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Deaeration Systems

Brix Meter Applicable in a range from 0 to 80 °Brix Most accurate technology for Brix measurement available Based on density and sound velocity measurement Accuracy: ± 0,03 °Brix (density based) and ± 0,07 °Brix (sound velocity based) Maintenance free and CIP capable

The presence of even low oxygen levels can increase microbiological activity and adversely affect taste, colour and shelf life of beverages and food products. Antioxidants such as vitamin C could be added to fruit juices and soft drinks to react with oxygen and increase product life time. However, such ingredients are expensive.

Although, vacuum deaeration systems (as offered by Centec) are used in large manufacturing plants to remove any kind of gases from products, many smaller beverage producers are not able to afford such invest. The price of a vacuum deaeration system can reach up to 100.000 EUR.

Centec’s highly innovative system developed by Centec. Through a Vortex nozzle, the Vortex deaeration unit injects a strip gas (CO2/N2) into the product. From the outlet of the system the product flows into a tank. There, the strip gas moves up “pushing” the oxygen molecules out of the fruit juice or the soft drink.

The Centec system delivers deaerated product continuously. The price for a medium sized Vortex deaeration unit (capacity: 200 hl/h) is about 10.000 EUR. These are great prices!

For manufacturing carbonated drinks, CO2 will be selected as strip gas leading to simultaneous carbonation during the deaeration process.

The oxygen content in the product can be reduced from appox. 11 ppm (saturated, ambient conditions) down to approx. 1 – 3 ppm. This will increase the shelf life of fruit juices and soft drinks.

Vortex Deaeration System.pdf

Centec Systems & Products

Based in Germany and with more than 40 years of Industrial and Scientific experience, Profile

Centec services customers in the food, beverage, pharmaceutical and chemical industries.

Centec Products are all about liquid and gas measurement and processing Technology and Measurement Instruments

Centec supplies both the High Precision Sensors and Complete Customized Ready to Use Process Units.

This is quite unique. This is Centec’s value proposition to all types of companies involved needing this type of equipment

(1) “Bolt in Place” Automated Process Skids

Company Flyer_Units.pdf

(2) High Precision Measurement Devices

Company Flyer_Sensors.pdf

Sensor Selection Information (non food)

Centec sensor reference pdf for use in Chemical industries (pages 1 – 6 Power plants (page 7) Pharmaceutical industries (page 8)

RHOTEC is used to determine the concentration of one media dissolved in a liquid based on density measurement.

SONATEC is used to determine the concentration of one media dissolved in a liquid based on sound velocity measurement.

COMBITEC combines the functionality of RHOTEC and SONATEC and has to be used for 3 component systems. In a three component system two different media are dissolved in a liquid. The concentration of both components is determined separately by density and sound velocity measurement.

OXYTRANS is used to measure the oxygen in liquids and gases. OXYTRANS TR is the in-line version; OXYTRANS M the portable one. OXYTRANS VI/VII was the previous model which has been replaced by OXYTRANS TR/M.

Centec Sensor Advantages.pdf

Centec sensors are applied in laboratory and process environments as “stand alone” devices or part of a process control system.

Centec instruments are used for the measurement of:

Oxygen in liquids and gases (OXYTRANS)

Dissolved carbon dioxide in liquids (CARBOTEC)

Concentration by density (RHOTEC)

Concentration by sound velocity (SONATEC)

Concentration density & sound velocity (COMBITEC)

Centec process units are applied for manufacturing in various industries. They are Bolt in Place fully automated, skid mounted systems designed to customer requirements.

Water purification (disinfection, softening, reverse osmosis, WFI distillation)

Water deaeration (by membranes, column, vacuum)

Gas injection (carbonation, nitrogenation)

Liquid blending and dosing


Product pasteurization


Pure steam generation

As a globally operating company, Centec is a reliable partner for customers all around the world. With more than 40 years of experience Centec serves:

Brewery & beverage industries

Dairies and food producers

Pharmaceutical manufacturers

Chemical factories

Power Plants

Steel Industry

Many industries need to make raw water (e.g. municipal water, well water, surface water) suitable for their applications. Usually, a water treatment regime consists of a combination of various purification steps such as:

In order for Centec to design and quote a water treatment regime, they need to receive an analysis of your raw water and they need to know the application. Please ask for the specialty Excel files that show the necessary data.

Have a look at the pdf documents below, to easily understand what technologies Centec is able to offer and what steps of water purification exist.

