Patent Application
20240157373
The invention relates to a system and process for monitoring wear, particularly a system and process for technical maintenance based on dynamic monitoring of components of a grinding or rolling mill or other crushing device. In particular, the invention relates to a system and process for monitoring wear of a surface for grinding rolls, particularly roll profiles in fine grinding mils. Furthermore, the invention relates to a grinding mil with such a system.
Grinding mills such as mils or grinders frequently use cylindrical rolls or roll pairs for infeeding and crushing of a grinding or crushing material. Due to the required crushing effect of grinding rolls, these are generally provided with a hard surface or are cast and surface-hardened up to a depth of 10 mm, for example. Below the hard surface, the material of the rolls is relatively softer or tends towards more rapid wear, which can lead to possible damage of the entire roll and therefore failure of the grinding function. Therefore, it is advantageous to monitor the wear of the components of a grinding mil, particularly the surfaces of the rolls, periodically or continuously, as this enables the timely implementation of maintenance work and forecasting of the anticipated remaining service life of the components and therefore reliable maintenance of the grinding mils.
Conventional grinding mils exhibit a roll stand as a crushing machine, in which the grinding material is broken down and communited between rotating rolls. This construction of a grinding mill is currently the most widespread in industrial cereal mils. Grinding in a modern mill comprises two processes which are typically repeated multiple times: crushing and screening. The roll stand performs the grinding. In this case, the endosperm is removed from the bran in several processes. The mixture obtained as a result is directed onto a plane sitter for separation. The large particles which have not yet been crushed into flour are directed back to the roll stand by pneumatics or mechanical transport methods. A pass through the roll stand and plane sifter is known as a passage. In rough-grinding the grains are broken up by corrugated rolls. For breaking down, smooth rolls are used, by which the flour and bran are mutually separated. In full grinding, the lost particles of flour are separated out from the bran. The grain goes through eight to twelve passages before the flour is removed from the bran. In a closed housing, the grinding material, for example, the cereal, is dropped into the top of the roll stand. There, a feed roll infeeds it to the grinding gap while ensuring a steady volume flow. This grinding gap is formed by two rolls arranged horizontally or diagonally parallel that counter-rotate (like gear wheels). Various typically-adjustable parameters are decisive: (i) gap between the rolls (roll gap), (ii) differential speed (leading for corrugated rolls 1: 2.5 and for smooth rolls 1: 1.25), (ii) number of flutes, (iv) flute angle (spiral), and (v) mutual position of the flutes (ridge:ridge, ridge:blade, blade:blade, blade:ridge).
In grinding mills, the infeed devices and the rolls are arranged in such a way that advantageously the pressure on the work surfaces of the rolls is as uniform as possible.
Traditionally, the condition of the components of a grinding mill, particularly grinding rolls is monitored by a person skilled in the art monitoring the rolls and the material being ground. However, interrupting the grinding process may be required to do this, by which downtimes, and therefore production stoppages, occur. Furthermore, it depends on the experience and attention of a person skilled in the art to recognize wear, damage or insufficient product processing. Such results determined are imprecise and subjective. For objective detection of the wear of grinding rolls, comparing the actual condition with a target or initial condition has been proposed. For this purpose, to evaluate corrugated rolls, for example, profile prints of the roll surface are taken, as described in DE 10063377 A 1. Furthermore, analysis processes are proposed that use light sources and photodetectors for a visual recognition of the roll surface, as explained in WO 2017/140928 A 1. Such processes for determining the wear of grinding mils are therefore limited to the analysis of the surface condition at a given time, so that damage or loss of yield from wear that is already present are not prevented. Furthermore, such processes disregard other parameters of the grinding mil and its surroundings, which contributes to wear and may affect the productivity of the grinding mill. Furthermore, these processes are expensive and time-consuming.
Electronic monitoring processes based on a sensory data detection of measurement parameters have been developed, detecting a state, or wear, of rolls of a grinding mill, such as described in WO 2021/037525 A1. In this case, a sensor is arranged inside a grinding roll. The sensor designed to detect measurements that characterize a state of the rolls. In particular, this may relate to a state of a circumferential surface of the rolls. The state can be, for example, a temperature, a pressure, a force (component force(s) in one or more directions), wear, a vibration, a deformation (extension and/or deflection path), a rotational velocity, a rotational acceleration, an ambient humidity, a position or orientation of the rolls and are detected with appropriately designed sensors. The condition of the grinding roll is detected continuously while the grinding mill is in operation. Furthermore, a data transmitter is provided for contactless conveying of measurements of the sensor to a data receiver and further to a control unit or a superordinate control system for evaluation, by which the grinding mill or part thereof can be controlled and regulated. For example, a warning message can be emitted by a control unit if a preset warning criterion is met. For example, the warning criterion may consist of the measurement exceeding a preset imit. If the warning criterion is met, a warning signal can be emitted or the grinding mill can be stopped, for example, by the control unit. However, in this monitoring process, effects outside the grinding roll are disregarded. It may cause undesirable downtimes, loss of yield and excessive maintenance costs.
