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Typical failure and analysis of electromagnetic flowmeter in coal chemical application
Jan 08, 2019

Typical failure and analysis of electromagnetic flowmeter in coal chemical application

 Abstract: As an important part of modern industrial production, instruments play an important role in the production of coal chemical enterprises. Based on the application status of coal chemical instruments, the paper first analyzes the common faults and basic types of instruments, and then analyzes the troubleshooting methods of typical faults of chemical instruments, and proposes corresponding solutions, hoping to improve the use of instruments for coal chemical enterprises. Production efficiency creates conditions.

Typical failure and analysis of electromagnetic flowmeter in coal chemical application

1 Overview of common faults in coal chemical instruments

With the continuous expansion of the production scale of modern coal chemical enterprises, the application and expansion of various intelligent instruments have become an important technical support for enterprise development. From the point of view of the nature of the industry itself, coal chemical industry has the characteristics of strong process and complete closure. Especially with the continuous expansion of the application scale of intelligent instruments, the current production technology and process flow of coal chemical industry has entered a more sophisticated era. In this process, once the instrument fails, not only will the production parameters not be accurately controlled, but also safety accidents and production risks, which will seriously threaten the survival and development of the enterprise. In the process of using the instrument, there may be problems such as high index, low level and insufficient stability. In addition to one of the equipment problems of the meter itself, faults may occur due to changes in external factors. When the instrument fails, how to find the fault in the first time and eliminate it is an important channel for the enterprise to improve the fluency of the production. Generally, the maintenance personnel are familiar with the types and basic working principles of different instruments, find the structural points and have a certain understanding of the equipment produced. , familiar with the process, so that you can be aware of the troubleshooting process. When troubleshooting, we must take into account the system's own problems and production process problems, and then make judgments and treatments while ensuring that both problems are properly solved.


Typical failure and analysis of electromagnetic flowmeter in coal chemical application

2 Typical faults and troubleshooting methods for coal chemical instruments

2.1 High pressure boiler furnace negative pressure drop

When the negative pressure value of the high pressure furnace is monitored, if the negative pressure value drops abnormally or even drops to the minimum value, it indicates that the stability of the instrument has a big problem. In the case of similar situations, it is first necessary to adjust the regulator, adjust the remote control state to the lowermost position, and adjust the opening of the valve according to actual needs. At this time, it is necessary to check the transmitter and analyze the vibration changes of the signal pipeline. If it is found to be broken, it needs to be replaced immediately. In addition, when there is a problem in the automatic control system, the maximum negative pressure may be self-adjusted. At this time, the valve at the outlet of the fan may be faulty and the inner wall of the entire high-pressure furnace may be damaged. In general, the simplest way to handle this fault is to replace the signal line and quickly return to normal operation.


Typical failure and analysis of electromagnetic flowmeter in coal chemical application

2.2 Coal mill system thermal resistance temperature signal is abnormal

When the temperature measurement component is inspected at the production site, the temperature and resistance values can be tested by means of a multimeter. After the index is normal, a further troubleshooting method can be selected for fault diagnosis. In general, the common way is to use signal transmission cable shielding and grounding monitoring to deal with it. At this time, it can also be solved by means of thermal resistance replacement. In most cases, after the cause of the fault is discovered, the cable needs to be re-architected. If it cannot be solved, the following two technical means are needed: First, the signal transmission mode is changed, and the signal conversion can be actually performed indoors. The device converts the signal into a standard signal, which effectively prevents unnecessary interference in signal transmission while ensuring that the computer's temperature can reach normal levels. During the temperature change process, the location of the installation should be marked, preferably indoors, but it will also increase the cost within a certain range. Second, by changing the grounding of the signal to adjust, the temperature measurement signal of the thermal resistance can be changed to the common grounding mode, so that the different end points of the thermal resistance can be divided to ensure that the signal can be smoothly transmitted to the earth. Reduce the problem of mutual interference.


2.3 Electromagnetic flowmeter numerical fluctuation

There are many failure factors in the numerical fluctuation of the electromagnetic flow meter, which are generally caused by the installation of the flow meter or changes in external environmental factors. When this problem occurs, first adjust the installation method of the flowmeter, check the insulation of the sensor and the magnetic coil according to the actual situation of the installation; secondly, open the junction box, and then observe the change after drying. In the end, after the interior of the junction box is restored to dry, it is necessary to use silicone to seal the part of the line to ensure that no water is entering. At this time, the fault can be basically eliminated.


Typical failure and analysis of electromagnetic flowmeter in coal chemical application

2.4 Instrument unit mutual interference

In the normal use of the instrument, the coal chemical pipeline is often equipped with two units of flow regulation and pressure regulation. These two units can cooperate with each other under normal use conditions to complete the operation task. However, if there is a problem with the cooperation of the two, they will interfere with each other, causing problems in the pressure control system of the pipeline, and ultimately affecting the normal operation of the regulation system. In order to solve the problem of mutual interference, it is necessary to adjust the parameters of the regulator, compare the parameters of the regulator of the amplification flow and the pressure regulator, and adjust the proportionality to a suitable range that does not conflict with each other, thus reducing the flow regulation for the pressure. The effect of the adjustment ensures the overall stability of the parameters.


3 Summary

In summary, coal chemical production itself has the characteristics of high precision, large number of equipment and difficulty in coordination. If manual parameter recording and adjustment work is used, it will not only bring repetitive and high-intensity work to workers, but also bring new problems and risks due to personal operation errors. Through instrument troubleshooting, improving instrument accuracy and application stability, it can effectively reduce the intensity of manual work, timely identify production problems and eliminate faults, thereby improving risk resistance, strengthening the continuous production strength of enterprises, and ensuring stable market development and safe.