Electric Melting Processes in the Glass Industry

The all-electric glass furnace using the cold-top process represents a particularly energy-efficient and low-emission melting process. By completely eliminating fossil fuels, heating is done exclusively electrically, directly in the glass bath.

A characteristic feature of the cold-top principle is the closed batch blanket on the melting surface. This reduces heat loss, minimizes dust emissions, and ensures stable process control.

The uniform energy input allows for precise temperature control and creates optimal conditions for high-quality glass – especially for special glasses.

Typical advantages include:

• High energy efficiency through direct electrical heating
• Low emissions and reduced exhaust gas management
• Stable melting conditions due to a closed batch blanket
• Very good glass quality with high process control

All-electric cold-top furnaces are individually designed based on melting capacity, glass type, and production requirements, offering a future-proof solution for modern glass production.

The hot-top glass furnace is a proven melting concept for high throughputs and flexible applications. In contrast to the cold-top principle, heating occurs above the glass bath and is typically based on the use of gas or oxy-fuel burners.

The open melting surface allows for direct energy transfer and supports rapid melting of the batch. This makes the hot-top process particularly suitable for applications with high melting capacities and varying raw material compositions.

Through targeted control of flame guidance, air supply, and exhaust gas flow, the melting process can be precisely adjusted and operated stably.

Typical advantages include:

• High melting capacities with flexible process control
• Direct energy input via gas or oxy-fuel burners
• Good adaptability to different batches and glass types
• Proven technology for continuous production processes

Hot-top glass furnaces are individually designed based on furnace geometry, heating concept, and production requirements, offering a robust solution for high-performance melting processes.

Operating a hot-top glass furnace requires the coordinated interaction of various plant components. Heating is provided by gas or oxy-fuel burners in the upper furnace chamber and by electrodes in the melt.

Burner systems with corresponding gas and oxygen supplies are used, as well as electrical components such as electrodes, transformers, thyristors, and control cabinets. Suitable cooling water and air cooling ensure safe and stable plant operation.

For charging, feeder systems such as piston or screw chargers are used, which are individually adapted to the furnace type and process. In addition, systems such as furnace pressure measurement and drainage contribute to process stability and operational safety.

After melting, further processing takes place via coordinated forehearth systems, which enable controlled temperature management up to the forming stage.

Cold-top glass furnaces operate with a fully electric energy input, where the melt is heated directly by electrodes in the glass bath. This results in specific requirements for the plant technology used.

Central components are electrical systems such as electrodes, transformers, power electronics (thyristors), and control cabinets, which enable precise control of the energy input. Reliable cooling water treatment and distribution are also required for safe operation.

In addition, air cooling systems are used to specifically limit thermal loads. The batch is fed via adapted charger systems, for example, X/Y chargers, which ensure uniform and controlled charging.

Systems such as furnace pressure measurement and drainage concepts are integrated to monitor and secure the process. After the melting process, forehearths take over the targeted temperature control and conditioning of the melt for further processing.