Flame Tube Steam Boiler
Year: 1886

page_text: Date of Application, 23rd Nov., 1886
Complete Left, 22nd Aug., 1887
Complete Accepted, 23rd Nov., 1887
GEORGE EGGERS of Sudenburg near Magdeburg, in the Empire of Germany,
Engineer do hereby declare the nature of this invention to be as follows :-
My construction of a Flame Tube Steam Boiler differs from those in use that the
proper flame tubes in their longitudinal direction are divided by partition walls into
Hame tube halves between which the water circulates and which are kept by pins or
boiling tubes at a fixed unmovable distance from each other.
These partition walls may be flat or waved form running parallel with each other,
or may approach each other, they can begin at any flame tube connection.
My steam boilers of one or two flame tubes of which each tube is divided by parti-
tion walls in halves, whereby for instance the two flame tube boilers are converted
into a four flame tube boiler.
In the same way this arrangement may be adopted for one flame tube boiler,
whereby it is converted into a two half tube boiler.
The heat goes according to the arrangement of the flues, first through the half
tubes, after that round the outside of the mantel of the boiler and then escapes by
the chimney.
In each of the half pipes grates may be placed and may be constructed either for
coals or any other fuel to be burnt, on plane or step grates for interior or front fire.
The construction allows that the grate is placed in one half tube, the heat passes
through all the half tubes, whereby transmission chambers are formed at the end of
the boiler in order to lead the heat from one half tube into the other.
In consequence of this new construction of the flame tubes having comparatively
a small grate, a considerable greater evaporative power is obtained, than with the
constructions now in use, the water circulates more freely between the partition walls,
and through the larger heat surface of the boiler, which arises through the addition
of the height of the partition walls, to the whole length of the boiler, whereby a
greater useful effect is obtained.
Dated this 23rd day of November 1886.
CARMAN & Co.,
Agents for the Applicant.

page_text: I, GEORGE EGGERS of Sudenburg near Magdeburg in the Empire of Germany
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 relates to that class of steam boilers in which the gases produced in a 5
furnace pass through flues in order to part with their heat.
I endeavour to obtain an increase in the heating surface of these flues, without being
obliged to increase the length of the boiler, or the diameter of the flues.
Fig. 1 shows the boiler in longitudinal section.
Fig. 2 is a cross section on the line A-B.
Fig. 3 is a horizontal section on the line E-F.
Fig. 4 is a cross section on the line C-D.
The boiler here shewn has two flues, but the invention can be equally well applied
to boilers with one flue only, or to boilers with more than two flues. a is the shell
of the boiler, as usually constructed in such boilers; the two flues bb are however
differently constructed from the ordinary arrangement.
They do not consist of a complete cylindrical shell, but they are divided into two
halves by two walls bb, between which the water circulates. These division walls
may be flat or arched, and may run parallel to each other or may approach each
other; they may start from any desired joint of the flue.
The division walls are kept at a fixed unalterable distance apart by means of the
stay-bolts c or other similar means of connection, so that no deformation of the
flues may occur.
The heated gases pass first through the half flues, according to the arrangement of
the fiues, then play round the outside of the shell of the boiler, and finally escape by
the chimney shaft.
A firegrate may be placed in each of the half flues, and this kind of boiler can be
used both with steam coal and soft coal, with flat & step grates, for internal or
front firing.
The method of construction admits also of the firegrate being placed in one half
flue only; the heated gases then pass through each half-flue in succession. In this
case communicating chambers must be built at the ends of the boiler to lead the
heated gases from one half-flue to the other.
In consequence of this special construction of the flues a very much greater evapor-
ative power is obtained with a relatively small firegrate area, than is the case with
the ordinary boilers as usually constructed with one or two flues, since the circula-
tion of the water between the division walls is more brisk, and a greater efficiency
of the boiler is obtained owing to the increased internal heating surface of the boiler,
which comprises the addition of the height of the division walls (diameter of the flues)
multiplied by the whole length of the boiler.
1

page_text: As already stated it is not essential that the division of the flues should extend
from one end of the boiler to the other. I prefer rather in boilers with internal firing
to make the division walls b¹ b¹ reach up to the furnace bridge d so that the first
section of the flue in which is the furnace, is not divided.
At the point where the heated gases coming from the fire grate after passing over
the furnace bridge d impinge on the division walls b¹ 61, the front joint is protected
from burning by small brickwork projections g (Fig. 3).
Having now particularly described & ascertained the nature of my said Invention,
and in what manner the same is to be performed, I declare that what I claim is. :
1. The construction of a steam boiler with one, two or more flues or fire-tubes, in
which one or all of the above mentioned flues are divided lengthwise into two divisions,
either wholly or in part, by division walls, through which the heated gases pass in
the direction of their length, & in which the division walls are held unalterably at a
fixed distance apart, either parallel, converging or diverging, by means of stay bolts
or other similar arrangement, as is herein described and illustrated.
T
L
CARMAN & Co.,
Agents for Applicant.