Frequently Asked Questions About Induction Furnaces

Work backwards from output, not from furnace size. Tell us the tons of good metal you need per shift, the alloy, and how many hours a day you run. We size the furnace so one heat matches your pouring cycle and the installed power delivers that heat inside it. As a rough guide, a 1-ton furnace with 700 kW melts about one ton of steel per hour; below that ratio the furnace holds more than it can heat and your cost per ton rises.

A steel shell furnace has a welded steel frame with laminated magnetic yokes around the coil; an aluminium shell furnace has a lighter cast aluminium frame and no yokes. Steel shell gives lower stray field, better rigidity and longer coil life, and is what we recommend above 3 tons or for continuous three-shift melting. Aluminium shell costs less, ships lighter and relines faster, and is the sensible choice for job foundries below 3 tons on one or two shifts.

For large melting furnaces on a weak or remote grid, KGPS. It tolerates voltage dips and distorted supplies, and any competent local electrician can replace a thyristor sourced worldwide. For heating lines, hardening machines, small furnaces, or sites where the utility charges for reactive power, IGBT — its power factor stays high across the load range and control resolution is much finer. We will recommend one over the other for your specific duty rather than quoting whichever we would prefer to sell.

Yes, and for most foundries it is the right configuration. A switching cabinet with mechanical and electrical interlocks directs full output to either body, one at a time. You melt on one while the other is relined or cooling, so a lining change stops being lost production. Changeover takes under two minutes.

Six answers: the alloy you melt or the part you heat, target output per hour, working hours per day, your grid voltage and frequency, available floor area and ceiling height, and the destination port. With those we return a capacity and power recommendation, a plant layout, a heat balance and a line-by-line quotation, normally within three working days.

Yes — it is built to your grid, not adapted on arrival. Specify 380 V/50 Hz, 400 V/50 Hz, 415 V/50 Hz, 440 V/60 Hz or 480 V/60 Hz at order, and we build the rectifier and control system to match. Medium-voltage units above roughly 3,000 kW are supplied with the matching rectifier transformer. Tell us the grid details in your first enquiry so the quotation is correct from the start.

We issue a transformer and cable schedule with the quotation, sized to the furnace rating with the correct margin, including recommended cable cross-sections, protection settings and the earthing arrangement. For a 1,000 kW furnace, plan on roughly a 1,250 kVA transformer. Your local electrical contractor works to our schedule; we do not supply the incoming substation itself.

A foundation drawing with loads, bolt positions and pit dimensions is issued after order so your civil work runs in parallel with manufacturing. You also need a cooling water position, a cable route from the transformer, adequate ceiling height for charging, and a drainage plan for the melting pit. All of it is on the layout drawing.

Yes. Our engineers travel to your site to supervise installation, install and sinter the first furnace lining, commission the system on your own charge material, and train your operators and maintenance staff. Duration is typically 10–20 days depending on the plant. Travel, visa, accommodation and daily allowance arrangements are set out in the quotation so there is no surprise afterwards.

For a single melting furnace, typically 2–3 weeks from container unloading to first heat, provided the foundation, transformer and water supply are ready when the containers arrive. Larger multi-furnace plants take 4–8 weeks. The critical path is almost always site preparation, not the equipment — which is why the foundation and electrical drawings are issued immediately after order.

It depends on the alloy, tapping temperature, holding practice and how carefully the first sinter was done — the range across real installations is wide. Silica linings on grey iron generally run considerably longer than alumina linings on high-temperature alloy steel. What is controllable is the practice: correct chemistry for your alloy, correct ramming density, and the sintering curve followed properly. Our engineer installs and sinters the first lining and supervises your team on the second.

For a modern medium frequency furnace melting clean cold scrap to a 1,600 °C tap, budget somewhere in the region of 550–620 kWh per ton, with larger furnaces at the lower end. Real consumption depends heavily on charge density, how long metal is held after melt-down, and lining condition. Holding a full furnace for an hour waiting on a mould can add more consumption than any efficiency difference between suppliers.

Daily: check cooling water flow and temperature, inspect the lining, check the water-cooled cable for chafing. Weekly: check water conductivity, clean the cabinet filters, check hydraulic fluid level. Monthly: check capacitor capacitance, inspect busbar connections for heating, test the earth-leakage and water-flow interlocks. The full schedule is in the English manual and is covered in commissioning training.

We quote a recommended two-year spares kit with every furnace so the parts budget is known before the equipment arrives. The core items are thyristor or IGBT modules, fast-acting fuses, a spare water-cooled cable, resonant capacitors, control boards, hydraulic seals and enough refractory for two linings. Every part is cross-referenced to your machine serial number, so a reorder is a part number rather than a description and a photograph.

As standard: water flow and water temperature interlocks, coil earth-leakage detection, a water-leak alarm on the furnace body, over-current and over-voltage protection, phase-loss detection, emergency stop circuits, a mechanical tilting lock that holds the furnace without hydraulic pressure, and an emergency hand pump to return the furnace upright without electrical power. Operator safety practice is part of commissioning training, not an afterthought.

Standard terms are 30% deposit with the order and 70% against a copy of the bill of lading, by T/T. We also accept an irrevocable L/C at sight from a first-class bank. For large multi-furnace projects, staged payments against manufacturing milestones can be arranged. Terms are fixed in the contract before manufacturing starts.

30–45 days for a small aluminium-shell furnace or a standard power supply; 45–75 days for a steel-shell melting station; 50–80 days for a dual-track two-body plant; 60–120 days for vacuum furnaces and custom heating lines. The clock starts from receipt of deposit and confirmation of the final technical specification, not from the enquiry.

Yes, and we encourage it. Every system is assembled and run on load in our works before it is dismantled for shipment. You are welcome to attend the factory acceptance test in person or appoint a third-party inspection company such as SGS or BV. If neither is practical, we supply a video record and the written FAT report.

Seaworthy export packing: fumigated timber crating compliant with ISPM 15, moisture barriers and desiccant on the electrical cabinets, and steel bracing on the furnace body. We prepare the container loading plan, handle export declaration and supply the full document set — commercial invoice, packing list, bill of lading, certificate of origin and insurance certificate. We ship FOB, CFR, CIF or DDP as you prefer.

12 months from commissioning, or 15 months from bill of lading date, whichever comes first, covering manufacturing and material defects on the equipment we supply. Consumables — refractory lining, crucibles, water-cooled cable — are excluded, as is damage from operating outside the specified conditions. Beyond the warranty period we supply spare parts for the life of the machine.

By email and WhatsApp with an English-speaking engineer during working hours, plus remote diagnostics over an Ethernet link where the site allows it — which resolves most control and parameter issues without a visit. Where a site visit is needed we despatch an engineer; where a part is needed we air-freight it. Spare parts are cross-referenced to your machine serial number so identification is not part of the delay.