V-cone flowmeter, also known as inner cone flowmeter, V-cone, and cone flowmeter, is a new type of differential pressure flowmeter with patented technology. It has the same basic principle as other types of differential pressure flowmeters and is based on sealed pipes. Based on the energy conservation principle and the unique design of the V-cone flowmeter, the flow measurement range is expanded, and some limitations of the traditional differential pressure flowmeter are avoided, resulting in better working performance. The V-cone flowmeter hangs a cone-shaped interceptor in the center of the pipe. The cone-shaped part blocks the flow of the medium and reshapes the flow rate curve. The measurement media includes water, steam, air, natural gas, nitrogen, coke oven gas and organic gases. Medium conditions can range from cryogenic temperatures to supercritical conditions. The maximum working temperature is 450℃, the maximum pressure is 25Mpa, the maximum measurable Reynolds number is 5*106, and the minimum Reynolds number is 8*103 or even lower. Generates full-scale differential pressure signals from a minimum of less than 0.1 kPa to a maximum of tens of kPa.
V-cone flow working principle:
V-cone flowmeter special equipment TS supervisory inspection certificate MA coal safety certificate mining is a differential pressure flow meter. So far, flow meters designed based on the differential pressure principle have been used for more than a hundred years. The principle of differential pressure is based on the principle of energy conversion in sealed pipes, which means that for stable fluids, the flow rate is proportional to the square root of the flow rate of the medium in the pipe. When the medium approaches the cone, its pressure is P1. When the medium passes through the interception area of the cone, the speed increases and the pressure decreases to P2. Both P1 and P2 are led to the differential pressure transmission through the pressure port of the cone flowmeter. On the device, when the flow rate changes, the differential pressure value between the two pressure ports of the cone flow meter will increase or decrease.
The calculation formula used by the V-cone flowmeter when calculating flow is the same as that of other differential pressure flowmeters, but the unique design of its intercepting element forces the medium in the center of the pipe to flow around the cone. Compared with other differential pressure flowmeters, this There are many advantages. We can understand the performance of the cone flow meter with the help of the ideal flow rate curve distribution diagram. The fluid in the pipeline is not subject to any interference or obstruction, which is what we call an ideal flow state. Its flow velocity is evenly distributed, the flow velocity near the pipe wall is almost zero, the flow velocity in the center of the pipe reaches the maximum, and the flow velocity near the pipe wall is almost Zero is caused by the friction of the pipe wall on the medium. Since the cone is suspended in the center of the pipeline, it is in direct contact with the high-speed zone of the fluid, forcing the fluid in the high-speed zone to mix with the fluid in the low-speed zone near the pipe wall to uniformize the flow rate. Therefore, even if the flow rate is very low, the cone flowmeter can still make the fluid continuously interact with the highest flow rate in the center of the pipe to generate the correct differential pressure.
In reality, the flow rate is difficult to distribute evenly, and any changes on the pipeline may affect the fluid, such as bay heads, valves, diameter reduction, expansion, pumps, tees, etc., while the cone flowmeter uses the cone to The upstream flow velocity distribution curve is reshaped to ensure measurement accuracy even under extremely harsh conditions.
V-cone flow characteristics:
Flowmeter accuracy: ±0.5%, ±1.0%, ±1.5%. The system accuracy must refer to the application conditions and the accuracy of the secondary table.
Good repeatability: better than ±0.1%
Range ratio: 10:1 under normal circumstances, it can be increased if necessary.
The requirements for straight pipe sections are low: a 0~3D straight pipe section in front of the flowmeter and a 0~1D straight pipe section behind the flowmeter can ensure measurement accuracy. Experiments have shown that the V-cone flowmeter can be close to a single elbow or a double elbow with different planes with little impact on accuracy.
Good long-term stability: The shape design of the cone ensures that the fluid flows through the cone in a gradual process without sudden changes. The β value can remain unchanged for a long time, and the instrument can be used for a long time without calibration.
Signal stability: All differential pressure flowmeters will have "signal fluctuations", which means that even if the fluid is very stable, the signal generated by the primary throttling element will fluctuate. For the orifice plate, the vortices formed behind the throttling member are relatively long, and these long vortices will produce high-amplitude, low-frequency fluctuation signals, which will interfere with the readings of the differential pressure gauge. The cone-shaped flow meter will form a small vortex downstream of it, producing low-amplitude, high-frequency fluctuation signals.
Small pressure loss: Since there is no protruding baffle, the permanent pressure loss of the cone flowmeter is 3/4 lower than that of the orifice plate.
No trapped dead space: The “purged” design of the cone has no dead space, so there is no accumulation of fluid debris, slag or impurities on the cone.
Mixer function: The vortex generated downstream of the V-cone flowmeter is a short vortex, which can mix the medium downstream. Therefore, while currently working as a flowmeter, the V-cone flowmeter can also be used for static stirring in many occasions. The device can quickly and fully stir the medium evenly.
V-cone flow applications:
Medium: coal gas, natural gas (including humidity below 5%), various hydrocarbons (including moist HC gas), various rare gases (hydrogen, helium, argon, oxygen, nitrogen, etc.), chlorine gas, wet chlorine Chemical gases, air (including air containing water, SiO2 particles and other suspended matter), flue gas, saturated steam (two-phase flow containing steam and water), superheated steam, water, etc.
Conditions: from cryogenic to supercritical state, maximum temperature up to 450℃, maximum pressure 25Mpa.
Calculation: Each cone flow meter is calculated using specialized software based on the properties, pressure and temperature of the fluid. Users can select the β value according to their own application conditions (component of the measured medium, temperature, pressure, pipe diameter, maximum flow rate, common flow rate, minimum flow rate, and maximum allowable pressure loss).
Maintenance: The cone flowmeter is maintenance-free and does not require regular maintenance and calibration.
Our main products are: Electromagnetic flowmeter, Energy meter, Vortex flowmeter, Pressure transmitters, Level gauge, Magnetic flap level gauge.
