How does a high vacuum diffusion pump work without any moving parts?
A high vacuum diffusion pump operates without any moving parts by using the momentum transfer of vaporized oil molecules to entrain and remove gas molecules from the vacuum chamber. The pump functions through a combination of boiling oil, high‑velocity vapor jets, and condensation—creating pressure differentials that enable gas transport from the inlet to the exhaust. SUNFUN Group has been manufacturing diffusion pumps since 1986, applying precision machining to produce the critical components that support reliable, high‑vacuum performance in semiconductor and industrial applications.
Product Category 1: Oil Diffusion Pumps
Definition and Positioning
Oil diffusion pumps are high‑vacuum pumps that use vaporized oil as the pumping medium, generating a series of high‑velocity vapor jets that direct gas molecules toward the exhaust. These pumps are typically used in conjunction with mechanical roughing pumps to achieve pressures from 10⁻³ to 10⁻⁷ mbar. SUNFUN Group manufactures diffusion pump bodies and jet assemblies with precision‑machined components that optimize vapor flow and pumping speed. As oil diffusion pumps, these units have remained relevant in industrial vacuum technology due to their simplicity and cost‑effectiveness.
Core Functions and Technical Features
The diffusion pump operates on the principle of momentum transfer. Oil is heated to its boiling point in the pump's boiler section, creating a high‑pressure vapor. This vapor rises through the pump body and exits through a series of nozzles arranged in a jet stack, forming high‑velocity vapor jets. Gas molecules entering the pump from the vacuum chamber collide with these vapor jets and are entrained—carried downward toward the exhaust. The vapor and entrained gas molecules travel to the cooled pump walls where the vapor condenses, releasing the gas molecules to be removed by the backing pump.
The absence of moving parts is a defining feature of the diffusion pump. Operation is continuous as long as the oil is maintained at the correct temperature and cooling water circulates through the pump body. The jet stack geometry—including the number of stages, nozzle angles, and spacing—is critical for pump performance. SUNFUN Group's diffusion pumps are manufactured with precision‑machined jet assemblies that ensure consistent vapor flow patterns and optimal pumping speed. These high vacuum diffusion pump products are designed for long service life with proper oil maintenance.
Typical Application Scenarios
Oil diffusion pumps are used in applications requiring high vacuum without the need for oil‑free operation. Semiconductor manufacturing uses diffusion pumps for vacuum furnaces and some deposition processes. Industrial vacuum coating systems—including optical coating and metallizing equipment—employ diffusion pumps for their pumping speed and cost‑effectiveness. Research laboratories use diffusion pumps in applications where the oil contamination risk is acceptable and pumping speed is required.
Differentiation from Other Vacuum Pump Types
Oil diffusion pumps are distinguished from mechanical pumps by their operation without moving parts and their ability to achieve much lower pressures. Unlike turbomolecular pumps, diffusion pumps do not require high‑speed rotating assemblies, making them more robust and less susceptible to mechanical failure. The lack of moving parts also means diffusion pumps can be manufactured with simpler designs and lower initial cost.
SUNFUN Group's Manufacturing Capabilities
SUNFUN Group's diffusion pump production applies precision machining and quality control appropriate for vacuum applications. Our 0.001‑mm precision machining ensures that jet stack components meet dimensional requirements for optimal vapor flow. Through our open innovation ecosystem, established in partnership with governments, enterprises, universities, and institutions, we maintain knowledge of evolving diffusion pump designs and applications for diffusion vacuum pump products.
Diffusion Pump Specifications
- Pressure range: 10⁻³ to 10⁻⁷ mbar
- Pumping speed: 500 to 10,000 L/s (air)
- Oil type: Hydrocarbon or synthetic
- Heating: Electrical heating elements
- Cooling: Water or air cooled
- Jet stages: 3 to 4 stages typical
Product Category 2: Diffusion Pump Jet Stacks and Nozzle Assemblies
Definition and Positioning
Diffusion pump jet stacks and nozzle assemblies are the critical components that generate the high‑velocity vapor jets responsible for gas entrainment. These assemblies consist of concentric nozzles arranged vertically, with each stage providing progressively higher pumping speed. SUNFUN Group manufactures jet stacks with precision‑machined nozzles that ensure consistent vapor flow patterns and optimal pump performance. As oil diffusion pumps components, these assemblies are essential for pump efficiency.
Core Functions and Technical Features
The jet stack is the heart of the diffusion pump, converting thermal energy into directed vapor flow. Boiler section pressure drives vapor upward through the jet stack, exiting through each nozzle stage. The nozzle geometry controls the vapor velocity and direction, with each stage designed to entrain gas molecules at different pressures. The top stage handles the lowest pressure and is critical for ultimate pressure performance. Lower stages handle higher pressures and contribute to pumping speed.
Nozzle design is precise and application‑specific. The nozzle angle, gap width, and diameter determine the vapor jet velocity and entrainment efficiency. SUNFUN Group's jet stacks are manufactured with the dimensional accuracy required for consistent pump performance. Our 0.001‑mm precision machining ensures that nozzle openings and spacings meet design specifications. These high vacuum diffusion pump components must be manufactured to tight tolerances to maintain pump efficiency.
Typical Application Scenarios
Jet stacks and nozzles are used in every diffusion pump, with the specific configuration tailored to the application requirements. High‑speed pumps use multi‑stage jet stacks with optimized nozzle geometries. Research applications may require specialised nozzle designs for specific gas compositions.
