Drache Umwelttechnik: Cerapor foam filters, refractory parts and melt treatment systems

Cerapor Ceralu and Cerazirk foam ceramic filters, DFS refractory parts, DBN coating, filter boxes, degassers and launders from Drache Umwelttechnik. Selection and a quotation for your project.

Cerapor Ceralu foam ceramic filters for DC lines

Cerapor Ceralu Al2O3 filters have cleaned aluminium on continuous DC lines for more than three decades. They resist all aluminium alloys, including high-magnesium and aerospace grades. The HF variant handles very high metal flow, and the duplex filter combines two porosities in one plate.

Sizes from 9 to 28 inches
Porosity from PPI 25 to PPI 60
HF filter: PPI 40, 50, 60
Expanding or fibre gasket

Ceralu and Cerazirk filters for foundry moulds

Cerapor Ceralu moulding filters serve aluminium foundries, with versions for low-pressure processes. Cerazirk ZrO2 filters serve steel, nickel and cobalt base alloys and large iron parts poured in moulds. They withstand temperatures up to 1700 °C.

Ceralu: 40×40×22 to 100×100×22 mm
Cerazirk: porosity up to PPI 30
Cerazirk: up to 1700 °C
Cerazirk suits magnesium melts

DFS filter box inserts and launder segments

Drache Fused Silica is used for filter box inserts such as inlet channels, stepped bricks and outlet channels. Launder segments range from small sections to large segments for billets, rolling ingots and transfer launders. The material resists wetting by aluminium and thermal shock.

In-house DFS material
Inlet and outlet channels
Launder segments for billets and ingots
Custom shapes to drawing

DFS Fine spouts, stoppers and hot-top rings

For rolling ingots and extrusion billets Drache supplies spouts, stoppers, hot-top rings and spout seats in many sizes and shapes. The parts are made of fine-grained Fused Silica Fine. On request they are coated with DBN boron nitride.

Fused Silica Fine material
Spouts and spout seats
Stoppers and hot-top rings
Optional DBN coating

DBN coating, DKS calcium silicate and repair mastic

DBN boron nitride coating comes in three types with 25, 15 and 10% BN. Carbon fibre reinforced DKS 200 calcium silicate parts serve as transition plates on Wagstaff billet tables. Ceramold Clean mastic repairs cracks and joints in refractory parts.

DBN: up to 1000 °C in air
DBN: 6 kg buckets
DKS: 850 °C service temperature
Ceramold Clean: 5 and 25 kg

Silicon nitride tubes, aluminium titanate and crucible furnaces

Si3N4 silicon nitride is used for riser tubes in low-pressure die processes, heater tubes and thermocouple protection tubes. Aluminium titanate (ATi) serves riser tubes and sprue bushes. Immersion-heated crucible furnaces hold the melt within ±2 °C.

Polished Si3N4 riser tubes
ATi sprue bushes
Furnaces from 100 kg to about 2 t
Furnace liner life up to 1.5 years

Filter boxes and filter preheating systems

Drache filter boxes come in single and double configurations, with body, lid, preheater and base independent of each other. The filter is preheated by the electric Flow Heater, a gas burner or a resistance-heated lid. The Flow Heater heats air to 1100 °C without combustion gases.

Flow Heater: 40 and 60 kW
Gas preheating: 30–70 kW
Resistance lid: 15–25 kW
Three drainage options

Degassers, Filter-Combibox and launder systems

Drache degassers remove hydrogen from aluminium with argon, with optional chlorine via MBS purging systems. Units have one to four rotor chambers in fixed or tilting design. The Filter-Combibox combines degassing, temperature control and filtration in one box.

Degasser: 1 to 4 rotor chambers
Combibox: 11–12 kW immersion heaters
Six standard launder sections
Launder dams 50, 75 and 100 mm

How to choose a Drache product

Selection starts with the foundry area. For continuous DC aluminium lines Drache offers Cerapor Ceralu filters, filter box inserts, launders, spouts and stoppers; for mould foundries, Ceralu moulding filters, silicon nitride tubes and crucible furnaces; for steel and iron, Cerazirk filters.

Next come the filter size and porosity or the part material: Drache Fused Silica for filter boxes and launders, Fused Silica Fine for spouts and stoppers, SiC-based material for parts with very high abrasion, and Al2O3-based material for long contact with liquid aluminium.

Aluminium filtration on DC lines

Cerapor Ceralu Al2O3 filters come in sizes from 9 to 28 inches; the flow table of the manufacturer covers porosities from PPI 25 to PPI 60. Besides size and porosity, buyers weigh metal flow, tonnage per filter, melt cleanliness ahead of the filter and preheating.

Filter boxes come in single and double configurations. The filter is preheated by a 40 or 60 kW Flow Heater with air up to 1100 °C, a 30–70 kW gas system within 15–25 minutes, or a 15–25 kW resistance-heated lid.

Refractory parts and coatings

Drache Fused Silica is used for filter box inserts such as inlet channels, stepped bricks and outlet channels, and for launder segments up to transfer launders. Spouts, stoppers, hot-top rings and spout seats are made of Fused Silica Fine, with optional DBN coating.

Large parts include deep-bed filter liners, degassing inserts and transport crucibles.

DBN coating holds 25, 15 or 10% boron nitride and works up to 1000 °C in air. Carbon fibre reinforced DKS 200 calcium silicate parts serve as transition plates on Wagstaff billet tables, with a service temperature of 850 °C.

Mould foundries, steel and iron

Ceralu moulding filters come in 40×40×22, 50×50×22, 75×75×22, 75×50×22 and 100×100×22 mm, and there are filters for low-pressure processes. Riser tubes, heater tubes and thermocouple sheaths are made of silicon nitride, sprue bushes of aluminium titanate.

Cerazirk ZrO2 filters for steel, nickel and cobalt base alloys and large iron parts withstand up to 1700 °C, with porosity up to PPI 30. Immersion-heated crucible furnaces hold from 100 kg to about 2 t, with liner life of up to 1.5 years and more.

Degassers, Filter-Combibox and launders

Drache degassers remove hydrogen with argon, optionally adding chlorine via MBS purging systems; units have one to four rotor chambers in fixed or tilting design. Supply includes the gas control system and the electrical cabinet.

The Filter-Combibox combines degassing, temperature control and filtration: two chambers, a vertical U-type foam filter that can be changed during the pour, and 11–12 kW immersion heaters. Launders come in six standard sections, and launder dams are 100, 75 or 50 mm thick.

The manufacturer supports projects through installation, commissioning and operator training.

The manufacturer

Drache Umwelttechnik GmbH was founded in 1984 as Drache Keramikfilter Produktions-GmbH and is based in Diez, Germany. The duplex filter with two porosities followed in 1989, and DBN coating and DKS parts in 2012.

Subsidiaries operate in the USA and the UAE. In 2026 Porvair plc is acquiring all shares of Drache and integrating it into its Metal Melt Quality division alongside SELEE Corporation.

Drache and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of Drache and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.