////General information about CORIOLIS MASS FLOW meters

GENERAL INFORMATION ABOUT CORIOLIS MASS FLOW METERS

A Coriolis-based flowmeter, SITRANS F C MASSFLO is designed to measure any liquids and gases. This versatile instrument provides accurate measurement of mass flow, volume flow, density, temperature and fraction flow.

Features

High level of flexibility

  • wide range of products
  • Plug & Play for all signal converters with one single flow converter interface
  • compact or separate installation using the same signal converter and flow converter

Simple commissioning

All SITRANS F Coriolis flow meters feature a SENSORPROM® memory unit which stores sensor calibration data and transmitter settings for the lifetime of the product. Factory settings matching the sensor are thus stored in the SENSORPROM® unit and can always be retrieved.

The flowmeter starts operating as soon as the startup procedure is complete, without any initial programming.

The factory settings matching the sensor are stored in the SENSORPROM® unit. Also customer specified settings are downloaded to the SENSORPROM® unit. Should the signal converter be replaced, the new converter will upload all previous settings and resume measurement without any need for reprogramming.

Simple repair

  • Expanded self-service menu and simplifies troubleshooting and testing instrument.
  • Reprogramming is not required when replacing the signal converter. SENSORPROM automatically updates all settings after initialization.

Future focused

The USM II – Universal Signal Module “Plug & Play” – provides easy access to the flow measurement and its integration in virtually all protocols and bus systems. It guarantees a simple upgrading of the meter to future bus and communication platforms.

Scope

Mass flow measuring devices based on the Coriolis measurement principle are suitable for measuring any liquids and gases. The measurement is carried out regardless of changes in such conditions and process parameters as temperature, density, pressure, viscosity, conductivity and flow profile.

The installation of the flow meter is very simple due to this diversity. This Coriolis flowmeter is known for its high accuracy over a wide dynamic range, which it is a decisive argument for the use in many applications.

Functions

The flow measuring principle is based on Coriolis law of movement. The flowmeter consists of a flowmeter type MASS 2100 or MC1 and a signal converter MASS 6000.

The MASS 2100 / MC1 flow converter is driven by an electromechanical excitation circuit that excites flow-induced vibration within piping systems at the resonant frequency.

Two pickups are placed symmetrically on either side of the driver to provide position signals for digital processing. When the media flows through the sensor, Coriolis force will act on the measuring tubes and cause deflection which can be measured as a phase shift between Pickup 1 and Pickup 2. The phase shift is proportional to the mass flowrate.

The amplitude of the driver is automatically regulated via a “Phase Locked Loop” to ensure a stable output signal from the two pick-ups in the range of 80 to 110 mV.

The temperature of the flow transducer is measured in a Wheatstone bridge circuit via a PT1000 (four-wire design).

The signal of both sensors proportional to the flow rate, the measured temperature value and the excitation frequency are supplied to the MASS 6000 signal converter and converted into signals proportional to the flow rate, which serve to calculate the mass flow rate, volumetric flow rate, fractional flow rate, temperature and density.

Analog-to-digital conversion is performed in a low noise ASIC with a signal resolution of 23 bits. The signal transfer function is based on the patented DFT (Discrete Fourier Transformation) technology. ASIC is the State Machine Gate Ar-ray, which provides fast processing and smoothing of signals and causes the mass flow rate to be updated at 30 Hz.

Under adverse installation and operating conditions, the performance of the flowmeter can be improved by using a noise filter integrated in the ASCI. This can significantly reduce typical interference caused by process noise such as pump vibrations, mechanical vibrations or valve vibrations.

For communication purposes the ASIC has a CAN interface with a Siemens specific protocol. This concept is known as the USM II (Universal Signal Module) concept. The idea is that extra output modules or communication modules can be connected to this bus, making it possible to configure the flowmeter for the
precise task in hand.

When the internal CAN bus detects the installed module, it is automatically programmed to factory settings via the SENSORPROM memory unit, and the new menu is visible in the MASS 6000 display.

SENSORPROM flow memory unit

Currently the USM platform handles all present and future communication protocols, e.g., PROFIBUS DA, PROFIBUS PA, HART, CANopen, De-viceNet, MODBUS.

Integration

Installation, general instructions

Installation of MASS 2100 and MC1 flow transmitters

Installation requirements/System design information

The SITRANS F C MASSFLO mass flowmeter is suitable for in- and outdoor installations. The standard instrument meets the requirements of Protection Class IP67/NEMA 4X / IP65/NEMA 4. The flowmeter is bidirectional and can be installed in any orientation.
It is important to ensure that the meter tubes are always completely filled with homogeneous fluid. Otherwise measuring errors may occur.

The corrosion resistance of the fluid wetted materials must be evaluated.

The pressure drop through the sensor is a function of the properties of the fluid and the flow rate. The Sizing Program (download from http:///www.siemens.de/flow-productsizing) can be used to calculate the pressure drop.

The following points are to be considered during installation:

Installation orientation

  •  MASS 2100 flow transducer
    The optimal installation orientation is horizontal.
  •  MC1 flow transducer
    The optimal installation orientation is vertical with the flow upwards. See next pages.

