Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR PULVERIZING AND EXTRACTING MOISTURE
Field of the Invention
The present invention relates to techniques for processing materials to
pulverize
and extract moisture.
Background of the Invention
Numerous industries require the labor intensive task of reducing materials to
smaller particles and even to a fine powder. For example, the utility industry
requires
coal to be reduced from nuggets to powder before being burned in power
generation
furnaces. Limestone, chalk and many other minerals must also, for most uses,
be
reduced to powder form. Breaking up solids and grinding it into powder is a
mechanically demanding process. Ball mills, hammer mills, and other mechanical
structures impact on, and crush, the pieces of material. These systems,
although
functional, are inefficient and relatively slow in processing.
Numerous industries further require moisture extraction from a wide range of
materials. Food processing, sewage waste treatment, crop harvesting, mining,
and
many other industries require moisture extraction. In some industries
materials are
discarded because moisture extraction cannot be performed efficiently. These
same
materials, if they could be efficiently dried, would otherwise provide a
commercial
benefit. In other industries, such as waste treatment and processing, water
extraction is
an ongoing concern and tremendous demand exists for improved methods. Although
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several techniques exist for dehydrating materials, there is an increasing
need for
improved moisture extraction efficiency.
Thus, it would be an advancement in the art to provide more efficient
processes
for pulverizing materials and extracting moisture from materials. Such
techniques are
disclosed and claimed herein.
Brief Description of the Drawings
A more particular description of the invention briefly described above will be
rendered by reference to the appended drawings. Understanding that these
drawings
only provide information concerning typical embodiments of the invention and
are not
therefore to be considered limiting of its scope, the invention wilt be
described and
explained with additional specificity and detail through the use of the
accompanying
drawings, in which:
Figure 1 is a side view illustrating one embodiment of a pulverizing system of
the
present invention;
Figure 2 is a plan view illustrating the pulverizing system of Figure 1;
Figure 3 is a cross-sectional side view illustrating a venturi of a
pulverizing
system as the venturi receives material;
Figure 4 is a side view illustrating an alternative embodiment of a
pulverizing
system of the present invention;
Figure 5 is a plan view illustrating a plan view of the pulverizing system of
Figure
4;
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Figure 6 is a perspective view illustrating an air generator housing and
outlet
restrictors;
Figure 7 is a cross-sectional view of one embodiment of an air generator
housing;
Figure 8 is cross-sectional view of a venturi and a throat resizer;
Figure 9 is a block diagram illustrating the components of an alternative
embodiment of a pulverizing system;
Figure 10 is a block diagram illustrating an alternative embodiment of a
pulverizing system of the present invention;
Figure 11 is a perspective view of one embodiment of an airflow generator
suitable for use with a system of the present invention;
Figure 12 is a cross-sectional view of a portion of the airflow generator of
Figure
11;
Figure 13 is a plan view of an interior portion of the airflow generator of
Figure
11;
Figure 14A is a plan view of a trailing edge of a blade of the airflow
generator of
Figure 11;
Figure 14B is a plan view of an alternative embodiment of a trailing edge of a
blade of the airflow generator of Figure 11;
Figure 15A is a perspective view of a portion of the airflow generator of
Figure
11;
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Figure 15B is a perspective view of a portion of an alternative embodiment of
an
airflow generator of Figure 11;
Figure 16 is a side view of a blade of the airflow generator of Figure 11;
Figure 17 is a cross-sectional view of the blade of Figure 16;
Figure 18 is a perspective view of a portion of the airtlow generator of
Figure 11;
Figure 19 is a side view of an alternative embodiment of a pulverizing system
of
the present invention;
Figure 20 is a side view illustrating an alternative embodiment of a
pulverizing
system of the present invention;
Figure 21 is a side view illustrating an alternative embodiment of a
pulverizing
system of the present invention;
Figure 22 is a cross-sectional view an alternative embodiment of an air
generator
housing;
Figure 23 is a perspective view of an embodiment of a housing, axle, and
balancer;
Figure 24A is a diagram illustrating a position of compensating weights
relative to
a point of imbalance;
Figure 24B is another diagram illustrating a position of compensating weights
relative to a point of imbalance;
Figure 25A is another diagram illustrating a position of compensating weights
relative to a point of imbalance;
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Figure 25B is another diagram illustrating a position of compensating weights
relative to a point of imbalance;
Figure 26A is a perspective view of a balancer relative to a rotating mass;
Figure 26B is another perspective view of a balancer relative to a rotating
mass;
Figure 27 is a cross-sectional view of one embodiment of an internal balancer
disposed within an axle;
Figure 28 is a cross-sectional view of one embodiment of compensating weights
within the internal balancer of Figure 27;
Figure 29 is a perspective view of one embodiment of a ring balancer; and
Figure 30 is a cross-sectional view of one embodiment of compensating weights
within the ring balancer of Figure 29.
Detailed Description of Preferred Embodiments
Referring to Figures 1 and 2, a system 10 for pulverizing and extracting
moisture is shown that includes an inlet tube 12. The inlet tube 12 includes a
first end
14, communicating with free space and an opposing, second end 16 that couples
to a
venturi 18. Although reference is made herein to tubes and pipes, one of skill
in the art
will appreciate that all such elements may have circular, rectangular,
hexagonal, and
S
other cross-sectional shapes. Generally, circular cross-sections are desirable
to
facilitate fabrication and operation, but the invention is not limited to such
a specific
implementation.
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The inlet tube 12 provides some distance to the venturi 18 in which material
can
accelerate to the required velocity. A filter (not shown) may be placed to
cover the first
end 14 to prevent introduction of foreign particles into the system 10. The
inlet tube 12
further includes an elongated opening 20 on an upper part thereof to allow
communication with the open lower end of a hopper 22. The hopper 22 is open at
its
upper end 24 to receive materials. In an alternative embodiment, the system 10
does
not include a hopper 10 and material is simply inserted into the elongated
opening 20
through various known conventional methods.
The venturi 18 includes a converging portion 26 coupled to the inlet tube 12.
The
converging portion 26 progressively reduces in diameter from that of the inlet
tube 12 to
a diameter smaller than the inlet tube 12. The venturi 18 further includes a
throat 28
that maintains a consistent diameter and is smaller than the diameter of the
inlet tube
12. The venturi 18 further includes a diverging portion 30 that couples to the
throat 28
and progressively increases in diameter in the direction of airtlow. The
diverging portion
30 may be coupled to the throat 28 by casting, screw threads, or by other
known
methods. As illustrated, the converging portion 26 may be longer in
longitudinal length
than the diverging portion 30.
The venturi 18 is in communication with an airflow generator 32 that creates
an
airtlow flowing from the first end 14, through the inlet tube 12, through the
venturi 18,
and to the airtlow generator 32. The velocity of the generated airflow may
range from
350 mph to supersonic. The airflow velocity will be greater in the venturi 18
than in the
inlet tube 12. The airflow generator 32 may be embodied as a fan, impeller,
turbine, a
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hybrid of a turbine and fan, a pneumatic suction system, or other suitable
device for
generating a high speed airflow.
The airflow generator 32 is driven by a drive motor 34. The drive motor 34
couples to an axle 33 using known methods. The axle 33 engages the airflow
generator
32 to power rotation. The horse power of a drive motor 34 will vary
significantly, such
as from 15 hp to 1000 hp, and~depends on material to be treated, material flow
rate, and
airflow generator dimensions. Thus, this range is for illustrative purposes
only as the
system 10 can be scaled up or down. An upper scale system 10 may be used at a
municipal waste processing facility whereas a smaller scale system 10 may be
used to
process sewage waste on board an ocean vessel.
