1. Membrane separation principle
Typically, all gases can permeate through a polymer membrane. The process begins with gas molecules being adsorbed and dissolved on the high-pressure side of the membrane. They then diffuse across the membrane due to the concentration gradient and are finally released from the low-pressure side. As a result, small molecules and highly polar molecules (such as water vapor, oxygen, and carbon dioxide) pass through more quickly and accumulate on the permeation side of the membrane. Conversely, large molecules and less polar molecules (such as nitrogen and argon) pass more slowly and are retained on the retention side of the membrane, accumulating there to achieve the separation of mixed gases. Membrane separation utilizes the different permeation rates of various gases across the polymer membrane. The driving force for this separation is the partial pressure difference of the gases on either side of the membrane. Therefore, membrane gas separation does not involve phase changes or require regeneration, offering advantages such as simple equii
A membrane separator (component) is a hollow fiber separation membrane container with thousands of hollow fibers in one shell. Its structure is similar to that of a tubular heat exchanger, which can provide the maximum separation membrane surface area in the minimum space, so the membrane separation system has the advantages of small footprint, light weight and high separation efficiency.
2、 The process flow of membrane separation nitrogen generator:
The schematic diagram of the process of membrane separation nitrogen generator is as follows:
Overview of production process:
The air is compressed by the compressor, and after cooling in the air storage tank, it enters the first-level precision filter at a pressure of 1.25MPa to remove liquid and oil mist in the compressed air. It is then filtered by the second-level precision filter and the third-level precision filter to remove particles and oil mist, which can reduce the oil content in the compressed air to below 0.01ppm, and can filter out all solid particles with a diameter greater than 0.01μm; and is heated by a stainless steel heater, and enters the membrane separation system for separation at a pressure of not less than 1.2MPa and an air temperature of not less than 30°C. Compressed air can be separated by membrane to obtain nitrogen with a pressure lower than the intake pressure, and the purity of nitrogen reaches 95%-99.9%.
