Note: Descriptions are shown in the official language in which they were submitted.
PULVERIZER SYSTEM
Field of the Invention
[0001] The present invention relates to a pulverizer also known as a vertical
grinding mill which are
provided with a rotating shaft with a plurality of arms spinning thereabout
which generate a series of air
currents inside of a cylinder to pulverize, separate, aerate, and/or
homogenize material.
Background of the Invention
100021 Solid materials such as garbage, rubbish or other solid materials have
been collected by trucks and
transported for disposal for many years.
[0003] Burkett developed a centrifugal mill sometime around in the mid-1970s
and ended up with U.S.
Patent No. 3,987,970 and others. The applicant's predecessor-in-interest filed
Canadian Patent
Application Nos. 2,125,797 and 2,147,666 for use with various equipment and
methods for pulverizing
rock and remediating soil utilizing an improved pulverizer configuration.
[0004] Still others have commercialized an embodiment of the Burkett mill and
are trying to sell that
design in the marketplace today. However, when attempting to build a Burkett
mill with improvements,
the applicant discovered there were components of that basic design which
could be improved.
Summary of the Invention
[0005] It is the present object of many embodiments of the present invention
to provide an improved
vertical gyroscopic mill or pulverizer having advanced capabilities.
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[0006] It is another object of many embodiments of the present invention to
provide an
improved pulverizer having improved safety features.
[0007] It is another object of many embodiments of the present invention to
provide an
improved pulverizer having improved performance characteristics.
[0008] It is another object of many embodiments of the present invention to
provide improved
efficiency, possibly coupled to increased output and/or reduced down time.
[0009] It is another object of many embodiments to provide improved
performance for a
pulverizer by having adjustable air flow characteristics other than adjustable
shaft rotation speed
alone.
[00010] It is another object of many embodiments of the present invention to
provide an
improved shaft wrapping removal system.
[00011] It is another object of many embodiments of the present invention to
provide an
improved dust collection system.
[00012] Accordingly, in accordance with a presently preferred embodiment of
the present
invention, a pulverizer or vertical gyroscopic mill can be combined with a
conveyor system for
(a) feeding the pulverizer and/or (b) likely for removing discharge. The speed
of the
conveyor(s), particularly the feed conveyor, as well as the speed of the
rotation of the pulverizer
are preferably controlled by a processor possibly in an interrelated manner.
Furthermore, the
shaft may be driven by a variable frequency drive motor or other variable
speed motor to allow
for the processor to control aspects of the speed of the motor. Feedback loops
are helpful for
some operations of the processor as well, such as to maintain constant power
levels and/or feed
flows.
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[00013] A system may control the rate of infeed to at least assist in
controlling the process for at
least some embodiments.
[00014] A system may control the speed of the rotor for some embodiments such
as to maintain
a specified power level and/or for other objectives.
[00015] Additionally, for at least some embodiments, it may be that the speed
of the motor and
the speed of the conveyor can be linked together so that if the speed of the
shaft rotation of the
pulverizer is sensed to decrease, then the speed of the conveyor can be
correspondingly
decreased as well, such as a proportional amount, possibly as compared to
overall speeds,
amount of decrease or other amounts. Furthermore, if a high resistant object
is encountered with
an arm and the shaft speed slows down a significant amount, it may be that the
processor can
direct the ramping back up of the shaft speed after a sudden slow down
possibly as well as a
corresponding slowing down and then speeding up of the conveyor.
[00016] For some embodiments, a vibration sensor can be used to detect when
the shaft and/or
other components of the pulverizer are vibrating too much to then direct a
potential shut down
sub-routine to determine the cause of the vibration. The vibration could be
caused by
unbalanced loading, which could be addressed by first slowing, and then
possibly stopping the
feed conveyor. The shaft may be slowed slightly, or significantly to see if
the vibration clears.
Finally, if none of the above slows the vibration issue, the shaft may be
stopped.
[00017] Additionally, software of at least some embodiments can detect
wrapping by sensing an
increase in amperage possibly coupled with other effects such as no
significant increase or
decrease in output or throughput and/or other effects. Once detecting a
wrapping step, the
processor may stop the shaft. After stopping the feed conveyor, the processor
may direct a
reverse direction of the shaft for a predetermined speed and/or time (or
alternating directions) to
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allow attempt to dislodge material from wrapped arms. Similarly, if resistance
is deemed too low, the
processor can speed up certain factors.
