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 Shanghai wechat Instrument Co., Ltd
Email: 2880151138@qq.com
Telephone: +86 182-2103-2874
Address: Room 402, building B, shuangshuanglou, 650 shenzhuan Road, Songjiang District, Shanghai Online consultation

Vortex Flowmeter

Cx-vfm-gb / E vortex flowmeter is widely used in petroleum, chemical, metallurgical, thermal, textile, papermaking and other industries for the measurement and control of superheated steam, saturated steam, compressed air and general gases (such as oxygen, nitrogen, hydrogen, natural gas, gas, etc.), water and liquid (such as water, gasoline, alcohol, benzene, etc.) in petroleum, chemical, metallurgical, thermal, textile and paper industries Set in body
Hotline: 182-2103-2874

Product introduction

Brief introduction of vortex flowmeter Technology

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Cx-vfm-gb / E vortex flowmeter is widely used in petroleum, chemical, metallurgical, thermal, textile, papermaking and other industries to measure and control superheated steam, saturated steam, compressed air and general gases (oxygen, nitrogen, hydrogen, natural gas, gas, etc.), water and liquid (such as water, gasoline, alcohol, benzene, etc.)

1、 How it works
If a non streamline vortex generator (blocking fluid) is set in the fluid, two rows of regular vortices will be generated alternately from both sides of the vortex generator. This kind of vortex is called Karman vortex street, as shown in Fig. (1).
  1.  Installation drawing of vortex flowmeter
Figure 1
Vortices are arranged asymmetrically downstream of the vortex generator. Suppose that the frequency of the vortex is f, the average velocity of the flow from the measured medium is V, the width of the upstream surface of the vortex generator is D and the path of the body is d. according to the principle of Karman vortex street, the relationship is as follows:

F = STV / D formula (1)
Where:
Frequency of Karman vortex generated on one side of f-generator
St Strouhal number (dimensionless number)
V - average velocity of fluid
The width of vortices
Therefore, the instantaneous flow can be calculated by measuring the separation frequency of Karman vortex street. The Strouhal number (st) is a dimensionless unknown number,
Figure 2 shows the relationship between Strouhal number (st) and Reynolds number (RE).
Overview
 diagram
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Figure 2
In the straight part with ST = 0.17 in the curve table, the release frequency of vortex is directly proportional to the flow velocity, which is the measurement range of vortex street flow sensor. As long as the frequency f is detected, the velocity of the fluid in the pipe can be obtained, and the volume flow can be obtained from the velocity v. The ratio of the measured pulse number to volume is called the instrument constant (k), as shown in equation (2)
K = n / Q (1 / m3) formula (2)
Where k = instrument constant (1 / m3).
N = number of pulses
Q = volume flow (M3)
1、 Main technical indexes (1)
Nominal diameter (mm) 25, 40, 50, 65, 80100125150200250300, (300-1000 plug-in)
Nominal pressure (MPA) Dn25-dn200 4.0 (> 4.0 agreement supply), dn250-dn300 1.6 (> 1.6 agreement supply)
Medium temperature (℃) Piezoelectric type: - 40 ~ 260, - 40 ~ 320; capacitive type: - 40 ~ 300, - 40 ~ 400, - 40 ~ 450 (order by agreement)
Body material 1Cr18Ni9Ti (other materials supplied by agreement)
Allowable vibration acceleration Piezoelectric: 0.2g capacitive: 1.0-2.0g
accuracy 5% R, ± 1FS; plug-in type: ± 2.5% R, ± 2.5% FS
Range degree 1:6~1:30
Supply voltage The sensor is + 12V DC, + 24 V DC; the transmitter is + 12V DC, + 24 V DC; the battery powered type is 3.6V battery
output signal Square wave pulse (excluding battery powered): high level ≥ 5V, low level ≤ 1V; current: 4 ~ 20mA
Pressure loss coefficient According to JB / t9249, CD ≤ 2.4
Explosion proof sign Intrinsic safety type: Exd Ⅱ IA ct2-t5 flameproof type: Exd Ⅱ ct2-t5
Protection level Common IP65 diving IP68
environment condition Temperature - 20 ℃ - 55 ℃, relative humidity 5% - 90%, atmospheric pressure 86 - 106 kPa
Applicable media Gas, liquid, steam
transmission distance Three wire pulse output type: ≤ 300m, two wire standard current output type (4 ~ 20mA): load resistance ≤ 750 Ω

Table 2 flow range of vortex flow sensor under reference condition
Instrument diameter
(mm)
liquid Gas
measuring range
(m3/h)
Output frequency range
(Hz)
measuring range
(m3/h)
Output frequency range
(Hz)
twenty-five 1.2~16 25~336
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8.8~55 190~1140
forty 2~40 10~200 27~205 140~1040
fifty 3~60 8~160 35~380 94~1020
eighty 6.5~130 4.1~82 86~1100 55~690
one hundred 15~220 4.7~69 133~1700 42~536
one hundred and fifty 30~450 2.8~43 347~4000 33~380
two hundred 45~800 2~31 560~8000 22~315
two hundred and fifty 65~1250 1.5~25 890~11000 18~221
three hundred 95~2000 1.2~24 1360~18000 16~213
(300) 100~1500 5.5~87
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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: the diameters of (300) ~ (1000) in the table are plug-in type
Table (3) standard state density of common gas medium (0 ℃, absolute pressure P = 0.1MPa)
Gas name Density (kg / m3) Gas name Density (kg / m3)
Air (dry) one point two nine two eight acetylene one point one seven one seven
nitrogen one point two five zero six ethylene one point two six zero four
oxygen one point four two eight nine propylene one point nine one four zero
argon one point seven eight four zero methane zero point seven one six seven
neon zero point nine zero zero zero ethane one point three five six seven
ammonia zero point seven seven one zero propane two point zero zero five zero
hydrogen zero point zero eight nine eight eight butane two point seven zero three zero
carbon monoxide one point nine seven seven zero four natural gas zero point eight two eight zero
carbon dioxide one point three four zero one Coal to gas zero point eight zero two zero
(1) Installation dimensions of instrument: see Fig. (5) and Fig. (6)
? Flange type vortex flowmeter ??
Diameter (mm)
(mm)
A B C CH
15~25 seventy fifty-five three hundred and ninety four hundred and fifty-five
forty eighty-five
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eighty three hundred and eighty-five four hundred and forty
fifty eighty-five ninety three hundred and ninety four hundred and fifty
sixty-five eighty-five one hundred and five four hundred four hundred and seventy
eighty ninety one hundred and twenty four hundred and twenty four hundred and eighty
one hundred eighty-five one hundred and forty four hundred and forty five hundred
one hundred and twenty-five ninety-five one hundred and sixty-eight four hundred and sixty-five five hundred and thirty
one hundred and fifty one hundred one hundred and ninety-four four hundred and ninety five hundred and sixty
two hundred one hundred and two two hundred and forty-eight five hundred and forty-five six hundred and ten
two hundred and fifty one hundred and fifteen three hundred six hundred six hundred and sixty
three hundred one hundred and thirty three hundred and fifty six hundred and fifty seven hundred and ten
 Plug in vortex flowmeter







caliber
(mm)
DN250 DN300 DN400 DN500 DN600 DN800-
two thousand
L sixty point five fifty-eight sixty-five point five sixty point five fifty-five point five forty-five point five