Steel wire ropes are being used in many different hazardous industrial facilities, for example in lifting, drilling, mining and so on. The most dangerous types of rope defects – corrosion, abrasion, wire breaks, can be detected by means of magnetic rope testing. In this respect the purpose of magnetic rope testing consist in: 1. Preventing accidents caused by rope breakage, 2. Prolonging of rope service time according to its actual condition. It has approved itself as a reliable method of steel rope nondestructive testing, at the same time there are restrictions in its application, caused by the necessity of qualified staff to fulfill inspection operations and to interpret inspection results. At the same time monitoring of rope technical condition is critically important for some industrial facilities, such as drilling rigs or hoists of melting cranes, mine hoists. Automated monitoring of rope technical condition offers a solution of this problem. To build an automatic system of rope condition monitoring an automated rope tester Intros-Auto was developed. The rope tester consists of magnetic head (MH) placed at the rope and control and display unit located at operator console. It can perform both as a standalone instrument and as a part of computerized information system. Operator directly or remotely starts inspection procedure and after its completing get information about rope condition in simple and unambiguous manner (displayed according to traffic lamp principal “green/yellow/red”). If necessary detailed results analysis is possible after downloading of inspection results. For monitoring system it is important to ensure high reliability and robustness, and at the same time be easy in use. To enable an automatic data interpretation it should ensure high confidence and repeatability of measurement results and low susceptibility to external disturbances of different art. The monitoring system should confirm with ISO4309 (International standard. Cranes – Wire ropes – Care and maintenance, inspection and discard), meet the requirements of ingress protection IP65 or higher and be explosion proof, if necessary. Intros-Auto rope monitoring system was successfully implemented at drilling rigs of different oil and gas service companies, where it is used to check a rope condition at the beginning of each working shift. Main deterioration mechanism of hoist ropes consists in appearance of wire breaks and formation of their clusters. In this regard main task of hoist rope monitoring consists in detection of wire breaks and their clusters and estimation of quantitative characteristics of them. So the Intros-Auto monitoring system has two different local faults measuring channels (Halls and coils), that increase reliability of faults detection. Estimate confidence for wire breaks in clusters plays a key role for applicability of the system at a specific industrial facility, so it should be investigated.
Egor Dyskin (Thu,) studied this question.