Improvements in Steam Generators and Water Heating Boilers.
Year: 1894

page_text: Date of Application, 14th Aug., 1894
Complete Specification Left, 14th May, 1895-Accepted, 29th June, 1895
PROVISIONAL SPECIFICATION.
Improvements in Steam Generators and Water Heating Boilers.
I, RICHARD WATSON MEWES, of 29, Durham Road, Blackhill, in the County
of Durham, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention is applicable to several types of steam generators and water heating
boilers and relates to the arrangement and construction of the fire box or furnace
which will in all cases be completely surrounded by water. Fire bars are dispensed
with, the fuel resting upon the bottom of the furnace and air introduced through
tubes which are distributed over the entire bottom surface and pass through a
water space between the bottom of the furnace and the bottom of the shell and
opening into the ash-pit, their ends being either screwed or expanded in the plates.
The fire is supplied with fuel and stoked through the ordinary fire holes, and the
refuse ashes fall through the tubes into the ash-pit or ash-pan. These tubes may
be conical, the smaller ends being next the fire, to facilitate the descent of the
ashes but I prefer to make them parallel and to ferrule the ends next the fire.
The bottom of the furnace or fire-box and the water space below will be formed
concave internally so that the water heated or steam generated may more readily
escape into and through the surrounding water space around the fire-box as well as
to give greater strength though the latter requirement will be obtained by the
tubes themselves acting as stays. The fire-box in vertical boilers may taper
upwards to the crown and may have cross water tubes as usual in such boilers and
the crown may be semicircular or convex outward with a central flue passing
through the shell to receive the chimney or preferably, instead of central flue, a
number of fire tubes may pass from the crown through the water and steam spaces
to the chimney in which case the crown of the fire box and the top of the shell,
forming the tube plates, will be preferably flat, the tubes acting also as stays. In
boilers having horizontal tubes, as in the locomotive type, the fire box will
preferably have a flat tube plate to receive the ends of the tubes which will then
pass through the boiler shell to a front tube plate and open into the smoke box
and the fire box sides, back and top may be either circular, or approximately
circular, or may be flat and stayed as in locomotive fire boxes. In horizontal
boilers, such as the Cornish or Lancashire types, the air tubes will be distributed
over the semi-circular bottom of the furnace portion of the internal flues passing
through the water space into an ash-pit below in the boiler seating. For water
heating boilers, as applied for various purposes, I have found by an experimental
boiler that the boiling of the water is very rapid owing to the large heating surface
of the bottom being in immediate contact with the burning fuel and the air being
so thoroughly distributed amongst the fuel, and I anticipate that in steam boilers a
considerable increase of evaporation will be effected from this surface and the
absence of fire bars relieves the boiler of a very considerable weight apart from
the expense and trouble of replacing worn out or defective bars.
Dated this 14th day of August 1894.

page_text: Improvements in Steam Generators and Water Heating Boilers.
I, RICHARD WATSON MEWES, of 29 Durham Road, Blackhill, in the County
of Durhain, 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 is applicable to several types of steam generators and water heating
boilers, and relates to the arrangement and construction of the fire box or furnace
which will, in all cases, be completely surrounded by water. Fire bars are
dispensed with, the fuel resting upon the bottom of the furnace and air introduced
through tubes which are distributed over the entire bottom surface and pass
through a water space between the bottom of the furnace and the bottom of the
shell and opening into the ash pit, their ends being either screwed or expanded in
the plates. The fire is supplied with fuel and stoked through the ordinary fire
holes, and the refuse ashes fall through the tubes into the ash pit or ash pan.
These tubes may be conical, the smaller ends being next the fire, to facilitate the
descent of the ashes, but prefer to make them parallel and to ferrule the ends
next the fire. The bottom of the furnace or fire box and the water space below
will be formed concave internally, so that the water heated or steam generated may
more readily escape into and through the surrounding water, as well as to give
greater strength, though the latter requirement will be obtained by the tubes
themselves acting as stays. The fire box in vertical boilers may taper upwards to
the crown and may have cross water tubes, as usual in such boilers, and the crown
may be semicircular or convex outward with a central flue passing through the
shell to receive the chimney or preferably, instead of a central flue, a number of fire
tubes may pass from the crown through the water and steam spaces to the chimney
in which case the crown of the fire box and the top of the shell, forming the tube
plates, will be preferably flat, the tubes acting also as stays. In boilers having
horizontal tubes, as in the locomotive type, the fire box will preferably have a flat
tube plate to receive the ends of the tubes which will then pass through the boiler
shell to a front tube plate and open into the smoke box, and the fire box sides,
back and top may be either circular, or approximately circular, or may be flat and
stayed as in locomotive fire boxes. In horizontal boilers, such as the Cornish or
Lancashire types, the air tubes will be distributed over the semicircular bottom of
the furnace portion of the internal flues passing through the water space into an ash
pit below in the boiler seating. For water heating boilers, as applied for various
purposes, have found by an experimental boiler that the boiling of the water is
very rapid owing to the large heating surface of the bottom being in immediate
contact with the burning fuel and the air being so thoroughly distributed amongst
the fuel, and I anticipate that in steam boilers a considerable increase of evaporation
will be effected from this surface, and the absence of fire bars relieves the boiler of
a very considerable weight apart from the expense and trouble of replacing worn
out or defective bars.
1
DESCRIPTION OF DRAWINGS.
On the accompanying 2 sheets of drawings my invention is shewn as applied to
different types of boilers.
Figs. 1 and 2, Sheet 1, shew a sectional elevation and sectional plan of a vertical
auxiliary boiler.
Figs. 3, 4, and 5 shew respectively a longitudinal section, sectional end view, and
sectional plan of the fire box end of a boiler of the locomotive type, and

