(1) Induction brazing systems can now be more compact using new power supplies that produce any desired frequency and new magnetic flux concentrators to control heat patterns. (2) Computer simulations can help design induction brazing coils and concentrators for specific applications like brazing pipes to tubes or aluminum heat exchangers. (3) New magnetic materials like Fluxtrol A improve process quality and efficiency for brazing various metals like copper, aluminum, and steel.

1. 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

2. 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

3. Pipe to Tube Induction Brazing Installation
using “Horseshoe-Hairpin” Coil
Connection Block
Pipe
Joint
Fluxtrol A Magnetic
Flux Controller
Copper Coil
Tube
Header
Body

4. 3D Computer Simulation of AL Pipe
to Tube Brazing
Copper Coil
Pipe
Top Concentrator
Tube
Central concentrator
Header
Bottom concentrator

5. Example of Computer-Assisted
Design of Brazing Inductor
Brazing of Pipe to Nipple of Aluminum Heat Exchanger
Pipe
Tube
Header
Fluxtrol
controller
system

6. Two-Station Induction Installation for Manual
Brazing
Two Transistor generators
Heat Station
10 kW 66 kHz

7. Brazing of Copper Crossovers to Heat
Exchangers
Tinned steel plate Crossover L-shaped
Inductor copper
controller

8. Power Supply for Brazing
Manufacturer – Freal, Ltd., St. Petersburg
Generator Power 10 kW; Frequency 66 kHz; Weight 12 kg
Cooling – Forced Air

9. 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

10. Brazing of Heavy Copper Bussbars
for Nuclear Plants
Two-inductor system for balanced heating of parts
Power 100 kW; Frequency 10 kHz
Fluxtrol
concentrators

11. Brazing of Heavy Copper Bussbars
for Nuclear Plants
Fluxtrol controllers
Close-up of induction coil attached to a special transformer
with amorphous magnetic core

12. Even Small Concentrators Drastically
Improve Coil Performance
Concentrators
Brazing of steel tube to Brazing of hard plates to mill bits
profile with clamshell inductor Red spot – laser pointer of IR pyrometer

13. 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