Note: Descriptions are shown in the official language in which they were submitted.
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Burner Holding Device Comprising a Cooling System for a
Burner Arrangement in an Entrained Flow Gasifier
[0001] The invention relates to a burner holding device
comprising a cooling system for burners, in particular for
burners, which are arranged in operative connection with an
entrained flow gasification reactor.
STATE OF THE ART
[0002] Different devices for cooling reactor burners are
known from the state of the art.
[0003] In the case of the currently known constructions in
the field of the burner holding devices of burner systems
comprising pilot, main and ignition burners, which are in
operative connection with reactors for entrained flow
gasification, the designs for the cooling system of the
burners are for the most part embodied as pipe coil system
and comprise water supplies and discharges. The designs of
the cooling device still raise constructional questions, so
that such a cooling at the interface burner-reactor is
ensured in response to an optimal system design and clever
arrangement of the burners above the actual reactor, thus
avoiding the overheating of components, which endangers the
safety of the system. A safety risk because of a lack of
cooling is created when an overheating leads to leakiness of
parts of the arrangement and gases can thus escape from the
system. Known systems thus raise questions relating to the
safety and the maintenance; in most cases, an improved safety
requires a high capital expenditure.
[0004] A device for burner fastening comprising an
integrated cooling system is described in DE 269 065, for
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example. The chosen spring elements for the cooling pipe
fastening, the arrangement of cooling pipes and the
possibility of only integrating one burner leads to a danger
of slagging in a disadvantageous manner at the outer edge of
the reactor and to an output potential, which is too low for
large reactors.
[0005] DE 44 16 037 C1 describes a device for closing an
inspection opening and for fastening the burner for
pressurized gasification reactors, which is characterized by
a cooling disk for a specific cooling water supply and
discharge as well as a special pipe suspension for the pipe
system for the heat discharge. This solution also does not
fulfill the demands on safety, ease of maintenance and cost
expenditure, which are to be made on a system comprising a
plurality of burners and large output for such reactors.
[0006] There is thus the demand for improving the system
safety with reference to uncontrolled overheating of the
reactor closure.
DISCLOSURE
[0007] Based on this state of the art, the present
invention is based on the object of creating an improved
burner holding device comprising a cooling system for a
burner arrangement in an entrained flow gasifier. This object
is solved by means of a device comprising the features of
claim 1. Preferred embodiments are described in the dependent
claims.
[0008] An embodiment of the invention relates to a burner
holding device, which is arranged on an entrained flow
gasification reactor. The burner holding device includes at
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least two burners, which are guided into the entrained flow
gasification reactor. The burner holding device is closed
towards the top by means of a flange, through which the
burners and required supply and discharge lines extend. A
cooling device is arranged in the burner holding device.
Advantageously, it comprises at least two cooling circuits,
which are independent from one another. The failure of the
one cooling circuit can thus be compensated by the other
cooling circuit. Each cooling circuit is furthermore assigned
to only one burner, which, however, can advantageously be
divided into sections, so that a further section is available
for cooling the surface, which is located at the front side
of the entrained flow gasification reactor. An even cooling
can thus be ensured on the entire interface between reactor
and burner. The cooling pipe coils, which form the cooling
circuits, are arranged in a stable manner without further
mounting by means of this construction in an advantageous
manner. The layer design of the interior of the burner
holding device, which initially consists from bottom to top
of heat conducting and then of insulating material, is
furthermore advantageous, so that the desired heat discharge
takes place only at the desired areas, while overhead an
unnecessary temperature loss of the system cannot take place.
[0009] Advantageously, the cooling device can be provided
from cooling coils, which can be wound cleverly and without
cooling gaps.
[00010] A further exemplary embodiment relates to the fact
that at least 20% of the overall height of a burner are
surrounded by a corresponding section of the cooling coil
without cooling gaps, so that at least the hot zone of the
burner, which encompasses temperatures from 1600 C to 1800 C,
is cooled reliably.
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[00011] Even further embodiments disclose the
advantageously independent charging of the independent
cooling circuits, with coolant simultaneously.
[00012] Embodiments finally refer to the fact that said
layer of insulating material is a sealing compound, which is
fire resistant up to at least 800 C, comprising a thickness
in the range of 2.0 kg/l, preferably below 1.5 kg/l. This can
be lightweight refractory concrete.
[00013] Even further embodiments specify that the layer
consisting of up to at least 800 C fire resistant loose
material is a fire clay granulate material or another
lightweight refractory brick granulate material.
[00014] The heat conducting layer can furthermore be a
refractory concrete, in particular a dense heavyweight
refractory concrete, while the insulating layer
advantageously is a non-dense refractory concrete.
[00015] These and further advantages become obvious from
the following description.
