WO2012004050A1

WO2012004050A1 - Device for monitoring a conveying system using an electrode component for detecting damage to a conveyor belt

Info

Publication number: WO2012004050A1
Application number: PCT/EP2011/058522
Authority: WO
Inventors: Stefan Sostmann; Wolfram Herrmann; Tobias Wennekamp
Original assignee: Contitech Ag
Priority date: 2010-07-08
Filing date: 2011-05-25
Publication date: 2012-01-12
Also published as: EP2590883A1; DE102010017801A1

Abstract

The invention relates to a device for monitoring a conveying system (1) in a continuous and nondestructive manner, comprising at least the following components: an endlessly closed conveyor belt (2) with a supporting-side cover plate (3) and a running-side cover plate (4), each said plate being made of a polymer material with elastic properties and a mixed-in electrically conductive filler, and an embedded tension member; drums (5), idler rollers (6), and supporting structures, said components forming a material-conveying upper run (A) and a material-free lower run (B) in conjunction with the conveyor belt (2); and a monitoring system (7) for detecting damage to the conveyor belt (2). The monitoring system is provided with at least one scanning unit (8) that detects the surface of the supporting-side cover plate (3) within a material-free region and/or the surface of the running-side cover plate (4) of the passing conveyor belt (2) in a contact-free manner, said scanning unit (8) communicating with a measuring unit (9) and an analyzing unit (10), specifically with the detection of the actual values when comparing with the target values. The device according to the invention is characterized in that the scanning unit (8) is an electrode component in the context of a dielectric measuring system, said component consisting of at least one first electrode, a second electrode, and a gap which is present between both said electrodes and which comprises a medium. Said component also generates an electric field with which changes in the structure of the supporting-side cover plate (3) and/or the running-side cover plate (4) of the conveyor belt (2) can be detected.

Description

description

Device for monitoring a conveyor system using a

The invention relates to a device for continuous and non-destructive

Monitoring a conveyor system with at least the following components:

- An endlessly closed conveyor belt with a support-side cover plate and

running side cover plate each made of a polymeric material having elastic properties and a mixed electrically conductive filler and with an embedded tensile member;

- Drums, carrying rollers and shoring, wherein the aforementioned components in

Connection with the conveyor belt a material-promoting upper strand and a

form material-free bottom strand; such as

a monitoring system for detecting damage to the conveyor belt, which is provided with at least one scanning unit, the non-contact the surface of the support-side cover plate within a material-free area and / or the

Detected surface of the running side cover plate of the passing conveyor belt, wherein the scanning unit corresponds to a measuring unit and an evaluation unit, while detecting the actual values when compared with the target values.

As far as the construction of a conveyor belt is concerned, in particular the following

Patent literature referenced: DE 25 20 943 AI DE 38 01 120 AI

DE 25 32 190 AI DE 43 33 839 AI

DE 44 36 042 A1 EP 0 753 471 A1

EP 0 336 385 A1 WO 2008/034483 Al

The support-side cover plate and the run-side cover plate usually each consist of a rubber mixture containing a rubber component or a

A rubber component blend, a crosslinking agent or a crosslinking system, comprising a crosslinking agent and an accelerator, and usually further Mischingingredienien, in particular a filler and / or a

Processing aids and / or an aging inhibitor and / or a plasticizer and / or other additives (for example fibers, color pigments). The relevant

Rubber base is in particular: natural rubber (NR)

Butadiene rubber (BR)

Chloroprene rubber (CR)

Styrene butadiene rubber (SBR)

Nitrile rubber (NBR)

Butyl rubber (HR)

Ethylene-propylene rubber (EPM)

Ethylene-propylene-diene rubber (EPDM)

SBR / BR blend

NR / BR blend

Of particular importance to date is CR, which is characterized by a high resistance to fire, weathering and aging, in particular for conveyor belts used in underground mining. NR has also become more important in surface mining. Due to the vulcanization of a rubber mixture of the type mentioned above, the conveyor belt undergoes the necessary elastic properties. As embedded tension members, steel or aramid ropes running in the longitudinal direction of the conveyor belt are used, ropes made of steel being of particular importance.

