TECHNICAL RESOURCES

 

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Helium

Helium is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions.  It is the second lightest element and is the second most abundant element in the observable universe

Helium Properties :

1. Molecular weight  : 4.0026 g/mol,Melting point (under 26 atm) : -272.2 °C

   Liquid phase

1. Liquid density (1.013 bar at boiling point) : 124.96 kg/m3

2. Liquid/gas equivalent (1.013 bar and 15 °C (59 °F)) : 748 vol/vol

3. Boilingpoint (1.013 bar) : -269 °C

4. Latent heat of vaporization (1.013 bar at boiling point) : 20.3 kJ/kg

   Critical point

1. Critical temperature  : -268 °C

2. Critical pressure  : 2.275 bar

3. Critical density  : 69.64 kg/m3

   Gaseous phase

1. Gas density (1.013 bar at boiling point) : 16.891 kg/m3

2. Gas density (1.013 bar and 15 °C (59 °F)) : 0.169 kg/m3

3. Compressibility Factor (Z) (1.013 bar and 15 °C (59 °F)) : 1.0005

4. Specific gravity (air = 1) (1.013 bar and 21 °C (70 °F)) : 0.138

5. Specific volume (1.013 bar and 21 °C (70 °F)) : 6.037 m3/kg

6. Heat capacity at constant pressure (Cp) (1 bar and 25 °C (77 °F)) : 0.02 kJ/(mol.K)

7. Heat capacity at constant volume (Cv) (1 bar and 25 °C (77 °F)) : 0.012 kJ/(mol.K)

8. Ratio of specific heats (Gamma:Cp/Cv) (1 bar and 25 °C (77 °F)) : 1.664

9. Viscosity (1.013 bar and 0 °C (32 °F)) : 0.0001863 Poise

10. Thermal conductivity (1.013 bar and 0 °C (32 °F)) : 142.64 mW/(m.K)

Application :

Helium is used in cryogenics, particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners.

Helium's other industrial uses—as a pressurizing and purge gas for Fine Leak Testing , and as a protective atmosphere for arc welding and in processes such as growing crystals to make silicon wafers.

Helium has unique properties that make it valuable for use in a wide range of applications. Its properties make fine leak detection possible, which has led to the adoption of helium usage in mass spectrometry helium leak detection technology, enabling many companies such as OEMs, tier one automotive part manufacturers, etc. to produce quality product while remaining competitive.

Why Use Helium?

• -Helium is present in the atmosphere at around five parts per million which results in lower instrument background and therefore better test sensitivity.

• -It's inert. The only danger when using helium is simple asphyxiation but only when used without adequate ventilation.

• -It's light. Helium will dissipate quickly allowing fast cleanups of the mass spec and ultimately shorter test times.

Who Uses Helium Leak Detectors?

Helium leak detection is one of the most widely used methods of nondestructive testing in use today. Current applications span a diverse field of products and industry. Bio-tech companies use helium leak detectors to test implantable medical devices such as pacemakers to insure

that the outer packages are protected from bodily fluids and to protect patients from possible contamination from leaking batteries and other materials. Automobile manufacturers use helium leak detection technology to test items such as air bag initiators, radiators and air conditioning units. Semiconductor fab’s widely employ leak detectors to leak test process

equipment

Why Helium Recovery?

 

Helium recovery and recycling make sense. With the ever increasing costs of helium, the economics of installing recycle systems become increasingly attractive. Many factors need to be taken into account in deciding the most effective helium recycle solution for a given situation. The economics of recycling improve with increased volume use. Helium users need to be aware that using a helium recycle unit can not only lower costs and protect an important resource,

but can also open the door to other applications and opportunities.