The process of glass production is complex – and an aggravating factor in this industry is a growing shortage of skilled workers. This makes it all the more important to ensure that operation of the production plant is as simple and maintenance-friendly as possible.
With its new dross box, which was presented for the first time at glasstec 2022, Grenzebach, found a solution to this issue and at the same time set a milestone: the new design offers outstanding user-friendliness and safety, both in operation and maintenance.
Franz Krommer, Product Manager Glass at Grenzebach, explains the background to the redesign: “Glass plants have to run continuously, especially in the hot end. Downtimes must therefore be kept as low as possible. Grenzebach has therefore made significant changes in the area of roller technology and the housing. As a result, plant operators can now maintain and operate the dross box even more easily. This saves a lot of time in day-to-day production, increases process reliability, and in turn boosts efficiency and productivity.”
Simpler height adjustment
Simplified and fast height adjustment of the lift-out rollers enables individual adaptation of the curve geometry to the needs of production. In addition to greater process reliability, this ensures more flexibility, especially when producing different glass thicknesses. With the new dross box, this height adjustment is fast and at the same time safe without time-consuming loosening of the bearing caps.
Special seals make this possible. The height adjustment is carried out with individual direct drives.
This is an innovation that Mr Krommer says customers are particularly excited about: “We’ve already received a lot of positive feedback for our optimisations,” he notes.
As an additional option, Grenzebach offers an automated version in which all settings for the corresponding glass thickness can be saved and retrieved at any time.
Flexible roller mount
Another advantage is that the dross box can be fitted with different types of lift-out rollers: steel, coated steel and ceramic are all equally possible. This gives customers greater flexibility in their choice of rollers.
Improved maintenance
Changing the graphite bars is now also much less work. The rolls are permanently cleaned via multi-part graphite bars with pneumatically adjustable contact pressure to ensure a clean process.
Thin and special glass
The standard version of the dross box is designed for a maximum temperature of 650°C; the premium version covers application ranges of up to 850°C – a feature that is important in the production of thin glass or special glass. This high-temperature version is so far unique on the market. “Particularly among thin glass manufacturers, we have seen high demand for our dross box in recent months,” says Mr Krommer.
Optimum atmosphere separation
An important task of the dross box is to separate the protective atmosphere in the tin bath from the atmosphere of the cooling channel. This is done by means of graphite strips below the rollers and by curtains above the glass, as well as through the application of nitrogen curtain sealings. The new dross box has four height-adjustable curtains with special suspension, made of a particularly heat-resistant material – to ensure that they do not deform and remain gas-tight even at high temperatures.
Interested parties can be shown the functions of the new dross box in person at Grenzebach’s showroom ‘365 Days of Grenzebach World’ which is open all year-round at the company’s site in Hamlar, Germany or via an online appointment.
Image: With customisable roller technology, special roller sealing and safe maintenance options, the new dross box achieves valuable process improvements.