SK8195Y1 - Carcass damage detector in the steel-cord conveyor belt - Google Patents

Abstract

Carcass damage detector in the steel-cord conveyor belt with magnetic field sensing sensors due to damage to the carcass is comprised of the first damage sensor (1) and the second damage sensor (2) which are located above the conveyor belt (7) in succession in the direction of movement of the conveyor belt (7), a speed sensor (6) which contacts the conveyor belt (7) and the evaluation unit (4) which is conected with the first damage sensor (1) with the second damage sensor (2) and with speed sensor (6) wherein a conductors (5) are connected to the evaluation unit (4) for transmitting information about the damage of the carcass (3) in the steel cord conveyor belt (7).

Description

Technical field

The technical solution belongs to the electrical engineering, the area of construction of sensors of non-electric quantities, and it concerns the construction of the sensor and the method of evaluation of the signal from the sensor for the more sensitive detection of skeletal damage in the steel-cord conveyor belt.

BACKGROUND OF THE INVENTION

The steel-cord conveyor belt is a rubber belt reinforced with a steel wire frame. It is suitable for transporting material over long distances in difficult working conditions in open-cast or deep mines, quarries, landfills, power plants, limestones, steel mills and the like. The belts need to be monitored to prevent accident and subsequent shutdown of production equipment or damage to technology. The belt damage is different. Some relate to the rubber layer, other to the rubber-reinforcement connections and others to the metal reinforcement itself.

Several non-destructive methods and their associated sensors are used for monitoring (http://www.saimh.co.za/beltcon/beltcon7/paper716.html):

1. Inductive sensors

2. Reluctance sensors

3. Inductive voltage sensors

4. Eddy current sensors

5. Radiography

6. Ultrasonic sensors

Methods for monitoring the change in the magnetic field are used to diagnose damage to the steel-cord reinforcement forming the carcass of the belt. Sensors based on different principles (inductance, reluctance, induced voltage and eddy current sensors) have been developed for this purpose. Each of these sensors has a different sensitivity to detect different types of skeletal damage. At the same time, the signal from the sensor contains noise caused by unevenness of the steel wire, mechanical oscillation and electrical disturbance. Current digital signal processing allows implementation of algorithms that can increase the sensitivity of the sensors used so far.

The essence of the technical solution

The essence of the technical solution for the detection of skeletal damage in steel-cord conveyor belt with increased sensitivity is to place two identical damage sensors behind one another in the direction of belt movement and signal processing by correlation. Damage sensors are located near the belt and are sensitive to magnetic field changes caused by damage to the belt frame. The signals from the damage sensors are routed to an evaluation unit whose output signal is generated by calculating the correlation between the input signals. To calculate the correlation, a time shift between the signals from the damage sensors is required, which is determined from the speed of the belt measured by the speed sensor and from the distance between the damage sensors. The output signal from the evaluation unit responds to the damage to the belt frame and has an increased signal / noise ratio from the signals from the individual damage sensors. The increased sensitivity of the detector means a better ability to detect belt skeleton damage.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a skeleton damage detector assembly in a steel-cord conveyor belt with two damage sensors. Figure 2 shows the waveforms of the two damage sensors and the waveform of the output signal from the evaluation unit.

EXAMPLES

The high sensitivity steel-cord conveyor belt detector shown in Figure 1 consists of a first damage sensor 1, a second damage sensor 2, a speed sensor 6, and an evaluation unit 4 from which the line 5 extends. The first damage sensor 1 and the second the damage sensor 2 is positioned above the conveyor belt 7 in succession in the direction of travel of the conveyor belt 7. The speed sensor 6 contacts the conveyor belt 7. The signals from the first damage sensor X, the second damage sensor 2

The first damage sensor 1 and the second damage sensor 2 are sensitive to a change in the magnetic field due to damage to the frame 3. The conveyor belt 7 with the damaged spot in the frame 3 is moved under the first sensor. ! and then under the second damage sensor 2. The change of the signal from the second damage sensor 2 is offset in time compared to the signal from the first damage sensor 1. The amount of time shift is determined by the speed of the conveyor belt 7 and the distance between the first damage sensor 1 and the second damage sensor 2. The output signal from the evaluation unit 4, which is led through the line 5 to the master system, is generated by calculating the correlation between the signal from the first sensor! and the time shifted signal of the second damage sensor 2. 2 shows the waveform 8 of the signal from the first sensor! and the waveform 9 of the signal from the second damage sensor 2. The signals are loaded with noise and the change due to damage is noticeable. The waveform 10 in Figure 2 is generated by calculating the correlation between the time-shifted waveform 8 and the waveform 9. The change due to damage is significant during 10.

Industrial usability

Belt conveyors are commonly used in industry. A part of the conveyor operation is regular inspection of the conveyor belt. It is important to detect damage to the belt before tearing it and to estimate when the belt needs to be replaced. Increased accuracy of the carcass damage detector in the steel-cord conveyor belt can refine the belt condition estimate, thereby providing a longer time between replacements. More accurate fault diagnosis can be used to locate a repair location, thereby extending belt life.

Claims (1)

A skeleton damage detector in a steel-cord conveyor belt with sensors sensitive to magnetic field change due to skeletal damage, characterized in that it consists of a first 5 of a damage sensor (1) and a second damage sensor (2) located above the conveyor belt (7) in succession in the direction of travel of the conveyor belt (7), from a speed sensor (6) which contacts the conveyor belt (7); an evaluation unit (4) which is connected to the first damage sensor (1), the second damage sensor (2) and the speed sensor (6), and to the evaluation unit (4) is connected a line (5) for transmitting damage information (3) ) in the steel-cord conveyor belt (7).