Electric Boosting Power Share Rises Steadily, Molybdenum Electrode Configuration Upgrades Across the Board

From auxiliary boosting to deep electric melting, electrification of glass furnaces is undergoing a quantitative change. In the early days of electric boosting, the electric heat share was often only a few percent and electrodes served only as supplementary heating; in recent years the power configuration of new furnace types has generally increased, with the electric heat share exceeding a quarter on some high-output lines, and electric boosting has upgraded from an adjustment tool to an important source of melting heat. Furnace types that once treated electric boosting as a supplement are also reserving higher power interfaces. With power up, the current passing through molybdenum electrodes increases, and the design logic of the whole electrode system is changing. The root of the rising share is users' combined pursuit of quality, energy consumption and output, not a simple equipment race.

Three changes brought by higher power

• Larger electrodes: to keep current density per electrode within a reasonable range, molybdenum electrode diameter and length increase together;
• More groups: melting zones are divided more finely, with more side-entry electrode groups and more openings;
• Stronger power supply: dedicated rectifiers and transformers are upgraded, tap combinations become more complex and protection requirements higher;
• Water-cooling protection: cooling and sealing structures for electrodes are upgraded in parallel, supporting long-term operation.

Life test at high current density

The higher the current density, the faster the anodic melt erosion and thermal stress damage of the electrode. Long-term operation at high current density requires higher density and purity in the electrode, otherwise the corrosion rate rises markedly and replacement intervals shorten. Uniformity of electrode material and machining quality also affects current distribution, and any weak point can be amplified under heavy load. Dense electrodes made by powder metallurgy high-temperature sintering show a clear life advantage under high-power conditions: the purchase price is higher, but the total cost amortized per tonne of glass is actually lower, and more and more users have worked out this equation.

Supporting design becomes critical

For electrode products and specifications in the glass melting step, see our glass electric melting furnace electrode specifications; for process notes on power supply, arrangement and operation control, see our technical process guide.

High-power electric boosting is not simply adding electrodes. Electrode arrangement must be combined with liquid flow simulation to avoid local overheating that washes away refractories; power supply parameters must match the resistance characteristics of the melt to prevent short circuits and arcing; electrode replacement must be coordinated with the operating conditions of the flame system to avoid furnace temperature swings. During commissioning, a staged power ramp-up plan is also needed to keep new electrodes from carrying excessive current too early. This work pushes electrode suppliers to the front end of furnace design. The WeiBeam.com technical team's analysis is that the trend of rising electric boosting power will continue long term, and the electrode industry will benefit from both volume and specification upgrades; the model of supplying goods without process coordination is gradually being eliminated, and only an integrated capability of design, product and service can capture the dividends of this upgrade cycle.