In particular, in connection with steel cable conveyor belts for the purpose of slot protection in addition an embedded transverse reinforcement of synthetic cords, for example

Polyamide (PA), used (WO 2008/034483 AI). The tension member may also be a textile fabric, in particular a single- or multi-ply fabric, for example a polyester-polyamide fabric. In most cases, the leadership of a conveyor belt takes place in a conveyor system in an open form, in the context of a domed carrying roller chair.

In the last 20 years, however, the closed conveyor system has been further developed using a tubular conveyor belt. The system components are in the closed conveyor system in addition to the drums (drive drum, reversing drum), carrying rollers and shoring mostly correction rollers and a hold-down roller when closing the conveyor belt. In this regard, reference is made in particular to the following patent literature:

DE 36 06 129 AI DE 10 2009 003 552 AI

DE 36 12 765 AI EP 0 336 385 AI

DE 43 33 839 B4

Further components of a conveyor system can be a task chute within the

Obertrums, pulleys in the area of the lower strand and Fördergurtprofüe of a polymeric material, such as edge profiles, be.

Conveyor belts are heavily stressed when impacting the conveying material, for example ores. This often causes damage to the support-side cover plate of the conveyor belt, in the form of cuts, material chipping or other

Damage. These are critical for the life of the conveyor belt and must therefore be recognized as early as possible. Wear by abrasion can also in the run-side cover plate with contact with the drums and carrying rollers and possibly to other roller components, which are mentioned above, occur. In addition, in a steel cable conveyor belt, the support side and / or running side

Cover plate are slashed under extreme loads through the steel cables, the already presented Synthetic cord cross arming offers - albeit not always - sufficient slot protection. Ultimately, the train carrier at a

Continuous operation can be damaged, which can have negative effects on the tensile force of a conveyor belt. In addition to the regular visual inspection, there are various systems for

Monitoring the condition of the conveyor belt during operation of a conveyor system. An outline of the related art is given below:

- The publications DE 44 44 264 Cl, DE 197 15 703 AI and WO 02/40 384 AI

describe an approach in which the conveyor belts with conductor loops in regular

Be provided with distances whose damage is caused by electro-inductive

Measuring method can be detected. Instead of conductor loops or in

Combined with these, transponders can also be used. A disadvantage of this monitoring concept is the sensitivity of the systems to the

Operating conditions and the necessary modification of the belt structures with the

Conductor loops and / or transponders. In particular, the transponders are extremely susceptible to interference.

- The publications DE 195 39 980 AI and EP 0 787 669 Bl describe a

Monitoring device using transversely to the conveying direction in the

Conveyor belt built-in monitoring elements and identification elements, which reports both the state and the position when passing on stationary reading devices. However, this monitoring concept is very complicated in its implementation. The published patent application DE 198 40 081 A1 introduces a system for monitoring a layer subject to wear. For example, a

Ferromagnetic layer embedded in the support side and / or running side cover plate, which shields the signal of an underlying transponder, unless this layer is damaged. This monitoring concept is very complex and only applicable to specially equipped conveyor belts.

- The control of the condition of the steel cables in conveyor belts is carried out by an inductive field passed outside (DE 199 21 224 AI) or by a magnetic field (DE 10 2006 036 668 AI). The disadvantage is that hereby only damage the

Steel cable structures are detectable.

- In the monitoring of damage to the load side and / or running side

Cover plate come opto-electronic systems, in particular in the form of a line or area camera, are used, in this regard, in particular the following

Patent Literature is referenced:

DE 24 13 543 AI DE 101 29 091 AI

DE 42 40 094 AI DE 101 40 920 AI

DE 100 29 545 A1 EP 1 187 781 Bl

DE 100 48 552 A1 WO 2005/023688 A1

DE 101 00 813 A1 WO 2008/031648 A1

The extensive development work documented here underlines the increasing importance of this monitoring device. In addition to the great technical effort, however, this monitoring concept is one of

Belt surface dependent without significant contamination. For this reason, the opto-electronic system is additionally provided with a blow-off device, which, however, shows the limits of cost-effectiveness. Furthermore, a device for nondestructive inspection of a conveyor belt by means of high-energy radiation, in particular X-rays, is known, reference being made in this regard, in particular, to the following patent literature: DE 35 17 314 A1 JP 04158208 A (Patent Abstracts of Japan)

WO 2006/066519 AI JP 2000292371 A (Patent Abstracts of Japan)

The disadvantage is that in such beams for safety reasons the

Monitoring system must be integrated into a housing, which also shows the limits of cost-effectiveness.

