Germany KOBOLD flowmeter should be how to install?

There is no doubt that flow meters are widely used measuring instruments in sewage treatment plants. Therefore, the discussion about "the installation location of Kebao flowmeter" naturally became "lively":

Some water friends believe that "how to install the flowmeter" should be based on the installation location recommended by the equipment manufacturer. allow.

Some water friends believe that manufacturers should not be overly superstitious. Reliable manufacturers are better than those in books. If you encounter unreliable ones, just wait and deal with the consequences.

Then the question is, how to install the German KOBOLD flow meter? Today, Guanglian Automation has selected three commonly used Kebao flowmeters for discussion, hoping to be helpful to everyone.

Germany KOBOLD electromagnetic flowmeter

1. Principle of KOBOLD electromagnetic flowmeter

The electromagnetic flowmeter is based on Faraday’s law of electromagnetic induction and is used for Measure the volumetric flow of conductive liquids. Its working principle is to set up a magnetic field perpendicular to the flow direction in a closed pipe, and calculate the flow rate by measuring the induced electromotive force generated by the movement of conductive liquid in the magnetic field.

2. Advantages and disadvantages of electromagnetic flowmeter

1) Advantages of electromagnetic flowmeter

Measurement is not affected by fluid density, viscosity, temperature, pressure and other working conditions influence of conditions.

Has good corrosion resistance and wear resistance.

Compared with other forms of flow meters, the power consumption is relatively low, the zero point is stable, and the accuracy is high.

There are no throttling components in the measuring pipe, so when the medium flows through, there will be no pressure loss. The straight pipe section requirements are relatively low compared with other forms of flow meters.

A variety of installation forms allow users to choose, such as: integrated, split, wall-mounted, etc.

The flow meter can measure in both directions, display forward and reverse flow, and has a variety of output options, such as current, pulse, digital communication, HART, etc.

2) Disadvantages of KOBOLD electromagnetic flowmeter

It is basically unable to measure liquid media with very low conductivity or non-conductivity.

Easily affected by the surrounding strong magnetic field.

The price is relatively expensive, especially for large diameters.

3. Installation tips for KOBOLD electromagnetic flowmeter

1) Choose the installation point at the lower part of the pipe. After confirming the flow direction of the measured substance, the installation point should be selected so that the measuring conduit can be filled with liquid at any time to prevent errors caused by the indication not being at zero due to the absence of liquid in the measuring conduit.

2) The straight pipe section must be 5D in front and 3D in back (D is the nominal diameter of the sensor). In order to obtain instrument measurement accuracy, the length of the straight pipe section on the upstream side of the sensor is not less than 5D, and the length of the downstream side is not less than 3D. If there are more than two elbows or other flow-blocking parts on the upstream side of the sensor, the front straight pipe section should be larger than 10D.

3) LetterNo. electrode is in the horizontal direction. When installing horizontally, the electrode axis should be parallel to the horizon, because the electrode at the bottom is easily covered by sediment, and the occasional bubbles in the measured medium may rub against and cover the electrode surface, causing the output signal to fluctuate.

4) Try to avoid vibration sources and magnetic sources (high-power motors, transformers, etc.). Since the measurement induced voltage of the electromagnetic flowmeter is very small and low, it is easily affected by external electromagnetic noise, so a reliable ground connection (cross-over) should be made during installation.

The following principles should be followed when selecting the installation location:

Choose a straight section of the channel with the same size, avoid or stay away from the bends, and the length of the straight channel should be average The length should not be less than 10 times the width of the throat;

Choose a location where the flow pattern is gentle and stay away from water bodies with hydraulic jumps;

In channels with large longitudinal slopes, the flow If the state is complex, a slow flow plate or energy dissipation tank can be installed upstream of the tank to change the flow pattern of the water body.

The following points should be paid attention to when installing the tank:

There should be a 1:4 slope between the bottom plane of the connection between the channel and the tank, and the side walls of the channel should be connected with curved surfaces or flat surfaces. (Curved surface: curvature >2 times the highest water level; straight surface should be 45° with the centerline).

The inlet shrinkage section should be installed horizontally.

The center line of the channel and the center line of the tank should remain on the same axis.

After the tank is installed, the water level in the upstream channel will be high. In order to avoid the overflow of the channel water, the solution can be solved by heightening the channel wall or deepening the channel. However, when deepening the channel, care should be taken to avoid reverse flow or flooding of the water out of the tank. flow.

The side walls on both sides of the throat should be parallel to each other and vertical.

When using concrete backfill to reinforce the tank, on the premise of ensuring firmness, it is necessary to ensure that the left and right sides of the tank are horizontal and symmetrical along the water flow axis to avoid tilt or deformation of the tank.