Illustrate
AK-VFM vortex flow meter can be used for measuring gas,and it has price edge,and the temperature of gas can reach to -50-250C
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:
cart（1）
f=StV/d Formula (1)
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
chart（2）
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）
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 |
Table(2) reference conditions of vortex flow sensors flow rate range table
|
Meter diameter (mm) |
Liquid | Gas | ||
|
Measuring range (m3/h) |
Output frequency range(Hz) |
Measuring range (m3/h) |
Output frequency range(Hz) |
|
| 25 | 1.2～16 |
25～336 |
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 | ||
Vortex Flow Meter Selection Table
| Spectrum | Explain | ||||||||||
| LU | Vortex flow meter | ||||||||||
| G | Sensor | ||||||||||
| Detection mode | B | Piezoelectric sensor | |||||||||
| E | Capacitance type sensor | ||||||||||
| Connection mode | 1 | Only the full pipe type | Flange connection | ||||||||
| 2 | Only the full pipe type | The flange clamp type | |||||||||
| 3 | Only to insert type | Simple insertion type | |||||||||
| 4 | Only to insert type | Insertion type ball valve | |||||||||
| Measurement of medium | 2 | Liquid | |||||||||
| 3 | Gas | ||||||||||
| 4 | Steam | ||||||||||
| Nominal diameter |
02 … 30 |
|
DN25 … unit：mm DN300 |
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| The use of the environment | P | Ordinary type | |||||||||
| B | Explosion proof type | ||||||||||
| Output signal | 1 | Pulse output | |||||||||
| 2 | 4 ~ 20mA output current, liquid crystal display | ||||||||||
| 3 | RS-485 communication | ||||||||||
| 4 | Battery powered, with temperature, pressure compensation | ||||||||||
| 5 |
The temperature and pressure compensation for one, 4 ~ 20mA current output type |
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| 6 |
The temperature and pressure compensation integrated, battery power supply type |
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| Type description |
For example: LUGE2405-P2 full pipe type capacitive vortex flow meter, a flange clamp connection, medium for steam Instrument path for DN50, general 4~ 20mA output current signal |
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Sensor the nominal size of the code table
| Nominal diameter DN mm | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 |
| Tag number | 02 | 03 | 04 | 05 | 06 | 08 | 10 | 12 | 15 | 20 | 25 |
| Nominal diameter DN mm | 300 | 350 | 400 | 450 | 500 | 600 | 700 | 800 | 1000 | 1200 | 1500 |
| Tag number | 30 | 35 | 40 | 45 | 50 | 60 | 70 | 80 | A0 | A2 | A5 |