A grinding mill with grinding rolls is known from document EP 3500370 A1, in which the rolls exhibit several sensors for detecting measurements describing a state of the rolls, and which is designed to optimize the operation of the grinding mill by means of a control unit and to specify a remaining service life, and/or a wear condition, of the rolls. The sensors are, for example, designed as temperature sensors for ascertaining a temperature profile of the rolls, as vibration sensors for detecting vibration of the rolls and as accelerometer for monitoring a rotational velocity, acceleration or deceleration of the rolls, and transmit their measurements to the control unit. The control unit comprises a machine learning unit with which the roll operation, such as the width of a gap between two rolls or the parallelity of the rolls is automatically optimized, based on the measurement data received. Furthermore, by means of the machine learning unit, the remaining service life and a wear condition of the rolls is determined. In so doing, the machine learning unit comprises a monitoring unit for monitoring the measurements received and a learning unit. The monitoring unit detects, for example, the trend over time of the temperature, the gap width and rotational velocity depending on an actual and target value. The learning unit undertakes the learning process by Inking up the actual and target value. In this way, the operation of the grinding mill can be optimized by means of the machine learning unit in relation to shape, spiral and surface condition of the roll. This considers both the remaining service life and the wear condition of the grinding mill components. However, no assertion can be made on the optimization of maintenance work for upkeep of the grinding mill. This may result in unnecessary costs and downtimes, and the efficiency of the grinding mill may be affected.
It is a task of the present invention to provide a system and process for monitoring wear of components of a grinding or rolling mill, particularly for technical maintenance over the service life of such mills, which enable cost-saving and material-saving maintenance of the mill an optimum time for replacement of grinding mil components and a cost-saving and material-saving integration of the wear behavior of the mill within its life cycle. In particular, such a system and process for a grinding or rolling mill is to be provided that reduces downtimes for maintenance work and at the same time avoids excessive loss of yield, loss of quality and material consumption over the life cycle of the mill. Furthermore, for such mills, a timely indication for undertaking maintenance work and forecasting of an anticipated remaining service life of grinding rolls of these mils is to be provided. The predominant technical problem underlying the invention consists, in summary, of specifying a process and system for a mill for grinding and/or coarse-grinding particularly of cereals, by which the grinding and/or coarse grinding can be optimized and undertaken automatically, and which increases the operational safety and service life of such a grinding mill.
In accordance with the present invention, these tasks are achieved by a process and system for monitoring wear on grinding mill components and by a grinding mill with such a system with the characteristics of the independent claims. Furthermore, from the dependent claims and the relevant descriptions, further advantageous illustrative examples and variants may be derived.
A process and system for monitoring wear on components of a grinding mdl particularly for monitoring wear on grinding rolls or a grinding roll pair of a grinding mil, in accordance with the invention, ascertain an optimum future time for maintenance of the grinding mill, particularly maintenance of a grinding roll or a grinding roll pair. The process is particularly used for maintaining the grinding mill over the life cycle of the mill. In the following, the process can also be designated briefly as a monitoring process or as a maintenance process. The process is undertaken by means of a system comprising a control unit to control the grinding mill, particularly for controlling the grinding rods and/or grinding roll pairs, a sensory system for detecting measured data for technical parameters in relation to a wear condition of a component, particularly a grinding roll or a grinding roll pair, and for detecting measurement data on technical parameters in relation to an operating state of the grinding mil, an analysis unit for analyzing wear behavior of the grinding mill and at least one data transmitter and at least one data receiver for exchanging data.
The sensory system detects the measurement data on the wear condition of at least one component, particularly a grinding roll or a grinding roll pair, and the measurement data on the operating state of the grinding roll, periodically or continuously over time and provides the measurement data of the analysis unit, for example, by means of a data transmitter. The sensory system may comprise several measurement sensors to do this.