[00018] Additionally, in an effort to prevent shaft wrapping which can often
occur with the top of the
pulverizer above the uppermost arm segments, at least one cutting mechanism
can be provided in an
effort to attempt to cut material which may otherwise wrap towards an upper
end of the shaft.
[00019] A door opening prevention separator lock for many embodiments can be
provided to prevent an
access door of the pulverizer from being opened while in operation, or even
during spin down after shutting
off the pulverizer. Once the shaft is stopped, the interlock may then allow
the access door to open.
[00020] Additionally, software can be used to maintain the environment of
pressure below ambient such
as at some vacuum value possibly in combination with a dust depression system
at an outlet of the
pulverizer possibly with a separator lock option at the outlet so as to
prevent, or at least significantly
reduce dust in the environment to reduce dust about the pulverizer during
operation.
[00021] Still these and/or other features may be provided with still other
embodiments.
According to one aspect, there is provided a pulverizer comprising: a top
having an inlet; a bottom having
an outlet; a conveyor for feeding material into the inlet; a drum located
between the top and the bottom; a rotating
shaft extending vertically within the drum between the top and the bottom, the
rotating shaft having radially
extending arms for reducing the size of material fed into the inlet and
producing a size reduced material which
is discharged through the outlet; and a processor operatively connected to at
least one of the shaft and the
conveyor for controlling a speed of the at least one of the shaft and the
conveyor based at least partially on
input of at least one sensor operatively connected to the processor, the
processor being configured for
temporarily reversing rotation of the shaft upon detection by at least one of
the at least one sensor of a
wrapping of material around at least one of the arms and the shaft.
According to one aspect, there is also provided a method for pulverizing a
material, the method
comprising: using a conveyor, feeding the material into an inlet of a
pulverizer, the pulverizer having a top
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Date recue/Date Received 2020-08-28
comprising the inlet, a bottom and a drum located between the top and the
bottom; rotating a rotating shaft of the
pulverizer within the drum, the rotating shaft extending vertically within the
drum between the top and the
bottom, the rotating shaft having radially extending arms reducing the size of
the material provided at the inlet
and discharged at the bottom; controlling the speed of at least one of the
conveyor and the rotating shaft based
on an input received from at least one sensor, the controlling the speed of at
least one of the conveyor and the
rotating shaft comprising: upon detecting wrapping of material about at least
one of the arms and the shaft,
reversing direction of rotation of the shaft.
Brief Description of the Drawings
[00022] The particular features and advantages of the invention as well as
other objects will become
apparent from the following description taken in connection with the
accompanying drawings in which:
Figure 1 is a schematic representation of a pulverizer system of a presently
preferred embodiment
of the present invention;
Figure 2 is a detailed cross sectional view of the dust collection intake
shown in Figure 1;
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Figure 3 is an internal view of detail B shown in Figure 1;
Figure 4 is a schematic view of a portion of the present invention; and
Figure 5 is a schematic view of a portion of the present invention.
Detailed Description of the Preferred Embodiments
[00023] Figure 1 shows essentially a schematic representation of the
pulverizer system 100 in
the form of a feed conveyor 12, feeding to an inlet 14 of a pulverizer 16.
Once material is
pulverized, it exits out at 18 where optional air lock 20 may assist in
discharging ground material
onto conveyor 22 or alternatively, it may be that material directed from
outlet is deposited
directly onto conveyor 22 without optional air lock 20, illustrated.
[00024] Dust collector system 24 is useful for some, if not many embodiments,
to remove dust
and will be described in further detail with reference back to Figures 1 and
4, possibly under the
direction of processor 26. Processor 26 can control many aspects of the system
100 in the
pulverizer 16 as will be discussed in further detail below.
[00025] The pulverizer 16 is preferably equipped with a variable speed motor
28 such as a
variable frequency drive motor which can allow for the processor 26 to assist
in controlling the
speed of the motor 28. Additionally, the processor 26 may also control the
speed of feed of the
conveyor 12.
[00026] For instance, by having a processor 26 control operation of both the
feed (i.e., the
amount of fed material) into inlet 14 by controlling the speed of the conveyor
12, possibly in
combination with sensors such as sensor 30 directed at conveyor 12 which can
sense the input of
material into inlet 14. The amount of feed directed into the pulverizer 16
through inlet 14 can be
monitored and/or controlled possibly in combination with the speed of rotation
of the shaft 32 in
an effort to address a variety of different operating conditions.
