U.S. patent application number 13/124469 was filed with the patent office on 2011-12-08 for conveyor device for combustion boilers.
This patent application is currently assigned to CLYDE BERGEMANN DRYCON GMBH. Invention is credited to Carsten Wilhelm Michelbrink, Rafael Moreno Rueda.
Application Number | 20110297060 13/124469 |
Document ID | / |
Family ID | 41698100 |
Filed Date | 2011-12-08 |
United States Patent
Application |
20110297060 |
Kind Code |
A1 |
Moreno Rueda; Rafael ; et
al. |
December 8, 2011 |
CONVEYOR DEVICE FOR COMBUSTION BOILERS
Abstract
A device, which conveys and handles material from a combustion
boiler, includes at least one conveyor belt and a housing
surrounding the conveyor belt. The conveyor belt includes at least
one horizontal collection area and a handling area. The housing
includes at least one outlet for the material. Furthermore, the
handling area has a first length of at least 10 m and an
inclination of at least 38.degree.. Some arrangements relate to a
corresponding combustion plant and to a method for handling hot
ash.
Inventors: |
Moreno Rueda; Rafael;
(Alpen, DE) ; Michelbrink; Carsten Wilhelm;
(Wesel-Bislich, DE) |
Assignee: |
CLYDE BERGEMANN DRYCON GMBH
Wesel
DE
|
Family ID: |
41698100 |
Appl. No.: |
13/124469 |
Filed: |
October 2, 2009 |
PCT Filed: |
October 2, 2009 |
PCT NO: |
PCT/EP2009/062803 |
371 Date: |
August 9, 2011 |
Current U.S.
Class: |
110/344 ;
110/165R; 198/804; 198/832; 198/846 |
Current CPC
Class: |
F23J 2900/01007
20130101; F23J 2900/01003 20130101; F23J 1/02 20130101 |
Class at
Publication: |
110/344 ;
198/804; 198/846; 198/832; 110/165.R |
International
Class: |
F23J 1/02 20060101
F23J001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2008 |
DE |
10 2008 052 085.3 |
Claims
1. A device for conveying and treating material from a combustion
boiler, having at least one conveyor belt and a housing surrounding
the conveyor belt, wherein the conveyor belt has at least one
horizontal collecting region and a treatment region, and the
housing has at least one outlet for the material, and furthermore
the treatment region has a first length of at least 10 m and a
slope of at least 38.degree..
2. The device according to claim 1, wherein the treatment region is
arranged at a maximum distance of 5 m from the end of the
collecting region.
3. The device according to claim 1, wherein the collecting region
and the treatment region are connected via a deflecting region,
wherein the housing forms a reservoir for material in the
deflecting region above the conveyor belt.
4. The device according to claim 1, wherein the conveyor belt is
embodied with at least one of the following properties: a width of
the conveyor belt of at least 0.8 m, webs running along the width
and having a web height of at most 200 mm, webs which are arranged
along the extent of the conveyor belt at a distance apart of at
least 0.65 m and which run along the width.
5. The device according to claim 1, wherein an air supply for an
air flow toward the treatment region of the device is provided in
the region of the at least one outlet.
6. The device according to claim 1, wherein cross members are
arranged below the conveyor belt in the horizontal collecting
region of the conveyor belt.
7. The device according to claim 1, wherein the conveyor belt is
connected to a chain drive.
8. The device according to claim 1, wherein the treatment region of
the device has various slopes.
9. A plant comprising at least one combustion boiler, having at
least one bottom opening for delivering material, and at least one
device for conveying and treating material from a combustion
boiler, each device having at least one conveyor belt and a housing
surrounding the conveyor belt, wherein the conveyor belt has at
least one horizontal collecting region and a treatment region, and
the housing has at least one outlet for the material, and
furthermore the treatment region has a first length of at least 10
m and a slope of at least 38.degree., and wherein the collecting
region is arranged below the at least one bottom opening, and at
least one silo for the material is provided below the outlet.
10. The plant according to claim 9, wherein at least one comminutor
for the material is provided between the outlet of the housing and
the at least one silo.
11. The plant according to claim 9, wherein data acquisition means
are provided at least in the combustion boiler or in the device,
said data acquisition means being connected to a controller which
is connected to a drive of the conveyor belt.
12. A method for conveying and treating hot ash of a combustion
boiler, comprising at least the following steps: a) delivery of the
hot ash from a combustion boiler onto a horizontal collecting
region of a conveyor belt arranged in a housing, such that the ash
is transported with varying dwell time in the collecting region, b)
rearranging the hot ash, such that at least some of the ash is held
back with a shorter dwell time in the collecting region, c)
transporting the ash in an inclined treatment region having a first
length of at least 10 m and having a slope of at least 38.degree.,
an opposed air flow for cooling the ash being generated, and d)
discharging the ash from the housing.
