Session: 02-01-01: Product and Process Design

Paper Number: 140116

140116 - Development of Wireless Crawler Robot for Piping Inspection 

At JFE Steel’s integrated steel works, the combustible gases generated by coke ovens, blast furnaces and LD converters are utilized as fuel gases in the works. Each works has about 100 km of combustible gas pipelines.

Impurities such as tar and water vapor contained in these combustible gases agglomerate in the pipe, generating drain. These drain causes internal corrosion in stagnant area.

Serious accidents such as leakage of combustible gases may occur due to pipe corrosion and wall thinning. Monitoring and management of corrosion and thickness reduction are performed to prevent such accidents. Generally, combustible gas pipes are inspected by ultrasonic thickness meter, but the inspection area is limited, the cost of constructing temporary scaffolding is high, and the workload is heavy due to work in high places. Therefore, a wireless crawler robot is developed to expand the pipe inspection area and reduce the inspection workload.

In this study, a completely new inspection robot is developed referring to the wired robot for piping inspection "Scan-WALKER^TM" developed by JFE Steel in the past. The sensor was developed targeting pipes with a thickness of 8 to 12 mm, which is the typical wall thickness of combustible gas pipes in steel works, with the aim of detecting a 40 % reduction of wall thickness. To realize wireless inspection, magnetic eddy current testing with a permanent magnet was selected. Other merit is below, power consumption is small and a couplant is not necessary for inspections. An evaluation test in the laboratory using a magnetic eddy current sensors succeeded in detecting inner surface defects with a thickness of more than 40 %.

The robot is equipped with magnetic wheels and magnetic crawlers to enable stable travel on large-diameter steel pipes. The device is held securely on the pipe surface by the magnetic force of the wheels and is moved by the magnetic crawlers. The robot is also equipped with a special structure that can adjust the lift-off, which is the distance between the magnetic eddy current sensor and the pipe surface, to enable travel and inspection of pipes with diameters of 500 mm or more.

A prototype robot was set on an existing combustible gas pipe (diameter: 1 200 mm) in the steel works. The robot was controlled and detected defects by wireless operation. Driving operation commands were transmitted from an operator on the ground by wireless to control the robot on the pipe. In this test, the robot traveled on the pipe in an arbitrary straight line on the pipe, and the pipe wall thickness/corrosion inspection was carried out successfully.

In the future, test operation using a robot will be carried out in each of JFE Steel’s steel works to advance preparations for practical operation.

Presenting Author: Yuta Tokumoto JFE Steeel Corporation

Presenting Author Biography: 2016年よりJFEスチール株式会社鉄鋼研究所技術研究員。 製鉄所向け多関節ロボットや自走式ロボットの開発に従事。 これまでのプロジェクトでは、製鉄所向け機械加工・ガス切断自動ロボットを開発し、JFEスチールの一貫製鉄所に導入した。 ロボットの開発により、製鉄所における重作業を省力化することを目標としている。

Authors:

Yuta Tokumoto JFE Steeel Corporation
Yuji Nishizawa JFE Steel corporation
Emu Matsufuji Kanagawa