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[00027] For instance, during normal operations, if a particular hard grind
product is directed into
inlet 14, the shaft 32 may reduce rotational speed about rotation axis 34. In
order to ramp back
up to optimal, it may be that the processor 26 has a ramp up speed routine as
provided to the
motor 28 so that instead of attempting to instantaneously maintain speed,
either a predetermined
ramp up routine is selected such as a linear increase or non-linear curve back
to speed or possibly
having a predetermined intermediate speeds back up to an optimum speed is
achieved by the
processor 26 running software as provided therewith. Conveyor 12 may follow a
similar or
dissimilar routine.
[00028] Another aspect of the pulverizing system 100 is that the input as
provided through inlet
14 can be varied, possibly together with the speed of rotation of the shaft 32
by the motor 28
under certain operating conditions as well. Depending on the particular type
of input in inlet 14,
a different rate of feed of the conveyor 12 can be selected relative to the
speed of the rotation of
the shaft 32 about axis 34. Other factors may be addressed with processor 26
to attempt to
improve efficiency as well.
[00029] Depending on the particular input at issue, it may be that the speed
of rotation of the
shaft 32 can be selected relative to the speed of the conveyor 12 and/or vice
versa and/or the
amount of input in inlet 14 possibly in combination with the sensor 30 or
other way to measure
input into inlet 14. Another feature which can be controlled with the
pulverizer 16 is its internal
pressure which may be assisted in being controlled by a dust collection system
24 or other
system. By directing the pressure inside pulverizer 16 to possibly be below
atmospheric pressure
such as by using the dust control system 24, the relative size of particulate
leaving the outlet 18
can be reduced. Under certain circumstances, the particulate size as deposited
from the outlet
conveyor 22 may be more preferably controlled by addressing a pressure in the
pulverizer 16,
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such as with processor 26. Of course, outlet conveyor 22 could have material
redirected back
into inlet 14 under certain conditions to regrind material and/or could be
controlled by processor
26 as well. Dust collection system 24 could be useful to prevent the area
around the pulverizer
16 from being a dusty mess. Dust collecting system 24 may also collect useful
products from the
grinding operation.
[00030] Also, when the shaft 32 is ramping back up to speed as directed by the
processor but the
processor 26 may also simultaneously slow down the conveyor 12 and/or maintain
a
predetermined speed during the ramp up process so as to not overload the input
in the inlet 14 of
= the pulverizer 16.
[00031] Also, the processor 26 may perform other functions like direct the
flow of input into
inlet 14 in order to attempt to maintain a relatively stable power level based
on consumption of
energy of either the overall system and/or by the motor 28.
[00032] For instance, when encountering an increased power consumption by the
motor 28, it
may be that the input is slowed such as by slowing the conveyor 12 or other
step. Furthermore if
power consumption is not significant enough as consumed the motor 28, it may
be that the
conveyor 12 can be sped up by the processor 26.
[00033] In addition to providing instructions to control both the speed of the
motor 28, to thus
control the rotational speed of the shaft 32, as well as the speed of the
conveyor 12, it may be
that there is a feed back loop provided back to the processor 26 for various
effects. For instance,
it has been discovered that through shelf height optimization, as will be
described in further
detail below, it may be that a higher throughput (i.e., a higher rate of flow
from both into the
inlet 14 and outlet 18) can be achieved with a lower power consumption of the
motor 28 based
on the shelf 36 being provided at a selected height provided through way of
adjustment. A 20%
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higher throughput has been achieved for some feed streams by selecting the
specific height of the
shelf 36 for some embodiments. By changing the shelf 36 height, the vortices
flow in at least the
middle section 38 can be varied to effectively change the configuration of
those vortices, at least
clevationally. Furthermore, it may be that the change in shelf height 36 it
may be imparted to the
other shelves namely 40 and/or 42 and/or other shelves which could be changed
in height as
well. Additionally, the relative shape of deflectors or shelves 36,40,42 such
as deflector 44 in a
similar or dissimilar manner as the shelf 36 is changed in height as will be
explained in further
detail below.