Overview pdf

Water Purification Technologies pdf

Centec Competence in Water Treatment.pdf

Water is an important ingredient for a wide range of products and processes. Thus, water treatment equipment is found in a large number of industries. Based on the raw water quality (water analysis) and the requirements for water after treatment, Centec select the most appropriate technologies for each client and their requirements – from the production of bottled water through to Purified Water (PW), Highly Purified Water (HPW), Water for Injection (WFI) and Pure Steam.

Centec offers all these technologies for the production of:

Process water – used as the base for manufacturing in food and beverage industries.

Purified Water (PW) – used for many applications in various industries (e.g. for autoclaves, laboratory testing, laser cutting). In pharmaceutical industries PW is used for manufacturing of nonsterile products.

Highly Purified Water (HPW) – used for manufacturing of medicines that require bacterial endotoxin control, except where WFI is required.

Water for Injection (WFI) – used for manufacturing of medicines for parenteral administration.

Pure Steam – used for sterilization purposes in various industries.

Multimedia / sand filtration

Softening / antiscalant dosing

Activated carbon filtration

UV disinfection

Demineralization (ion exchange, reverse osmosis)

Electro deionization

Ultrafiltration WFI distillation

Pure steam generation


De Alcohol Technology

For decades, the largest brewery groups in the world have trusted Centec technology. Centec equipment is used throughout the entire brewing process. One of our core competencies is the fully automated and aroma conserving dealcoholization of beer, wine and fermented products.

DeAlcoTec is a fully automated system for aroma conserving dealcoholization of beer, wine and fermented products.

Centec’s latest technology, tested in close cooperation with “Weihenstephan”, incorporates a very specific and highly efficient method for aroma recovery during the dealcoholization process.

Other features include e. g. in-line carbonation and recording of all relevant quality parameters of the product as well as the simultaneous rectification (concentration) of extracted alcohol up to 90 % ABV.

The specific benefit of Centec technology is extremely gentle processing at low temperature with a short retention time, thereby optimizing product defining aroma and flavour profiles. A residual alcohol content of 0,01 % ABV can be reached.

Sugar Production

During sugar manufacturing, sugar concentration can be measured and controlled with extremely high precision with our density sensor RHOTEC and our sound velocity sensor SONATEC.

The SONATEC is in operation at Grupo Pantaleon in Guatemala

Applications in sugar manufacturing.pdf

SONATEC Sugar Production pdf

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Measuring Concentrations in Solutions

Solid dissolved in a liquid or Liquid dissolved in another liquid

RHOTEC (density measurement) and SONATEC (sound velocity measurement) are used for a two component solution. (A two component system can be a solid dissolved in a liquid or a liquid dissolved in another liquid.)

These applications are common where a media such as sugar, salt, alcohol, etc. is dissolved in water. (Also most acids and caustics are aqueous – water based – systems.)

To determine the concentration of extract and alcohol, density and sound velocity are measured simultaneously. This is done by COMBITEC – a combination of RHOTEC and SONATEC (“two sensors in one”). (Density measurement allows calculating the concentration of alcohol while the concentration of extract is calculated based on sound velocity measurement.)

Also note Centec offer RHOTEC and SONATEC in an explosion proof version, so they can be used in ATEX (explosive atmosphere) environments.

Attached you find some reports describing common applications related to two and three component systems. As you see, they are found in different industries.

For applications in chemical industries it is extremely important to know the type of acid/caustic as well as the concentration / temperature range of the measurement. (The selection of the sensor material which is resistant against the acid/caustic. e.g. stainless steel, hastelloy, monel, incoloy, tantalum)

For each two component system there exists a certain relationship between density (sound velocity) and concentration which can be described by a system specific polynomial formula. With this formula it is possible to calculate the concentration based on density (sound velocity) measurement.

This is the how the Centec sensors RHOTEC (SONATEC) work.

A three component system is a system that includes three media. Many of them are also aqueous (water based) systems.

Oxygen Measurement

Optical oxygen measurement is state of the art and provided by Centec and several of our competitors. However, many sensor manufacturers offer Clark electrodes to determine the oxygen content in the product. Therefore, you should know the principle of both technologies and the advantages of the optical method.

