WO2010000816A1 - Control system for grain processing systems - Google Patents

Abstract

The invention relates to a system for processing grains. The system according to the invention contains a milling unit for milling the grain seeds or grain pieces into grain particles such as meal or flour; a conveying line between at least two of the milling units; a global control system that extends across at least a majority of the units of the system; and/or at least one local control system associated with at least one respective unit and at most with a majority of the units. According to the invention, the system is controlled using a global control strategy for at least a majority of the units of the system and a local control strategy for at least one respective unit and at most for a majority of the units of the system.

Description

Control system for grain processing plant

The invention relates to a plant for processing of cereals, in particular for crushing, transporting, fractionating and conditioning grain and to a method for controlling such a process in such a plant.

Many known grain mills are very extensive and include comminution units for crushing cereal grains or cereal debris to flours and grain by-products, i. to various cereal particles and conveyor lines between the crushing units. Furthermore, such plants may contain fractionation units for fractionating the cereal particles taking into account at least one property of the particles. Before processing, i. Before entering the facility, the grain is subjected to conditioning that can take from several hours to several days.

The process of crushing and fractionating requires numerous process stages, which are carried out in a plurality of said units, and some of the units can also be run through by the product stream several times. To make matters worse, the quality of the grain used as starting material for the process can vary within the product stream. Nevertheless, the end product should always meet certain standards and standards, i. the flour, semolina and bran fractions must meet given product parameters.

Large systems with many different of the above-mentioned units are usually equipped with a control system that allows an experienced milling specialist (Obermüller) to keep a constant overview of the system to be monitored. However, since such systems often have a high number and also a large variety of units for product treatment, monitoring and ensuring an optimal operation of the system under the given conditions of the staff assigned to the operation and operation monitoring but still requires a lot of experience and constant Alertness. Optimal operation is therefore not always possible.

In particular, it is not customary in the milling industry to repeatedly (by product recirculation) pass a ground product through a unit of the plant, in particular not - either as a whole fraction or in partial fractions - repeatedly via one and the same roll mill. In practice, this leads to uncontrollable grinding product properties and is therefore avoided.

The invention is therefore based on the object to always optimally drive the process in a plant for processing grain.

This object is achieved by an inventive plant for processing of cereals, which comprises:

^ at least one comminuting unit for crushing cereal grains or cereal fragments into cereal particles;

> at least one conveyor line between at least two of

Crushing units; ^ a global regulatory system that covers at least one

Most of the units of the plant extends; and / or> at least one local regulatory system associated with at least one respective entity and at most a majority of the entities. The inventive method for controlling a process for processing grain especially in the inventive system is carried out using

a global regulatory strategy for at least a majority of the units of the investment; and

> a local regulatory strategy for at least one unit and at most a large part of the units of the facility.

The plant according to the invention preferably also has:

at least one fractionation unit for fractionating cereal particles taking into account at least one property of the particles; and or

^ at least one mixing unit for mixing cereal grains or cereal particles; and or

> at least one conditioning unit for the conditioning of cereal grains, cereal fragments or cereal particles, with a relatively long pre-storage period (several minutes to several days) outside the plant or before undergoing the process and postconditioning during the period Can run through the process.

The following residence times or throughput times of the cereal particles are preferred in the context of the present invention: comminution: <20 s, preferably <10 s; ^ Promotion: <5 s, preferably <2 s;

Fractionation: <60 s, preferably <20 s;

> Post-conditioning: <1 min, preferably <20 s, in particular <10 s.

The individual units are connected to one another in a network-like manner, in particular via conveyor lines, wherein the network-type connections can preferably be changed during operation. Contrary to expectations, it has been found that with a system according to the invention comprising both a global and a local control strategy, the product return in units of the grain processing plant is made possible, and the desired ground products and their properties can be achieved very well. The coordination of several output and / or input streams of products from / to individual units as well as the online redirection of product streams from / to the individual units can be designed surprisingly reliable and with good quality of the final product. The uncontrollability of milling product properties assumed in the prior art when using product recirculations can be overcome with the methods and apparatus described in detail below.

Advantageously, at least part of the units can be coupled to one another in terms of product flow and / or regulation in the system. Coupling in this sense means a return of product and / or information of the control system.

