U.S. patent application number 16/409311 was filed with the patent office on 2019-08-29 for arrangement and system for feeding biomass material to a treatment process.
This patent application is currently assigned to VALMET AB. The applicant listed for this patent is VALMET AB. Invention is credited to Johan CARLSSON, Patrik PETTERSSON.
Application Number | 20190264386 16/409311 |
Document ID | / |
Family ID | 56151130 |
Filed Date | 2019-08-29 |
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United States Patent
Application |
20190264386 |
Kind Code |
A1 |
PETTERSSON; Patrik ; et
al. |
August 29, 2019 |
ARRANGEMENT AND SYSTEM FOR FEEDING BIOMASS MATERIAL TO A TREATMENT
PROCESS
Abstract
A feeding arrangement for feeding lignocellulosic biomass
material such as annual plant material towards a hydrolysis process
includes at least one transportation device for transporting the
biomass material towards the treatment process; and at least one
tearing roll arranged at a predetermined distance from the at least
one transportation device and being provided with tearing
protrusion. The at least one tearing roll is arranged with a
predetermined distance to the at least one transportation device to
tear off parts of the transported material to provide a
substantially continuous flow of material.
Inventors: |
PETTERSSON; Patrik; (Alno,
SE) ; CARLSSON; Johan; (Alno, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VALMET AB |
Sundsvall |
|
SE |
|
|
Assignee: |
VALMET AB
Sundsvall
SE
|
Family ID: |
56151130 |
Appl. No.: |
16/409311 |
Filed: |
May 10, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15528045 |
May 18, 2017 |
|
|
|
PCT/SE2015/051392 |
Dec 22, 2015 |
|
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16409311 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B02C 18/2266 20130101;
B01J 8/0045 20130101; B02C 18/2283 20130101; B02C 23/02 20130101;
B01J 8/0015 20130101; B02C 18/2216 20130101; D21C 7/06 20130101;
D01G 23/00 20130101; Y02E 50/10 20130101; Y02E 50/16 20130101 |
International
Class: |
D21C 7/06 20060101
D21C007/06; B02C 23/02 20060101 B02C023/02; D01G 23/00 20060101
D01G023/00; B02C 18/22 20060101 B02C018/22; B01J 8/00 20060101
B01J008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2014 |
SE |
1451638-9 |
Claims
1. A feeding arrangement for feeding lignocellulosic biomass
material towards a hydrolysis or pre-hydrolysis process, the
feeding arrangement comprising: at least one transportation device
for transporting the biomass material towards the hydrolysis or
pre-hydrolysis process; at least one tearing roll arranged at a
predetermined distance from the at least one transportation device
and being provided with tearing protrusions, the at least one
tearing roll being arranged with a predetermined distance to the at
least one transportation device to tear off parts of the
transported material; and a housing provided with an upper inlet
opening for receiving the biomass material and a lower outlet
opening for discharging the biomass material, wherein the at least
one transportation device includes a first and a second revolving
drum arranged in the housing, the first drum revolving in a first
rotational direction and the second drum revolving in a second
rotational direction for transporting the biomass material, wherein
the first and second drums are provided with protrusions and
wherein the first and second drums are arranged to co-rotate with
respect to each other; wherein the at least one tearing roll is
arranged in the housing below the first and second drums seen in a
feeding direction of the biomass material, wherein the at least one
tearing roll is arranged to tear off parts of the material
transported by the first and second drum in order to transport the
material to the outlet opening, and wherein a radius of the tearing
roll is smaller than the radius of the first drum and the radius of
the second drum.
2. The feeding arrangement according to claim 1, wherein a speed of
the transportation device is controlled by a first motor having a
variable speed, wherein a rotation of the at least one tearing roll
is controlled by a second motor having a variable speed and wherein
the speed of the at least one tearing roll is variable
independently of the speed of the transportation device.
3. The feeding arrangement according to claim 1, wherein the
tearing roll is arranged above the outlet opening of the housing
and below a nip between the first drum and the second drum.
