Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: Method for Assessing the Operation of a Convevina
Apparatus
FIELD OF THE INVENTION
The present invention is directed to a method for
measuring the weight of material, such as rock, sand,
gravel, earth, wood, grain, cement, etc., being processed
by an apparatus such as a conveyor or bucket elevator
system by an electric motor. In particular, the method
is directed to converting electrical power consumption of
the electric motor powering the apparatus into weight per
hour movement of raw material processed by the apparatus.
The second part of this invention is using the tonnage
rate measurements combined with a "no load" time as a new
means of assessing daily production at each step in the
process. Finally in a quarry or mine site where blasting
of rock is used as a first step in breaking down rock for
processing it is possible to use these tonnage rate
readings if set up at several key steps in the crushing
and screening process as a new method to evaluate blast
fragmentation results.
BACKGROUND OF THE INVENTION
In many mining, quarrying, sand and gravel or pulp
and paper operations it is desirable to measure the
amount of raw material, such as aggregate, gravel, ore,
pulp etc. being processed or moved, in order to maximize
production at the operation. In the past, this has been
accomplished either by weighing the amount of material
loaded into transport vehicles, such as trucks or railway
cars or through the use of auto weigh feeders, belt
scales, or load cells all based on the use of strain
gauge load cells combined with high speed sensors to
measure tonnage. This can be an expensive set up,
requiring installation of new equipment, wiring and
material testing for calibration for each piece of
equipment to be monitored. To maintain accuracy the belt
scales or load cells also require regular calibration and
zeroing of cells.
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There remains a need for a means of measuring the
amount of material being processed or moved in an
operation such as a quarrying or mining operation which
is inexpensive, simple to setup and operate and to adapt
to existing operations. There is also a need to know how
efficient the operation is running i.e. each step in a
quarry, mine or sand and gravel operation is designed to
move a certain quantity of material daily at an hourly
rate. At some steps in the operation downtime may occur
and if a record is measured of this downtime or "no load"
then this becomes an area that can be improved to
increase production. Ideally an operator wants the
process to run at design production rates with minimum
downtime to maximize production. This invention will
provide the measurement tools at a low cost to achieve
this goal. In addition if measurements are made at the
conveyors coming off the primary and secondary crushers
and at some key conveyors going to final stockpiles then
these measurements can be used as a new method to compare
blasting results.
One apparatus the KiloWate TP4 conveyor belt scale
is available using a similar approach based on patent
3,942,625. The invention described here in is based on a
new method to calibrate the device, which increases
precision and includes new applications for the use of
this device, which will help industry to become more
productive. This invention is an improvement over an
earlier application number JJ-11 384US(USA) and number
JJ-384CA(Canada) by Steve McIassac who has worked with
the current inventor to improve the accuracy and scope of
this new invention over the earlier which focused on the
lower cost version based on current readings. Using this
invention provides a new approach to automation control
in mines, quarries and pulp and paper operations where
this system may operate in parallel with existing systems
thereby insuring no loss of data should an error or
breakdown of a currently used belt scale occur.
In Automation Control the Belt Scale is the most
widely used device to measure weight of material movement
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however these devices are installed as separate equipment
on a conveying device. If a breakdown or error develops
with the belt scale while the conveyor is operating then
often the conveyor will continue to operate until a
convenient time arrives to make a repair or adjustment
with the scale with resulting loss of data. With the use
of the device described in this invention the readings
come from the motor operating the conveying device and
should any failure or problem develop with the motor or
conveying device then the system if shut down for repairs
will also stop recording data at the same time, hence no
loss of data. For areas of a process where belt scales
are installed and provide key information for batch
processing then the new apparatus in this invention could
be installed at a low cost as a parallel system
integrated with the logical of the belt scale to provide
an early warning system of any errors or deviation in
readings above a specified acceptable error range. The
other important function of this invention is the
continual recording of any "no load" times as well as
"over load or start-up load" times. All of these times
represent lost production and can also lead to early
failure of motors if the "start-up load" time occurrences
become to frequent and occur with a conveyor loaded i.e.
