At its site in Stade, Aluminium Oxid Stade GmbH produces a highly pure aluminium oxide which is in demand throughout the world. The production capacity is approx. 1,050,000 tonnes per year. The modern production facilities and constant optimisation of the production processes require the latest technology and qualified personnel.

Aluminium Oxid Stade GmbH, along with the support of its partners, is constantly improving its products and processes, including in the joint development of an ultrasonic inspection robot with INSPECTOR SYSTEMS.

Ultrasonic inspection robot - monitors pipe reactor for aluminium oxide production
Ultrasonic inspection robot - monitors pipe reactor for aluminium oxide production
Ultrasonic inspection robot - monitors pipe reactor for aluminium oxide production

This ultrasonic inspection robot for checking pipe reactors with an inspection length of up to 200 m allows reductions in the wall thickness to be distinguished in terms of their position and magnitude on the inside or outside of the pipe wall.

It mainly comprises a driving pig for pushing through the inspection robot with water pressure, an inspection element with eight ultrasonic sensors and automatic position regulation, an electronic housing and a 250 m long special cable for connecting the inspection robot to an evaluation unit.

The inspection robot is designed so that it can traverse straight DN150 and DN200 pipe sections as well as dogleg bends at the start and end of the pipeline.

The principal task of the ultrasonic robot is to determine the wall thickness at the points in the lower area of the relevant pipe reactors that are under most stress.

For this a special position-regulated ultrasonic unit with a total of eight inspection heads was developed. The eight inspection heads are equipped with a 4 x 1 mm line focus and arranged in such a way that continuous data recording of +/- 16 mm in the lower pipe area can be guaranteed. The interval between the measuring points in the direction of travel is 1 mm.

The accuracy of the measured wall thickness values is +/- 0.2 mm with a wall thickness range of approx. 2 to 12 mm.

The pressure resistance of the ultrasonic inspection robot and inspection heads is approx. 10 bars. This is necessary as the pressure of the water pump required for pushing through the robot can attain these values.

The ultrasonic inspection robot is made completely of stainless steel so that any leaching residues in the individual pipe reactions cause no damage to the inspection robot.

The ultrasonic data from the individual inspection heads are processed directly in the electronic module of the inspection robot with the aid of two 4x boosters. They can then be transmitted via the 250 m special cable for evaluation. The cable itself consists of eight coaxial cables for signal transmission from the inspection heads and various copper wires for data communication and power transmission. It is extremely tear-resistant and is specially designed for this application.

The control/evaluation unit controls the functions of the inspection robot and shows the individual wall thickness measurements in graphic form. An Olympus Omniscan is used as the ultrasonic evaluation unit. For superordinated visual presentation the TomoView evaluation software is used which shows a colour C-image of all recorded wall thickness measurements on a laptop.