Botlek Studiegroep Basics Electro Magnetic Flowmeters

Transcription

1 Arjan Meerveld, ABB b.v. / 2 juni 2016 Botlek Studiegroep Basics Electro Magnetic Flowmeters ABB Group 8 June 2016 Slide 1

2 Measuring Principle of EMF Faraday s law (year 1831) Measurement electrodes Magnetic field Voltage U

3 Measurement System Flow sensor Magnet Coils Measuring Electrodes Many materials Tube Lining Many materials ABB Slide 3

4 Measurement Technique DC or AC Magnet Coil Excitation? DC DC DC Magnet Coil Excitation Covers 90% of all applications Hz alternating DC current Electrode voltage is measured after magnetic field stabilization Signal measurement period lengths is vital to eliminate noise Pulsed DC Applications Suitable for continuous flow Highest Accuracy and Stability Waveform automatically eliminates background noise Magnetic Field Stabilisation Signal Measurement Period Magnetic Field Stabilisation Signal Measurement Period For conductive liquids above 5 µs/cm Average Signal ABB Slide 4

5 Measurement Technique DC or AC Magnet Coil Excitation? AC AC AC Magnet Coil Excitation Coil is fed with 70 Hz AC current. Electrode voltage is measured continuously at all times AC Magnet Coil Excitation is ideal for Fast batching or filling applications Liquids with high content of solids e.g. mining slurries, paper pulps or yoghurt with fruit particles 2 phase liquids (water and pulp or pulp and Sodium silicate) Pulsating or rapidly changing flow Low conductivity fluids (> 0,5 µs/cm) Signal Measurement Period Signal Measurement Period ABB Slide 5

6 Advantages and limitations of EMF techniques Advantages No moving parts Unobstructed flow path Ability to handle corrosive and erosive liquids Minimum flow conditioning required Ideal for slurries Measures from zero Very High accuracy bar C Limitations Only conductive fluids can be metered (> 5 µs/cm) Physical pressure and temperature limits Heavy coatings (insulating or shorting) can result in measurement errors ABB Slide 6

7 Measurement System Flow Sensor Inline Sensor Separate coil housing w/o coil housing Available as Only available as Full bore Reduced bore Reduced bore Insertion Probe No meter tube Insertion probe ABB Slide 7

8 Measurement System Flow Sensor Flange connection Wafer connection Other Process connections ABB Slide 8

9 Measurement System Transmitter Provides the power source for the sensor coils Power supply options Mains AC High Voltage 24 V AC/DC Low Voltage Power Battery Renewable energy (solar / wind) ABB Slide 9

10 Measurement System Transmitter Power 4-20mA / HART Frequency / Pulse / Alarms Transmitter Measures the electrode signal voltage Calculates the Volumetric flow rate and totalizes the flow Provides the outputs, for example 4-20mA / HART Frequency/Pulse Alarms Communication Profibus, Foundation Fieldbus Modbus, Wireless ABB Slide 10

11 Measurement Technique Installation Conditions I The Flow Profile must be established for the Sensors Straight pipe lengths for in and outlet are required Inlet Sensor Outlet Diameter (DN) Reduced bore 0xDN 0xDN Insertion 50xDN 50xDN Standard inline 3xDN 2xDN Do not install fittings, manifolds, valves etc. in front of the meter Enhanced Sensor geometry allows reduction of straight pipe length. As the specific demands are varying, check the specific datasheets. ABB Slide 11

12 Measurement Technique Installation Conditions II Meter tube must always be kept full. Do not install the sensor at a high point, or in a location likely to drain. With vertical installation recommended flow direction is upwards ABB Slide 12

13 Measurement Technique Installation Conditions III Grounding Ring Grounding Ring Grounding of the Fluid Plastic pipes or pipes with insulating lining ground is provided by Grounding ring Grounding electrodes Choice of materials available to ensure corrosion resistance Grounding electrode ABB Slide 13

14 Applications General Application Areas Industries Chemical & Petrochemical Food & Pharmacy Pulp & Paper Water / Waste Water Mining and Metal Application Dosing of additives, fine chemicals, corrosive liquids like acids, bases, solvents, dyes, hazardous areas etc. Dairy products, beer, wine, wort, beverage concentrates, fruit juices, molasses, drinking water, chemicals, cosmetics, lotions, shampoos Paper pulp. wood pulp, additives, water, waste water, Latex and clay flow, Liquor Waste water, clarifier sludge, flock material, drinking water in municipal supply network, pumping stations, dams, springs Highly abrasive Slurries, Cooling water Oil & Gas and Refining Power & Utilities High pressure injection (water), Waste Water Cooling water loops, water/waste water networks, pump test stands, Coal slurry, feed water to boiler, lime slurry ABB Slide 14

