Improvements in Steam Generators.
Year: 1895

page_text: Date of Application, on Apr., 1899
Complete Specification Left, 6th Jan., 1896-Accepted, 8th Feb., 1896
Improvements in Steam Generators.
1, EDMUND FREDERICK WAILES, of No. 4 St. Nicholas Buildings, in the City
and County of Newcastle-upon-Tyne, Naval Architect and Engineer, do hereby
declare the nature of this invention to be as follows:-—
This invention is applicable to most types of internally fired boilers, but has
special reference to marine boilers of the multitubular return tube type, to which
the description following is intended to refer.
The improvements which may be adapted to existing boilers consist in
considerably reducing the length of the furnaces to admit of the introduction,
between their back ends and the combustion chamber or "flame-box," of one or
more flues in area proportioned to the grate area, which is also considerably
reduced, and further in the introduction into the combustion chamber or chambers,
at suitable points among the flame and gases, of atmospheric air from the stoke
hole, either under natural or forced draught, through pipes traversing the ash pits
and delivering the air at suitable heights in the combustion chamber or chambers.
The flues will preferably be circular, but may be oval in some cases, and plain,
corrugated, or ribbed and, for ready access to the inside of the bottom parts at the
back end of the boiler for examination or repairs, the bottom of the combustion
chamber may be raised or as in existing boilers, the ordinary form of combustion
chambers preserved.
The advantages of this combination of furnaces and flues, reduced length of fire
grate and the introduction of air into the combustion chambers are as follows,
viz. :-
Reduced but more efficient grate surface, owing to being properly "stoked" and
saving in fire-bars.
More perfect combustion, by the introduction of air into the combustion chamber
to mix with the flame and gases, and the prevention of smoke.
Increased space for access to bottom of the interior of boiler for examination
and repairs.
The cooling surface of the bottom half of the furnace reduced by about one
half.
Accelerated circulation of the water in the boiler, from the lower parts upward,
by the improved distribution of heat from the flues.
Economy of fuel owing to better "stoking," increased and more effective heating
surface, and improved circulation and the more perfect combustion by the
introduction of air amongst the flame and gases.
Dated this 5th day of April 1895.

page_text: COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I, EDMUND FREDERICK WAILES, of No. 4 St. Nicholas' Buildings, in the City
and County of Newcastle-upon-Tyne, Naval Architect and Engineer, do hereby
declare the nature of said invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement-
This invention is applicable to most types of internally fired boilers, but has
special reference to marine, boilers of the multitubular, return tube type; to which
the description following is intended to refer.
.
The improvements which may be adapted to existing boilers consist in
considerably reducing the length of the furnaces to admit of the introduction
between their back ends and the combustion chamber. or "flame-box" of one or
more flues, in area proportioued to the grate area, which is also considerably
reduced, and further in the introduction into the combustion chamber or chambers,
at suitable points. among the flame and gases, of atmospheric air from the stoke-
hole, either under natural, or forced draught, through pipes traversing the ash pits
and delivering the air at suitable heights in the combustion chamber or chambers.
The flues will preferably be circular, but may be oval in some cases, and plain,
corrugated, or ribbed, and, for ready access to the inside of the bottom parts at the
back end of the boiler for examination or repairs, the bottom of the combustion
chamber may be raised or, as in existing boilers, the ordinary form of combustion
chambers preserved.
The advantages of this combination of furnaces and flues, reduced length of fire
grate, and the introduction of air into the combustion chambers are as follows,
viz. —
Reduced but more efficient grate surface owing to being properly "stoked" and
saving in firebars.
More perfect combustion,. by the introduction of air into the combustion
chamber to mix with the flame and guses, and the prevention of smoke.
Increased space for access to bottom of the interior of boiler for examination
and repairs.
The cooling surface of the bottom half of the furnace reduced by about one
half.
Accelerated circulation of the water in the boiler, from the lower parts upward,
by the improved distribution of heat from the flues.
Economy of fuel owing to better "stoking," increased and more effective heating
surface, and improved circulation, and the more perfect combustion by the
introduction of air amongst the flame and gases.
DESCRIPTION OF DRAWINGS.
My invention is illustrated on the accompanying drawings, to an approximate.
scale of one half inch per foot, as applied to a marine boiler of the multitubular
return tube type, having two furnaces with separate combustion chambers, and
shewing various modifications as to the disposition of the flues leading from-the
furnaces to the combustion chambers, and..of the means for supplying air to the
combustion chambers at the outlets of the flues, or through said outlets.
Fig. 1 is a half cross section of the boiler ou the line ab of Fig. 2; and
Fig 1 is a half cross section on the line c-d of Fig. 2.
Fig. 2 is a longitudinal section through one of the furnaces and the single main
flue, having two small flues, one at each side leading from the furnace into the
combustion chamber.
Fig. 3 is a full sectional plan of Figs. 1 and 1ª.
Fig. 4 a longitudinal section through the line a 7. WA