4. The feeding arrangement according to claim 1, wherein a
rotational speed of the first and second revolving drum are
controlled by a first motor having a variable speed, wherein a
rotation of the tearing roll is controlled by a second motor having
a variable speed and wherein the speed of the tearing roll is
variable independently of the rotational speed of the first and
second drum.
5. The feeding arrangement according to claim 1, wherein the
tearing roll is arranged such that an outer part of the tearing
roll is located a first predetermined distance from an outer
surface of the first drum and at a second predetermined distance
from an outer surface of the second drum.
6. The feeding arrangement according to claim 5, wherein the first
predetermined distance is equal to or lower than a radius of the
first drum and the second predetermined distance is equal to or
lower than a radius of the second drum.
7. The feeding arrangement according to claim 5, wherein the
tearing protrusions of the tearing roll are cutting elements.
8. The feeding arrangement according to claim 2, wherein the
tearing roll is arranged above the outlet opening of the housing
and below a nip between the first drum and the second drum.
9. The feeding arrangement according to claim 5, wherein the first
predetermined distance is equal to or lower than half a radius of
the first drum and the second predetermined distance is equal to or
lower than half a radius of the second drum.
10. A feeding arrangement for feeding lignocellulosic biomass
material towards a hydrolysis or pre-hydrolysis process, the
feeding arrangement comprising: at least one transportation device
for transporting the biomass material towards the hydrolysis or
pre-hydrolysis process, wherein the at least one transportation
device includes a conveyer belt; and a first tearing roll arranged
at a predetermined distance from the conveyer belt and being
provided with tearing protrusions to tear off parts of the biomass
material; and a second tearing roll arranged at a discharge end of
the conveyer belt and being provided with tearing protrusions to
tear off parts of the biomass material discharged from the conveyer
belt to transport the biomass material to the hydrolysis or
pre-hydrolysis process downstream the conveyer belt.
Description
CROSS-REFERENCE PARAGRAPH TO RELATED APPLICATIONS
[0001] This application is a Divisional Application of U.S.
application Ser. No. 15/528,045, filed May 18, 2017, which is the
National Phase under 35 U.S.C. .sctn. 371 of International
Application No. PCT/SE2015/051392, filed on Dec. 22, 2015, which
claims the benefit under 35 U.S.C. .sctn. 119(a) to Patent
Application No. 1451638-9, filed in Sweden on Dec. 22, 2014, all of
which are hereby expressly incorporated by reference into the
present application.
TECHNICAL FIELD
[0002] The present invention relates to feeding arrangements and
systems for hydrolysis and pre-hydrolysis processes using
ligno-cellulosic biomass material including biomass material such
as annual plants.
BACKGROUND OF THE INVENTION
[0003] High pressure or pressurized systems are typical in
hydrolysis and pre-hydrolysis processes. Feeding of cellulosic
biomass material including annual plants to be treated in a
treatment arrangement, for example, an arrangement for a
pre-hydrolysis process therefore often involves handling of the
material under higher pressures. In such arrangements it is
important to provide a smooth and reliable feeding of the biomass
material in order to prevent and avoid, for example, uneven power
consumption and problems with so called blow-back flow.
[0004] According to prior art solutions, biomass material is
transported to the treatment process via a feeding arrangement such
as a pin drum feeder and further to a conveying device which
conveys the material to the treatment process.
[0005] In typical prior art feeding arrangements, a housing is
arranged with an upper inlet opening for receiving the material and
a lower outlet opening 15 for discharging the material to conveyor.
Revolving drums are provided in the housing to control the
transport and flow rate of the material through the housing. After
the material has passed the revolving drums, the material falls
through the lower outlet opening to the plug screw feeder. It is
important to maintain a smooth and continuous flow of material into
the treatment process. This is crucial in pressurized systems. An
example of a process in a pressurized system is a pre-hydrolysis
process. Such processes are sensitive to changes in the flow rate.
The material is fed to the pin drum feeder from a vertical feeding
chute or similar unit connected to the upper inlet opening of the
housing. An effective and smooth average flow of material into the
pin drum feeder requires that this vertical feeding pipe is
completely filled with material during operation. Hence, when the
feeding pipe is completely filled with material, the flow into the
pin drum feeder will be smooth and continuous. The revolving drums
operate to feed the material through the housing towards the outlet
opening in a controlled manner. During the rotation of the drums
material is forced through the housing and leaves the drums when
the weight of the material exceeds the binding strength of the
material.
