是高精度传感器，能在相当复杂的工况下正常工作，并保持良好的性能。 Annubar flowmeter is a high-precision sensor, which can work normally under quite complicated working conditions and maintain good performance. In order to achieve the best performance, the flowmeter needs to be reasonably installed and maintained. When selecting this product, the inner diameter of the measuring tube must be provided accurately. Because the distribution of the pressure holes of the designed probe is calculated according to the center of the pipe, if there is a large error in the inner diameter of the pipe, it will cause the probe to be different from the measured pipe and cause a large measurement error. As a flow meter for measurement, it is recommended to use a probe with a full pipe insertion, especially when the straight pipe section does not meet the requirements. Annubar flowmeter replaces the cross-sectional flow velocity of the orifice plate by measuring the flow velocity on a certain diameter, and the flow velocity on different diameter lines is not exactly the same (unless the straight pipe section where it is located is long enough), so if the installation position and Improper orientation will lead to invalid measurement or inaccurate measurement. Therefore, when selecting the type, theoretical analysis and calculation should be performed according to the installation conditions, and the appropriate installation position and installation method should be selected to achieve the best results. Flowmeter probe installation is recommended to be installed under the guidance of the manufacturer to prevent large measurement errors due to probe installation
的差压式检测杆上各取压孔处的流速是不同的，各取压孔之间存在一定的压力差，这样，各取压孔之间就有介质流动，流动介质中的杂物就会产生埋积，形成堵塞，时间一长就会造成差压损失。 The flow velocity at the pressure-receiving holes on the differential pressure detection rod of the Annubar flowmeter is different. There is a certain pressure difference between the pressure-receiving holes. In this way, the medium flows between the pressure-receiving holes and the flowing medium. The debris in the medium will bury and form a blockage, which will cause differential pressure loss over time. At present, although the Annuba manufacturing plant claims that the problem of anti-clogging of the measurement sensor can be solved, due to the special circumstances of each production process, the author still recommends the installation of necessary auxiliary equipment such as debris filtering devices to ensure the normal operation of the instrument (may Negotiate with the supplier for specific practices). 2. From the basic formula of flow rate, as long as the output differential pressure ΔP of the detection rod is effectively measured, the flow rate of the fluid can be measured. For a long time, the detection rod back pressure detection hole has only used one measurement hole. It is believed that the detection rod detection hole is already in the potential flow according to the requirements of the specification. The premise of the potential flow is that the static pressure at each point on the cross section of the pipeline is equal. There is no lateral flow, and from this perspective, a back pressure detection hole is sufficient. In order to prevent the flow of fluid from blocking the back pressure detection hole during the detection process, porous back pressure can be used to take pressure, which has begun to be applied to the detection rod flow sensor. 3. The flow coefficient K is unstable, resulting in unstable flow. For a detection rod with a circular cross section, when the Reynolds number Re is between 105 and 106, the flow coefficient K is unstable, and its stable region is at Reynolds numbers Re <105 and Re> 106. This is mainly due to the existence of a "resistance crisis" in the resistance member with a circular cross section. Due to the different separation points of the fluid flowing through the circular tube, the pressure distribution caused by the circular tube when it is flowing into the tube is different, which causes the change of the flow coefficient K. A rhombus-shaped detection rod can overcome the unstable area of a circular cross-section. Regardless of the value of the Reynolds number of the rhombic cross section, its separation point is fixed and unchanged, which better solves the difficulty of the unstable area of the detection rod flow sensor when detecting the flow of liquid and gas (vapor). 4. Annuba flowmeter is based on the principle of pitot tube speed measurement, and calculates the flow rate by measuring the total static pressure. It is often used for the measurement of liquid and gas (vapor) body flow in large-caliber pipes. The differential pressure it generates is generally small, and the minimum may be only 20Pa ～ 30Pa. For this reason, it is necessary to avoid using long impulse tubes, and choose high precision micro differential pressure transmitters, such as Honeywell, EJA differential pressure transmitters, etc. The best solution is to use a detection rod, The direct installation of the three-valve and differential pressure transmitter integration, such as the LG-A series integrated intelligent Annubar flowmeter, can not only reduce the leakage caused by the use of the impulse tube, but also compensate the temperature and pressure. The distortion of the differential pressure signal varies due to changes in the signal.
（均速管流量计）测量范围广泛，适用于大部分现场介质的测量。 Annubar flowmeter (average speed tube flowmeter) has a wide measurement range and is suitable for the measurement of most on-site media. Is a recognized energy-saving flow meter. Today, I will give you a detailed summary of the common installation method of Annubar flowmeters. For production enterprises, we all know that the direct installation (that is, welding) connection method of Annubar flowmeters is normally used for field installation. 1. The first premise of installation is to confirm whether the on-site straight pipe section meets the requirements. For specific requirements, refer to the relevant manual or consult the technical department of the company, and then determine the installation direction of the flow meter according to the direction of the on-site fluid. 2. After the direction is determined, use the hole opener to make holes in the pipe (conventional opening size is 25mm) a, single-sided support; that is, make a hole in the pipe according to the size of the Annubar sensor. The installation method is suitable for on-site pipelines with a diameter of less than 600mm, because in a small-aperture installation method, this installation method is sufficient to ensure the stability of the sensor itself and the measurement accuracy. b; double-sided support; after determining the installation direction, open two holes of the same size in the symmetrical position on the pipe, which is opposite to the single-sided support above, that is, for the measurement of large diameter, in order to ensure the stability of the sensor To install Annubar flowmeter, use double-sided fixing. 3. Insert Annubar flowmeter into the pipe, and fix the sensor in the correct position by spot welding, but the probe part is required to be in the entire pipe inner diameter and on the same centerline with the centerline.
4. Finally, the entire welding joint is completely welded, and the welding part is rust-proofed. For the on-site cement pipeline, for the convenience of on-site installation, the company will also provide a steel plate with the Annubar flowmeter at the same time. The steel plate and the on-site pipeline are bolted to each other.