Which recuperative glass tanks does IWG Glasofenbau supply?

A recuperative end-fired glass tank is a gas-fired melting furnace with burners at one or both ends. The combustion air is preheated in a recuperator: hot exhaust gases transfer their heat to the incoming air. This reduces gas consumption, ensures stable flame ignition, and increases efficiency.

End-firing creates a clear heat axis from the burner to the refining zone. This supports refining, ensures high homogeneity, and uniform temperatures across the glass surface, breast walls, and crown. Crucial factors are precisely controlled flame length, burner pressure, and draft management. Slightly lean operation can reduce NOx emissions; with moderate excess air, reduction effects in the glass remain low.

Where limit values are strict, low-NOx burners, exhaust gas recirculation, or moderate O₂ enrichment are available as equipment options. Result: a robust, energy-efficient furnace solution for small to medium pull rates – with reliable product quality, compact design, and attractive investment.
With the recuperative end-fired glass melting tank from IWG, you can produce, for example, the following types of glass:

A recuperative side-fired glass tank is a gas-fired melting furnace with staggered burners arranged along the side walls. The combustion air is preheated in the recuperator by the hot exhaust gases – gas consumption noticeably decreases, flames ignite stably, and overall efficiency increases.

Applications: Quartz glass is the material of choice for high-power lasers, UV lithography in microchip manufacturing, and optical components in space research. In industrial metrology, it is used for windows and lenses that must withstand extreme temperatures or chemically aggressive environments without losing their optical integrity.

Side-firing ensures uniform transverse heating: heat is introduced across the width of the bath into the depth, which supports refining and homogeneity and creates stable temperature profiles across the glass surface, breast walls, and crown. Crucial factors are precisely controlled flame length, burner pressure, and draft management. Slightly lean operation can reduce NOx emissions; with moderate excess air, reduction effects in the glass remain low.

With the recuperative side-fired glass melting tank from IWG, you can produce, for example, the following types of glass:

Our recuperative furnaces can be equipped with precisely matched electrical boosting systems, depending on the product and pulling capacity. Melting boosting increases the available power directly in the melt, shortens start-up times, and creates reserves for high cullet ratios.

A thermal wall stabilizes the heat balance at the transition to the refining zone, smoothes temperature peaks, and supports bubble separation. The electrical throat heating acts precisely in depth, maintains the viscosity at the target level, and ensures reproducible temperature profiles up to the outlet.

Additionally, we use bubbling systems – tailored to your recipe – which can be operated with compressed air or oxygen. The precisely dosed gas promotes convection, accelerates refining, and reduces striae and inclusion defects without altering the glass chemistry.

We adjust the proportion of melting and refining through the design of walls and throats: Geometry, position, and flow are chosen such that heat is precisely introduced into the melt and the flow forms the desired circulation patterns. Optionally integrated air or furnace cooling allows for additional control reserves at critical points.