[0006] However, if the binding strength of the material increases,
which may occur when the material is compressed, it may result in
that the material is stuck to the drums and leave the drums in
blocks instead of a smooth stream of material. This results in a
discontinuous feeding of material to the conveying device which, in
turn, entails varying power consumption and feeding disruptions
within the conveying device.
[0007] Thus, there is a need for improved feeding arrangements for
feeding lignocellulosic biomass material such as annual plants to a
treatment process and an improved system comprising such a feeding
arrangement and a method for feeding lignocellulosic biomass
material such as annual plants to a treatment process.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide improved
pressurized feeding arrangements and systems for hydrolysis and
pre-hydrolysis processes using lignocellulosic biomass material
such as annual plants.
[0009] Another object of the present invention is to provide
improved pressurized feeding arrangements and systems for
hydrolysis and pre-hydrolysis processes of lignocellulosic biomass
material, such as annual plants, having a low density.
[0010] A further object of the present invention is to provide
improved pressurized feeding arrangements and systems for smoothly
and continuously feeding lignocellulosic biomass material, such as
annual plants, with a high degree of precision to a subsequent
hydrolysis process.
[0011] In the context of the present invention, the term "plug
screw feeder" relates to a feeder comprising a screw or similar
rotating means and which is capable of feeding or transporting
lignocellulosic material through the feeder at increased or
maintained density of the material and that creates an essentially
gas- and fluid-tight plug of the lignocellulosic material towards
the end of the feeder. For example, according to an embodiment of
such a plug screw feeder, a cross-sectional area of the circular
housing of the feeder and the screw diameter decreases in the
feeding direction thereby so as to create a decreasing space
between the screw and the housing and thus resulting in an
essentially gas- and fluid-tight plug of the lignocellulosic
material towards the end of the feeder. According to another
embodiment of a plug screw feeder, the cross-sectional area of the
circular housing of the feeder is constant while and the screw
diameter and screw axis increases in the feeding direction thereby
creating a decreasing space between the screw and the housing and
thus resulting in an essentially gas- and fluid-tight plug of the
lignocellulosic material towards the end of the feeder. As the
skilled person realizes, there are other embodiments of feeders
that achieves this purpose and thus are included within the
definition of the term "plug screw feeder".
[0012] Further, a force-feeding screw that may be used in the
present invention is described in, for example, WO 2013126007.
[0013] According to an aspect of the present invention, there is
provided a feeding arrangement for feeding lignocellulosic biomass
material such as annual plant material to or towards a hydrolysis
or pre-hydrolysis process. The feeding arrangement comprises at
least one transportation device for transporting the biomass
material towards the hydrolysis or pre-hydrolysis process and at
least one tearing roll arranged at a predetermined distance from
the at least one transportation device. The tearing roll is
provided with tearing protrusions and is arranged with a
predetermined distance to the at least one transportation device to
tear off parts of the transported material to provide a
substantially continuous average flow rate of material.
[0014] According to another aspect of the present invention, there
is provided a feeding system for feeding lignocellulosic biomass
material such as annual plant material to or towards a hydrolysis
or pre-hydrolysis process. The system comprises a feeding
arrangement including at least one transportation device for
transporting the lignocellulosic biomass material such as annual
plant material towards the hydrolysis or pre-hydrolysis process and
at least one tearing roll arranged in connection to the at least
one transportation device. The tearing roll is provided with
tearing protrusions and is arranged with a predetermined distance
to the at least one transportation device to tear off parts of the
transported material to provide a substantially continuous average
flow rate of material. A force-feeding screw is coupled to the
feeding arrangement to receive biomass material discharged from the
outlet opening of the feeding arrangement, wherein the
force-feeding screw is arranged to transport the biomass material
to or towards the hydrolysis or pre-hydrolysis process.