a conveyor motor will require a large power surge to
start operating if the conveyor is fully loaded. This
surge can result in increased billing if monthly rates
are based on peaks and these start-up surges will shorten
the life of large industrial electric motors.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus
and method for measuring the weight of material such as
rock, earth, wood, pulp, grain, gravel, sand, ore, cement
etc. being processed or moved by an apparatus such as a
conveyor or bucket elevator driven by an electrical
motor. The apparatus comprises a means for measuring the
electrical energy consumed by the motor powering the
apparatus during operation of the apparatus and a
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calibration formula for converting the power consumption
of the motor to tonnage per hour of raw material
processed by the apparatus.
In an aspect of the invention a continual record
is kept of all "no load" and "start-up load" time during
the recording process and these figures are totalized
along with tonnage for the recording period.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention are
shown in the drawings, wherein:
Figure 1 is a picture of a typical set-up in a
quarry with a computer showing live the data being
collected from the conveyor motor with also a Real-Time
graph of data being displayed;
Figure 2 is a picture of the components making up
the apparatus of the present invention using a watt
transducer and current transducers for demonstration
purposes;
Figure 3 is a picture showing the Tonnage Analyzer
Instrument case with two Data Loggers and watt transducer
installed;
Figure 3b is a picture showing a typical watt
transducer installed for a conveyor motor Tonnage
Analyzer. Also illustrated is a clamp AMPROBE CT
installed for current tonnage conversion;
Figure 4 is a schematic drawing showing a typical
layout of the components of the invention;
Figure 5 is a typical wiring diagram showing a
watt transducer installation;
Figure 6 is a graph illustrating the method used
to calibrate a typical conveyor belt with the resulting
regression formula to convert amperes to tons (tonnes)
per hour for typical conveyor belt;
Figure 7 is a graph illustrating the method used
to calibrate a typical conveyor belt with the resulting
regression formula to convert kilowatts to tons (tonnes)
per hour for typical conveyor belt;
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Figure 8 is a table illustrating the correlation
between the method of the present invention and actual
measurement of tonnage recorded by a recently calibrated
Techweigh Belt scale (Figure 1) of material processed in
a typical quarry over several weeks of operation.
Measurements in kilowatts and amperes are converted to
tonnage using the current invention-taking place with a
single conveyor belt;
Figure 8b is a table illustrating the correlation
between the method of the present invention and actual
measurement of tonnage recorded by a recently calibrated
Milltronics Belt scale of material processed in a typical
quarry over several weeks of operation. This table
illustrates the conversion of kilowatts to tonnes
compared to the daily belt scale readings. The No-Load
and Start-Up load times that could be used to increase
production are also illustrated;
Figure 9 is a typical graph of kilowatt readings
from a motor being monitored;
Figure 10 is a summary of daily data from a
conveyor motor showing converted kilowatt readings to
tonnage compared to belt scale reading for the same
conveyor. Also illustrated are the hours of lost
production due to "no load and start-up load"
occurrences;
Figure 11 is a typical graph of ampere readings
from a motor being monitored;
Figure 12 is a summary of daily data from a
conveyor motor showing amp readings converted to tonnage
compared to belt scale reading for same conveyor. Also
shown are the hours of lost production due to "no load"
"start-up load" occurrences;
Figure 13 is a typical Real Time graph showing
te/hr converted from a watt transducer and a graph of
amps from the same conveyor motor showing the close
correlation in both systems;
Figure 14 is a graph showing typical power
consumption in kilowatts of a primary crusher;
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Figure 15 is a spread sheet showing that average
kilowatts used by a crusher during a typical days
operation including "no-load" time or lost production.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiment of an apparatus according
to the present invention is illustrated by the pictures
in figure 1, 2 and 3 and the schematic drawing, figure 4.