Supports

  • In order to support the weight of the flowmeter and to ensure reliable measurements when external effects exist (e.g. vibrations), the sensor should be installed in rigid pipelines. Two supports or hangers should be installed symmetrically and stress free in close proximity to the process connections.

Shut off devices

  • To conduct a system zero adjustment, shut off devices are required in the pipeline.
    • in horizontal installations at the outlet for MC1 and the inlet for MASS 2100.
    • in vertical installations at the inlet.
  • When possible, shut off devices should be installed both up and downstream of the flowmeter.

Installation: straight run requirements

  • The mass flowmeter does not require any flow conditioning inlet straight sections. Care should be exercised to ensure that any valves, gates, sight glasses etc. do not cavitate and are not set into vibration by the flowmeter.

System design information

  • The presence of gas bubbles in the fluid may result in erroneous measurements, particularly in the density measurement. Therefore the flowmeter should not be installed at the highest point in the system.
    Advantageous are installations in low pipeline sections, at the bottom of a U-section in the pipeline.
  • Long drop lines downstream from the flowmeter should be avoided to prevent the meter tube from draining.
  • The flowmeter should not come into contact with any other objects. Avoid attachments to the housing.
  • When the cross-section of the connecting pipeline is larger than the sensor size, suitable standard reducers may be installed.
  • If strong vibrations exist in the pipeline, they should be damped using elastic pipeline elements. The damping devices must be installed outside the supported flowmeter section and outside the section between the shut off devices. The direct connection of flexible elements to the sensor should be
    avoided.
  • Make sure that any dissolved gases, which are present in many liquids, do not outgas. The back pressure at the outlet should be at least 0.1 to 0.2 bar (0.5 to 3 psi).
  • Assure that operation below the vapor pressure cannot occur when a vacuum exists in the meter tube or for fluids which boil readily.
  • The sensor should not be installed in the vicinity of strong electromagnetic fields, e.g. near motors, pumps, transformers etc.
  • When operating more than one meter in one or multiple interconnected pipelines, the sensor should be spaced distant from each other or the pipelines should be decoupled to prevent cross talk.

Zero adjustment

  • In order to adjust the zero under operating conditions it must be possible to reduce the flow rate to „ZERO“ while the meter
    tube is completely filled. A bypass line is optimal when the process cannot be shut down. It is important for accurate measurements that during the zero adjustment there are no gas bubbles in the flowmeter. It is also important that the pressure and temperature in the meter tube be the same as that which exists during operation.

Installation guidelines MASS 2100 DI 1.5 (1/16“)

Installation of MASS 2100 sensor

  • The optimal installation is horizontal.

If vertical mounting is necessary, upward flow is recommended to facilitate the removal of air bubbles. To remove the air from the sensor the flow speed in the sensor must be at least 1 m/s.

If there are solid particles in the liquid, especially in connection with low flow, it is recommended that the sensor be mounted horizontally with inlet flange uppermost so that particles are more easily flushed out. To ensure that the sensor does not become partially empty, there must be sufficient counter-pressure on the unit min. 0.1 to 0.2 bar (1.45 to 2.9 psi).

  • Mount the sensor on a vibration-free wall or steel frame.
  • Locate the sensor low in the system in order to avoid an underpressure in the sensor separating air/gas in the liquid.
  • Ensure that the sensor is not emptied of liquid (during normal operation) otherwise incorrect measurement will occur.

Horizontal

Liquid and gas application

Vertical

Использование с жидкостями (слево), использование с глазом (справа)

Installation guidelines MASS 2100 DI 3 … DI 40 (1/8” … 1½”)

Installation of sensor

Horizontal (self-draining)

With low flow, horizontal mounting is recommended, as in this position air bubbles are easier to remove.

Vertical

Vibration

Always locate the flowmeter as far away as possible from components that generate mechanical vibration in the piping.

Cross talk

Cross talk between sensors mounted close to each other may disturb the measurement. To avoid cross talk never mount more than one meter on each frame and mount flexible hose connections between the sensors as shown.

Zero point adjustment

To facilitiate zero point adjustment a shut-off valve should always be mounted in connection with the sensor as a proper zero point setting is essential for a good accuarcy.

Installation guidelines MC1 DN 50 … DN 150 (2” … 8”)

Installation of sensor

The optimal installation orientation is a vertical installation with an upward flow as shown in the following figure. This has the advantage that any solids contained in the fluid will settle downward and gas bubbles will move upward out of the meter tube when the flow rate is zero. Additionally, it is easy to drain the meter tube. Deposits can thereby be avoided.

Vertical orientation:

Vertical installation self-draining (upward flow)

Horizontal orientation:

Horizontal installation

Horizontal orientation, self-draining:

Horizontal orientation, self-draining, α 2° … 4°

Installation in a drop line

The installation recommendation shown in the following figure is only possible if a pipeline reduction or orifice with a smaller cross section can be installed to prevent the sensor from being partially drained during the measurements.

Installation in a drop line

Difficult installation locations

The accumulation of air or gas bubbles in the meter tube can lead to increased inaccuracies. Some difficult installations are shown in the following figure.
Installations at the highest point in the system (figure A) can result in the formation of air pockets which can lead to appreciable inaccuracies.
Another difficult installation condition is immediately upstream of a free discharge (figure B) in a drop line.

2019-09-11T15:05:03+03:00