Nitrogen cleaning process
Raising safety standards and quality
Industrial gases play an important role in chemical industries and their key applications include cleaning, maintenance, safety measures and environmental protection; Purging involves adding a neutral gas (usually nitrogen) to displace unwanted gases.
In nitrogen cleaning, production systems using nitrogen gas are widely used to remove undesirable and dangerous gaseous and non-gaseous impurities. This process is essential for daily operations in a wide range of industries such as chemical, pharmaceutical, oil and gas industries. These industries are usually associated with environments prone to unwanted moisture, hazardous gas, and oxygen. Engineers can effectively remove these impurities with a nitrogen purge process, creating a stable environment ideal for safe industrial operations.
Why is nitrogen used for cleaning?
Nitrogen has wide applications in the industry and depending on the application, it can be used for many tasks and purposes. Nitrogen makes up approximately 78% of the atmosphere and makes it readily available. In addition, due to its neutral and non-flammable properties, this gas is ideal for displacing combustible gaseous impurities that create an unstable and potentially flammable atmosphere. In other words, nitrogen can minimize moisture, oxygen and other contaminants that pose a risk in industrial processes.
Be sure to read: methods of extracting gases in the air
Four nitrogen cleaning systems
Various factors influence the selection of a nitrogen purge system in various industrial applications, including the nature of the industrial equipment (eg, shape and type) and operator requirements and preferences.
The four essential nitrogen purge systems incorporated in industrial applications are:
- Dilute cleaning
- clearing displacement
- Vacuum pressure holding method
- Liquid transfer under pressure
1) Dilute cleaning
Dilution cleanup helps remove undesirable gaseous impurities from complex industrial systems such as reactors, columns, and furnaces. This nitrogen cleaning system includes a mixture of nitrogen gas with other gaseous pollutants, which are removed through the outlet point, which is as far away from the gas inlet as possible. Then the operators remove this resulting mixture from the industrial system. The final result of this nitrogen cleaning system includes an industrial system that is ineffective and risk-free.
2) Displacement cleanup
Displacement cleaning is ideal for simpler industrial systems and sections, such as pipelines. This simple technique involves a cleaning component called a pig, which moves through the industrial system to remove unwanted materials. With the help of pressurized nitrogen, operators guide the Pig through the pipe channels and the contents such as gaseous impurities and particles are freed. Displacement purging significantly minimizes the need to mix nitrogen gas with other industrial system components. However, the volume of nitrogen required by the purge system for efficient purge depends on the pipe capacity.
3) Pressure-maintaining vacuum method
This nitrogen cleaning system involves flushing an industrial system using a pressurized nitrogen tank. This cleaning system provides the possibility of combining nitrogen under pressure with other contents and finally diluting and exiting the resulting mixture from the valve. Operators repeat this process until the system or industrial equipment reaches an acceptable standard. Unlike displacement purging, the volume of nitrogen required for this method depends on the number of times the operator repeats the process.
4) Transfer of liquid under pressure
Operators typically choose liquid pressure transfer cleaning systems due to space limitations or the presence of materials that negatively affect pump efficiency. In this system, nitrogen gas drives fluid movement by pressurizing the headspace of a vessel, resulting in undesirable fluid removal without adequate pressure pumps. In addition, this cleaning method significantly limits the possibility of oxidation that is usually associated with liquid transfer between two tanks.
While the most common cleaning gases include nitrogen and carbon dioxide, other inert gases such as argon or helium may be used; Because these gases (nitrogen and carbon dioxide) may undergo a chemical reaction when exposed to fine dust from certain light metals.
Be sure to read: Nitrogen applications in gas and liquid form