Note: Descriptions are shown in the official language in which they were submitted.
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18632P0005CA01
Storage Container and Furnace
The invention relates to a storage container for solid fuels according to
the preamble to claim 1, and a furnace with a storage container attached
thereto.
Various devices for automatically loading wood furnaces with billet
wood are known from the prior art. For example, in US 4,539,915 a device is
described, with which logs of wood are loaded into a boiler furnace from the
top.
FR 2 668 581 describes an automatic loading device with which billet
wood is conveyed in a direction via inclined surfaces.
AT 399 388 describes a furnace which has a storage container for
firewood at its top, from which the furnace can be loaded by the force of
gravity.
In addition, numerous possibilities exist for the automatic loading of a
combustion furnace with lumpy products processed in a defined manner, such
as pellets, wood chips, etc. A large number of possibilities for conveying
uniform lumpy products of this type exist.
One method of loading billet wood that has heretofore been quite
popular has been to lay wood billets in by hand based upon the heat
requirement. Because the heat requirement cannot be predicted precisely,
and/or in order to avoid having to continuously reheat the furnace, the fill
volumes of such furnaces are usually relatively large. Surplus energy must,
however, be released to a buffer or water storage container. This is
economically feasible only in certain cases, however, because in addition to
the initial costs of acquisition, the space requirement, etc, the heat loss
from
such buffer storage containers is considerable. Solid fuel furnaces of this
type
must be loaded multiple times per day at full heating operation. Especially
during the transition period, when little heat energy is required, selective
heating is not easily feasible.
The object of the invention is therefore to devise a storage container
which can easily and simply be attached to a furnace, and with which solid
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fuels, especially billet wood, can be conveyed without interruption and
automatically to the furnace, or with which the furnace can be loaded in this
manner. A device of this type should be mechanically simple in structure and
economical, and should run in continuous operation without interruption.
These objects are attained with the characterizing features of claim 1.
With the characterizing features of claim 1, a device which is
mechanically very simple in structure is devised, which is not susceptible to
malfunction and experiences only low levels of wear during operation.
Accordingly, it operates reliably, and all types of maintenance can be
performed very easily on it.
The advantageous characterizing features according to claim 2 ensure
a structurally simple form.
To automatically bring the wood billets to the correct loading position, it
is advantageous to provide the characterizing features of claim 3. This
technically simple measure ensures the reliable loading of the furnace.
To ensure a complete unloading or emptying of the conveyor loop, it is
advantageous to provide the characterizing features of claim 4. When
combined with the characterizing features of claim 3, the conveyor loop can
be emptied completely of billet wood in a simple and rapid manner, which is
very important especially when repair work is necessary.
The conveyor loop can advantageously be comprised as a wide mat or
as a plurality of individual belts, according to the characterizing features
of
claim 5. This way, the nature and dimensions of the billet wood can be taken
into consideration.
In order that the length of the conveyor loop will always be sufficient for
conveyance, it is advantageous to provide the characterizing features of claim
6. With these, the control system will not require lengths that have already
been expended when the conveyor loop is to be raised or lowered.
The turning axes are configured according to the characterizing
features of claim 7 to permit the advantageous movement of the conveyor
loop.
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In this respect, it is particularly advantageous to provide the
characterizing features of claim 8, whereby the conveyor loop can be raised
and lowered or tightened and loosened.
A very simple embodiment is provided by the characterizing features of
claim 9. The characterizing features of claim 9 ensure the advantage that the
heating material is always provided at a specific height by the two
independent drives, allowing the control as the wood is being conveyed in the
direction of the furnace to be very precise and exact.
To keep the conveyor loop continuously taut depending upon its
unloaded state, it is advantageous to provide the characterizing features of
claim 10.
The characterizing features of claim 11 create the advantage that the
loading process can be controlled so as to effect a controlled conveyance.
The characterizing features of claim 12 ensure a further control
possibility and form a closure or a possibility for sealing the storage
container.
