Integrated electromagnetic sensor flowmeter for sewage treatment

The selection of electromagnetic flow meters is a very important task in applications. Firstly, the diameter, lining, and electrode materials of the flow meter must be selected based on the relevant parameters of the measured fluid. Secondly, the protection level of the instrument casing and output function must be selected according to the user's requirements for the flow meter. According to relevant information, 2/3 of instrument failures in actual use are caused by incorrect instrument selection. Please pay special attention. The selection work generally includes the following parts:

（1） Collect relevant parameters of the tested fluid, such as fluid name, maximum/minimum flow rate, maximum/minimum pressure, maximum/minimum temperature, fluid conductivity, wear and corrosion of the fluid on the instrument, presence of backflow (reverse flow), and negative pressure inside the pipe.

（2） The relationship between flow velocity, diameter, and measurement accuracy is related to the diameter and flow velocity of the flowmeter. The higher the flow velocity, the higher the accuracy. Conversely, the lower the flow velocity, the lower the accuracy. The lowest flow velocity that this flowmeter can measure is 0.1m/s (at this flow velocity, the measurement accuracy can be guaranteed).

（3） In the comparison table of flowmeter diameter and flow range, the flow velocity corresponding to the smallest and largest flow rates is 0.1~10m/s, and the flow formula is Q=0.002826VD2, where Q - flow rate m3/h, V - flow velocity m/s, and D - diameter mm. You can choose the appropriate flowmeter diameter based on the flow range in the table. When measuring clean water, the economic flow velocity is 1.5~3m/s, which reduces pipe loss and pump power consumption; When measuring liquids that are prone to crystallization and scaling, it is advisable to increase the flow rate appropriately to>3m/s. A high flow rate plays a self-cleaning role to prevent the liquid from adhering to the pipe wall and electrode; When measuring fluids with high wear such as slurry, the flow rate should be appropriately reduced to<2m/s to reduce the wear of the medium on the lining and electrodes. In practical applications, it is rare for the fluid flow velocity in pipelines to exceed 7m/s, and even rarer for it to exceed 10m/s.

Integrated electromagnetic sensor flowmeter for sewage treatmentinstall

1. In order to ensure the reliable and stable operation of the flowmeter, the following requirements should be noted when selecting the installation location:

⑴ Try to avoid magnetic objects and equipment with strong electromagnetic fields (such as large motors, transformers, etc.) to prevent the magnetic field from affecting the working magnetic field and flow signal of the sensor.

⑵ It should be installed in a dry and ventilated place as much as possible, and should not be installed in damp or water prone areas.

⑶ Avoid direct sunlight and rain as much as possible, and avoid environmental temperatures above 60 ℃ and relative humidity above 95%.

⑷ Choose a place that is easy to maintain and has convenient activities.

The flowmeter should be installed at the rear end of the water pump and must not be installed on the suction side; The valve should be installed on the downstream side of the flow.

2. In order to ensure the reliable and stable operation of the flowmeter, the following requirements should be noted when selecting the pipeline installation position:

The sensor can be installed on vertical, horizontal, or inclined pipelines, but it is required that the centerline of the two electrodes be in a horizontal state.

When the electromagnetic flowmeter is working, it is always required to fill the measuring tube with the measured medium. When installing horizontally, in order to ensure this, the elevation of the sensor installation position may be slightly lower than the elevation of the pipeline if necessary,

Precautions for flowmeter installation: When handling and lifting sensors, the sling should be placed on the neck or lifting ring at both ends of the sensor. Do not insert a pipe rod into the measuring tube for lifting to avoid damaging the lining (see Figure 14). During the lifting and handling process, it is necessary to prevent the sensor lining and junction box from being damaged by collision.