The analysis unit assigns a degree of wear of the at least one component to the measurement data of at least one of the parameters on the degree of wear of at least one component. Furthermore, the analysis unit assigns a maintenance loss to the degree of wear, which maintenance loss corresponds to a loss of grinding yield due to technical maintenance of the at least one component. The maintenance loss may, for example, be determined by a failure of a grinding yield due to a stoppage of the grinding mill and/or the costs of removal of the wear. Therefore, for example, the maintenance loss may depend on the extent and time period of required maintenance work and materials for remedying of wear on the component. From several measurement data detected at different times on the wear condition, the analysis unit derives a future wear condition at a time T in the future. The analysis unit assigns a future degree of wear and a future maintenance loss to the future wear condition. For example, the future wear condition may be ascertained by usual extrapolation processes from measurement data collected periodically or dynamically. The future degree of wear and the future maintenance loss are correlated with the future degree of wear and may therefore be derived therefrom.
In so doing, the analysis unit can be provided in a digital cloud platform. Therefore, the analysis unit of several, geographically-separate sites are used for deployment at various grinding mils. The analysis unit may therefore be updated simply and used multiple times.
Furthermore, the analysis unit assigns the measurement data for at least one parameter for the operating state of the grinding mill to a grinding yield level specifying the yield from operation of the grinding mill. The analysis unit compares the grinding yield level with a preset target yield level of the grinding mill and determines a grinding yield loss relative to the target yield level. The target yield level may, for example, be given by a technical mill specification of the mill manufacturer or operators. Also, the target yield level may be a theoretical ideal yield level for the grinding mill to be monitored calculated from the technical key data from this mil, or the target yield level may be determined by a practical test run of the mill as long as there is no wear present on the mill components. The grinding yield level ascertained from the measurement data on the operating state at an actual time is based on the wear of the grinding components, particularly grinding rolls, or grinding roll pair, generally below the target yield level specified for a grinding mil, producing a loss of grinding yield. For example, the yield from the grinding operation of the grinding mi is reduced in that, due to the wear, there is an increased energy requirement on the mill or additional passages are required to maintain grinding quality. The analysis unit derives a future grinding yield loss at a time Toperation in the future, from several pieces of measurement data on the operating state detected at different times. The future operating state may, for example, be ascertained by extrapolation processes. The future grinding yield loss correlates to the future [operating state] and may therefore be determined from the measurement data of the operating state.
The analysis unit optimizes a maintenance time in the future, by establishing as the future maintenance time that time at which the future maintenance loss essentially corresponds to the future grinding yield loss. Advantageously, there is a dynamic optimization, in which the analysis unit incorporates periodically or dynamically actual measurement data of a wear condition of a component and actual measurement data relating to an operating state of the grinding mill continuously into the analysis of the wear behavior, and ascertains an updated degree of wear, an updated maintenance loss and an updated grinding yield loss and determines an actual, optimized future maintenance time therefrom.
The monitoring process in accordance with the present invention uses the technical parameters to determine the condition of the grinding mill and ascertains, depending on these technical parameters, precautions for technical maintenance of the grinding mill. With the monitoring process, the technical functioning of a grinding mill can be optimized over the entire life cycle of the grinding mill. In particular, undesirable or excessively long downtimes of the grinding mill can be reduced or avoided, an effect on the grinding yield can be minimized and a reduction of grinding capacity over time can be reduced. As a result, the service lie of the grinding mill can be extended and/or its profitability can be improved. The monitoring process also supports careful usage of materials and other resources.
In an advantageous variant of the monitoring process in accordance with the invention, the analysis unit ascertains from the measurement data on the technical parameters relating to a wear condition of a component and/or from the measurement data on the operating state of the grinding mill, at least one specific maintenance task required for specific wear. Advantageously, the analysis unit sets a future maintenance time for this required specific maintenance task as that time at which the specific future maintenance loss resulting from this specific wear corresponds to the specific future grinding yield loss resulting from this specific wear. Examples of specific maintenance tasks are a replacement of a roll shaft, a roll stump or a roll bearing or the entire roll, balancing out of the rolls and grinding and polishing for smooth rolls. The monitoring process may set a future maintenance time for each such specific wear.
In a further advantageous variant of the monitoring process in accordance with the invention, the analysis unit aggregates measurement data from various parameters on the wear condition of at least one component and/or various parameters on the operating state of the grinding mill by means of an aggregation module. On the basis of the aggregated measurement data, the analysis unit of the at least one component can be assigned to an aggregated degree of wear and an assigned aggregated wear loss. Furthermore, the analysis unit of the operating state of the grinding mil can be assigned to an aggregated grinding yield loss. For example, in the aggregated degree of wear, measurement data may be affected in relation to temperature, vibration and rotational velocity of a grinding roll, the gap distance of a grinding roll pair, ambient humidity etc. In the aggregated grinding yield loss, measurement data on energy consumption of the grinding mill, the quantity and quality of the grinding yield etc. may be incorporated. A plurality of measurement sensors of the sensory system can detect measurement data on various parameters and transfer them to the analysis unit. The analysis unit aggregates the plurality of measurement parameters for an aggregated wear condition, and/or an aggregated operating state. In so doing, advantageously, various parameters can also be weighted. For example, parameters for determining wear of a component that have a high relevance, may have a higher weighting than parameters that are less relevant.