page_text: Figs. 6 and 7 a transverse and longitudinal section of the furnace end of a
boiler with two flues leading from one furnace common to both resembling the
Lancashire types.
On Sheet 2,
:
Fig. 8, is a transverse section and Fig. 9 a longitudinal section of the furnace
end of Cornish type of boiler, and
Figs. 10 and 11 shew respectively a vertical section and balf sectional plan of an
auxiliary boiler of the "Meredith and "Cochrane " types.
The adaptation to other types of boilers will be readily understood from the
examples given.
The same letters refer to corresponding parts on all the figs.
Referring to Figs. 1 and 2, A. is the boiler shell, B. the furnace or fire box, so
constructed relatively to the shell as to leave a water space C. between them of
convex form outward to facilitate the escape of steam generated by the heat of the
fuel transmitted through the furnace bottom. This water space C is traversed by
a number of tubes D, which supply air to the furnace for the combustion of the
fuel which lies upon the furnace bottom without fire bars. These air tubes are
either screwed or expanded into the two plates and may be ferruled at their upper
ends so as to facilitate the discharge of ashes into the ash pit below, and from the
crown tube plate of the furnace fire tubes E, forming flues, extend through the
water and steam space to a tube plate which forms the top of the shell upon which
a smoke box is formed leading to the chimney. Across the furnace is a transverse
conical water tube F. to spread the flame and gases increase the heating effect
and promote circulation of the water. Additional air tubes G. may be inserted
between the sheil and furnace above the fuel to supply air for consuming smoke
with certain kinds of fuel.
Referring to Figs. 3, 4, and 5, the outer vertical shell A. and the furnace or fire
box B. are cylindrical, the crowns of each being partially domed so as to dispense with
staying, except for very high pressures, and the back of the furnace is formed so as
to provide a flat tube plate for the ends of the horizontal fire tubes E. The bottom
of the furnace B. and of the shell A. are also curved so as to form a convex water
space G. traversed by the air tubes D.
Referring to Figs. 6 and 7, A. is the shell, B. the furnace forming an oval
chamber, from which two fire flues E. traverse the length of the shell, and the
furnace is stayed by a conical water tube F. The water space C. beneath is
traversed by the air supply tubes D. which in this case are shewn conical and open
into the ash pit below.
As applied to boilers of the marine type with two or more furnaces an ash
chamber or chambers will be constructed in the seating of the boiler into which the
series of air tubes will open, and bars being dispensed with the furnaces may be of
much smaller diameter as also may the shell of the boiler.
Referring to Sheet 2, Figs. 8 and 9, A. is the boiler shell, B. the furnace of
slightly oval section at bottom to suit the fixing of the air tubes D. through the
water space C. E. is a single flue from the furnace extending through the shell. On
Figs. 10 and 11, A. is the boiler shell, B. the furnace, the back of which is gathered
inward to provide a flat tube plate, É. are short horizontal flue tubes opening into
a loose smoke box attached to the shell, C. is the convex bottom water space
through which the air tubes D. pass, and open into the ash pit formed by the
extension of the shell plates.
Having now particularly described and ascertained the nature of said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
The improvements in steam generators and water heating boilers, consisting in
providing, between the furnace bottoms and the outer shell, a number of air inlets
passing through a water space and opening into an external ash pit and into the
furnace, the spaces between said air inlets carrying the fuel on the furnace bottom

page_text: and the ashes falling through the air inlets; provision being made for introducing
air above the fuel when required, to assist combustion and prevent smoke ;
substantially as described and in some forms shewn on drawings.
Dated this 14th day of Mov 1805
T. J. DANSON, F. Inst. P.A.,
Chartered Patent Agent, Agent for Applicant.