VAF Instruments ViscoSense ® systems are used for the measurement and control of viscosity of many liquids. Especially designed for fuel oil applications it is used for diesel engines on ships and in land based power plants. PRODUCT BULLETIN 740 V A F I N S T R U M E N T S T O B E R E A L L Y S U R E ViscoSense ® Viscosity Measurement and Control System 1 Fig. 1, ViscoSense ® sensor and housing The benefits of accurate Viscosity control Viscosity control of fuel oil for combustion engines is a necessity. Prevention of engine damage and reduction of maintenance, next to efficiency improvement, are the key factors to choose for the most accurate viscosity control possible. Bunkerings of fuel with unpredictable quality have proven that temperature control of fuel oil is far from reliable and that direct viscosity measurement and control is the only way to achieve the results required. From the experts in viscosity control VAF Instruments have had experience for a long time in the field of viscosity measurement and control. In the 1950's VAF introduced a viscosity sensor for fuel oil. From then on VAF's name for quality, reliability and accuracy has led to the current status of world-market leader in fuel viscosity control. More than 40,000 systems have found their way to ships and plants all over the world. New unique patented measuring principle The VAF Instruments ViscoSense ® is a viscosity sensor with a unique operating principle. The patented measuring principle is based on torsional vibration of a pendulum in liquid. The damping of this electrically controlled vibration is directly related to the viscosity. Through this principle ViscoSense ® achieves the most accurate viscosity measurement possible. ViscoSense ® is a registered trademark of VAF Instruments B.V.
Transcript
VAF Instruments ViscoSense®
systems are used for themeasurement and control ofviscosity of many liquids.Especially designed for fuel oilapplications it is used fordiesel engines on ships and inland based power plants.
P R O D U C T B U L L E T I N 740
V A F I N S T R U M E N T S T O B E R E A L L Y S U R E
ViscoSense®
Viscosity Measurement and Control System
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Fig. 1, ViscoSense® sensorand housing
The benefits of accurateViscosity control
Viscosity control of fuel oil forcombustion engines is anecessity. Prevention of enginedamage and reduction ofmaintenance, next toefficiency improvement, arethe key factors to choose forthe most accurate viscositycontrol possible. Bunkerings offuel with unpredictable qualityhave proven that temperaturecontrol of fuel oil is far fromreliable and that direct viscositymeasurement and control is theonly way to achieve the resultsrequired.
From the experts in viscositycontrol
VAF Instruments have hadexperience for a long time inthe field of viscositymeasurement and control. Inthe 1950's VAF introduced aviscosity sensor for fuel oil.From then on VAF's name forquality, reliability and accuracyhas led to the current status ofworld-market leader in fuelviscosity control. More than40,000 systems have foundtheir way to ships andplants all over the world.
New unique patentedmeasuring principle
The VAF InstrumentsViscoSense® is a viscositysensor with a uniqueoperating principle. Thepatented measuring principleis based on torsional vibrationof a pendulum in liquid. Thedamping of this electricallycontrolled vibration is directlyrelated to the viscosity.Through this principleViscoSense® achieves the mostaccurate viscosity measurementpossible.ViscoSense® is a
registered trademark ofVAF Instruments B.V.
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VAF fuel oil flowmeters also available
Typical system arrangement
FUEL OIL HEATER
VANE METER
FUEL OIL
TO ENGINE
SENSOR
CABLE LENGTH+/- 5 METRES
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Fig. 2, Typical system arrangement
VAF steam / thermal oil valves also available
NOT SUPPLIED BY VAF
Optional outputs
Alarms
Supply
STEAM OR THERMAL OIL
SUPPLY
SUPPLY
CONTROLLER
CONTROLVALVE
INTERFACE BOX
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Features and benefits
As a result of the torsionalvibration technique, the flowvelocity in any direction has noeffect on the measurement.External vibration inputs haveno influence on the accuracy ofthe ViscoSense®.In practice the smooth edgeddesign in the stainless steelpendulum of the sensor makesthe system highly insensitive toadherence and easy to clean.On top of that the closed-loopcontrolled torsional vibrationprinciple, as illustrated infigure 3, is independent ofageing of piezo material,ensuring long term stable andaccurate measurement.
Features
• Stable and accurate in-line measurement
• No moving parts
• Compact light-weight construction
• All SS-316 pendulum
• Smooth edged pendulum
• Torsional vibration measuring principle
• Minimal load on components
• Calibrated for life
• Both viscosity and temperatureoutputs
• A genuine VAF Instruments product
• Type approval from all major classification authorities
• Manufactured by a ISO 9001certificated organisation
User benefits
• Optimal burning efficiency and fuel consumption
• Engine damage prevention and reducedmaintenance
• No preventive maintenance required• Low operating costs
• Easy to install
• No wear due to corrosion• Durable
• Insensitive to adherence• No local servicing costs
• Reliable under all circumstances• Not influenced by vibrations, flow velocity,
dirt particles• No down time
• Minimal ageing and wear effects• Long and trouble-free operation
• No need for re-calibration• No operator training required• No local servicing costs
• No need for separate PT 100transmitter
• Over 60 years of experience• World-market leaders in viscosity control
systems
• To be implemented directly on any ship without additional costs
• Assured constant product quality
PT 100
Driver
Receiver
Fig. 3, Sensor
Operating principle
The sensor itself comprises of asealed stainless steel pendulum,attached to a base plate via atorsion tube.Two piezo elements (driverpiezo’s) are driven by analternating signal causing thependulum to move in a torsionalmanner (Torsional vibration).A second pair of piezo elements(receiver piezo’s) sense thetorsional movement via a
feedback and processorfunction, a signal is returned tothe driver piezo’s to ensurecontinued torsional vibration,whilst the processor functionmeasures the phase differenceof send and receive signals. Thephase differential is then furtherprocessed resulting in a valueof dampening which isproportional to the square rootof the liquids viscosity.
