Improvements relating to the Lagging of Furnaces and Bollers.
Year: 1892

page_text: Date of Application, 5th Aug., 1892
Complete Specification Left, 29th Apr., 1893-Accepted, 2nd June, 1893
PROVISIONAL SPECIFICATION.
Improvements relating to the Lagging of Furnaces and Bollers.
We JOSEF KIRCHMANN, Builder, of Reichenbachstrasse Munich and KASPAR
SCHWINGHAMMER, Builder of the same address Munich in the Empire of Germany
do hereby declare the nature of this invention to be as follows:--
This invention relates to the lagging or casing which is built around boilers or
furnaces in general for the preservation of the heat and it consists in the improved
construction for this purpose hereinafter described.
The walls composing the lagging are made double that is to say with an air
space between the two comparatively thin wallings and they are strengthened by
cross partitions at intervals, these also serving to divide the said air space into
chambers or flues by means of which it is possible to heat the incoming air which
supplies the furnace and also utilize to the utmost the heat contained in the gases
and smoke passing off.
A metal network or trellis work of suitable strength preferably made of iron rods
bound together at their crossing places is made to the form of the wall to be made
and is plastered on both sides with a thick and close covering of plaster composed
of the materials hereinafter mentioned. The cross partitions suitably located and
the inner and outer wallings are made thus the whole construction consisting of
such plastering on a foundation or interior webbing or framing of metal. Those
parts of the furnace which come actually into contact with fire or flame may-be
built of fire bricks as usual, the plastering for the remainder constructed on the
above principle is chosen according to the temperature it is intended to bear the
outer lying parts being therefore, if desired, plastered with a different mixture to
that used for the inner parts.
For walls exposed to high temperature, fire brick earth, also clay, graphite and
asbestos and if desired magnesia are used with a binding medium consisting of
acetic acid and iron fillings or forge scales, or in place of this medium solution of
borax or of common salt. Waterglass may also be used as a binding medium if the
temperature to which the wall will be exposed is not too high.
Excellent results may be attained with two parts of fire brick earth, one part of
graphite and one part asbestos with acetic acid and iron fillings as binding
medium.
When the wall is not exposed to direct heat from the fire gases the following
mixture may be used: Flint or ordinary clay, quarz-sand, powdered heavy spar or
flour spar or cryolite with a binding material such as waterglass, borax, or salt
solution, or cement or gypsum (the latter only for walls subject to very low
temperature). These can be used alone or mixed and also with or without
admixture of coal ashes and cinders which can be added to any of the mixtures
even those for high temperatures.
The higher the temperature to be withstood the greater the proportions of fire
brick earth, graphite and asbestos used in preparing the plaster.
-
Dated this 5th day of August 1892.
HERBERT & Co.,
Agents to Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Lagging of Furnaces and Boilers.
We JOSEF KIRCHMANN, Builder of Reichenbachstrasse, Munich and KASPAR
SCHWINGHAMMER, Builder of the same address, Munich in the Empire of Germany,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described in and by the following statement :-
This invention relates to the lagging or casing which is built around boilers or
or furnaces in general for the preservation of the heat, and it consists in the
improved construction for this purpose hereinafter described.
The walls composing the lagging are made double, that is to say with an air
space between two comparatively thin wallings and they are strengthened by cross
partitions at intervals, these also serving to divide the said air space into chambers
or flues by means of which it is possible to heat the incoming air which supplies the
furnace and also utilize to the utmost the heat contained in the gases and smoke
passing off.
A metal network or trelliswork of suitable strength preferably made of iron
rods bound together at their crossing places, is made to the form of the wall
to be made and is plastered on both sides with a thick and close covering of
plaster composed of such materials as are hereinafter mentioned. The cross
partitions, suitably located and the inner and outer wallings are made thus, the
whole construction consisting of such plastering on a foundation or interior
webbing or framing of metal. Those parts of the furnace which come actually
into contact with fire or flame may be built of fire bricks as usual, the plastering
for the remainder constructed on the above principle is chosen according to the
temperature it is intended to bear, the outer lying parts being therefore, if
desired, plastered with a different mixture to that used for the inner parts.
For walls exposed to high temperature, firebrick earth, also clay, graphite,
and asbestos and if desired magnesia are used with a binding medium consisting
of acetic acid and iron fillings or forge scales, or in place of this medium,
solution of borax or of common salt. Waterglass may also be used if the
temperature to which the wall will be exposed is not too high.
Excellent results may be attained with two parts of firebrick earth, one part of
graphite, and one part of asbestos with acetic acid and iron fillings as binding
medium.
When the wall is not exposed to direct heat from the fire gases, the following
mixture may be used :-Flint or ordinary clay, quartz sand, powdered heavy
spar or flour spar, or cryolite with a binding material such as waterglass, borax
or salt solution, or cement or gypsum (the latter only for walls subject to very
low temperature). These can be used alone or mixed, and also with or without
admixture of coalashes and cinders which can be added to any of the mixtures,
even those for high temperatures.
The higher the temperature to be withstood the greater the proportions of fire-
brick earth, graphite and asbestos used in preparing the plaster.
For walls which are not exposed to the heating effect of the fire gases,
cinders and cement with possible admixture of firebrick earth will suffice. A
suitable composition for such wallings as are immédiately exposed to either fire
gases or the fire itself is as follows.
4 parts of Portland cement.

page_text: Fig. 1 is the cross section of such a wall a with bar trellis 6 represented in
natural size.
Fig. 2 shows a cross section through a boiler lagging on a smaller scale, showing
also in what way the double wallings are connected at different places and intervals
by cross walls a¹ a' for purposes of stability.
Fig. 3 is a vertical longitudinal section through the middle between a pair of
boilers.
Fig. 4 is a vertical longitudinal section through the boiler axis.
Fig. 5 is a horizontal section through the front wall of the boiler on the line ex
Fig. 4.
Fig. 6 is a vertical cross section on line y-y and Fig. 7 is a horizontal section
on line Fig. 4.
Fig. 8 is a back view and Fig. 9 a front view of the boiler lagging. Fig. 10
shows a lateral elevation, Fig. 11 a horizontal section.
Fig. 12 is a section on the line tt Fig. 4.
Fig. 13 a section on the line u u and
Fig. 14 represents a bar trellis.
The bar trellis is made of quadrangular iron (about 5 to 7 mm. thick) con-
nected at the crossing places with yellow brass wire.
The boilers are, with exception of the front wall surrounded by the double
bar trellis wallings a with horizontal and vertical connecting partitions a¹ a².
The air chambers of each boiler are separated by the middle wall a' so that
they may be used separately for each boiler as channels for heating the supply
of air to the fire.
Fig. 8 shows the air chambers outwardly closed by means of slides c for
regulation of the supply of air.
The air introduced between the double walls and there heated is carried under-
neath the grate through the channels & d, Figs. 3, 4 and 6 with regulating slides
or dampers d' d'.
As shown in Fig. 6 the supply of the air in the interior between both furnaces
is effected in a similar way but as there is only a little space for the channels,
the partition wall is formed of sheet iron e. The downward leading channels f
also pass between two sheet iron walls. These channels conduct heated air under
the grate.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed we declare that what we
claim is.
An improved lagging for furnaces and boilers consisting of iron trellis work
covered with a plaster composed of cement, cinders, coalashes or if desired also
with admixture of firebrick, graphite and asbestos, built to form double walls
of small several thickness, stiffened by cross walls and enclosing air spaces which
may serve for heating the air for supplying the furnace.
Dated this 29th day of April 1893.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicants.