SK567789A3 - Method of increasing accuracy or reliability when measuring one or more characteristics of bulk material obtained by measuring devices - Google Patents

Abstract

This invention concerns a method and apparatus for auditing the means of measuring one or more variables which affect the accuracy or the reliability of the results obtained by devices used to measure particular characteristics of a bulk material, especially during handling and processing, and when said characteristics are measured on an aliquot extracted from said bulk material, a method and an apparatus for concurrently auditing one or more variables affecting the accuracy or reliability of the means for extracting an aliquot of said bulk material.

Description

Technical field

The invention relates to a method for increasing the accuracy or reliability of the measurement of at least one property of bulk bulk material by measuring devices.

BACKGROUND OF THE INVENTION

For bulk bulk materials such as bauxite, elemental sulfur, phosphates, gypsum, limestone, cement, iron ore, pelletized iron ore, maize, wheat and other grains, sugar, coal, lignite, peat, anthracite, waste, sewage sludge, wood chips, bark and paper are generally measured for different characteristics, particularly during transport or processing, either directly or indirectly on an aliquot sample taken to accurately contain each variable component present in the total amount of the material in the same proportions and in the same physical and chemical condition; in which it is present in the total amount of this material. The value of such materials in the United States is enormous. For example, in the group of forest products included in Standard Industrial Class 26, the total value of deliveries in 2005 was approx. 1986 approximately $ 108 billion. Of this amount, $ 4.1 billion was sold to pulp mills, $ 42 billion to paper and cardboard factories, $ 23 billion to newsprint manufacturers, $ 14 billion to corrugated and straight cardboard cartons, and $ 11 billion to sanitary paper products and $ 3 billion for food sanitary packaging. Coal is another bulk material for which various characteristics are regularly measured, and in 1986 the forecast for coal mining and processing in the United States was approximately $ 23 billion.

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Of other bulk materials, nitrogen and phosphate fertilizers account for about $ 9 billion a year, for metals of the first smelting for 50 to 60%

billion, and about $ 12 billion for inorganic chemicals. In 1986, the US produced cement for about $ 4 billion.

However, there are major errors in the handling and processing of some of these bulk bulk materials when taking aliquots to measure these properties, particularly in terms of mass quantities of bulk bulk materials, but also in determining other characteristics of these products.

For example, coal is mined in the United States in about 5,000 detectors operated by approximately 3,000 companies. Approximately 85% of the total amount of coal extracted in the United States is consumed annually by electricity companies serving the public for about $ 22.9 billion. Coal reserves in these electrical businesses are continuously around 163 million tons, with a nominal value of $ 5.5 billion.

These electricity undertakings write off up to 5% of stocks annually due to their inability to reconcile the amount of coal purchased with the amount of coal burned. This corresponds to an annual depreciation of this product alone of $ 273 million. Since coal is practically not perishable within the usual time frame considered in the coal trade, these losses do not in most cases constitute natural losses but rather inaccuracies in weighing, sampling and analysis. In general, weighing and sampling errors increase as the amount of material to be weighed or from which the sample is taken decreases. Experience has shown a tendency to increase because material handling operations are performed at less than full capacity.

Costs are also extended to areas other than just stock correction. For example, inaccuracies resulting in an overestimation of actual inventories must be compensated by providing the extra amount needed to meet the necessary need. The costs of buying, storing, interest and insurance are very real, though precisely incalculable in the absence of more accurate figures. A further increase in expenditure is linked to a lack of more accurate and timely quality information.

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Indeed, the impact of a forced reduction in equipment performance, including the purchase of third-party energy, losses associated with less than ideal energy supply, and operations with coal of better quality than actually complies with air quality regulations can be mentioned. As already mentioned. these economic losses cannot be easily estimated due to lack of information and timely information; but they are considerable. The same problems arise in the Ilyry of the bulk industry processing bulk materials, where nanotubes far exceed coal-related amounts.