SENSOR
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Interface box
The ViscoSense® Interface boxis a wall mount electronic unit,processing the signals from andto the sensor.It provides 4...20 mA signalsfor remote read-out of viscosityand temperature for a controlleror other system elements.
Fig. 5, Electronic Controller
INTERFACE BOX
Electronic controller
VAF Instruments ViscoSense® canbe supplied with an electroniccontroller, processing the signalsfrom the sensor. It has a built-inPI-control function and gives aninstant read-out of viscosity ofthe liquid. Through the easy frontbutton operable controller youwill have acces to the followinguser-friendly features:
• PI control function for viscositycontrol
• Viscosity indication• 4...20 mA output or relay
output for valve control• 4...20 mA output for remote
read-out• Manual operation of steam or
thermal-oil control valve (no feedback)• High and low viscosity alarms
Optional
• Temperature indication• Temperature control
CONTROLLER
Fig. 4, Interface box
Technical specification
Sensor
Viscosity range : 0...25 or 0...50 mPa·s for fuel oil applications, other ranges on request
Resolution : +/- 0.1 mPa·sAccuracy
Viscosity : +/- 2% instantaneous, with a minimum of 0.5 mPa·s
Temperature : < 1˚CResponse time : Less than 1 minuteLiquid temperature : max. 170˚CFlow rate : max. 20m3/h at 0...25 or 50 mPa·s
(in 2” housing)Pressure rating : PN40Materials
Housing : Ductile ironInner parts : Stainless steel 316
Protection class : IP65Process connections : Flanges DN 50 mm (2”), DIN, ANSI
or JISWeight
Sensor : 1 kg.Housing : 8,5 kg.
* Note : This sensor is suitable for use in hazardous zones I and II. For zone 0 ViscoSense EEX version is required (consult factory).
auto/manual buttonAmbienttemperature : 0-60˚CProtection class : DIN 40050, IP54 (Facia only)Electricconnections : Terminals 6.3 x 0.5 mmWeight : 0.8 kg
ControlsInput
Viscosity : 4...20 mATemperature : 4...20 mA (optional)
OutputContacts : 2 relays, 2A/250 V (standard)Control action : If measured value is higher than setpoint
value, the ‘raise’ output relay is activated to open control valve
Current : 4...20 mA (optional)
Alarm feature : Non-latching band alarm, adjustable from 0 to 20% above and below setpoint. 1 potential-free SPDT contact, 1A/264 VAC rating (NO/NC)
Read-outDisplay : 4-grid, 7-segment LED, decimal point
adjustableScale range : 0...25 mPa·s/0...50 mPa·s (or as ordered)Alarm indication : By means of one dedicated front panel LEDOutput indication: By means of two dedicated front panel LED’sOptions : Many variations available.
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In-line viscosity measurement in industrial applications
The ViscoSense® sensor is also suitable for the in-linemeasurement of viscosity of many liquids in industrialapplications. Because individual applications need specialattention please contact VAF Instruments for a tailor madesolution.
Viscosity control systems
In combination with ViscoSense® VAF Instruments offers arange of viscosity control systems. Please refer to ourPublication Bulletin PB742 for additional information onelectrical heater control systems and control system accessories.
SENSOR CONTROLLER
Technical specification
Interface box
Supply voltage : 115/230 VAC, 50/60 Hz selectable (fluctuations should not exceed +/- 10% of the nominal voltage).
Ambient temperature : -20... +55˚CHumidity range : 0... 95% RHProtection class : IP 65Mounting : Wall mountingInstallation category : IPollution degree : I Acc. to IEC 664Weight : 3 kg.
INTERFACE BOX
Dimensions
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Flange type
DIN PN 10/16/25/40
ANSI 150 RF
ANSI 300 RF
JIS 10K
JIS 16/20K
JIS 30K
C
165
152.4
165
155
155
165
E
125
120.6
127
120
120
130
F
102
92
92
100
100
105
N x ØD
4 x 18
4 x 19
8 x 19
4 x 19
8 x 19
8 x 19
M
3
1.6
1.6
2
2
2
Dimensions (mm)
Fig. 6, Sensor DN 50
Fig. 8, Electronic Controller
SENSOR Signal cable length: 5 meters
INTERFACE BOX
CONTROLLER
Fig. 7, Interface box
Dimensions
Dimensions
Ordering information
V A F I N S T R U M E N T S T O B E R E A L L Y S U R E
