vortex flowmeter - fishermeter.com · principle is based on the development of a karman vortex...
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liquid gas steam
Vortex flowmeter
FIS
HE
RM
ET
ER
VT4000
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VT4000
◆ Optimum measuring process reliability enabled by Digital Signal Processing (DSP)
◆ Measurable medium: liquid, gas and steam
◆ High working pressure, 42MPa (max.)
◆
No moving parts and reliable stainless steel structure
◆
Optional double sensors design with higher stability and reliability
◆
VT4000 is fitted with HART communication
◆
±1.0% ◆ Output: 4-20mA analog signal & configurable pulse output
1
Measuring accuracy:
FISHERMETER
Technical parameter
Typical Diameter
Nominal pressure
Fluid temperature
Sensor design
Body material
Accuracy
Repeatability
Flow Range
Converter type
Wafer DN15~DN300, Flange DN15~DN600, Insertion >= DN300
(1.6, 2.0, 2.5, 4.0, 5.0, 6.4) MPa. Other special pressure classes upon request
Standard(-40~+120)℃, M-tem(-40~+250)℃, H-tem(-40~+320)℃
Single sensor double sensors
SS304, 316L, HC and other materials upon request
< 0.33%
1:10~1:20
Communication
Display
T/P compensation
Supply power
Output
Battery power
Linear rectification
Low flow cut-off
HART Protocol
Current:4 -20mA
PulseVoltage
L<1V, H ≥5V
Ex-Design
Protection Class
Applicable medium
Ambient conditions
Ex ia II CT5,Ex d II CT5
IP65
Gas, liquid, steam
Ambient temperature: (-40~+60)℃
Relative humidity: 5%~90% Atmospheric pressure: (86~106)kPa
2
or
±1.0%
Compact & Remote
LCD
In preparation
15~28 V DC
:
Optional
Available
Available
Item VT4000
FISHERMETER
Fig.1
Measuring principle
The vortex flowmeter is used for measuring the flow velocityvof gases and liquids in pipelines flowing full. The measuring
The periodic shedding of eddies occurs first from one side
The vortex shedding frequency f is proportional to flow velocity v and inversely proportional to the width of the shedder d:
f = St × v / d
St, the Strouhal Number, is a dimensionless quantity. If the geometrical shape and dimension of shedder are designed appropriately, St is a constant over the wide range of Reynolds number Re (Figure 3).
Re = v × D / υ υ: Kenematic viscosity of fluid
D: Meter body diameter Strouhal num
ber St
The vortex shedding frequency used to measure the flowrate is only a function of the flow velocity regardless of fluid density and viscosity. The pressure pulsation generating with vortex shedding will be detected by the Piezo-Sensor and converted into pulse signal corresponding to the vortex frequency in the test circuit, and the signal converter will convert this pulse signal into 4-20 mA normalized current signal and output it.
3
FISHERMETER
Fig.2
Fig.3
Principle is based on the development of a Karman vortex shedding street in the wake of a body built in the pipeline.
and then from the other side of a bluff body (vortex-shedding-body) installed perpendicular to the pipe axis. Vortex shedding generates a so-called Karman vortex street withalternating pressure conditions whose frequency isproportional to the flow velocity. (Fig.2)
ρ ρn1,013· p+
1,013-------------------------× 273
273 T+--------------------×=
QV Qnρnρ------ Qn
1,0131,013 p+------------------------- 273 T+
273--------------------×= =
QVQm
ρ----------=
ν ηρ---=
Flowmeter Size SelectionThe flowmeter size is determined from the maximum operating flowrate QVmax. To achieve the maximum flow range, this value should not be less than one half of the maximum flowrate for the meter size (RangeMax), but can be selected as low as 0.15 RangeMax. The start of the linear flow range is a function of the Reynolds Number.
If the flowrate to be measured is specified as normal flowrate, (normal conditions: 0 °C, 1013 mbar) or as mass flowrate, the values must first be converted to actual flowrate values at oper-ating conditions and then the appropriate meter size can be selected from the Flow Range Tables (Tbls. 1, 2, 3).
