The manufacturing of equipment for ozone and oxygen generation is globally dominated by just a few suppliers. Gardner Denver has been a part of these processes for decades and has adapted its compressors and systems to comply with the special aspects of them. Very few specialists are familiar with these applications.
The air around us consists of 21% oxygen (O2) and 78% nitrogen (N2). The rest is a mixture of argon (Ar), carbon dioxide (CO2), hydrogen (H2) and other trace gases. While an oxygen molecule typically consists of two atoms, ozone (O3) is made up of three oxygen atoms. In nature, ozone only occurs in small quantities, although it is relatively common.
A large amount of energy is required to bring the three atoms together. Once created, ozone tends to decompose to oxygen while giving off large amounts of energy. This decomposition is carried out without any residues. Due to this, ozone cannot be stored, but must instead be produced directly for use.
When producing ozone, a high level of alternating high voltage is connected to two special electrodes, separated from each other by a gap. A stream of oxygen or air is routed through this gap and silent, electrical discharging occurs in the gas stream, resulting in the formation of ozone.
Ozone is used in a wide variety of industrial applications. Its high oxidation kills germs and is, therefore, often used for disinfection. In water-treatment plants, unprocessed water is treated with ozone to obtain clean, germ-free drinking water. This type of disinfection is also required for mineral water. Other applications include sanitization of swimming pool water, disinfection in medicine, air purification and the treatment of foodstuffs.
Another important application is ozone bleaching in the cellulose industry (pulp and paper). Compared to chlorine bleaching, it is an extremely environmentally friendly process, as it leaves behind no toxic substances of any kind (e.g. chlorinated hydrocarbons or toxic dioxins). One of the pioneers in this application is Lenzing. In a multi-stage bleaching process, first oxygen, then ozone and finally peroxide (also called final bleaching) is used.
Probably the newest application is the use of ozone when manufacturing viscous fibers. This increases the strength and elasticity of the fibers.
Because of its high oxidation potential, ozone has a strong tendency to cause corrosion. Of course, this also places extremely demanding requirements on the materials used in its production. The most frequently used compressors for ozone and oxygen compression are the models NASH 2BG1151 and NASH 2BG1150. These models reliably supply the required compression pressure of 13 bar abs. In exceptional cases, compression pressures up to 17 bar abs can be attained. Some of the user-specific design features of these compressors are the mechanical shaft seal, shaft, material, freedom from oil, etc.
In addition, compressors of the NASH 2BE1 series are used as pre-compressors for ozone or oxygen. In water-treatment plants, these compressors are frequently used for ozone compression.
The compressor systems are designed and built in coordination with our customers, using our combined experience. The design, durability and transfer points are especially important. Ozone decomposition must always be avoided, as this releases large amounts of energy and can lead to the destruction of the compressors. Therefore, temperature control and the monitoring of the entire process, for example, are required. In addition, our customers install a pH control system to prevent the generator’s materials from being attacked. The system's design must provide corresponding safety functions, i.e. it must be possible to reliably compress the specified ozone quantity in every operating situation. The quantity to be created is documented up to the third decimal place via the electric current consumption. As a result, the compressors are designed to meet or exceed the specifications with no negative tolerance.
Our expertise in this application ensures a high level of success.