The working principle of brazing furnace

The working principle of brazing furnace

At present, the development of the gas protection brazing furnace, generic mostly imported products. Which is used for aluminum alloy heat sink, and other aluminum brazing furnace and strikingly similar to imported products, this is the result of controlled by Noclock process, only some use manufacturer in order to reduce investment requirements development unit is simplified. If a manufacturer will solder spray, dry air blown away, workpiece processing outside the furnace. Handle directly into the brazing furnace after welding. Even so, our country the majority of users of the equipment investment is difficult to bear. Thus, a company in China in order to adapt to the requirement, developed a single chamber discontinuous brazing furnace, its investment is greatly reduced. But lower efficiency and quality and stability, can say, this is no way to solution. Brazing of aluminum products for high temperature control precision and the uniformity of the heating demand. Developing the brazing furnace for domestic research units, difficulty is very big still. To this end, a domestic research units have adopted a Japanese company and cooperation way, but because of its technology and key components are from Japan, so the cost reduction is not much, the price advantage is not big. Develop performance meet the welding requirements, at the same time, the price is acceptable for users on the brazing furnace gas protection, only on the basis of absorbing foreign advanced technology, the road go localization. Now a certain institute is to take this way. Steel parts brazing furnace compared with imported products, there are different:
(1) import brazing furnace protective atmosphere is mostly for liquefied petroleum gas. And now most of our country by decomposition of ammonia gas. In fact, in the western developed countries protect atmosphere basically USES two: a, liquefied petroleum gas. B nitrogen-based atmosphere. Most prospects of nitrogen based atmosphere. Now not only threatens our country's energy crisis, but also threatens the entire world. We know that the air contains 78% nitrogen, is inexhaustible. Now most also USES the ammonia decomposition gas in our country, the main reason there are two: one is the decomposition of ammonia gas was simple; Second, the publicity of nitrogen based atmosphere, the masses of users do not know much about this, has affected the promotion.
(2) domestic protective atmosphere generator are placed outside the furnace. Outside the furnace gas protection to the furnace protection. And brazing furnace introduced into China the most protective atmosphere generator in the furnace, the advantages of many, such as saving area, save energy, simplify operation, so as to save investment and so on, this way should be vigorously promoted.
(3) heating element: during a visit to import brazing furnace and anatomic abroad, most of the heating element adopts two kinds, one is the resistance wire, 2 it is tubular heater. Our country is most use SiC rods.
(4) the furnace structure: imported cost brazing furnace, with oil heat resistant and heat preservation materials of masonry furnace for, belong to the horse fee structure. But almost no this kind of furnace in our country adopt the ma fee structure of heat resistant steel. In the transmission structure, our country's research unit should be of kung fu. Now regardless of mesh belt transmission or ship plate, have obvious disadvantages. According to information, the overseas developed a ceramic mesh belt, it does not change the way of transfer, still make the operation workers; No metal mesh belt and thermal creep and crystal growing concern. This mesh belt such as developed, will reduce the running cost of the brazing furnace.
In short, our country in gas shielded continuous aluminum brazing furnace home and abroad have a certain gap, in steel, stainless steel, copper and other materials used for the brazing furnace home and abroad the gap is not big, research efforts are also increasing.

Vacuum Brazing Furnace Hot Zone Temperature Control Partition

Vacuum Brazing Furnace Hot Zone Temperature Control Partition

In the heating chamber vacuum brazing furnace to form a magnesium-containing atmosphere to protect the exposed aluminum surface is no longer oxidation. On the other hand penetrate through an alumina film slit aluminum surface, forming alloy partially melted, further tunneling oxide film. Produce liquid solder wetting and flow on non-fresh surface oxide film, and filled weld formed under the action of capillary forces the fillet. Aluminum vacuum brazing must be seen in a high vacuum state by the above description, generally in 10-3Pa magnitude. If the vacuum of less than 10-3Pa, then immediately combined with magnesium and evaporated vacuum brazing furnace, oxygen and moisture paper trace of the child, can not form a magnesium protective atmosphere, so just exposed to the fresh aluminum oxide surface and immediately, if not removing the oxide film, it will not cause liquid solder wetting and flow. For the radiator, the radiator due to the relatively large surface area, the amount of gas adsorbed lot, in the heating process will be a lot of deflation, the vacuum was reduced. To Yasumasa vacuum brazing furnace, vacuum, and therefore must choose a larger pumping speed of the vacuum unit (pump rate: 5.0 × 10-4Pa atmosphere to no more than 30min) Al-Si-Mg solder melting point close to the melting point of aluminum , so its brazing temperature range is very narrow, generally between 595 ~ 615 ℃. As for the heat exchanger type structure is generally large size and spatial distribution are very uneven and mostly thin-walled material, and therefore requires uniformity of temperature vacuum furnace heating zone is very strict, not more than ± 3 ℃ (space heaters, nine temperature), so the need for vacuum brazing furnace hot zone temperature control partition. Rain increase 200 ℃ oven. Incubated for 60 minutes. Vacuum below 5 * 10-2.