13. The method according to claim 12, wherein the hot ash is
portioned at least during step b) or c).
14. The method according to claim 12, wherein the comminuting of
the ash and the storing of the ash in a silo directly follow step
d).
15. The method according to claim 12, wherein the speed of the
conveyor belt is varied during the operation of the combustion
boiler.
Description
[0001] The present invention relates to a device for conveying and
treating material from a combustion boiler, having at least one
conveyor belt and a housing surrounding the conveyor belt. The
invention is used in particular in plants having at least one
combustion boiler, for example plants for burning fossil fuels
and/or waste combustion plants. In addition, the invention also
relates to a corresponding plant and to a method for conveying and
treating hot ash of a combustion boiler.
[0002] During the transport of slag, ash or combustion residues,
designated below as "material", it is especially important to
firstly achieve specific solidification or consolidation of the
hot, partly still molten materials, such that, in particular,
conveying or further processing of these materials is made possible
after extraction from the combustion boiler. In addition, it is
also desirable to utilize the energy still present in the hot
material and thus improve the overall efficiency of the plant or of
the combustion boiler.
[0003] After it was first assumed that quenching in a water bath
("wet discharge") is necessary for conveying the hot materials,
"dry extraction systems" have also gained acceptance since the
nineteen nineties. In this case, the hot material is put onto
conveyor belts and transported further there, wherein, if need be,
post-combustion or specific cooling of the hot material is also
partly carried out on the conveyor belt. In this case, it will
immediately become obvious that the materials used here, in
particular the conveyor belt, have to withstand the high
temperatures, the corrosive environment and/or the high mechanical
loading. These conveyor belts are usually constructed to be
encapsulated relative to the external environment and therefore
have a housing which prevents the combustion gases which are still
produced during the treatment of the material from being able to
easily escape into the environment. In addition, the combustion
boilers are mainly operated with a slight vacuum, and so the
combustion gases produced by the material are drawn off toward the
combustion boiler by a corresponding suction.
[0004] For an extraction device which is useful from the energy
point of view and is specifically set up with regard to the cooling
behavior, reference may be made to EP 0 471 055 B1. In this
document, it is explained that it is useful to cool the hot
material in two separate cooling stages with an interposed
comminuting step for the hot material. In the process, in
particular a cooling air flow according to the counterflow
principle is to be realized, said cooling air flow being provided
at the end of the second cooling stage and at the end of the first
cooling stage. Special effects are explained in this document with
regard to the comminution of the hot material and the rearranging,
such that a more effective operation of the combustion boiler
overall is to be made possible.
[0005] In this construction, however, allowance is to be made for
the fact that a considerable construction space regularly has to be
made available for this purpose. In addition, the fact that an
increased cost in terms of apparatus is necessary, especially as a
result of the provision of the comminuting stage, and, with regard
to the coupling of the systems, special requirements are imposed on
the tightness of these systems, also at the high thermal and/or
dynamic alternating stresses, must not be ignored.
[0006] Proceeding therefrom, an object of the present invention is
to at least partly solve the problems described with respect to the
prior art. In particular, a device for conveying and treating
material from a combustion boiler is to be specified, said device
being of simple construction and making possible effective
conversion of fuels in the material in terms of energy. In
addition, a plant is also to be specified with which combustion of
the material is achieved with high efficiency, wherein in
particular specific post-combustion of the material on the device
for conveying and treating material is to be effected. Finally, a
method for conveying and treating hot ash of a combustion boiler is
also to be specified, with which method the abovementioned aims can
likewise be at least partly achieved.
[0007] These objects are achieved with a device according to the
features of claim 1 or with a plant having such a device according
to the features of claim 9. Furthermore, these objects are achieved
by a method for conveying and treating hot ash of a combustion
boiler comprising the steps according claim 12. Advantageous
configurations of the invention are specified in the respective
dependent claims. It should be noted that features stated
individually in the claims can be combined in any desired,
technologically appropriate manner and show further configurations
of the invention. The description, in particular in connection with
the figures, explains the invention and indicates additional
exemplary embodiments.
[0008] The device according to the invention for conveying and
treating material from a combustion boiler has at least one
conveyor belt and a housing surrounding the conveyor belt, wherein
the conveyor belt has at least one horizontal collecting region and
a treatment region, and the housing has at least one outlet for the
material. Furthermore, the treatment region has a first length of
at least 10 m (meters) and a slope of at least 38.degree.
(degrees).