Advantageously, measurement data for various types of wear may also be considered, such as the specific types of wear mentioned above, and/or various components, and be aggregated into a common degree of wear of the component or the entire grinding mill. The various types of wear and components can therefore be in turn assigned a different weighting.
By using aggregated measurement results, it is possible to incorporate the effect of various wear types and their effects on the operation of the grinding mill in determining the maintenance loss and the grinding yield loss. A complete consideration can be made, in which the individual influencing factors on the technical overall efficiency of the grinding mill are considered.
For the monitoring process in accordance with the invention, the sensory system of the monitoring system advantageously comprises several measurement sensors which are arranged distributed in or close to the grinding mill. Preferably, measurement sensors are used which detect the measurement data on a temperature of components, a roll profile and/or a roughness of grinding rolls of the grinding mil, a rotational velocity of the grinding rolls, a vibration of the grinding rolls, a gap of rolls of a grinding roll pair, energy consumption of the grinding mill production quantity of the grinding mill, a grinding level of the material being ground, a time since last maintenance and/or downtimes of the grinding mill. The measurement sensors for determining the roll profile of corrugated rolls particularly detect a contour of the flute e.g. its angle, gradient, rounding off, etc. For smooth rolls, particularly the surface structure is detected. The measurement sensors may also be designed as sensor units with several construction elements. For example, an optical sensor unit may be provided comprising a light emitter and a light receiver, such as a camera.
In an illustrative example of the monitoring system. For example, at least one temperature sensor and a vibration sensor are arranged on a grinding roll of the grinding mil. Furthermore, the grinding mill may advantageously comprise a data transmitter and a microprocessor to provide measurement data on the grinding roll for the analysis unit. In so doing, a type of roll wear measurement device is provided on the grinding roll.
In a further advantageous variant of the monitoring process in accordance with the invention, the analysis unit makes a forecast of the future maintenance loss and the future grinding yield loss, by means of a regression module and/or an interpolation module. The regression module uses, for example, the temperature, the surface condition and the vibration of a grinding roll as independent parameters to determine the behavior of the degree of wear and ascertain this for the future. Also, the energy consumption, grinding level of the material to be ground and its quantity may be used to determine the grinding yield loss, to ascertain a value therefrom for the future. By deploying a regression or interpolation module, proven statistical processes for reviewing the technical condition of the grinding mill and for determining the wear behavior may be utilized.
In turn, in a further advantageous variant of the monitoring process in accordance with the invention, the analysis unit comprises a module for machine learning and may automatically ascertain the future maintenance loss and the future grinding yield loss, particularly these values can be optimized automatically. With the module for machine learning, machine learning module for short, it is possible to optimize the future maintenance time self-adaptively. The machine learning module may be designed for various types of machine learning, for example, for monitored learning, non-monitored learning, partially-monitored learning, corroborative learning, transductive learning, multi-task learning and similar. Using the machine learning module, the analysis unit can continuously adapt the analysis process, wherein the measurement data continuously detected by the sensory system and target value for the operation of the grinding mill can be used.
In an advantageous extension of this variant of the monitoring process in accordance with the invention, the module for machine learning sends a control signal to the control unit for regulation of the operation of the grinding mil, wherein the operation of the grinding mill is optimized corresponding at an advantageous and/or desired maintenance time, self-adaptively in such a way that the future maintenance time corresponds to the advantageous maintenance time. In the life cycle of the grinding mil, in the practical deployment of the mill, various times may be provided for a maintenance task. For example, maintenance of the mill may be provided for advantageously, if the grinding mill is adopted to a different grinding material or the mill is to be stopped for other reasons, for example, even non-technical ones. Such an advantageous maintenance time may be before or after a future maintenance time that is ascertained by the monitoring system. Through the machine learning module, an optimized operation of the grinding mill may be determined therefrom in a reverse conclusion.
In so doing, advantageously an optimization of the operation of the grinding mil may occur by optimization in relation to a parallelity of grinding rolls of a roll pair, a mutual gap of the grinding rolls and/or a rotational velocity of the grinding rolls, based on the future maintenance loss ascertained from the module on machine learning, and the future grinding yield loss. If, for example, an advantageous maintenance time is only somewhat later than a future maintenance time ascertained by the analysis unit, the operation can be optimized to the effect that, from the control unit, a somewhat resource-saving or energy-saving grinding operation or similar is set. This may, for example, be the case with unforeseen events that make normal maintenance procedures impossible, in contrast to this, if the advantageous maintenance time is earlier than a future maintenance time ascertained by the analysis unit, the operation can be made more intense, by which faster wear may occur, however, that can be remedied already at the earlier advantageous maintenance time.