The airflow generator 32 includes a plurality of radially extending blades
that
rotate to generate a high speed airflow. The airflow generator 32 is disposed
within a
housing 35 that includes a housing outlet 36 that provides an exit to incoming
air. The
housing 35 couples with the venturi 18 and has a housing input aperture (not
shown)
that allows communication between the venturi 18 and the interior of the
housing 35.
The blades define radially extending flow passages through which air passes to
a
housing outlet 36 on its periphery to allow pulverized material to exit. One
embodiment
of an airflow generator 32 suitable for use with the present invention is
discussed in
further detail below in reference to Figures 11 to 18.
Referring to Figure 3, a diagram is shown illustrating operation of the
venturi 18
during a pulverization event. In operation, material 38 is introduced into the
inlet tube
12 through any number of conveyance methods. The material 38 may be a solid or
a
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semi-solid. The airflow generator 32 generates an air stream, ranging firom
350 mph to
supersonic, that flows through the inlet tube 12 and through the venturi 18.
In the
venturi 18, the airflow velocity substantially accelerates. The material 38 is
propelled by
the high speed airflow to the venturi 18. The material 38 is smaller in
diameter than the
interior diameter of the inlet tube 12 and a gap exists between the inner
surface of the
inlet tube 12 and the material 38.
As the material 38 enters the converging portion 26, the gap becomes narrower
and eventually the material 38 causes a substantial reduction in the area of
the
converging portion 26 through which air can flow. A recompression shock wave
40
trails rearwardly from the material and a bow shock wave 42 builds up ahead
ofi the
material 38. Where the converging portion 26 merges with the throat 28 there
is a
standing shock wave 44. The action of these shack waves 40, 42, 44 impacts the
material 38 and results in pulverization and moisture extraction from the
material. The
pulverized material 45 continues through the venturi 18 and exits into the
airflow
generator 32.
The material size reduction depends on the material to be pulverized and the
dimensions of the system 10. By increasing the velocity of the airflow,
pulverization and
particle size reduction increases with certain materials. Thus, the system 10
allows the
user to vary desired particle dimensions by varying the velocity of the
airflow.
The system 10 has particular application in pulverizing solid materials into a
fine
dust. The system 10 has further application in extracting moisture from semi-
solid
materials such as municipal waste, paper sludge, animal by-product waste,
fruit pulp,
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and so forth. The system 10 may be used in a wide range of commercial and
industrial
applications.
Referring to Figures 4 and 5, an alternative embodiment of a system 100 of the
present invention is shown for extracting moisture from materials. The system
100 may
include a blender 102 for blending materials in a preprocessing stage. Raw
material
may include polymers that tend to lump the material into granules. The
granules may
be oversized and, due to the polymers, resist breaking down into a desired
powder
form.
The presence of polymers is typical with municipal waste as polymers are
introduced during sewage treatment to bring the waste particles together.
Waste is
processed on a belt press resulting in a material that is mostly semi-solid.
In some
processes the material may be approximately 15 to 20 percent solid and the
remainder
moisture.
In the preprocessing stage, a drying enhancing agent is mixed with the raw
material to break down the polymers and the granulization of the material. Non-
polymerized products may be processed without the blending. Raw material is
introduced into the blender 102 that blends the material with a certain amount
of a
drying enhancing agent. The drying enhancing agent may be selected from a wide
range of enhancers such as attapulgite, coal, lime, and the like. The drying
enhancing
agent may also be a pulverized and dried form of the raw material. The blender
102
mixes the material with the drying enhancing agent to produce an appropriate
moisture
content and granular size.
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The raw material is transferred from the blender 102 to the hopper 22 in any
one
of a number of methods including use of a conveyance device 104 such as a belt
conveyor, screw conveyor, extruder, or other motorized devices. In the
illustrated
embodiment, the conveyance device 104 is an inclined track that relies on
gravity to
deliver raw material to the hopper 22. The conveyance device 104 is positioned
below
a flow control valve 106 located on the lower portion of the blender 102.
In an alternative embodiment, the hopper 22 may be eliminated and material is
delivered directly to the elongated opening 20 of the inlet tube 12. The
hopper 22 is
only one device that may be used to facilitate delivery of material to the
inlet tube 12.
Any number of other types of conveyance devices may be used as well as manual
delivery.
One or more sensors 108 may monitor the flow rate of material passing from the
blender 102 to the inlet tube 12. A sensor 108 is in communication with a
central
processor 110 to regulate the flow rate. The sensor 108 may be disposed
proximate to
the conveyance device 104, proximate to the hopper 22, within the hopper 22,
or even
between the hopper 22 and the elongated opening 20 to monitor the material
flow rate.
The central processor 110 is in communication with the flow control valve 106
to
increase or decrease the flow rate as needed. Alternative methods for
monitoring and
controlling the flow rate may also be used including visual inspection and
manual
adjustment of the flow control valve 106. .
The hopper 22 receives the material and delivers the material to the elongated
opening 20 of the inlet tube 12. The elongated opening 20 may be equal to or
less than
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4" wide and 5" long to maintain an acceptable feed flow for certain
applications. The
length of inlet tube 12 from the elongated opening 20 to the venturi 18 may
range from
24" (610 mm) to 72" (1830 mm) or more and depends on material to be processed
and
the flow rate. One of skill in the art will appreciate that the dimension are
for illustrated
purposes only as the system 10 is scalable.
The airflow pulls the material from the inlet tube 12 through the venturi 18.
In the
illustrated embodiment, the first end 14 is configured as a flange to converge
from a
diameter greater than the inlet tube 12 to the diameter of the inlet tube. The
flange
configured first end 14 increases airflow volume into the inlet tube 12.
Certain embodiments have the throat diameter of the venturi 18 ranging from
approximately 1.5 " (38 mm) to approximately 6" (152 mm). The throat diameter
is
scalable based on material flow volume and may exceed the previously stated
range.
The throat diameter of the venturi 18 and the inlet tube 12 are directly
proportional. In
one embodiment, the throat diameter is 2.75" and operates with an inlet tube
diameter
of 5.5" (139.33 mm). In an alternative embodiment, the throat diameter may be
2.25"
(57 mm) and operates properly with an inlet tube diameter of 4.50" (114 mm).
Thus, a 2
to 1 ratio ensures that raw feed material is captured in the incoming airtlow.
In the illustrated embodiment, the diverging section 30 couples to the housing
35
and communicates directly with the housing 35. The final diameter of the
diverging
section 30 is not necessarily the same as the inlet tube 12. In an alternative
embodiment, the diverging section 30 may couple to an intermediary component,
such
as a cylinder, tube, or pipe, prior to coupling with the housing 35.
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One or more flow valves 111 may be disposed on the diverging portion 30 and
provide additional air volume into the interior of the housing 35 and the
airflow generator
32. The additional air volume increases the airflow generator 32 performance.
In one
embodiment, two flow valves 111 are disposed on the diverging portion 30. The
system
100 may be operated with the flow valves 111 partially or completely opened.
If
material begins to obstruct the venturi 18, the flow valves 111 may be closed.
This
results in more airflow through the venturi 18 to provide additional force and
drive
material through the venturi 18 and the airflow generator 32. The flow valves
111 are
adjustable and are shown in electrical communication with the central
processor 110 for
control. Although manual operation of the flow valves 111 is within the scope
of the
invention, computer automation greatly facilitates the process.