[0009] The device constitutes in particular an "extractor" or an
encapsulated plate conveyor or the like. In any case, the device is
one which realizes "dry" conveying of the material from the
combustion boiler. The term "material" means in particular
combustion residues, in particular ash, which is delivered
(directly) from the combustion boiler onto the conveyor belt. In
the process, the material has, for instance, a temperature within
the range of 600.degree. to 1000.degree. C., in particular within
the region around 800.degree. C. The "combustion boiler" may be,
for example, a boiler embodied as follows: lignite combustion
boiler, coal combustion boiler, garbage combustion boiler.
[0010] The conveyor belt is preferably embodied like a steel plate
conveyor in which a multiplicity of steel plates are arranged in a
row in an articulated overlapping (minimum overlap) manner and are
moved via drives or deflecting rollers. Suitable materials for the
conveyor belt are therefore in particular impact-resistant,
corrosion-resistant, high-temperature steels.
[0011] This conveyor belt is surrounded by a housing. The housing
is mostly constructed in such a way that it can be positioned and,
if need be, fastened directly on a corresponding platform. The
conveyor belt is oriented, positioned and fastened in the housing.
The housing regularly has connecting hatches, for example toward
the combustion boiler. In addition, at least one outlet for the
material is provided. In addition, still smaller passages for
inspection, cooling and/or setting the conveyor belt can be
provided. This housing is also usually produced from steel and is
suitable for permanently withstanding the environmental conditions
described above.
[0012] For the construction of the conveyor belt, it is now further
proposed that said conveyor belt be divided into two different
regions, namely a horizontal collecting region and an inclined
treatment region. The horizontal collecting region is regularly
arranged below the hatch for the combustion boiler and serves to
receive the material falling onto the conveyor belt from above. So
as not to cause any unidirectional rebounding of the material from
the conveyor belt, a substantially horizontal orientation of the
conveyer belt is proposed. In these large plants, it is of course
the case that the horizontal position cannot always be exactly
maintained, and therefore in particular certain tolerance ranges,
for example with a deviating angle of up to +/-5.degree. (degrees)
are acceptable here.
[0013] Whereas the (possibly still burning) material is also
primarily collected on the conveyor belt in this collecting region,
the cooling process or post-combustion process is now primarily
carried out in the treatment region. The latter is first of all to
be embodied with a first length which is at least 10 m. It is
especially preferred that the first length is greater than 30 m or
even at least 50 m. In this connection, a larger length is also to
be preferred in the case of smaller slopes specified here, and vice
versa. The first length of the treatment region is determined in
particular in the extension direction of the conveyor belt. The
first length of the treatment region has in particular an effect on
the cooling distance which can be achieved and on the length over
which the material is transported, without complete reorientation
of the material on the conveyor belt itself. In this respect, the
aim here is to realize an especially large first length.
[0014] Furthermore, it is also proposed that the treatment region
have a slope of at least 38.degree., preferably a slope of at least
42.degree. or even up to 45.degree. relative to the horizontal. In
addition, it is also recommended that the slope selected should not
be greater than 60.degree. or should even be at most 50.degree. in
order to limit the proportion of material slipping down and
therefore in order to protect the device and achieve a desired
transport quantity at normal speeds of the conveyor belt. The slope
proposed here ensures, for example, that especially large and/or
elongated material lumps are brought into an unstable position
during the conveying and therefore, in particular in a specific
manner, these large material lumps slip down again and possibly
burst in the process or can also be cooled or treated from another
side. In addition, the slope also has the advantage that hotter
material can specifically be separated from colder material upon
entering the treatment region and/or specific portioning of the
material to be treated or a uniform distribution of the material
over the conveyor belt can be achieved. The last-mentioned effects
are explained in detail in particular with reference to
developments of the invention below. In effect, however, it should
be noted that the preconditions for a compact device having
especially good properties with regard to the post-combustion of
the material are specified by these simple construction
measures.
[0015] According to a development of the invention, it is proposed
that the treatment region be arranged at a maximum distance of 5 m
(meters) from the end of the collecting region.
[0016] The collecting region normally has an extent of, for
example, 5, 8 or at most 10 m, ash being delivered from the entire
bottom of the combustion boiler. In the case of especially large
combustion boilers, however, this collecting region can also have a
length of, for example, up to 20 m or even 30 m. This now means
that material that is already hot is delivered onto the conveyor
belt from one side and said conveyor belt is repeatedly covered
with new, hot material on its way along the collecting region until
it has finally reached the end of the collecting region, that is to
say the location from which new material is no longer delivered
onto the conveyor belt from above. In the process, the lowermost
layers are regularly substantially solidified more quickly due to
their direct contact with the conveyor belt, in which case it now
has to be feared that the hot material lying above the lowermost
layers will disturb this process. For this reason, rapid transition
to the treatment region at this location is now proposed, wherein
in particular a uniform distribution or rearranging of the hot
material is effected. It is therefore especially preferred that the
treatment region begins, if need be, at an even smaller distance
from the end of the collecting region, for example at a maximum
distance of at most 3 m or even at most 1.5 m.