[0015] The present invention is based on the insight that by
arranging a revolving tearing roll or grinding roll adjacent to the
transportation device at a predetermined distance from the
transportation device it is possible to restrain the block-wise
feeding of material to the subsequent process, for example, a
force-feeding screw and/or the plug screw feeder, which often
occurs. The tearing roll effectively prevents the material blocks
from forming and instead disintegrates the material to deliver a
smooth and continuous stream of material towards the force-feeding
screw and/or the plug screw feeder.
[0016] According to embodiments of the present invention, a speed
of the transportation device is controlled by a first motor having
a variable speed, wherein a rotation of the at least one tearing
roll is controlled by a second motor having a variable speed and
wherein the speed of the at least one tearing roll is variable
independently of the speed of the transportation device.
[0017] In embodiments where the present invention is implemented in
a system including a conveyer belt, the invention is based on the
insight that by arranging the revolving tearing or grinding roll
adjacent to the discharge end of the conveyer belt and/or above the
transportation side of the conveyer belt it is possible to restrain
the block-wise feeding of material to the subsequent process, for
example, a force-feeding screw and/or the plug screw feeder, which
often occurs. The tearing roll or rolls effectively prevents the
material blocks from forming and instead disintegrates the material
to deliver a smooth and continuous stream of material towards, for
example, a force-feeding screw and/or a plug screw feeder.
[0018] In embodiments where the present invention is implemented in
a system including drum feeder, the invention is based on the
insight that by arranging the revolving tearing or grinding roll
below the revolving drums and above the outlet opening, it is
possible to restrain the block-wise feeding of material to the
force-feeding screw and/or the plug screw feeder which often
occurs. The tearing roll effectively prevents the material blocks
from forming on the drums and instead disintegrates the material
that is collected on the drums to deliver a smooth and continuous
stream of material towards, for example, a force-feeding screw
and/or a plug screw feeder.
[0019] In preferred embodiments of the present invention, the
feeding arrangement is utilized in connection with pressurized
treatment processes posing special requirements on its feeding
arrangement. By the term pressurized is meant that the pressure in
the treatment process exceeds atmospheric pressure. When feeding
lignocellulosic biomass material such as annual plant material to a
pressurized treatment process, the feeding arrangement must be
adapted in such a way that a back flow of high-pressure material or
high-pressure steam from the treatment process is avoided or at
least minimized. In such application it is of outermost importance
that the material in the plug screw feeder is fully compressed and
is constantly feed in a smooth stream to the plug screw feeder to
minimize the risk of high-pressure material or steam going in the
wrong direction, i.e. backwards in relation to the feeding
direction of the biomass material. The present invention provides a
smooth and continuous feeding of material, with a high degree of
precision, to the force-feeding screw and/or the plug screw feeder,
thereby allowing the material in the plug screw feeder to be fully
compressed during operation.
[0020] According to embodiments of the present invention, the drums
of the feeding arrangement are arranged to co-rotate with respect
to each other and thereby transporting the material downwards. In
embodiments, the first and second drum is adapted to able to be
rotated at variable speed in relation to a production flow
rate.
[0021] According to embodiments of the present invention, the
tearing roll is adapted to able to be rotated at variable speed in
relation to a production flow rate. The speed of the tearing roll
and the speeds of the drums are variable independently of each
other.
[0022] According to embodiments of the present invention, a
force-feeding screw such as plug screw feeder is arranged
essentially perpendicular to the feeding arrangement, e.g. a pin
drum feeder, meaning that their respective feeding direction are
essentially perpendicular to each other. In one embodiment of the
present invention, the pin drum feeder is arranged to feed material
to the plug screw feeder from above, i.e. a transverse feed into
the plug screw feeder in relation to its feeding direction.
[0023] According to embodiments of the present invention, the plug
screw feeder is adapted to able to be rotated at variable speed in
relation to a production flow rate set by the feeding arrangement.
In other embodiments, the plug screw feeder is adapted to be kept
at a constant speed being chosen such that the plug screw feeder
has a predetermined degree of filing below the production flow rate
set by the feeding arrangement.