The global control system suitably uses a set of global guidelines, preferably including less than 50 principles and more particularly less than 20 principles. In addition, the global control system can specify local specifications for a local control system of the respective units of the plant. The guiding principles may be rules of a fuzzy logic system.

Typically, starting from one cause, a (global) guiding principle comprises at least one effect and at least one action (which may also be the at least partial retention of previous settings); eg:> cause:

Climate suddenly becomes moister (thunderstorm breaks out); > Impact:

Less sharp sighting on Ausmahlpassagen;

> Action 1:

More product on Mahlpassage A than on Mahlpassage B.

Of course, further (consequential) effects and (sequential) actions may be included in one of the guiding principles. In the example above:

^ (Consequence) effect (of action 1): grinding passage B less loaded; Meter reports higher water absorption;

> (Sequence) action 2:

Guide the grinding gap of the grinding passage B higher.

The global control system and / or a local control system expediently output manipulated variables to actuators for acting on units of the system. The response times (response times) of the actuators are preferably <5 s and more preferably <1 s.

Preferably, at least some of the units are coupled together. Coupling is understood as meaning both a coupling of the product streams between the units and a coupling of the information flows (data streams) between the units. For the latter, in particular, neural networks are provided which extend across the global and local control systems. In addition or as an alternative, blurring logic systems can be provided.

The units have a product conveying direction in which the grain particles pass through the units. Preferably, some of the conveyor lines are formed as product loops connecting the exit of a unit with the entrance of this unit or the exit of a unit with the Join the entrance of an upstream unit. It is advantageous if a part of the loops is arranged as coupled loops or intermeshing loops.

Preferred residence times or throughput times through the loops are in the range <100 s per pass, preferably <10 s per pass.

The preferred number of passes through the loops is <5 passes, preferably <3 passes.

The couplings and loops can be turned on or off or turned off or closed as needed during the process.

Conveniently, the local control system uses a set of local policies, preferably including less than 30 policies, and more particularly less than 10 policies.

Starting from one cause, a (local) guiding principle typically also includes at least one effect and at least one action (which may also be at least partially maintaining previous settings); e.g .:

> Cause: other crude product;

> Impact:

Particle size at the product outlet too large;

> Action 1: Narrow the grinding gap.

Of course, further (sequential) effects and (sequential) actions may be covered by a (local) guiding principle as explained above in the context of the Global Guidelines. The at least one local control system has one or more of the following controls: P controller, I controller, PI controller, ID controller, PD controller, PID controller, or other common controllers. Preferably, regulators that use neural networks and / or fuzzy logic are also used.

Preferably, the global and / or the local control system are designed as adaptive systems.

The local control system is designed so that it can receive specifications for operating parameters of the unit assigned to it.

The scope ("diversity") of the plant is preferably limited to:

> has a maximum of five different types of comminuting units; and or

^ has a maximum of seven different fractionation units; and or

> has a maximum of three different types of conditioning units.

The scope of the system is also preferably limited by having a maximum of 15 different units controllable by the local control systems and by the global control system.

Even plants which have a maximum of two types of comminution units and / or a maximum of two types of fractionation units and / or a maximum of two types of conditioning units are possible because of the control systems according to the invention. Preferably, as a sort of crushing unit, a shearing device, and in particular a roller mill, is used.

Preferably, as a type of crushing unit, a baffle device and in particular an impact dissolver is used.

Preferably, a screening device is used as a sort of fractionating unit.

Preferably, an air classifier is used as a sort of fractionating unit.

Preferably, one type of fractionating unit used is a centrifugal-type device and in particular a cyclone.

Conveniently, some of the units and conveyor lines each contain sensors of their respective local control system. Preferably, all units contain a sensor. The response times (response times) of the sensors are preferably <1 min and more preferably <10 s.

Preferably, at least some of the crushing units, fractionating units, conveying lines, mixing units and conditioning units contain actuators of their respective local control system and / or actuators of the global control system. This allows, as required, the adjustment of a unit via a local control system or directly, and thus more quickly, through the global control system. The global control system allows faster control because it can be easier to adjust settings on upstream units, which manifest themselves only in properties of products downstream units. Such follow-up Correcting impacts through a chain of local hiring changes would be much more time-consuming.

