Piezoelectric / capacitance type CSS-VFM- GB / E Vortex Flow Meter
1.Summary
GB / E type vortex flow meter is widely used in petroleum, chemical, metallurgical, power, textile, paper and other industries on the superheated steam, saturated steam, compressed air and gases
( oxygen, nitrogen and hydrogen, natural gas, gas ), water and liquid ( such as: water, gasoline, alcohol, benzene and so on ) measurement and control
2. Working principle
To install a vortex generator(bluff body)in the fluid,which can produces regular vortex at both sides of the vortex generator altematively.Such vortex is called Karman Vortex.Vortex trains are asymmetrically arranged at the downstream of the vortex geberator. Suppose the generating frequency of the vortex is f,the average speed of the incoming flow of the tested medium is V,the head-on width of the vortex generator is d,and the diameter of the flowmeter is D,and base on the principles of Karman Vortex,the following relations will be obtained:
Note:f- Suppose the generating frequency of the vortex
St -Strouhal number
V -average flow velocity at both sides of the vortex generator d- the vortex geberator body width
Thus, by measuring the Carmen frequency of vortex separation of instantaneous flow rate can be calculated. Among them, Strouhal number ( St ) is a dimensionless unknown, Figure ( two) said the Strouhal number ( St ) and Reynolds number ( Re ) relationship.
In the curve St = 0.17straight section, whirlpool release frequency and velocity proportional to, namely the vortex flow sensor measurement range. As long as the detected frequency f can be obtained within the tube by the flow rate of the fluid, flow velocity and volume flow rate V. The measured pulse number and volume ratio, called the instrument constant ( K ), see type (2)
K＝N/Q（1/m3） Formula (2)
K＝Instrument constant（1/m³）
N＝Pulse number
Q＝Volume flow （m³）
3．Main technical index Unit(1)
|
Nominal diameter(mm)
|
25，40，50，65，80，100，125，150，200，250，300，(300～1000 Insert type)
|
|
Nominal pressure (MPa)
|
DN25-DN200 4.0(>4.0 Supply agreement)，DN250-DN300 1.6(>1.6
Supply agreement)
|
|
Medium temperature(℃)
|
Piezoelectric type：-40～260，-40～320；Capacitance type:-40～300, -40～400，-40～450（Supply agreement）
|
|
Body material
|
1Cr18Ni9Ti,(Other materials supply agreement)
|
|
Allowable vibration
acceleration
|
Piezoelectric type:0.2g Capacitance type:1.0 2.0g
|
|
Accuracy
|
±1%R，±1.5%R，±1FS；Insert type：±2.5%R，±2.5%FS
|
|
Range of
|
1 : 6 ~1: 30
|
|
Power supply voltage
|
Sensor +12V DC +24V DC Transmitter +12V DC +24V DC
Battery type 3.6V Battery
|
|
Output signal
|
Square wave pulse ( not including the battery power supply
type ): high level or low level5V,1V; current: 4~ 20mA
|
|
Pressure loss
coefficient
|
In line with the JB / T9249standard Cd = 2.4
|
|
Explosion proof marks
|
Intrinsic safety type: Exd IA CT2-T5 flameproof type: Exd
CT2-T5
|
|
Protection grade
|
The ordinary IP65 diving type IP68
|
|
Environmental
conditions
|
Temperature - 20~ 55,5% ~ 90% of relative humidity,
atmospheric pressure is 86 ~ 106kPa
|
|
Applicable medium
|
Gas, liquid, steam
|
|
Transmission distance
|
Three wire system pulse output type: < 300m, two line
standard current output type (4 ~ 20mA ): load resistance
less than 750ohm
|
|
|
|
Reference conditions of vortex flow sensors flow rate range table
|
Meter diameter
|
Liquid
|
|
Gas
|
|
|
Measuring range
|
Output frequency
|
Measuring range
|
Output frequency
|
|
|
(mm)
|
|
|
(m 3/h )
|
range(Hz)
|
(m 3/h )
|
range(Hz)
|
|
|
|
|
|
25
|
1.2～16
|
425～336
|
8.8～55
|
190～1140
|
|
|
40
|
2～40
|
10～200
|
27～205
|
140～1040
|
|
|
50
|
3～60
|
8～160
|
35～380
|
94～1020
|
|
|
80
|
6.5～130
|
4.1～82
|
86～1100
|
55～690
|
|
|
100
|
15～220
|
4.7～69
|
133～1700
|
42～536
|
|
|
150
|
30～450
|
2.8～43
|
347～4000
|
33～380
|
|
|
200
|
45～800
|
2～31
|
560～8000
|
22～315
|
|
|
250
|
65～1250
|
1.5～25
|
890～11000
|
18～221
|
|
|
300
|
95～2000
|
1.2～24
|
1360～18000
|
16～213
|
|
|
(300)
|
100～1500
|
5.5～87
|
1560～15600
|
85～880
|
|
|
(400)
|
180～3000
|
5.6～87
|
2750～27000
|
85～880
|
|
|
(500)
|
300～4500
|
5.6～88
|
4300～43000
|
85～880
|
|
|
(600)
|
450～6500
|
5.7～89
|
6100～61000
|
85～880
|
|
|
(800)
|
750～10000
|
5.7～88
|
11000～110000
|
85～880
|
|
|
(1000)
|
1200～1700
|
5.8～88
|
17000～170000
|
85～880
|
|
|
>(1000)
|
Agreement
|
|
Agreement
|
|
|
Note: (300) to (1000) diameter for insertion type
Commonly used gas standard density (0 degrees C, absolute pressure P =0.1MPa )
|
Gas name
|
Density (kg/m3)
|
Gas name
|
Density (kg/m3)
|
|
Air ( dry)
|
1.2928
|
Acetylene
|
1.1717
|
|
Nitrogen
|
1.2506
|
Ethylene
|
1.2604
|
|
Oxygen
|
1.4289
|
Propylene
|
1.9140
|
|
Argon
|
1.7840
|
Methane
|
0.7167
|
|
Neon
|
0.9000
|
Ethane
|
1.3567
|
|
Ammonia
|
0.7710
|
Propane
|
2.0050
|
|
Hydrogen
|
0.08988
|
Butane
|
2.7030
|
|
Carbon monoxide
|
1.97704
|
Natural gas
|
0.8280
|
|
Carbon dioxide
|
1.3401
|
Coal gas
|
0.8020
|