[0024] According to embodiments of the present invention, the
tearing roll is arranged such that an outer part of a tearing
protrusion is at a first predetermined distance from an outer
surface of the first drum and at a second predetermined distance
from an outer surface of the second drum. Protruding pins are
according to embodiments provided on the outer surfaces of the
first and second drums. In embodiments, the first distance and
second distance are equal to or lower than a radius and of the
first and second drum, respectively, and, preferably equal to or
lower than half the radius of the first and second drum,
respectively. Further, a minimum distance between a tip of a pin of
a drum and the outer part of the tearing roll is preferably 1
cm.
[0025] According to embodiments of the present invention, the
radius of the tearing roll is smaller than the radius of the first
drum and the radius of the second drum. The radius of the tearing
roll is defined as the radius of the roll itself (without the
tearing protrusions), and the radius of the first drum and the
radius of the second drum are defined as the radius of the
first/second drums themselves (without any protruding pins). In
other embodiments, the radius of the tearing roll may be defined to
the outer ends or parts of the tearing protrusions, and the radius
of the first drum and the radius of the second drum may be defined
to the outer ends of the protruding pins. In both cases, the radius
of the tearing roll is smaller than the radiuses of the first and
second drums. This is advantageous since it allows the tearing roll
to be placed close to the first and second drums to effectively
tear off parts of the transported material to provide a
substantially continuous average flow rate of material.
[0026] According to embodiments of the present invention, the
transportation device is a conveyer belt. In embodiments, two
tearing rolls are provided, wherein a first tearing roll is
arranged above a transportation side of the conveyer belt to tear
off parts of the transported material and a second tearing roll is
arranged at a discharge end of the conveyer belt to tear off parts
of material being discharged from the conveyer belt. In
embodiments, the rotation of the at least one tearing roll is
controlled by a motor having a variable speed and wherein the speed
of the at least one tearing roll is variable independently of a
transport speed of the transportation device.
[0027] According to embodiments of the present invention, an outer
part of the first tearing roll, which is arranged at a discharge
end of the conveyer belt, is arranged at predetermined distance
from the discharge end of the conveyer belt, wherein the distance
is within a range relative the thickness or height of the layer or
mat of biomass material transported on the conveyor belt.
Preferably, the range is between 0.5.times. the height of the layer
of the transported material and 1.5.times. the height of the layer
transported material, or at least 50 mm.
[0028] According to embodiments of the present invention, an outer
part of the second tearing roll, which is arranged above the
transportation side of the conveyer belt, is arranged at
predetermined distance from the conveyer belt, wherein the distance
is within a range relative the thickness or height of the layer or
mat of biomass material transported on the conveyor belt.
Preferably the range is between 0.5.times. the height of the layer
of the transported material and 1.5.times. the height of the layer
transported material, or at least 50 mm.
[0029] Further advantageous embodiments of the device according to
the present invention and further advantages with the present
invention emerge from the detailed description of embodiments.
[0030] In the above, an arrangement and a system for feeding
lignocellulosic biomass material towards a hydrolysis or
pre-hydrolysis process have been described. It is understood from
this wording that the arrangement and system are suitable for
feeding biomass material towards a hydrolysis or pre-hydrolysis
process, i.e. in the direction of such a process, but not
necessarily directly to the process. Thus, the biomass material may
be fed to a pre-hydrolysis process, the hydrolysis process/reactor
itself, or even another process downstream of the hydrolysis
process/reactor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The present invention will now be described, for exemplary
purposes, in more detail by way of embodiments and with reference
to the enclosed drawings, in which:
[0032] FIG. 1 is a schematic partial side view of a feeding
arrangement in which the present invention can be arranged;
[0033] FIG. 2 is a schematic side view of an embodiment of a
feeding arrangement according to the present invention;
[0034] FIG. 3 is a schematic side view of an embodiment of a
feeding system according to the present invention;
[0035] FIG. 4 is a schematic side view of another embodiment of a
feeding arrangement according to the present invention;
[0036] FIG. 5 is a schematic side view of a further embodiment of a
feeding arrangement according to the present invention;
[0037] FIG. 6 is a schematic detailed view of the tearing roll and
the revolving drums;
[0038] FIG. 7 is a schematic view of a further embodiment of a
tearing roll in accordance with the present invention;
[0039] FIG. 8a is a schematic view of another embodiment of a
tearing roll in accordance with the present invention;
[0040] FIG. 8b is a cross-sectional view of the embodiment of the
tearing roll shown in FIG. 8a.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0041] In the drawings, similar or corresponding elements are
denoted by the same reference numbers.
