Title of Invention

"METHOD FOR CONVERTING AN INSTALLATION FOR HEAT TREATMENT, A GRATE CARRIAGE AND AN INSTALLATION THEREOF"

Abstract Method for converting an installation for the heat treatment of finegrained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, which travelling grate is formed by a plurality of grate carriages (11) , each grate carriage (11) having a grate (14), a grate carriage body (12) arranged below it with in each case two opposite, substantially vertical longitudinal and transverse walls, and side walls (16) which extend upwards from the longitudinal sides of the grate carriage bodies (12), with the longitudinal and side walls arranged substantially flush above one another, characterized in that the grate carriage bodies (12) of each grate carriage are replaced by grate carriage bodies (12) whereof longitudinal walls are inclined outwards in the upward direction at an angle, and in which outwardly projecting gastight bearing elements (15) adjoin the longitudinal sides of the grates (14).
Full Text The present invention relates to method for converting an installation for heat treatment, a grate carriage and an installation thereof.
The invention relates to a method for converting an apparatus for the heat treatment of fine-grained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a grate for receiving the substances that are to be treated, in order to increase the capacity.
In apparatuses of this type, the maximum quantity of material to be treated which can be placed onto the grate is limited primarily by the height of the side walls, the grate surface area and the capacity to suck treatment gas through the bed of granular material.
In principle, it is desirable to increase the capacity of heat treatment installations of this type. However, to procure a new plant with a higher capacity is disadvantageous on account of the high investment costs involved.
Grate carriages for sintering installations and pellet-firing installations usually comprise in particular the following parts:
the single-part or multipart grate carriage body, which is equipped, inter alia, with running rollers, the grate, which is arranged at the top side of the grate carriage body and is supported by the latter, what are referred to as the side walls, which are installed at the two longitudinal sides of the grate carriage and thereby delimit the grate, i.e. the width of the reaction surface.
Beneath the grate, the grate carriage body with the reinforcing ribs and longitudinal and transverse walls which adjoin the grate approximately at right angles forms spacers (which can already be regarded as part of the suction boxes), through which the off-gas or process air is passed to the suction lines when the
sintering or pellet installation is operating. To
protect the transverse walls and reinforcing ribs from
wear and excessive thermal loads, the upper side
thereof is protected by what are known as exchangeable
insulating pieces. Sealing elements, which seal off the
grate carriage with respect to the pipe system
connected to it in this region, are arranged at the
underside of the longitudinal walls of the grate
carriage. The grate is formed by individual grate bars
which are mounted in the region of the top side of the
reinforcing ribs and transverse walls running
transversely with respect to the grate carriage
longitudinal direction or in the insulation pieces
which are usually arranged there. The grate carriages
form the majority of the travelling grate of a
travelling grate sintering machine or a travelling
grate pellet-firing machine.
It is attempted by converting existing installations to
achieve increases in capacity at lower investment cost.
For example, it is known from AT 395353 B to increase
the capacity of grate carriages of a sintering
installation by fitting gas-impermeable bearing
surfaces between the grate and the side walls.
However, it has emerged that this measure cannot
increase the capacity of a grate carriage to the
desired extent.
Therefore, the object of the present invention is to
increase the capacity of an apparatus for the heat
treatment of fine-grained substances to a greater
extent than would be possible by means of gasimpermeable
bearing surfaces alone yet without
requiring completely new investment.
It has been possible to achieve this object by the
conversion method according to the invention which
comprises the
removal of at least two opposite side walls and of at
least the adjoining upper parts of at least two
opposite suction box walls,
fitting of upper parts of the suction box walls, which
are inclined outwards in the upward direction, to the
remaining lower parts of the suction box walls,
fitting of gas-impermeable bearing elements, which
extend further outwards in the lateral direction, to
the upper parts, which are inclined outwards in the
upward direction, of the suction box walls,
fitting of side walls to the side edges of the gasimpermeable
bearing elements, and
fitting of a grate which covers the entire clear upper
cross-sectional area of the suction box.
Although the present invention likewise makes use of
the step of fitting gas-impermeable bearing elements
and the associated increase in capacity, a further
crucial aspect is the conversion of the suction box, in
particular the replacement of parts of the vertical
suction box walls with suction box walls which are
inclined obliquely outwards in the upward direction.
The embodiment of the invention described above is
aimed at converting an apparatus in which the suction
box directly adjoins the grate beneath it. Apparatuses
of this type do not usually have a travelling grate,
but rather have a stationary grate, for example
sintering pans.
According to an advantageous embodiment, the method
according to the invention is carried out in such a
manner that the upper parts, which are inclined
outwards in the upward direction, of the suction box
walls include an angle of 30 - 60, preferably of 45°,
with the vertical.
According to a further advantageous embodiment,
opposite suction box walls are completely removed and
are replaced by suction box walls which in each case
have a vertical lower part and an upper part which is
inclined outwards in the upward direction.
The height of the removed upper part of the suction box
walls preferably amounts to 1/30 to 1/5 of the width of
the grate that was originally present.
In combination with the upper part of the suction box
walls being inclined preferably at an angle of 45° with
respect to the vertical, this ultimately widens the
area through which gas can pass, likewise to an extent
of 1/30 to 1/5 of the width of the grate that was
originally present.
The width of the gas-impermeable bearing elements
preferably likewise amounts to 1/30 to 1/5 of the width
of the grate that was originally present.
Overall, the combination of the two measures widens the
grate by 10 to 40%. These details apply to grate
carriages with a width of, for example, 4 m, which have
been widened to 5 m by the method according to the
invention. In some cases, the widening that can be
achieved may be even greater.
A further embodiment of the method according to the
invention is aimed at the conversion of an installation
with a travelling grate. Installations of this type,
which were described in the introduction, form the
majority of the capacity of sintering or pellet-firing
installations.
Therefore, this further embodiment of the method
according to the invention relates to a method for
converting an installation for the heat treatment of
fine-grained substances, in particular an apparatus for
drying, firing and/or sintering fine-grained raw
materials to be used in the iron industry, having a
travelling grate, which travelling grate is formed by a
plurality of grate carriages, each grate carriage
