Diaphragm compressors, with their advantages of zero leakage and high cleanliness, are widely used in the chemical, pharmaceutical, and nuclear power industries. Their core design differences primarily lie in their configuration, which is detailed below in four categories:
1. Single-Stage, Single-Acting
This type has the simplest structure, compressing gas through the reciprocating motion of a single diaphragm. One side of the diaphragm contacts the medium, while the other side is driven by hydraulic oil. The compression ratio is typically 1:3 to 1:8 (data source: Compressor Engineering Handbook).
Features:
- Low cost and easy maintenance;
- Low output pressure, suitable for laboratories or small air supply systems;
- Typical applications: Medical oxygen compression and air supply for small pneumatic tools.
2. Single-Stage, Double-Acting
The diaphragm alternates between two sides to compress gas, with hydraulic oil driving the center. Compression efficiency is increased by over 30% (refer to experimental data from Fluid Machinery, 2021).
Features:
- Smoother continuous output with minimal vibration;
- Suitable for medium-pressure applications (0.5-10 MPa);
- Requires a two-way valve block, resulting in a slightly more complex structure.
3. Multi-stage Series
High-pressure output is achieved by connecting two or three compression units in series, with coolers between stages. For example, a three-stage series can compress natural gas to 25 MPa (example cited from API 618).
Features:
- The compression ratio of each stage is controlled within 3 to avoid diaphragm overload;
- High energy consumption, but suitable for high-pressure applications such as liquefied gas storage;
- Typical industry: hydrogen fueling stations for hydrogen vehicles.
4. Opposed Balanced
Two diaphragm sets are symmetrically arranged, with a 180° phase shift, to offset inertial forces. Vibration amplitude is reduced by 70% (data source: Patent CN110685952A).
Features:
- Suitable for high flow rates (>500 m³/h);
- Compact structure but requires high processing precision;
- Commonly used in the nuclear power industry for inert gas processing.
Extended Analysis:
Model selection requires a comprehensive consideration of pressure requirements (e.g., single-stage <10 MPa), media characteristics (corrosive gases require coating), and space constraints (opposed-type diaphragms take up less space). Future trends will focus on intelligent monitoring (e.g., diaphragm crack warning) and the use of composite materials (e.g., graphene-reinforced diaphragms).