BRIEF DESCRIPTION OF THE FIGURES
[00016] The reference to the figures in the description
serves to support the description. Objects or parts of
objects, which are substantially identical or similar, can be
provided with the same reference numerals. The figures are
only schematic illustrations of embodiments of the invention.
[00017] Figure 1: shows a longitudinal section through the
burner holding device according to the invention comprising
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the arrangement of the cooling system comprising burner
fastening, main burners, start burner, individual cooling
coils and cooling coil arrangement as well as layer
materials.
[00018] Figure 2: shows a top view of the reactor
comprising a partial section.
DESCRIPTION
[00019] The device of the present invention serves for the
improved cooling and thus for the improved system safety of a
device, which is suitable to generate synthesis gas and which
comprises one burner or a plurality of burners, which are
arranged in operative connection with an entrained flow
gasifier. Principally , the burner holding device according
to the invention comprising a cooling system for burners
serves to cool the space located around the burner or the
burners and which extends from a side of the burner holding
device facing the reactor, identified hereinbelow as "front
surface of the reactor", to a device for holding the burner
or the burners, which will advantageously be a flange. A
thermal overheating of the claimed components can be avoided
by means of the provided cooling. In particular, seals, such
as the flange seal, and individual flanges, which are
arranged on the pipes holding the burners, are protected
against overheating by reducing the temperature and it is
avoided that the flanges, seals and other components are
damaged by such an overheating, which could lead to the
escape of gases, which contribute to the reaction, which is
carried out. As is known to the person skilled in the art,
such a gas escape holds an enormous potential of danger. The
reduction of the temperature further serves to protect the
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material of involved components, thus reducing maintenance
costs.
[00020] To provide an improved cooling system for such
burners, which are coupled to an entrained flow gasifier and
which are thus arranged at the front sides thereof and which
are held there accordingly by a holding device, provision is
thus made according to the invention for a plurality of
cooling devices, which are independent from one another,
which cool this front side as well as the hottest sections of
the burners. The holding device for the burners, within which
the cooling device is arranged, is identified herein as
"burner holding device". A plurality of pipe coil cooling
systems operating independent from one another is provided as
cooling devices. Systems for the production of synthesis gas,
which encompass a burner as start burner, which is arranged
in the center of the holding device and which encompass a
plurality of burners as so-called main burners, so that they
are arranged equally spaced apart from the central burner, if
applicable, can thus be equipped with a so-called "inner
cooling circuit" for cooling the central burner and with an
outer cooling circuit for cooling the burners located outside
of the center. Part of the burner holding device can be
provided therewith by means of pipe coils for cooling outer
and inner cooling circuits, which are independent from one
another and which are identified hereinbelow as "bottom
part".
[00021] It is important thereby that different burners,
such as start and main burners, which render different
functions, such as different output, for instance, are cooled
by means of cooling circuits, which are independent from one
another, so as not to cause an overheating of the entire
burner holding device in the event of a cooling circuit
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breakdown, if applicable. However, a cooling circuit can
simultaneously be assigned to a burner and to a part of the
front surface for cooling; however, it then encompasses
virtually different sections, one horizontal section and one
vertical section, which forms a collar around the burner in a
manner of speaking.
[00022] On the one hand, a cooling is thus provided in the
plane, which provides the interface between reactor and
burner holding device (the front surface). On the other hand,
the burners, such as start burner and main burner, for
example, are additionally cooled in their lower area.
Conventional burners are substantially embodied as pipes.
They can already be cooled sufficiently by means of an at
least partial cooling, which takes place around its hottest
area, thus around the pipe end (referred to hereinbelow as
lower end) of the burner facing the reactor by means of
cooling pipe coils. It can thereby be sufficient to cool only
the lower third of the burner. Advantageously, at least the
lower fifth of the burner is cooled, thus approximately 20%
of the burner height, based on its overall height within the
burner holding device.
[00023] In the case of a different burner geometry, it
makes sense for the burner to be wrapped with cooling coils
to the extent that the zone in which temperatures of up to
1800 C prevail, are cooled indirectly. The winding of the
cooling coils of the cooling circuits of the different
burners operating separately from one another is thereby
guided such that no cooling gaps are created. Such a winding
is known to the person skilled in the art.
[00024] The pipe coil length for the burner cooling of the
individual burners, thus of the section of the pipe coil
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located as winding around the lower burner part, can be more
than 20% of the overall length of the entire individual
cooling system. The pipe coil cooling system, which is
arranged around a main burner, can be sectioned into two or
more individual systems. The wound pipe coil sections, which
quasi form a "collar" on the lower part of the burner around
the guide pipes thereof, are thus cooled in the same way as
the collars, which are located around the guide pipes of the
start burner, thus simultaneously to the pipe coil sections,
which are located on the front side of the reactor. Thus,
advantageously a closed cooling surface is provided on the
front surface of the reactor and along the lower section of
all of the burners, wherein the height of the collars can be
chosen independent from one another. It is further
advantageous that the cooling of the lower areas of the
burners takes place simultaneously through the cooling
circuits arranged independent from one another, so that the
breakdown of a cooling circuit does not lead to an
overheating of the entire burner holding device, because the
further provided cooling circuits can compensate for the
error.