The apparatus is used with a conveyor system which has a
motor 13 which is used to drive a conveyor belt system
12. The motor 13 is electrically powered with the
electrical power being provided by wires 11, connected to
a suitable source of electrical energy such as the local
electrical grid or a local generator. As the conveyor
motor 13 operates to drive the conveyor system 12 it
draws the required electrical energy from the electrical
power source. The amount of electrical energy drawn by
the motor 13 is related to the load placed upon the motor
13 which in turn is related to the weight of material on
the conveyor system 12.
In order to measure the amount of electrical energy
being drawn by the motor 13, a suitable means for
measuring the power consumption of the motor is utilized.
To obtain an actual measurement of the power consumption
a watt transducer measuring device as seen in figure 3,
is connected to the motor as shown in the typical wiring
diagram Figure 5. In some applications if less precision
(+or- 3~) is acceptable it was found that using a current
Transducer (CT) ( Figure 2, item 4 or 5) to measure the
current passing through one of the line wires supplying
power to the conveyor motor, provided a close correlation
to watts being consumed with commercial grid
installation. This means for measuring the electrical
energy may be hardwired into the system by being
connected in series or parallel with the motor 13
depending upon whether the current or kilowatts are being
measured. Preferably, in order to easily adapt the
apparatus of the present invention to existing mining,
quarry or pulp and paper operations, the measuring device
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is selected so that it can be easily wired into the power
distribution panel for the motor operating the conveyor
or bucket elevator. For the watt transducer direct
connection to Line 1(R),2(S) and 3(T) for voltage input
and Current transducers are attached to line 1(R) and
3(T) using split core or donut style CT's (instrument
grade quality to insure accuracy of readings). One
example of a watt transducer used is a GMI watt
transducer with donut style CT~s (figure 2)
For current applications either clamped or split
core transducers are attached to one of the line wires,
figure 3b, item 4 for the conveyor motor and provide an
indication of the current passing through the wire. One
example of such a device is an AMPROBE current clamp,
item 4 or a GREYSTONE Split Core Current Transducer, item
5.
The output of the measuring device whether it is a
watt transducer or current transducer item 4, 5 or 6 are
connected to a suitable recording device such as an ACR
Smart Reader Plus 3 or Plus 7 data loggers, item 7 or a
programmable logic controller (PLC), item 14 which
records and stores the electrical readings. The data
from the data logger,item 7 or PLC, item 14 is passed to
a suitable computer, item 9 or SCADA, item 15 which
converts using calibration formulas the electrical
readings recorded by the data logger, item 7 into tonnage
per hour of material passing over the conveyor system 12.
This information may be provided on a live basis using
Real Time software (as supplied by ACR) or Dynamic Data
exchange (DDE) transfer of data to a central computer,
item 15 spread sheet, via modem or direct connection
using a RS235 cable, item 8.
For set ups where weight measurements are to be
incorporated as part of automation controls, the output
signal from the watt transducer (highest accuracy) in a
0-5 volt or 4-20 ma format can be fed to a programable
logic controller (PLC), item 14 for conversion to tonnage
and relayed to a SCADA or central computer, item 15 for
totalizing or operation of other equipment.
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The present invention is based on the measurement of
electrical energy supplied to an electrical motor driving
a processing apparatus such as a conveyor or bucket
elevator system either by the utility power grid or a
generator. The electrical energy supplied by the utility
power grid is normally well-balanced in the three phases
allowing the system of the present invention to measure
the kilowatts or simply the current component on one wire
feeding the motor to determine the tonnage per hour for a
preselected interval. The typical electrical motor
operating a piece of equipment such as a conveyor or
bucket elevator system in a mine, quarry, sand and gravel
or pulp and paper plant will consume a certain amount of
electrical energy for a short period after start-up to
initially turn over the motor-"Start-up load". A second
level of power consumption is reached to operate a piece
of equipment in an idle manner with no load of material
applied to the equipment- "no load". If the equipment
settings are kept the same i.e. the angle of the
conveyor, length of the conveyor, size, speed, no mud
build-up etc. or in the case of a bucket elevator if
settings are kept the same, then once the load is
applied, the additional power consumed to move or crush
the material is directly proportional to the weight of
the load so long as at least a minimum load of about 10
percent of the total load is applied on the equipment.