An advantageous type of attachment or opening is ensured by the
characterizing features of claim 13.
The characterizing features of claim 14 ensure that a sort of
intermediate position is created, in which the wood from the storage container
which has reached the discharge door can be temporarily stored
intermediately.
The door detector according to claim 15 prevents an uncontrolled
reverse conveyance, or causes the door to open only when wood is actually
resting on the discharge door.
This is ensured by the characterizing features of claim 16, wherein this
is also reported back to the control elements of the storage container.
According to claim 18, a type of sluice is formed between the storage
container and the furnace, which enables an advantageous loading and
control of the furnace. The sluices are advantageously controlled according
to claim 18 in such a way that at least one is always closed during operation.
In this way, even in the event of a disruption, such as a loss of electric
power,
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for example, it can be ensured that one of the two discharge doors always
prevents smoke or other exhaust gases from escaping.
In this respect it is advantageous to configure the characterizing
features of claim 19.
For the simple filling of the conveyor loop, it is advantageous to provide
the characterizing features of claim 20.
The characterizing features of claim 21 permit the advantage of
supplementary support for the conveyor loop, especially when it is heavily
loaded. In this manner, the maximum sag or size of the conveyor loop is also
limited or predetermined. This is intended to prevent the conveyor loop from
tearing when fully loaded, and/or to define the maximum fill capacity.
The characterizing features of claim 22 show a particularly stable and
simple method for mounting the support frame.
The object of the invention is further to provide an automatically
loadable furnace or a heating system. This object is attained with the
characterizing features of claim 23.
The characterizing features of claim 23 describe an advantageous
configuration comprising a furnace and a storage container according to the
invention. A device of this type has the advantage that an automatic
conveyance of the fuels is possible, and the fuels can be reloaded or ignited
at the most suitable time.
The sluice module according to claim 24 represents an advantageous
connection between furnace and storage container. In this manner, safety is
increased and/or control possibilities are expanded.
The furnace is advantageously structured according to the
characterizing features of claim 25.
To further improve the control system and to ensure additional
adjustment possibilities, it is advantageous to provide a fill level detector
in the
furnace, according to claim 26.
The advantageous coupling of the control systems according to claim
27 produces an automatic adjustment of heating operation over an extended
period of time.
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With the characterizing features of claim 28, an automatic heating
operation over an extended period of time is possible.
Further advantages and embodiments of the invention are found in the
description and in the attached set of drawings.
The invention is illustrated schematically within the context of
exemplary embodiments in the set of drawings, and will be described in what
follows by way of example, with reference to the drawings.
Fig. 1 shows an overall view of a furnace with a storage container
attached to it upstream.
Fig. 2 shows a detailed view of the storage container from the side.
Fig. 3 shows a furnace with a storage container attached to it
upstream, in its fully loaded state.
Fig. 4 shows a furnace with a storage container attached to it
upstream, in a partially emptied state.
In Fig. 1 a heating system is shown, which comprises a storage
container 20 according to the invention and a furnace 40, which are
operationally connected to one another and/or are coupled together via a
sluice module 30.
The storage container 20 is positioned spatially separate from the
furnace 40. A discharge opening 12, as the sole opening in the storage
container 20, leads from the storage container 20 into the sluice module 30
and from there to the furnace 40.
The storage container 20 has a conveyor unit, with which fuels 17 can
be conveyed to the furnace 40. This conveyor unit is configured according to
the invention in the form of a flexible and pliable conveyor loop 1. The fuels
17 can be placed on this conveyor loop as shown in Fig. 2.
The conveyor loop is comprised, as shown in Fig. 2, of two individual
belts which extend parallel to one another, spaced somewhat from one
another. The conveyor loop 1 can also have a different form, especially it can
be configured as a single-piece wide mat, or as a wide belt, in which case
there is no intermediate space between the individual belts. The conveyor
loop 1 can also be configured as a chain or may have a net-like structure.