In a further advantageous variant of the monitoring process in accordance with the invention, in addition to the measurement data from the sensory system, specification data on the grinding mill and/or a material to be ground are processed from a data pool to optimize the maintenance time in the future, for determining the future maintenance loss and future grinding yield loss. The data pool may, for example, be provided by means of a cloud platform. The data pool advantageously provides data relating to a specific grinding mill, particularly data on costs of material and labor in a maintenance task, energy costs for operation of the grinding mill at the site of the mil and/or information on grinding material, such as advantageous temperature ranges for grinding, normal number of passages required, purchase price of grinding material or sale price of the ground flour. Advantageously, these specification data may continuously be adapted to actual values, so that also at the future maintenance time, actual specification data can be considered. Advantageously, the data pool may provide measurement data on technical parameters in relation to a wear condition of a component and/or an operating state of other, comparable, grinding mills, to determine the future maintenance loss and optimizing the future grinding yield loss by comparison and/or incorporation of these pieces of measurement data. In this way, the module for machine learning can learn from these other, comparable grinding mils and further improve the optimum maintenance time further self-adoptively.
The monitoring system in accordance with the invention is advantageously constructed from units and/or modules that are provided at least partially in the cloud platform. In addition, the cloud platform can be used as a data memory for the measurement data. The cloud platform is used as a large central database and provides working units for implementing the process which can be used for various grinding mills at distributed sites. The monitoring system on the individual grinding mills can therefore be designed in a simplified and cost-saving way.
In a further advantageous variant of the monitoring system in accordance with the invention, an output unit may visually display a degree of wear of at least one component and/or a maintenance loss in relation to at least one component and/or a grinding yield loss of the grinding mill as a curve over time. Advantageously, in so doing, even future values and the ascertained future maintenance time are displayed. An operator of the grinding mill con read off the trend of the mi wear in a simple way from the display. In this way, the individual degrees of wear and wear losses on the various components, the projected values and also the aggregated values are displayed. Advantageously, the output unit comprises a visualized, tailored dashboard format designed in such a way that wear reports, recommended future maintenance times with forecasts, and/or with recommendations on replacing rolls and information on grinding operation and its optimization are displayed automatically. The operator may be sent the reports to their personal business account, improving process transparency. For example, a manufacturer of grinding mils may provide servicing software in which individual data of the operator and data on its grinding mill can be administered. The operator uses this servicing software by setting up a business account on the software platform, to make the data and information on the grinding mill accessible to an operator in a simple and transparent way.
In yet another advantageous variant of the monitoring process in accordance with the invention, the measurement data on technical parameters in relation to a wear condition of a component and an operating state of the grinding mdl are loaded by means of the data transmitter into a cloud platform and/or the data pool with data relating to a specific grinding mill and/or data relating to other, comparable grinding mils may be provided in a cloud platform. The decentralized warehousing, storage and processing is useful for process security and extends the processing volume. In this way, with the monitoring process, a more reliable maintenance schedule can be compiled and continuously updated without delays, as is only conditionally the case with local storage capacities.
In a further advantageous variant of the monitoring process in accordance with the invention, a servicing module of the monitoring system, based on the ascertained future maintenance loss and the future grinding yield loss, automatically recommends a cycle of maintenance for the grinding mill. In addition or alternatively, the servicing module may make an offer for a maintenance task of the component and/or a compile relevant maintenance order automatically. For example, a servicing module derives a required maintenance procedure for this from the wear condition ascertained. The procedure may comprise a cycle of individual maintenance activities and list of equipment that it is be replaced. From this, an offer with schedule and costing can be compiled automatically. An operator of the grinding mill can accept this offer, by which the maintenance procedure can be activated automatically. In this way, equipment can be ordered and maintenance staff can be booked.
In a next advantageous variant of the monitoring process and monitoring system in accordance with the invention, a means of identification is provided on at least one of the monitored components, particularly on a grinding roll. The means of identification exhibits electronically-stored data in relation to the component. Through the means of identification, the component of the grinding mill can be uniquely identified. For example, the means of identification can be provided with individual data on the component and in relation to at least one characteristic of the roll, such as at least one of its dimensions, its dishing and/or a product number. To do this, the component may, for example, exhibit at least one data memory that is, for example, designed as an RFID chip. The data stored in the data memory may, advantageously, be transferred contactlessly by means of a data transmitter to the analysis unit. In this way, it is possible that the data of the means of identification are transmitted by means of the same data transmitter, by means of which the measurement data relating to the wear condition and the operating state are transferred.
