Method for detecting and removing buildup on a component, system and computer program

Abstract

In a method for operating a system, a first vibration is imparted to a component of the system and the first vibration of the component is detected by a sensor. The sensor generates a sensor signal for transmission to a control device, which analyzes the sensor signal and determines whether a buildup is present on the component based upon the analysis of the sensor signal. A second vibration is imparted to the component to remove the buildup when the buildup has been detected.

Claims

1. A method for removing buildup from a component, said method comprising: imparting a first vibration to an exterior surface of a component, said component subject to a buildup on an interior surface of said component, said component comprising a hopper, or a grinding tube of a mill; detecting the first vibration of the component by a sensor operably connected to the exterior surface of the component; providing a sensor signal from the sensor to a control device; analyzing the sensor signal by the control device; detecting whether the buildup is present on the interior surface of the component based upon analysis of the sensor signal; and imparting a second vibration to the exterior surface of the component to remove the buildup on the interior surface of the component when the buildup on the interior surface of the component has been detected, wherein the second vibration is caused by impulses imparted to the component with a continuous increase in frequency of the second vibration as a function of time such that a time interval between said impulses decreases, wherein the continuous increase in the frequency of the second vibration results in excitation of resonance frequencies of the component.

2. The method of claim 1, wherein the sensor determines a frequency, an amplitude and/or a phase of the first vibration and provides the sensor signal based on the frequency, amplitude and/or phase.

3. The method of claim 1, wherein the first and second vibrations are imparted by an excitation unit, an amplitude of the first vibration being lower than an amplitude of the second vibration.

4. The method of claim 1, wherein the first vibration is excited by a first excitation unit and the second vibration is excited by a second excitation unit.

5. The method of claim 1, wherein a presence of the buildup is determined based on a variance in a Fourier spectrum of the sensor signal.

6. The method of claim 1, wherein at least one of the first vibration and the second vibration is imparted at a frequency which increases from 0.1 Hz to 1 kHz.

7. The method of claim 1, wherein at least one of the first vibration and the second vibration is imparted at a frequency which increases from 1 to 50 Hz.

8. The method of claim 1, wherein the first vibration is caused by impulses imparted to the component.

9. The method of claim 4, wherein the first excitation unit and/or the second excitation unit impart the first and second vibrations, respectively, to the component at a resonance frequency of the component.

10. A computer program for removing buildup from a component, said computer program embodied in a non-transitory computer readable medium, wherein the computer program, when loaded into a processor unit and executed by the processor unit, causes the processor unit to perform the steps of: imparting a first vibration to a component, said component subject to a buildup on an interior surface of said component, said component comprising a hopper or a grinding tube of a mill, detecting the first vibration of the component by a sensor operably connected to the exterior surface of the component, providing a sensor signal by the control device, detecting whether the buildup is present on the interior surface of the component based upon analysis of the sensor signal, and imparting a second vibration to the exterior surface of the component to remove the buildup on the interior surface of the component when the buildup on the interior surface of the component has been detected, wherein the second vibration is caused by impulses imparted to the component with a continuous increase in frequency of the second vibration as a function of time such that a time interval between said impulses decreases, wherein the continuous increase in the frequency of the second vibration results in excitation of resonance frequencies of the component.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention will now be presented and explained in more detail with reference to accompanying drawings. The features shown in the figures may be combined by persons skilled in the art to produce new embodiments without departing from the invention.

(2) FIG. 1 shows a hopper with buildup,

(3) FIG. 2 shows a grinding tube,

(4) FIG. 3 shows an exemplary process diagram,

(5) FIG. 4 shows an impulse timing sequence, and

(6) FIG. 5 shows a resonance curve.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(7) FIG. 1 shows a hopper 15. The hopper 15 has a buildup 3 on its first surface 5a. The first surface 5a corresponds to the inward facing surface of the hopper 15. The hopper 15 has a sensor 11 on the second surface 5b. An excitation unit 9 is disposed facing the second surface 5b of the hopper 15. The excitation unit 9 is used to excite vibrations of the hopper 15. The vibrations are detected by the sensor 11 in their frequency and amplitude. The sensor 11 provides a sensor signal to the control device 13. The sensor signal contains the information concerning the amplitude and frequency of the vibration.

(8) The control device 13 is used to evaluate the sensor signal. On the basis of the sensor signal, the control device 13 can be used to determine whether there is any buildup 3 on the first surface 5a of the hopper 15.

(9) The excitation unit 9 has a plunger 9a. The plunger 9a is used to excite a first vibration of the hopper 15. The first vibration is used to determine whether a buildup is present. The first vibration is preferably excited by one or more impulses imparted to the hopper 15.