One of the keys to this invention is the calibration
graph (Figure 6 & figure 7) developed which clearly shows
a linear relationship once a small load has been applied.
However, this line does not intersect the "X" axis at the
no load setting if projected downward, i.e. it always
intersects at a point lower than the no-load setting if
projected to this "X" axis.
The electrical consumption of the power is
measured as kilowatts or electrical current in amperes
measured over short intervals between 1 and 8 seconds
(the faster sampling rate increases accuracy) per reading
and provided to the recording device such as the data
logger, item 7 to record and store the readings or a PLC,
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item 14. Once several different loads have been timed
accurately for a particular piece of equipment, the
proper formula for the factors necessary to convert power
consumption in kilowatts or electrical current amps to
tons per hour for a piece of equipment may be determined
as shown in figure 6 and figure 7. Once this formula has
been determined, any subsequent readings from the
equipment may be easily converted into tonnage per hour
utilizing the formula. Periodically (once per month)
additional material or belt cut loading rates can be
taken to confirm the regression formula. Experience has
shown that accuracy improves with actual material load
tests and if more than the recommended three tests are
made, a better regression formula will result. As with
belt scales, it is recommended that the no load setting
be checked daily after equipment has had a chance to warm
up. This procedure can also help to provide early warning
of possible equipment failure should a significant change
in "no load" figures be detected ( figure 10 and figure
12).
The system of the present invention as described
above was applied to conveyor systems in a variety of
quarry operations. The watt transducer and current
transducer measuring devices were attached to the three
wires of the three-phase electrical input to the motor
driving a conveyor belt of the quarry system. This motor
was fed by the local utility grid. The output of the
watt transducer and current measuring devices were
connected to the input of a Tonnage Analyzer data loggers
which measure kilowatts, AC current, pressue and
temperature (Figure 3 capable of monitoring 14 conveyors
or bucket elevators and expandable up to 42 input
signals).
The output from the data logger, item 7 was
connected to a suitable computer, item 9 utilizing a
standard interface port such as RS 232,item 8, USB and
DDE. The measurements for tonnage per hour were
calculated using a regression analysis function in a
suitable computer spreadsheet. The calibration of this
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system is illustrated in figure 6 and figure 7 which is a
graph of the amperage or power consumption of the motor
vs. tonnage per hour of the conveyor belt system. As
can be seen from figure 6, the motor in a no-load
situation draws approximately 20.4 amps and in figure 7
which shows the calibration graph for kilowatts to
Tonnage the "no load" reading is 12.5 kwatts. As the load
on the motor or the amount of material applied to the
conveyor system is increased, the amount of amps or
kilowatts drawn by the motor increases gradually until
the load on the motor is sufficient to provide a linear
relationship between power consumption and tonnage per
hour on the conveyor. Typically this will be on the order
of 10 percent of the rated capacity of the conveyor
system and well below the normal operating parameters of
the system. From the data measurements as shown on
figure 6 and 7 the regression analysis formula for this
particular setup was calculated. A number of test runs
were then conducted in which known loads of material were
placed on the conveyor system and the predicted tonnage
per hour output based on the regression analysis formula
compared to the actual tonnage per hour of the samples.
The results of this are shown in figures 6 and 7. As
clearly seen in figure 10, there is an excellent
correlation between the predicted and actual tonnage per
hour for this system using kilwatt measurements. Figure 9
shows the graph of actual kilwatt consumption for a
typical day. It is the actual readings taken from this
graph which forms the basis for the conversion to tonnage
as shown in figure 10. As an option, once the calibration
formula has been established as shown in figure 7, then
the graph in figure 9 can be set up to show live tonnage
readings as shown in Figure 13.
The same procedure applies to amperage conversion as
shown in figure 11, showing a typical Amperage graph and
figure 12 shows the spread sheet converting readings to
Tonnage. In Figures 8 and 8b we have tables showing the
summary of several days of data collection and results
compared to belt scale readings for the same days. In
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figure 8 we show the comparison between readings taken
with amperage versus kilowatts converted to tonnes. In
figure 8b we show the conversion using kilowatts as well
as the 'No-Load and Start-Up load' times which illustraes
the potential for production improvement if these times
could be reduced.
