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Large Rotary Forging Furnaces Make U.S. Debut

June 13, 2008
An Israeli furnace manufacturer is introducing its large rotary forging furnaces to North America, including models with hearth diameters of 3, 4.5 and 6.5 meters.

Founded in 1936, Electrotherm Electrical & Metal Products Ltd. is a privately owned company based in Israel that develops, designs, and manufactures furnaces and ovens for industry. Today, the Electrotherm Group embraces three companies: Electrotherm Industry, Electrotherm Marketing (1978) Ltd., and Nanosol.

Electrotherm Industry specializes in forging and heat-treating furnaces for closed-die and ringrolling forging operations serving the aerospace, medical, and energy industries. The designs are well-suited for integration to production cells with automated manipulators.

This view shows an Electrotherm 4.5-meter rotary forging furnace about to be put into operation.

Electrotherm Industry (www.electrothermindustry.com) reports it has installed more than 450 rotary-hearth furnaces worldwide, and that these include a significant market share of the aerospace industry, and a notable representation in the orthopedic forging segment and the aluminum forging and heat-treatment industries. This customer base includes a majority of the principal engine blade manufacturers around the world, it claims.

Electrotherm Marketing offers technical support for finding industrial heating solutions. This subsidiary of Electrotherm Group manufactures heating elements, and represents leading firms from around the world in the fields of small furnaces, heating elements, heat tracing, heat exchangers, temperature controls, and sensors.

NanoSol , the group’s thi rd branch, is involved in the technology of producing sub-micron droplets from liquids, solutions, and suspensions for pharmaceutical, cosmetics, electronics and other industries.

Compact rotary furnaces
The compact ELRH models are specially designed for preheating of blades and vanes for aircraft engines and forged orthopedic implant s . In recent years, Electrotherm has landed several orders for its compact furnaces, a development that officials say reflects a growth trend in the orthopedic forging market segment.

Customized sizes are available.

These compact furnaces are available in four hearth diameters: 1, 1.2, 1.6, and 2 meters. They offer a maximum working temperature of 1,200°C (2,192°F), and are suitable for air or protective atmospheres.

The standard configuration includes:

  • Foot-pedal rotation control;
  • Continuous rotation feed to the press; and
  • An automatic option for integration in forging unit cells.

The furnaces are being used to forge various materials, including titanium and nickel alloys. Two North American customers for furnaces in these size ranges are FPD Co., McMurray, PA (www.fpdinc.com), and Doncasters Storms Forge, Springfield, MA (www.doncasters.com).

FPD uses mechanical and hydraulic presses to produce precision net-shaped and conventional titanium, stainless steel, and aluminum forgings, for the commercial and military aerospace industries and the orthopedic implant industry. The closed- or opendie operation uses cold forming, warm forming, and isothermal forming technologies to produce forgings with a plan view area of 40 square inches or less.

At FPD, processes and die geomet r ies are designed wit h adva nc ed 3 -D model i ng a nd state-of-the-art forging simulat ion sof tware packages (see Forging, March/Apr 2001, p. 37). The company supplies many airframe structures, like engine mounts, struts, nacelles, wings, fuselage, cargo handling and door assemblies. FPD also produces forgings for a range of orthopedic implants, including hip, knee, trauma and fixation devices, spinal components, and dental implants.

FPD uses two Electrotherm electrical rotary furnaces, a 1.6-m unit and a 1.2-m unit. The company recently ordered another 1.6-m rotary furnace.

Doncasters is an international engineering group that manufactures precision components and assemblies for the aerospace, industrial gas turbine, specialist automotive, and petrochemical markets. Doncasters Storms Forge in Springfield, MA, operates two 1.2-m Electrotherm electrical rotary furnaces.

Large rotary furnaces
The line of large ELRH electrically heated, rotary furnaces includes three models designed for use in a continuous forging process or a ring-rolling operation. The lineup includes models with hearth diameters of 3, 4.5 and 6.5 meters (see table for details).

These furnaces have been designed with a maximum working temperature of 1,200ºC (2,192ºF) for pre-heating jet engine disks and large turbine blades. They can be operated with air or protective atmospheres. They are suitable for forging Ti-based alloys, Nibased alloys and stainless steel.

Electrotherm claims the furnaces wi l l provide repeat ible temperature uniformity to ±5°C (±10°F) using silicon-carbide heating elements in several heating zones. Gas-fired radiant tubes also are available. Features include:

  • Continuous rotation feed to the press
  • Automatic option for integration in forging unit cell
  • Multi-zone heating
  • Reinforced steel outer frame
  • Shock absorbers to prevent vibration damage
  • SiC heating elements, installed vertically all around
  • Ceramic-fiber thermal insulation
  • SiC hearth tiles or cast metal trays
  • Digital temperature controllers and recorders with communication interface
  • R- or S-type thermocouples
  • T hyristor (single cycle) for linear power control
  • One slewing bearing
  • Automatic greasing system
  • Indexing system with digital display indication

Furnace construction meets requirements for work in protective atmosphere, and all are designed and built to comply with the NADCA P, AMS 2 750D, M I L -H- 6875H, and RPS953 aerospace standards.

Recently, Electrotherm installed two 4.5-meter rotary furnaces at a North American producer of steam and gas turbine blades and vanes for power generation. The company is expanding capabilities to include the manufacture of compressor and turbine discs, as well as fan blades for jet engines.

Electrotherm's North American regional sales manager is Joe Martin: Contact him at tel. 866-735-9712, or by email at [email protected].