Integration of self reling automation, Runzhong instrument and instrument network
Installation of magnetic float level gauge
Magnetic float liquid level meter is suitable for measuring liquid level and boundary of liquid level medium in container. In addition to field indication, it can also be equipped with remote transmitter and alarm (control) switch, with complete detection function. The direction of the indicator can be changed according to the user’s needs. The measurement range is large and not limited by the height of the tank. The indicating mechanism is completely isolated from the measured medium, so it has good sealing performance, high reliability and safe use. Simple structure, easy installation and maintenance.
When the magnetic float level meter measures liquid, it adopts the way of top mounting or by-pass pipe side mounting. A liquid level indicator, a liquid level switch and a liquid level transmitter are installed outside the main body of the magnetic column. When the floating ball and the magnetic unit change with the liquid level, the magnetic color block (magnetic flap) turns over; The magnetic liquid level switch acts at the corresponding liquid level point; At the same time, the liquid level sensor outputs standard variable resistance signal under the action of floating ball magnetic force, and then converts the resistance signal into 4 ~ 20mA current signal through the transmitter.
1. When the liquid level meter is put into operation, the valve of the lower liquid leading pipe should be opened first to let the liquid medium enter the main pipe smoothly, so as to avoid the liquid medium rising rapidly with the floating ball assembly, resulting in the failure or upset of the column turnover Center (in case of this phenomenon, the magnetic steel can be used for re correction after the rise and fall of the liquid level is stable)
2. In order not to damage the floating ball assembly during transportation, take the floating ball assembly out of the main pipe of the small liquid level meter before leaving the factory. After the liquid level gauge is installed, open the bottom drain flange, and then re install the floating ball assembly into the main body pipe. Pay attention that the heavy end of the floating ball assembly is upward and cannot be inverted.
3. According to the medium condition, the blowdown flange can be opened regularly to clean the precipitates in the main pipe
1. A stop valve is installed between the side mounted liquid level and the upper and lower liquid distribution pipes of the tested container to open or assemble the liquid level meter. On the other hand, it is convenient to maintain the liquid level. When the upper and lower stop valves are closed, the bottom drain flange of the magnetic float liquid level meter can be opened or the drain screw can be removed, and the main body of the liquid level meter can be cleaned by injecting clean water.
2. The cross-sectional area of the core wire for the connection between the transmitter of the matched remote liquid level meter and the secondary instrument shall be greater than 0.8mm2. When the core wire is laid in parallel with the AC power supply, the distance of at least 20cm shall be maintained. The core wire shall be laid separately through the iron pipe or with the shielded two core cable, and the shielding layer can only be grounded at one end.
3. The liquid level controller is selected, and its contact capacity is designed with resistive load. If non resistive or high-power load is used, intermediate relay shall be used for conversion.
4. It is not suitable to use the magnetic float level meter when the liquid medium contains suspended impurities and magnetophile substances (because these impurities will cause jamming to the float assembly)
5. According to the principle of buoyancy, the length of the float assembly is related to the medium density. Therefore, in the selection and design, it is necessary to consider that different media have different details
How to adjust the liquid level of magnetic float liquid level meter
Magnetic float liquid level meter is also called magnetic flap liquid level meter. Compared with other new types of instruments, its measurement method is more traditional. It works based on the principle of buoyancy and magnetic coupling. It can directly reflect the actual liquid level in the tank without other means. Its advantages of intuitive measurement are prominent, Through the selection of related types of equipment and technical means, the measurement can be more widely used in actual production. The specific adjustment steps are as follows:
1. Determination of medium density
The medium density can be measured by standard density meter, and the magnetic float liquid level meter can also be checked according to the specific data provided by the user. The medium density needs to be recorded to ensure that the medium density can meet the requirements of the liquid level meter application manual. Although the medium density has an effect on the indication of the liquid level meter in theory, the zero position and full degree value of the liquid level meter can be directly adjusted through the potentiometer in practical application.
2. Determination of reference zero
a) Use vernier calipers to measure the inner diameter D of the connecting pipeline. The magnetic float liquid level meter determines a lower ruler point of the standard liquid level on the upper part of the tank. If possible, it can be polished into a groove to avoid the swing of the sounding ruler and make marks;
b) When the water level is slightly higher than the water inlet pipe of the liquid level meter, stop the water injection. Turn over the manual ball valve e at the lower connecting flange of the magnetic rotameter, and loosen the connecting flange f between the tank and the liquid level meter to be calibrated (do not take it down, so that the water can not be flushed). When there is no surging flow in the pipeline, close E and remove the flange, When the liquid in the tank is stable, turn on e, and then wait until it is in trickle condition and stable for 1min (if necessary, drain water through the drain valve to improve the inspection efficiency);
c) The magnetic float liquid level meter uses sounding steel tape to measure the distance HA from the measuring point to the water surface, and the actual zero height h 0 = ha-d / 2, which is the zero point of the liquid level meter.
3. Calibration of each level point
a) Install the flange, close e, and continue to inject water into the tank until the flap indicates the main scale of liquid level to be calibrated. After the water surface is stable, measure the output current II and the water level height hi. The actual liquid level is: H0 = H0 hi = ha – D / 2 – hi;
b) Continue to measure the magnetic rotameter at other points until full scale.
4. Adjustment of zero and full level of liquid level
While determining the reference zero point, adjust the zero point potentiometer to make the output electrical signal display 4mA; The full-scale adjustment is carried out at the upper limit of the standard liquid level, and the full-scale potentiometer is increased to make the output electrical signal display 20mA. If there is a deviation in the down stroke measurement of the magnetic rotameter, it should be adjusted according to this method. The field calibration needs to repeat the above steps for three return measurements.
Four correct connection ways of magnetic float level gauge
Connection mode selection is very important. Why do you say that? For example, the enterprises that produce hygienic food require that they can use the quick and easy to install and keep it hygienic, so the demand points of each enterprise are different. Therefore, for manufacturers, when communicating with customers, they will inevitably ask each other what is the connection mode of the magnetic float liquid level gauge to ensure the normal connection. At this time, some customers may not understand this aspect. It is necessary for manufacturers or customers to explain clearly to customers. In order to let customers choose their own appropriate connection mode, Ruiling focuses on four correct connection modes of magnetic float level gauge
1、 Flange connection: this connection method is more traditional. Both ends of the magnetic float type liquid level meter have flanges that can be connected. When connecting with the pipeline, just fix the flanges at both ends and the flange on the pipeline with bolts. This connection can be a one-way device. This kind of sensor is small and suitable for small pipes.
2、 Sanitary connection: this connection is used in some small-diameter pipes nowadays, and it is often called clamp connection. Through this connection, the flowmeter can be quickly installed and disassembled, and its daily cleaning and maintenance are also very convenient. The average content of liquid-solid two-phase suspension liquid, such as mud, pulp, pulp and so on.
3、 Clamping connection: this connection method is more advanced. Some flowmeters without flange use this connection method, which can be clamped between two flanges of the pipeline with bolts. The connection method is relatively simple. It is necessary for us to know the installation method of the magnetic float type liquid level meter, so that the error will not appear when the clamping connection is stopped.
4. Threaded connection: some small-diameter flowmeters use threaded connection, which is commonly used in medical and food operation industries. In addition, this connection also has some applications in oil and gas exploration.
Editor in charge: yyx