Robotization of continuous casting of steel

Introduction

The result of the 4th industrial revolution should be fully automated production. Robotization of workplaces and a complete departure from manual labor is the minimum that needs to be done along the way.

Historically, robots began to appear in the steel industry in the early 2000s as a development of manipulators for temperature measurement and liquid metal sampling. Initially, the only goal was to provide an increased level of security when performing these operations. Over time, robots were taught new functions that required increased fidelity. Modern robotic complexes already have multi-functionality and adaptability to changing environmental conditions of the production environment.

Robotization of continuous casting of steel

A large area for robotization of production is the section for continuous casting of steel. Casting steel is one of the most difficult and dangerous professions in metallurgy. The specificity of the profession implies the performance of work in extreme production conditions – constant interaction with hot metal, high dynamic loads. But the “time of heroes” remains in the past and the labor market is forced to adapt to the requirements of a new generation of workers. Modern working conditions provide absolute safety and comfort in the workplace. Highly qualified metallurgists should be engaged in the optimization and development of technological processes, and robots will take care of heavy and dangerous technological operations.

The technologies that exist today make it possible to completely replace the manual labor of steel pourers and, thus, make a great contribution to the development of industrial safety in production.

In total, 3 jobs for steel pourers can be allocated at the UNRS (see Fig. 1):

1. Ladle platform

Technological operations performed

  • Measuring the temperature of the metal in the tundish

  • Measurement of hydrogen concentration in metal

  • Measurement of hydrogen concentration in metal

  • Sampling of metal from the tundish

  • Supply of slag-forming and heat-insulating mixtures to the tundish

  • Oxygen cleaning of the steel tap hole

  • Installing/removing the protective tube

2. Platform on the back side of the ladle stand

Technological operations performed

  • Installing a hydraulic cylinder on a sliding gate

  • Connection of working media and electrical signals (argon, air, slag detector)

3. Filling area

Technological operations performed

  • Replacement of submersible nozzles

  • Operations with feeders (“feeders”) of the SCO feeder

  • Automatic glass warmer

Rice.  1 Range of robotic solutions for continuous casting of steel
Rice. 1 Range of robotic solutions for continuous casting of steel

Robotization drivers are the improvement of the following production indicators:

1. Increased workplace safety

Robotization completely eliminates the interaction of people with harmful and dangerous production factors (the working area is equipped with stationary protective fences with lockable doors, as well as an emergency stop system of categories 0 or 1 with a maximum stop time of 1.1 seconds). All risks associated with erroneous actions of personnel such as:

  • damage to the protective tube or immersion nozzle during handling and installation (especially important when performing operations in confined spaces)

  • strictly vertical installation of the protective tube on the collector of the sliding gate (affects the hydrodynamics of flows in the tundish)

  • reverse impact in case of opening of the protective tube “under the level” of the metal in the tundish

2. Increasing the productivity of the steel casting process

It is achieved due to the fast and accurate execution of technological operations, such as:

  • supply of powders to the tundish (about 600 kg in 5 min)

  • replacement of protective pipes of the steel-pouring ladle and submersible nozzles (~30-40 sec)

  • protective pipe inspection is carried out remotely by means of video surveillance

Rice.  2 Supply of powders to the tundish
Rice. 2 Supply of powders to the tundish

3. Improving product quality achieved through the following benefits:

  • fast supply of powders (TIS at start-up, after temperature measurement) – the duration of the entire operation is approximately 20 seconds

  • reproducibility of measurement points for temperature, hydrogen concentration and metal sampling (affects the quality of measurements) – the positioning accuracy of the robot is 0.06 mm

  • smooth installation and removal of the submersible nozzle

  • improved traceability of the casting process due to recording of process data

Rice.  3 Replacing the immersion nozzle
Rice. 3 Replacing the immersion nozzle

When performing pairing operations, the robot must determine the location of surfaces in space as accurately as possible. The changing temperature conditions of metallurgical production are a destabilizing factor. As the most practical method for determining the location of objects in space, the laser scanning method has proven itself. It allows you to accurately and quickly (3-4 seconds) take measurements, regardless of the distance to the objects. As a result, the robot receives a 3D model of the target area and can position itself accurately.

Rice.  4 Positioning with a laser scanner
Rice. 4 Positioning with a laser scanner

A typical industrial robot has 6 axes of movement with a coverage area of ​​2500–3000 mm. To expand the working area, the robot is installed on an additional 7th axis, which allows it to perform all the necessary manipulations and cover all working areas.

Rice.  5 Example of a rotary additional axle
Rice. 5 Example of a rotary additional axle

A robotization project is always more than just placing a robot on a platform. The nodes and mechanisms with which the robot interacts are also subject to changes. The storage infrastructure for consumables should provide for their safe loading and monitoring of residues.

Since all UNRS differ in design, the process of adapting robotic solutions is the main task during design and includes the following additional steps:

  1. Development of a digital twin of the new UNRS infrastructure project

  2. Autonomous training of a robot on a mockup

Rice.  6 Development of the digital twin
Rice. 6 Development of the digital twin
Rice.  7 Robot training on a mockup
Rice. 7 Robot training on a mockup

Conclusion

Robotization of production is not a task for the future generation, but these are tasks that must be solved now, so that the new generation of metallurgists can develop productively in those conditions that fully comply with modern technological requirements.

Without a doubt, in this race of technology, the winner will be the one who first enters into it and maintains the rhythm set by technological progress. All basic Industry 4.0 solutions already exist and are being developed with each new project, and the scientific community is already thinking about technologies for subsequent industrial revolutions. The technological gap between leaders and laggards is growing every year, and in order to stay in the group of leaders, enterprises need to continuously improve their production.

Similar Posts

Leave a Reply