[0042] For the purpose of this disclosure, the term longitudinal
refers to the direction along which a body, part or element has its
greatest extension. Further, when the term longitudinal is used in
connection with the axes of screws, the longitudinal axis
corresponds to the rotational axis of the screw.
[0043] With reference first to FIG. 1, a feeding arrangement in
which the present invention can be arranged or implemented will be
discussed. The pin drum feeder 10 comprises a housing 12 with an
upper inlet opening 14 for receiving the material and a lower
outlet opening 15 for discharging the material to the plug screw
feeder 17. Revolving drums 18 are provided in the housing 12 to
control the transport and flow rate of the material through the
housing. After the material has passed the revolving drums, the
material falls through the lower outlet opening to the plug screw
feeder. The material is fed to the pin drum feeder from a vertical
feeding chute or similar unit connected to the upper inlet opening
of the housing 12. An effective and smooth flow of material into
the pin drum feeder requires that this vertical feeding pipe is
completely filled with material during operation. Hence, when the
feeding pipe is completely filled with material, the flow into the
pin drum feeder will be smooth and continuous. The revolving drums
operate to feed the material through the housing towards the outlet
opening in a controlled manner.
[0044] FIG. 2 is a schematic cross-sectional side view illustrating
an example feeding arrangement according to an exemplifying
embodiment of the present invention. The feeding arrangement 20 for
feeding lignocellulosic biomass material such as annual plant
material to a treatment process, e.g. a pre-hydrolysis process,
comprises a housing 21 provided with an upper inlet opening 22 for
receiving the biomass material and a lower outlet opening 23 for
discharging the biomass material. The biomass material is fed to
the inlet opening 22 via a feeding chute (not shown) or similar
construction. The feeding pipe may be vertically arranged allowing
the material to fall into the feeding arrangement 20 through the
inlet opening 22. Preferably, the feeding pipe is completely filled
with material thereby delivering a smooth and continuous flow of
material into the feeding arrangement 20.
[0045] A first and a second revolving drum 24, 25 are arranged in
the housing 21. The first drum 24 is arranged to revolve or rotate
in a first rotational direction R.sub.1 and the second drum 25 is
arranged to revolve or rotate in a second rotational direction
R.sub.2. The first drum 24 and the second drum 25 are arranged to
co-rotate with respect to each other and thereby, by rotation of
the first and second drum 24, 25, transport the biomass material
through the housing 21 towards the outlet opening 23 (in FIG. 2 in
a downward direction). In embodiments of the present invention, a
rotational speed of the first and second revolving drum 24, 25 is
controlled by a motor 26 having a variable speed. Preferably, a
rotational speed of the first and second drum 24, 25 is controlled
using the motor 26.
[0046] At least one tearing roll 27 is arranged at a predetermined
distance d1 and d2, respectively, from the first and second
revolving drum 24, 25. The tearing roll 27 is provided with tearing
protrusions 70 (see FIG. 6) and is arranged with a predetermined
distance to the at least one transportation device to tear off
parts of the transported material to provide a substantially
continuous flow rate of material.
[0047] As can be seen in FIGS. 2 and 3, the radius of the tearing
roll 27 is smaller than the radius of the first drum 24 and the
radius of the second drum 25. According to embodiments of the
present invention, the tearing roll 27 is arranged such that an
outer part of a tearing protrusion 70 (see FIG. 6) is at a first
closest predetermined distance d1 from an outer surface 74 (see
FIG. 6) of the first drum 24 and at a second predetermined distance
d2 from an outer surface 75 of the second drum 25. The protruding
pins 66 are according to embodiments provided on the outer surfaces
74, 75.