The venturi 18 provides a point of impact between higher velocity shock waves
and lower velocity shock waves. The shockwaves provide a pulverization and
moisture
extraction event within the venturi 1.8. In operation, there are no visible
signs of
moisture on the interior of the venturi 18 or in the housing outlet 36. The
amount of
moisture removed is substantial although a residual amount may remain. The
pulverization event further reduces the size of materials. It has been
experienced that
certain materials having a diameter of 2" (50 mm) entering the venturi 18 are
reduced to
a fine powder with a diameter of 20 um in one pulverization event. Size
reduction
depends on the material being processed and the number of pulverization
events.
Separating water from the material has numerous applications such as material
dehydration and greatly reducing the number of pathogens.
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The present invention has particular application in processing municipal
waste.
The preprocessing step of blending a drying enhancing agent provides a waste
material
that is readily processed by the system 100. It is believed that the
pulverizing and
moisture extraction process greatly reduces the amount of illness causing
pathogens in
the waste material by rupturing their cell wall. A second source of pathogen
reduction is
moisture extraction which reduces the pathogens. Analytical data from treating
municipal waste shows that the present invention eliminates the majority of
total
colifrom, faecal coliform, escherichia coli, and other pathogens.
The present invention has specific application in extracting moisture from
fruit
and vegetable products. In one application, the system 100 may be used to
dehydrate
fruit and vegetable products such as apples, oranges, carrots, nectarines,
peaches,
melons, tomatoes, and so forth. Extracted moisture, which is relatively
sanitary, may be
condensed and recaptured to provide a pure juice product.
In another application, the invention may be used to pulverize and extract
water
from certain agricultural products such as banana stalk, palm trees, sugar
canes,
rhubarb, and so forth. In pulverizing banana stalk fibers, the fibers are
separated and
moisture is extracted. Commercial applications exist in taking agricultural
products from
their nafiural state to a dehydrated state.
The material, moisture, and air stream proceed through the airflow generator
32
and exit through the housing outlet 36. The housing outlet 36 is coupled to an
exhaust
pipe 112 which delivers the material to a cyclone 114 for material and air
separation.
The diameter of the exhaust pipe 112 may range from approximately 4" (100 mm)
to 7"
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(177 mm). It may be necessary to exceed this given range for certain materials
such as
attapulgite or coal where a 8" (203 mm) exhaust pipe 112 is appropriate. The
exhaust
pipe 112 may have a cross-section of various shapes, i.e. rectangular,
octagonal, etc.
and may have various diameters.
The exhaust pipe 112 may have a length of approximately 12 feet to 16 feet.
The diameter size of the exhaust pipe 112 impacts the amount of drying that
further
occurs. High air volume is required for further drying of materials. In the
exhaust pipe
112, the faster moving air in the exhaust pipe 112 passes the material and
removes
moisture remaining on the material. The air and vapor travel to a cyclone 114
where air
and vapor are separated from the solid material.
A pulverization event generates heat that assists in drying the material. In
addition to pulverization, rotation of the airflow generator 32 generates
heat. The
dimensions between the housing 35 and the airtlow generator 32 are such that
during
rotation the friction generates heat. The heat exits through the housing
outlet 36 and
exhaust pipe 112 and further dehydrates the material as the material travels
to the
cyclone 114. The generated heat may also be sufficient to partially sterilize
the material
in certain applications.
The diameter of the housing outlet 36 may be increased or decreased to adjust
the resistance and the amount of heat traveling through the housing outlet 36
and
exhaust pipe 112. The diameter of the exhaust pipe 112 and the housing outlet
36
effects the removal of moisture on pulverized material. Adjusting the outlet
diameter is
further discussed below.
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The pulverization and moisture extraction increases as the airflow generated
by
the airflow generator 32 increases. If airflow is increased or decreased, the
diameter of
the exhaust pipe 112 and housing outlet 36 may be decreased to provide the
same
material dehydration. Thus, the airflow and diameters may be adjusted relative
to one
another to achieve the desired dehydration.
Heavier materials with less water, such as rock materials, require less
moisture
extraction. With such materials, the housing outlet 36 and exhaust pipe 112
diameters
may be increased as less drying is required. Consequently, with wetter
materials, the
housing outlet 36 and the exhaust pipe 112 diameters may be decreased to
increase
the amount of air and heat to achieve the proper dehydration of the material.
The angle of inclination of the exhaust pipe 112 relative to the longitudinal
axis of
the venturi 18 and airflow generator 32 also effects dehydration performance.
The
exhaust pipe angle a may be approximately 25 degrees to approximately 90
degrees in
order to enhance moisture extraction. Material traveling upward is held back
by gravity
whereas air is less restricted by gravity. This allows the air to move faster
than the
material and increase moisture removal. The angle a may be adjusted to
increase or
decrease the effect on moisture extraction. The exhaust pipe 112 may be
straight as
illustrated or curved as shown in phantom.
The cyclone 114 is a well known apparatus for separating particles from an
airflow. The cyclone 114 typically includes a settling chamber in the form of
a vertical
cylinder 116. Cyclones can be embodied with a tangential inlet, axial inlet,
peripheral
discharge, or an axial discharge. The airflow and particles enter the cylinder
116
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through an inlet 118 and spin in a vortex as the airflow proceeds down the
cylinder 116.
A cone section 120 causes the vortex diameter to decrease until the gas
reverses on
itself and spins up the center to an outlet 122. Particles are centrifuged
toward the
interior wall and collected by inertial impingement. -The collected particles
flow down in
a gas boundary layer to a cone apex 124 where it is discharged through an air
lock 126
and into a collection hopper 128.
In certain applications, the system 100 may further include a condenser 130 to
receive the airtlow from the cyclone 114. The condenser 130 condenses the
vapor in
the airflow into a liquid which is then deposited in a tank 132. An outlet 134
couples to
the condenser 130 and provides an exit for air. As can be appreciated, the
condenser
130 has particular application with food processing. In an alternative
embodiment, the
condenser 130 is embodied as an alternative treatment device such as a
charcoal filter
or the like. As can be appreciated, condensation or filtering will depend on
the material
and application. The outlet 134 may include or couple to a filter (not shown)
to filter
residue, particles, vapor, etc. from the outputted air.
Passing material through the system 100 multiple times will further dehydrate
material and will further reduce particle size. In municipal waste
applications, multiple
cycles through the system 100 may be required to achieve the desired
dehydration
results. The present invention contemplates the use of multiple systems 100 in
series
to provide multiple venturis 18 and multiple pulverization events. Thus, a
single cycle
through multiple systems 100 in series achieves the desired results.
Alternatively,
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material may be processed and reprocessed by the same system 100 until the
desired
particle size and dryness is achieved.
In one implementation, the resulting product issuing from a system 100 is
analyzed to determine the size of the powder granules andlor the moisture
percentage.
If the product fails to meet a threshold value for size and/or water
percentage the
product is directed through one or more cycles until the product meets the
desired
parameters.
The present invention allows homogenization of different materials. In
operation
different materials enter the inlet tube 12 together, are processed through
the venturi
18, and undergo pulverization. The resulting product is blended and
homogenized as
well as being dehydrated and reduced in size.
A particular application of the present invention involves the homogenization
of
landfill product with coal. After pulverization and water extraction, the
combined and
homogenized waste and coal product is used in a coal burner to achieve optimum
burning rates for creating steam in an electrical generation plant. The waste
is used for
energy production rather than for routine disposal.