High temperature vacuum brazing furnace

High temperature vacuum brazing furnace

High temperature vacuum brazing furnace is used in copper alloy, stainless steel, high temperature alloy, heat resistance alloy vacuum brazing process, also it is used in refractory alloys and dissimilar metals which contain Ti, Zr, niobium, Mo elements vacuum brazing process. It is widely used in EGR cooler, diamond cutting tool, Fe-Cr-Al alloy, plate-fin heat exchangers, oil cooler brazing process.
During brazing process, work pieces under vacuum atmosphere or protection atmosphere condition, this process can achieve no oxidation, tiny deformation, no air hole, no flux slag, bright surface, no pollution advantages.
The control system was controlled by PLC; temperature was controlled by intelligent temp controller, accurate control, and high automation. User can choose auto or manual undisturbed switching to operate it; this furnace has abnormal condition alarming function, easy to operate.

Vacuum brazing furnace safety rules

Vacuum brazing furnace safety rules

You know the safety rules vacuum brazing furnace, what are you? We must be mastered in order to work in a vacuum brazing furnace before the operation of its security procedures, so as not to affect the course of work. With a look!
1. Before using this device, you should be familiar with equipment operating instructions and temperature indication regulator, in order to achieve the purpose of the proper use of various instruments.
2, ammonia is a toxic gas odor stimulus, should prevent leakage, non-human direct contact with liquid ammonia, to avoid frostbite.
3, always check the device's pneumatic system tightness, ammonia leak irritating odor, and decomposition gas is colorless and odorless, but explosive, pay attention to safety.
4, antifreeze splash operatives wearing masks and gloves when replacing ammonia bottle.
5, open intake must be slow when ammonia valve to prevent a large number of liquid ammonia into the device and into the ammonia pressure can not be controlled.
6, non-operatives are free to modify the parameters temperature control instrumentation.
7, the device should be checked before power cooling water is smooth.
8, prohibited operatives directly with hydrogen to discharge air inside the muffle.
9, prohibited the feeding stage ignition mouth shut.
10, the device temperature, when cooled, in strict accordance with heating, cooling curve execution.
11, the operator at the time of welders, the workpiece should be placed on the transfer belt in the middle.
12, the apparatus is in use, is strictly prohibited open on both sides of the furnace cover plate.
13, equipment operation, if an alarm occurs should be viewed troubleshooting.
14, non-smoking in the workplace. Working around the venue should the fire ban, Waterproof area with fire extinguishers.
15, prohibited device directly facing the operator unloading port work.
16. The equipment enclosure must be grounded to avoid electrical accidents.
17, the device cut off the power during maintenance overhaul.
18, decomposing furnace in the heating process, must not exceed 850 ℃, the event should be promptly cut off the power supply to avoid stove burned.
19, must be inserted into the bottom of the dryer temperature thermocouple tube to prevent over-temperature thermal burn out of control equipment.
20, if the analyzer displays accurate system is working properly, but the products reach the index, it can be considered a catalyst, whether molecular sieve has expired. Catalyst, molecular sieve life of more than 2 to 3 years. If the confirmation has expired, you need to replace the catalyst, molecular sieve, which must have professional and technical personnel.

Vacuum Brazing Welding Equipment Fixture Design

                                     

Vacuum brazing fixture and general design principles

Brazing parts shall be assembled in positioning vacuum brazing, the parts of the question in order to ensure mutual position and brazed joints required to ask gap. Brazing the brazing jig involves fixing parts, assembly, into the furnace, brazing, baked whole process. Jig is reasonable and practical directly affect the quality of brazing. Common fixture design principles and requirements also apply to brazing fixture design, such as the fixture system to have a certain precision; fixture system to have a certain rigidity to overcome the deformation process; fixture system to be compact, simple shapes, handling and convenient features in addition to considering the above principles, brazing fixtures as well as its own characteristics, generally speaking brazing fixture design should also consider the following factors:
(1) the clamp material to be able to withstand the brazing temperature, without loss of strength , deformation and release gas, difficult to produce an alloy react with welding pieces;
(2) pay attention to fixtures and parts of thermal expansion and contraction, at the brazing temperature, to ensure the braze parts with suitable joint gap; and
(3) the clamp To ensure heat conduction soldering zone due to heat transfer on the stability of the heated components interfere with the minimum cooling, and without prejudice to the flow of the solder.