[0017] Furthermore, it is considered to be advantageous that the
collecting region and the treatment region are connected via a
deflecting region, the housing forming a reservoir for material in
the deflecting region above the conveyor belt. As a rule, the
"deflecting region" constitutes the transition section of the
conveyor belt from the horizontal orientation to the inclined
orientation. The deflecting region is characterized, for example,
by corresponding deflecting rollers at the conveyor belt. In the
deflecting region there is in particular a radius of curvature for
the conveyor belt, whereas a substantially straight running
direction for the conveyor belt can be found in the collecting
region and/or in the treatment region. While the material passes
through the deflecting region, in particular large material and/or
material piled up high is brought into an unstable position, in the
course of which in particular the large materials lying in an
unstable position and/or the hot materials delivered last tend to
slip or roll down again toward the collecting region on account of
the effect of gravitation. This now means that these material
portions collect or knock against one another or rub against one
another in the area of the deflecting region. In order to make
possible or assist this material accumulation, it is proposed that
the housing permits sufficient space for such a material
accumulation on or above the conveyor belt. The term "reservoir"
therefore means in particular a section of the housing which is
substantially free of built-in components and/or even forms a
relatively large clearance width above the conveyor belt. If need
be, the reservoir can also be embodied with reinforced side walls
of the housing and/or with a protective layer and/or a separate
cage in order to guide the material accumulations arising
there.
[0018] The device can now also be developed in such a way that the
conveyor belt is embodied with at least one of the following
properties: [0019] a width of the conveyor belt of at least 0.80 m
(meters), [0020] webs running along the width and having a web
height of at most 200 mm (millimeters), [0021] webs which are
arranged along the extent of the conveyor belt at a distance apart
of at least 0.65 m (meters) and which run along the width.
[0022] The width of the conveyor belt, which is regularly
determined perpendicularly to the extension direction of the
conveyor belt, is thus greater than in current configurations of
the conveyor belt. In particular, a width of at least 1.20 m or
even 2.40 m is to be realized. The width specified here has special
advantages during the distribution of the material on the conveyor
belt, to be precise during the delivery of the material from the
combustion boiler on the one hand and during the rearranging of the
material in the treatment region and/or in the deflecting region on
the other hand. In particular, the ranges of the width are also
preferably between 0.80 m to 1.20 m or 1.20 m to 2.40 m. The aim
here is to distribute the material in particular over the width of
the conveyor belt and thus also achieve, in addition to good
contact with the (cooler) conveyor belt, a large surface for the
contact with the cooling air flow.
[0023] In addition, webs which extend substantially over the width
of the conveyor belt can be provided. The webs limit the movement
of the material on account of the gravitational force in the
treatment region and can therefore help in particular to portion
the material in a certain segment of the conveyor belt. The webs
can be embodied, for example, in the form of perpendicular and/or
oblique metal plates which are attached (in particular rigidly) to
the conveyor belt, for example welded to plates of the conveyor
belt. In order to direct preferably smaller pieces of material in a
predetermined quantity through the treatment region, the web height
should not be too high. It is therefore proposed here that the web
height be limited to 200 mm (millimeters), and it should preferably
not drop below a minimum web height of about 100 mm. Here, the
distance between the webs is advantageously to be selected in such
a way that there is a sufficiently large area for the material to
be treated, in which case the distance can possibly also be at
least 0.80 m or even at least 1.20 m. In any case, surface segments
of the conveyor belt are thus limited, a relatively large area
being provided for the material to be treated, although the layer
height of the material is very limited. Excess material is then
rolled over the webs into the next segment on account of the slope
of the treatment region if sufficient surface is still available
here or the material has burst during the rolling movement. It
should be noted with respect to the webs that said webs, if need
be, can be embodied with a varying web height and/or distance
apart, in particular if at least one web has an additional function
and/or another function, such as, for example, as a driver for
large material lumps, as cleaning scraper below the conveyor belt,
etc.