[0048] In embodiments, the first distance d1 and second distance d2
are equal to or lower than a radius RA1 and RA2 of the first and
second drum, respectively, i.e. d1, d2 RA1=RA2, and, preferably
equal to or lower than half the radius RA1 and RA2 of the first and
second drum, respectively, i.e. d1, d2.ltoreq.0.5.times.RA1=RA2.
Further, a minimum distance between a tip of a pin 66 and the outer
part 70 of the tearing roll 27 is preferably 1 cm.
[0049] As can be seen in FIG. 6, the radius RA3 of the tearing roll
27 is smaller than the radius RA1 of the first drum 24 and the
radius RA2 of the second drum 25.
[0050] As can be seen in FIG. 6, the tearing roll 27 is provided
with cutting elements 70 shaped as protruding knifes. Other
conceivable cutting elements are shaped as cutting discs 79
arranged on the tearing roll 77 shown in FIG. 7. A tearing roll
with cutting elements is efficient for cutting, for example, annual
plants. Such a tearing roll can also be operated at a higher
speed.
[0051] According to embodiments of the present invention, a
rotational speed of the tearing roll 27 is controlled by a motor 28
having a variable speed.
[0052] In embodiments of the present invention, the rotational
speed of the tearing roll 27 can be varied independently of a
rotational speed of the first and second drum 24, 25.
[0053] In embodiments of the present invention, the feeding
arrangement 20 is arranged to feed material to a plug screw feeder
30 in a feeding system 50, see FIG. 3. The plug screw feeder 30 and
the feeding arrangement 20 are preferably arranged perpendicular to
each other, i.e. the rotational axis of the plug screw is
perpendicular to a feeding direction of the feeding arrangement
20.
[0054] The plug screw feeder 30 is arranged to rotate at a variable
speed, wherein the speed of the plug screw feeder operates
independently of the drums 24, 25 and the tearing roll 27.
[0055] In embodiments of the present invention, the feeding
arrangement 20 is a so called pin drum feeder. The drums 24, 25 are
provided with protruding pins, for example cylindrical pins, for
transporting the material in a controlled manner. The pin drum
feeder is considered to be the "gas pedal" of the system,
controlling the production capacity. The pin drum feeder ensures
that an adequate amount of material is supplied to the plug screw
feeder.
[0056] With reference to FIG. 3, a feeding system according to the
present invention will be described. The system 50 comprises a
feeding arrangement 20 as described above with reference to FIG.
2.
[0057] An outlet opening 23 of the feeding arrangement 20 is
coupled to a force-feeding screw 50, in this embodiment a
plug-screw feeder, to feed biomass material to the plug-screw
feeder 30. The plug-screw feeder 30 transports the material to the
treatment process by the rotation of the plug screw 32. The plug
screw 32 is arranged in an elongated and cylindrical housing
31.
[0058] In this embodiment of the present invention, the feeding
arrangement is a pin drum feeder 20. The pin drum feeder is
arranged to provide a predetermined rate of material flow, i.e. the
production flow, which is achieved by co-operation between the
first and second drum 24, 25 and the grinding or tearing roll 27.
The rotational speed of the plug screw 32 is then set in relation
to the predetermined rate of material flow in order to achieve a
predetermined density increase of the material in the plug screw
feeder 30. If the production flow is increased, the rotational
speed of the plug screw 32 has to be increased to maintain the same
density in the plug screw feeder 30. If the rotational speed of the
plug screw 32 is maintained while the production flow increases,
the density will increase. By increasing the material density in
the plug screw feeder an essentially gas- and fluid-tight plug flow
of the annular material is created through the plug screw feeder
30.
[0059] As discussed above, the drums 24, 25 are provided with
protruding pins 66, for example cylindrical pins, for transporting
the material in a controlled manner. The pin drum feeder is
considered to be the "gas pedal" of the system, controlling the
production capacity. The pin drum feeder ensures that an adequate
amount of material is supplied to the plug screw feeder.
[0060] According to embodiments of the present invention, a
rotational speed of the tearing roll 27 is controlled by a motor 28
having a variable speed.
[0061] In embodiments of the present invention, the rotational
speed of the tearing roll 27 can be varied independently of a
rotational speed of the first and second drum 24, 25.