The task of the present invention is also solved by a grinding mill with grinding roll, particularly with corrugated or smooth rolls, comprising a system as described above. The grinding mill in accordance with the invention is preferably designed for grinding wheat and/or rye and/or durum wheat and/or oats and/or barley and/or peas and/or chick peas and/or pulses and/or rape and/or soya and/or cacao and/or coffee as a grinding material.
In a simple example of the application of the monitoring system and process in accordance with the invention, measurement parameters of the roll wear measurement device are uploaded to a digital cloud platform and the measurement parameters measured by the roll wear measurement device are automatically analyzed by the analysis unit of the digital platform. An operator may be sent an automated display of the wear results as reports with forecasts and recommendations for roll replacement and information on process transparency and optimization and in the visualized, tailored dashboard format on their personal business account. The analysis unit links the measurement results to the servicing module for compiling a corrugated and smooth roll overhaul and replacement service and for automatically compiling an offer and a corresponding order for the overhaul/replacement services of corrugated and smooth rolls. An identical procedure may be used for other components, such as, for example, feed rolls, actuators, infeed equipment and similar.
With the system and process for monitoring wear on components of a duly equipped grinding mdl, the maintenance of the mill and the production of material that has been ground over the entire life cycle is improved and optimized. The quality and quantity of the grinding result is sustainably improved. Regressive yield of the grinding mill is avoided.
Advantageous illustrative examples of the invention shall be illustrated in the following using the figures, which are only for the purpose of information and are not to be interpreted as restrictive. Characteristics of the invention becoming apparent from the figures are to be considered as forming part of the disclosure of the invention individually and every combination. In the figures:
As an introduction to the field of the invention.
A process and system for monitoring wear on components of a grinding mill and for maintaining the grinding mill in accordance with the invention and variants thereof are explained in the figures by way of example and in extracts. As an overview,
Furthermore, the monitoring system comprises a control unit 3 for controlling the grinding mill, particularly of the roll par 2, which control unit is arranged advantageously in the girding mill. Furthermore, a sensory system 4 for detecting measurement data on technical parameters in relation to a wear condition of a component, particularly of the grinding rolls, and an operating state of the grinding mill is provided. The sensory system 4 comprises a plurality of measurement sensors for detecting measurement data on technical parameters in relation to a wear condition of a component and/or an operating state of the grinding mill. For example, the sensory system comprises one or more temperature sensors 4.1 for measuring the temperature of the grinding rolls 2, their environment and/or the ground product 110, one or more vibration sensors 4.2 for measuring a vibration of the grinding rolls 2, one or more accelerometers 4.3, preferably at least one for each one grinding roll 2, one or more moisture sensors 4.4 for detecting the moisture of the environment of the grinding rolls 2 and/or the ground product 110, an energy consumption sensor 4.5 for detecting energy consumption of the grinding mill 1 and sensors 4.6 for detecting measurement data on quality and quantity of the ground product 110. Furthermore, measurement sensors 4.7 for ascertaining a surface characteristic, and/or a surface condition, a gap of the grinding rolls 2 and the mutual parallelity of the grinding rolls 2 and measurement sensors 4.8 for ascertaining a means of identification 5 of the grinding rolls 2 are provided. The measurement sensors 4.1-4.8 of the sensory system 4 detect wear measurement data 40 on technical parameters relating to a wear condition of a component, particularly the grinding rolls 2 of the grinding mill 1, such as the characteristics of the roll surface, the roll gap, the roll parallelity and the roll temperature. Furthermore, the measurement sensors 4.1-4.8 of the sensory system 4 detect operating measurement data 50 on technical parameters of an operating state of the grinding mill 1, such as energy consumption, ambient temperature and moisture, rotation and/or change of rotation of the grinding rolls 2 and measurement data on quality (e.g. graininess of the ground product) and quantity (such as a weight, and/or a change of weight of the ground product). The sensory system detects the measurement data 40 on the wear condition of at least one component and the measurement data 50 on the operating state of the grinding mill periodically or continuously over time, so that there is a series of measurements extending over a defined period of time. The defined period of time may extend, for example, from a commissioning of the grinding mill or from the last maintenance task or from other predetermined events of the grinding mill.