[0024] As a result of a development of the device, an air supply
for an air flow toward the treatment region of the device is
provided in the region of the at least one outlet. The air supply
is therefore to be set up or positioned in such a way that an air
flow like a counterflow with respect to the transported material
can be realized. The air supply can comprise one or more nozzles,
slots, openings or the like, wherein an active (with positive
pressure) and/or passive (with ambient pressure) provision of air
is generally possible. It is preferred that the air supply
comprises one or more openings in the housing, such that air can be
drawn in (passively) from the environment in particular on account
of the vacuum in the combustion boiler. In this case, it is
furthermore preferred that this air flow is used for the surface
treatment or cooling of the material. In particular, the aim should
be for the air supply in the region of the outlet to constitute the
predominant air supply for the air flow, that is to say that there
are no additional air supplies for an air flow above the material
in particular in the area of the treatment region. This is intended
to ensure that a finally high temperature of the air flow is
achieved over the relatively long treatment region and the large
surface, provided there, of the material, for example a temperature
of above 200.degree. C., for example about 250.degree. C., upon
entry to the combustion boiler. In addition, this relatively
pronounced heating of the air flow over the material distributed
over a large area leads to comprehensive combustion of the residual
constituents of the material, and equally the energy obtained in
the process can be used again via the combustion boiler or the
downstream heat exchangers of the combustion boiler. In this case,
the ratio of air quantity to material quantity should preferably be
within the range of 1.6 to 2.3; in particular, the ratio of the air
quantity entering the combustion boiler to the conveyed material
quantity is about 2 (e.g. air quantity about 6 t/h and ash quantity
about 3 t/h [tonnes per hour]).
[0025] In addition, it is also considered to be advantageous that
cross members are arranged below the conveyor belt in the
horizontal collecting region of the conveyor belt. The cross
members run substantially in the width direction of the conveyor
belt, to be precise below the top section of the conveyor belt,
onto which the material falls. The cross members have in particular
a supporting function, such that an undesirable deformation of the
conveyor belt is avoided even during the delivery of large material
lumps. The cross members can be embodied like beams and/or
plates.
[0026] It is also considered to be especially advantageous that the
conveyor belt is connected to a chain drive. Here, a chain drive
means that the conveyor belt is connected, in particular on both
sides, to a circulating chain. The chain runs, for example, over a
sprocket, which is driven by a corresponding motor. In particular a
rigid and direct drive of the conveyor belt is thus realized. In
particular, the chain drive has the advantage that there is no slip
between the drive movement and the movement of the conveyor belt.
The chain can be constructed with a considerable tensile strength
and is therefore especially suitable for driving high loads. This
drive is therefore especially suitable for the long treatment
regions. In addition, it should be taken into account that such a
chain drive is also relatively robust in the face of the
fluctuating temperature effects. In particular, it is proposed that
the chain drive be embodied with a motor or with a controller at
which a simple and stepless variation of the drive speed or of the
speed of the conveyor belt can be set. In addition, the conveyor
belt itself can also be guided, for example in guides of the
housing, in which case, for example, lateral supporting rollers can
be provided.
[0027] As a preferred development of the invention, it is also
stated that the treatment region of the device has various slopes.
Even though this is explained here in the context of other features
of the invention described here, the provision of a conveyor belt
with a treatment region of varying slope can also be used
independently thereof. Thus, it is in particular stated that a
first slope is realized to begin with, but this first slope is then
varied in at least one following section, that is to say increased
and/or reduced. It may also be possible for a further section
having a horizontal position and/or a negative slope (declivity) to
follow a section having a slope. It is especially preferred that at
least two of the elements--slope, horizontal, declivity--alternate
repeatedly. An (additional) movement is thus induced in the
material, thereby permitting an improved aftertreatment.
[0028] According to a further aspect of the invention, a plant is
proposed which has at least one combustion boiler, having at least
one bottom hatch for delivering material, and at least one device
of the type described here according to the invention, wherein the
collecting region is arranged below the at least one bottom
opening, and at least one silo for the material is provided below
the outlet. In this form of the plant, it immediately becomes
obvious that an especially compact plant for the aftertreatment of
the material from the combustion boiler can be achieved. In this
case, the material is specifically and effectively treated directly
by an individual device; at the same time, the slope, specified
here, of the treatment region enables a silo to be accommodated
directly below the outlet of the device. The term "silo" refers in
particular to a store for the material, for example having a
capacity of at least 400 m.sup.3 of the material, in particular 900
m.sup.3. It is especially preferred that the silo is arranged above
the collecting region of the conveyor belt.
[0029] Furthermore, it is preferred in the case of the proposed
plant that at least one comminutor for the material is provided
between the outlet of the housing and the at least one silo. It may
be appropriate, in particular with the aim of utilizing the
capacity of the silo as effectively as possible, for material
falling from the conveyor belt in the direction of the silo to be
comminuted to begin with. Known mills and/or disintegrators can be
provided for this purpose, and if need be they should be
constructed to be relatively small since the conveyed and cooled
material usually already has a relatively small size on account of
the treatment described above.
