The Carbonating Process

Everybody loves a refreshing sparkling drink during the summer heat. CO2 does not only bring the bracing sparkling effect into your drink but even helps to conserve the beverage. A chemical reaction of CO2 and water forms carbonic acid which has an antibacterial effect. All well known soft drinks come with the right fizz.

The beverages are treated with a carbonating process just before the final bottling or canning. Carbonating systems mainly consist of a booster pump, a CO2 saturator, a carbonating tank and an optional CO2 analyser to check the carbon acid content of the final product.

With the aid of a booster pump the beverage mixture is conveyed to the saturator which works according to the Venturi principle. An optimising control keeps the flow velocity through the saturator within a constant working range. This generates a partial vacuum at the smallest cross section of the saturation which causes a reduction of the pressure level. This suction effect then mixes the CO2 with the beverage liquid. The short-time increase of the flow velocity guarantees a fine distribution of the gas and homogenous mixing.

The process essentially depends on the tank pressure which has to be set slightly higher then the saturating pressure of a specific product. Right after that, the drink is ready to be bottled automatically to preserve its texture.

CO2 saturator in a carbonating stage of a bottling line

Why the need to monitor CO2 in a beverage plant?

Carbonating processes use most of the CO2 in the beverage industry. But beside that the gas also occurs during fermentation or it is used for refrigeration – so CO2 is omnipresent in such facilities.

High concentrations of CO2 in closed areas where workers attend to their jobs can become a lethal risk. Extensive CO2 levels can lead to bad headaches, drowsiness, unconsciousness and even sudden death. A CO2 level above 5000ppm is considered as alarming. The gas can neither be recognised by its odour nor by its visual appearance. Soft-drink factories or breweries therefore require an accurate CO2 control and alarm system to maintain their high standard of operational safety.

To assure hygienic conditions and to reduce the risks of CO2 incidents, bottling lines which fill carbonated drinks are often operated in separated areas of a factory. There is a controlled loss of CO2 during the bottling or canning process of sparkling drinks which is minimal, but the amount adds up considering that industrial lines are able to fill up to 30.000 bottles an hour. With each filling a tiny amount of CO2 gets exposed to the surrounding atmosphere.

Factories require big amounts of CO2 which is delivered and stored in gas cylinders. During transport or storage there is always the risk of a thin crack occurring and that gas escapes unnoticed. Drinks which are not meant to be carbonized such as beer or wine also emit CO2 during the fermentation process. The gas needs to be release controlled. Also here leakage can be a danger and CO2 sensors help to keep control of the atmosphere.

This small insight shows how beverage manufacturers depend on reliable CO2 monitoring systems!

Candice – Sales Support