Furthermore, the inner life of a conveyor belt, in particular the embedded steel cables, is primarily detected in this monitoring device. In the background of the above-mentioned overall problem, the object is to provide a generic device for monitoring a conveyor system, in which the damage of the support side and / or running side cover plate, in particular the support side cover plate, can be detected early and also wear-free, low maintenance and at economical as possible.

This object is achieved in that, in the context of a dielectric measuring system, the scanning unit is an electrode component consisting of at least one first electrode and second electrode and a gap between these two electrodes comprising a medium, thereby generating an electric field, by which

Changes in the structure of the support-side cover plate and / or running side cover plate of the conveyor belt can be detected.

The polymeric materials typically used in conveyor belts for the support-side and / or run-side cover plate are usually around

Elastomeric formulations on the rubber base mentioned above with a significant proportion of carbon black as a filler in the recipe. These are polymeric Materials with good conductive fillers in an insulating polymer matrix. This polymer matrix usually has a significant polarizability, as described by the dielectric constant. The dielectric constant describes how much under the influence of an electric field charges can shift within the material, for example by training and / or alignment of existing dipoles. Bringing such a material in an electric field, it causes a change in the capacitance measurable at the electrodes. The change is material-specific and depends on the amount of polarizable polymer material in the field. This effect is now exploited in the device according to the invention by passing the conveyor belt on an electric field, which is monitored continuously with respect to its capacity. Are now, for example, outbreaks or

Damage to the support-side cover plate is present, the amount of that

Polymer material changed in the electric field and you can observe this in a changed capacity in the electrical measurement.

Also, this measuring principle reacts to changes in the polymeric material,

For example, with respect to the mechanical aging, but are not expected in the conveyor belt to that extent. Here, the amount of polymeric material in the electric field is crucial for the measurement signal.

The document WO 2007/109896 AI also describes a dielectric

Measuring approach for monitoring drive belt in use, but in contrast to the device according to the invention changes in the polymeric material are tracked.

The document WO 2009/003853 A2 describes the use of the dielectric measurement of polymer materials for the tracking of aging and fatigue processes.

Regarding the arrangement of the electrode member close to the passing one

Conveyor belt are presented below three variants: - Variant I

The electrode component is arranged such that the electric field covers the entire conveyor belt width. This is preferably the case when the conveyor belt is not too wide, for example up to 1000 mm.

- Variant II

The electrode component is arranged in such a way that the electric field essentially only covers the middle region of the conveyor belt, which with respect to the support side

Cover plate is particularly affected by impact damage. For example, if the conveyor belt is 2000 mm wide, the center area is detected with a dimension of about 1000 mm. - Variant III

Large overland conveyor belts, for which monitoring is of particular importance, are generally up to 2800 mm wide. From these points of view, it is advantageous if the conveyor belt is divided into longitudinal strips. If, for example, the

Conveyor belt has a width of 2000 mm, it is divided into 20 longitudinal strips, each with a width of 100 mm. After each round this will happen

Electrode component offset by 100 mm as a scanning unit. A 2000 mm wider

Conveyor belt would then be completely recorded in 20 cycles. In this way, you can work with smaller electrode components, for example, with the dimensions of 100 x 100 mm.

Furthermore, it is advantageous if, in order to localize the damage at regular intervals, for example at a distance of 20 m, detectable elements in the

Conveyor belt are integrated, with the formation of a respective

Section mark. Each section is assigned a unique address, for example, in a number or letter sequence. The detectable element is completely embedded in the conveyor belt or attached to the belt surface. The preferred variant is the complete embedding, specifically to protect the detectable element. This detectable element consists in particular of a dielectrically active material. Examples are given in particular:

- The detectable element is a metal strip.

- The detectable element comprises a polymer matrix, preferably on the basis of the cover plate material, wherein in this polymer matrix evenly distributed small-sized metal particles, for example in powder form, are incorporated.

Further design variants of the monitoring device as well

Design forms of the Elekrodenbauteils as a scanning unit are presented in the context of the description of figures even closer.