having a grate, a grate carriage body arranged below it
with in each case two opposite, substantially vertical
longitudinal and transverse walls, and side walls which
extend upwards from the longitudinal sides of the grate
carriage bodies, with the longitudinal and side walls
arranged substantially flush above one another.
In this further embodiment of the method according to
the invention, the object which is set in accordance
with the invention is achieved by the fact that the
grate carriage bodies of each grate carriage are
replaced by grate carriage bodies whereof longitudinal
walls are inclined outwards in the upward direction at
an angle, and in which outwardly projecting gastight
bearing elements adjoin the longitudinal sides of the
grates.
The terms "longitudinal" and "transverse" relate to the
movement of the grate carriage when the installation is
operating. "Longitudinal walls" or "longitudinal sides"
are arranged parallel to the direction of advance of
the grate carriage, while "transverse walls" are
arranged at a right angle to the direction of advance
of the grate carriage.
The design of the novel grate carriage according to the
invention differs from the grate carriage which has
previously been designed as standard in particular by
virtue of the following features:
the longitudinal walls of the grate carriage body are
inclined obliquely outwards in the upward direction at
an angle of preferably approx. 45° with respect to the
vertical.
The width of the grate is delimited by the uppermost
part of the longitudinal walls, which are inclined
obliquely outwards in the upward direction, of the
grate carriage body.
Outwardly projecting, gastight surfaces which each have
a width of up to 350 mm adjoin the two longitudinal
sides of the grate.
What are known as the side walls of the grate carriage,
which delimit the width of the reaction area, adjoin
the outer longitudinal sides of the gastight surfaces.
The position of the running rollers and of the
longitudinal seals can remain unchanged at the same
distance from the side walls (= grate carriage width)
compared to conventional grate carriages.
Therefore, the invention also relates to grate
carriages having a grate carriage body, which is formed
by in each case two opposite longitudinal and
transverse walls, a grate arranged at the top side of
the grate carriage body and having two opposite side
walls which extend upwards from the longitudinal sides
of the grate carriage bodies.
The grate carriages according to the invention achieve
the object which is set in accordance with the
invention by virtue of the fact that the longitudinal
walls of the grate carriage body are inclined outwards
at an angle in the upward direction, and that outwardly
projecting, gastight bearing elements adjoin the
longitudinal sides of the grate.
The invention also relates to an installation for the
heat treatment of fine-grained substances, in
particular an apparatus for drying, firing and/or
sintering fine-grained raw materials to be used in the
iron industry, having a travelling grate, in which the
travelling grate is formed by a plurality of grate
carriages according to the invention.
The novel grate carriages according to the invention
have a number of advantages for sintering and pelletfiring
installations:
the width of a building required for the installation
of a sintering machine or pellet-firing machine can be
significantly reduced than when using a grate carriage
of the same grate carriage width, allowing considerable
savings to be made on the investment costs.
The capacity of an existing sintering or pellet
installation can be increased by up to approx. 40% by
the installation of the novel grate carriages according
to the invention, depending on the original grate
carriage width, without the building in which the
sintering machine or the pellet-firing machine is
installed having to be altered, without the adjoining
suction or pressure system, the position of the running
rails and the design of the supporting structure having
to be altered, and with the capacity of the suction and
pressure system only having to be increased in
proportion to the increased grate surface area (without
the gastight surface area which is additionally formed
by the gastight plates).
To convert sintering installations in order to increase
the capacity by installing the novel grate carriages,
these installations only have to be shut down for a
short time (approximately 2 weeks).
The specific off-gas quantity (m3 (s.t.p.)/t of sintered
product) in the sintering installation or the specific
process quantity (m3(s.t.p)/t of pellets) in the case
of the pellet-firing installation is significantly
reduced.
In the text which follows, the invention is explained
in more detail by means of the diagrammatic
illustrations presented in Fig. 1 to Fig. 3 of the
drawings.
In the drawing, Fig. 1 shows a vertical section through
an apparatus prior to conversion, without any of the
parts which are not pertinent to the invention, such as
for example the sealing of the blower box, etc., being
illustrated.
The apparatus of the prior art illustrated in Fig. 1
has a suction box 2, which is formed by suction box
walls 3 that extend downwards to the sides of the grate
1 and to which a suction fan (not shown) is connected.
The suction fan sucks hot treatment gas through the bed
4 of fine-grained substances and the grate 1 from the
top downwards.
Side walls 6 which extend upwards and, as illustrated
in the drawing, vertically, or may also be inclined
outwards, adjoin the grate 1 at the two side edges 5.
For the conversion method according to the invention,
first of all the side walls 6 and usually also the
grate 1 are removed. Then, an upper part of the suction
box walls 3 is removed and the suction box walls 3
(Fig. 1) are shortened to form suction box walls 3a
(Fig. 2).
Then, parts 3b which are inclined outwards in the
upward direction are secured to the lower parts of the
suction box walls 3a, for example by welding. Then,
gas-impermeable bearing elements 8, which are located
approximately at the height of the grate 1, are secured
to the side edges 7 of the parts 3b which are inclined
outwards in the upward direction. The gas-impermeable
bearing elements 8 do not necessarily have to be
designed as plates, but rather may also, for example,
be triangular in cross section.
The side walls 6 which were initially removed are then
refitted to the side edges 9 of the bearing elements 8.
Finally, a grate 10 is put in place, which grate has
either been produced by increasing the size of the
grate 1 or may have been purchased new.
The conversion method according to the invention has
increased the original width A of the grate 1 by in
each case double the lengths, projected into the
horizontal, of the parts 3b which are inclined outwards
in the upward direction (width B) and by double the
width C of the gas-impermeable bearing elements 8.
The embodiment illustrated in Fig. 3 shows a grate
carriage 11 according to the invention in the form of a
cross section through a sintering installation with
travelling grate. The grate carriage 11 has a grate
carriage body 12 which is equipped with running wheels
13. Above this is a grate 14 with gas-impermeable
bearing elements 15 fitted to its longitudinal sides.
Side walls 16 are arranged to the side of the gasimpermeable
bearing elements 15. Beneath the grate
carriage body 12 is a fixed suction box 17. The grate
carriage body 12 illustrated in the figure has
longitudinal walls which are inclined outwards in the
upward direction at an angle of 45° with respect to the
vertical. This has increased the original suction
surface width D to the new suction surface width E. The
gas-impermeable bearing elements 15 have increased the
overall grate carriage width further, specifically to
the new grate carriage width F.








