Improvements in Water Tube Steam Boilers.
Year: 1896

page_text: Date of Application, 19th Mar., 1896-Accepted, 13th Mar., 1897
COMPLETE SPECIFICATION.
Improvements in Water Tube Steam Boilers.
I, ALFRED FERNANDEZ YARROW, of Isle of Dogs. Poplar, in the County of London;
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 :--
My invention relates to the construction and arrangement of a water tube steam
boiler in such a manner as to give ready access for cleaning the tubes, or for removing
and replacing a defective tube, and, in cases where the fire is of considerable width,
to provide an additional supply of air for combustion.
I shall describe a boiler according to my present invention and certain modifications
thereof referring to the accompanying drawings.
Fig. 1 is a transverse section and Fig. 2 is a plan of a boiler having a fire grate of.
moderate width.
Fig. 3 is a part transverse section of a boiler of like kind having a fire grate of
considerable width and provided with an additional air supply and
Fig. 4 is a part transverse section with a modified arrangement of air supply.
Fig. 5 is a transverse section of a boiler having tubes connecting the steam and
water chamber A with water chambers W below, shewing how tubes can be removed
or replaced;
Figs. 6, 7 and 8 are sections shewing rows of holes made in the plates for this
purpose.
Referring first to Figs. 1 and 2, I joint to the steam and water chamber A a
number of inclined tubes B like those known as "Field " tubes, having their lower ends
closed and provided with internal partitions or smaller tubes for promoting circulation
of the water. Besides the sets of side tubes B, I joint also to the rear part of the
chamber A another set of tubes C which form as it were the end of the fire chamber,.
being interposed between the fire and the rear wall D of the casing.
I arrange the rows of the tubes B in pairs, each pair consisting of two rows near
each other but so far apart from the next similar pair of rows that there is room for
clearing the tubes or for removing and replacing a tube. The rows may be arranged
either diagonally as shewn in Fig. 2 or at right angles to the longitudinal axis of the
boiler. By using tubes with fins or ribs projecting from their sides for the parts E
of the inner rows, I form these parts as walls, preventing the flames and hot gases
from passing, except through the front parts of the inner rows of tubes and then
back through all the rows of tubes to the two uptakes F F which are led up at the
rear obliquely to chimney G.
As shewn in Fig. 3, when the fire grate has to be of considerable width, I build
in the middle of it a hollow partition H of refractory material with lateral openings,
so that air, ascending from the ash pit, can pass out laterally and mix with the.
combustion gases in the fire space.
Instead of building a partition of refractory material, it may, as shewn in Fig. 4
consist of two or more rows of tubes K K extending up from a water chamber W so.
that air can ascend in the space between the rows and pass out through between the.
tubes of the rows into the fire space on each side.
The tubes K K instead of extending up from a water chamber, may be closed at.
their lower ends and provided with internal tubes or partitions to act as "Field"
tubes. Although I have shewn the partition H or rows of tubes K K applied to a
boiler having Field " tubes obviously either of these arrangements for supplying.

page_text: additional air in the fire space may be applied to boilers in which the water tubes,
instead of being closed at the bottom have their lower ends jointed to water chambers
of cylindrical or other form as shewn in Fig. 5.
For facilitating the removing or replacing of a tube, I countersink or recess the
holes in the upper and lower tube plates either on the upper side as in Fig. 6 or on
the underside as in Fig. 8, or on both sides as in Fig. 7, leaving in each case
cylindrical portions T to fit which the tubes are expanded.
When a tube has to be removed it is loosened at the parts T, it can then be raised
a little and moved into a position sufficiently inclined to pass down clear of the water
chamber W.
Obviously the operation may be reversed, the tube being lowered a little from the
upper tube plate and inclined in the recessed hole of the lower tube plate.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. A water tube steam boiler constructed and arranged substantially as described
with reference to Figs. 1 and 2.
2. In a water tube boiler having a wide fire grate, a hollow partition or rows of
tubes arranged along the middle of the fire space, substantially as and for the purpose
set forth.
3. In a water tube boiler, countersinking the holes of the tube plates, substantially
as and for the purpose set forth.
Dated this 19th day of March 1896.
ABEL & IMRAY,
Agents for the Applicant.