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The conveyor loop 1 is mounted or suspended at its upper area
between two turning axes 3 and 4. When it is loaded with fuels, as shown in
Fig. 1, the conveyor loop 1 forms a sack-like shape and sags downward.
Between these two turning axes 3 and 4, a discharge area 7 which is open
toward the top is formed, via which the fuels can be discharged from the
conveyor loop 1.
The storage container 20 is substantially held in a housing, which is
bordered on both sides by side walls 22. The depth of the storage container
20 is a few centimeters shorter than the depth of the combustion chamber to
enable safe loading. The length of the billet wood should advantageously be
selected such that it corresponds to the depth of the storage container 20,
i.e.,
it must be ensured that the firewood 17 or the billet wood can be stacked, and
can be placed on the conveyor loop 1 as shown in Fig. 2. Deviations of
approximately 20% from the maximum length will not affect functioning. To
rule out malfunctions in the automatic conveyance, it is advantageous to sort
out oversized and severely misshapen billet wood 17 or wood with protruding
branches, along with undersized or brittle wood, in advance. Fuels which
have the customary dimensions and geometries, such as are created by the
splitting of round and squared pieces of wood, are suitable for loading.
Also provided in the storage container 20 are drive or traction means,
with which the conveyor loop 1 can be moved and/or tightened or loosened,
and/or with which the length of the conveyor loop 1 can be shortened or
lengthened and its sag can be decreased or increased. In this manner, with
the corresponding movement of the drive or traction means, the sack-shaped
cross-section of the conveyor loop 1 is decreased in size, and the fuels 17
are
moved upward in the direction of the discharge area 7. This process is
reversible.
In Fig. 1 and also in Fig. 3 and 4 it is apparent that a turning axis 3 is
provided, positioned on the left side of the storage container 20, remote from
the discharge opening 12, along with a turning axis 4, which is close to the
discharge opening 12 or the furnace. These two turning axes 3, 4 also define
the size of the discharge area 7.
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The right turning axis 4 forms the upper unloading edge 19, which the
fuels 17 must overcome in order to be discharged in the direction of the
sluice
module 30 or to the furnace 40.
The turning axis 3 is positioned relatively higher than the turning axis 4 in
relation to the conveyor loop 1. The direction in which the fuels 17 can be
removed from the conveyor loop 1 is thereby predetermined, namely in the
direction of the discharge opening 12, via the unloading edge 19.
In Fig. 1 and 3, the conveyor loop 1 is fully loaded with fuel 17 and is
shown at its maximum sag. When fuel 17 is discharged from the conveyor
loop 1 or when traction is exerted via the drive means, its cross-section and
length are decreased in size and the conveyor loop 1 takes on a form as
shown in Fig. 4.
To fully empty the conveyor loop 1, a further reduction in its sag is
necessary. In its fully tightened and unloaded state, the conveyor loop 1
forms a flat surface between the turning axis 3 and the turning axis 4. Fuels
17 cannot remain in place on this inclined surface and slide automatically
over
the unloading edge 19 through the discharge opening 12 into the sluice
module 30.
In the present embodiment, the conveyor loop 1 according to Fig. 1
and 3 is configured as a continuous belt, wherein numerous additional turning
axes 16 are provided, which effect the continuous guidance of the conveyor
loop 1 in the storage container 20. Beginning at turning axis 3, which is
remote from the furnace, the conveyor loop 1 is diverted 90 downward via a
first turning axis 16. There, a tension weight is located, configured as a
turning axis, which can be moved downward as shown in Fig. 4. From this
tension weight 2, the conveyor loop 1 extends upward again to a second
turning axis 16, where it is turned 180 and runs in the direction of the base
of
the storage container 20. There it is turned 90 toward the right by a third
turning axis, to the opposite corner of the storage container 20, where it is
again directed 90 upward by a fourth turning axis 16, running along the
boundary wall of the furnace 40 or the sluice 30. At the uppermost point, the
turning axis 4 that is near the discharge opening 12 is located, at which the
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conveyor loop 1 defines the unloading edge 19, and is turned 180 , wherein
this turning and the turning on the opposite turning edge 3 form the sack-
shaped sagging of the conveyor loop 1 for loading the fuel 17. The tension
weight 2 can be moved upward and downward, and causes a shortening or
tightening of the available length of the conveyor loop 1. When the tension
weight 2 is pulled downward, the sag in the conveyor loop 1 is reduced.
