Glass Manufacturing & Regenerative Tank Thermodynamics, Batch Fusion Loss & Cullet Rule
Glass Furnace Carbonate Fusion Loss, Cullet & Fuel Formula
Calculate Fused Virgin-Batch Glass Tonnage (t/d), Total Regenerative Furnace Pull (t/d), Cullet Share in Molten Pull (%), and Cullet-Reduced Specific Melting Energy (GJ/t).
Every tonne of virgin soda-ash + limestone glass batch vents 162 kg of CO2 up the stack—whereas recycled cullet melts at 100% yield and cuts furnace fuel 2.5% per 10% cullet!
Feeding `M_{batch}` (`t/d`) of virgin **Soda-Lime-Silica Raw Mineral Batch** (`~60%` quartz sand `SiO_2` + `~19%` soda ash `Na_2CO_3` + `~18%` limestone/dolomite `CaCO_3·MgCO_3` + saltcake fining agent) into a `1,580°C` cross-fired regenerative tank yields ONLY **`M_{fused} = M_{batch} * (1 - L_{ign} / 100)`** (`t/d` of molten glass, where **Carbonate Calcination / Fusion Loss `L_{ign} ~= 15%–17%`** escapes as process `CO_2` gas)! By contrast, crushed **Recycled Glass Cullet `M_{cullet}`** (`t/d`) already underwent endothermic silicate reaction—contributing `100%` of its mass to **Total Tin-Bath / Forehearth Pull `P_{tot} = M_{fused} + M_{cullet}`** (`t/d`) at **Finished-Glass Cullet Ratio `C_{pull} = (M_{cullet} / P_{tot}) * 100%`**, and trimming Zero-Cullet Specific Melting Fuel `E_0` (`GJ/t`) via the industry **2.5%-per-10%-Cullet Rule `E_{spec} = E_0 * (1 - 0.0025 * C_{pull})`** (`GJ/t`)!
Verify on a `532` t/d Architectural Float-Glass Tank—Virgin_Mineral_Batch `M_{batch}` = 420 t/d (B2), Carbonate_Fusion_Loss `L_{ign}` = 16.2% (B3), Recycled_Cullet_Feed `M_{cullet}` = 180 t/d (B4), and Zero-Cullet_Baseline_Fuel `E_0` = 6.40 GJ/t (B5): Fused Batch Glass equals `351.96` t/d (`68.04` t/d calcination `CO_2` vented! E2), Total Molten Glass Pull equals `531.96` t/d (E3), Cullet Fraction in Melted Glass equals `33.84%` (E4, higher than the raw `30.0%` belt-weight ratio!), and Specific Tank Fuel drops to **`5.859` GJ/t** (E5)!
| Glass Tank Mass & Energy KPI (L_ign=16.2%, Zero-Cullet Fuel E0=6.40 GJ/t) | Formula | Verified Output |
|---|---|---|
| Fused Virgin-Batch Glass (t/d) | Raw_Batch_t_d * (1 - Fusion_Loss_Pct / 100) | 351.96 t/d (150.84 t/d high-cullet campaign) |
| Total Molten Furnace Pull (t/d) | Fused_Batch_Glass_t_d + Cullet_Feed_t_d | 531.96 t/d (530.84 t/d constant pull) |
| Cullet Share in Molten Pull (%) | (Cullet_Feed_t_d / Total_Pull_t_d) * 100 | 33.84% (71.58% container/eco-float) |
| Specific Melting Fuel (GJ/t) | Zero_Cullet_GJ_t * (1 - 0.0025 * Cullet_Pct) | 5.859 GJ/t (5.255 GJ/t = -17.9% fuel!) |
Soda-Lime-Silica Carbonate Fusion Balance & 0.25%/Pct Cullet Energy Formula
Validate `Raw_Batch >= 0` t/d, `Fusion_Loss` in `[8, 25]`%, `Cullet_Feed >= 0` t/d (`with Raw_Batch + Cullet_Feed >= 10` t/d), and `Baseline_Fuel E_0` in `[3.5, 12.0]` GJ/t!
=LET(rb_t, B2, ls_p, B3, cl_t, B4, zf_g, B5, fb_t, rb_t * (1 - ls_p / 100), pl_t, fb_t + cl_t, cs_p, (cl_t / pl_t) * 100, IF(OR(rb_t < 0, ls_p < 8, ls_p > 25, cl_t < 0, rb_t + cl_t < 10, zf_g < 3.5, zf_g > 12), "Invalid Glass Input", ROUND(zf_g * (1 - 0.0025 * cs_p), 3)))High-Cullet Decarbonization Campaign (`180` t/d Batch + `380` t/d Cullet) Check
Install optical color-sorting to boost cullet to `B4 = 380` t/d while cutting virgin mineral batch to `B2 = 180` t/d at the same `530.84` t/d pull (E3): Cullet Share in Molten Pull E4 climbs to **`71.58%`**, slashing Specific Natural-Gas/Oxy-Fuel Demand E5 to **`5.255` GJ/t** while eliminating `38.9` t/d of raw carbonate process `CO_2`!
=IF(ISTEXT(E5), E5, LET(pl_t, B2 * (1 - B3 / 100) + B4, ROUND((B4 / pl_t) * 100, 2)))Try the example
Use the original values or change them to test your understanding.