The invention will now be explained by means of exemplary embodiments with reference to schematic drawings. Show it:

1 shows a conveyor system with an electrode component as a scanning unit, which corresponds to a measuring unit and evaluation unit.

FIG. 2 shows an annularly formed electrode component; FIG.

3 shows an electrode component in a combing construction.

Fig. 1 shows a conveyor system 1 with a conveyor belt 2, comprising a support-side cover plate 3 and a running cover plate 4 each made of a polymeric material having elastic properties, for example, a vulcanized rubber mixture based on CR, and an embedded Zuträger, for example in shape from

Steel cables. In the vulcanized rubber mixture, an electrically conductive filler in the form of carbon black is added. In the running direction (maintenance), the conveyor belt 2 is guided around a drum 5, wherein within the upper strand A, the material promotion takes place. The drum 5, which has no contact with the conveying material, is usually the drive drum. The

Reverse drum, where the conveyor belt 2 is transferred from the upper strand A in the lower strand B, with simultaneous ejection of the conveying material is not shown here. Regarding this detail is on the above-mentioned prior

Funding technology directed. The running side cover plate 4 is supported within the upper strand A and the upper strand B on support rollers 6.

The conveyor system 1 is equipped with a monitoring system 7, comprising a scanning unit 8, measuring unit 9 and an evaluation unit 10. The scanning unit 8 detects contactlessly the surface of the support-side cover plate 3 within the

Untertrums B, where no material production takes place. Since the drum 5 is also free of a material promotion, can also within this drum area the

Scanning unit can be arranged. The distance of the scanning unit 8 to the passing conveyor belt 2 is <10 mm, in particular 2 to 5 mm. This preferred small distance is in an arrangement principle of the scanning unit 8 within the

Untertrums B or within the range of the drum 5 realized.

As part of the examination of the running side cover plate, the scanning unit can be arranged both in the upper run and in the lower run. However, the arrangement of the scanning unit within the lower strand is also preferred here. In the running direction of the conveyor belt 2, in front of the scanning unit 8, for example at the position X, a brush or a scraper may still be arranged, which cleans the belt surface.

In most cases, a single scanning unit 8 is sufficient. In large-scale conveyor systems, several scanning units can be arranged at certain intervals. The conveyor system 1 can also be equipped with an additional component in the form of an audible and / or visual warning, which responds when a critical condition with regard to the damage of the support-side cover plate 3 and / or running side cover plate 4 is reached. An automatic shutdown of the conveyor system upon reaching such a critical state is possible. In this context, reference is made in particular to the prior art mentioned at the outset for the monitoring of a conveyor system by means of opto-electronic systems.

As part of the device according to the invention, the scanning unit 8 is now a

Electrode member. The electrode component is designed in terms of area so that a significant capacity of the polymer mixture in question can be measured. For example, the standard electrode according to DIN 53483 can be used.

In connection with FIGS. 2 and 3, two preferred electrode components will now be presented in more detail.

Fig. 2 shows an electrode member 11 in an annular design. The first electrode 12 forms the core and is surrounded by the sleeve-shaped second electrode 13. Between these two electrodes is an annular air gap 14. Between the two electrodes, an alternating electrical field is now applied. With a corresponding measuring electronics behind it, for example by means of a dielectric network channel, the capacitance signal and thus the dielectric constant can be evaluated. The measurement is preferably carried out at a fixed frequency. Medium frequencies of 10 to 200 kHz have proven to be ideal.

The penetration depth of the electric field in the sample can be controlled by the distance between the two electrodes to each other. With a distance of several millimeters, the penetration depth is large enough so that the field also interacts with the cover layer of the conveyor belt to be measured. The typically conveyed bulk materials are so low in their dielectricity that residues still adhering to the surface are negligible. However, it is advantageous if the presented in connection with FIG. 1 additional

Cleaning measure the belt surface is made by a running bust or a scraper.

Fig. 3 shows an electrode component 15 in a combing construction. The

Comb tips 18 of the first electrode 16 and the comb tips 19 of the second

Electrode 17 form an interdigitated electrode system to form an air gap 20 here. With such an electrode construction, the capacitance signal can be increased. Otherwise, here on in conjunction with the

Embodiment of Fig. 2 referenced.

