METHOD OF MONITORING HIGH-PRESSURE ROLLER PRESS

Abstract

The invention relates to a method for monitoring the wear state of the rolling surfaces of a high-pressure roller press in the course of comminuting, compacting, or briquetting material. The roller press has two rotationally driven press rollers, between which a rolling gap is formed with a gap width that can be modified during operation. One of the press rollers is designed as a stationary roller, and one of the press rollers is designed as a loose roller, wherein the loose roller can be positioned against the stationary roller via a force generating means with a gap width which can be modified during operation, and the outer diameter of the press rollers or the is reduced due to wear during operation. The method is characterized in that the position of the loose roller is recorded as a function of time using at least one position sensor, the position data is stored on a computer, and the wear state of the rollers is ascertained from the measured position data using an algorithm.

Claims

1. A method of monitoring a wear state of roll surfaces of a high-pressure roller press in the course of comminuting, compacting or briquetting material, where the roller press has two rotatably driven press rolls forming a roll gap whose gap width is variable during operation, one of the press rolls is a fixed roll and one of the press rolls is a movable roll and the movable roll can be adjusted relative to the fixed roll by an actuator with a variable gap width during operation, and an outer diameter of the press rolls or rolling surfaces thereof decrease during operation by wear, the method comprising the steps of: recording the position of the movable roll is as a function of time with at least one position sensor position data are stored on a computer, and determining the wear state of the roll or of the rolls or rolling surfaces thereof using an algorithm from the measured position data.

2. The method according to claim 1, further comprising the step of: generating a prediction for a remaining service life of the roll or roll surface with an algorithm from the measured position data.

3. The method according to claim 1, further comprising the step of: measuring the position of one or more bearing points of the movable roll with one or more position sensors relative to a stationary press frame and generating position data representing the measured position.

4. The method according to claim 1, further comprising the steps of: storing the position data as raw data on an edge computer on or adjacent the roller press and connected to the sensors as an analysis computer, evaluating the raw data are evaluated on the analysis computer with an analysis algorithm and thus generating characteristic data for the wear state and storing these characteristic data are stored on the analysis computer, transmitting the characteristic data from the analysis computer to at least one terminal via a wireless network and displaying or further the characteristic data on the terminal.

5. The method according to claim 1, further comprising the step of: recording the raw data at a high sampling rate of more than 50 Hz and storing the raw data on the analysis computer.

6. A plant for comminuting, compacting or briquetting material according to a method according to claim 1, comprising at least a roller press having two rotatably driven press rolls, forming a roll gap whose gap width is variable during operation, one of the press rolls being a fixed roll and one of the press rolls being a movable roll and the movable roll being adjustable relative to the fixed roll by an actuator with a variable gap width during operation, one or more position sensors that can record position data of the movable roll as a function of time and store the position data d on a computer, means for determining the wear state of the roll/rolls or the roll surfaces thereof using an algorithm from the measured data and generating a prediction for a remaining service life of the jacket.

7. An installation according to claim 6, further comprising: an edge computer located locally at the roller press and connected to the position sensors as an analysis computer.

8. The installation according to claim 6, further comprising an analysis router connected to the computer and a terminal accessed via the router at a portal connected to the router via a VPN connection.

9. The installation according to claim 6, wherein the press rolls each have a roll core and a jacket on the roll core and forming a roll outer surface.

Description

[0034] The invention is explained in more detail below with reference to drawings showing embodiments by way of example. Therein:

[0035] FIG. 1 is a schematic greatly simplified diagram of a system according to the invention with a roller press,

[0036] FIG. 2 is a view of the movable roll position and the wear state for maintenance prediction.

[0037] FIG. 1 shows, for example, a system for monitoring a condition of a high-pressure roller press 1 is intended, for example, for comminuting granular material, alternatively also for compacting or briquetting material. The roller press has a press frame 2 and two press rolls 3a and 3b that are rotatably mounted in the press frame 2 and are driven for rotation in opposite directions. A roll gap whose gap width is variable during operation is formed between the press rolls. This is because one of the two press rolls is designed as a fixed roll 3a mounted in a stationary manner in the press frame 2, and the other press roll is designed as a movable roll 3b, and this movable roll can be urged toward the fixed roll 3a via biasing means, for example via hydraulic cylinders 4, so that the gap width of the roll gap can change during operation. However, the roll gap is adjusted automatically during operation due to the positioning of the movable roll with respect to the fixed roll until a certain pressure is exerted between the rolls. Each of the two press rolls 3a and 3b has a roll surface that is subject to wear. In one embodiment, each roll 3a and 3b can have on the one hand a driven roll core and on the other hand a jacket (for instance tubular) on the roll core, which jacket, for example, is provided with a wear-resistant surface. Details are not shown in the figures.

[0038] Such a roller press 1 can be connected in a conventional manner to a programmable logic controller or PLC 5 that in turn can be connected to a higher-level plant controller or control room 6. The operation of the roller press 1 can be controlled and monitored in a known manner via the guide plate 6. For this purpose, the PLC 5 can be connected on the one hand to the drives of the roller press and on the other hand to different sensors.

