This guide will walk you through how to scientifically calculate and select the most suitable induction furnace capacity based on your foundry’s actual production needs.
Core Calculation Formula: The Reverse Derivation Method
The most scientific way to select furnace capacity is to start with your target annual output and work backward to determine the required hourly melt rate, which ultimately defines the ideal single-furnace capacity.
1. Define Target Annual Output (A):
Identify the total weight of finished castings your foundry plans to produce over the coming year (unit: tons/year). Misalnya, 3,000 tons/year.
2. Estimate Actual Annual Melting Requirement (B):
Rumus: B = A ÷ (Casting Yield Rate × (1 - Burn-off Rate))
Catatan: Umumnya, the casting yield rate ranges from 50% ke 75%, and the burn-off rate ranges from 2% ke 5%. Untuk menyederhanakan, you can divide the annual output by a comprehensive yield rate (MISALNYA., 60%).
Contoh: 3,000 ÷ 0.6 = 5,000 tons/year
3. Calculate Annual Working Hours (C):
Rumus: C = Working Days per Year × Shifts per Day × Hours per Shift
Contoh: Berdasarkan 300 working days/year, 2 shifts/day, Dan 8 hours/shift: 300 × 2 × 8 = 4,800 hours/year
4. Calculate Required Melt Rate per Hour (D):
Rumus: D = B ÷ C
Contoh: 5,000 ÷ 4,800 ≈ 1.04 tons/hour
5. Determine Single-Furnace Capacity (E):
Rumus: E = D ÷ Heats per Hour
Contoh: Assuming a 50-minute melt cycle per heat (kira-kira. 1.2 heats/hour): 1.04 ÷ 1.2 ≈ 0.87 tons.
Kesimpulan: To allow a safe buffer, A 1-ton medium frequency induction furnace is highly recommended.
Critical Factors Influencing Capacity Selection
Beyond theoretical calculations, you must consider the following four practical variables before making a final decision:
| Factor | Keterangan | Capacity Adjustment Advice |
| Maximum Single Casting Weight | If you occasionally need to pour extra-large castings, a single tap of molten iron must meet the entire pouring requirement at once. | The furnace capacity must be greater than the maximum weight of a single casting (including the gating and riser system). |
| Grid Power Constraints | Transformer capacity is a hard limitation. Larger furnaces require higher power ratings. Contohnya, a 1-ton furnace typically requires an 800–1000 kVA transformer. | If local grid power is limited, you may need to opt for multiple smaller-capacity furnaces running in parallel, or upgrade your transformer. |
| Produk & Material Diversity | If your foundry produces a wide variety of materials (MISALNYA., switching between gray iron, Besi ulet, and various alloy steels) and requires frequent grade changes. | It is recommended to choose multiple smaller-capacity furnaces (MISALNYA., two 0.5-ton furnaces instead of one 1-ton furnace) to facilitate easy furnace washing and prevent material contamination. |
| Pouring Line Synchronization | The furnace’s tapping speed must match the speed of the molding and pouring lines. Tapping too quickly leads to temperature drops while waiting; tapping too slowly bottleneck the production line. | For continuous automated molding lines, A “one-to-two” (dual-sharing) configuration (one power supply feeding two furnace bodies—one melting while the other holds) is recommended to ensure continuous liquid metal supply. |
Key Selection Trends for 2026
When designing solutions for clients, the following industry trends are highly worth highlighting:
High Power Density & Pencairan Cepat: Modern foundries increasingly favor high-power-density furnaces. Matching a larger power supply with the same capacity shortens melt times (MISALNYA., reducing a 1-ton furnace’s melt cycle from 60 ke 40 menit). This not only boosts efficiency but also minimizes heat loss and oxidation burn-off, lowering energy consumption per ton.
Widespread Adoption of Dual-Sharing Systems: Compared to single-furnace setups, dual-sharing power systems (where a single power supply dynamically allocates power between two furnace bodies) are becoming the industry standard. They eliminate idle waiting times between melting and pouring, maximizing overall equipment utilization.