15 Application Limitations Applications in general Only conductive liquids > 0,5- or 5 µs/cm can be measured Pressure < 250 bar Temperature < 180 C Liquids which form conductive or non-conductive layers on the electrodes Solid- or gas content of liquids Abrasive- or corrosive fluids (choose the right Liner- and electrode material) Measuring time (pulsating flow or dosing applications) ABB Slide 15

16 Application Limitations & possibilities Electrodes beware of corrosion and coating - I Electrode Material Stainless Steel Hastelloy B Hastelloy C Titanium Tantalum Platinum Iridium Tungsten Carbide Different electrode materials available Extended Reliability through double sealed electrodes Special edged electrodes for fluids that tends to coat and isolate the signal (Swedish design).

17 Application Limitations & possibilities Liners abrasive or corrosive fluids - II Liner Material Hardrubber Softrubber PTFE PFA ETFE Different liner materials available Ceramic Carbide liner for abrasive fluids such as sand/water mixtures

18 Application Limitations & possibilities Liners abrasive or corrosive fluids - II Polyurethane Softrubber Hardrubber Thick PTFE Abrasion Corrosion PTFE PFA Ceramic Carbide Bad Good Excellent ABB Group 8 June 2016 Slide 18

19 Application Limitations & possibilities DC and AC mags during pulsating flow - III DC EMF output 6 1/4 Hz DC Flow 70 Hz AC AC EMF output ABB Group 8 June 2016 Slide 19

20 Application Limitations & possibilities How to optimize my process with Gas Bubble Detection? - IV Reduce Maintenance Costs Dry run protection of pumps Air intake recognition of the pump due to gas bubbles Ensure Exact Measurement Gas bubbles have effect on measurement accuracy ABB Group 8 June 2016 Slide 20

21 Application Limitations & possibilities How to optimize my process with Gas Bubble Detection? - IV Electrode E1 Electrode E2 Signal Detection Comparison to Gas Bubble Threshold V E1 V E2 Injection of a specific signal at electrode E1. Detection of the corresponding signal at electrode 2. Evaluation of the signal With 1,5... 2% gas in the water, the measuring effect causes the gas bubble value to exceed the threshold. An alarm will be initiated ABB Group 8 June 2016 Slide 21

22 Application Limitations & possibilities How to optimize my process with Coating Detection? - V Ensures exact measurement Insolating or conductive coatings inside the meter tube have effect on measurement accuracy Ensures constant product quality due to meter accuracy remaining the same Improves planning of maintenance work Prevents cost-intensive plant outages ABB Group 8 June 2016 Slide 22

23 Application Limitations & possibilities How to optimize my process with Coating Detection? -V Field test in treatment plant Activated sludge containing Fe3Cl forms conductive layer within the meter tube in a 3 weeks time Size DN100 (4 ) Conductivity 750µS/cm Coating Value 170 prior cleaning 115 after cleaning with a high-pressure cleaner 103 after intensive cleaning, meter tube removed from pipe work ABB Group 8 June 2016 Slide 23

24 Application Limitations & possibilities How to save maintenance costs with Grounding Check? - VI Electrode coating Electrode Fault Wiring Error Grounding Fault Transmitter Drift 5 out of the 12 most valuable instrument diagnostics Benefit for magmeter customers ABB Group 8 June 2016 Slide 24

25 Application Limitations & possibilities How to save maintenance costs with Grounding Check? - VI Incorrect or faulty grounding belongs to the most frequent reasons for incorrect flowrate readings Grounding Check analyses the quality of the grounding (Frequency Spectrum) w ith ground w ithout ground Frequency Spectrum on the grounding line Amplitude Frequency Grounding Check indicates the 4 highest Noise-amplitudes within the frequency spectrum Grounding Check for a most accurate flow measurement from day one ABB Group 8 June 2016 Slide 25

26 Application Limitations & possibilities Safety MAG meters are SIL 2 Certified - VII Functional Safety per IEC / EN61508 Benefit Applicable for flow monitoring up to SIL 2 Assessed by an independent authority (TÜV) acc to IEC/EN Continuous flow measurement independent of product fluid Continuous self-diagnostic Easy to install and start-up Proof Test without the need to remove meter from the line ScanMaster Verification Tool

27 Finally Visit our Product Selection assistant! ABB Group 8 June 2016 Slide 27

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