If desired, the material may be mixed in the blender 102 prior to
pulverization or
at an intermediate stage between pulverization events. Mixing materials may
enhance
homogenization with certain materials. If desired, the material may be mixed
in the
blender 102 prior to pulverization or at an intermediate stage between
pulverization
events.
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Materials blended in a preprocessing stage may be cycled through multiple
pulverizing stages to provide the desired homogenization. A first material may
be
processed through multiple pulverizing stages and then homogenized with a
second
material. Between pulverizing stages the second material may be blended with
the
processed material in a preprocessing stage. The first and second materials
are then
passed through one or more pulverizing stages to produce a homogenized, final
product.
As an additional example, a first material may cycle through three pulverizing
stages. After the third pulverizing stage, a second material may be blended
together in
a blender 102. Before mixing, the second material may have passed through a
venturi
18 for pulverization and reduction to a desired particle size. The first and
second
materials may then pass together through one or more additional pulverizing
stages to
provide the desired moisture content, size, and homogenization for industrial
use.
Referring to Figure 6, a perspective view is shown of a housing 200 that
includes
a housing outlet 202. The housing 200 encompasses the operational components
of an
airflow generator 32. The housing 200 is shown with a cut-away section to
illustrate the
airflow generator 32 within. In order to provide variance in the output flow,
a restrictor
204 may be introduced into the housing outlet 202. A restrictor 204 increases
the
resistance to the airflow and also increases heat. Varying the amount of
resistance and
airflow is dependent on the material to be processed.
A restrictor 204 includes a~~neck 206 to nest within the housing outlet 202
and a
restrictor aperture 208. The restrictor aperture 208 has a cross-section less
than that of
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the housing outlet 202. A restrictor aperture 208 may be rectangular,
circular, or have
another suitable shape. The neck 206 provides a converging flow path from a
cross-
section approximating that of the outlet 202 to the final cross-section of the
restrictor
aperture 208. A number of restrictors 204 with varying aperture sizes may be
available
to manipulate the output flow and thereby tune the system 100 to suit the
material.
Referring to Figure 7, a cross-sectional view of an airflow generator 32
within a
housing 200 is shown. The airflow generator 32 may not be coaxially aligned
within the
housing 200. In one implementation, the airflow generator 32 includes a
diverter plate
250 that has a cutting edge 252 near the airflow generator 32. The cutting
edge 252 of
the diverter plate 250 directs pulverized material into the housing outlet
202. The
diverter plate 250 is coupled to the interior of the housing 200 and may be
coupled to
the interior of the housing outlet 202.
The diverter plate 250 prevents pulverized material from further rotation
within
the housing 200. As such, the diverter plate 250 serves as the first
separation of
pulverized material from air that continues to rotate within the housing 200.
Subsequent
separation of pulverized material from air is performed by the cyclone114. If
pulverized
materials continue to rotate within the housing 200 the pulverized materials
may build
up and eventually obstruct the airtlow generator 32. The cutting edge 252
varies the
airflow volume proceeding through the housing 200.
The separation of the cutting edge 252 of the diverter plate 250 from the
airflow
generator 32 may range from about 20 thousandths of an inch to 100 thousandths
of an
inch. The position of the diverter plate 250 may also be adjustable to
increase or
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decrease the separation from the airflow generator 32. Adjustment may be
required
depending on the materials being processed or to manipulate airflow volume.
Adjustment may be controlled by the central processor 110 which communicates
with
an electromechanical or pneumatic device for moving the diverter plate 250.
The
cutting edge 252 has a bevel that accommodates the shape of the airflow
generator 32.
Referring to Figure 8, a cross-sectional view of a venturi 18 with an
accompanying throat resizer 300 is shown. The throat resizer 300 is a
removable
component that, when inserted, nests within the throat 28. The throat resizer
300 alters
the effective diameter of the throat 28 and increases the air velocity.
Variance of the
throat diameter is required depending on the material and the desired
dehydration and
particle reduction. Thus, although the airflow generator 32 may vary the
airflow, it is
further desirable to manipulate throat diameter of venturi 18.
The throat 28 may be configured with a ledge 302 upon which a collar 304 of
the
throat resizer 300 nests. A crown member 306 is coupled to the collar 304 and
conforms to the interior surface of the converging portion 26. The throat
resizer 300
includes a sleeve 308 that conforms to the interior surface of the throat 28
and extends
within a major portion of the venturi throat length to resize the venturi 18.
Referring to Figure 9, an alternative embodiment of a system 400 is shown that
incorporates two pulverizing stages 402, 404. Each time material passes
through a
venturi 18, pulverization occurs, moisture is extracted, and particle
reduction occurs. As
discussed previously, this process may be repeatedly performed with a single
venturi 18
or with multiple venturis 18 in series until the desired amount of water is
extracted and
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21
product size is achieved. This process may be continued until nearly 100
percent water
extraction is achieved.
Although two pulverizing stages are shown with the system 400, one of skill in
the art will appreciate that a system may include three, four, five, or more
stages. The
first pulverizing stage 402 is similar to that previously described in
reference to Figures
4 and 5. The first pulverizing stage 402 includes a hopper 22, blender 102,
conveyance
device 104, flow control valve 106, venturi 18, housing 35 (with an airflow
generator 32
within), and an exhaust pipe 112. The system 400 may further include a flow
control
valve 405 in the exhaust pipe 112 to regulate airflow within.
As in the previous embodiments, the exhaust pipe 112 couples to a cyclone 114
to separate the processed product from the air. The system 400 may further
include a
second cyclone 406 to receive air from the outlet 122 of the first cyclone
114. The
second cyclone 406 further separates air from residual particles and delivers
the
purified air to a condenser 130. A first tank 132 is in communication with the
second
cyclone 406 to receive condensed liquid from the condenser 130. An outlet 134
provides an exit for air passing from the condenser 130 and the second cyclone
406. A
residual hopper 408 is positioned to receive residual particles from the
second cyclone
406.
Particles separated by the first cyclone 114 are delivered to a hopper 410
using
any number of conventional techniques including gravity. Although not shown,
particles
from both the first and second cyclones 114, 406 may be delivered to the
hopper 410.
The hopper 410 receives the particles that then undergo the second pulverizing
stage
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404. The hopper 410 delivers the particles to a second inlet tube 412 that is
coupled to
a second venturi 414 as with the first pulverizing stage 402.
One or more flow valves 416 are located on the second venturi 414 and are in
electrical communication with the central processor 110. The flow valves 416
function
similar to those previously described and referenced as 111.
The second venturi 414 communicates with a second airflow generator (not
shown) in a housing 418. The second airflow generator generates a high speed
airflow
through the venturi 414. The second housing 418 couples to a second exhaust
pipe
420 that delivers air and processed material to a third cyclone 422. The
second
exhaust pipe 42'0 is inclined at an angle of approximately 25 degrees to
approximately
90 degrees relative to the longitudinal axis of the second venturi 414. A
second flow
control valve 424 is within the second exhaust pipe 420 to regulate airflow
within. As
with the first flow control valve 404, the second flow control valve 424 is in
electrical
communication with the central processor 110 for regulation.
The third cyclone 422 separates the particles from the air and delivers a
product
that is delivered to another conveyance device 425. A fourth cyclone 426
receives air
from the third cyclone 422 and further purifies the air and removes residual
particles.
Residual particles from the fourth cyclone 426 are deposited in a residual
hopper 428.
The fourth cyclone 426 delivers air to~a second condenser 430 where vapor is
condensed into a liquid and received by a second tank 432. An outlet 434
couples to
the second condenser 430 to allow air to exit.