If the electrical power is supplied by a generator
and the power is not well balanced then only the watt
transducer method is recommended as the most accurate
measurement of the power consumed to relate to tonnage
per interval of time. In each case it is necessary to
isolate the readings of electrical power in kilowatts or
current in amperes which correspond to a "no-load"
situation on the equipment to ensure that the cumulative
data per period of time, only includes readings when the
equipment is running loaded. Likewise if frequent stop-
start cycles occur especially with loaded equipment then
these overload readings "Start-up surges" need to be
isolated and recorded separately, to ensure daily power
consumed as related to tonnage is only applied to
readings were there is an actual material load on the
equipment
It is very important to note that an essential
feature of an aspect of this invention is the recording
of these separate readings ie "no load" and "start up
surges" which provide valuable information on lost
productivity which can lead to large opportunities for
improvement. In the case of "Start-up surges", this
invention could help to extend the normal operating life
of the conveyor motor by providing a record of these
occurences. If they became too frequent then ways could
then be found to reduce these start-up surges with the
additional benefit of increased production.
While the above example is described in connection
with a conveyor system in a quarry operation, the present
invention is not so limited. In addition to quarry or
mine operations, conveyor systems in many processing
industries such as cement plants, pulp and paper mills
and processing plants for grain and other food stuffs,
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sand and gravel pits, etc. can also use the apparatus and
method of the present invention.
It should also be noted that in the portable format
using the data logger the same system can be applied to a
portable crushing plant with motors operated by hydraulic
systems. Instead of using a watt transducer, a pressue
transducer can be used with the ACR SmartReader Plus 7
model and the same procedure described for watts can be
applied to the pressure sensing device measuring psi used
by the motor at various operating levels.
A further aspect of this invention is the use of
this invention on a stacker conveyor. On a Starker
Conveyor, if they move up or down we need to add a
further measuring device to input the angle of operation
i.e. as the conveyor moves upward there is an added force
added to the components being measured. This may be
achieved using a digital inclinometer such as a US
Digital A21 or a Xbow Tilt Sensor model CXTA01 with RS235
outputs. With either of these angle measuring devices, a
signal can be fed to a PLC to provide data on the angle
above horizontal the conveyor is operating. The
calibration process described above is repeated for
differing loads at a minimum and maximum angle of
operation. A new regression formula is calaculated for
each change in angle and as the conveyor moves upward or
downward the tonnage moved will be adjusted accordingly.
With the watt transducer model another aspect of
this invention is the new ability to predict the maximum
full load capacity for each conveyor or bucket elevator
based on the motor's specification and the corresponding
tonnage per hour reading possible when the motor is
operated at its maximum designed kilowatt rating. In
other words, once the calibration formula has been
established, then the maximum kilowatt rating of the
conveyor or bucket elevator motor can provide a direct
conversion to tonnage the motor can be expected to move
at that kilowatt reading.
A further aspect of this invention is the use of the
output signal from the watt or current transducer as an
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input signal for automated systems to help adjust feed
rates by feeders to a crusher. If the feed rate is to
high, then the automated system may shut down a conveyor
feeding a crusher rather than just adjusting the feed
rate to provide a continous flow to the crusher. In the
case of a cone crusher, the best results will occur if
the crusher is kept full all the time and no start and
stops occur. Fewer start and stop occurences which will
increase motor life, improve accuracy of tonnage readings
and result in higher quality crushing of rock.