Each comminution unit, fractionation unit, conveying section, mixing unit and conditioning unit preferably contains at least one sensor of its respective local control system and / or at least one actuator of its respective local control system.

Preferably, at least a majority of the crushing units, fractionating units, conveying lines, mixing units and conditioning units contain at least one sensor of the global control system and / or at least one actuator of the global control system.

Preferably, in the method according to the invention, the global control strategy uses a set of global policies, with the global control strategy in particular outputting local defaults for a local control strategy.

Before or during the procedure, the operator may enter defaults for the global control strategy and / or for the local control strategy. In this case, the local control strategy preferably receives specifications for operating parameters of the unit assigned to it.

In a preferred embodiment, the global control strategy operates continuously, with metrics constantly being collected, especially before, during, and after their change. The global control strategy may involve concurrent / coupled rules of multiple parameters.

In the preferred embodiment, however, the local control strategy operates discretely or discontinuously, with measurement are detected before and after their change, in particular only in a first stationary state before and in a second stationary state after its change. The local control strategy can also include the simultaneous / coupled control of several parameters.

Preferably, the local control strategy includes passing on information relating to at least one unit to the global control system, which information may include the degree of satisfaction of local defaults from the global control strategy to the local control strategy.

Similarly, the global control strategy and / or the local control strategy preferably include passing on information to a plant operator (Obermüller).

It is particularly advantageous if, in at least part of the sensors, the detection accuracy is adapted to the current needs of the control strategy. Thus, in the case of an initial rough approximation of a unit to a state (first approximation of a parameter variety), it is possible to work with a lower resolution, but with smaller data quantities, while during the subsequent closer approximation to the state (second approximation of the parameter values). Diversity) with a higher resolution, but can work with larger amounts of data. This saves computational effort and thus time.

A sensor of a local control system may receive a start signal or a wait signal from the global control system, from another local control system or from an actuator.

Preferably, the time histories of the global control strategy and local control strategies are logged and recorded. Thus, entire "libraries" with specific patterns of parameter diversity and appropriate rule strategies can be created and consulted later. Not only are optimal operating states, ie an optimal variety of values for a variety of parameters, but also non-optimal operating states stored. This is particularly useful, for example, if the system is to be restarted on Monday in order to continue a process interrupted in the previous week, if a sudden product change is required or if the raw material suddenly changes, ie if an unexpected change occurs Quality change is present.

In a further preferred embodiment, measured values and / or other sensor information are used to detect or even diagnose a system malfunction or a system error. Expediently, special measures are taken by the global control system and / or the local control system upon detection and, if appropriate, diagnosis of a system malfunction or a system error. Depending on the extent of the plant malfunction or plant failure, these may be the following measures for at least part of the plant: ^ further regulation of the faulty plant part or of the entire plant, taking into account the fault; ^ only taxes of the plant; ^ Stopping the system.

Overall, the embodiments according to the invention enable autonomous process control, flexible plant configuration and automatic adaptation to new situations (operating conditions, raw material properties, new end product specifications, etc.). Individual processing units of the plant is assigned a local control system. To control a roller mill, a baffle, a screen or a wind sifter various controllers can be used, namely P controller, I controller, PI controller, ID controller, PD controller, PID controller.

Further advantages, features and possible applications of the invention will become apparent from the following description with reference to the figures, wherein:

Fig. 1 shows a first variant of a local control;

Fig. 2 shows a second variant of a local control;

Fig. 3 shows a third variant of a local control;

4 is a schematic representation of the interaction of global control and local control in the method according to the invention; and

Fig. 5 is a schematic representation of the inventive system global control and local control.

6 shows a summary of a method according to the invention.

FIGS. 1, 2 and 3 show different variants of a local control for a local process. A local process takes place in one unit of the plant. This can e.g. the process be in a roll mill, sifter or conditioner. The following controller sizes are shown:

Setpoint r, target value y and set value u. The first variant of the local control shown in FIG. 1 uses two lxl PI controllers with two independent loops and four adjustable parameters. This allows a one-time and subsequently fixed setting by trial and error.

The second variant of the local control shown in FIG. 2 uses a 2x2 PI controller with two coupled loops and eight adjustable parameters. This also allows a fixed setting by trial and error (trial and error).

