Glasugnar

Glasugnar are industrial furnaces used to melt glass for the production of glass products. They operate at high temperatures, typically around 1400 to 1500 degrees Celsius, and are lined with refractory brick or other heat-resistant materials to withstand chemical wear and thermal stress. In a glass plant the furnace feeds a forming section, and the melt produced by the glasugn is either used in a batch process or in a continuous process.

There are several principal types of glasugnar. Container glass furnaces melt glass for bottles and jars and often use a regenerative or recuperative system to recover heat from exhaust gases. Flat glass furnaces are part of the line that produces sheet glass, commonly via the float glass process, which requires a dedicated melting tank and a downstream coating and forming sequence. Older or specialized operations may still use pot furnaces or other batch-melting arrangements. Modern plants frequently employ continuous tank furnaces with regenerators or recuperators and advanced controls to regulate melting, refining, and homogenization of the melt.

Materials and process: the basic batch consists of silica sand or crushed glass (cullet) with additives such as soda ash and limestone. The batch is melted in the glasugn, refined to remove bubbles and impurities, and then delivered to the forming line through forehearths or feeders. Energy efficiency and emissions control are important considerations, with many plants using natural gas, fuel oil, or electricity and implementing heat-recovery systems.

Historically, glasugnar evolved from early pot furnaces in ancient glassmaking to modern continuous and float-glass technologies, reflecting advances in materials, design, and process controls. See also glassmaking and float glass.