At the end stations, where bulk bulk materials are passing through both the export and import markets, there is a considerable need for sampling = 'embossing'. The United States produced approximately $ 4 billion in 1986 for csrre-Ĺ = imported for approximately $ 300 million. The value of shipments of metals and minerals in Classes 10 and 14 of the Standard Industrial Classifications, excluding fuel, was $ 23 billion in 1986. Imports reached 3.2 dollars. The coal industry exported 88 million tons of coal worth onihscQisnej to $ 3.5 billion.

SUMMARY OF THE INVENTION

These drawbacks are overcome by the inventions of a method for increasing the accuracy or the ability to measure at least one property of bulk bulk material measured by means of devices which, in essence, are parallel to the aforementioned rrera-fr. at least one variable that is independent of the measurements made by said measuring devices but directly or indirectly is measured, is measured, the measured value of this variable being compared to a pertinent reference variable and the results of the measurement of the bulk bulk mae-a- properties are adjusted accordingly , taking into account the deviation of the measured variable veíiär, * c of the reference quantity.

According to a further feature of the invention, a bulk sample is physically taken from bulk bulk material, the properties of the sample are measured, variable variables are measured, measured variable values are compared to a reference variable, and the measurement results are corrected accordingly. The sample is preferably taken as a small current.

The invention makes it possible to increase the accuracy of measurements so that the results are not influenced by variables which can affect the accuracy and reliability of said measuring devices.

The invention is preferably carried out in a device for improved control of operations by feedback at preselected limits over control provided by the level control in the container, a calibrated chute or sensors to signal the passage and material flow, and to signal conditions outside selected boundaries which may require operator intervention to correct or adjust.

Overview of drawings in drawings

The invention will be explained in more detail in the following description with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic of the application of the invention for the transport and handling of coal from reception in the discharge wagon from the eaki to its removal from the landfill pile for supply to the burner; FIG. 2 shows a schematic of the application of the invention in the progressive movement of coal by a mechanical sampling system, a cell, an in-line analyzer, a weight feed conveyor and a pulverizer, and hence to the burner.

Fig. 3 is an enlarged detail of a coal processing scheme in the typical mechanical sampling systems shown in FIG. 1 and 2, a

I

Vili obr. 4 is a schematic of computer software and peripherals used in the present invention to receive, store, and analyze data obtained from individual sensors used in the system to signal, record, and maintain

V 389/94 B database of conditions for operation, malfunction and failure, and for local and remote reporting of bulk material status, receipts, use and inventory, video monitors and printed recordings, and for comparison with major video computers.

DETAILED DESCRIPTION OF THE INVENTION

Although the invention has been described with particular reference to use in coal handling in power plant equipment, it is equally applicable to other bulk bulk materials. All components of the device for carrying out the invention, except for a particular installation, are components commercially available on the market today.

In FIG. 1 shows an unloading device comprising a hopper 10 on a rail track. The coal falls from the hopper 10 into the crusher and from there onto a belt conveyor 12 running through the belt weigher 13 and thereby into the belt assembly 14 a mechanical sampling. Coal not collected in the mechanical sampling system 14 is entrained up by the belt conveyor 15 and is then spilled onto the stock heap 16. The rail hopper 10 is typically a coarse sieve represented by a bar grate with apertures of approximately 0, 09 m ² so that excessive pieces and large lumps of frozen coal do not get trapped in the system. Such pieces are broken up either by hand or in special crushing equipment. Although, for the sake of simplicity of explanation of the invention, the hopper 10 illustrates how it discharges coal directly into the shredder 11, in practice the coal stream from the hopper 10 is controlled by means of metering conveyors.

Typically, auxiliary equipment around power stations is designed to process coal with a maximum size of 5 cm. The main purpose of the shredder 11 is to reduce the maximum size of the coal so as to comply with this operating requirement.

The belt weight 13 is an officially verified commercial weight. This means that the weights found on it serve the purpose of paying to the coal supplier. On the crusher 11 a sensor 18 is placed on a belt weigher 13, a sensor 19 on a pte assembly 14, a sensor 20 on a conveyor belt 12 and a sensor 21 on a conveyor belt 15. These sensors include one or more specific sensors. as in —p. - Ιγ r Γ * · «

In 389/94 B, the input and output power lines 22-22 are described and connected to the appropriate recording and tracking devices shown in FIG. 4. Coal from the storage heap 16 can be removed as required by a conveyor 23.