[00034] By providing a feedback route such as with an accelerometer 46
connected to the shaft
32 as well as a variable speed motor 28 such as could be driven by a variable
frequency drive
system or otherwise, a way of not only providing a desired signal to the motor
28 for a desired
speed of the shaft 32 can be provided, but also the speed itself can be sensed
with sensor 46 and
provided to processor 26.
[00035] Other sensors can be utilized with this system which are not presently
utilized.
Specifically, a door locking interlock and/or sensor 48 can be provided for
use by processor 26
or other device so that access door 50 so that the door 50 may not be opened
as illustrated in
Figure 1, unless the shaft 32 is stationary. This feature can prevent the door
50 from being
unlocked such as with locking system 52 as might be restrained from opening by
lock 48 under
certain conditions. Additionally, a vibration sensor 54 may be provided so as
to be able to sense
vibration of the shaft 32 and/or other portions of the pulverizer 16. A
vibration protocol may be
employed by the processor 26 so that upon reaching a first predetermined
amount of vibration,
certain steps are performed such as by first slowing down the motor 28 and/or
conveyor 12 to see
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if the vibration diminishes, and if not, then possibly securing the conveyor
12 and then end the
motor 28. A second predetermined amount could result in shutdown of the motor
28 directly.
[00036] If the vibration sensor 54 detects the shaft 32 as sensing too much
vibration, then it
could indicate that a pin is sheared, an arm pad has been damaged, or other
complicating factor
internal to the pulverizer 16 which could then be somewhat of a self-
diagnosing pulverizer 16. If
a second predetermined amount of vibration is sensed, it may be that the motor
28 is secured
immediately as opposed to going through a slowing step to discourage internal
damage in the
pulverizer 16..
[00037] Of course, the processor 26 could also control the air lock 20, if
utilized, as well as the
speed of being able to move material onto conveyor 22 and/or the speed of the
conveyor 22.
Processor 26 may also control the air flow through the dust controller system
24 if utilized and/or
could assist in maintaining a desired pressure such as a vacuum or other
pressure internal to the
pulverizer 16 and/or assist in maximizing efficiency of the fan 56 of the dust
collector 24 for
efficiency or other purposes such as removing dust of a given particulate
size.
[00038] Fan 56 might be a 30 horsepower motor capable of drawing 1000 cubic
feet per minute
or have other specifications for various other dust collector systems 24. It
turns out that for
many processes, the dust collected in various bags 58 can prove to be quite
valuable such as
when grounding electronics, it may be that gold dust can be retrieved from the
bags 56,58. Other
waste may have other valuable components which may be recovered from waste
bags 58.
Plenum 60 could be made of the appropriate gauge of material to be able to
withstand the suction
forces as provided by fan 56 and it may be that the amount of suction can be
varied such as not
only with the speed of the fan 56 but also with the size of the opening 62 as
will be discussed in
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further detail with reference to Figure 4 below either of which could be
controlled by processor
26 or otherwise.
[00039] The software used by the processor 26 could detect wrapping such as by
sensing an
increase of amperage without noticing any increase in output 18 and/or input
14 and/or possibly
also observing that the amperage is slowly increasing by the motor 28 as it
being required by the
motor 28. Vibration sensed by the vibration sensor 54 may also contribute to
the ability to detect
wrapping.
[00040] If wrapping is occurring on the arms, such as any of arms 64,66,68,
then a routine can
be employed to attempt to shed the wrap material from the arms. Specifically,
the shaft 32 could
be stopped as shown by processor and possibly even the arms 64-68 could then
be reversed in
direction to attempt to free the arms 64-68 from the wrap material. It may be
that a series of
spinning in the first direction about the axis and then reversing direction
about the axis 34 may
be employed in order to attempt to remove such material. Should this step fail
to work, then it
may be that the door 50 might need to be opened or the shafts 32 stopped to
remove any excess
wrapped material.
[00041] Additionally, if wrapping up on the shaft 32 such as at any of the
hubs or even towards
the upper portion 74 of pulverizer 16, a shaft wrapping removal system could
be employed
similar to the one shown in Figure 5. Specifically, a spacing rib 70 is shown
which can assist in
pushing material up and away from the shaft 32 or alternatively along a
shedding cone 72 or
such as one outwardly extending from shaft 32 which might otherwise direct
material up towards
the spacing rib 70 and/or upper portion 74 of the pulverizer 16. As it travels
up the spacing rib
70, it may encounter a first blade 76 which preferably cuts through any
material as it passes
through or certainly once a predetermined thickness illustrated as thickness
78 is encountered, a
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second blade or stop 80 can contact the material to either assist in pushing
that wrapped material
against the first blade 76 and/or cut wrap material with the second blade or
stop 80.