The turning axes 16 and the turning axes 3 and 4, which are
respectively located near and remote from the furnace, can be either freely
rotating turning rollers or reels, or rigid, smooth turning bars, along which
the
conveyor loop 1 can glide. The turning axes can also be equipped with
means for improving grip, such as teeth or projections, for example, in order
to produce an effective working connection, especially if the conveyor loop 1
is configured as a net or a chain.
The turning axes 3, 4, 16 can be configured as drive or traction means,
wherein in the present embodiment the turning axes 3 and 4 are motor driven.
However, the drive for the conveyor loop can also be embodied as an
independent drive, which is attached to the conveyor loop at some point.
The drives of the turning axes 3 and 4 operate independently of one
another. In this manner, the left and the right upper sides of the conveyor
loop 1 can be lowered and/or raised independently of one another. This
creates a very effective option for controlling the delivery of the firewood
17.
In Fig. 3, a level detector 6 is provided in the open discharge area 7 of
the conveyor loop 1. This level detector 6 can be a mechanical or electronic
detector, which is equipped, for example, with light elements or sensors.
When the level detector 6 is triggered by the fuels 17 reaching a certain
height, then the movement of the conveyor loop 1 and/or the drive or the
traction means is halted or reversed for a certain amount of time.
The fuels 17 can be delivered from the storage container 20 via a
discharge opening 12 located in the top right area of the storage container
20.
This discharge opening 12 is equipped with an upper discharge door 9, which
can be closed. This upper discharge door 9 is mounted on the upper cover of
the storage container 20 via a baffle plate 5, with the joint of the upper
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discharge door 9 being located on said baffle plate 5. In this manner, the
upper discharge door 9 can be opened by pivoting downward.
The upper discharge door 9 and the baffle plate 5 form a shape like a
container, in which fuels 17 that fall over the unloading edge 19 come to
rest.
Thus in the area of the upper discharge door 9, an intermediate storage
position is formed, which intermediately stores the fuels 17 for a certain
period
of time.
In the area of the upper discharge door 9, a door detector 8 is
provided, which detects whether fuels 17 are present in the area of the upper
discharge door.
Below the upper discharge door 9, a lower discharge door 10 is
provided, which is also capable of opening by pivoting downward. This door
is positioned in the area of the sluice module 30, and forms the direct
connection between the furnace 40 and the sluice module 30. With these two
discharge doors, the upper discharge door 9 and the lower discharge door 10,
a type of sluice or sluice system is formed. At least one of these two
discharge doors 9, 10 is always closed. The discharge doors 9, 10 are
configured to be smoke tight and/or insulated against exhaust gases, and are
sealed, so that no exhaust gases can escape from the furnace 40 in the
direction of the storage container 20.
Further, an electronic or computerized control mechanism is provided,
which controls the diametrically opposite movement of the upper discharge
door 9 and the lower discharge door 10, and also opens the upper discharge
door 9, halts the drive or traction means, and lowers the conveyor loop 1
somewhat, if applicable, when the door detector 8 is triggered. The
mechanical drive for the discharge doors 9, 10 is configured as self-locking,
i.e., even in the event of a loss of power, the discharge doors 9, 10 are
prevented from opening unintentionally.
