Vacuum Deaeration Theory and Characteristics
Vacuum deaeration is a device used to reduce the amount of dissolved oxygen and other gases such as carbon dioxide from a liquid medium. The process involves lowering the absolute pressure surrounding the liquid, below the vapor pressure of the gas in the liquid, creating a partial vacuum, allowing the gas molecules to be released. Vacuum deaeration can occur anaerobically, requiring no external oxidant, via a process known as Knudsen expansion. It can also occur aerobically, which requires contact with an oxidizing agent, such as oxygen, to transform the dissolved gas into a different form, usually carbon dioxide or gaseous nitrogen. The benefits of vacuum deaeration are that it is relatively inexpensive and energy efficient, producing a consistent and reliable deaerated liquid.
The theory behind vacuum deaeration is that the lower pressure of the surrounding atmosphere causes a decrease in the vapor pressure of the gas in the liquid, allowing it to escape from solution. This decrease in pressure occurs until the forces of attraction between the gases and the liquid become greater than the force of atmosphere. At this point the gas molecules escape from the liquid and move to the atmosphere, allowing for a reduction in dissolved gases and forming a deaerated liquid. The rate of deaeration is determined by several factors, such as the size of the gas molecules, the pressure and the solubility of the gas.
Practically speaking, vacuum deaeration works by using a combination of vacuum and heat to reduce the amount of dissolved gases in a liquid medium. An expanded liquid medium is placed inside of a vacuum chamber. A vacuum is then established inside of the chamber and heat is applied, usually by a heat exchanger, to partially vaporize the liquid medium. The vaporized medium then expands, which decreases the pressure in the chamber and causes the dissolved gases to break free from the liquid molecules. This in turn allows the gases to escape and leave the liquid medium in a deaerated state.
Vacuum deaeration is an efficient way to remove dissolved gases from liquid media, with minimal energy expenditure, and can be used to reduce the amount of oxygen and other dissolved gases, such as carbon dioxide, in a variety of liquids and applications. Vacuum Deaeration has several advantageous characteristics, including:
• It is relatively inexpensive, which makes it a cost-effective option for a variety of liquid deaeration applications.
• It is fast and efficient, with a high-vacuum environment allowing for a more rapid process.
• It produces a consistent, reliable result, with a high degree of repeatability and uniformity.
• It is relatively safe and non-corrosive, reducing potential health and environmental risks.
• It can reduce and control the level of dissolved gases, such as oxygen and carbon dioxide, in a wide variety of liquids, including beverages, dairy products, syrups and other concentrated solutions.
Overall, vacuum deaeration is an effective, energy-efficient and cost-effective method of reducing dissolved gases and producing a consistently deaerated liquid. It is suitable for a variety of applications and can be used in food, beverage and water processing industries to reduce or eliminate the presence of oxygen and other dissolved gases.