Optical method

Optical oxygen sensors contain a small glass component (“optical window”) installed in the measuring head. On the surface of the optical window there is thin film of fluorescent molecules. A polymer optical fiber transmits excitation light (blue-green-light) from the light source to the fluorescent molecules. When the molecules absorb this blue-green-light they are promoted to a higher energy state. After a certain time they convert back into a lower energy state during which a detectable red light is emitted. The same polymer optical fiber transmits this red light to the measurement device.

If oxygen is present the energy is transferred from the excited fluorescent molecules to the oxygen. Thus, the detected red light decreases according to the oxygen content. Centec offers an in-line oxygen sensor (OXYTRANS TR) and a portable device (OXYTRANS M). Both of them use the optical method.

Clark electrode

Clark sensors contain two electrodes which are linked by a potassium chloride solution (KCl) serving as electrolyte. One electrode consists of platinum (Pt); the other one consists of silver (Ag). When a small constant voltage is applied across the two electrodes the Pt becomes negative (> cathode) and the Ag becomes positive (> anode). The electrolyte and the product are separated by a thin membrane which is permeable to oxygen. The partial pressure difference of oxygen between both sides of the membrane is the force “pushing” the oxygen from the product through the membrane into the electrolyte.

At the cathode, electrons are “consumed” by the reaction with H2O and O2 which leads to OH-. At the anode, silver reacts with Cl- from the electrolyte to produce AgCl and free electrons. The silver chloride (AgCl) deposits on the surface of the silver electrode. The OH- produced at the cathode combines with the K+ from the electrolyte, so the electrolyte changes from KCl to KOH. The free electrons generated at the anode flow through the circuit to the cathode resulting in a current that is proportional to the concentration of oxygen (see attachment).

Disadvantages of the Clark method

Due to the consumption of Cl-, the electrolyte needs to be replaced frequently

The membrane is sensitive to pressure shocks and fouling, so its life time can be short

Removing the AgCl deposits from the anode is a time consuming procedure

Frequent calibration results in high upkeep and labor costs

Oxygen is consumed from the product during the measurement

There has to be a constant product flow to avoid inaccurate readings

After disconnecting and connecting again, the sensor can need hours for polarizing

Clark sensors are less accurate compared to optical oxygen sensors

Clark electrode.pdf

Centec OXYTRANS-E.pdf

CO2 Measurement

It is mainly in food and beverage manufacturing where CO2 needs to me controlled.

Centec offers two types of CARBOTEC sensors for CO2 measurement:

(1) Pressure/temperature method


The concentration of CO2 dissolved in a liquid is determined in a closed volume (sensor head) by measuring the pressure and temperature when a state of equilibrium between the liquid and the gas in the sensor head exits. CARBOTEC calculates the content of CO2 in the liquid by applying a product CO2 specific formula.

(2) Optical method


CO2 is measured selectively and uninfluenced by other gases based on Attenuated Total Reflection (ATR). While passing a crystal, a beam of infrared light is reflected at the surface which is in contact to the carbonated liquid. Each time the beam is reflected, the CO2 molecules absorb some of the light. By intensity measurement of the infrared light, CARBOTEC NIR precisely calculates the CO2 concentration.

Without any moving parts in the sensor, CARBOTEC NIR is basically free of maintenance. It allows determining “true” CO2 content even when there is a mixture of gases in the liquid!

Centec Summary:- cold block engineering & automation, water treatment, water deaeration, wort aeration, yeast pitching, carbonation, carboblending, nitrogenation, liquid blending, flash pasteurization, dealcoholization, cleaning-in-place, oxygen measurement, carbon dioxide measurement, determination of concentrations by measuring density and sound velocity.

CARBOTEC Food and Beverage.pdf

CO2 content has a strong influence on the quality and taste of alcoholic and nonalcoholic beverages. Therefore, CARBOTEC is a crucial instrument for manufacturing beers, sparkling wines, soft drinks, mineral waters and all other types of carbonated products.

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Mass Flow meters versus RHOTEC

Centec is oftwn asked if they provides mass flow meters. The answer is “no”. Read on.

A mass flow meter can be used to determine density. However, customers requiring high accuracy may be interested in Centec’s density sensor RHOTEC.

So keep in mind, RHOTEC could be an alternative to a mass flow meter.

And RHOTEC allows determining the concentration of a media dissolved in a liquid based on the relationship between density and concentration.

RHOTEC (in-line version) RHOTEC – E pdf


There is a nice description of the working principle of a mass flow meter in the internet

RHOTEC is about ten times more accurate than a mass flow meter. This is due to the very high frequency we apply for density measurement.