(10) If a buildup is detected by the control device 13, it is removed from the surface of the hopper 15 by means of the excitation unit 9. For this purpose, the hopper 15 is excited to a second vibration using impulses. The time period dt between the respective impulses can be varied. The time period dt is preferably selected such that the second vibration corresponds to the resonance Res of the hopper 15 having the buildup 3.

(11) The excitation unit 9 is positioned in such a way that the plunger 9a excites the hopper to the second vibration in the region of the buildup.

(12) In FIG. 1, the component 1, 15 is designed as a hopper 15. In FIG. 2, the component 1, 15 is designed as a grinding tube 1.

(13) FIG. 2 shows a grinding tube 1. The grinding tube 1 is part of a tube mill. The grinding tube 1 has a buildup 3 in its interior. The buildup 3 is in particular a frozen charge. The grinding tube 1 has a casing 5, wherein the casing 5 has the buildup 3 on its (inward-facing) second surface 5a. The grinding tube 1 has the sensor 11 on the second surface 5b. The sensor is used to determine the first vibration, in particular the amplitude and/or frequency of the first vibration.

(14) The grinding tube 1 is rotated about its axis of rotation 6 by a drive (not shown). The rotation of the grinding tube 1 about its axis of rotation 6 is indicated by the curved arrow.

(15) If a buildup 3 is present as a frozen charge, no vibration due to movement of the charge in the grinding tube 1 is detected when the grinding tube is rotated.

(16) The sensor is used to determine the frequency and/or amplitude of the first vibration.

(17) Without rotation of the grinding tube 1, the first vibration can alternatively or additionally be excited by means of the excitation unit 9.

(18) The excitation unit 9 is advantageously disposed such that the plunger 9a excites the vibration on one of the side plates 7 of the grinding tube 1.

(19) If a buildup 3 is present, the control device 13 causes the excitation unit 9 to impart a second vibration to the grinding tube 1, in particular by means of impulses. The second vibration is likewise excited by impulses applied to the side plates 7. The second vibration is excited by means of impulses. A time period dt elapses between the respective impulses.

(20) FIG. 3 shows an exemplary process diagram. In a first step V1, the sensor 11 provides the sensor signal. The sensor signal is analyzed in a second step V2. The analysis is preferably carried out using a fast Fourier transform FFT. The fast Fourier transform FFT provides a frequency spectrum of the first vibration. The frequency spectrum usually gives indications of the presence of buildup 3.

(21) In the third step V3, an analysis Ana is used to determine whether a buildup is present. In addition, the analysis Ana can be used to determine the particular resonance frequency of the component 1, 15 having the buildup.

(22) Based on the analysis Ana, the excitation unit 9 is activated in a fourth step V4. The excitation unit 9 excites a second vibration of the component 1, 15, in particular of the respective surface 5a, 5b of the component 1, 15.

(23) Alternatively, in the first step V1, a counterforce or a countertorque can be also determined by the sensor 11. The presence of a buildup 3 can be inferred from a change in the counterforce or countertorque.

(24) FIG. 4 shows a timing sequence of the impulses KF over time t. The impulses are used to excite the first and/or the second vibration. It is shown that the length of time dt between the respective impulses KF decreases. A resonance Res can be excited by the decrease in the respective length of time dt between the impulses KF, wherein the frequency of the resonance Res does not initially need to be known. Due to the decreasing time period dt, buildup can be removed from a surface 5a, 5b of the component 1, 15 even without an analysis Ana, in particular by exciting a resonance.

(25) FIG. 5 shows a resonance curve. The resonance curve shows that the effect W of the second vibration on the buildup 3 increases towards a resonance Res. When the resonance Res is present, the effect W of the second vibration is at its strongest, i.e. a buildup 3 is best removed. Accordingly, it is advantageous for the time dt between the impulses to be made to decrease, as the resonance Res of a component 1, 15 is normally excited in this way.

(26) In summary, the invention relates to a method and a device for detecting and removing a buildup 3. The first vibration, which is excited e.g. by an excitation unit 9, is detected using a sensor. The sensor 11 provides a sensor signal, wherein the sensor signal is analyzed in a control device 13 for the presence of a buildup 3. If the analysis Ana indicates a buildup 3, a second vibration is imparted to the component 1, 15 by means of the excitation unit 9. The second vibration is used to remove the buildup 3. By removing the buildup 3, the component 1, 15 or the system comprising the component 1, 15 can be operated for longer without maintenance.