[0030] In addition, it is also considered to be advantageous that,
in the plant, data acquisition means are provided at least in the
combustion boiler or in the device, said data acquisition means
being connected to a controller which is connected to a drive of
the conveyor belt. The term "data acquisition means" means in
particular sensors, for example, for determining the constituents
of the combustion gases in the combustion boiler and/or in the
device, temperature sensors or the like. With these data
acquisition means, therefore, information on the current state of
the combustion boiler and/or of the device or of the material
accumulating or being treated there can be obtained. In particular,
the quantity of the material per unit of time, the residual content
of combustible material and/or the distribution of the material on
the conveyor belt can be determined. Depending on this information,
the controller can regulate the drive with due regard to the
information obtained and can therefore cause said drive to move the
conveyor belt more quickly or more slowly. It can therefore also be
ensured, for example, that extensively distributed material having
a low layer height is discharged at different speeds of the
conveyor belt, even at a high load of the combustion boiler, in the
course of which the requisite discharge capacity is maintained.
[0031] Following a further aspect of the invention, a method for
conveying and treating hot ash of a combustion boiler is proposed.
This method comprises at least the following steps: [0032] a)
delivery of the hot ash from a combustion boiler onto a horizontal
collecting region of a conveyor belt arranged in a housing, such
that the ash is transported with varying dwell time in the
collecting region, [0033] b) rearranging the hot ash, such that at
least some of the ash is held back with a shorter dwell time in the
collecting region, [0034] c) transporting the ash in an inclined
treatment region having a first length of at least 10 m (meters)
and having a slope of at least 38.degree. (degrees), an opposed air
flow for cooling the ash being generated, [0035] d) discharging the
ash from the housing.
[0036] The method can be carried out in particular with the device
and/or the plant described here.
[0037] Step a) signifies in particular the fact that the hot ash is
not delivered on a narrowly restricted, local area of the
collecting region but rather over a wide section of the collecting
region. As a result, the hot ash is delivered onto the collecting
region and then passes through the entire collecting region in the
direction of movement of the conveyor belt and is subsequently
covered by further hot ash which finally remains with a shorter
dwell time in the collecting region until it has reached the end of
the collecting region. Consequently, the ash which is transported
only with a short dwell time in the collecting region is positioned
at the top on the ash which has already been delivered beforehand
onto the conveyor belt and in particular is thus cooled directly by
the cool conveyor belt.
[0038] According to step b), the hot ash is now rearranged. The ash
delivered last, which has therefore remained with a shorter dwell
time in the collecting region and accordingly lies at the top, is
now at least partly rearranged, such that in particular entry to
the inclined treatment region is delayed. This rearranging occurs
in particular in the deflecting region of the conveyor belt by the
hot ash being brought into an unstable position and by the ash
lumps which lie at the top or the large ash lumps slipping down on
account of gravitation or rolling over the webs. The aim of this
rearranging is to firstly achieve stable positioning of the ash
lumps as well as a uniform distribution of the ash over the
conveyor belt or comminution of the ash lumps as a result of these
movements (impingement, rubbing, etc.).
[0039] The ash is then transported upward in the inclined treatment
region (step c)), an opposed air flow for cooling the ash being
generated. This air flow therefore flows against the transport
direction of the ash and is in particular brought into contact with
the surface of the hot ash. On account of the small layer height of
the ash, e.g. at most 200 mm (millimeters) or even only 100 mm
(millimeters), the air flow can cool, in an especially effective
manner, the ash and/or if need be also exposed regions of the
conveyor belt, in the course of which the air flow assumes the
temperature and, heated to a relatively high degree, can finally
enter the combustion boiler.
[0040] The discharge of the ash from the housing according to step
d) is effected in particular solely on account of the gravitational
force.
[0041] In addition, in the method proposed here, it is considered
to be advantageous that the hot ash is portioned at least during
step b) or c). That is to say in particular that the quantity of
the hot ash to be discharged is substantially the same in
accordance with the load conditions of the combustion boiler, such
that the distribution and/or the cooling of the hot ash on the
conveyor belt in the treatment region can be specifically set. For
such portioning, in particular large widths of the conveyor belt
and/or webs and/or variable drives of the conveyor belt are
used.
[0042] In addition, it is considered to be advantageous that the
comminuting of the ash and the storing of the ash in a silo
directly follow step d). This means in particular that the
discharged ash falls directly into a comminutor on account of the
gravitational force, is ground there if need be and then falls
(likewise on account of the gravitational force) directly into a
silo, where the ash (substantially completely solidified) can now
be stored. The extensive silo and the solidified ash already being
stored there complete the cooling function for possibly not yet
completely solidified hot ash which has just been discharged.
[0043] As already described several times, it is especially
advantageous to vary the speed of the conveyor belt during the
operation of the combustion boiler. In this case, in particular a
regulated change in the speed of the conveyor belt can take place
as a function of information obtained from the boiler and/or the
device with the conveyor belt.
