Improvements in and relating to Steam Boilers.
Year: 1889

page_text: Date of Application, 2nd Apr.,
1889
*Complete Specification Left, 3rd Feb., 1890-Accepted, 8th Mar.,
1890
PROVISIONAL SPECIFICATION.
Improvements in and relating to Steam Boilers.
We HENRY TOMKINS, of 25, Hartington Road, and THOMAS SUDRON AND COMPANY,
Limited, of the Imperial Boiler Works, both in Stockton-on-Tees, in the County
of Durham, Furnace Builder and Boiler Makers respectively, do hereby declare the
nature of this invention to be as follows:-
Our invention relates to boilers of the well known vertical type, in which a dome
_shaped fire box of smaller diameter than the boiler. shell occupies the lower part of the
boiler, in combination with which various arrangements of cross tubes have been
employed to intercept and utilise as large a proportion as possible of the heat from
the fire box, by extending the distance travelled by the hot gases before passing
from the water space to the uptake.
'In boilers as hitherto constructed on this plan, a chamber forming a
an extension
from the fire-box above the dome or crown thereof and towar dsone side of the
boiler shell serves as a combustion chamber, which communicates with the smoke
box, of, the uptake at the opposite side of the boiler by horizontal tubes, through
which the products of combustion or hot gases escape in direct currents to the
chimney.
The object of our invention is to effect improvements in certain respects upon
the various arrangements at present in use for employing horizontal cross tubes for
this purpose, by which improvements we obtain additional heating, surface in the
cross tubes with less interference of the water space or injury. to the boiler shell,
and by which the distance travelled by the hot gases through the water space can
be increased to any useful extent by diverting the currents of the hot gases
from one set of tubes to another in all cases in which the dimensions of the
boiler admit of a sufficient number of tubes being employed for this purpose.
In carrying out our improvements, we provide cross tubes. extending the full
distance across the boiler to the shell on either side, to which the said tubes are
rivetted or otherwise secured, the boiler shell being thus reduced in strength only by
the loss of sectional area due to the openings through the shell into the cross tubes,
the loss of strength thus incurred being made up in part by the flanges of the
tubes, and if necessary by compensating plates extending round the holes so cut out.
The cross tubes communicate towards one end with the combustion chamber and
towards the other with the smoke box, the combustion chamber and 'smoke box being
secured in position to the outside of the boiler shell which froin. this reason is not cut
away for their accomodation; while at the same time the water space is not
encroached upon by the combustion chamber or smoke box, being partially included
within the outside shell of the boiler. In some cases we confine our invention merely
to the improvements offected by transmitting the hot gases through the water space
in tubes extending across the full width of the boiler in the manner as above described,
but in other cases in which the dimensions of the boiler admit of the employment of a
sufficient number of tubes we extend our improvements by prolonging the passage of
the hot gases through the water space by diverting the currents of hot gases from one
set of horizontal tubes to another set. This can be effected by placing the tubes in
separate tiers, one above another, and adding to the combustion chamber and. smoke
box other compartments or sections, so that when the hot gases pass through the
cross tubes of one tier they enter a sectional chamber or compartment outside the
boiler shell, from which they are diverted into another tier of cross tubes to recross