An analysis unit 6 of the monitoring system analyses a behavior of the grinding mil 1 in relation to a wear of the components and/or a wear-dependent change of the operation of the grinding mill over time. The analysis unit 6 may be provided in a computational device, such as a computer, of the grinding mill 1. Advantageously, the analysis unit 6 in accordance with the invention is, however, provided in a cloud platform 7. In such a way, the analysis unit 6 may be a component of a monitoring system for various, mutually independent grinding mills. By using a cloud platform as a central point for the analysis unit 6, furthermore, a high working capacity for the system is provided and the computational device of the grinding mill can be designed with a lower working capacity. The measurement data 40 and 50 detected by the sensory system 4 on the technical parameters of the grinding mill 1 are provided by one or more data transmitters 8 present in the grinding mill 1, preferably contactlessly for the analysis unit 6. The data transmitters 8 may advantageously be provided on the component to be monitored or in their immediate vicinity. For example, a data transmitter may be provided on a grinding roll, preferably on both grinding rolls 2. Further data transmitters may be provided on an energy supply to the grinding mill, in a storage room of the grinding material 100 and/or a storage room for the ground product 110. Advantageously, the measurement sensors may be equipped with the data transmitters. The data may be transmitted by means of a network connection to the analysis unit 6 and/or to the cloud platform 7. Advantageously, the measurement data are stored in a storage space in the cloud platform 7 and provided to the analysis unit 6. To receive the measurement data, the analysis unit 6 and/or the cloud platform 7 comprises at least one data receiver 9.
Furthermore, the system for monitoring wear on components of a grinding mill in accordance with the invention comprises a data pool 10. The data pool 10 is advantageously also provided in the cloud platform 7, but may also, for example, be accommodated in the computational unit of the grinding mill 1. The data pool may contain additional data that are helpful for an analysis of wear and a future maintenance time. For example, specification data 60 of the grinding mill 1 can be stored in the data pool. The specification data 60 may comprise mil-specific data and thresholds for the grinding production, such as target yield level, a target temperature level for the grinding rolls 2 and/or the grinding material 100 and/or the ground product 110, a target moisture level for the ground product, target values for the surface characteristics, parallelity and gap of the grinding rolls 2, measurement data of the grinding rolls 2, information on grinding material 100, information relating to costs, availability and anticipated energy consumption of components, information on the ground product 110, such as target temperature, target moisture and sale value. The specification data 60 may be continuously updated in the data pool 10, so that the analysis unit 6 can be provided with current specification data 60 at any time.
The totality of the data detected over time consisting of wear measurement data 40, operating measurement data 50 and any specification data 60 form a multi-dimensional data space forming the basis for the analysis unit 6 for ascertaining an optimum maintenance time in the future for maintenance of wear and for maintenance of the grinding mill. To do this, the analysis unit shows a future wear curve, a future maintenance loss and a future grinding yield loss configured with an analysis algorithm ascertained from the data available in the data space. From these projections, the analysis unit then ascertains an optimum future maintenance time. Essentially, statistical processes and/or experimental modeling processes can be used to analyze the data and for a curve forecast, in which confidence levels and probabilities inked to the parameters can be predefined. The analysis unit 6 may also comprise a module for machine learning 11 that automatically optimizes ascertaining the future maintenance time. The machine learning module 11 accesses the data in the data space to do this and uses the machine learning processes, particularly processes based on a pattern recognition, continuously to improve the analysis of a wear curve. In this way, the machine learning module 11 identifies the contexts in patterns in an analyzed dataset from the data space and uses these contexts on the new datasets, such as on datasets of other grinding mils or of other time windows of the data detection. So, it is advantageous to use an algorithm based on monitored learning. The algorithm is thus trained with existing series of measurement data and relevant known wear characteristics and relevant yield losses. The time for the maintenance task is ascertained as a target variable, at which a total grinding yield loss is optimized. Alternatively, an algorithm based on unmonitored learning can also be used, particularly if only fewer pieces of comparison measurement data are available for a context between wear and grinding yield loss.
The system for monitoring wear on components of a grinding mill in accordance with the invention may further comprise an output unit 12 which displays visually the results from the data analysis, particularly the curve of wear and a determined future maintenance time, as a curve over time. Advantageously, a curve beyond the maintenance time is shown, to illustrate the anticipated wear curve and grinding yield loss, if wear is not remedied, therefore no maintenance is carried out. The output unit 12 may be provided on the grinding mill 1, such as on the computational unit. Furthermore, the output unit 12 may be designed on a mobile device, such as a smartphone or tablet, which communicates with the analysis unit over a network. As well as the visual illustration of a curve of the technical parameters and of analysis results, quantitative information in relation to an operating state and a wear curve can be shown. Examples of a graphical illustration of the results from the monitoring process are explained in the context of
Furthermore, the monitoring system in accordance with the invention may comprise a servicing module 13 that, preferably, based on the analysis results, recommends a cycle for maintenance of the grinding mill and/or gives an offer of maintenance of components and/or a maintenance order automatically. The servicing module 13 may, for this purpose, for example, relate to specification data 60 from the data pool 10, such as availability of replacement components, costs of the components, labor costs, etc. The offer may advantageously be shown on the output unit 12. Advantageously, the servicing module 13 is provided in the cloud platform 10 and may be the component of several monitoring systems provided for various grinding mils.