[00025] To protect the side of the overall system facing
the interior of the reactor and the bottom parts of the
individual burners from thermal overheating, the cooling coil
system of the individual cooling systems is designed such
that the outer cooling system takes over the cooling of the
upper side of the reactor as well as the cooling of the lower
areas of the main burners. Advantageously, the cooling device
according to the invention comprising the burner holding
device thus presents a cooling, which goes beyond the cooling
described in the state of the art, which furthermore provides
for an improved safety by means of separate cooling circuits.
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[00026] In the exemplary embodiments of the invention, the
individual pipe coil cooling systems cool the surface of the
burner holding device facing the reactor, thus also the lower
areas of the main burners and of the start burner. The
simultaneous cooling of individual burners and of said
surface leads to particular advantages relating to
construction of the type that a special mounting of the pipe
coils is superfluous or not necessary. In response to the use
of two cooling circuits, the pipe lengths for the respective
section abutting on the plane and for the section forming the
collar can be the same, so that 50% of the overall cooling is
still provided in response to the breakdown of a cooling
system.
[00027] In the case of a centrally arranged start burner,
the cooling can take place such, that for instance the start
burner comprising the inner cooling circuit, including the
supply and discharge pipes for the cooling water, forms a
constructive unit.
[00028] In the case of the burner holding device according
to the invention, the outer cooling system for the main
burner or the main burners can be fastened to a casing, which
is fastened to a flange, the so-called main flange, which is
located at the upper ends of the burners. The fastening can
take place on a collar or projection. This casing also serves
to accommodate further components, which hold the burners,
which also take over protective functions with reference to
the temperature control.
[00029] According to the invention, the main flange of the
burner holding device, which will carry the essential portion
of the pressure created in the system, and the further
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components are protected against overheating by means of the
following arrangement.
[00030] Layers of heat-conducting and heat-insulating
materials are provided within said casing below the flange,
which form protection in many ways. The lower area of the
burners, which are wrapped with the cooling coils such that
so-called collars are formed, are cast with a mass, which has
an application temperature of at least 1500 C, which is thus
fire resistant up to this temperature and which shows a very
good to good heat conductivity. The dense casting compounds
comprising the main component silicon carbide having heat
conductivities of from 5 to 15 W/m K at temperatures of
1000 C as well as dense fire resistant concrete comprising
the main components aluminum oxide and/or chromium oxide
and/or silicon dioxide having heat conductivities of from 3.0
to 4.0 W/m K at temperature of 1000 C are considered to be
suitable masses for this lowermost layer. These fire
resistant casting compounds can exhibit densities of from 2.4
to 3.6 kg/l. Preferred casting compounds can exhibit
densities in the range of from 2.5 to 2.7 kg/l; on principle,
however, such a suitable fire resistant mass or the
refractory concrete can have a density of from 2.0 to 4.0
kg/1.
[00031] To protect the cooling coils of the burner holding
device on the burner chamber side against the corrosive and
chemical attack of the gas atmosphere and the slag, they can
furthermore be provided with the studding and coating, which
is common from the state of the art of power plant and
gasification technology, comprising suitable SiC-containing
ramming masses of high heat conductivity.
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[00032] Underneath the main flange, the space between the
burners is filled with an insulating, less dense casting
compound, which exhibits a density in the range of from 1.0
to 2.0 kg/l. This includes the heat insulation and
lightweight refractory concrete, which holds a high heat
insulation comprising a heat conductivity of approximately
0.1 to 0.8 W/m K.
[00033] Between the layer consisting of highly insulating
casting material at the main flange and highly heat-
conducting material on the lower end of the burners, the
space is filled with a loose, heat-insulating loose material,
which can be a fire resistant insulation granulate material,
for instance of fire clay or another lightweight refractory
brick. The preferred density lies in the range of around 1
kg/l, the fire resistance is to lie at at least 800 C. A
suitable grain size lies at 8 to 12 mm, a grain size of a
diameter of approximately 10 mm is preferred.
[00034] The entrained flow gasification reactor itself also
encompasses a cooling jacket, which extends upwards to the
burner holding device such that it surrounds the front
surfaces like a collar. This collar virtually surrounds the
cooling system provided by the burner holding device. In the
device according to the invention, the height of the outer
ring of the burner holding device wound by the cooling pipes
corresponds to the height of the wound collar of the cooling
jacket of the reactor located opposite thereto, so that an
annular gap is created between the two cooling systems. This
gap can be adjusted with a gap width of 5 to 50 mm between
the cooling elements, the cooling collar of the reactor and
the wound outer ring of the burner holding device.