[0039] In this embodiment, however, as an alternative or in addition to the programmable logic controller 5, a special computer is provided, namely an edge computer as an analysis computer 7 that is hard wired via one or more connecting cables 8 to sensors 9 of the roller press. This edge computer or analysis computer 7 is locally stationary in the immediate vicinity of the roller press. Operating data registered by the sensors 9 are stored as raw data on this analysis computer 7. For this purpose, the sensors 9 may be provided with (additional) measuring devices or cards 10, with which the analog measurement data are converted into digital operating data R. Preferably, optical connecting cables, for example optical waveguides for particularly fast data transmission for the connection 8 of the measuring card 10 to the analysis computer 7, are used. The analysis computer 7 is provided as an edge computer with considerable memory 11, processors 12 and specially designed algorithms 13 for the analysis and evaluation of the operating data. Several memories 11 for redundant data storage are preferably provided in the analysis computer 7. The raw data R are stored on the analysis computer 7 and evaluated with the analysis algorithms 13 and thus characteristic data K of the roller press 1 are generated that are likewise stored on the analysis computer. According to the invention, these characteristic data K are transmitted from the analysis computer 7 via a wireless network 14, for example via the Internet, to one or more terminals 15, for example PCs, tablets, smart phones or the like. The characteristic data K can be accessed via the terminals 15. It is of particular importance here that correspondingly authorized users have access to the already evaluated characteristic data K via the terminals 15 and not to the very extensive raw data. For this purpose, the characteristic data K in the analysis computer 7 can be stored in the analysis computer 7 for example in a database as compressed data and provided in the database for online access via PC, smart phone or the like, for example for corresponding plant status displays.

[0040] In this case, the operating data R can be recorded in a conventional manner with known measuring value sensors 9 provided in any case at the roller press. According to the invention, the position of the movable roll is detected for example by position sensors for wear monitoring. In addition, further data can be determined by further sensors, namely for example the torque of a press roll or of both press rolls, the hydraulic pressure of the hydraulic cylinders for the application of the movable roll, weighing cells, temperature sensors, flow sensors or the like. The state of the roller press 1 or values of these sensors 9 can be displayed in compressed form via the terminals 15 in a simple manner, so that current machine status can be displayed. Alternatively, statistical evaluations can be queried on the terminal 15 that, however, are not generated on the terminal 15, but rather on the analysis computer 7, for example individual week reports, month reports or the like. Particularly preferably, however, interference conditions, exceptional conditions or the like can be monitored using the method according to the invention.

[0041] For this purpose, it is particularly advantageous if the operating data are recorded as raw data R at a high sampling rate of more than 100 Hz, for example more than 200 Hz and stored on the analysis computer 7. This results in extremely large amounts of data that, however, are transmitted via hard wiring directly to the local analysis computer 7 and stored there and already evaluated. From the very large quantities of data, the desired characteristic data or characteristic values K are generated by the already mentioned analysis algorithms 13 and can be accessed by the terminals 15 via the wireless network 14, for example via the Internet.

[0042] FIG. 1 shows that the computer 7 is connected for online access to a commercial-grade router 16 that, in a preferred variant, is connected to an Internet portal 18 via a VPN network or VPN connection 17. The terminals 15 consequently do not access the commercial-grade router 16 directly for a query of the evaluated characteristic data, but via the portal 18, specifically for example via secured or encrypted https connections 19. Otherwise, an additional computer or PC 21 can optionally be connected to the portal 18 via an additional VPN connection 20, so that data is not only queried via this PC for remote maintenance, but can also be accessed on the analysis computer 7 or the roller press.

[0043] It is furthermore indicated in FIG. 1 that field data F and consequently data from other components of the plant, for example a grinding system A, can also be detected at the PLC 5 and/or the computer 7, for example operating data of a sifter.

[0044] Finally, data, commands or the like can also be transmitted from the analysis computer 7 to the roller press 1 or other components of the system. For example, the evaluated characteristic data can be used for controlling the press or other machines with or without feedback.

[0045] The method according to the invention is illustrated for example with reference to FIG. 2 that shows the position of the movable roll 3b (top left) as a function of time. The absolute position of the movable roll 3b is detected by one or more position sensors. The position of the movable roll 3b relative to a stationary press frame 2 is referred to as the position of the movable roll 3b. For this purpose, position sensors 9 can be mounted at the bearing points of the movable roll, for example. In FIG. 2 the position of a bearing point as a function of time is shown at the top left. It can be seen that these raw data R are first picked up at high frequency and stored on the analysis computer 7. The latter generates therefrom the characteristic data K that are plotted in the graph at the bottom. This is a measure of the wear V of the rolling surfaces, for example of the jackets, and it can be seen that this measure increases with increasing operating time, since the working roll diameter, for example the diameter of the jacket decreases as a result of wear. If a certain upper limit value is reached, the rolling or rolling surfaces, for example the jackets, are exchanged. This can be seen by the abrupt drop at the points shown. While the raw data R actually relate to the position data, the characteristic data K are data that represent the wear state V of the rolling surface. According to the invention, there is the possibility of displaying the wear state that is plotted in FIG. 2, on the terminals 15.

[0046] Alternatively or additionally, maintenance predictions can also be made, i.e. a time at which an exchange of the rolling surface or of the rolls is required or recommended can be displayed on the terminal.