Improvements in internally
Year: 1887

page_text: Date of Application, 1st Nov., 1887
Specification Accepted, 2nd Dec., 1887
Improvements in internally
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention which has been communi-
cated to me from abroad by George H. Sellers of Ridley Park in the County of
Delaware and Stato of Pennsylvania Engineer and William Malam of Edge Moor in
the County of Newcastle and State of Delaware, Engineer both in the United States
of America and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
I will describe this Invention with reference to the accompanying drawings in
which Figure 1 represents a vertical longitudinal section through the centre of the flue
of a Galloway Boiler embodying the improvements constituting the present Invention.
Figure 2 is a vertical cross section of the same on the line A. B. Figure 3, looking
towards the furnace end and Figure 3 is a horizontal cross section of the same Boiler
shewing the exterior of the flue and its two furnaces.
As these improvements relate more particularly to what is known as the Galloway
Boiler the drawings represent this form of Boiler but the said Improvements are
applicable to any Boiler having conical vertical water tubes in a horizontal internal
flue.
A marked characteristic of the Galloway Boiler is the long combustion chamber or
flue common to its two furnaces which chamber is provided with conical vertical
water tubes so placed that every part of its interior is accessible for examination and
repair whilst the exterior is so shaped as to afford space for a like purpose between
the flue and the outer shell of the boiler.
In the construction of this Boiler the internal flue which contains the vertical
water tubes has been heretofore composed of a series of zones united at their ends by
circumferential seams of rivets, each zone was formed of four plates bent transversely
to the plate to conform to the shape of a transverse section of the flue and united at
their ends by four longitudinal seams of rivets so that the flue was, like the exterior
shell of the boiler provided with longitudinal and circumferential seams of rivets and
thus constructed the zones determined the number and position of the vertical tubes
as it was necessary that the flanges of the tubos should not overlap the rivet seams
ونم

page_text: which united the zones while the requirement of accessibility to all parts of the
interior limited location in that direction..
-
The top and bottom of this flue are segments of a circle struck from a common
centre below the flue and the two sides are hemispherical. The circumferential rivet
seams strengthen the hemispherical plates to resist the tendency to collapse under the
external pressure to which they were subjected in service, but oven thus strengthened
these sides are the weakest part of the flue while the number of plates which composed
the whole flue render its construction both difficult and expensive.
In forming the hemispherical sides of the flue it has been the usual practice
heretofore to construct two or three pockets in each side the longitudinal axis across
the flue and with circular or oval outline on this axis, which pockets projected towards
the vertical water tubes to obstruct the direct outflow of the products of combustion
along the outer sides of the rows of vertical water tubes although badly formed for
the purpose these pockets served also to increase to a small extent the area of water
circulation between the outside of the flue and the inside of the Boiler Shell but
notwithstanding this increased area it has been found desirable to reduce the width
of this flue below that of the two circular furnaces. with which it is connected, to
provide sufficient area for the circulation of the water and this renders the connection
-with the furnaces more difficult than it would be if the width of the fluo and the
furnaces were the same.
It is the object of this Invention to simplify the construction of the internal flue for
such boilers to increase its width and at the same time to increase the area for water
circulation around it, to decrease the space for the direct ontflow of the products of
combustion to equalize its strength and add to its heating surface, and to these ends
the invention consists in an internal boiler fiue composed of four platos united by
longitudinal rivet scams without intermediate circumferential rivet seams and
-provided with conical vertical water tubes; and it further consists of an internal boiler
Aue without intermediate circumferential rivet seams, and provided with conical
vertical water tubes, and hemispherical sides corrugated conformably with the
longitudinal spacing of the outer rows of such vertical tubes.
It will be
In order to show clearly tho means employed to accomplish the objects of this
Invention I refer to figure 1 of the drawings which represents a vertical section
through the longitudinal axis of a Galloway Boiler between its two furnaces in
which C is one of the furnaces as seen from its exterior D, I), is the combustion
chamber or flue and E, E, E, are the conical vertical water tubes.
observed that these water tubes have their upper flanges above the top plate F of the
fluo which plate extends the whole length of the flue and that their bottom flanges
are above the bottom plate G which also extends the whole length of the flue. To
accomplish this the water tubo is made conical the outside of the upper end having
the same diameter as the flange of the lower end; the arrangement of the tubes can
be seen in Figure 3 and it must be noted that there is no room between the upper
flanges of any row of tubes for a rivet seam such as would be required if this flue had
been constructed of zones of plates united by circumferential seains as heretofore.
As shewn the vertical tubes are evenly spaced throughout the flue as heretofore in
each zone but the loss of space between the zones is avoided which may be utilized to
increase the number of tubes say by about ten per cent. or the spaces between the
tubes may be increased to render the interior more convenient of access.
The direction and depth of the corrugations in the side plates H H are shewn in
Figure 2 the outline in the longitudinal axis is straight to facilitate the water
circulation and the spacing or distance from centre to centre is shewn in Figure 3 as
also the shape of their cross section which is represented by dotted lines. These side
plates are like the top and bottom plates the full length of the flue but before they
are corrugated they are longer, after corrugation they are trimmed if necessary to
the proper length. The uniform spacing of the vertical tubes enables the side plates
to be corrugated with one set of dies which could not be done if the spacing of the
tubes were irregular as heretofore because the corrugations must conform to the
position of the vertical tubes in the outer rows to afford the necessary room for.

page_text: examination and repair when required. All of the plates F, G, H, H, are bent to the
proper curvature as shewn in Figure 2, and the top and bottom plates are punched to
receive the vertical tubes. The four plates are then rivetted together at the four
longitudinal seams a a a a after which the vertical tubes are rivetted in place.
As thus constructed the number of rivets required for a flue is reduced about
22 per cent. while the fitting is greatly simplified and the width of the flue that is to
say the largest lateral dimension can be made equal to that of the two furnaces while
the deep and wide corrugations will afford increased room for water circulation
between the flue and the outer shell of the boiler and at the same time decrease the
space for the direct outflow of the products of combustion, they will also add very
materially to the strength of the hemispherical sides of the flue (heretofore its
weakest part) while they make an important addition to their heating surface and
render their exterior and the interior of the outer shell more accessible than heretofore
without impairing in this particular the interior of the flue.
Having now described and particularly ascertained the nature of this Invention
and in what manner the same is to be performed we declare that what we claim is:
First. In internally heated steam generators an internal boiler flue composed of
but four plates united by longitudinal Rivet seams without intermediate circum-
ferential rivet seams and provided with conical vertical water tubes substantially as
herein before described.
Second. In internally heated steam Generators an internal boiler flue provided
with conical vertical water tubes and hemispherical sides the said sides being
corrugated conformably with the longitudinal spacing of the outer rows of such
vertical tubes substantially as and for the purposes herein before set forth.
Third. In internally heated steam generators an internal boiler flue composed of
but four plates united by longitudinal rivet seams without intermediate circum-
ferential rivet seams and provided with conical vertical water tubes and hemispherical
sides the said sides being corrugated conformably with the longitudinal spacing of
the outer rows of such vertical tubes substantially as and for the purposes herein-
before set forth.
Dth t
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