We claim:
1. Method for converting an installation for the heat treatment of finegrained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, which travelling grate is formed by a plurality of grate carriages (11) , each grate carriage (11) having a grate (14), a grate carriage body (12) arranged below it with in each case two opposite, substantially vertical longitudinal and transverse walls, and side walls (16) which extend upwards from the longitudinal sides of the grate carriage bodies (12), with the longitudinal and side walls arranged substantially flush above one another, characterized in that the grate carriage bodies (12) of each grate carriage are replaced by grate carriage bodies (12) whereof longitudinal walls are inclined outwards in the upward direction at an angle, and in which outwardly projecting gastight bearing elements (15) adjoin the longitudinal sides of the grates (14).
2. Grate carriage (11) having a grate carriage body (12), which is formed by in each case two opposite longitudinal and transverse walls, a grate (14) arranged at the top side of the grate carriage body (12) and having two opposite side walls (16) which extend upwards from the longitudinal sides of the grate carriage bodies, characterized in that the longitudinal walls of the grate carriage body (12) are inclined outwards at an angle in the upward direction, and in that outwardly projecting, gastight bearing elements (15) adjoin the longitudinal sides of the grate (14).
3. Grate carriage as claimed in claim 2, wherein the longitudinal walls of the grate carriage body (12) are inclined outwards in the upward direction at an angle of substantially 45° with respect to the vertical.
4. Grate carriage as claimed in claim 2 or 3, wherein the outwardly projecting, gastight bearing elements (15) are up to 350 mm wide.