The coal from the conveyor 23 of FIG. 2 is poured onto a conveyor 24, where it passes again through a further belt weigher 25. This belt weigher 25 is generally an officially verified weight, but is not used as commercial. Instead, it is used to determine the mass amount of coal to be burned. The coal falls from the end of the conveyor 24 into the bunker 26, with an appropriate amount being withdrawn in the mechanical sampling system 27, which is typically a mechanical sampling system, usually identical to the mechanical sampling system 14. The coal then passes through the in-line analyzer 28, through the weighing conveyor 29 and the pulverizer 30 to the burner 31.1 there are provided sensors, namely the sensor 32 on the conveyor 23, the sensor 33 on the belt weigher 25, the sensor 34 on the belt conveyor 24, the sensor 35 on the system 27. for mechanical sampling, sensor 36 on bunker 26, sensor 27 on embedded analyzer 28, sensor 38 on weighing conveyor 29, and sensor 39 on crusher 30. These sensors include one or more specific sensors as described below and are coupled input and output power lines 22a-22a with respective recording and tracking devices shown in FIG. 4th

Coal trading is traditionally conducted on an out-of-date (wet) basis. This practice is the source of many discussions between buyer and seller.

Moisture component is subject to loss of runoff and evaporation and vice versa is increased by precipitation in the form of rain or snow. In the northern regions, frozen coal is a constant problem. Often a blockage occurs when wet, non-freezing coal comes into contact with metal surfaces whose temperature is below freezing. sensors

17,18, 19, 33, 35, 37 and 38 are used to monitor and continuously record, in real time data and time stamps, ambient and metal surface temperatures of the crusher H, belt scales 13, assemblies 14 pte mechanical M sampling the belt weigher 25, the mechanical sampling system 27, the bunker 26, the in-line analyzer 28, the weighing conveyor 29, as well as the relative humidity in the crusher 11 and the mechanical sampling system 14. These data

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verify temperature and humidity conditions <pce. reliable and accurate operation

V 389/94 B of the sampling and weighing systems and make it possible to raise an alarm under conditions that could cause work problems or incorrect operation of the equipment.

Bulk bulk materials such as coal are occasionally contaminated with foreign materials that may damage the equipment. Coal is a precaution because it can contain anything from detonators to broken parts of railcars. In coal handling equipment, magnetic separators are provided, as close as possible to the beginning of the handling process, to protect the equipment from iron debris. Despite these measures, such foreign materials occasionally damage the moving mechanisms. Sensors 17, 18, 19, 33, 35, 37 and 38 serve to monitor and continuously record, in real time data and time stamps, the rate and type of vibration and noise and its composition at the shredder 11, belt weigher 13, assembly 14 for mechanical sampling, belt weight 25,, ΛλΑ.

of the mechanical sampling system 27 and at the crusher 30 to verify the operating conditions for reliable accurate operation of the sampling and weighing systems. This creates additional possibilities for detecting excessive or unusual conditions that could adversely affect aliquot or sample collection and weighing, and also allows the alarm to be set to conditions that indicate operational problems with possible equipment malfunction. There is no exact boundary between the audible frequencies and the mechanical vibrations, but in general the mechanical vibrations, coupled with the heavy machinery, are below the audible frequencies; therefore, both audible frequencies and mechanical vibrations are monitored and continuously recorded and compared with the appropriate reference values. This also makes it possible to detect the neglect of operators in the event that the continuous flow of coal is retained.