[0044] The invention and the technical environment are explained in
more detail below with reference to the figures. It should be noted
that the figures show especially preferred embodiment variants of
the invention but are not restricted thereto. In the drawing is
schematically shown:
[0045] FIG. 1: a first embodiment variant of a device,
[0046] FIG. 2: a further embodiment variant of the device,
[0047] FIG. 3: a detail of a further embodiment variant of the
device,
[0048] FIG. 4: an embodiment variant of a plant,
[0049] FIG. 5: a detail of a conveyor belt with material to be
treated,
[0050] FIG. 6: a cross section through a device according to a
further embodiment variant,
[0051] FIG. 7: a device embodied with various slopes, and
[0052] FIG. 8: a chain drive for a device according to the
invention.
[0053] FIG. 1 shows a first embodiment variant of a device 1 in a
side view. In this case, the collecting region 6 is illustrated in
the left-hand region of the device 1. In this collecting region 6,
the housing 5 has, for example, an opening via which the material 2
is delivered onto the conveyor belt 4. In this case, the collecting
region 6 has a second length 32, which in particular is less than
10 m (meters). On account of the transport movement of the conveyor
belt 4, the material 2 is then moved out of the collecting region 6
(to the right in this case) toward a treatment region 7. The
treatment region 7 constitutes a section of the conveyor belt 4 or
of the housing 5 which has a first length 9 of at least 10 m
(meters), but preferably more than 30 m. In addition, the treatment
region 7 is inclined relative to a horizontal 31 with a slope 10.
The slope (or the angle of slope) is preferably within the range of
between 40 and 45.degree. (degrees), but if need be can be selected
to be even steeper. In addition, the conveyor belt 4 is connected
to a drive 30, which in particular is also positioned close to the
outlet 8 for the material 2. The material, which, as explained
later in detail, is therefore burned or cooled in the treatment
region 7, then falls downward at the top end of the conveyor belt 4
through the outlet 8 on account of gravitation and therefore leaves
the device 1.
[0054] In particular the provision of the cooling air flow 21 is
now illustrated in FIG. 2. For this purpose, the device 1 or the
housing 5 is connected (in a sealed-off manner) to a combustion
boiler 3 (indicated here). The combustion boiler 3 can be operated
with a slight vacuum, such that an air flow 21 can be generated by
the provision of an air supply 20 in the region of the outlet 8,
this air flow 21 being formed in opposition to the transport
direction for the material 2. The air flow 21 therefore flows above
the conveyor belt 4 over the material transported there and is
finally sucked into the combustion boiler 3. The large first length
and the slope of the conveyor belt in the treatment region also
ensure that the outlet and the air supply 20 are positioned at a
very high conveying height 33. The conveying height 33 can be in
particular at least 30 m, if need be even up to 50 m. With regard
to the air supply 20, this also has the advantage that air
containing less floor dirt is fed here, thereby further assisting
the cooling process or combustion process in the device.
[0055] Furthermore, it is illustrated in FIG. 2 that the collecting
region 6 substantially forms an end 12 where the delivery of
material by the combustion boiler 3 no longer takes place. It is
now considered to be advantageous to connect the inclined treatment
region 7 as close to the end 12 of the collecting region 6 as
possible, a maximum distance 11 of, for example, 5 m (meters) being
specified here. In this case, the distance 11 is dimensioned, in
particular starting from the end 12, up to the point at which the
deflecting region 13 of the conveyor belt 4 ends.
[0056] In addition, it is considered to be advantageous that an
(enlarged) reservoir 14 is formed with the housing 5 in the section
of the deflecting region 13. Here, in particular, an increased
accumulation of material is to be ensured if need be, the region
between the conveyor belt 4 right up to the housing 5 being free of
built-in components if possible.
[0057] FIG. 3 shows a detail of a further embodiment variant of the
device, namely the turning region of the conveyor belt 4 close to
the collecting region 6. The housing 5 can also be seen there, the
opening toward the combustion boiler also being indicated at the
top right. On the left, a slide 34 forms the closure for the
housing 5, it also being possible, if need be, for material to be
carried along from the bottom of the housing 5 by means of said
slide 34. The conveyor belt 4 in this case is embodied like a metal
plate conveyor. The individual plates 35, which are connected to
one another in an articulated and overlapping manner, can be seen.
The plates 35 have lateral boundary shells, such that material
cannot fall off laterally over the width of the conveyor belt 4. In
addition, the plates 35 are connected to a chain 37, which in this
case is deflected via the sprocket 36. In this arrangement, the
sprocket 36 engages in the individual links of the chain 37. A
corresponding device is driven, the tensioning station 44 for
tensioning the conveyor belt 4 being shown here--the opposite
motor-operated drive can be seen, for example, from FIG. 8. A chain
drive 23 has proved to be advantageous especially for the large
conveying heights and large lengths of the conveyor belt. Also
indicated here are the cross members 22 which support the top part
of the conveyor belt 4 and are thus intended to prevent an
undesirable deformation of the plates 35 as a result of the
impingement of the material from the combustion boiler 3.