1. Convert normal density ( ) --> operating density ( )
2. Convert to flowrate at operating conditions (QV)a) starting with normal flowrate (Qn) -->
b) starting with Mass flowrate (Qm) -->
3. Dynamic viscosity ( ) --> kinematic viscosity ( )
= Operating density [kg/m3]
N = Normal density [kg/m3]
p = Operating pressure [bar]
T = Operating temperature [°C]
QV = Operating flowrate [m3/h]
Qn = Normal flowrate [m3/h]
Qm = Mass flowrate [kg/h]
= Dynamic viscosity [Pas]
= Kinematic viscosity [m2/s]ρn ρ
η ν
ρ
ρ
η
ν
QVm
in [m
3 /h]
[10-6m2/s = cSt]ν
0.1
1
10
100
1000
0.1 1 10
DN15
DN50DN40
DN25
DN200
DN150
DN100DN80
DN300
DN250
Fig. 4: Minimum Flowrate, Liquids as a Function of the Kinematic Viscosity
FISHERMETER
4
Flow Ranges, Liquids
Pressure Drop, LiquidsSee Fig. 5 for water (20 °C, 1013 mbar, = 998 kg/m3).For other densities ( ) the pressure drop can be calculated using the following equation:
= Pressure drop fluid [mbar]
= Pressure drop water [mbar] (from Fig. 5)
Static Overpressure, LiquidsTo avoid cavitation when metering liquids a positive static pres-sure (back pressure) is required downstream from the flowmeter. The required pressure can be calculated using the following equation:
p2 ≥ 1.3 x pvapor + 2.6 x
p2 = positive downsteam static pressure [mbar]
pvapor = vapor pressure of fluid at the operating temperature [mbar]
= pressure drop, fluid [mbar]
Example for liquids:Find the flowmeter size for metering 55 m3/h liquid with a density of 850 kg/m3 and a kinematic viscosity of 2 cSt = (2 x 10-6 m2/s).
1. QV = max. 55 m3/h --> DN50[2”] (per Tbl. 1): QVmax = 70 m3/h
2. Flow range start, linear, at 2 cSt, (from Fig. 5): QVmin = 6 m3/h
3. Press. drop (Qv = 55 m3/h) at = 850 kg/m3: = 425 mbar
MeterSize
DN Inch
DIN ANSIQVmin1) RangeMax Frequency QVmin1) RangeMax Frequency[m3/h] [m3/h] [Hz] [m3/h] [m3/h] [Hz]
Std. HT at Qvmax Std. HT at Qvmax 15 1/2“ 0.5 - 6 370 0.5 - 5.5 450 25 1“ 1.6 3.6 18 240 1.6 3.6 18 400 40 1-1/
2“2.4 9.6 48 190 2.5 9.6 48 270
50 2“ 3 14 70 140 3 13 66 176 80 3“ 10 34 170 102 10 32 160 128100 4“ 10 54 270 72 12 43 216 75150 6“ 30 126 630 50 33 106 530 50200 8“ 70 220 1100 45 70 187 935 40250 10“ 70 340 1700 29 82 289 1445 36300 12“ 135 480 2400 26 135 408 2040 23Tbl. 1: Flow Ranges, Liquids at 20 °C, 1013 mbar,
= 998 kg/m3)1) Std. 280 °C Version / HT = High temperature design (fmax = 400 °C
ρ
ρρ
∆p' ρ998---------- ∆p×=
∆p'
∆p
∆p'
∆p'
ρ ∆p'
QV [m3/h]
[mba
r]∆p
Example425 mbar
55 m3/h
DN
15
DN
25
DN
40
DN
50
DN
80
DN
100
DN
150
DN
200
DN
250
DN
300
1
10
100
1000
0.1 1 10 100 1000 10000
Fig. 5: Pressure Drop, Water (20 °C, 1013 mbar, = 998 kg/m3), DIN-Designρ
FISHERMETER
5
Flow Ranges, Gas/Steam
Example for Gases:Find the flowmeter size for metering 2540 m3/h (qn) CO2-Gas; Temp. = 85 °C, Press. = 5 bar a.For details see Page 5 “Flowmeter Size Selection”
= 1.97 kg/m3 (CO2)
1. Convert --> : =7.4 kg/m3
2. Convert m3/h (qn) --> m3/h (qv): QV = 676 m3/h (qv)--> Selection : DN 80[3”] (QVmax = 1200 m3/h) (qv)
3. Pressure drop at = 7.4 kg/m3: = 100 mbar
4. Flow range start at = 7.4 kg/m3 (from Fig. 7): QVmin = 45m3/h, Convert m3/h (qv) --> m3/h (qn): QVmin = 169 m3/h (qn)