In the area below the sluice module 30, below the lower discharge door
10, the combustion space or the combustion chamber 25 of the furnace 40 is
located. The fuels 17 that are placed in the furnace 40 rest upon a grate 14,
where they can be ignited via an ignition system 15, especially an automatic
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ignition system. A fill level detector 13 is provided in the combustion
chamber
25, which indicates how much fuel 17 is present in the combustion chamber
25. This fill level detector 13 is connected to the device for controlling the
storage container 20, especially to the device for controlling the conveyor
loop
1. When the fill level detector 13 is triggered, the movement of the conveyor
loop 1 is halted or reversed. Adjacent to the combustion chamber 25, a heat
exchanger 11 is attached, which is heated by the heat from the combustion
chamber.
It is clearly apparent that the storage container 20 is much larger than
the combustion chamber 25 and has a greater volume.
In the storage container 29 [sic - Translator], a rectangular support
frame 21, comprised of three straight plate-like sheets connected to one
another, is provided. This frame encompasses the conveyor loop 1 on the
outside and limits the maximum sag of the conveyor loop 1 at its sides and its
bottom, and/or defines the maximum size of the conveyor loop 1. In the
discharge area 7, which is open toward the top, no plate is provided in the
support frame 21, i.e., the support frame 21 is also open toward the discharge
area 7. The side edges of the support frame 21 are welded to the two side
walls 22 of the storage container 20. Thus it also determines the depth and/or
width of the storage container 20.
As an alternative to the upper discharge door 9, or as an alternative to
the upper discharge door 9 and the lower discharge door 10, a bucket wheel
sluice or a bucket wheel drum may be provided, which conveys the fuels 17
from the discharge area 7 in the direction of the combustion chamber 25.
In practical applications, the furnace 40 with the storage container 20 is
operated as follows:
The conveyor loop 1 is loaded with fuel, especially billet wood 17,
through the fill doors 18. The fill doors 18 are then closed. When the furnace
control system emits a signal indicating that heating material is required,
the
conveyor loop 1 is raised and its sag is reduced. This is accomplished via
activation of the motor-driven turning rollers 3 and 4. In this manner, the
firewood 17 is also raised, until it falls over the unloading edge 19 to the
upper
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discharge door 9. When the fuel 17 reaches the maximum defined height, the
level detector 6 is triggered and the movement of the turning rollers 3 and 4
is
halted or even reversed.
As long as no fuel 17 is located on the upper discharge door 9 and the
detector 8 is not triggered, the conveyor loop 1 continues to be decreased in
size. Once a fuel 17 is detected by the door detector 8, the movement of the
turning rollers 3 and 4 is halted, and the conveyor loop 1 is lowered again
somewhat, in order to prevent uncontrolled reverse conveyance. The upper
discharge door 9 then opens somewhat and passes the firewood 17 on to the
lower discharge door 10. Before the lower discharge door 10 opens, the
upper discharge door 9 is closed again. Only then does the lower discharge
door open 10, delivering the firewood 17 into the combustion chamber 25.
The lower discharge door 10 then closes again, and the transport of billet
wood to the upper discharge door 9 starts again, as soon as the control
system for the furnace 40 requests heating material. The control system is
triggered, as described above, by the fill level indicator 13 in the
combustion
chamber 25. The automatic ignition device can also be combined with the
system for controlling the furnace 40 and the storage container 20.
The present device is capable of conveying not only billet wood having
a length of 20 to more than 100 cm, but also lumpy fuels, such as coke, coal,
pressed sawdust, wood pellets, etc. It is necessary only for the conveyor loop
1 and the detectors 6, 8 to be configured appropriately for the fuel 17.
The fuels 17 are transported from the storage container 20 into the
combustion chamber 25 of the furnace 40 automatically based upon energy
requirements. The degree of efficiency of such systems is increased,
because the control system of the furnace 40 operates at an optimum
combustion process using a defined quantity of heating material. Overfilling
is
thereby excluded. Any "quenching" of the combustion in the event of surplus
energy, which is otherwise necessitated with such solid fuels furnaces, is
eliminated. This produces an advantageous effect on the degree of
efficiency, the exhaust gas values, and the maintenance periods for such
systems.
