The historical way to regulate dosing systems in food and beverage is with
pumps. While these get the job done, they are not very accurate. A higher accuracy alternative involves using a flow meter to continually measure output flow and compare it against a setpoint. This feedback loop allows for increased control accuracy, linearity, and repeatability in large scale production environments. Here we discuss three common flow technologies used to regulate the variety of liquids required for dosing in food and beverage processes: electromagnetic, ultrasonic, laminar, and Coriolis.
Electromagnetic flow meters can provide cost-effective solutions and are also compatible with clean‑in‑place (CIP) and sterilize‑in‑place (SIP) processes. However, these flow meters rely on the conductive properties of water and can give unreliable readings if you are flowing de‑ionized water or liquids containing bubbles.
Ultrasonic flow meters using the Doppler Effect require particulate material or bubbles to reflect the signal, rendering them ineffective with pure, smooth liquids. Conversely, ultrasonic devices using transit time to measure flow can
only work with pure fluids. A combination of the two can be employed, but this has additional cost implications as well as issues with reduced accuracy in low flow conditions. A perk of ultrasonic flow meters is their ability to measure non‑invasively, although they also tend to be sensitive to process vibrations.
Laminar mass flow meters and controllers can be used for fast, accurate measurement and control of fluids with known compositions. Mass flow controllers have fast proportional control valves and quick response times, and some controllers are available with a
totalizer function to make precision dosing possible for batch processing. Laminar mass flow instruments can only be used when the process liquid is unchanging, and its fluid properties are known.
Coriolis flow meters and controllers offer a solution to some of these limitations.
Coriolis technology enables accurate measurement and control of mass flow even when the fluid composition of dosing mixtures is changing. More compact‑type Coriolis devices are ideal for low‑flows and also provide density readings. Additionally, dosing solutions with Coriolis can be made with CIP/SIP compatibility. And although they are often associated with a higher initial cost, long time cost of ownership for Coriolis instruments is reduced since no annual recalibration is typically required.
While some large scale food production processes require high flow rate Coriolis instruments, many dosing applications can benefit from the precise, low‑flow measurement and control offered by the
CODA™-Series Coriolis mass flow meters and controllers. With flow rates ranging between 40 g/h to 300 kg/h, CODA devices are available for gases and liquids.
Contact Alicat® to learn more about how Coriolis can maximize your process for dosing food, beverages, and in other industries.