With the increasing level of automation in beer brewing, the use of sanitary electro flow meters has become more widespread. From measuring brewing water for milling, lautering water, wort filtration, cooled wort, bright beer, to finished beer transfer, sanitary electromagnetic flow meters are used throughout the process. To ensure measurement accuracy during operation, it is important to understand and pay attention to the following considerations.
Sanitary electro flow meters used in the beer production process have their own specific requirements. For example, they must prevent bacterial growth, allow frequent cleaning, and withstand corrosive alkaline water and hydrogen peroxide disinfectants under high-temperature conditions. The detailed requirements include:
- The measuring circuit of the sensor must be simple, with no obstructions or components that can trap media.
- All wetted parts and materials must comply with food-grade hygiene standards, such as FDA (U.S. Food and Drug Administration) and EHEDG (European Hygienic Engineering & Design Group) requirements.
- Wetted components must withstand sudden temperature changes and corrosion during steam, alkaline solution, and hydrogen peroxide cleaning.
- When used in the filling process, the flow meter must provide fast response time and high measurement accuracy.
- The instrument must be able to operate reliably in low-temperature environments (around 2°C) and high-humidity conditions.
Factors Affecting the Accurate Operation of Sanitary Electro Flow Meters
(1) Build-up on the sensor’s inner wall.
During long-term operation, scale and sludge deposits tend to accumulate inside the sanitary electro flow meters. These deposits may slightly reduce the effective cross-section of the pipe, but the major impact lies in altering the electrical resistance between the two electrodes.
If the conductivity of the deposit layer is significantly higher than that of the fluid, the electrode circuit will be short-circuited, resulting in no flow signal output.
If the deposit layer is insulating, the electrode circuit will be open, causing the electrodes to lose electrical continuity and preventing the output of a valid flow signal.
Measures:
Since most flow meters used in beer brewing are not equipped with cleaning pipelines, the sensor should be removed periodically to clean the electrodes. If conditions permit, a flushing line can be installed to clean the electrodes regularly.
When process conditions allow, choose a smaller meter size to increase flow velocity, enhance scouring effects, and reduce buildup.
(2) The fluid must completely fill the pipe during normal operation, and the presence of air bubbles must be avoided.
If the fluid does not fully fill the pipe, the effective cross-section will differ from the pipe’s actual inner diameter, resulting in volumetric flow calculation errors.
If the measured liquid contains small, evenly distributed microbubbles, the meter can usually operate normally. However:
As bubble size increases, output fluctuations occur.
If a bubble becomes large enough to fully cover the electrode surface, the electrode circuit will momentarily open as the bubble passes over it, causing significant output signal spikes.
Measures:
Strictly follow installation requirements to ensure proper mounting and to prevent air entrainment.
(3) During normal operation, sanitary electro flow meters must be protected from various external parasitic voltages and interference generated by the device itself.
Electromagnetic flow meters operate based on the principle of electromagnetic induction. Flow signals are extremely small—only a few millivolts at full scale and just tens of microvolts near the lower range—making them highly susceptible to electromagnetic interference from nearby motors, transformers, and other electrical equipment.
Common sources of interference include:
Stray currents generated by nearby electrical equipment flowing through metal pipelines (e.g., welding operations on the pipeline), which then affect the meter through the pipe and the process fluid.
The sanitary electro flow meter sharing a common ground with motors or electrical devices, or being grounded through water supply/drainage pipes, allowing leakage currents from power equipment to enter the flow meter via the common ground.
Electromagnetic fields generated by nearby electrical devices interfering with the signal cables and electronic circuits.
Measures:
Install the flow meter strictly according to the specified installation and grounding requirements.
The sanitary electro flow meter uses a new hygienic-grade lining material and an improved lining manufacturing process. The stainless-steel housing and stainless-steel fittings are connected using clamp (tri-clamp) couplings, allowing for quick disassembly and cleaning in sanitary applications. This design minimizes contamination risks and effectively prevents residual product from accumulating inside the measuring tube.
It is widely used in the production processes of foods such as mineral water, soy sauce, jams, beer, juice, yellow rice wine, and milk, as well as in sanitary and chemical industries.