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The system 400 further includes a heat generator 436 to provide heat through
the inlet tubes 12, 412 and the venturis 18, 414 and assist in drying
materials. The
addition of heat is not required for water extraction and is merely used to
further
increase the drying potential of the present invention. The heat generator 436
may
communicate with the hoppers 22, 438 or with the inlet tubes 12, 412. A heat
generator
436 may also be used in a similar manner in the embodiments illustrated in
Figures 1, 2,
4, and 5.
In Figure 9, the heat generator 436 is in communication with a first heat
control
valve 440 to deliver heat to the first hopper 22. The first heat control valve
440 is in
electrical communication with the central processor 110 to regulate the heat
delivery.
Alternatively, the heat control valve 440 may be operated manually. The heat
generator
436 is further in communication with a second heat control valve 442 that
regulates heat
flow to hopper 438. Heating material during the second pulverizing stage 404
may be
desired depending on the material or the application. If heating is desired,
the hopper
438 receives particles from the first cyclone 114. Otherwise, the material may
pass to
the hopper 410 as illustrated in Figure 9.
The system 400 may include one or more pulverizing stages for further
dehydration and particle reduction. The conveyance device 425 may feed back
into the
blender 102 or the hopper 22 for further cycling of product through the
pulverizing
stages 402, 404. The second and fourth cyclones 406, 426 provide further
purification
of air but the added cost may not be justified for certain applications. In
certain
applications the condensers 130, 430 may be removed or another type of
treatment
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apparatus, such as a filter, be used. Flow control valves may also be
introduced or
removed throughout the system 400 as warranted and as based on design
constraints.
Referring to Figure 10 an alternative embodiment of a pulverization and
moisture
extraction system 450 is shown. The system 450 is similar to that of Figures 4
and 5
and further includes a second cyclone 406 in communication with the first
cyclone 114,
a residual hopper 408 to collect particles from the second cyclone 406, a
condenser 130
in communication with the second cyclone 406, a tank 132 in communication with
the
condenser 130, and an outlet 134 coupled to the condenser 130. The system 450
further includes a diverter valve 452 coupled to the first cyclone 114.
The diverter valve 452 directs particles received from the first cyclone 114
to a
first outlet 454 or a second outlet 456. The first outlet 454 is coupled to a
collector 458
such as a bag, hopper, tank, or the like. The second outlet 456 is coupled to
a recycling
tube 460 to introduce the pulverized material through the system 450 again.
The
recycling tube 460 is coupled at its opposing end to the first end 14.
Alternatively, the
recycling tube 460 may direct pulverize material into the hopper 22 or
directly into the
elongated opening 20.
In operation, material is pulverized as it passes through the system 450 and
is
redirected, by control of the diverter valve 452, to pass through the system
450 again for
another pulverization event. This may be repeated as desired until a final
product
results which is then directed by the diverter valve 452 into the collector
458.
Referring to Figure 11, an embodiment of an airflow generator 500 suitable for
the present invention is shown. Various metals are suitable for the airflow
generator,
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depending on the material to be processed. For abrasive material, a harder
alloy steel
may be used. The material selected has to strike a balance between strength
and
anticipated wear. Casting of the airflow generator 500 is advantageous as
fabrication
via welding creates inconsistent surfaces and heat effected areas due to heat
effected
zones. The cast airflow generator 500 may have a variable material thickness
to resist
rapid structural impacts and accelerated wear resulting from processing
various
materials. The section thickness and resulting total weight of the airflow
generator 500
is directly proportional to the air volume and material flow rate that is to
be processed.
The airflow generator 500 is received within a housing such as that
illustrated in
Figure 6. The housing 200 at least partially encircles the airflow generator
500 and
preferably completely encircles the airflow generator 500 so that the only
egress is the
housing outlet 36. The airflow generator 500 may have a close clearance to the
housing 200 to generate additional friction and heat. The heat is desired to
assist in
further drying materials passing through the airflow generator 500 and into
the exhaust
pipe 112.
The airflow generator 500 includes a front plate 502 with a concentrically
disposed input aperture 504 to receive incoming materials. The diameter of the
input
aperture 504 is variable depending on the processed material size and
anticipated air
volume. A back plate 506 parallels the front plate 502 and includes a
concentrically
disposed axle aperture 508. As the name suggests, the axle aperture 508
receives and
engages an axle or spindle to power rotation. Alternative airflow generators
500 may be
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used with the present invention and include generators with a single back
plate coupled
to blades or generators with radially extending blades alone.
The back plate 506 may further include bolt apertures 509 that are disposed
concentrically around the axle aperture 508. The bolt apertures 509 each
receive a
corresponding axle bolt (not shown) that are each coupled to an axle. The axle
bolts
are secured to back plate 506 by nuts or other conventional devices.
Although the thickness of the front and back plates 502, 506 may vary
considerably, in one design the back plate 506 is approximately 3/8" (8 mm)
and the
front plate 502 is 3/16" (5 mm).
A plurality of blades 510 are disposed between the front and back plates 502,
506 and are coupled to both plates 502, 506. As can be appreciated, the number
of
blades 510 may vary and depends, in part, on the material to be processed. The
thickness of the blades 510 may also vary depending on the material to be
processed.
In one embodiment, the blades 510 extend through the front and back plates
502, 506 to form blade fins 511 on the exterior face of the front and back
plates 502,
506. The blade fins 511 may extend approximately 1/2" (12 mm) from either the
front or
back plates 502, 506. The blade fins 511 generate a cushion of air between the
airflow
generator 500 and the interior of the housing 200. The blade fins 511 further
act to
clean out materials that may enter between the housing 500 and the airflow
generator
200.
Referring to Figure 12, a cross-sectional view of the axle aperture 508 is
shown.
The axle aperture 508 receives an axle, shaft, spindle, or other member to
rotate the
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airflow generator 500. The bolt apertures 509 each receive an axle bolt to
secure the
back plate 506. In this embodiment, an axle transitions from a first diameter,
with axle
bolts extending, to a second diameter suitable for insertion into the axle
aperture 508.
The bolt apertures 509 may each provide a well 513 to receive a nut that
engages an
axle bolt.
Referring to Figure 13, a plan view of the interior of the airflow generator
500 is
shown with a single blade 510. The single blade 510 is shown to illustrate the
unique
features of blades 510 incorporated within the airflow generator 500. The
remaining
blades 510 are similarly embodied.
The blade 510 extends from a trailing edge 512 at the perimeter 513 of the
back
and front plates 502, 506 to a leading edge 514 adjacent the axle aperture
508. The
blade 510 includes a wedge portion 516 adjacent the trailing edge 512. The
wedge
portion 516 has a thicker cross-section to increase pressure and airflow
volume. The
wedge portion 516 provides increased resistance to wear which is advantageous
with
some materials.
Referring to Figure 14A, a plan view illustrating the wedge portion 516 in
greater
detail is shown. The shape of the wedge portion 516 affects airflow volume,
airflow
velocity, and material flow rate through the airflow generator 500. The wedge
portion
516 may be altered in the circumferential and longitudinal direction to alter
airflow
volume, airflow velocity, and material flow rate. Casting techniques
advantageously
allow variance in three dimensions and allows any number of circumferential
and
longitudinal profiles in the wedge portion 516.
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The increased thickness of the wedge portion 516 enhances the life of the
airflow
generator 500 as this is where the blade 510 typically experiences the most
wear. The
material used and the hardness of the wedge portion 516 may also differ from
the
remainder of the blade 510.