The third variant of the local control shown in FIG. 3 uses an adaptive 2x2 controller with two coupled loops and four adjustable parameters. This allows a continuous automatic adjustment. In the case of an operating point change, the gradient underlying the control is continuously adjusted.

4, the interaction of global control and local control is shown schematically. The operator or supervisor may specify certain end product targets and ancillary targets to the plant or system. These then determine the global regulation strategy. Examples of end product targets are e.g. the end product properties, end product yield, or product throughput through the plant. Examples of secondary goals include the energy required for the technical process, the wear and tear, the utilization, in particular remainder mixture and residual utilization, as well as the flexibility and overall cost-effectiveness of the process and the plant.

The global control acts on the processing units directly or via one or more local controls using actuators (eg roller mills, screens, etc.) of the system. The processing units of the system are shown schematically as a "grinding processor". The processing units in the grinding processor are provided with sensors that are supplied to the local regulations, the global control and the operator (Obermüller), where the operator is also a special alarm (eg optical, acoustic) is provided. The sensor information supplied to the operator can be prepared by a module for error detection and error diagnosis and, if appropriate, fed to the operator together with an alarm. The regulation takes into account the plant configuration as well as product recipes. The plant configuration represents the total number of units, the number of units of each type and the number of different types of units ("diversity") of the units in the plant. The product recipes include the raw material specifications as well as the process parameters.

The global control gives the local regulations intermediate product setpoints.

The operator can also specify raw material information as well as the available system scope (number / variety constellation of the system). In addition, the sensors can record the properties of the raw material before or at the beginning of the process, the properties of the intermediates in the plant or during the process and the properties of the final products after the plant or at the end of the process.

The process according to the invention can also be used advantageously in the development of a plant according to the invention. Thus, starting from a pilot plant with a given number and variety of units for the process for processing cereals using the local and / or global regulatory strategy, an optimal elaborate number / diversity constellation to achieve a given end product requirement.

In principle, it is possible to start with a small, usually insufficient, number / diversity constellation in order then to increase the number / diversity constellation step by step until the specified end product requirements are reached. Alternatively, conversely, too large, i. For given end-product requirements, a large number of diversity constellations is assumed, which is then gradually reduced until a point is reached from which the end-product requirements are no longer attainable.

Instead of the development / optimization of a pilot plant, the process according to the invention can also be used in an analogous manner for the design and simulation of a plant according to the invention.

For the overall optimization of the system / process configuration, a variety of parameters is used, which consists of system parameters or machine parameters on the one hand and process parameters or operating parameters on the other hand.

Certain parameters or constraints are defined for the individual parameters. Similarly, relations between different parameters are defined.

The individual parameters of this parameter variety are assigned different importance. This is preferably done by ranking and / or weighting individual parameters. Preferably, the individual parameters are also given limits for their values. For this purpose, setpoints, minimum values, maximum values and permissible value ranges are used for the individual parameters.

By defining input / output connections within individual local controllers and / or between different local controllers, relationships can also be defined for the individual parameters or between different parameters.

Another important group of constraints are equivalents between different parameter values and / or different parameter value changes within a parameter variety.

FIG. 5 schematically shows a schematic representation of the system according to the invention with global control and local control. The global control (GR) runs on a computer, eg a PC, with an interface to a control system (LS). The units of the system according to the invention are shown schematically, wherein each illustrated unit is representative of one or more units of a particular sort of units. The number of different represented units, ie number of different types of units, is thus identical to the "diversity" of the system mentioned above. FIG. 5 shows a conditioning and grinding machine group (KoMa) with a conditioning unit (Ko) and a size reduction unit (Ma), and a fractionation / sorting machine group 10 with three fractionating units and a sorting unit , Representative of the types of fractionating units are a Plansichter (PS), a zigzag sifter (ZZS) and a cyclone separator (ZS) shown schematically. Representative of the one sorting unit is a whole grain sorter (SX) shown. In addition, a switch assembly 9 or a multiplexer (MUX) representative of a product flow multiplexer for the multiplexing of product streams is shown schematically.

6 shows a summary of a method according to the invention, as described above.