Pressure Drop, Gas/SteamSee Fig. 8 for air (at 20 °C, 1013 mbar, = 1.2 kg/m3)For other fluid densities the pressure drop can be calculated using the following equation:
= Pressure drop fluid [mbar]
= Pressure drop air [mbar] (from Fig. 8)
Normal Densities of Various Gases:
MeterSize
DN Inch
DIN ANSIQVmin1) RangeMax Frequency QVmin1) RangeMax Frequency[m3/h] [m3/h] [Hz] [m3/h] [m3/h] [Hz]
Std. HT at Qvmax Std. HT at Qvmax 15 1/2“ 4 - 24 1520 5 - 22 1980 25 1“ 15 30 150 2040 12 16 82 1850 40 1-1/
2“30 78 390 1550 21 68 340 1370
50 2“ 40 100 500 1030 43 90 450 1180 80 3“ 100 240 1200 700 78 190 950 780100 4“ 150 380 1900 500 120 360 1800 635150 6“ 300 900 4500 360 260 810 4050 405200 8“ 430 1600 8000 285 420 1360 6800 240250 10“ 810 2800 14000 260 820 2400 12000 225300 12“ 1410 4000 20000 217 1300 3400 17000 195
Tbl. 2: Flow Ranges, Gases at = 1.2 kg/m3)
1) Std. 280 °C Version / HT = High temperature design (fmax = 400 °C
ρ
ρn
ρn ρ ρ
ρ ∆p'
ρ
Gas Normal Density [kg/m3]Acetylene 1.172Air 1.290Ammonia 0.771Argon 1.780Butane 2.700Carbon dioxide 1.970Carbon monoxide 1.250Ethan 1.350Ethylene 1.260Hydrogen 0.0899Methane 0.717Natural gas 0.828Neon 0.890Nitrogen 1.250Oxygen 1.430Propane 2.020Propylene 1.915
ρ
∆p' ρ1,2-------- ∆p×=
∆p'
∆p
QVm
in [m
3 /h]
[kg/m3]ρ
DN15
DN50DN40
DN25
DN200DN150
DN100DN80
DN300
DN250
1.0
10.0
100.0
1000.0
10000.0
0.10 1.00 10.00 100.00
Fig. 6: Minimum Flowrates, Gas/Steam as a Function of the Fluid Density, DIN-Design (280 °C)
FISHERMETER
6
QV m
in [m
3 /h]
[kg/m3]ρ
DN50DN40
DN25
DN200
DN150
DN100
DN80
DN300DN250
1.0
10.0
100.0
1000.0
10000.0
0.10 1.00 10.00 100.00
Fig. 7: Minimum Flowrates, Gas/Steam as a Function of the Fluid Density, DIN-Design (HT)
[mba
r]∆
p
QV [m3/h]
DN
150
DN
200
DN
250
DN
15
DN
25
DN
50
DN
40
DN
80D
N10
0
DN
300
0.10
1.00
10.00
100.00
1.0 10.0 100.0 1000.0 10000.0 100000.0
Fig. 8: Pressure Drop, Air (20 °C, 1013 mbar, = 1.2 kg/m3), DIN-Design
FISHERMETER
7
Flowrates Saturated Steam [kg/h] Example for Saturated Steam:Find the flow range for DN 50 [2”] at 7 bar (a).--> from Tbl. 3: DN 50[2”]: 101 - 1835 kg/hAdditional information: Sat. steam temp.= 165 °C
Sat. steam dens.= 3.67 kg/m3
Tbl. 3: Saturated Steam Flow Ranges, DIN-Design
p[bar a]1 1.5 2 3 4 5 6 7 8 9 10 12 15 25 30 35 40 45 50 Meter Size
Inch DN1/2“ 15 min
max2
143
215
277
408
529
64976
1088
11100
11112
12124
13147
14182
21300
25360
29420
33480
38544
42609
1“ 25 minmax
989
13129
17170
25248
29324
32401
35476
38551
40624
43699
45773
49920
541140
781875
942250
1092625
1253000
1413401
1583804
1-1/2“ 40 minmax
18230
26335
34441
50644
58842
641041
701236
761431
801622
851817
892009
992391
1222964
2014875
2415850
2826825
3227800
3658841
4089890
2“ 50 minmax
24295
34430
45565
66825
771080
861335
941585
1011835
1072080
1142330
1192575
1303065
1453800
2086250
2497500
2918750
33310000
37711335
42212680
3“ 80 minmax
59708
861032
1131356
1651980
1932592
2153204
2343804
2524404
2684992
2845592
2986180
3297356
4089120
67115000
80518000
93921000
107324000
121727204
136130432
4“ 100 minmax
891121
1291634
1702147
2483135
2904104