[0062] With reference to FIGS. 4 and 5 further embodiments of the
present invention will be described. The feeding arrangement 40 for
feeding biomass material to a treatment process, e.g. a
pre-hydrolysis process, comprises a transportation belt or conveyer
belt 41 having a receiving end 42 for receiving the biomass
material and a discharge end 43 for discharging the biomass
material. The conveyer belt 41 is controlled by a motor 46 having a
variable speed to provide a smooth and continuous flow of material.
In embodiments of the present invention, the feeding arrangement 40
is arranged to feed material to a plug screw feeder 61 in a feeding
system 60 arranged downstream the conveyer belt 41, see FIGS. 4 and
5. The plug screw feeder 61 and the feeding arrangement 40 may be
arranged perpendicular to each other, i.e. the rotational axis of
the plug screw 61 is perpendicular to a feeding direction F of the
feeding arrangement 40. The plug screw feeder 61 is arranged to
rotate at a variable speed, wherein the speed of the plug screw
feeder operates independently of the conveyer belt 41.
[0063] In an embodiment of the present invention illustrated in
FIG. 4, a grinding or tearing roll 47 is arranged at the discharge
end 43 of the conveyer belt 41 to tear off parts of biomass
material being discharged from the conveyer belt 41. The tearing
roll 47 is controlled by a motor 48 having a variable speed,
wherein a rotation of the tearing roll 47 is variable independently
of the conveying speed of the conveyer belt 41.
[0064] In embodiments of the present invention, an outer part of
the tearing roll 47 is arranged at predetermined distance d3 from
the discharge end 43 of the conveyer belt 41. In embodiments, the
distance d3 is within a range relative the thickness or height of
the layer or mat of biomass material transported on the conveyor
belt 41. In embodiments, the range is between 0.5.times. the height
of the layer (e.g. an average thickness of the layer) of the
transported material and 1.5.times. the height of the layer (e.g.
an average thickness of the layer) transported material, or at
least 50 mm.
[0065] In another embodiment of the present invention illustrated
in FIG. 5, a first tearing roll 47a is arranged at the discharge
end 42 of the conveyer belt 41 to tear off parts of biomass
material being discharged from the conveyer belt 41 to achieve a
smooth stream of material. A second tearing roll 47b is arranged
above a transportation side of the conveyer belt 41 to provide an
even distribution of the biomass material on the conveyer belt
41.
[0066] The tearing rolls 47a and 47b are controlled by a motor 48
having a variable speed, wherein a rotation of the tearing 48 is
variable independently of the conveying speed of the conveyer belt
41.
[0067] In embodiments of the present invention, the first tearing
roll 47a is arranged at a first predetermined distance d3 from the
discharge end 43 of the conveyer belt 41. In embodiments, the
distance d3 is within a range relative the thickness or height of
the layer or mat of biomass material transported on the conveyor
belt 41. In embodiments, the range is between 0.5.times. the height
of the layer (e.g. an average thickness of the layer) of the
transported material-1.5.times. the height of the layer (e.g. an
average thickness of the layer) transported material, or at least
50 mm.
[0068] The second tearing roll 47b is arranged at a second
predetermined distance d4 from the conveyer belt 41 within a range
relative the thickness or height of the layer or mat of biomass
material transported on the conveyor belt 41. In embodiments, the
range is between 0.5.times. the height of the layer (e.g. an
average thickness of the layer) of the transported
material-1.5.times. the height of the layer (e.g. an average
thickness of the layer) transported material, or at least 50
mm.
[0069] The tearing rolls 47a, 47b may be designed as the tearing
roll illustrated in FIG. 6 and as can be seen in FIG. 6, the
tearing roll 27 is provided with cutting elements shaped as
protruding knifes. Other conceivable cutting elements are shaped as
cutting discs 79 as shown in FIG. 7.
[0070] With reference to FIGS. 8a and 8b, another embodiment of a
tearing roll according to the present invention will be discussed.
The tearing roll 87 is provided with protruding pins or spikes 89.
The invention shall not be considered limited to the embodiments
illustrated, but can be modified and altered in many ways by one
skilled in the art, without departing from the scope of the
appended claims.
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