What vacuum pumps are used in vacuum brazing furnaces?

03-21-2025       Author: KJ technology

There are various types of vacuum pumps commonly used in vacuum brazing furnaces, and the specific selection depends on the required vacuum degree, process requirements, and overall equipment configuration. The following are commonly used types of vacuum pumps in vacuum brazing furnaces:

Mechanical pump (pre stage pump):

Function: As a preliminary pumping device for vacuum systems, it is used to reduce the gas pressure inside the furnace to a certain level, providing working conditions for subsequent vacuum pumps (such as Roots pumps, diffusion pumps, etc.).

Features: Simple structure, easy maintenance, fast pumping rate, but relatively low ultimate vacuum degree.

Roots pump:

Function: On the basis of mechanical pumps, further improve the vacuum degree. The Roots pump rotates inside the pump chamber through two "8" - shaped rotors, drawing gas in from the inlet and compressing it to the outlet.

Features: Large pumping capacity, simple structure, easy maintenance, suitable for medium and high vacuum range.

Diffusion pump:

Function: Plays a crucial role in achieving high vacuum levels. The diffusion pump uses steam flow (such as oil vapor) as the working medium to bring gas molecules out of the furnace through high-speed steam flow, achieving a high vacuum state.

Characteristics: It can achieve extremely high vacuum degree, but the pumping rate is relatively low and requires preheating time.

Molecular pump:

Function: Widely used in the field of ultra-high vacuum. Molecular pumps use high-speed rotating rotors to transfer gas molecules from the inlet to the outlet, achieving ultra-high vacuum.

Features: Low ultimate pressure, fast pumping speed, especially suitable for occasions with extremely high vacuum requirements.

In practical applications, vacuum brazing furnaces may adopt a combination of single-stage or multi-stage vacuum pumps to meet different process requirements. For example, common combinations include mechanical pump+Roots pump, mechanical pump+Roots pump+diffusion pump, etc.

In addition, there are some special types of vacuum pumps, such as dry screw vacuum pumps, claw type dry vacuum pumps, etc., which also have unique advantages in certain specific situations. For example, dry screw vacuum pumps have the advantages of no oil pollution, low noise, and low vibration, making them particularly suitable for situations that require high cleanliness.

When choosing a vacuum pump, it is necessary to comprehensively consider factors such as the vacuum degree requirements of the equipment, process characteristics, cost budget, and maintenance convenience. At the same time, attention should also be paid to the brand, performance, reliability, and after-sales service of the vacuum pump to ensure that the selected vacuum pump can meet the actual needs of the vacuum brazing furnace.