The hammer crusher product is greatly influenced by the peripheral speed of the hammers. The peripheral speed is dependent on the rotation speed. The load, higher voltage and power or current drawn by the crusher motor all affect the rotation speed. The motor temperature is also affected by load and voltage. Both vibration and noise level are affected by the rotation speed. Sensors 17, 19 and 35 serve for monitoring and continuous recording, in real time by data and time stamps, rotational speed as well as the magnitude and frequency of vibrations and sounds coming from the crusher 11 and

V 389/94 B from crushers which are part of assemblies 14 and 27 for mechanical sampling. These sampling systems are described in detail below with reference to FIG. Third

In addition, other variables are variables, i. The voltage, current, power and temperature of the motor, recorded by means of sensors 17, 19 and 35 in real time by data and time stamps to verify the operating conditions for the reliable operation of these crushers. This provides an additional possibility to detect excessive or unusual conditions that could adversely affect sampling and weighing, and allows the alarm to be set for conditions indicating operational problems and possibly equipment malfunction. This also provides the possibility of diagnosing the faults on the device.

In FIG. 3, part of the sampling device 14 and 17 is shown in detail. A typical two-stage mechanical sampling system is illustrated schematically. It consists of a primary cutting mechanism 40, a primary feeding conveyor 41, a sample crusher 42, a secondary cutting mechanism 43, a collecting container 44-44 for a sample, a circular conveyor 45, and a weight 46 for a sample. Appropriate chutes connect the components with mechanisms and direct the movement of the coal through the sampling system. Three-stage systems are also quite common, which include an additional degree of disruption using a tertiary cutting mechanism.

The handling properties of bulk bulk materials vary according to the particle size distribution, moisture content and relative amount of impurities. Coal is one of the most difficult to process of all bulk bulk materials. This situation is exacerbated by incremental crushing and disruption within the sampling system, which changes the material handling properties and reduces the rate of movement of the crushed sample to such an extent that friction, adhesion and cohesive forces tend to dampen the inertia and gravitational forces that keep coal moving.

Clogging, containment, irregular and intermittent coal movement are potentially serious sources of error on the sampled sample. When such conditions occur, sampling systems often fail. The operator must then punch the chutes, cutting mechanisms and crushers with heavy tubes and sledgehammers to restore coal movement. Such failures may permanently adversely affect the operation of the sampling system.

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Sensors 47, 48, 49, 50, 51, 52, 53 and 54 are for monitoring and continuous

J? · ____ recording, in real time data and time stamps, metal surface temperatures, vibrations and vibrating patterns, sounds and sound diagrams on connecting chute trays, on covers of individual sub-mechanisms, at a circular conveyor 45 and at a weight 46 for samples, to substantiate and verification of operating conditions for reliable and accurate sampling. This surveillance allows the alarm devices to be set to conditions that indicate operational problems and possible malfunctions or malfunctions of the equipment, and also provide the possibility of diagnosis to correct errors and malfunction of the equipment. These sensors include one or more specific sensors, as described below, and are connected by input and output power lines 55-55 to the appropriate recording and monitoring devices shown in FIG. 4th

There are two basic methodologies commonly used to collect aliquots of bulk bulk materials on a time and mass basis. For both types of sampling, national and international standards prescribe the minimum number and minimum weight of samples required, which are proportional to the weight of the whole quantity or of the whole lot to be represented by an aliquot.

When taking a time-based sample, the sample shall be taken at equal time intervals. In order to maintain the same ratio of the quantity of the individual variable components in the sample as that of the whole quantity, the cutting mechanisms for separating the sample taking or draining the sample must move at a constant rate equal to each sample.

When sampling on a mass basis, samples are taken in uniformly defined mass quantities and the speed of the cutting mechanisms must be changed in proportion to the variations in the rate of movement of the coal in order to maintain the same proportions of individual components in the sample.

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Serious errors may occur when sampling on both time and weight basis if shifts of the cutting mechanism occur synchronously with linear changes in quality over time or weight, or if shifts of the secondary or tertiary cutting mechanism occur synchronously with previous cutting mechanisms in the sample. system.

Linear quality changes, based on time or weight, are often related to changes in coal velocity, which again may reflect the limited capacity of the material transport system associated with the changing handling characteristics of bulk bulk material. The crushers also cause linear quality changes, based on time or weight, which can be attributed to the fact that the lighter crushable material is crushed first.

