JGLU gas vortex flowmeter series is mainly used for medium
industrial pipe fluid flow measurement of steam, steam vortex
flowmeter features low pressure loss, measuring range, high
precision in the measurement conditions are not nearly the volume
density of the fluid flow , Pressure, temperature, viscosity and
other parameters. No moving mechanical parts, so high reliability and little
maintenance. Long-term stability of the instrument parameters. Gas
flowmeter using piezoelectric stress sensors, high reliability, can
be -20~ +250operating temperature range. With analog standard
signal, but also digital pulse signal output, easily supporting the
use of computers and other digital systems is a more advanced and
ideal flow meter 1、Works
Triangle set in the steam flow cylindrical bluff body, alternately
from both sides of the bluff body to generate a regular vortex,
this vortex is called Carmen vortex, as shown, the vortex
downstream of the bluff body listed in the non-symmetrically Order
The occurrence frequency of the vortex set f, the average flow rate
of the measured medium, the bluff body surface facing the flow
width d, the body of the path to D, you can get the following
relation： f=SrU1/d=SrU/md1）
Where U1 - the average velocity on both sides of the bluff bodym/s
Sr--Strouhal number
m--Segment Area on both sides of the bluff body and the pipe
cross-sectional area ratio
Pipe volume flowqv
qv=D2U/4=D2mdf/4Sr(2)
K=f/qv=[D2md/4Sr]-1(3)
Where K - the instrument flow coefficient, the number of pulses /
m3（P/m3）
K addition to the bluff body, the relevant geometry of the
pipeline, but also with the Strouhal number related. Strouhal
number of dimensionless parameters, it is with the bluff body shape
and Reynolds number on Figure 2 shows the cylindrical bluff body of
the Strouhal number and the pipe Reynolds number diagram. The
figure shows that in ReD = 2104 ~ 7106 range, Sr can be considered
as a constant, which is the normal operating range instrument. When
the measurement of gas flow, VSF formula for the flow meter
(4)
Figure 2 Relationship between Strouhal number and Reynolds number
curve
Where qVn, qV - were under standard conditions (0oC or 20oC,
101.325kPa) and the volume of traffic conditionsm3/h
PnP--Respectively, under standard conditions and conditions for the
absolute pressurePa
TnT--Respectively, under standard conditions and conditions of the
thermodynamic temperatureK
ZnZ--Respectively, under standard conditions and conditions for the
gas compressibility
Can be seen from the above equation, VSF output pulse frequency
signal from fluid properties and composition changes, that
instrument coefficient in a certain Reynolds number range, and only
with the bluff body shape and size of the pipe and so on. But as
the material balance and energy flow in the measurement of mass
flow to be detected, then the flow meter should also monitor the
volume of the output signal flow and fluid density, fluid
properties and composition of the flow measurement or have a direct
impact Gas flowmeter is based on the vortex principle Carmen Measurement
of fluid flow in closed conduits new flow meter. Media because of
its good ability to adapt, without direct measurement of
temperature and pressure compensation can be steam, air, gas,
water, liquid volume flow conditions, with temperature and pressure
sensor measures the standard volume flow and mass flow conditions,
is to cut expenditure Flowmeter ideal alternative
To improve the high temperature gas flowmeter and anti-vibration
performance, the company recently developed a JGLUG improved vortex
flow sensors, because of its unique structure and selection of
materials so that the sensor at high temperature (350 ℃), high
vibration (≤ 1g) use of harsh conditions
In practice, the maximum flow rate is often much lower than the
upper limit of the instrument, as the load changes, the minimum
flow rate and often lower than the lower limit of the instrument,
meters are not working in its optimum operating segment, in order
to solve this problem , commonly used in the measurement at the
reduced diameter to improve the measurement at the flow rate, and
smaller-diameter instrument to facilitate selection of the
measurement instrument, but this must be adjustable means between
adjustable tube and instrument over a length of straight pipe
section 15D to Rectifier, the processing, installation is not easy.
Our company has developed a vertical section of the shape of arc
rectifier LGZ adjustable, with a rectifier to improve the flow and
velocity distribution change multiple roles, its structure, small
size, process tube diameter of only 1 / 3, one made with the vortex
flowmeter Not only do not need to add another section of straight
pipe, you can also reduce the process tube |
