Coriolis mass flowmeter
As shown in Fig. 1, when a particle of mass m moves in a pipe with angular velocity rotating on the P axis, the particle is accelerated by two components and its forceA. Normal acceleration is centripetal acceleration alpha r, whose magnitude is equal to_2r, and its direction is toward P axis; B. Tangential acceleration alpha t is Coriolis acceleration, whose magnitude is equal to 2_, and its direction is perpendicular to alpha R.Because of the compound motion, Coriolis Fc = 2_m is acted in the alpha t direction of the particle, and a force - Fc= - 2_m is acted on the particle by the pipeline. When a fluid with a density of Rho flows at a constant velocity in a rotating pipe, any length x pipe will be subjected to a tangential Coriolis force of Fc.
△FC=2ωpA△
Formula A - the flow area of the pipeline. Because the mass flowmeter flow rate is δm，δm=ρυA, so
Therefore, direct or indirect measurement of Coriolis force produced by flow fluid in rotating pipes can measure mass flow, which is the basic principle of Coriolis mass flowmeter.
However, it is difficult to generate Coriolis force by rotating motion. At present, products are replaced by pipeline vibration, that is, a thin-walled measuring tube fixed at two broken ends, which is stimulated by the resonance or near resonance frequency of the measuring tube at the midpoint. The fluid flowing in the tube generates Coriolis force, which makes the two halves of the measuring tube deflect in opposite directions, and is checked by electromagnetic method.Measure the deflection to get the mass flow rate.
Because the fluid density will affect the vibration frequency of the measuring tube, and the density has a fixed relationship with the frequency, so the mass flowmeter can also measure the fluid density.
|
Nominal diameter DN (mm) |
Maximum flow value (t / h) |
Maximum working pressure (Mpa) |
Zero stability kg / h |
|
1 |
0.05 |
4 |
0.01 |
|
3 |
0.2 |
4 |
0.04 |
|
6 |
0.5 |
4 |
0.1 |
|
8/10 |
1 |
4 |
0.15 |
|
15 |
3 |
4 |
0.4 |
|
25 |
6 |
4 |
0.6 |
|
40 |
16 |
4 |
1 |
|
50 |
30 |
4 |
3 |
|
80 |
60 |
2.5 |
10 |
|
100 |
100 |
2.5 |
20 |
|
150 |
200 |
2.5 |
30 |
|
200 |
400 |
2.5 |
6 |
|
Measured medium |
Liquids, gases |
|
Measuring diameter |
1mm~300mm |
|
Measurement items |
Mass Flow, Density, Temperature, Volume Flow,% Concentration |
|
Density measurement range |
0.2g/cm 3~2.5g/cm 3 |
|
Medium temperature |
-200Temperature ~+300 |
|
Flow measurement error |
Liquid 0.2% R + Cz, 0.15% R + Cz, gas 0.5% R + Cz, 1.0% R + Cz, |
|
Density measurement error |
0.002g/cm3 |
|
Temperature measurement error |
Less than 1 degrees centigrade |
|
Signal form |
4~20mA, O~2kHZ, RS485, Hart |
|
Power supply |
24VDC |
|
Measuring tube material |
304316, can also be provided by negotiation according to user’s request |
|
Explosion proof grade |
Exd (ib) IICT4, Exd IICT4 |
|
Shell protection grade |
IP67 |
|
Flange standard |
GB/T series of national standards can also be processed according to user requirements. |
According to the nominal diameter of the pipe, the product specifications can be divided into: DN1, DN2, DN3, DN6, DN10, DN15, DN25, DN40, DN50, DN80, DN100, DN150 (unit: mm).
a. The flange specifications of the flow meter implement the relevant technical parameters, technical conditions and types specified in the GB / T series standards. Can also be processed according to customer requirements;
b. In the selection of flowmeters, the user should indicate the requirements of the required flowmeters in accordance with the format of the model description;
c. If the user needs to use the caliber, nominal pressure and output form other than this model description, please explain;
d. When selecting a high-temperature type flowmeter, in addition to filling in according to the model description format, the maximum working temperature of the measured medium should be specified;
f. The user needs a special measuring tube material, which should be explained.
|
|
Diameter (mm) |
A |
A1 |
B |
B1 |
Weight (kg) |
|
1/3/6/8 |
210 |
290 |
330 |
460 |
7 |
|
|
10 |
230 |
320 |
440 |
560 |
9 |
|
|
15 |
250 |
350 |
460 |
580 |
11 |
|
|
25 |
300 |
380 |
610 |
730 |
17 |
|
|
40 |
320 |
450 |
660 |
780 |
23 |
|
|
50 |
380 |
530 |
720 |
840 |
28.5 |
|
|
80 |
520 |
700 |
850 |
980 |
43 |
|
|
100 |
590 |
770 |
1010 |
1130 |
63 |
|
|
150 |
700 |
850 |
1300 |
1420 |
75 |
|
|
200 |
1050 |
1210 |
1410 |
1530 |
100 |
a. Flange connection: GB / T series of national standard, HG series of chemical industry, JB / T series of machinery, and flanges according to customer requirements can also be negotiated. Nominal pressure 0.6MPa ~ 42MPa.
b. Thread connection (diameter below DN15).
 |
 |
|
Horizontal pipes:
With the main body facing down,Measuring liquid |
|
 |
|
|
Horizontal pipes:
The main body is facing up, self-draining, measuring the slurry containing solids |
Vertical pipes:
Flag installation, self-draining, measuring liquid or slurry, liquid must flow from bottom to top |