The present invention is applicable to any operation
where an apparatus or machinery is powered by an
electrical motor and where it is desired to measure the
tonnage output of the machinery such as a bucket or
stacker conveyor. Another important application of this
invention is to set up this system in parallel to an
existing belt scale application as a low cost method of
cross checking the tonnage readings being recorded by the
belt scale. Belt scales can lose accuracy if a rock falls
on the frame or material builds up around the frame or
the idlers become misaligned etc. In modern quarry and
mine sites where belt scale readings become the input
data for automation control setups, a means to insure
accurate data is being continously provided is more
critical and the present invention if installed in
parallel provides an early warning of any deviation in
readings, avoiding errors in batch and blending
processes. With use and improvements in this invention it
may be possible that this method could be the primary
system in the future providing a lower cost and
maintenance free system for accurate measurement of
tonnage of material
The apparatus and method of the present invention
provides an improved and faster method of measuring
weight in tons (tonnes) of material over a device or
removed by a piece of equipment at lower cost and with
the capability of showing these tonnage reports locally
or by telecommunications device to a remote location.
This method may be applied at several locations in an
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operation and will provide a new way to measure tonnage
and productivity through out the operation.
Finally as mentioned at the beginning, this
invention provides a new simplified method to compare
blast fragmentation results. In the Mining and Quarrying
Industries today all operators have a common goal to
increase productivity and lower overall operating costs.
Often it is easier to measure a localized improvement,
which sometimes can actually increase overall costs and
lower production rates at other parts of an operation.
What complicates this process is the multitude of
variables that occur in the transformation of solid rock
to a final rock size or series of sizes and shapes with
the least amount of waste. To further complicate the
overall picture is the ever-changing choice of products
and equipment advertised by manufacturers as ways to
lower costs and improve production. One of the greatest
challenges facing operators is finding ways to easily
measure productivity improvements at each step in an
operation to insure overall reduction in operating costs.
In industry today beginning with drilling and
blasting there are many methods currently used to measure
and compare results such as digital photo analysis of
blasted rock fragmentation, actual sieve analysis, time
studies to excavate a blast, just to mention a few. These
methods will give good results for parts of a blast but
not the entire blast and they are fairly complicated to
use. Then there are the variables of actual geology at
the site, which can vary from one location to the next.
When you get to the crushing and screening of the rock, a
whole new series of variables can influence the results
such as choice of crusher, actual settings of crushers
and screens which will alter the results as the rock is
processed. With all these variables it will always be
difficult to find a method which gives an actual overall
comparison of results. However with today's technology
and computer assisted measuring devices it is possible to
build a model, which gives a clear picture on the actual
energy consumption and production rates at each key step
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in the operation. Using this approach it has been found
that such a model can be used to compare results of
blasts and get a good correlation at the primary and
secondary crushers to compare production rates and final
split in low end and high quality crushed rock products.
In the simplest terms the process described
herein is a new way to achieve this overall goal of
reducing costs by comparing measurements of energy costs
for explosives with energy consumption in kilowatts to
operate equipment to process the rock. These measurements
when taken at key steps in the operation combined with
production rates will give a surprisingly clear picture
of the overall productivity and total operating costs.
In the case of mining and quarrying, where drilling
and blasting are the first stage in the process to break
rock for further processing, there is a need for a low
cost and fast method to optimize results from drilling
and blasting to maximize production in the crushing and
screening stages in the operation. To do this a new
process has been developed using the apparatus of the
present invention.
figure 2.
The apparatus of the present invention with
it's multi channel data loggers is a new computerized
process to measure tonnage and productivity in a Mine,
Quarry or Sand pit operation combining several measuring
device readings to establish a base line. This multi-
functional process uses power or pressure transducers to
input information from motors if data from belt scales or
motor metering devices is not already available. With
this process it is now possible to combine live conveyor
tonnage productivity at key steps in the operation, with
live power consumption readings at the Primary and
Secondary Crushers using watt transducers. These
measurements can then be used to compare individual
blasts to optimize blasting results thereby achieving
improved production at the primary and secondary crushing
and screening stages of the mine or quarry. In other
words, changes made at the drilling and blasting stage
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can be evaluated by comparing production rates with
actual tonnages of final rock products produced versus
percentage of lower end products such as fines or pit run
materials.