LIST OF REFERENCE NUMBERS

(Part of the description)

1 conveyor system

2 conveyor belt

3 load-bearing cover plate

4 running side cover plate

5 drum

6 carrying rollers

7 monitoring system

8 scanning unit

9 measuring unit

10 evaluation unit

11 electrode component in an annular design

12 first electrode

13 second electrode

14 gap in the form of an air gap

15 electrode component in comb-shaped design

16 first electrode

17 second electrode

18 crest tip of the first electrode

19 crest tip of the second electrode

20 gap in the form of an air gap

A upper run

B bottom strand

X position of a brush or a scraper

Claims

claims

1. Device for continuous and non-destructive monitoring of a

Conveyor system (1) with at least the following components:

- An endlessly closed conveyor belt (2) with a support-side cover plate (3) and running side cover plate (4) each comprising a polymeric material having elastic properties and a mixed electrically conductive filler and with an embedded tensile member;

- Drums (5), carrying rollers (6) and shoring, wherein the aforementioned components in conjunction with the conveyor belt (2) form a material-promoting upper run (A) and a material-free lower run (B); and - a monitoring system (7) for detecting damage to the conveyor belt (2), which is provided with at least one scanning unit (8) contactless the surface of the support-side cover plate (3) within a material-free area and / or the surface of the running side cover plate (4) of the passing conveyor belt (2) detected, wherein the scanning unit (8) with a measuring unit (9) and an evaluation unit (10) corresponds, while detecting the actual values when compared with the desired values; characterized in that in the context of a dielectric measuring system, the scanning unit (8) is an electrode component (11, 15) consisting of at least one first electrode (12, 16) and second electrode (13, 17) and an existing between these two electrodes Gap (14, 20) comprising a medium, and thereby generates an electric field, whereby changes in the structure of the support-side cover plate (3) and / or running side cover plate (4) of the conveyor belt (2) can be detected.

2. Device according to claim 1, characterized in that the electrode component (11) is annular.

3. Device according to claim 1, characterized in that the electrode member (15) is formed in a meshing construction by the first electrode (16) and the second electrode (17) with their respective comb tips (18, 19) engage with each other.

4. Device according to one of claims 1 to 3, characterized in that the gap (14, 20) between the first electrode (12, 16) and the second electrode

(13, 17) is an air gap.

5. Device according to one of claims 1 to 4, characterized in that the

Electrode member (11, 15) in the detection of the damage of the supporting side

Cover plate (3) of the conveyor belt (2) in the region of that drum (5), where no

Or within the lower run (B) of the

Conveyor system (1) is arranged.

6. Device according to one of claims 1 to 5, characterized in that the electrode component (11, 15) is arranged such that the electric field, the entire

Belt width recorded.

7. Device according to one of claims 1 to 5, characterized in that the

Electrode component (11, 15) is arranged such that the electric field covers the central region of the conveyor belt (2).

8. Device according to one of claims 1 to 5, characterized in that a displaceable electrode component (11, 15) detects a longitudinal strip system of the conveyor belt (2).

9. Device according to one of claims 1 to 8, characterized in that the

Electrode component (11, 15) at a distance <10 mm to the passing

Conveyor belt (2) is arranged.

10. Device according to claim 9, characterized in that the electrode component (11, 15) at a distance of 2 to 5 mm to the passing conveyor belt (2) is arranged.

11. Device according to one of claims 1 to 10, characterized in that the

Electrode component (11, 15) operates at a fixed frequency.

12. Device according to claim 11, characterized in that the electrode component (11, 15) operates at a frequency of 10 to 200 kHz.

13. Device according to one of claims 1 to 12, characterized in that

for the purpose of locating the damage periodically detectable elements in the conveyor belt (2) are integrated, forming a respective section mark.

14. Device according to claim 13, characterized in that the detectable

Element is completely embedded in the conveyor belt (2) or attached to the belt surface.

15. Device according to claim 14, characterized in that the detectable

Element consists of a dielectrically active material.

16. Device according to one of claims 1 to 15, characterized in that in

Running direction of the conveyor belt (2) in front of the scanning unit (8) a brush or a scraper is arranged.