900×900×1200mm Effective Heating Zone | Vacuum Aluminum Brazing Furnace | Vacuum Brazing System for Aluminum Heat Exchangers & Waveguide Components

1. Product Overview

This single-chamber horizontal double-door vacuum aluminum brazing furnace is specifically designed for vacuum brazing of aluminum heat exchangers, waveguide components, and other parts. Featuring a double-layer water-cooled furnace body, six-zone independently controlled heating chamber, domestic high-quality vacuum pumps, and external circulation cooling system. Typical applications include high-volume, high-consistency vacuum brazing production lines for aluminum plate-fin heat exchangers, aluminum waveguides, and automotive air conditioning components.

2. Industry Challenges & Root Cause Analysis

Insufficient brazing temperature uniformity:Aluminum brazing requires extremely high temperature uniformity – excessive differentials cause localized overheating or incomplete filler metal melting. Root cause: irrational heating element layout, insufficient zone division, and inadequate heat shield design.

Unstable vacuum affects brazing quality:Magnesium vapor and outgassing products contaminate the vacuum system during brazing – causing vacuum fluctuations. Root cause: lack of effective magnesium collector and fore-line filtration protection.

Low cooling efficiency and long cycle time:Natural cooling is slow – significantly reduces equipment utilization. Root cause: lack of forced external circulation gas cooling and efficient heat exchangers.

Low process control automation:Multiple manual operations – parameter settings and monitoring rely on experience – poor batch consistency. Root cause: control system lacks programmable automatic operation and interlock protection.

Inadequate equipment safety protection:Vacuum, heating, and cooling subsystems lack fault interlock protection – safety hazards exist. Root cause: lack of comprehensive electrical-mechanical interlocks and fault alarm systems.

3. Solution

3.1 Uniform Heating with Six-Zone Independent Control:Effective heating zone 900×900×1200mm – max load 800kg. Wide-band nickel-chromium alloy heating strips – six zones independently controlled – temperature control accuracy ≤±1℃ – empty furnace uniformity at 600℃ nine-point measurement ≤±3℃. Heating chamber features stainless steel reflector + single-layer stainless steel frame square box structure – front/rear stainless steel protective plates prevent workpiece contact with heating elements. Furnace bed made of 304 stainless steel – minimizes high-temperature deformation.

3.2 High Vacuum System with Magnesium Collector:Ultimate vacuum ≤6×10⁻⁴Pa (empty, cold, cleaned) – working vacuum at 610℃ ≤1.3×10⁻³Pa – pressure rise rate ≤0.2Pa/h. Vacuum system: H-150 slide valve pump + ZJP-1200 Roots pump + KT-1000 diffusion pump + BDR60 maintenance pump – with high vacuum gate valve and cold trap. Magnesium collector features grid-type water-cooled copper tube with copper fins – effectively intercepts magnesium oxide powder – protects vacuum pumps.

3.3 Negative Pressure External Circulation Rapid Cooling System:Uses nitrogen negative pressure external circulation cooling – equipped with circulating cooling fan, external pipes, impeller, and heat exchanger. Automatic gas charging pipe supplies cooling gas – automatically closes charging valve when pressure reaches preset value – reopens when below preset. Enables controllable rapid cooling – shortens production cycle.

3.4 Fully Automatic PLC Control System:Omron CPE-1 PLC + 10-inch touchscreen + Eurotherm temperature controllers (3504+PT100). 6 K-type dual-core thermocouples for temperature measurement + 9 uniformity measurement thermocouples + 6 pluggable workpiece thermocouples for program control – set workpiece temperature for automatic heating and holding – reduces manual intervention. Full automatic/manual interlock dual-mode control. Digital vacuum transmitter with range atmospheric to 10⁻⁵Pa.

3.5 Multiple Safety Interlock Protections:Heating automatically stops if vacuum falls below preset – automatically restarts when restored. Thermocouple failure automatically cuts heating with audible/visual alarm. All vacuum valves close on power failure – maintains equipment seal. Cooling water flow/pressure below set point triggers automatic shutdown with alarm. Heater over-temperature/over-current/over-voltage and pump overload protections with alarms. Safety valve prevents furnace overpressure.

4. Technical Specifications

5. Selection Guide

5.1 Recommended Scenarios

• High-volume vacuum brazing of aluminum plate-fin heat exchangers

• High-precision brazing of aluminum waveguides and automotive air conditioning components

• Processes requiring six-zone uniform heating, high vacuum, and rapid cooling

5.2 Key Selection Considerations

1. Workpiece size and load: Verify maximum dimensions fit 900×900×1200mm zone – total weight ≤800kg

2. Process temperature: Maximum operating 700℃ – confirm brazing temperature within range

3. Vacuum requirements: Ultimate ≤6×10⁻⁴Pa – meets high-vacuum aluminum brazing requirements

4. Utilities: 30m³/h cooling water (0.2-0.25MPa, inlet ≤32℃), 0.6-0.8MPa compressed air, 380V/230KVA power

5. Lifting equipment: 10-ton overhead crane required

6. FAQ

Q1: How is furnace temperature uniformity ensured?

A: Six-zone independent control – wide-band nickel-chromium alloy heating elements – four-layer 304 stainless steel heat shield – front/rear stainless steel protective plates. Eurotherm controllers with PID regulation – empty furnace nine-point uniformity at 600℃ ≤±3℃ – control accuracy ≤±1℃.

Q2: What is the function of the magnesium collector?

A: Magnesium vapor during aluminum brazing produces magnesium oxide powder. The grid-type water-cooled copper tube + copper fin magnesium collector effectively intercepts magnesium oxide particles – prevents them from entering vacuum pumps – protects long-term vacuum system operation.

Q3: How long is the evacuation time?

A: Empty furnace from atmosphere to 2×10⁻³Pa in ≤80 minutes (diffusion pump preheated, valve fully open) – meets aluminum brazing requirements for rapid vacuum establishment.

Q4: How does the cooling system work?

A: Nitrogen negative pressure external circulation cooling – automatic gas charging pipe supplies cooling gas – valve automatically closes at preset pressure – reopens when below preset. Circulating cooling fan + heat exchanger provides gas circulation cooling – significantly reduces cooling time.

Q5: How do workpiece thermocouples participate in control?

A: 6 pluggable workpiece thermocouples – set workpiece temperature on touchscreen – system automatically heats and holds based on actual workpiece temperature – no manual intervention – improves process consistency and automation.