3225073
3616023
4186973
4747904
5318854
5869785
69811647
86514440
142323750
170828500
199233250
227738000
258143073
288748184
6“ 150 minmax
1772655
2583870
3395085
4957425
5809720
64412015
72214265
83616515
94718720
106120970
117323175
139627585
173034200
284656250
341567500
398478750
455490000
5162102015
5774114120
8“ 200 minmax
2544720
3706880
4869040
71013200
86317280
106721360
126725360
146729360
166333280
186337280
205841200
245049040
303860800
4996100000
5995120000
6995140000
7994160000
9061181360
10136202880
10“ 250 minmax
4788260
69712040
91515820
133723100
156530240
174037380
194944380
225651380
255758240
286565240
316672100
376885820
4672106400
7684175000
9221210000
10758245000
12295280000
13936317380
15590355040
12“ 300 minmax
83211800
121317200
159322600
232733000
272443200
309253400
330063400
355173400
378083200
400193200
4269103000
5081122600
6300152000
10361250000
12434300000
14506350000
16578400000
18791453400
21021507200
Density sat[kg/m3] 0.59 0.86 1.13 1.65 2.16 2.67 3.17 3.67 4.16 4.66 5.15 6.13 7.60 12.50 15.00 17.50 20.00 22.67 25.36
Temp. Tsat [°C] 99.6 111.4 120 133 144 152 159 165 170 175 180 188 198 224 234 242 250 258 264
ρ
FISHERMETER
8
Exia II CT5
VT
Converter type 4 Type of connection
Wafer
(DN15~DN300)
0
Flange (DN15~DN600) 1
Insertion (≥DN350)
2
Type of converter
Compact 0
Remote 1
Measuring medium Liquid 0 Gas 1 Steam 2
Materials
C
M
Meter
Size
DN15
15
DN20
20
DN25
25
DN40
40
DN50
50
DN80
80
DN100
1H
DN125
1T
DN150
1F
DN200
2H
DN250
2F
DN300
3H
...
...
8H
Probe type
Standard
(-40~+120)℃
0
High
temperature (-40~+250)℃
1
Super
temperature (-40~+320)℃
2
Sealing
Graphite
0
PTFE
1
Others
9
Explosion proof
None
A
B
C
None
0
1
9
DN800
Pressure RatingPN16PN20PN25PN40
BLC
D
Others
Ex ia II CT5Ex d II CT5
LC
600LB
PN63
150LB
EFPN100
300LBNP
K
316LSS304
HCOthers
AB
HART
Order series
G
FISHERMETER
Ordering Selection of Vortex Flowmeter
Yes
Profile and installing dimension
Flange connection (mm)
DN
15
20
25
40
50
80
100
125
150
200
250
300
PN 40
40
40
40
40
40
16/40
16/40
16/40
16/25
16/25
16/25
L 200
200
200
200
200
200
250
250
300
350
450
500
H 300
300
300
340
350
365
375
390
400
425
450
475
d 15
20
25
40
50
80
100
125
150
200
250
300
D 95
105
115
150
165
200
220/235
250/270
285/300
340/360
405/425
460/485
k 65
75
85
110
125
160
180/190
210/220
240/250
295/310
355/370
410/430
d1 14
14
14
18
18
18
18/22
18/26
22/26
22/26
26/30
26/30
N 4
4
4
4
4
8
8
8
8
12
12
12/16
b 14
16
16
18
20
24
22/24
22/26
24/28
24/30
26/32
28/34
DN PN 15 25
20 25
25 25
40 25
50 25
80 25
100 25
125 25
150 25
200 25
250 25
300 25
L 65
65
65
65
65
65
65
65
65
100
100
120
H 310
310
310
315
320
320
330
345
360
400
425
460
D 55
55
55
85
100
130
150
175
200
250
300
350
d
Wafer connection (mm)
15
20
25
40
50
80
100
125
150
200
250
300
10
FISHERMETER
Installation The installation site and fixing manner of flowmeter will have a direct impact on its application. Incorrect installation will influence the measuring accuracy and the service life of the flowmeter, and even cause permanent damage to it,so the following items shall be referred during the installation.
