A green sand foundry has six main departments: melting, sand preparation, core making, moulding, pouring and cleaning. Add dust filtration, cooling water, compressed air and a laboratory. Before choosing machines, fix one number: how many tonnes of good castings per hour you will produce. Every other capacity follows from it.
Start with capacity
Work backwards. If you want 2 t/h of good castings and your gating/feeder ratio is 40%, you need to pour about 3.3 t/h of liquid metal. Add scrap and losses, and melting capacity rises to around 3.5 t/h.
For sand, look at the sand-to-metal ratio. On flaskless lines it is usually between 5:1 and 8:1. Pouring 3.3 t/h means preparing 20–30 t/h of sand.
1. Melting
- Induction furnace (power supply + crucible) or cupola
- Furnace transformer and MV switchgear
- Closed-circuit cooling
- Charge car or magnet crane
- Pouring ladles and ladle heater
For cast iron, plan roughly 550–650 kW per 1 t/h of melt. Details in our induction melting furnace guide.
2. Sand preparation
- Sand mixer (rotor or pan type)
- Sand cooler (fluid bed or drum)
- Screen, magnetic separator, bucket elevator and belt conveyors
- Sand silos and bentonite / coal dust additive silos
- Moisture and temperature control, automation panel
The sand plant takes the most space and is where most mistakes happen. Above 45 °C sand temperature, mould quality drops, so do not undersize the cooler.
3. Core making
- Cold box or shell core machines
- Core sand mixer
- Amine gas scrubber (for cold box)
- Core drying and coating
4. Moulding
- Vertical flaskless line (DISAMATIC type): series production, small to mid-size parts
- Horizontal flaskless line: larger parts, easier core setting
- Automatic flask line: large and heavy parts
- Pattern change car, core setter
- Mould conveying and cooling conveyor
Choose the line by part size, volume and core density. Moulds per hour times metal per mould gives your hourly pouring demand.
5. Pouring
- Automatic pouring unit (bottom pour, tilting or pressurised)
- Ladle transfer system
- Inoculation unit
Above about 150 moulds per hour, automatic pouring is practically essential.
6. Shakeout and cleaning
- Vibrating shakeout grid or drum
- Sprue breaker
- Hanger, tumble or pass-through shot blasting machine
- Grinding and fettling
Auxiliary systems (most often forgotten in budgets)
- Dust collectors: separate ones for melting, sand plant, shakeout and blasting
- Compressed air: compressor, dryer, piping
- Cooling water: tower, pumps, heat exchanger
- Electrical: main transformer, distribution panels
- Laboratory: spectrometer, sand testing equipment
- Cranes and forklifts
These items can make up 20–30% of the total investment. Tick which ones each offer includes.
New or used
Melting furnaces, shot blasting machines and sand mixers give the biggest savings when bought used; chosen well, they run for years at about half the price of new. For moulding lines and automation, check age, spare parts and control system carefully.
ZENES brings used lines and machines from Europe and compares new machine offers from Chinese, European and Turkish makers on the same scope. We handle layout, machine selection, dismantling, transport, installation and commissioning as one contractor.
FAQ
What is the minimum equipment for a small foundry?
Induction furnace, sand mixer, moulding machine (jolt-squeeze or manual), shakeout and shot blasting machine, plus filtration and cooling.
How much power does 1 t/h of castings need?
About 600–700 kW for melting. The whole plant usually needs 1.5–2 times that in transformer capacity.
How long does it take to set up a foundry?
It depends on machine delivery. With used machines 4–6 months; with a new automatic line 8–14 months is typical.
