumlin Viaduct, near Newport, Monmouthshire.