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%.
