Improvements in Water-tube Boilers.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Water-tube Boilers.
I, GEORGE GATTON MELHUISH HARDINGHAM, of Clun House, Surrey Street, in
the County of London, Civil Engineer and Chartered Patent Agent, do hereby
declare the nature of this invention (a communication from abroad from Edwin
Dolby and Arthur Charles Auden, both residing temporarily at Jeppestown,
near Johannesburg, in the South African Republic, Engineers), to be as follows:-
This invention relates to an improved construction of vertical boiler of the
water-tube type. adapted for use with launches, motorcars, fire-engines, cranes and
the like, and wherein quick-steaming qualities and lightness are required in con-
junction with efficiency, safety and ready accessibility for repairs.
According to this invention, the boiler consists of an annular water chamber
within which the fire-grate is arranged and whence a series of heating tubes
extend upwards, these being arranged in such a manner as to form a conical com-
bustion chamber surmounted by a water and steam-drum with which the upper
extremities of the heating tubes communicate. The heating tubes which may
comprise several concentric groups as also the water and steam-drum are prefer-
ably enclosed within a double casing through which air on its way to the furnace
passes and becomes heated.
The annular water chamber may be formed with a gap opposite which the ash-
pit door is arranged. The space above the gap, not being occupied by heating
tubes, may be occupied, first, by the fire-door and, secondly, by a feed-water
heater. The proper circulation of the heated products of combustion amongst the
water-tubes may be assisted by means of a baffle-plate suspended at a suitable
height within the conical combustion chamber before referred to.
G. G. M. HARDINGHAM.
Improvements in water-tube boners.
I, GEORGE GATTON MELHUISH HARDINGHAM, of Clun House, Surrey Street, in
the County of London, Civil Engineer and Chartered Patent Agent, do hereby
declare the nature of this invention (a communication from abroad from Edwin
Dolby and Arthur Charles Auden, both residing temporarily at Jeppestown,
near Johannesburg, in the South African Republic, Engineers,) and in what

page_text: manner the same is to be performed to be particularly described and ascertained
in and by the following statement: —
This invention relates to an improved construction of vertical boiler of the
water-tube type adapted for use with launches, motorcars, fire-engines, cranes and
the like, and wherein quick-steaming qualities and lightness are required in con-
junction with efficiency, safety and ready accessibility for repairs.
The accompanying drawings illustrate a steam-generator constructed according
to the present invention. Fig. 1 is a vertical section, Fig. 2 a half plan view in
transverse section with the casing removed, the section being taken on the line a―y
in Fig. 1. Fig. 3 is a front elevation and Fig. 4 a corresponding half plan.
According to this invention, the boiler consists of an annular water-chamber A
within which the fire-grate B is arranged and whence a series of heating tubes C,
arranged in several concentric circles, extend upwards, these being arranged in
such a manner as to form a conical combustion chamber D surmounted by a
water and steam chamber E with which the upper extremities of the heating
tubes C communicate. e is a baffle plate whereby pruning and foaming are
obviated. The heating tubes, as also the water and steam chamber, are preferably
enclosed within a double casing F, through which air is caused to circulate with
a view to preventing the outer casing becoming overheated. The outer casing
may, however, be arranged so as to enclose the annular water-chamber A, as well
as the heating tubes C and water and steam chamber E, so that air, on its way
to the furnace, may pass downwards through such double casing and become
heated.
Above the annular water-chamber A in the front of the structure there is a
space not occupied by heating tubes. In this space is arranged a feed-water
heater G formed with a gap H to which the fire-door (not shown) is fitted. The
gap or opening for affording access to the fire may be formed in the annular water-
chamber, but the arrangement illustrated is preferred; as resulting in a stronger
construction and affording greater depth for the fire. The feed-water heater
communicates with the water and steam chamber E by means of the pipe g and
may be fed through either of the nozzles g. 92 g² are plugged orifices through
which any sediment subsiding from the feed-water may be discharged. It will,
however, be obvious, that the feed-water heater may be connected with the annular
water-chamber or with the latter and the water and steam chamber. The circula-
tion of the heated products of combustion amongst the water-tubes C may be
assisted by the addition of a baffle-plate suspended at a suitable height within the
conical combustion chamber 1) in the usual manner. L is the ash pan and is
furnished with a discharge-door 7 which may also be employed as a damper.
By arranging the feed-water heater in the manner described, heat which would
otherwise be wasted is economically employed in providing a hot feed; the water
being at the same time freed from earthy impurities which become solidified at
a temperature approaching boiling point.
or of
The heating tubes being straight and uniform the process of cleaning
renewing the same is greatly facilitated. Moreover, the peculiar construction of
the fire-box enables ferrules or tube-shields to be dispensed with, as the fire does
not come into direct contact with the tube-ends.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I claim :-
1. A steam-generator constructed substantially as herein described and com-
prising a group of water-tubes arranged to form a conical combustion chamber
and connecting an annular water-chamber below with a water and steam chamber
above, the heated products of combustion passing outwards between the tubes
and around the water and steam chamber.
2. In a steam-generator of the kind referred to in the preceding claiming
clause, a conical combustion chamber formed for the greater part by a group of

page_text: straight but inclined tubes, the side of the chamber being completed by a feed-
water heater, substantially as herein described.
3. The improved steam-generator constructed substantially as described with
reference to the accompanying drawings.
G. G. M. HARDINGHAM.