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[00035] Advantageously, the adjusted annular gap is
continuously flushed with inert gas, so that none or only
negligible amounts of reaction gases, which eventually
permeate into the annular gap, collect and corrosive forces
can develop. The inert gas flushing of the annular gap thus
also serves to protect the burner holding device. Towards the
outside, the annular gap is filled with packages consisting
of fire resistant flexible sealing cord, which consist of
suitable ceramic fibers from the main component aluminum
oxide and silicon dioxide, which ensure a sufficient
permeability for the dispersion of the inert flushing gas for
flushing the annular space and for securing the thermally-
related relative motions of the cooling jacket as well as of
the burner holding device as a whole.
[00036] According to the invention, the burner holding
device is filled with loose heat-insulating loose material,
as explained, and is defined against the main flange with a
rolled jacket, the described casing, wherein the rolled
jacket is held on the collar of the main flange by means of
groove pins or other fastening devices. In so doing, the
jacket can be disassembled downwards after removal of the
groove pins in case of repair. The heat-insulating loose
material thus falls out of the burner holding device and a
replacement of the cooling element is possible without any
problems after separating the cooling water pipes.
[00037] In the case of a centrally arranged start burner 4
and a locally arranged main burner 5, Figure 1 shows an outer
cooling circuit 1 and an inner cooling circuit 2 comprising
the pipe coil section, the start burner cooling section 3,
arranged at the start burner 4. The pipe coil section 6 takes
over the cooling of the lower area of the main burners 5. The
entire burner holding device 7, the components of which are
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substantially replaceable and which is arranged above the
reactor system 8, also serves for the supply and discharge of
the required cooling water quantities via the pressure joints
and pipes 9, 10. As shown in Fig. 1, the cooling water for
the cooling of the individual systems is supplied via the
pressure joints 9, 10 and via further non-illustrated joints,
which are welded to the main flange 11.
[00038] The cooling for the centrally arranged start burner
4 takes place via the cooling coil system, which takes over
the cooling of the inner area of the overall system of the
burner holding device 7 as well as of the lower part of the
start burner 4. The fastening of the pipe coil system, which
provides the outer cooling circuit 1, takes place at a
separate casing 12, which is fixedly connected to the main
flange 11 of the overall system. The main flange 11 is
protected against excessive thermal stress by means of a
system assembled from a plurality of components consisting of
different heat-conducting materials, which comprises a loose
heat-insulating material 17 for filling the cavity, a heat-
conducting refractory concrete layer 18 and an insulating
lightweight refractory concrete layer 19.
[00039] A section of the cooling coils extends on an outer
edge of the burner holding device, while forming an outer
ring 13, from the front face. of the entrained flow
gasification reactor upwards and at least along a part of the
casing 12, wherein a height of the cooling coil pipes
extending upwards corresponds to a height of a collar 14 of a
cooling jacket of the entrained flow gasification reactor 8,
so that an annular gap 15, which encompasses a gap width of
from 5 to 50 mm, is provided between the collar 14 and the
cooling coil pipes extending upwardly.
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[00040] At the lower end of the burner holding device 7,
the annular gap 15 is provided with a sealing cord package
20, which prevents the permeation of slag into the annular
gap 15.
[00041] Fig. 2 shows the burner holding device 7 in the top
view; three main burners 5 are surrounded by an outer cooling
circuit 1, which is fed via the cooling water supply joints 9
and 10. The start burner 4 is surrounded by an inner cooling
circuit 2, also fed by cooling water supply joints 9 and 10.
The section of the inner cooling circuit 2 is the start
burner cooling part 3.
[00042] Altogether, a considerable improvement as compared
to available systems is already attained by means of the
proposed solution in that the safety against overheating is
improved by means of the separate cooling circuitry. A smart
constructive arrangement of the pipe coils required for the
cooling, which does not require any separate holding devices,
is additionally provided. It is furthermore advantageous that
the components of the burner holding devices, such as cooling
coils or insulating materials, can be replaced.
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List of Reference Numerals
1 outer cooling circuit for the main burners
2 inner cooling circuit for the start burner
3 start burner cooling section
4 start burner
5 main burner
6 main burner cooling section
7 overall system burner holding device
8 entrained flow reactor
9 joint cooling water supply
10 joint cooling water discharge
11 main flange
12 casing of the cooling device in the burner holding
device
13 outer ring
14 wound collar of the cooling jacket
14' cooling jacket of the reactor
15 annular gap
16 annular space
17 insulating loose material
18 refractory concrete layer heat conducting
19 lightweight refractory concrete layer insulating
sealing cord package
