Industry new

Introduction to the application of electromagnetic flowmeter in the water supply industry

With the development of science and technology, new types of flow meters are constantly emerging, with a wide variety of products and different performances. Their use conditions and technical parameters are also different. According to the actual application of various flow meters used in the past, The problems, installation difficulty, performance price ratio and other issues have been carefully analyzed and compared. The electromagnetic flowmeter is sensitive, linear, and accurate. It is not affected by the temperature and viscosity of the measured medium during the measurement process. The advantages of factor influence. Therefore, in the selection of flow meters, the electromagnetic flowmeters produced by Kaifeng Open Flow Instrument Co., Ltd. are mainly used.

After years of practical application, we have realized that in order to make the electromagnetic flowmeter safe and stable, we should create better site conditions, and carry out proper installation and commissioning in strict accordance with its technical requirements, and implement centralized management to ensure electromagnetic flowmeter. Work normally to achieve continuous and accurate metering. The following is the specific practice of the company in the application of electromagnetic flowmeters (taking the electromagnetic flowmeter of Kaifeng Kailiu Instrument Co., Ltd. as an example) for discussion.

First, the choice of the installation position of the electromagnetic flowmeter

The installation position of the electromagnetic flowmeter should meet the requirements of the electromagnetic flowmeter for the straight pipe sections before and after, that is, the length of the straight pipe section upstream of the electromagnetic flowmeter is greater than 5D (D is the pipe diameter), and the downstream straight pipe section is larger than 2D to ensure the axisymmetric distribution of the flow velocity, thus eliminating And the resulting measurement error.

The electromagnetic flowmeter should be installed in a location that avoids strong vibrations, avoids strong sources of interference, and should be filled with water.

Second, the correct installation of electromagnetic flowmeter

1, sensor installation

The installation of the electromagnetic flowmeter is divided into the installation of the sensor and the installation of the converter, especially the installation of the sensor, which requires water, pipe cutting, pumping, welding or grooving, which makes the installation work more difficult and requires long-term water stoppage. Caused a certain economic loss. In response to this situation, when we installed the flowmeter on the cast iron pipe, a new process was adopted, and the two short-plate compensators were replaced by two single-disc compensators, eliminating the need for the mouthing process and the maintenance time of the nozzle. Especially in the case that the valve is not tight enough, it can be operated with water. After the water is stopped, it takes only half a day to install a sensor to restore the water supply, thereby shortening the installation time, reducing the economic loss caused by water stoppage, and receiving certain social benefits.

2, the sensor housing is well grounded separately, is a necessary condition to ensure that the flowmeter is normal and stable measurement.

It is generally believed that the sensor is installed on a metal pipe, and the pipe is buried underground, and the pipeline is long. It is itself a large grounding pole, and the instrument does not need to be grounded. However, two problems are neglected. One is that the pipes are generally treated with anti-corrosion treatment. The other is that the connecting flange and the pipe are separated by a mouth or rubber pad, thereby causing the grounding resistance of the sensor to be greatly increased, and the electromagnetic flowmeter is normal. The operation has an impact.

In the actual application, we used to have an electromagnetic flowmeter that was not working properly after being put into use, sometimes there was no flow display, and even an empty pipe alarm prompt appeared. At that time, there was no result based on the fault phenomenon. Later, the sensor was grounded separately, and the fault phenomenon disappeared. It has been operating normally.

Therefore, after the installation of the electromagnetic flowmeter, the grounding resistance should be measured. If the resistance is too large, it is better to make a grounding pole to reduce the interference potential due to stray current.

Third, the use of the situation

After several years of actual operation and observation comparison, we believe that the operation of electromagnetic flowmeter in our company's production is better than the work of other instruments used before.

1. The electromagnetic flowmeter has high precision, good linearity and stable operation, which improves the accuracy of measurement and the credibility of data, and overcomes the problem that some instruments are not stable, which results in unreliable measurement data. After many on-site comparisons, the error is within the control range, which enhances the trust level of the instrument, and ends the unscientific measurement method of calculating the water volume according to the performance curve of the water pump, and the data collected by the instrument is taken as the standard, avoiding Human Factors.

2. The electromagnetic flowmeter has a simple structure, the sensor has no moving parts, and there is no measurement error or instrument failure caused by mechanical movement wear or impurity entanglement, so the failure rate is very low, the maintenance amount is greatly reduced, thereby saving a lot of manpower and material resources.

3. The electromagnetic flowmeter has a variety of interface circuits, which can be easily connected with the data acquisition terminal or computer to realize data acquisition, analysis and management automation.

Fourth, the management of electromagnetic flowmeter

1. Establish an electromagnetic flowmeter operation file, including the manufacturer, model, production date, installation location, pipe diameter, calibration time, etc. of the flowmeter to facilitate maintenance and management of the instrument.

2. Strengthen the inspection inspection work and conduct regular test calibration. We mainly use two methods. One is to use a relatively high precision portable flowmeter to measure the comparison with the electromagnetic flowmeter. The other is to use a flowmeter checker to verify the flow converter and check each The technical indicators are correct and the test data is archived.

3. Compare the test data with the previous test results, carefully analyze the research on the suspicious data, find out the possible causes, solve the problem in time, and make an analysis report on the flowmeter operation.

PREVIOUS：Electromagnetic flowmeter installation enviroNEXT：Electromagnetic flowmeter use requirements de