Issues to be noted during installation of sewage electromagnetic flowmeter

In production measurement in many industrial fields, electromagnetic flow meters are no strangers. It is one of the instruments favored by on-site users for measuring conductive liquids. It is very common to use electromagnetic flowmeters not only in the industrial field, but also in food, pharmaceutical, textile, papermaking, environmental protection and other fields. Therefore, some users will encounter a series of problems during the use of electromagnetic flowmeters, such as the inability to measure normally, large flow fluctuations, and unguaranteed accuracy.

Therefore, there will be some problems during the installation and use of the electromagnetic flowmeter, resulting in measurement problems. Most of the reasons are due to problems during the installation and debugging of the flowmeter. These are all is the key factor in failure.

1. On the upstream side of the flow meter, if there are valves, elbows, tee pumps and other spoilers, the front straight pipe section should be larger than 20DN

2. Install an electromagnetic flow meter Especially for flowmeters lined with PTFE, the bolts connecting the two flanges should be tightened evenly, otherwise the PTFE lining will be easily crushed, so use a torque wrench.

3. When stray current interference occurs in pipelines, space electromagnetic waves or large motor magnetic field interference, etc. Stray current interference in pipelines can usually be measured satisfactorily with good individual grounding protection. However, if there is strong stray current in the pipeline that cannot be overcome, measures must be taken to insulate the flow sensor from the pipeline. Space electromagnetic wave interference is generally introduced through signal cables and is usually protected by single-layer shielding.

4. Usually electromagnetic flowmeters also have protection level requirements. Usually the protection level of the integrated type is IP65 and the split type is IP68. If the customer has requirements for the instrument installation environment, the installation location is in an underground well or other In humid places, it is recommended that customers choose split type.

5. In order to avoid signal interference, the signal between the transmitter and the converter must be transmitted with shielded wires. It is not allowed to place the signal cable and the power line in parallel in the same cable steel pipe. The length of the signal cable is generally Must not exceed 30m.

6. In order to ensure that the measuring tube of the electromagnetic flow transmitter is filled with the measured medium, it is recommended to install it vertically with the flow direction from bottom to top. Especially for liquid-solid two-phase flow, it must be installed vertically. If only horizontal installation is allowed on site, the two electrodes must be on the same horizontal plane.

7. If the liquid being measured carries particles, such as when measuring sludge, sewage, etc., the electromagnetic flowmeter must be installed vertically and keep the flow direction from bottom to top to ensure that the electromagnetic flowmeter is always full of pipes and at the same time It can effectively reduce the appearance of bubbles.

8. The flow rate of the electromagnetic flowmeter is in the range of 0.3~12m/s. At this time, the diameter of the flowmeter is consistent with the diameter of the process pipeline. If the flow rate in the pipeline is low and cannot meet the requirements of the flow meter for the flow rate range, or the measurement accuracy is not high under this flow rate condition, try to increase the flow rate locally at the instrument part and adopt a shrink-tube type.

9. The electromagnetic flowmeter can be installed on a straight pipe or a horizontal or inclined pipe, but the center line of the two electrodes is required to be horizontal.

10. Subsequent use of electromagnetic flowmeterDuring the process, the instrument should be cleaned regularly and the flow meter should be checked regularly for problems:

(1) Electromagnetic flow meter sensor electrodes are worn, corroded, leaked, and scaled. Especially for non-cleaning liquids that precipitate, easily contaminate electrodes, and contain solid phases;

(2) The insulation of the excitation coil decreases;

(3) The insulation of the converter decreases;

(4) Converter circuit failure;

(5) The connecting cable is damaged, short-circuited, or damp;

(6) New changes in the instrument's operating conditions cannot be ruled out.

It can be seen from the above statistics that there are many problems related to the operation safety of the electromagnetic flowmeter when installing the flowmeter. Only reasonable Correct and effective installation can ensure that the electromagnetic flowmeter works more reliably and safely, ensuring accurate measurement and stable output. Of course, regular maintenance of electromagnetic flowmeters is also very important, and can even extend the service life of the instrument. Of course, regardless of electromagnetic flowmeters, the maintenance of any flowmeter is critical.