IMPROVEMENTS IN FURNACE GRATES
Year: 1873

page_text: LETTERS PATENT to Charles Knoblauch, of Münich, in the Kingdom
of Bavaria, Civil Engineer, for the Invention of "IMPROVEMENTS IN
FURNACE GRATES."
Sealed the 9th January 1874, and dated the 20th August 1873.
•
COMPLETE SPECIFICATION filed by the said Charles Knoblauch at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 20th August 1873, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
KNOBLAUCH, of Munich, in the Kingdom of Bavaria, Germany, Civil
Engineer, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN FURNACE GRATES," and have petitioned Her most Excellent Majesty
Queen Victoria to grant unto me, my executors, administrators, and
assigns, Her Royal Letters Patent for the same, and have made solemn
Declaration that I am the first and true Inventor thereof.

page_text: NOW KNOW YE, that I, the said Charles Knoblauch, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, reference being had to the accompanying Sheet
of Drawings, and to the figures and letters marked thereon, that is
to say :-
Fire-bars exposed to considerable heat are necessarily made of
considerable strength to provide against their bending and to allow for
portions of their upper surface being burnt away. They are therefore
usually made broad on their upper surface with considerable spaces
left between them to allow for their horizontal flexure, and to give
room for the removal of burnt or bent bars and for replacing them by
new bars. Great disadvantages result from this, some of which are as
follows: As the bars present largo surface to the fire they cannot be
sufficiently cooled by the passing air, and they consequently become
rapidly burnt, the fuel lying on the bars does not receive its proper
supply of air for combustion, clinkers are therefore formed, which
interfere with the combustion and necessitate a great reduction of the
heat during their removal; owing to the wide spacing of the bars small
coal cannot be used as it falls through to the ash-pit, and even if it
be agglomerated at considerable expense into blocks, these blocks
frequently in the act of combustion become disintegrated and the
material of which they are composed falls through the grate uncon-
sumed.
My Invention relates to a construction and arrangement of fire-grate
suitable for the furnaces of steam or other boilers, and for furnaces
of other kinds, devised so as to obviate the disadvantages mentioned
above and to secure complete combustion of the fuel, to prevent small
coal or dust from falling through the grate, and to provide great
strength of grate combined with lightness of bars..
. In the accompanying Sheet of Drawings Fig. I. shews a side view of
one of the side frames of the improved fire-grate; Fig. II. represents
a longitudinal section, and Fig. III. a plan of the fire-grate; Fig. IV.
shews a side view and transverse sections of the bearing bars, and
Fig. V is a transverse section through the fire-grate.
At each side is fixed a strong side frame a which may be made with
flanges for laying on brickwork, as shown in Fig. V., to these side

page_text: frames aro bolted by angle brackets n bearing bars b, shaped like
inverted troughs with holes m through them for free passage of air.
The fire-bars c³, c², c³, are made thin and closely spaced, and are
of open triangular shape to give great vertical strength. They rest at
each end on the bearing bars 6 and also in the middle on stretching
bolts d which unite the two side frames a. The holes and the bars
through which the bolts & pass are slotted so as to allow for expansion
or contraction of the bars.
It will bo seen that the side frames a are curved vertically, and tho
fire-bars are laid in this curved form, and that each length of bar rests at
the one end on a bearing bar and at the other end on a curved seating
formed on the end of the next length of bar. Thus the bars are free
to move à little longitudinally when expanded or contracted without
being strained or bent vertically.
At the ends the bars are widened out as usual so as to abut on cach
other laterally; they are also provided with studs about the middle of
their length, each of which abuts on the side of the adjacent bar. The
bars being thus confined at their ends and middle between the two side
frames are kept from bending horizontally. The open form of the
fire-bar while it gives great vertical strength renders the bar light, so
that it can easily be moved and replaced by hand, and allows free play
to the entering air over all its surface, so as to prevent it from being
overheated, and farther the weight of the fire instead of being thrown
as usual on bars supported at the ends only, is borne by bars supported
at three points, and transferred by them to the strong side frames
through the bearing bars and stretching bolts. By this arrangement
the old fire-grate is made as it were to be in one piece expanding and
contracting together, and the bars being releived of much of the strain
to which fire-bars are usually subjected, can be made thin and closely
spaced, so as to afford uniform access of air to the whole of the fuel, and
to permit fuel in small particles to be burnt upon them.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim,-
First. The use of side frames tied together by stretching bolts for
supporting the bearing and fire-bars of furnace-grates, substantially as

page_text: Second. The use for furnace grates of bearing bars of inverted trough
form with holes through their sides for free passage of air, substantially
as herein described.
Third. The use of thin fire-bars of open triangular form supported at
the ends and in the middle, substantially as herein described.
Fourth. The. combination of side frames, bearing bars, and fire-bars,
such as are referred to above so as to form a furnace grate, substantially
in the manner and for the purposes herein-before set forth.
In witness whereof, I, the said Charles Knoblauch, have hereunto
set my hand and seal, this Fourth day of August, in the year of 1
our Lord One thousand eight hundred and seventy-three.