Claims

claims 1. Plant for processing cereals, which comprises ^ at least one comminution unit for crushing cereal grains or cereal fragments into cereal particles; ^ at least one conveyor line between at least two of the crushing units; a global regulatory system that spans at least a majority of the units of the facility; and or at least one local regulatory system associated with at least one respective entity and at most a majority of the entities. 2. Plant according to claim 1, characterized in that it comprises at least one fractionation unit for fractionating cereal particles taking into account at least one property of the particles. 3. Plant according to claim 1 or 2, characterized in that it comprises at least one mixing unit for mixing cereal grains or cereal particles. 4. Plant according to one of the preceding claims, characterized in that it comprises at least one conditioning unit for conditioning cereal grains, cereal fragments or cereal particles. 5. Installation according to one of the preceding claims, characterized in that the units, in particular via conveyor lines, are network-connected. 6. Plant according to claim 5, characterized in that the network-like connections are variable during operation. An installation according to any one of the preceding claims, characterized in that the global control system includes a set of global policies. 8. Installation according to claim 7, characterized in that the global bale control system includes less than 50 guiding principles and in particular less than 20 guiding principles. 9. Installation according to one of the preceding claims, characterized in that the global control system local vorga- ben for a local control system of the respective units of the system can specify. 10. Installation according to one of the preceding claims, characterized in that the global control system manipulated variables 20 outputs to actuators for acting on units of the system. 11. Installation according to one of the preceding claims, characterized in that the local control system outputs control variables to actuators for acting on units of the system. 25 12. Installation according to one of the preceding claims, characterized in that at least a part of the units are coupled to each other in terms of product flow and / or the scheme. 30 13. Plant according to one of the preceding claims, wherein the units have a product conveying direction in which the grain particles pass through the units, characterized in that a part of the conveyor lines as Product loops are formed, which connect the outlet of a unit with the entrance of this unit or connect the outlet of a unit with the entrance of a conveyor-side unit. 5 14. Plant according to claim 13, characterized in that a part of the loops are arranged as coupled loops and / or intermeshing loops. 15. Installation according to one of the preceding claims, characterized in that the local control system includes a group of local guidelines. 16. Plant according to claim 15, characterized in that the local control system contains less than 30 guiding principles and in particular less than 10 guiding principles. 17. Installation according to one of the preceding claims, characterized in that the at least one local regulatory 20 System includes one or more of the following controls: P-controller, I-controller, PI-controller, ID-controller, PD-controller, PID-controller. 18. Installation according to one of the preceding claims, characterized in that the global control system is adaptive, wherein the parameters to be controlled can be adapted to the process. 19. Installation according to one of the preceding claims, characterized in that the local control system is adaptive, wherein the parameters to be controlled can be adapted to the process. 20. Installation according to one of the preceding claims, characterized in that the local control system can receive specifications for operating parameters of the unit assigned to it, in particular by the global control system and / or 5 to the operator. 21. Plant according to one of the preceding claims, characterized in that it comprises a maximum of five different types of comminuting units. 10 22. Plant according to one of the preceding claims, characterized in that it has a maximum of seven different types of fractionation tion units. 23. System according to one of the preceding claims, characterized in that it has a maximum of three different conditioning tion units. 24. Installation according to one of the preceding claims, characterized in that it has a maximum of 15 different types of units, which are controllable by the local control systems and by the global control system. 25. Installation according to one of the preceding claims, characterized 25 indicates that it has a maximum of two types of crushing units. 26. Plant according to one of the preceding claims, characterized in that it only one sort of crushing 30 units. 27. Plant according to one of the preceding claims, characterized in that it comprises a maximum of two types of fractionation units. 28. Plant according to one of the preceding claims, characterized in that it has only one type of fractionation units. 5 29. Plant according to one of the preceding claims, characterized in that it comprises a maximum of two types of conditioning units. 30. Plant according to one of the preceding claims, characterized in that it has only one type of conditioning units. 31. Plant according to one of the preceding claims, characterized in that a type of comminution unit is a Shearing device and in particular a roller mill is. 32. Plant according to one of the preceding claims, characterized in that a variety of crushing unit a 20 baffle and in particular an impact dissolver is. 33. Plant according to one of the preceding claims, characterized in that a sort of fractionating unit is a screening device. 25 34. Plant according to one of the preceding claims, characterized in that a variety of fractionation unit is an air separation device. 