Referring to Figure 14B, an alternative embodiment of a wedge portion 518 is
shown which includes a replaceable wear tip 520. With the airflow generator
500
rotating in a clockwise direction, the replaceable wear tip 520 is subject to
the most
material contact. Although thickened to increase wear resistance, the wedge
portion
518 is subject to more wear than other components of the airflow generator 500
and
may wear out sooner. By replacing the replaceable wear tip 520, replacement of
the
entire airflow generator 500 is deferred. The replaceable wear tip 520 is
coupled to the
remainder of the wedge portion 518 through any known fastening device
including a
securing nut and bolt assembly 522. The replaceable wear tip 520 may be a
material
harder than the remainder of the blade 510. The replaceable wear tip 520 may
also be
replaced with a replaceable wear tip 520 having a different circumferential
and
longitudinal profile. In yet another embodiment, the entire wedge portion 518
is
replaceable.
Referring to Figure 15A, a perspective view of the airflow generator 500 is
shown
illustrating the wedge portion 516 coupled to the front and back plates 502,
506. The
blade fins 511 are further shown extending from the exterior surface of the
front and
back plates 502, 506. As shown, the wedge portion 516 is substantially thicker
than the
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corresponding blade fins 511. The blade fins 511 are not subject to the same
wear as
the wedge portion 516 and are not as thick.
Referring to Figure 15B a perspective view of the airflow generator 500 is
shown
with an alternative embodiment of the wedge portion 516. The wedge portion 516
increases its thickness and its circumferential profile as it extends in the
longitudinal
direction from the front plate 502 to the back plate 506. The wedge portion
516 also
increases in thickness as it extends radially towards the perimeter.
Pulverized material entering into the airflow generator 500 has a tendency to
accumulate proximate to the back plate 506. The longitudinally increasing
thickness
encourages pulverized material to remain centered between the front and back
plates
502, 506 rather than accumulating along the back plate 506. Casting techniques
enable
production of such a wedge portion 516 as three dimensional variation is
possible. The
replaceable wear tip 520 may include and define the longitudinally increasing
thickness.
If another wedge portion 516 shape is desired another replaceable wear tip 520
without
a longitudinally increasing thickness or a more pronounced longitudinally
increasing
thickness may be used. Thus, pulverized material flow direction may be
manipulated
longitudinally by using wedge portions 516 of different circumferential and
longitudinal
configurations.
Referring again to Figure 13, the blade 510 transitions from a position
perpendicular to the back plate 506 to an angled position. .The blade 510
transitions as
it proceeds from the wedge portion 516 to a location prior to the leading edge
514. The
angled position causes the blade 510 to pitch into the direction of the
airflow.
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In the illustrated embodiment, a trailing portion 524 of the blade 510,
including
the wedge portion 516, extends perpendicular from the back plate 506. The
trailing
portion 524 may be approximately one fourth to one half of the blade 510 as
the blade
510 extends from the trailing edge 512 to the leading edge 514. A leading
portion 526
is the remaining amount of the blade 510 from the trailing portion 524 to the
leading
edge 514. The illustrated leading portion 526 has an angled transition from a
perpendicular position relative to the back plate 506 to an angled position.
The angled position has an angle that is referred to herein as the attack
angle as
it allows the leading edge 514 to cut into the incoming airflow. In Figure 13,
the final
attack angle of the blade 510 at the leading edge 514 is approximately 25
degrees. The
transition from a perpendicular position to an angled position may extend over
the entire
blade 510 or any portion thereof. The attack angle may be selected from a
broad range
of angles based on anticipated airflow velocity, material flow rate, and
material. The
angled position may have a range of approximately 20 to 60 degrees.
Alternatively, the blade 510 may remain perpendicular along its entire length.
The blade 510 may also have an attack angle along its entire length. Although
extending along the entire length, the attack angle may still vary as the
blade 510
extends from the trailing edge 512 to the leading edge 514.
Referring to Figure 16, a profile view of the leading edge 514 is shown.
Conventionally, an edge may be relatively straight and proceed on an angle
relative to
the back plate 506. In one embodiment of the present invention, the leading
edge 514
proceeds from the back plate 506 with an outwardly curving portion 528 and
then
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31
transitions into an inward curve 530. The outwardly curving portion 528
assists in
capturing air traveling into the input aperture 504 of the airflow generator
500. The
leading edge 514 so profiled is able to cut into air and improve the
efficiency of the
airflow generator 500.
Referring to Figure 17 a cross section of the leading edge 514 taken along
section 17-17 is shown. The leading edge 514 has an oval shaped cross-section
that
assists in slicing into incoming airflow.
Referring to Figure 18, a perspective view of the airflow generator 500 is
shown
without the front plate 502 to illustrate the blades 510. The illustrated
embodiment
includes nine blades 510 although the number is variable. Each blade 510
includes a
wedge portion 516 for added resistance to wear and to increase pressure and
airflow.
Each blade 510 further transitions from a perpendicular position to an attack
angle. The
attack angle inclines towards the clockwise position that corresponds to the
anticipated
rotation of the airflow generator 500. The airflow generator 500 can be
operated in the
counter-clockwise position and the blades 510 would consequently be inclined
in that
direction.
In operation, the rotating blades 510 generate a high speed airflow ranging
from
350 mph or greater and directs air and pulverized material into the input
aperture 504.
The leading edges 514 of the blades 510 cut into the air and pulverized
material and
direct both the air and pulverized material into flow paths 532 defined by the
blades 510
and extending from the input aperture 504 to the perimeter 513 of the front
and back
plates 502, 506. The flow paths 532 would have a maximum flow rate for
materials
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32
passing through. The wedge portions 516 push the air and pulverized material
to the
housing outlet 202 that is located within the housing 200. Although the
airflow
generator 500 provides unique features, one of skill in the art will
appreciate that any
number of devices may be used and are included within the scope of the
invention.
The present invention provides a pulverizing and dehydrating system that can
accommodate various materials and various flow rates. The systems described
herein
are scalable for the different applications and different sized materials and
any specific
component dimensions are given only as examples. Thus, a system may be sized
as a
bench-top model or as a large industrial-sized unit.
The systems 10, 100, 400, 450 disclosed herein may be mounted to a ground
surface and larger scale embodiments are more likely to be so constructed. '
Alternatively, a system may be mounted within or on a vehicle such as a truck,
trailer,
rail car, boat, barge, and so forth. Any vehicle that provides a sufficient
planar footprint
may be used. Having a mobile system is advantageous in certain applications
such as
agricultural harvesting, remote site treatments, demonstrations, and so forth.
Referring to a Figure 19, a block diagram representing a mobile system 600 is
shown. The system 600 includes components previously discussed such as the
inlet
tube 12, venturi 18, airflow generator 32, housing 35, motor 34, exhaust pipe
112, and
first and second cyclones 116, 406. The system 600 may include additional
elements
such as the blender 102, central processor 110, condenser 130, and so forth.
Systems
with a plurality of pulverization stages may be mounted on a vehicle in
similar manner.
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The system 600 includes a vehicle generically represented as 602 and providing
a sufficient footprint to support the assembled components. The system 600
further
includes a plurality of supports 604 that couple to the vehicle 602 and
support any
number of assembled components. The system 600 may further include a housing
606
that encompasses components of the system. The housing 606 protects the
components and dampens noise during operation.
One or more components of the system 600 may be removable to facilitate
transportation. For example, the first and second cyclones 116, 406 may extend
out of
the housing 606 and need to be moved during transportation. The cyclones 116,
406
may be removed entirely or partially dissembled prior to transportation.
