Professional ‘Channel Cutter’ with Baier railing systemPublished 28/9, 2021 at 10:37
The railing system from Baier is a fully automatic surface milling system for demanding tasks such as the dismantling of nuclear power plants with contaminated concrete or for precise floor markings at airports and train stations. As part of the dismantling, the contaminated layers in the floor and wall area must be removed before the actual dis-mantling can begin. At the moment, the removal of coatings in the contaminated area is carried out by hand with abrasives with approximately 50,000 m² needing to be re-moved per reactor.
Baier states that the decisive factor for efficient milling of the surfaces is the constant milling depth in order to remove the coating (thickness approx. 3mm) with one milling process if possible, or not to mill too deeply and thus not unnecessarily increase the amount of material to be disposed of, which would otherwise make disposal significantly more expensive. Baier’s milling system is generally suitable for operations in which milling is carried out up to 50mm wide and 45mm deep and in one cut in reinforced concrete and all other types of stone. Surfaces to be milled often have unevenness (large spherical areas or depressions) that are reflected in the milling. This unevenness inevitably leads to a constant milling depth that cannot be guaranteed neither by freehand nor by a manually guided milling machine. This inevitably leads to rework or to higher amounts of waste.
Unevenness on the surfaces
The Baier system is suitable to minimise the working time of the employees in the contaminated area and to optimise removal. The unmanned use of the milling system enables longer working hours overall whilst the presence of personnel in dangerous areas is minimised. The surface milling system consists of a modular rail system with precise guidance for unmanned milling on ceilings, walls and floors. The precise guidance and the fast unmanned feed ensure a perfect line with minimal wear on the diamond discs. Wear is recorded using a diagnostic tool with the tool change therefore taking place as required, in contrast to the previously practiced fixed change cycles. By reading out the work data, the worked area and the period of work can be recorded and can therefore also be reconstructed.
Unmanned removal of the contaminated material is said by Baier to increase efficiency whilst any abrasion is minimised, thereby reducing the amount of contaminated dust. Current machine tools are in part able to monitor some operating parameters, however, basic monitoring, recording and evaluation of all relevant operating parameters is not ‘state of the art’, especially in the case of hand held machines.
The assessment of the machine wear and the expected remaining service life of the machine components are currently carried out using simple tables or ‘empirical values’. By using suitable sensors and cyclical recording of the operating parameters, after a sufficient data-base has been created, a classification and evaluation of this data using an AI would be conceivable. This should go hand in hand with a maximisation of the service life with a corresponding reduction in running costs and resource savings.
Sustainability (economical - ecological - social)
Significant reduction in the amount of disposal is achieved, as only the defined layer of the contaminated area is milled off. According to calculations by the engineers in the NPP, a 50% reduction in the amount of waste is expected. If only 1 mm too much is milled off on an area of 50,000 m², there would only be an additional expense of €2.5M in relation to disposal costs. In addition, no concrete must be removed together with the epoxy coating, as these then have to be separated again, which in turn increases the costs. A significant improvement of health and safety at work is experienced, as the milling machine is no longer being operated by hand and thus the stress on employees is greatly reduced. Furthermore, significantly higher efficiency can be expected, thus resulting in productivity being signifi-cantly increased and the time required is reduced. The machine can process 5m2/h, which Baier says is roughly 40 times more than by a human operative.