Types of vacuum generators
Vacuum generators can be classified according to three main criteria:
- Number of vacuum stages
- Vacuum generation principle
- Mounting configuration
Single-stage and multi-stage vacuum generators
Depending on performance requirements, a vacuum generator can be designed as single-stage or multi-stage.
- Single-stage generators create vacuum in one step. They offer a simple and compact solution, suitable for standard applications with moderate vacuum requirements.
- Multi-stage generators increase vacuum progressively through multiple stages. This allows higher vacuum levels and improved efficiency, even at lower supply pressures.
Multi-stage technology is particularly useful when higher suction performance is required without increasing compressed air consumption.
Venturi-based vacuum generators
Most vacuum generators operate according to the Venturi principle, based on Bernoulli’s law. When compressed air flows through a narrowed nozzle, its velocity increases and pressure decreases, creating a low-pressure area that generates suction.
Venturi vacuum generators are suitable for the 80% of industrial applications thanks to their simple design, reliability and flexibility.
For very specific applications, such as handling delicate or highly porous materials, alternative vacuum technologies (such as contactless vacuum grippers) may be considered.
Single and manifold-mounted vacuum generators
Vacuum generators are available in two main mounting configurations:
- Single mounting generators are ideal when a single vacuum point is required. They offer a cost-effective and straightforward solution.
- Manifold-mounted generators are designed for systems where multiple vacuum units must be centrally controlled. This configuration optimizes space and simplifies wiring and communication.
SMC also provides hybrid vacuum units integrating valves and vacuum generation into a single compact module. These systems support centralized control through industrial communication protocols, including IO-Link, making them suitable for advanced automation environments.
Typical applications of vacuum generators
Vacuum generators are extremely versatile and are commonly used in:
- Handling systems with low to medium vacuum flow requirements
- Point-to-point gripping applications
- Decentralized vacuum systems without a central vacuum pump
Advantages of vacuum generators compared to other vacuum systems
Compared to other vacuum systems, generators offer several benefits:
- Maintenance-free operation: No moving or rotating parts
- Flexible installation: Can be installed directly at the point of use
- Fast vacuum generation: Rapid response time
- Compact and lightweight design: Ideal for decentralized systems
- No heat generation
- Integrated energy-saving functions : Optimized compressed air consumption
- Built-in monitoring and control options
These features make vacuum generators particularly suitable for modern automated machinery.
How to select the right vacuum generator?
Selecting the appropriate vacuum generator requires careful evaluation of the application parameters:
1. Nozzle and diffuser design
The nozzle diameter directly influences performance:
- A smaller nozzle diameter generates higher vacuum levels but lower suction flow.
- A larger nozzle diameter provides higher suction flow but lower maximum vacuum level.
The correct balance depends on whether the application prioritizes gripping force (vacuum level) or evacuation speed (flow rate).
2. Required suction flow and vacuum level
Define clearly:
- The required suction flow (air volume)
- The target vacuum level
- The desired response time
Pipe diameter and installation layout also influence how quickly the system reaches the target vacuum level.
3. Leakage considerations
Leaks caused by porous, uneven, or irregular workpieces can significantly affect performance.
- Use a vacuum generator with higher suction capacity
- Avoid excessively high vacuum levels
- Optimize suction cup selection
Proper sizing ensures stable operation and prevents unnecessary compressed air consumption.