Alfa Laval Flow Instruments
Alfa Laval Flow Transmitter
Alfa Laval flow transmitters are electromagnetic precision meters used to measure the volumetric flow rate of electrically conductive liquids. Hygienically designed, these are excellent choices for use in the dairy, food and biopharm industries.
Related Industries:
Food and beverage, Home and Personal care
High precision flow measurement
Alfa Laval flow transmitters are bi-directional electromagnetic precision meters used to provide accurate process flow measurement of electrically conductive liquids. They are especially suitable for installations where solid particles are present in the liquid. With no moving parts and no pressure drop, these flow transmitters provide high accuracy, excellent long-term stability and performance.
Durable hygienic flow transmitter design
Authorized to carry the 3-A symbol, Alfa Laval flow transmitters feature a sturdy waterproof design. Other hygienic features, such as the (PFA) Teflon coating on the interior of the metering tube and completely embedded, hermetically sealed electronics, contribute to long service life of these magnetic inductive flow transmitters.
Compact and easy to install
Designed for tight mounting positions, standard Alfa Laval flow transmitters are delivered with pre-set factory pulse output signals to facilitate installation. The standard output is a pulse signal (0 to 1000 Hz) with a resolution of either 0.01 or 0.1 liter/pulse. Analogue 4-20 mA output and advanced display-enabling features are available as options.
Terminals for electrical connection are marked with both number and function; all cables can be threaded through three PG-11 cable glands.
Operating principle
The Alfa Laval flow transmitter is a magnetic inductive flow transmitter that operates according to Faraday’s law of electromagnetic induction. It consists of a metering pipe and two magnetic coils. When a current is applied to the coils, a magnetic field is produced at right angles to the metering pipe.
The liquid to be measured flows through the metering pipe perpendicular to the magnetic field. It acts as a conductor and induces an electrical voltage. Two sensing electrodes mounted in the metering pipe measure this voltage. The voltage is proportional to the average flow velocity and therefore accurately reflects the volume of the liquid flowing through the tube.
Constructed to handle multiple liquids
The Alfa Laval flow transmitter uses a square measurement chamber. The shape of the measurement chamber significantly reduces the influence of viscosity, type of liquid, and flow profiles. It also eliminates any need for recalibration when changing product, for instance, from milk to water.
The microprocessor in the transmitter controls the current generator to maintain a constant magnetic field. The voltage across the electrodes is amplified and converted to a digital value from which the microprocessor calculates the volume of the liquid flowing through the tube.
Application
The Alfa Laval Flow Transmitter is designed to fulfill the demands of hygienic and pharmaceutical production. Amongst others it is suitable for flow measurements in food, beverage, dairy and biopharm industries. The main features are;
- Constructed to be independent of variations in flow profile, the presence of solids and even changes in product viscosity.
- Suitable for hygienic applications; meets 3-A standards
- No internal pressure drop
- Robust and compact design, temperature tolerant up to 115°C
- Easy to mount even in difficult applications
- Optimized for high accuracy and linearity
- Pre set-up from from factory, ready for installation
- Bidirectional (can measure in booth flow directions)
- No moving parts; no maintenance
Electrical data
The Alfa Laval Flow Transmitter is pre-setup from factory ready for installation and has as standard integrated automatic zero point adjustment. As an option The Alfa Laval Flow Transmitter can be delivered with display giving access to advanced features such as integrated temperature compensation through external pt100 sensor, PI regulator and for low flows a linearization function further optimizing the accuracy at low flows.
Standard Range
The Alfa Laval Flow Transmitter is an electromagnetic precision meter for volumetric measurement of liquids that are electrically conductive. The transmitter can be used in applications where a hygienic design is required and the rugged construction of the transmitter makes it suitable for installations where solid particles are present in the liquid. The standard version is delivered pre-setup making installation quick and easy. The output signal is as standard a pulse-signal (0 to 1000 Hz) with a resolution of either 0,01 or 0,1 ltr/pulse. As an option the Flow Transmitter can be delivered with analogue 4-20 mA output or profibus DP. A display can be attached enabling advanced features, such as scaling and changing of resolution. The metering tube is coated with PFA on the inside and is fitted with clamp connections. The sensitive electronic is completely embedded and consequently hermetically sealed. The flow transmitter is water proof with protection class IP 67. The terminals for electrical connection are marked with both number and function and cable access is done through 3 PG-11 cable glands.
Working principle
The Alfa Laval Flow Transmitter consists of a metering pipe and two magnetic coils. When a current is applied to the coils a magnetic field is produced at right angles to the metering pipe. With a conductive liquid flowing through the metering pipe an electrical voltage is induced and measured by two electrodes mounted in the metering pipe. This voltage is proportional to the average velocity of flow and therefore to the volume flowing. The Alfa Laval Flow Transmitter utilizes a square measurement chamber. The shape of the measurement chamber significantly reduces the influence of viscosity, type of liquid, and flow profiles and eliminates any need for recalibration when changing product for instance from milk to water. The microprocessor in the transmitter controls the current generator keeping the magnetic field constant. The voltage across the electrodes is amplified and converted to a digital value from which the microprocessor calculates the liquid flow.
Alfa Laval Flow Meter
Flow meters provide accurate measurement of feed, permeate, retentate and diawater flows in membrane filtration modules and plants for a wide range of hygienic industries.
Related Industries:
Food and beverage, Home and Personal care
Accurate flow measurement
Alfa Laval flow meters are hygienic flow measuring instruments that enable accurate detection of liquid levels in membrane filtration modules and plants. Easy-to-read scales located in front of the tubes provide excellent visibility of the indicating floats.
Hygienic flow meter design
Alfa Laval flow meters feature a precision-machined tapered glass metering tube with a smooth surface. All materials comply with US Food and Drug Administration regulations, and all product-wetted parts are made of AISI 316L stainless steel and polysulphone. The flow meters are designed to withstand process temperatures between 0 and +100°C (+32 and 212°F).
Flow meter range
Alfa Laval flow meters are available in four nominal diameters, covering flow ranges from 60 l/h up to 20,000 l/h (16 – 5,283 U.S. gal/h) and pressures up to 16 bar (232 psi).
Construction
The Alfa Laval flow meter consists of a vertically oriented tapered glass metering tube with a larger end at the top and a metering float that is free to move within the tube.
Operating principle
A metering float rises in the tube in proportion to the fluid flow. The height of the float is an indication of the flow rate, and readings are taken from the scale on the metering tube. The scale indicates the fluid flow as a percentage of maximum flow (100% = max. flow). Different metering floats may be used within the same flow meter, thus making it possible to use the flow meter to measure several different flow ranges.
Application
Flow meters are ideal for measuring feed, permeate, retentate, and diawater flows in membrane filtration modules and plants. The flow meters are made in a hygienic design. All materials comply with FDA regulations, and all product wetted parts are made of stainless steel (AISI 316L) and polysulphone. For float materials, please refer to the table overleaf.
Working principle
A float is elevated in the tapered glass metering tube in proportion to the fluid flow. Readings are taken from the scale on the metering tube. The scale shows the flow as a percentage of maximum flow (100% = max. flow). Different floats can be used with the same flow meter, thus making it possible to use it for a number of flow ranges.
Options
Flow meters for higher flow.
Technical data
Temperature range: . . . . . . . . . . . . . 0-100°C
Max. pressure: . . . . . . . . . . . . . . . . 1.6 MPa (16 bar)