[0058] FIG. 4 schematically illustrates a preferred embodiment
variant for a plant 24. The plant 24 now comprises a combustion
boiler 3 (only partly shown), for example a combustion plant for
waste materials and/or fossil fuels. The device 1 is arranged below
the combustion boiler 3 in such a way that the collecting region 6
is positioned below the bottom opening 25 of the combustion boiler
3. The housing 5 is in this case sealed off and if need be fastened
to the combustion boiler 3 by compensators for compensating for the
different thermal expansions. The material 2 thus falls onto the
conveyor belt 4 in the section of the collecting region 6 and is
then rapidly transported into the treatment region 7. In the
treatment region 7, the material 2 is cooled or burned by means of
an air flow 21. The air flow 21 then enters the combustion boiler 3
at a temperature of, for example, at least 200.degree. C.
[0059] The conveyor belt 4 is embodied with a multiplicity of
plates 35, wherein isolated plates 35 have webs 16 which extend
substantially perpendicularly to the plates 35, as indicated in
FIG. 5. The webs 16 now hinder or limit the rolling movements of
the material 2 back in the direction of the deflecting region 13 on
account of gravitation. The webs 16 are in this case provided in
the direction of the extent 18 of the conveyor belt 4 at a distance
19 apart of at least 1 m, preferably at least 2 m or even 3 m.
Large lumps of the material 2 and/or a large accumulation of the
material 2 now slides over the other material and the webs 16 down
into the reservoir 14. In the process, firstly a large surface is
created for the air flow 21, and at the same time the material 2 is
comminuted, if need be, upon impingement in the reservoir 14. The
hotter material, which regularly lies at the top, is also held back
further in the reservoir before it is transported into the
treatment region 7.
[0060] FIG. 6 again schematically shows a cross section through a
further embodiment variant of the invention. The substantially
closed housing 5 is illustrated, in the interior space 24 of which
the conveyor belt 4 is positioned. The conveyor belt 4 is again
embodied with plates 35, wherein the plates 35 illustrated here
have a web 16 which extends over the entire width 15 of the
conveyor belt 4. The web height 17 of the webs 16 is preferably
less than 200 mm (millimeters).
[0061] FIG. 7 schematically illustrates, in a highly simplified
manner, a device 1 in which the conveyor belt 4 is embodied with
sections 43 having various slopes 10. The combustion boiler 3 is
indicated on the left in FIG. 7 and the silo 26 on the right. Here,
the conveyor belt 4 has, in the treatment region, six (6) sections
43 of different forms, namely in the following sequence: first
slope, second slope (greater than the first slope), first
horizontal, third slope (negative, declivity), second horizontal,
fourth slope (like first slope). This figure is also intended to
serve in particular as a schematic diagram and illustrates the
diversity of variations; the actual sequence can be made according
to requirements. In this case, the conveyor belt 4 preferably has
only one drive 30 for the chain drive 23, as indicated at the end
(identified by VIII) and shown enlarged in FIG. 8.
[0062] FIG. 8 now shows a possible embodiment for the positioning
of a drive 30 for the chain drive 23, which is arranged at the end,
identified by VIII, of the conveyor belt 4.
LIST OF DESIGNATIONS
[0063] 1 Device [0064] 2 Material [0065] 3 Combustion boiler [0066]
4 Conveyor belt [0067] 5 Housing [0068] 6 Collecting region [0069]
7 Treatment region [0070] 8 Outlet [0071] 9 First length [0072] 10
Slope [0073] 11 Distance [0074] 12 End [0075] 13 Deflecting region
[0076] 14 Reservoir [0077] 15 Width [0078] 16 Web [0079] 17 Web
height [0080] 18 Extent [0081] 19 Distance [0082] 20 Air supply
[0083] 21 Air flow [0084] 22 Cross member [0085] 23 Chain drive
[0086] 24 Plant [0087] 25 Bottom opening [0088] 26 Silo [0089] 27
Comminutor [0090] 28 Data acquisition means [0091] 29 Controller
[0092] 30 Drive [0093] 31 Horizontal [0094] 32 Second length [0095]
33 Conveying height [0096] 34 Slide [0097] 35 Plate [0098] 36
Sprocket [0099] 37 Chain [0100] 38 Supporting pillar [0101] 39
Truck [0102] 40 Guide roller [0103] 41 Cooling [0104] 42 Interior
space [0105] 43 Section [0106] 44 Tensioning station
* * * * *