Accordingly, the most that could be possibly wrapped would likely be of a
thickness 78 between
the first blade 76 and the second blade or stop 80. Accordingly, as the
material attempts to wrap,
the material is removed and cut by the blades 76 and/or 80. VHS tapes
particularly have a
tendency to come unraveled and perform as well as do other certain feed stocks
possibly
including wires, labels, plastic and/or other materials.
[00042] Thc cone 72 when utilized works as a shedding cone to assist the
direction of such
materials up into the cutting area of the shaft wrapping removal device
illustrated. An access
plate 82 may be useful to be able to open the access either the first or
second cutting blade 76,80
possibly from outside the pulverizer 16 for adjustment and/or replacement. The
cone 72 can be a
shedding cone and can further assist in the ability to direct material up to
the cutting surfaces of
the blade 76 and/or 80. The cone 72 has a larger diameter at a bottom of the
cone 72 and
increases in diameter before going downwardly.
[00043] Accordingly, some embodiments provide a pulverizer 16 comprising a top
1 with an
inlet 14, and a conveyor 12 feeding an inlet 14 at the top, a bottom 3, a drum
5 located between
the top 1 to the bottom 3, a rotating shaft 32 having radially extending arms
64,66,68 creating
flow currents within the pulverizer thereby reducing the size of product input
at the inlet 14 and
discharged at the bottom 3 at exit 18, and a processor 26 directing the speed
of at least one, if not
both, of (a) the shaft 32 and (b) the conveyor 12 based at least partially on
input of sensors 30
and/or 46, and/or others. A variable speed motor 28, such as a variable
frequency drive motor or
other motor, directed by the processor 26 may drive the shaft. The processor
26 may be used for
other functions such as at least assist in controlling pressure in the drum of
the pressurizer 16
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such as by controlling a dust collection system 24, possibly having a variable
vacuum controlled
by the processor 26. Another processor function may be directing the rotation
of the shaft 32 in
one of a forward and a reverse direction based on detected wrapping of debris
about one of the
shaft and the arms 64,66,68.
[00044] Some embodiments may provide a shaft speed sensor 46 and further
comprising a feed
back loop communicating shaft speed to the processor 26. These or other
embodiments may
provide a door interlock 48 whereby the processor 26 prevents opening an
access door 50 to the
drum when the shaft 32 is rotating. These or other embodiments may provide a
vibration sensor
such as 46 with the processor 26 directing slowing down the pulverizer 16 if
vibration exceeds a
first predetermined threshold, and/or stopping the pulverizer 16 if vibration
exceeds a second
predetermined threshold.
[00045] Some embodiments .may provide a wrap detection algorithm used by the
processor 26
whereby wrapping of material about the arms 64,66,68 is detected by
performance of the
pulverizer 16. Some algorithms may employ sensing at least one of an increase
in amperage
required by the motor 28, slowing down of the shaft and increased vibration
such as may be
sensed by sensor 46 and/or another sensor. If wrapping about the shaft 32 is
detected, some
embodiments may provide, the pulverizer 16 reverses direction of rotation of
the shaft 32, at
least briefly in an effort to dislodge wrapped material on the arms 64-68.
Spacing ribs 70 and/or
a shedding cone 72 located in the drum 5 toward the inlet 16 at the top 1, or
upper portion 74 of
the pulverizer 16, may be useful to discourage wrapping for many embodiments
as well. With
the shedding cone 72, for at least some embodiments, at least one blade 76 or
80 near a top of the
cone 72 may assist in cutting debris which might otherwise wrap about the
shaft 32. Still other
embodiments may have some, or all of these features, as well as, or even
others.
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[00046] Numerous alterations of the structure herein disclosed will suggest
themselves to those
skilled in the art. However, it is to be understood that the present
disclosure relates to the
preferred embodiment of the invention which is for purposes of illustration
only and not to be
construed as a limitation of the invention. All such modifications which do
not depart from the
spirit of the invention are intended to be included within the scope of the
appended claims.
[00047] Having thus set forth the nature of the invention, what is claimed
herein is:
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