CA2387444A1 - Method for assessing the operation of a conveyor apparatus - Google Patents
Method for assessing the operation of a conveyor apparatus Download PDFInfo
- Publication number
- CA2387444A1 CA2387444A1 CA 2387444 CA2387444A CA2387444A1 CA 2387444 A1 CA2387444 A1 CA 2387444A1 CA 2387444 CA2387444 CA 2387444 CA 2387444 A CA2387444 A CA 2387444A CA 2387444 A1 CA2387444 A1 CA 2387444A1
- Authority
- CA
- Canada
- Prior art keywords
- motor
- conveyor
- tonnage
- load
- readings
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G11/00—Apparatus for weighing a continuous stream of material during flow; Conveyor belt weighers
- G01G11/04—Apparatus for weighing a continuous stream of material during flow; Conveyor belt weighers having electrical weight-sensitive devices
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Control Of Conveyors (AREA)
Abstract
The present invention is directed to an apparatus and method for measuring the weight of material such as rock, earth, wood, grain, gravel, sand, ore, cement etc.
being processed or moved by an apparatus such as a conveyor 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 calibration formula for converting the power consumption of the motor to tons per minute of raw material processed by the apparatus.
being processed or moved by an apparatus such as a conveyor 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 calibration formula for converting the power consumption of the motor to tons per minute of raw material processed by the apparatus.
Description
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.
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 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 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;
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.
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 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 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;
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;
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 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.
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, _ g -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 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 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, 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 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 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 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 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 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.
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.
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;
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 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.
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, _ g -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 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 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, 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 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 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 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 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 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.
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.
Claims (4)
1. ~An apparatus for measuring the weight of material being processed or moved by a material moving apparatus driven by an electrical motor, the apparatus comprising a means for measuring the electrical energy consumed by the motor driving the material moving apparatus during operation of the material moving apparatus and a calibration formula for converting the power consumption of the motor to tonnage per hour of raw material being processed by the apparatus.
2. ~An apparatus according to claim 1 wherein the material moving apparatus is a conveyor.
3. ~A method for measuring the weight of material being processed or moved by a material moving apparatus driven by an electrical motor, the method comprising measuring the electrical energy consumed by the motor driving the material moving apparatus during operation of the apparatus and utilizing a calibration formula to convert the amount of electrical energy consumed by the motor to tonnage per hour of raw material processed by the material moving apparatus.
4. ~A method according to claim 3 wherein the material moving apparatus is a conveyor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2387444 CA2387444A1 (en) | 2002-05-24 | 2002-05-24 | Method for assessing the operation of a conveyor apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2387444 CA2387444A1 (en) | 2002-05-24 | 2002-05-24 | Method for assessing the operation of a conveyor apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2387444A1 true CA2387444A1 (en) | 2003-11-24 |
Family
ID=29783799
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2387444 Pending CA2387444A1 (en) | 2002-05-24 | 2002-05-24 | Method for assessing the operation of a conveyor apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2387444A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10024708B2 (en) | 2015-05-22 | 2018-07-17 | Caterpillar Paving Products Inc. | Cold planer yield measurement system |
-
2002
- 2002-05-24 CA CA 2387444 patent/CA2387444A1/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10024708B2 (en) | 2015-05-22 | 2018-07-17 | Caterpillar Paving Products Inc. | Cold planer yield measurement system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7193162B2 (en) | Method for assessing the operation of a conveying apparatus | |
| CN101266160B (en) | Continuous dynamic intelligent metering mechanism | |
| CN101419239A (en) | Full automatic on-line sampling inspection system | |
| US20230009484A1 (en) | Rock hardness measurement | |
| US20240024891A1 (en) | Rock processing system with at least two value grain grading curves and automated operation dependent on the grading curve discharges | |
| CA2440771A1 (en) | System for collecting information | |
| CA2460650C (en) | Method for assessing the operation of a conveying apparatus | |
| CA2387444A1 (en) | Method for assessing the operation of a conveyor apparatus | |
| US4882927A (en) | Method and apparatus for auditing means used for measuring characteristics of a bulk material | |
| CN215140542U (en) | Self-adaptive ball feeding system of ball mill | |
| CN212379243U (en) | Device for on-line detecting sintering fuel granularity | |
| Tosun et al. | Development of a model estimating energy consumption values of primary and secondary crushers | |
| Quist et al. | The effect of liner wear on gyratory crushing–a DEM case study | |
| US5054327A (en) | Apparatus for auditing means used for measuring an aliquot from a bulk material for measurement of one or more characteristics of said bulk material | |
| CA2361973A1 (en) | Method for assessing the operation of a conveyor apparatus | |
| Hulthén et al. | Algorithm for dynamic cone crusher control | |
| Barratt et al. | Testing for autogenous and semiautogenous grinding: A designer’s point of view | |
| CN103612889A (en) | Automatic speed regulating and controlling method of coal mine tape machine conveying system | |
| CN87108168A (en) | A kind of method of controlling grinding particle size | |
| McClintock | Validation of methodologies for sizing a high pressure grinding roll | |
| de Haas et al. | Magosense: The innovative real-time mill monitor for the mining industry | |
| CN113617509B (en) | Automatic detection and compensation device and method for wear loss of lining plate of cone crusher | |
| CN1069336A (en) | Calibration device for elctronic belt balance | |
| US20240238798A1 (en) | Rock processing machine with wear assessment and qualitative evaluation of the wear assessment | |
| US20240024888A1 (en) | Rock processing apparatus with improved planning of the location of a material feed within a material buffer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead | ||
| FZDC | Correction of dead application (reinstatement) |