Similarly a
blender 102 may be removable for transportation. The necessity of removing
components is based on the size of the system 600, vehicle 602, and other
design
constraints.
The housing 606 may accommodate a control room for a user to operate the
system 600. The housing 606 may include windows for viewing the components and
access for viewing, operation, repair, and inserting material to be processed.
The
system 600 may have any number of configurations based on convenience,
application,
and other design considerations.
Referring to Figure 20, a side view of an alternative embodiment 700 of the
present invention is shown. The illustrated embodiment 700 is similar to that
previously
depicted in Figure 4 and also includes an acoustical emission sensor 702 that
is
coupled to the housing 35. The acoustical emission sensor 702 may be embodied
as
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any number of commercially available products including the acoustical
emission
monitoring system (AEMS) manufactured by Schmitt Industries, Inc. of Portland,
Oregon. In one embodiment, the acoustical emission sensor 702 is a piezo-
ceramic
sensor capable of monitoring 50 KHz to 950 KHz resonant frequencies.
The acoustical emission sensor 702 monitors the high frequency signals
generated by material flowing through the inlet tube 12, venturi 18, airflow
generator 32,
and housing 35. The resonant frequency received by the acoustical emission
sensor
702 is indicative of the volumetric flow rate. Changes in the flow rate of
material
through the system 700 alter the resonant frequency
The acoustical emission sensor 702 is in electrical communication with a
sensor
controller 703 that receives the resonant frequency and calculates a flow
rate. The
sensor controller 703 is in electrical communication with the central
processor 110 that
receives the flow rate and may respond to adjust the flow rate. During normal
operation
the resonant frequency remains within normal operating parameters. System
failure
may result when the flow rate exceeds a threshold. Minimum and maximum values
may be established for the flow rates during normal operating conditions. If
the flow
rate is below the minimum value, the flow rate is increased and, likewise, the
flow rate is
decreased if it exceeds the maximum value.
The sensor controller 703 includes a predetermined maximum threshold value for
the resonant frequency. The maximum threshold value may be entered by an
operator
and is based on material to be processed and the constraints of the system
700. The
sensor controller 703 may also include a minimum threshold value for
performance. If
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the flow rate exceeds the maximum threshold value, an overload situation is
indicated
and the sensor controller 703 signals the central processor 110 that the flow
rate must
be adjusted. Similarly, if the flow rate is below the minimum threshold value,
the sensor
controller 703 so indicates to the central processor 110.
In addition to the flow rate, the acoustical emission sensor 702 receives
resonant
frequencies that indicate abnormal conditions such as improper balance of the
airflow
generator 32, dislodged blade 510, or other mechanical failure. An overload
situation
itself may create a mechanical failure. Such failure may result in significant
and even
catastrophic damage to the system 700. Mechanical failure may also create
flying
debris that is a possible danger to an operator. The acoustical emission
sensor 702
monitors the resonant frequencies and detects changes indicating failure as it
occurs.
As soon as an overload situation or failure is indicated, the sensor
controller 703 signals
the central processor 110 within one millisecond or less. The central
processor 110
responds with immediate corrective action. Alternatively, the sensor
controller 703 may
include visual or audible notification to inform an operator who then responds
with
manual corrective action.
The acoustical emission sensor 702 is shown disposed on a backside 704 of the
housing 35. Alternatively, the acoustical emission sensor 702 may be disposed
on a
frontside 706 of the housing 35 or any other location on the exterior housing
surface.
The acoustical emission sensor 702 may also be disposed on the venturi 18 or
the inlet
tube 12.
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Referring to Figure 21, a system 800 is shown wherein an acoustical emission
sensor 702 is disposed on the diverging portion 30 as well as on the backside
704 of
the housing 35. Multiple acoustical emission sensors 702 may be used to
improve
monitoring of the resonant frequencies. In alternative embodiments, a
plurality of
acoustical emission sensors 702 may be disposed on the housing 35, venturi 18,
andlor
inlet tube 12 to monitor the flow rate. A sensor controller 703 is in
electrical
communication with the acoustical emission sensors 702 to calculate a flow
rate.
The sensor controller 703 is in electrical communication with the central
processor 110 that receives data transfers within one millisecond of the
resonant
frequency event. If the flow rate approaches an overload condition, the sensor
controller 703 signals the central processor 110 to adjust the flow rate. The
central
processor 110 may adjust the flow rate by partially or completely closing the
adjustable
flow valves 111. Partial or complete closure of the flow valves 111 increases
airflow
through the venturi 18 to provide additional force and drive material through
the venturi
18 and the airflow generator 32. The central processor 110 may also partially
or
completely close the flow control valve 106 to reduce material into the system
700. If
the resonant frequency indicates a mechanical failure, the central processor
110 may
also perform a system shutdown and turn off the motor 34. The sensor
controller 703
may also provide a visual or audible response to an operator.
Referring to Figure 22, a cross-sectional view of an embodiment of an air
generator housing 200 is shown. As previously discussed, the position of the
diverter
plate 250 may also be adjustable to increase or decrease the separation from
the
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airflow generator 32. The central processor 110 may control the position of
the diverter
plate 250 by communicating with an actuator device 900 to move the diverter
plate 250.
The actuator device 900 may be embodied as an electromechanical device,
pneumatic
device, or other conventional device. The central processor 110 may adjust the
flow
rate by moving the diverter plate 250 in order to avoid an overload condition.
This
action may be taken simultaneously with adjustment of the flow valves 111
and/or the
flow control valve 106 to increase control of the flow rate.
One or more acoustical sensors 702 may also be disposed on systems illustrated
in Figures 1, 2, 9, and 19. Thus, the illustrated system 700 should be
considered for
exemplary purposes only and not limiting of the present invention.
Referring to Figure 23, a perspective view of an alternative embodiment of a
system 1000 is shown including the motor 34 and axle 33 adjacent the backside
704 of
the housing 35. The motor 34 engages a pulley 1002 that engages the axle 33 to
effect
high speed rotation of the axle 33. The axle 33, also referred to as a
spindle, couples to
one or more brackets 1004 to secure the axle 33 and fix its rotation. The
brackets 1004
are secured to a mounting plate 1006. The pulley 1002 is shown engaging the
axle 33
between two brackets 1004, although the pulley 1002 may engage the axle 33 in
other
locations as well.
The system 1000 further includes an automatic balancer system 1008 that
includes a dynamic balancer 1010, a vibration sensor 1012, and a balancer
controller
1014. Automatic balancer systems 1008 are easy to mount, highly reliable,
fully
automatic, and require little operator training. In Figure 23, the balancer
1010 is
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embodied as an external balancer 1010 although the balancer 1010 may also be
embodied as an internal balancer or ring balancer as discussed below. The
external
balancer 1010 is in electrical communication with a balancer controller 1014
to
compensate for unbalance in the axle 33 and the airflow generator 32 as the
axle spins
at working RPM levels. The balancer controller 1014 includes a processor (not
shown)
operating an algorithm to control the external balancer 1010.
The dynamic compensation reduces the noise and vibration and improves the
system's performance and the material flow rate through the airflow generator
32.
Dynamic balancing of the airflow generator 32 prevents cavitation and improves
the
performance of the airflow generator 32. External balancers are commercially
available
such as those manufactured by Schmitt Industries, Inc. of Portland, Oregon.
