DN200 electromagnetic flowmeter straight pipe section length is not enough and processing methods

DN200 electromagnetic flowmeter has no flow blocking parts in the measurement pipe, so there is no additional pressure loss. There are no moving parts in the measurement pipe, so the sensor has a long life. The sensor requires a short straight pipe section, which is easy to install and can measure forward and reverse. Directional flow can be measured with a submersible installation. It is widely used in the fields of chemical industry, steel, coal, environmental protection, water conservancy, pharmaceuticals, papermaking, food, machinery and public utilities. It can accurately measure various acids, alkalis, salt solutions, raw water, cooling water, sewage, coal slurry, ore slurry, etc. The volume flow rate of conductive fluids and solid-liquid two-phase bodies such as mud, cement slurry, pulp, syrup, liquid medicine and various beverages.

1. Concession method The so-called concession method is to make concessions to a certain indicator. This method is commonly used in product quality management. For example, in chemical production, the products flowing out from the end of the process cannot meet the first-class product indicators, but can meet the second-class product indicators, so they are stored as second-class products for sale instead of scrapping them, which is more cost-effective economically. . At the site where the electromagnetic flowmeter is used, if the length of the straight pipe section cannot meet the requirements anyway, and the flow measurement results are not used for trade settlement, but for general monitoring or process control, you can try to use the concession method.

2. Install a flow regulator. The flow regulator can be used to reduce the length of the upstream straight pipe section. Fitting experiments show that it can be used downstream of any upstream fitting. Currently, only two types of flow regulators are listed in the ISO5167 text: the 19-tube bundle flow straightener and the Zanker flow regulator plate. The flow regulators are listed in the standard with applicable throttling and obstruction types and specific installation. Location etc.

3. Select a suitable model for DN200 electromagnetic flowmeter. Since different types of flowmeters have very different requirements for the length of straight pipe sections, if the flowmeter originally selected requires a longer straight pipe section and cannot meet the requirements anyway, a straight pipe section should be selected instead. Models with lower pipe length requirements.

4. Evaluate the influence value When the length of the straight pipe section is not enough, the uncertainty of the electromagnetic flowmeter increases. This is due to the distortion of the velocity distribution in the pipeline, which makes the actual flow coefficient of the instrument inconsistent with the flow coefficient during factory calibration. If a set of flow meters with front and rear pipe sections are assembled according to the actual type of pipe fittings and length of straight pipe sections on site, placed on the flow standard device, the flow coefficient of the instrument is calibrated, and then used as a set, and this flow coefficient is used to calculate the flow rate, it is also This eliminates the impact of insufficient straight pipe length on the measurement results.