INDUCTORS

WITH MAGNETIC FLUX CONTROLLERS

FOR NEW INDUCTION BRAZING

INSTALLATIONS

Dr. V. Nemkov1 and Dr. V. Vologdin 2

(1) Centre for Induction Technology, USA

(2) FREAL, Ltd., Vologdin High Frequency Currents Institute,

Sankt Petersburg, Russia

Induction Brazing Updates

• New compact power supplies with any

desired frequency

• New fluxes and filler metals including

amorphous materials

• New magnetic materials for heat pattern

control

• Computer simulation design

Pipe to Tube Induction Brazing Installation

using “Horseshoe-Hairpin” Coil

Connection Block

Pipe

Tube

Header

Body

Joint

Copper Coil

Fluxtrol A Magnetic

Flux Controller

3D Computer Simulation of AL Pipe

to Tube Brazing

Central concentrator

Header

Top Concentrator

Tube

Pipe

Copper Coil

Bottom concentrator

Example of Computer-Assisted

Design of Brazing Inductor

Brazing of Pipe to Nipple of Aluminum Heat Exchanger

Pipe

Tube

Header

Fluxtrol

controller

system

Two-Station Induction Installation for Manual

Brazing

Two Transistor generators

10 kW 66 kHz Heat Station

Brazing of Copper Crossovers to Heat

Exchangers

Tinned steel plate Crossover L-shaped

controller Inductor copper

Power Supply for Brazing

Generator Power 10 kW; Frequency 66 kHz; Weight 12 kg

Cooling – Forced Air

Manufacturer – Freal, Ltd., St. Petersburg

Brazing of Heavy Copper Bussbars

for Nuclear Plants

Length up to 4 metres, cross-section up to 3000 mm2

More than 500 joints per coil

Brazing of Heavy Copper Bussbars

for Nuclear Plants Two-inductor system for balanced heating of parts

Power 100 kW; Frequency 10 kHz

Fluxtrol

concentrators

Brazing of Heavy Copper Bussbars

for Nuclear Plants

Close-up of induction coil attached to a special transformer

with amorphous magnetic core

Fluxtrol controllers

Even Small Concentrators Drastically

Improve Coil Performance

Concentrators

Brazing of steel tube to

profile with clamshell inductor

Brazing of hard plates to mill bits

Red spot – laser pointer of IR pyrometer

Conclusions

• Compact installations for induction brazing processes are possible with new power supplies

• Magnetic Flux Concentrators play big role in improvement of process quality and efficiency

• Fluxtrol A, 50 and Ferrotron 559 materials perform well in brazing of copper, aluminum and steel components