Inlet and outlet sections The installation of flowmeter shall satisfy the minimum requirements for the inlet and outlet straight section as shown Figure 9, or it will have a serious impact on the measuring accuracy or even on normal function of flowmeter.
Figure 9 Length of inlet and outlet straight section (D: The nominal internal diameter of the meter)
Installation for high fluid temperatures When the temperature of medium in the horizontal pipe is above 180 , it is recommended that the ℃ remote type of flowmeter or side mounting be chosen, that is to say, the head of flowmeter is not on the top of the pipe, because high temperature may damage the electronic circuit in signal converter. Correct installation manner is as shown in Fig.10
Fig.10: Installation for high fluid temperatures Fig.11: Low installation shall be avoided for steam measurement (Temperature ≥180 )℃ .
Installation for steam measurement
When the measured medium is saturated steam or humid gas, the flowmeter shall not be installed at the lowest part of pipe line (Fig.11), because the steam may condense into liquid at the lower part of pipe line, causing coexisting of water and steam, whichmay result in failure in performance of flowmeter and greater measuring errors. In addition, when the steam device is being opened, water hammer may appear at the lower part of pipe line.
11
FISHERMETER
Installation for liquid measurement
Fig.12: High installation shall be avoided for liquid measurement
Fig.13: Up-to-down flow shall be avoided for installation of vertical pipe line
Thickness of thermal insulation layer
Fig.14: Thickness of thermal insulation layer
Fig.15:
Required distance for
flowmeter maintenance
Service clearance
Installation of Remote type flowmter
12
FISHERMETER
When the measured medium is liquid, the liquid shall be full of the pipe, and it is better to make the liquid flow from a lower position to a higher or flow horizontally.
The flowmeter shall not be installed at the highest part of pipe line (Fig.12), because the air bubbles may gather there and cause a serious impact on the measuring accuracy.If the pipe is vertical, the liquid shall not flow from up to down (Fig.13), or the pipe will not be full, which may seriously influence the measuring accuracy and cause failure in performance of flowmeter.
If the pipe line needs to be kept warm, the thickness of thermal insulation layer covering the instrument shall not exceed 50 mm (Figure 14). The excessive thickness may cause a rise in temperature of signal converter which leads to a damage.
More than 200 mm clear space for mounting, dismounting and maintenance shall be allowed at the top of flowmeter during installation (Figure 15).
The installation of separate flowmeter body is identical to that of compact flowmeter. The signal converter must be firmly fixed on the wall or in the cabinet. The longest transmission distance between the signal converter and primary body is 10 meters, and the connecting cable is two-core shielded cable. The shorter the signal transmission distance is, the less the interference. So it is needed to shorten the cable length according to actual need and cut the excessive cable. The unamplified signals from the transducer to signal converter may be easily interfered during transmission, so care must be taken to connect wires and the shielding layer shall be grounded reliably at the same place where the power is grounded. After grounding, the cable shall be fixed and better in the special cable trunk (Figure 16).
Precaution
◆ Try to avoid vibration, and rubber the support or connect by the hose if necessary. ◆ If the pressure fluctuation occurs when there is no flow in a long pipe, a gate valve is needed to be installed before and after
the flowmeter.
◆ If water is contained in the steam or steam in water, a water separator shall be equipped.
◆ Installations for wafer type, flange connection and insertion type are separately as shown in Figure 17, 18 and 19.
Fig.17: Wafer type Fig.16: Remote type
13
Fig.19: Insertion type Fig.18: Flange connection
FISHERMETER
Contact us
Once a quotation inquiry is received, a regional sales representative will contact
you within 24 to 48 hours.
International Sales Department
Tel: +86-10-8483 3261
+86-10-8483 3671
Fax: +86-10-8482 9367
+86-10-8483 3673
E-mail:[email protected]
Technical Service
Tel; +86-10-8947 8461-605 / 606
+86-10-8947 8421-605 / 606
Fax: +86-10-8947 8461-607
+86-10-8947 8421-607
E-mail:[email protected]
Office Address
Beijing Fishermeter Instrument Co., Ltd.
Post Code: 100107
Room 1204, B Block Fortune Center, Tianlang Garden,
Beiyuan Road, Chaoyang District, Beijing, China. (100107)
http://www.fishermeter.com/english
Factory Address
1st building, Mauhwa Industry Park 1st block, Caida 3rd street, Caiyuan Industry Park,
Nancaizhen Town, Shunyi District, Beijing, China.
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FISHERMETER