35 35. An installation according to any one of the preceding claims, characterized in that a sort of fractionating unit is a device operating on the centrifugal principle and in particular a cyclone. 36. Installation according to one of the preceding claims, characterized in that at least some of the units and conveyor lines each have sensors of their respective local control system. 5 37. Installation according to one of the preceding claims, characterized in that all units have a sensor. 38. Installation according to one of the preceding claims, characterized in lo lo at least some of the crushing units, fractionation units, conveyor lines and conditioning units each have actuators of their respective local control system. i5 39. Installation according to one of the preceding claims, characterized in that at least some of the crushing units, fractionation units, conveyor lines and conditioning units each have actuators of the global control system. 20 40. Plant according to one of claims 36 to 39, characterized in that each crushing unit, fractionation unit, conveying path and conditioning unit at least one sensor of their respective local control system 25 has. 41. Plant according to one of claims 36 to 39, characterized in that each crushing unit, fractionation unit, conveying section and conditioning unit at least 30 least one actuator of their respective local control system has. 42. Installation according to one of claims 36 to 39, characterized in that at least a major part of the crushing Units, fractionation units, conveyor lines and conditioning units has at least one sensor of the global control system. 43. Plant according to one of claims 36 to 39, characterized in that at least a large part of the crushing units, fractionation units, conveyor lines and conditioning units has at least one actuator of the global control system. 10 44. A method for controlling a process for processing cereals, in particular in a plant according to one of claims 1 to 43, using ^ a global regulatory strategy for at least one-fifth of the units of the investment; and > a local regulatory strategy for at least one unit and at most a large part of the units of the facility. 45. The method of claim 44, characterized in that the global control strategy uses a set of global policies. 46. The method of claim 44 or 45, characterized in that the global control strategy outputs local defaults for a local control strategy. 47. Method according to one of claims 44 to 46, characterized in that the operator specifies requirements for the global regulation 30 strategy and / or for the local regulatory strategy. 48. The method according to any one of claims 44 to 47, characterized in that the local control strategy uses a group of local guidelines. 5 49. The method according to any one of claims 44 to 48, characterized in that the local control strategy receives specifications for operating parameters of its associated unit. 50. The method according to any one of claims 44 to 49, characterized in that the global control strategy operates continuously, with measured variables being constantly recorded, in particular before, during and after their change. 51. Method according to claim 50, characterized in that the global control strategy comprises the simultaneous, in particular coupled, regulation of several parameters. 52. The method according to any one of claims 44 to 51, characterized in that the local control strategy discretely or 20 operates discontinuously, wherein measured variables are detected before and after their change, in particular only in a first stationary state before and in a second stationary state after its change. 53. The method as claimed in claim 52, characterized in that the local control strategy comprises the simultaneous, in particular coupled, regulation of several parameters. 54. Method according to one of claims 44 to 53, characterized in that the local control strategy comprises the disclosure of information relating to at least one unit to the global control system. 55. The method according to claim 54, characterized in that the information comprises the degree of fulfillment of local specifications from the global control strategy to the local control strategy. 56. The method according to any one of claims 44 to 55, characterized in that the global control strategy and / or the local control strategy comprises the disclosure of information to a plant operator. 57. The method according to any one of claims 44 to 56, characterized in that in at least a part of the sensors, the detection accuracy is adapted to the current requirements of the control strategy. 58. The method according to any one of claims 44 to 57, characterized in that a sensor of a local control system receives a start signal or a wait signal from the global control system, from another local control system or from an actuator. 59. The method according to any one of claims 44 to 58, characterized in that the temporal courses of the global regulatory strategy and local regulatory strategies are logged and recorded. 60. The method according to any one of claims 44 to 59, characterized in that measured values and / or other sensor information for detecting a system malfunction or a system error can be used. 61. The method according to claim 60, characterized in that the measured values and / or other sensor information for diagnosis a plant malfunction or a plant failure can be used. 62. The method according to claim 60 or 61, characterized in that upon detection and possibly diagnosis of a system malfunction or a system error, the global control system and / or the local control system takes special measures. 63. The method according to claim 62, characterized in that, depending on the extent of the system malfunction or system error as a special measure, one of the following measures are taken for at least part of the system: ^ further regulation of the faulty part of the plant or of the entire plant taking into account the fault; > only controlling the plant; > Stopping the system.