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Metal rota high pressure air flow meters for oil and high pressure gas Pipe size DN15-100
Work principle
The metal flowmeter's flow sensing element consists of a vertical tapered tube expanding from bottom to top and a float set moving up and down along the tapered tube axis. Working principle shown in Figure 1, the measured fluid from the bottom up through the conical tube 1 and the float 2 formed ring gap 3, the upper and lower ends of the float to produce differential pressure to form the floating force of the float when the lift is greater than the submerged fluid The weight of the float, the float will rise, the ring gap area increases, the annular gap at the immediate decline in fluid flow velocity, the float lower differential pressure decreases, the role of the buoy lift force also decreases until the lifting force is equal to immersed in the fluid In the float weight, the float will be stable at a certain height. The height of the float in the conical tube and the flow through the corresponding relationship.
The basic equation of volume flow Q is:
When the float is non-solid hollow structure (put the weight adjustment), then
Where α - instrument flow coefficient, due to float shape varies;
ε - gas expansion coefficient measured gas is gas, usually due to
the small coefficient of this correction is ignored, and has been
included in the flow coefficient through the calibration, such as
liquid, then ε = 1;
△ F - Circulation area, m2;
g - local acceleration of gravity, m / s2;
Vf - float volume, if extended body should also include, m3;
ρf - float material density, kg / m3;
ρ - measured fluid density, such as gas is the density of the
upstream cross-section of the float, kg / m3;
Ff - working area of the float (maximum diameter) cross-sectional
area, m2;
Gf - float quality, kg.
Circulation area and the relationship between the height of the
float as shown in equation (3), when the structural design has been
set, then d, β are constant. There is a quadratic term in h, we can
not ignore this nonlinear relationship. Only when the cone angle is
small, can we regard it as approximate linearity.
m2 (3)
Where d - maximum diameter of the float (ie, working diameter), m;
h - float from the cone diameter equal to the maximum diameter of
the float rise height, m;
β - taper cone angle;
a, b - constant.
Data sheet
Diameter(mm) | Flow range | Pressure loss | |||
Anticorrosion | Normal | air(m3/h at 0.1013Mpa) | water L/h | air | water |
15 | 15 | 0.07-0.7 | 2.5-25 | 7.1 | 6.5 |
0.11-1.1 | 4.0-40 | 7.2 | 6.5 | ||
0.18-1.8 | 6.3-63 | 7.3 | 6.6 | ||
0.28-2.8 | 10-100 | 7.5 | 6.6 | ||
0.4-4.0 | 16-160 | 8.0 | 6.8 | ||
0.7-7.0 | 25-250 | 10.8 | 7.2 | ||
1.0-10 | 40-400 | 10 | 8.6 | ||
25 | 1.6-16 | 63-630 | 14 | 11.1 | |
25 | 3.0-30 | 100-1000 | 7.7 | 7 | |
4.5-45 | 160-1600 | 8.8 | 8 | ||
7.0-70 | 250-2500 | 12 | 10.8 | ||
50 | 11-110 | 400-4000 | 19 | 15.8 | |
50 | 18-180 | 630-6300 | 8.6 | 8.1 | |
25-250 | 1000-10000 | 10.4 | 11 | ||
80 | 40-400 | 1600-16000 | 15.5 | 17 | |
80 | 60-600 | 2500-25000 | 8.0 | 8.1 | |
100 | 100-1000 | 4000-40000 | 13.0 | 9.5 | |
100 | 200-2000 | 6300-63000 | 11.0 | 10 |