Precession vortex flowmeter

The precession vortex flowmeter integrates flow temperature and pressure detection functions and can automatically compensate for temperature, pressure and compression factors. It is an ideal instrument for gas measurement in petrochemical, power, metallurgy and other industries.
Features of the product of a precession vortex flowmeter
No mechanical movable parts, not easy to corrode, stable and reliable, long life, no special maintenance required for long-term operation
Adopt a computer chip with high integration, small size, good performance and complete functions Strong
The intelligent flow meter integrates the flow probe, microprocessor, pressure and temperature sensor into one body and adopts a built-in combination to make the structure more compact. It can directly measure the flow pressure and temperature of the fluid and automatically track compensation and compression factor correction in real time
The use of dual detection technology can effectively improve the detection signal strength and suppress the interference caused by pipeline vibration
The use of domestic leading intelligent anti-seismic technology can effectively suppress the interference signals caused by vibration and pressure fluctuation
The use of Chinese character lattice The display screen displays multiple digits, the reading is intuitive and convenient, and can directly display the volume flow rate under working conditions, the total volume flow rate under standard conditions, and parameters such as medium pressure and temperature. One year of historical data
The converter can output frequency pulses to analog signals and has an interface that can be directly connected to the microcomputer network for transmission distances up to
Multiple physical parameters alarm output can be selected by the user
The flow meter head can be rotated and is easy to install and use
With the company's data collector, remote data transmission can be carried out through the Internet or telephone network
The pressure and temperature signals are sensor input methods with strong interchangeability
/> The whole machine has low power consumption and can be powered by internal battery or external power supply.
Working principle of two-precession vortex flowmeter
The flow profile of the flow sensor is similar to the profile of a Venturi tube (as shown in the figure). A set of spiral guide vanes is placed on the inlet side. When the fluid enters the flow sensor, the guide vanes force the fluid to produce a violent vortex flow. When the fluid enters the diffusion section, the vortex flow is affected by the backflow and begins to rotate twice, forming a gyroscopic vortex precession phenomenon. The precession frequency is proportional to the flow rate and is not affected by the physical properties and density of the fluid. The detection element can obtain good linearity within a wide flow range by measuring the secondary rotational precession frequency of the fluid. The signal is amplified, filtered and shaped by the preamplifier and converted into a pulse signal proportional to the flow rate. Then, together with detection signals such as temperature and pressure, it is sent to the microprocessor for integration processing. Finally, the measurement results are displayed on the LCD screen (instantaneous flow accumulation flow and temperature pressure data).
The main purpose of the three-precession vortex flowmeter
Vortex generator
A spiral blade made of aluminum alloy with a certain angle is fixed on the front of the contraction section of the casing to force the fluid to produce a strong vortex flow. .
Shell
The fluid channel itself has a flange and a certain shape. The shell material can be cast aluminum alloy or stainless steel according to different working pressures.
Intelligent flow meter totalizer
It is composed of temperature and pressure detection analog channel, flow detection digital channel, microprocessing unit liquid crystal drive circuit and other auxiliary circuits, and is equipped with an external signal interface.
Temperature sensor
Platinum resistor is used as the temperature sensitive element, and its resistance value corresponds to the temperature within a certain temperature range.
Pressure sensor
The piezoresistive diffused silicon bridge is used as the sensitive element. The bridge arm resistance will change as expected under the action of external pressure. Therefore, under the action of a certain excitation current, the potential difference between its two output terminals is different from that of the outside world. Directly proportional to pressure.
Piezoelectric crystal sensor
Installed near the throat of the expansion section of the shell, it can detect the frequency signal of vortex precession.
Decycler
Fixed at the outlet section of the housing, its function is to eliminate the vortex flow to reduce the impact on the performance of downstream instruments.
Precautions for installation and maintenance of precession vortex flowmeter
Any type of metering instrument has its particularity. The intelligent precession vortex flowmeter is no exception. In order to allow this instrument to better serve the flow measurement work, practical experience from the production site shows that the following aspects of attention should be paid enough attention by the relevant management and use departments.
① Pay attention to instrument selection. After the intelligent precession vortex flowmeter has been selected, the next step is to select the instrument specifications and its supporting components. Only when you choose a sentence well can you use it well. For this reason, two basic principles should be grasped during the selection process, namely, one must ensure the accuracy of use and the other must ensure production safety. To achieve this, it is necessary to implement three selection parameters: the maximum, minimum and common instantaneous flow rates in the near and long term (mainly used for the size and specification of the selected instrument) and the design pressure of the measured medium (mainly used for the selected instrument). Nominal pressure level) working pressure (mainly used for the pressure level of selected instrument pressure sensors).
② Perform pre-use calibration on the one hand because there are still various difficulties in on-site verification of precession vortex flowmeters. In addition, if the purpose of purchase is to use this instrument in more important measurement situations, such as large-flow trade measurement or measurement points with prominent measurement disputes, and the application site does not have the conditions for online flow calibration, then in this case It would be too early to easily judge that all the performance of the watch is qualified based only on the factory certificate provided by the manufacturer at the time of purchase. Therefore, in order to ensure the reliability and accuracy of the measurement results of the instrument in the future work process, it is necessary to send it to a department with verification capabilities and qualifications in this area for a system verification within the full flow range before formal installation.
③ Do a good job in process installation. Although the precession vortex flowmeter does not have many special requirements for process installation and use environment, any type of flow measurement instrument has such a commonality, which is to avoid vibration and high temperature environment as much as possible. Flow interference components (such as compressor separator, pressure regulating valve and header elbows, etc.) keep the inner wall of the straight pipe section before and after the instrument smooth and straight to ensure that the measured medium is a clean single-phase fluid.
④ Strengthen later management Although the precession vortex flowmeter has a variety of automatic processing functions and micro-power consumption characteristics, it still needs to be strengthened after it is put into operation. For example, in order to ensure the accuracy and reliability of the long-term operation of the instrument (to avoid unexpected outages and data loss), the system calibration should be carried out regularly (every ~ year), the header data should be copied (daily or weekly), and the media parameters should be replaced (monthly or every week). Quarterly) and check the battery condition from time to time to check the instrument coefficient and lead seal, etc.
⑤ Pay attention to internal maintenance. If the measuring chamber and its components of the meter need to be regularly inspected or cleaned due to dirty air or other reasons, special attention must be paid to the vortex generation of precession vortex flowmeters of the same specifications. Core components such as body fluids cannot be interchanged, otherwise the instrument measurement coefficients must be recalibrated and the temperature and pressure sensors equipped with them must be systematically calibrated.