Thus, to verify operating conditions - accurate and reliable time and weight based sampling, sensors 47, 52 and 56 are provided to detect the number of shifts of the primary cutting mechanism 40 and the secondary cutting mechanism 43 and to measure the primary feed / pásuβ belt speed. conveyor 41 as well as for measuring and recording, in real time time and data stamps, times at which the cutting mechanism is shifted, the length of the feed cycle, the speed of the sample cutting mechanism at each shift, and to determine if the cutting mechanisms are operating synchronously. In addition, this surveillance allows the alarm device to be set to conditions that indicate operational problems and possibly malfunction of the device and, of course, the possibility of diagnosing the problem as soon as they occur.

Sensors 18 and 33 are used to monitor and continuously record, real-time data and timestamps, coal velocity, voltage and frequency of electrical current supplied, ambient temperature, vibration, and run time of the belt scales 13 and 25, and to verify coal velocity to the sampling systems 14 and 27 and to control the synchronization of changes in the coal movement with the shifts of the cutting mechanisms.

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The sensors 20, 21 in FIG. 1, 32 and 34 in FIG. 2 and 56 in FIG. 3 are used to monitor and continuously record, in real time, data and timestamps, conveyor belt speeds, voltage, current (or power) to belt conveyor motors or hydraulic auxiliary motors to detect faulty conditions on conveyors 12, 15 , 23, 24 and 4Ί.

All conveyors of modern bulk material handling systems are coupled to each other to prevent any conveyor in the system from operating in front of another conveyor that is not currently in service. For this reason, the sensors monitoring the status of the control devices are an important alternative to the above-mentioned sensors recording the conveyor speed, voltage, etc. information.

Dynamic weighing of the material in motion during transport brings many variables that can affect weighing accuracy. These also include the flexibility and tension of the belt. Temperature also affects analog and digital electrical equipment. Many existing belt scales use mechanical devices to measure belt movement (speed) and load as well as integrating belt speed with load. More recent technologies use electromechanical and electronic devices to measure belt speed and load size as well as integrate belt speed with load. The accuracy of these mechanisms is vulnerable to radio frequency interference (RFI) and electromagnetic interference (EMI) as well as voltage and frequency fluctuations. Both mechanical and electronic scales are affected by belt overhangs between adjacent guide rollers and vibrations, which may be caused, for example, by belt splicing or near-running devices, i.e. sampling systems and crushers.

The accuracy of the belt weigher is also influenced by the load height. For commercial weighing scales, the load is limited by the provisions set out in the National Bureau of Standards Handbook 44 to a range of 35 to 100% of the nominal capacity. Alarm devices must be provided to signal traffic above these limits.

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Sensors 18 and 33 are used to monitor and continuously record, in real time data and time stamps, the rate of coal advance, voltage and frequency of electrical current supplied, ambient temperature, vibration, and operation times of the belt weighers 13 and 25. This information with similar information for the respective conveyors 12 and 24 are important for verifying the validity of the weighing without adversely affecting the factors thus measured.

The value has two dimensions, quantity (weight or number) and quality (valuable characteristics or components). The Company requires, through laws and regulations, that weighing for the purpose of payment be carried out on an officially certified balance.

Sampling bulk bulk materials is a complex, challenging task for which the need for accuracy, correctness, and reliability generally has not achieved broad company recognition, as in weighing. As a result, no similar statutory or verification rules apply to the sampling. However, there are national and international voluntarily agreed sampling standards that are widely used in trade and are mentioned in contracts and agreements.

The introduction of a parser puts the processing and handling of bulk bulk materials at the threshold of a new era in which the state of income, inventory, and use of the collected material can be reported in real time by the content of valuable components or special parameters as well as more conventional conventional mass units such as tons or pounds. Typically, for example, electricity utilities serving the public have so far refused to keep records of receipts, stocks and use of coal taken, expressed in terms of calorific value in British thermal units (BTU), which is a valuable feature of coal with which they actually have something to do. prompt information on calorific value. The introduction of embedded analyzers capable of providing this information in real time eliminates this problem. The currently available in-line analyzers utilize X-ray fluorescence, microwave moisture analysis, nuclear magnetic resonance, gamma ray analysis and analysis.