The
external balancer 1010 may receive power through a rotary slip ring power
transfer
system or through a non-contact power transfer system. ,
In Figure 23, the external balancer 1010 is coupled to a proximate end 1016 of
the axle 33. The axle 33 couples at a distal end (not shown) to the airflow
generator 32
that is within the housing 35. The external balancer 1010 couples to the axle
33
proximate to the backside 704, also referred to as the pulley side, of the
airflow
generator 32. In this manner, the external balancer 1010 does not interfere
with airflow
into the input aperture 508 of the air turbine 32.
The external balancer 1010 operates on a principle of mass compensation for
axle imbalance. In one embodiment, the external balancer 1010 includes two
movable
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eccentric weights. The external balancer 1010 drives each eccentric weight by
micro-
electric motors through a precision gear train.
Referring to Figure 24A, a diagram is shown illustrating an airflow generator
32
axially aligned with an external balancer 1010. An external balancer 1010 is
disposed
in a plane remote from a plane in which the airflow generator 32 is disposed,
such as in
Figure 23. The external balancer 1010 includes weights 1020 shown relative to
a
position of imbalance 1022. The balancer controller 1014 instructs the
external
balancer 1010 to reposition the weights 1020 to offset the position of
imbalance 1022.
This situation is referred to herein as opposite plane balancing, as the
weights 1020 in
one plane balance a mass, such as the airflow generator 32, in a second plane.
Referring to Figure 24B, a dynamic balanced situation is shown with the
weights
1020 compensating for the position of imbalance 1022. With opposite plane
balancing,
the weights 1020 must be in the same semicircle 1024 as the position of
imbalance
1022 in order to balance. The semicircle 1024 is defined as having the axle
center
1025. The external balancer 1010 is able to maintain precise balance even if
the axle
33 is stopped and restarted.
Referring to Figure 25A, a diagram is shown illustrating an airflow generator
32
once again aligned with an external balancer 1010. However, in this situation
the
external balancer 1010 is adjacent the airflow generator 32 and therefore
substantially
within the same plane. This is referred to herein as same plane balancing. The
weights
1020 are shown relative to a position of imbalance 1022 and an unbalanced
condition
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exists. The balancer controller 1014 instructs the external balancer 1010 to
reposition
the weights 1020 to offset the position of imbalance 1022.
Referring to Figure 25B, a dynamic balanced situation is shown with the
weights
1020 compensating for the position of imbalance 1022. With same plane
balancing, the
weights 1020 are disposed in an opposing semicircle 1026 than the position of
imbalance 1022 to provide balance.
Referring to Figure 26A, a perspective diagram is shown illustrating operation
of
the opposite plane balancing technique. An external balancer 1010 is coupled
to an
axle 33 and rotates within a first plane 1030. A mass 1032, such as an airflow
generator 32, is coupled to an opposing end of the axle 33 and rotates within
a second
plane 1034. Accordingly, the external balancer 1010 and mass 1032 are on
opposing
ends of the axle 33. The weights 1020 within the external balancer 1010
compensate
for a position of imbalance 1022 in the mass 1032.
The opposite plane balancing technique is applied in the system 1000 of Figure
23 with the mass 1032 being the airflow generator 32. The external balancer
1010 and
the airflow generator 32 are mounted on opposing ends of the axle 33 to
precisely and
dynamically balance the airflow generator 32. The pulley 1002 couples to the
axle 33
between the external balancer 1010 and the airflow generator 32 although the
pulley
1002 may couple to the axle 33 at other locations as well. The compensating
weights
1020 create balance in the same semicircle but in a different plane of the
position of
imbalance 1022.
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Referring to Figure 25B, a perspective diagram is shown illustrating operation
of
the same plane balancing technique. The mass 1032 and external balancer 1010
are
disposed adjacent one another so that they are approximately within the same
plane
1036. The external balancer 1010 couples to an axle 33 that also couples to
the mass
1032. The weights 1020 must be in an opposing semicircle than the position of
imbalance 1022 in order to provide balance. The system 1000 shown in Figure 23
can
be modified to provide same plane balancing.
Referring again to Figure 23, the dynamic balance system 1008 includes the
vibration sensor 1012 that accurately monitors vibration levels that indicate
imbalance.
The sensor 1012 couples to the brackets 1004 or mounting plate 1012 by
magnets, stud
mounting, or other conventional methods. The vibration sensor 1012 is in
electrical
communication with a balancer controller 1014, which filters incoming signals
by RPM.
The balancer controller 1014 is in communication with the external balancer
1010 and
drives the weights 1020 in the direction that reduces the amplitude of the
vibration
signal. When the weights 1020 are positioned so the lowest vibration level is
reached,
the balance is complete and the dynamic balance system 1008 monitors the
vibration
levels to assume optimum operations.
Referring to Figure 27, a cross-sectional view of an alternative embodiment of
a
dynamic balancer 1040 is shown. The dynamic balancer 1040 is an internal
balancer
1040 that completely or partially nests within a bore of the axle 33. Internal
balancers
are commercially available such as those manufactured by Schmitt Industries,
Inc. of
Portland, Oregon. The internal balancer 1040 may include a mounting flange
1042 that
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bolts to the axle 33 through one or more bolts 1044. Other conventional
methods exist
for securing the internal balances 1040 to the axle 33.
As with the external balances 1010, the internal balances 1040 positions
weights
to compensate for a position of imbalance in a mass. The internal balances
1040 may
be used with a balance system 1008 shown in Figure 23 and may be used for
opposite
plane or same plane balancing techniques. Accordingly, the internal balances
1040
communicates with a balances controller 1014 to dynamically position the
weights. As
previously discussed, the balances controller 1014 communicates with a
vibration
sensor 1012 to determine a posifiion of imbalance.
Referring to Figure 28, a cross-sectional view of one embodiment of
compensating weights 1046, 1048 used by the internal balances 1020 is shown.
The
compensating weights 1046, 1048 may be embodied as semi-circles and rotate
relative
to one another in an over and under configuration. As shown, an inner
compensating
weight 1046 has a thicker cross-section than an outer compensating weight
1048. By
precisely positioning the compensating weights 1046, 1048, dynamic balance is
achieved. The illustrated compensating weights 1046, 1048 may also be used in
an
external balances 1010.
Referring to Figure 29, a perspective view of an alternative dynamic balances
1050 is shown. The dynamic balances 1050 is a ring balances 1050 that
encircles and
couples to an axle 33. Ring balancers are commercially available such as those
manufactured by Schmitt Industries, Inc. of Portland, Oregon. As such, the
ring balances
1050 may be disposed at any accessible location along the length of the axle
33. The
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ring balancer 1050 may be used with a balance system 1008 shown in Figure 23
and
may be used for opposite plane or same plane balancing techniques.
Referring to Figure 30, a cross-sectional view of one embodiment of a ring
balancer 1050 is shown. The ring balancer 1050 includes compensating weights
1052,
1054 that may be disposed axially side-by-side relative to one another. A
first
compensating weight 1052 may have greater mass than a second compensating
weight
1054. Positioning the compensating weights 1052, 1054 creates an overall
compensation counterweight to a position of imbalance to achieve dynamic
balance.
Alternatively, the ring balancer 1050 may incorporate compensating weights
similar to
those disclosed in the previously described dynamic balancers 1010, 1040.
Alternative balancer embodiments are known in the art and can be used. The
automatic balancer system 1008 dynamically balances the airflow generator 32
at
operational speeds to maintain optimal balance. Balance is maintained after
rotation
ceases and during subsequent operations. Balancers may couple to the axle 33
on the
pulley side to avoid interference with airflow into the airflow generator. The
automatic
balancer system 1008 eliminates cavitation to improve efficiency and
performance of
the airflow generator.