One of the keys to the success of this process
is the ability to easily identify loss of production at
each step in the operation, which shows up as "no load
and start-up" time. Reducing this "no load and start-up"
time, which is often a direct result of oversize rock,
can often be achieved by spending more money on drilling
and blasting to reduce oversize. In this new process
added cost at the drilling and blasting stage can be
compared to downstream increase in production with a
lowering of overall operating cost.
At quarries and mines blasted rock is the first
step in the production process. The input data used by
the apparatus of the present invention begins with power
consumption readings from the primary crusher (Figure
15). If a rock breaker is used to break up oversize at
the primary then a pressure transducer operating off this
motor can also be monitored to show power consumed and
possible down time at this stage. The use of the pressure
transducer will help to separate time waiting for trucks
to dump at the crusher versus time used to break up
oversize rock with the hydraulic breaker.
After the primary crusher all major conveyor
motors operating belts at each stage in processing are
then monitored with the apparatus of the present
invention. If belt scales are installed these readings if
available as digital readings can be used as an alternate
source; however it is important belt scales are zero
checked each day to insure consistent readings. All of
these readings form the basis of this new process to
measure productivity and will also provide a new
simplified method to compare blasting fragmentation
results from similar blasts.
Each blast is monitored showing the total
energy, above a no load level used to crush rock at the
Primary crusher, Figure 14 and 15. Moving downstream all
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main conveyors moving crushed or screened rock are
monitored for daily production rates and total tonnage
produced for each final rock product size. At each
conveyor we also have energy consumption figures in
average kilowatts used during a recording period to
compare with tonnage rates, figure 10.
There are many variables which influence the
overall production process. The measurements we are
taking will provide clear indications of trends and will
generate repeatable and accurate results. For the
conveyors and the primary crusher the zeroing function
used with power transducers will filter out most outside
variables, which may otherwise distort readings. With
use, other variables will be identified, and ways can
then be established to filter out or include this new
data to better refine the overall process.
Using tonnage production rates and power
consumption rates in kilowatts at crushers will provide a
new way to compare blasting results and show the impact
on the full process when changes are made at the drilling
and blasting stage. At many operations today the drilling
and blasting stage is often under pressure to reduce
costs, as are other parts of the operation. Drilling and
blasting is one of the easiest areas to measure costs and
lowering cost at this stage often results in larger
fragmentation where productivity is much more difficult
to measure. The apparatus of the present invention will
help to insure any changes occurring in one area can be
easily measured throughout the production process to
confirm if an overall improvement has been achieved. With
continual improvements by industry, with new products for
blasting and new equipment for crushing and screening it
is important to be able to evaluate the impact of these
new products or equipment on the existing production
process. The multi functional apparatus of the present
invention will insure all areas of the plant work at
optimal levels and any benefits from new products or
equipment will be measurable to see their impact on the
production cycle.
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CA 02387444 2002-05-24
JJ-11 384-1CA
This system becomes a useful tool to help
operators to see their live production rates
(tonnage/hour), daily production in tonnes (tons) and the
motor monitoring function will provide early warning of
possible overload conditions. In Mines and Quarries, the
combined production and energy consumption figures become
a new method to compare blasting results. For the manager
this process can be used to determine maximum production
rates at each stage in the process. For planning purposes
the apparatus of the present invention can be used to
establish the time and tonnes (tons) of blasted rock
required to produce a future order for a specific stone
size. Similarly a breakdown of other product sizes
produced will be shown to help management decide the best
split of products to produce, which will bring the
highest margin.
The apparatus and process of the present
invention is a new process using advanced computer
automation control devices to collect and analyze data
but keep output data in a format that is easy to read and
interpret. The overall process can be further expanded
to include additional input data such as loader and truck
scale readings. This additional information may be useful
in comparing blasting results but still needs further
research. The main purpose of this present process is to
help industry to better understand the overall process
and help integrate all operations to optimize overall
productivity.
Although various preferred embodiments of the
present invention have been described herein in detail,
it will be appreciated by those skilled in the art, that
variations may be made thereto without departing from the
spirit of the invention or the scope of the appended
claims.
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