Differentiation from Other Components
Jet stacks differ from other pump components in their functional role—they are the active elements that create the vapor jets. The precision of the jet stack determines pump performance, and any damage or wear affects pump efficiency.
SUNFUN Group's Precision Manufacturing
SUNFUN Group's jet stack and nozzle production applies precision machining and quality control appropriate for vacuum pump components. Our in‑house institute and talent academy provide technical expertise in jet stack design and manufacturing. Our accredited technology enterprise status—demonstrated through national‑level R&D tasks and projects commissioned by the NDRC, MOST, and MIIT—supports quality systems for diffusion vacuum pump components.
Jet Stack Specifications
- Stages: 3 to 4 stages typical
- Nozzle angles: 45° to 60° standard
- Materials: Stainless steel, brass
- Surface finish: Ra ≤ 1.6 µm internal
- Installation: Concentric, with precise alignment
- Inspection: Dimensional verification of all nozzles
Product Category 3: Diffusion Pump Heating and Cooling Systems
Definition and Positioning
Diffusion pump heating and cooling systems maintain the temperature conditions required for continuous pump operation. The heater maintains oil at the correct boiling temperature, while the cooling system condenses vapor after it exits the jet stack. SUNFUN Group manufactures heating and cooling components that support reliable diffusion pump operation, applying precision machining to produce components that meet thermal requirements.
Core Functions and Technical Features
The heating system in a diffusion pump provides the thermal energy required to vaporize the pump oil. Electrical heaters are immersed in the oil reservoir or attached to the boiler section, maintaining the oil at its boiling temperature. The heating system must provide consistent heat input to maintain stable vapor pressure. The cooling system condenses vapor after it exits the jet stack, preventing vapor migration to the vacuum chamber. Water cooling is standard for most diffusion pumps, with cooling coils or jackets integrated into the pump body.
The design of heating and cooling systems must accommodate thermal expansion and contraction without stressing the pump body. SUNFUN Group's components are manufactured with precision to ensure proper fit and thermal performance. These oil diffusion pumps are designed to maintain stable temperature conditions for reliable operation.
Typical Application Scenarios
Heating and cooling systems are used with every diffusion pump. The specific heating and cooling requirements depend on the pump size, oil type, and application environment.
Differentiation from Other Pump Systems
Diffusion pump heating and cooling systems differ from those of other pump types in their thermal requirements. The heating system must maintain oil temperature within a narrow range for stable operation, while the cooling system must remove the heat energy added by the heater.
SUNFUN Group's Component Manufacturing
SUNFUN Group manufactures heating and cooling components for diffusion pumps, supporting our complete vacuum pump product line. Through our open innovation ecosystem, we maintain knowledge of evolving thermal management requirements for high vacuum diffusion pump products.
Key Specifications Comparison
| Parameter |
Oil Diffusion Pump |
Turbomolecular Pump |
Ion Pump |
| Moving parts |
None |
High‑speed rotor |
None |
| Pressure range |
10⁻³ – 10⁻⁷ mbar |
10⁻³ – 10⁻¹⁰ mbar |
10⁻⁶ – 10⁻¹¹ mbar |
| Oil contamination |
Yes |
Minimal |
No |
| Pumping speed |
High |
Moderate |
Low |
| Cost |
Moderate |
High |
High |
A high vacuum diffusion pump operates without any moving parts through the momentum transfer of vaporized oil molecules, using a heated boiler section, high‑velocity vapor jets, and a cooled pump body to entrain and remove gas molecules from the vacuum chamber. SUNFUN Group manufactures complete diffusion pump solutions, including pump bodies, jet stacks, and thermal management components, applying precision machining and quality control developed over four decades of experience. Our 0.001‑mm precision machining ensures that jet stack components meet dimensional requirements for optimal vapor flow and pumping speed. Through our in‑house institute, talent academy, and open innovation ecosystem—established in partnership with governments, enterprises, universities, and institutions—SUNFUN Group maintains the technical expertise required for oil diffusion pumps in semiconductor, research, and industrial vacuum applications.
Frequently Asked Questions
Q1: How does a diffusion pump achieve high vacuum without moving parts?
The diffusion pump uses high‑velocity vapor jets generated by boiling oil to entrain gas molecules through momentum transfer. Gas molecules collide with the vapor jet and are carried toward the exhaust, where the vapor condenses on cooled surfaces and the gas is removed. The absence of moving parts is a defining feature of oil diffusion pumps.
Q2: What pressure range can an oil diffusion pump achieve?
Oil diffusion pumps typically achieve pressures from 10⁻³ to 10⁻⁷ mbar when used with a suitable roughing pump. The ultimate pressure depends on the oil type, pump design, and system conditions. High vacuum diffusion pump products can achieve the lower end of this range with proper operation.
Q3: What are the advantages of a diffusion pump over a turbomolecular pump?
Diffusion pumps offer lower initial cost, simpler construction, higher pumping speed for their size, and robust operation without high‑speed rotating assemblies. However, they introduce oil contamination risk. Diffusion vacuum pump products are preferred for applications where oil contamination is acceptable and pumping speed is required.
Q4: What quality controls apply to SUNFUN Group's diffusion pump manufacturing?
SUNFUN Group applies material certification, dimensional verification, surface finish measurement, and performance testing to all diffusion pump production. Our accredited technology enterprise status supports comprehensive quality systems for oil diffusion pumps, ensuring consistent pump performance and reliable operation.
English
日本語
عربى
中文简体
