Continuous brazing furnace

Machine Overview

The continuous brazing furnace is a modern industrial equipment for producing aluminum radiator and condenser. It realizes large-scale production in the working mode of continuous brazing. Compared with vacuum furnace and box brazing furnace, its production efficiency has not only increased many times, but also its welding cost has been greatly reduced

In this continuous production mode of aluminum brazing furnace, there is inert gas in the furnace to protect the product from oxidation at high temperature. The oxygen analyzer analyzes the oxygen content in the furnace in real time and transmits the data to the display screen, so that engineers can clearly know the operation status of the brazing furnace

The brazing furnace is fully automatic, in which several parts realize different functions, such as high-temperature degreasing, automatic flux spraying, aluminum product drying, gas shielded aluminum brazing, efficient cooling and intelligent control

Working principle of continuous furnace brazing

This brazing furnace uses high temperature to weld more than two aluminum parts into one part. This process usually requires several key steps,

• Aluminum materials need to be spraying with nocolok flux before welding, and its ratio is usually 3:100. 3kg flux needs to be add with 100 water. If necessary, parts need to be degreased at high temperature before spraying, because grease and stains on the part surface will affect the welding effect.

• Before welding, aluminum products must undergo 100% drying, as any moisture will vaporize during the high-temperature welding process, polluting the atmosphere inside the furnace and affecting the quality of brazing.

• The temperature control of continuous furnace brazing is the key technology. If the temperature is too low, the welding effect will be poor, and if the temperature is too high, the fin will be break. Therefore, it is very important to have an experienced aluminum brazing engineer.

• Nitrogen control: During the high-temperature brazing process, nitrogen must be transported inside the furnace, usually at a flow rate of 80-120 m³ per hour, and engineers need to check the nitrogen flow meter every hour because pressure changes in the liquid nitrogen tank can affect the flow rate.

Benefits of continuous brazing furnace

1. Mass production

The width of the conveyor belt is 1200mm. This width can be useing to place two automobile microchannel condenser or three rows of small displacement automobile radiator, which means that this brazing furnace can be efficiently production in large scale

2. Accurate temperature control

The length of the brazing zone is usually 8-12 meters. Each meter has two independent temperature control zones. This distributed temperature control can effectively increase the temperature uniformity. Even if the temperature of one control zone fails, it will not affect the quality of the aluminum brazing furnace

3. Multi product welding without additional cost

This continuous brazing furnace can weld all products of aluminum materials, such as automobile engine radiator, microchannel condenser, air conditioning heater, transmission oil cooler, battery cooling plate, etc., and welding different products does not require additional mold change and other costs

4. Fully intelligent control method

This brazing furnace have a 10 inch touch screen and a built-in logically clear operation page. Engineers can preset multiple steps to achieve one click heating and one click cooling, and allow users to store the production processes of different products, easily achieving continuous improvement of brazing processes

Technical parameters of continuous brazing furnace

No.	ITEM	DATA
1	Nitrogen consumption	60m³/h
2	Tunnel width	1000mm
3	Tunnel height	250mm
4	Drying temperature	300 ℃
5	Brazing temperature	625℃
6	Cooling method	air cooling
7	Solder flux	NOCOLOK
8	Production speed	Max 1800mm/min
9	Maximum temperature	720 ℃
10	Spraying method	diaphragm pump
11	Heating method	electricity and natural gas
12	Delivery time	95 days

Mafu design of continuous brazing furnace

MaFu is a key component of this equipment, which consists of two stainless steel 316L materials spliced together. The bottom is 10mm and the top is 8mm. The two plates are welded using argon arc welding. As MaFu needs to withstand a high temperature of 650 ℃, a senior welding engineer is required to be competent for this job, otherwise it will affect the service life of MaFu.

The width and height of the muffle are design according to the user’s requirements. At present, the most popular dimensions are 1200mm in width and 250mm in height, which can meet 98% of the products on the market. However, some factories produce small-scale products, such as washing machine drying heaters, gearbox oil cooler, automobile evaporators, etc. These products are generally small in size, and the width of the mafu is 500mm enough.

The interior of mafu requires pipelines for nitrogen transportation and oxygen analysis instruments, which need to be install before welding After several design improvements, our Mafu design of continuous brazing furnace has arranged nitrogen pipes reasonably, reducing the use of nitrogen by 40% and effectively reducing operating costs.

Other types of aluminum brazing furnaces

Aluminum brazing process

The aluminum brazing process is to melt a complex aluminum product at high temperature from a base material, and then cool it to form a complete part. This process is called aluminum brazing process. The most commonly used aluminum materials in this process are 3003, 6061, 4343/3003/4343, 7072/3003/4343, 4045, 4143, etc. However, the materials used in different products may be different. Below, we will explain their differences using two products.

Automobile microchannel condenser

The material of the collector pipe is 3003, but a layer of zinc material is sprayed on the outside of the round pipe. Zinc material will melt in the high temperature of the continuous brazing furnace and then weld with the microchannel aluminum pipe.

The material of microchannel aluminium tube is 6061. The production process of this tube is high-temperature extrusion. It will not melt during aluminum brazing, which means that this tube has no welding ability.

The material of aluminium fin is 4343/3003/4343, and the thickness of this material is usually 0.1mm. The thickness of 4343 material on both sides is 0.01mm. In high temperature environment, 4343 material will be completely fuse, and it will be welding with micro channel tube.

Note: When two materials come into contact, one material must have the ability to melt, otherwise they cannot be effectively welding

Plate and Bar Heat Exchanger

Many parts of this product are assemble by building blocks to form an aluminum core. It has many parts, such as bar, rod, inner fin, outer fin, flat plate, etc. Only the material of the plate is 4343/3003/4343, and the other materials are all 3003 or 6061.

Note: This product is welding by a continuous brazing furnace, so before assembling the aluminum core, the aluminum plate needs to be spraying with brazing flux first, otherwise the welding will leak.