In 389/94 B neutrons continuously activated by gamma rays, and continuous calorimetry. This makes it possible to determine the combustible components of coal in real time.

Depending on where the downstream analyzer is located, the sensor 37 located on the downstream analyzer 28 receives real-time analytical data regarding the currently received, stored, and for use of the currently collected bulk material, which data is then transferred to the database residing on the computer and the associated operating software (Software), as described in detail below with reference to FIG. 4th

The factors discussed above go beyond those in the laws and regulations that may adversely affect the accuracy and reliability of certified scales, sampling systems and in-line analyzers. By measuring and continuously recording these factors in real time, the accuracy of the weighing can be verified to a greater extent than previously possible. By similarly guarding machine sampling and in-line analyzers, it is possible to increase compliance with relevant sampling and testing standards, accuracy, accuracy and reliability of bulk bulk material sampling and analysis to virtually the same level of verification as is achieved with certified weights. In combination with verified weights, such sampling can effectively provide instantaneous valuable results having a verified status.

In FIG. 4 shows a computer 57 equipped with a disk drive assembly 58, a video terminal 59, one or more printers and connected by an input and output power line 61 to the respective lines shown in FIG. 1 to 3, from sensors. Also shown schematically are a modulator-demodulator 62, a telephone line 63 to the central office 64, and a microwave link 65 to the central repair shop 66. The computer 57 is controlled by its own operating software (Software) common to the individual sensors in the system via multiple analog and digital input - output channels that modify the input signals. The computer 57 is equipped with an electronic clock - calendar, powered discs for continuous recording of the data sensed by the sensors and the necessary interfaces for the modulator - demodulator, printer with video terminal keypad.

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The computer software provides many services. Converts sensor signals to real, world-wide units, if necessary, directs the continuous recording of sensor data to a database maintained on a system of 58 powered drives with date and time stamps from an internal electronic clock with calendar, analyzing sensor data by comparing to pre-selected parameters , controls the sampling operation in synchronization and activates the optical and audible alarm for any conditions beyond preselected limits or requiring operator attention or intervention.

Appropriate parameters may be selected as appropriate reference values for comparing both the data obtained from the bulk bulk material measurement device and the variables measured in parallel with the bulk bulk material measurement. Such parameters include, for example, contract, equipment and operation specifications, operating and material standards, purchasing and takeover specifications, legal boundaries, and empirical and experience boundaries.

Operational Equipment (Software) also checks whether bulk bulk material is received within prescribed qualitative and quantitative limits, and recalculates receipts, inventory, and material usage for world-wide weight units, valuable components, valuable properties, and monetary units. Operating Equipment (Software) provides the necessary services for entering biographical data through the keyboard and protects the security of access to various operating equipment data (Software) through predetermined priority levels. The operating software (Software) provides interrupt, failure, status, operation, and diagnostic messages, both locally and at remote terminals in the main office and repair shop. The software also provides inputs and outputs to other computers.

The machinery of this invention is locally specific and must be adapted to the specific needs of the workplace. It is desirable that the computer program instruction code be a modular input code to facilitate this adaptation. Such computer programs can be qualified

In 389/94 B workers - programmers, knowledgeable compiling the composition or higher computer languages, without great difficulty compile.

While the invention has been described in its preferred embodiment, it should be noted that it can be subjected to various changes without departing from its scope and invention.

Claims (3)

PATENT CLAIMS A method for increasing the accuracy or reliability of measurement of at least one property of bulk bulk material by measuring devices, characterized in that at least one variable that is independent of the measurements made by said measuring devices but directly or indirectly affects the measurement , the measured value of this variable is compared with the respective reference quantity and the results of the measurement of the bulk bulk material properties are adjusted taking into account the deviation of the measured variable from the reference quantity. Method according to claim 1, characterized in that a bulk material is taken from the bulk bulk material, the properties of the sample are measured, the variables are measured simultaneously, the measured variables are compared with a reference variable and the measurement results are corrected accordingly. Method according to claim 2, characterized in that the sample is taken in the form of a small stream.