5. Installation for the heat treatment of fine-grained substances, in particular an apparatus for drying, firing and/or sintering fine-grained raw materials to be used in the iron industry, having a travelling grate, characterized in that the travelling grate is formed by a plurality of grate carriages (11) according to one of claims 2 to 4.

Documents:

5424-delnp-2006-Abstract-(29-05-2009).pdf

5424-delnp-2006-abstract.pdf

5424-delnp-2006-Claims-(29-05-2009).pdf

5424-delnp-2006-claims.pdf

5424-DELNP-2006-Correspondence-Others-(02-12-2009).pdf

5424-delnp-2006-Correspondence-Others-(29-05-2009).pdf

5424-delnp-2006-correspondence-others.pdf

5424-delnp-2006-Description (Complete)-(29-05-2009).pdf

5424-delnp-2006-description (complete).pdf

5424-delnp-2006-Drawings-(29-05-2009).pdf

5424-delnp-2006-drawings.pdf

5424-delnp-2006-Form-1-(29-05-2009).pdf

5424-delnp-2006-form-1.pdf

5424-delnp-2006-form-18.pdf

5424-delnp-2006-Form-2-(29-05-2009).pdf

5424-delnp-2006-form-2.pdf

5424-delnp-2006-form-3.pdf

5424-delnp-2006-form-5.pdf

5424-delnp-2006-GPA-(29-05-2009).pdf

5424-delnp-2006-gpa.pdf

5424-delnp-2006-pct-210.pdf

5424-delnp-2006-pct-304.pdf

5424-delnp-2006-pct-308.pdf


Patent Number 241733
Indian Patent Application Number 5424/DELNP/2006
PG Journal Number 31/2010
Publication Date 30-Jul-2010
Grant Date 22-Jul-2010
Date of Filing 19-Sep-2006
Name of Patentee VOEST-ALPINE INDUSTRIEANLAGENBAU GMBH & CO.
Applicant Address TURMSTRASSE 44, A-4031 LINZ, AUSTRIA.
Inventors:
# Inventor's Name Inventor's Address
1 KARL LAABER ASANGSTRASSE 17, 4407 DIETACH, AUSTRIA.
2 OSKAR PAMMER ESCHENWEG 18, 4040 LINZ, AUSTRIA.
PCT International Classification Number F27B 21/02
PCT International Application Number PCT/EP2005/002428
PCT International Filing date 2005-03-08
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 GM 205/04 2004-03-17 Austria