ALD Two Chamber Vacuum Furnace | DualTherm®

2-Chamber Vacuum Furnace; DualTherm®

Direct cost advantages due to clean and dry parts (no surface

oxidation) after quenching.

No washing machine.

No maintenance or disposal of washing chemicals.

No complicated washing water chemistry.

Space and utility savings.

Significant Characteristics - DualTherm Operation

Furnace is switched off during idle periods (batch type furnace

heating up and cooling down time 2-3 hours)

Energy, cost saving.

Use of “vacuum” and inert gases, minimal quantities of carburizing

gas (l/h)

No fire precautions, no sprinkler required.

No automatic smoke vents in the roof.

No oil resistant floors and surfaces required.

No toxic gases with CO component.

No explosion hazards, no open flames.

Significant Characteristics - DualTherm Operation

multi-layer insulation

• low losses

• Insulation in segments around

Graphite heating

• high temperature uniformity

High number of Injecting tubes for vacuum carburizing

Option convective heating

Hearth Rails designed for applications >1000°C

Double thermocouple with additional conduit (comparison test)

Service door on the back of chamber

Significant Characteristics - DualTherm Treatment Chamber

• Charge weight 500 and 1000 kg (optional)

• Protective load transport with Fork lift system

Actuators and limit switches outside the chamber

• Short, consistent transport times

• Transport system tested in mass production

Significant Characteristics - DualTherm Internal Transport

• PC operating at the front side of the system

Database system for recipe storage

Recipes

Batch documentation, trending

Fault Recording

Siemens PLC type S7 300

Significant Characteristics - DualTherm System Control and Operation

Significant Characteristics - DualTherm External Transport

25% larger volume capacity.

External radial fan for homogeneous and uniform gas speed

distribution over the load.

Precise reproducibility via accurate control of carbon gas flow

All moving mechanical devices including the transport system

drives are outside the vacuum environment . They remain at room

temperature and are accessible for maintenance at any time.

These systems are never exposed to carburizing atmosphere or

vacuum.

Significant Characteristics - DualTherm

Significant Characteristics - DualTherm

Convective heating for faster cycles and minimized distortion and

faster to temperature uniformity.

Reversible gas flow during quenching.

Dynamic-Quench®

Can be integrated into automated lines.

DualTherm - Features

Significant Characteristics - DualTherm

Thermal and thermo-chemical heat treatment under vacuum or inert gas with

temperatures to 1250°C (2280°F).

Annealing of 150° – 1250°C in vacuum or partial pressure (N2, Ar, H2).

Hardening in vacuum or partial pressure

Vacuum Carburizing (Low Pressure Carburizing or LPC).

Carbo-nitriding in a vacuum

Brazing in vacuum or partial pressure

Combinations of methods such as soldering with subsequent hardening

Applications - DualTherm

A view from the quench chamber site glass

Note:

• 3 hearth rails

• Longitudinal heating elements

• 2 Forks (2200 lbs capacity)

Internal - DualTherm

Manually opening front door

Position workload in the chamber

Start automatic sequence

Evacuation begins within entry/quench chamber

After thermal treatment, automatic transport to quench

Automatic backfill to recipe defined pressure

Automatic Quench Fan Start

Transformation

Gas Quench Advantages – DualTherm

Shortly after cooling fan started Approximately 5 seconds later

DualTherm

Reversing Gas Flow Increased Quenching Uniformity

Modular Design Flexible and Expandable

Compact Chamber Design Short Gas Recycling Cycles,

reduced consumption

Gas flow

bottom -> top

Gas flow

top -> down

High Pressure Gas Quench Advantages - DualTherm

300

320

340

360

380

400

420

440

460

No reversing With reversing

Co

re h

ard

ne

ss

at

Mid

-to

oth

/ H

V3

0

Bottom min

Bottom average

Bottom max

Top min

Top average

Top max

Gas flow Gas flow

300

310

320

330

340

350

360

370

380

390

400

No reversing With reversing

Co

re h

ard

ne

ss

at

To

oth

ro

ot

/ H

V3

0

Bottom min

Bottom average

Bottom max

Top min

Top average

Top max

Gas flow Gas flow

300

310

320

330

340

350

360

370

380

390

400

No reversing With reversing

Co

re h

ard

ne

ss

at

Bu

lk / H

V3

0

Bottom min

Bottom average

Bottom max

Top min

Top average

Top max

Gas flow Gas flow

Bulk

Tooth

root

Mid-

tooth

Core hardness with and without reversing the gas flow

Modified SAE 5120

Option – Reverse Gas Flow

Convection ( 2 bar N2 )

(surface / core) Vacuum (surface / core)

Temperature dispersion: between surface und core one charge of bolts (540 kg gross, d = 25 mm)

0 60 120 180 240 300

800

600

400

200

0

Temperature (oC)

Time (min)

Advantages of the convective heating: shorter heating time uniform heating => reduced distortion

Option – Convection Heating

Internal access via full opening rear service door

No cables, hoses, motors or switches within the hot zone

Special tools for service and maintenance included

Transport motors, switches and adjustments from outside the

chamber

Maintenance - Service

High system availability

Low maintenance cost and spare parts requirements

Potential for high carburizing temperatures shortening process times

Low gas consumption during hardening

No cleaning of parts after heat treatment

No flame curtain

No risk of fire caused by oil fumes

Work cell friendly due to cold wall technology

Flexible use for different processes

Proven designs, used in mass-production on ModulTherm®

Customer Advantage

Customer Advantage

For more information contact us at:

ALD Vacuum Systems, Inc. 50477 Pontiac Trail Wixom MI 48393 (248) 956-7610

www.ALDVac.com