page_text: Fig. 4 is a cross section through one furnace at ef Fig. 4, shewing a
modification with two upper flues B' in which a portion of the flame and gases pass
from the furnace grate downward over the bridge and through one large and two
sinaller flues into the combustion chamber, and this arrangement is preferable
where the length of the boiler admits of it, without unduly contracting the grate
bar surface, or when working under forced draft with reduced grate bar surface.
Fig. 5 shows a section of an arrangement of two flues instead of one large flue.
with two small flues as in Figs. 1 and 2, giving a larger sectional area, in.
proportion to the grate surface, and more heating surface.
The same letters refer to the corresponding parts on all the figs.
Referring to Figs. 1 and 2, A A' are the furnaces, B1, B2, B3, the flues leading
from the furnaces to the combustion chambers CC'. The furnace front D has
formed upon it the "dead-plate" E, upon which rest the front ends of the grate
bars F, made in one length, and at the back end resting upon a shelf G, on which
the bridge H is placed, of fire clay or bricks. A small pipe J. conveys air from.
the ash pit through the water space into the combustion chamber, and also serves
as a means of clearing out the soot accumulated in the combustion chamber, by
introducing a rake from the stokehole, and the mouth of this pipe may be closed or
partially closed at the front end, so as to regulate the quantity of air. This air-
may enter, either under natural or forced draft, and will be warmed in its passage
through the ash pit and through the hot water in the boiler. In addition to this
supply of air I may introduce a sprayer K into each combustion chamber with a
supply pipe L leading from it through the water in bottom of boiler to the front
next the stokehole, and this air may be applied under natural or forced draft in
regulated quantity.
Referring to Figs. 4 and 44, (also to left hand side of Fig. 3 as to the bridge
bracket on Fig. 4) A A' are the furnaces, B'B' are large flues above the bridge H,.
and B, B, and B are smaller flues, below the bridge, over which a portion of the
flame and gases passes downward, and through these flues into the combustion.
chamber, heating the water surrounding them underneath the main flues. Air,.
either under natural or forced draft, may be supplied from the ash pit by passages
being provided in the bridge bracket plate M, which can be closed by a central
sliding door N, operated from the stokehole, and by slotted openings closed by
revolving slotted discs O over the flues B and B. Here the central lower flue B³
serves also as a means of clearing out the soot accumulated in the combustion
chamber, as described with reference to Figs. 1 and 2, an aperture P being
provided in the bridge bracket plate M of sufficient size and corresponding to the
mouth of the central lower flue B³, so that when the sliding door N is withdrawn
into the stokehole a rake may be introduced as previously stated.
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 or boilers of the return multitubular
type, with special reference to marine boilers consisting in interposing between the
furnaces and the combustion chambers one or more fire flues, disposed when more.
than one, either above the furnace grate, below the grate, or partly above and
partly below the grate, with or without provision for supplying air either under
natural or forced draft and heated or not into the combustion chambers, with the
objects hereinbefore stated, constructed and operating substantially as described
and shewn on the accompanying drawings.
Dated this 4th day of January 1896
T. J. DANSON, F. Inst. P.A.,
Newcastle-upon-Tyne, Agent for Applicant..