In an analysis step 220, the analysis unit 6 assigns the measurement data 40 to at least one parameter on the wear condition of at least one component of a degree of wear and the degree of wear a value for a maintenance loss 300 (see
In addition.
In summary, using the present invention, the operation of the grinding mill is improved by maintenance and upkeep optimizing the mdl. This is done by technical monitoring of the mill components and the products processed with the mill. Furthermore, the operation is improved by digitalizing the monitoring and displaying the results of this monitoring transparently and comprehendibly. A process and system in accordance with the present invention are suitable for measuring the wear condition of cereal processing rolls including corrugated and smooth rolls for corresponding grinding material by using a roll wear measurement device. Measurement parameters of the roll wear measurement device are advantageously uploaded to a digital cloud platform, and the measurement parameters measured by the roll wear measuring device are automatically analyzed by the analysis unit of the digital platform. A user is sent an automated display of the wear results and reports with forecasts and recommendations on replacing rolls and additional process transparency/optimization in a displayed, tailored dashboard format to their personal business account, that can be made available to them as a service by the mill manufacturer. For an operator of a grinding mill, it is of the utmost importance to avoid yield losses and downtimes. Yield losses arise, from a technical perspective, particularly from the abrasion of components of the grinding mill which causes a drop in throughput. When grinding rolls for grinding of grinding material are worn, a high contact pressure of the rolls of a grinding roll pair is required, by which the energy consumption of the grinding mill increases.
Illustrated in a simplified way, a surface temperature of a shell surface of at least one roll of the grinding mill and/or the temperature of a ground product are measured, and with at least two temperature sensors which measure the temperature of the at least one roll or a layer of product in various places. In a monitoring process in accordance with the invention, it is possible to detect and monitor the temperature where it is generated, in other words, on the surface of the rolls. Furthermore, to monitor the roll temperature, the temperature of a ground product is monitored directly, as the roll transfers heat to the ground product and by measuring the temperature of the ground product, a conclusion as to the temperature of the grinding rolls is possible.
In on illustrative example of the process and system for monitoring wear on components of a grinding mill, a monitoring device for automated optimization of a control system of a grinding mill is constructed, as illustrated in potent application EP 3500370 B1 of the applicant. In this monitoring device, the control system of the grinding mill, particularly its grinding rolls, is optimized automatically by evaluation of measurement data on components of the grinding mill by means of a machine learning unit over the service life. However, the monitoring device does not determine any optimized maintenance time based on wear measurement data, operating measurement data, specification data and any additional information, as the present invention proposes. At least for the design of the grinding mil, the arrangement of measurement sensors on the grinding rolls, the description of wear on smooth rolls and on corrugated rolls and other characteristics in the context of operating grinding mils in the prevent invention are found in full in the description on this matter from patent application EP 3500370 B1. This description is hereby to be recorded in the description of the present invention. This particularly relates to the description of the following figures from EP 3500370 B1. In
In a variant of the monitoring process in accordance with the present invention, the surface characteristics of smooth rolls 2.1, as it is shown in
In a further variant of the monitoring process in accordance with the present invention, the surface characteristics of corrugated rolls 2.2, as it is shown in
In
To determine the energy-saving potential, a mathematical model is used by the analysis unit, for example, for various types of wheat, that has been worked out on the basis of real experiments with statistical test planning on a laboratory roll stand. In the model, the wear of the rolls as a percentage in relation to the cross-sectional surface of the flute is used as variable A, the mass flow in kilograms per second as variable B and the ejection on a 1120 micrometer screen as a percentage is used as variable C. From the tests, a model for calculating the specific grinding energy according to the following formula has been produced:
Specific grinding energy=1.845+0.057A+10.00185B−0.05C−0.00042AB−8.000184A2
In this way, the energy saving potential can be determined from the comparison between any worn flute and a new flute.
In a grinding mill equipped with a monitoring system in accordance with the present invention, unnecessary downtimes are prevented on the basis of maintenance work or material failure, the productivity and the service life can be improved and the costs for operation of the mill can be planned transparently and optimized.
| Number | Date | Country | Kind |
|---|---|---|---|
| 00297/2021 | Mar 2021 | CH | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/057345 | 3/21/2022 | WO |