page_text: the water space, and so on according to the height of the boiler, until the hot
gases or products of combustion reach the smoke box from which they escape through
the uptake.
‘G. J. CLARKSON,
Agent for the Applicants.
"
COMPLETE SPECIFICATION.
Improvements in and relating to Steam Boilers.
We, HENRY TOMKINS, of 25, Hartington Road, and THOMAS SUDRON AND COMPANY,
Limited, of the Imperial Boiler Works, both in Stockton-on-Tees, in the County of
Durham, Furnace Builder and Boiler Makers respectively, 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 :-
Our Invention relates to boilers of the well known vertical type in which a dome
shaped fire box of smaller diameter than the boiler shell occupies the lower part of the
boiler, in combination with which various arrangements of cross tubes have been
employed to intercept and utilise as large a proportion as possible of the heat from the
fire box by extending the distance travelled by the hot gases before passing from the
water space to the uptake.
In boilers as hitherto constructed on this plan a chamber forming an extension
from the fire box above the dome or crown thereof and towards one side of the boiler
shell serves as a combustion chamber which communicates with the smoke box of the
uptake at the opposite side of the boiler by horizontal tubes through which the
products of combustion or hot gases escape in direct currents to the chimney.
The object of our invention is to effect improvements in certain respects upon the
various arrangements at present in use for employing horizontal cross tubes for this
purpose, by which improvements we obtain the additional heating surface derived
from the cross tubes with less interference of the water space or weakening of the
boiler shell, and by which the distance travelled by the hot gases through the water
space can be increased to any useful extent by diverting the currents of the hot gases
from one set of tubes to another in all cases in which the dimensions of the boiler-
admit of a sufficient number of tubes being employed for this purpose.
And in order that our invention may be fully understood and carried into effect
we will now describe the same with reference to the accompanying drawings, in
which Figure 1 is a view partially in section of a boiler constructed according to our
invention, and Figure 2 is a corresponding sectional view in plan taken on line A A
of Figure 1. In carrying out our improvements we provide cross tubes a b c,
extending the full distance across the boiler to the shell on either side, to which the
said cross tubes are rivetted or otherwise secured, the boiler shell being thus reduced
in strength only by the loss of sectional area due to the openings through the shell
into the cross tubes, the loss of strength thus incurred being made up in part by the
flanges of the tubes and if necessary by compensating plates extending round the
holes cut out. In the figures the boiler is shown provided with three tiers of cross
tubes a b and c, through which the hot gases or products of combustion pass in
sinuous or reversed currents from the combustion chamber d to the smoke box e;
f and
being communicating chambers from one tier of cross tubes to the next tier
above, so that where three tiers of cross tubes are used the hot gases pass from the
combustion chamber d through the tubes a into the chamber f, and from the chamber
in the opposite direction through the tubes 6 into chamber g, from which they pass
through tubes c into the smoke box e. The number of tiers of cross tubes provided
in a boiler of course depends on the depth of water space available above the furnace
crown, and two tiers of cross tubes might be provided instead of three, in which case

page_text: the smoke box e would take the place of the chamber g shown in the drawings, the
highest tier of cross tubes c being dispensed with; where only one set of cross tubes
is provided in the boiler for want of sufficient depth of water space for more, the
ordinary arrangement of a combustion chamber and smoke.box at opposite parts of
the boiler shell would only be required.
Where only one set of cross tubes are provided leading direct from the combustion
chamber to the smoke box, our invention is confined to the improvements effected by
employing cross tubes above the furnace by which the communication from the
combustion chamber to the smoke box is effected without cutting away the boiler
shell to partially include either the combustion chamber or the sinoke box, but where
a sufficient number of tubes can be provided to divert the currents from one side of
the boiler to the other in the manner herein before described, additional heating surface
is obtained and the heat from the furnace more thoroughly intercepted in its passage
to the smoke box and uptake.
Although it is preferable to obtain the diversion of the currents of the hot gases
through the water space by arranging the tubes in tiers, the direction of the said
currents being reversed in each tier, yet it is obvious that where the tubes are all
arranged on the same level by providing chambers communicating from one cross
tube to another, or two cross tubes to two others as the case may be the currents
of hot gases could be similarly diverted.
Having now particularly described, and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
Firstly In vertical steam boilers arranging the cross tubes to communicate
directly between the combustion chamber and smoke box by extending them across
the full width of the boiler to be connected with or without compensating plates
directly to the boiler shell, substantially as and for the purposes as described with
reference to the accompanying drawings.
Secondly-In vertical boilers arranging the cross tubes in tiers or sets communi-
cating with the combustion chamber and smoke box and with each other for diverting
or reversing the currents of hot gases, which tubes are connected with or without
compensating plates directly to the boiler shell, substantially as described with reference
to the accompanying drawings.
100
1000
Dated this ITSE day
of February 1890.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicants.