Sewage discharge is a key parameter that needs to be tested. Wastewater contains a mixture of particles, suspensions, solids and liquids and is corrosive. The main feature of the electromagnetic flowmeter is the ability to measure the flow rate of acids, bases, salt solutions, and solid particles(such as mud) or fibrous liquids. Therefore, electromagnetic flowmeters can be used to measure the flow of untreated sewage.
It is important to select instrument types including electromagnetic flowmeters. In practical applications, some of the instrument's faults are caused by wrong selection or improper use. Therefore, after selecting the electromagnetic flowmeter, the following factors should be considered:
1. Aperture Selection
According to the diameter of the process pipe, pipe pressure and sewage flow provided by the sewage treatment plant, an electromagnetic flowmeter of appropriate diameter is selected, and the installation site does not require the contraction and expansion of the pipeline.
2. Select lining and electrode material
The electromagnetic flowmeter is mainly used to measure fluid flow, and the conductivity is greater than or equal to 5 pressure S/cm. Different lining and electrode materials shall be selected according to the corrosivity, wear, temperature and condensation characteristics of the material to be tested and its carrying capacity.
Electromagnetic flowmeter lining materials include: corrosion resistant medium, generally low concentration of acid, alkali, neoprene rubber materials, abrasion-resistant and corrosion-resistant polyurethane rubber, strong corrosion resistance, suitable for high temperature PTFE, the chemical properties of the same thing PTFE tensile, compression, Fep, dilute acid resistance, alkali, salt polyethylene & lt; Temperature 60 °C, temperature & lt; 100 °C PPS, etc..
The electrode material is installed on the inner wall of the pipeline and is in direct contact with the measured material. Therefore, the selection should be based on the corrosivity of the tested material. Electromagnetic flowmeter electrode materials are: salt-and less than 50 % alkaline solution and titanium(Ti) electrodes, concentration of acid and tantalum(Ta) electrodes, corrosion resistance of precious metal platinum electrodes, Not suitable for Hartz alloy electrodes and C not suitable for Bhazi alloy electrodes, generally strong corrosion resistance, but 316 L stainless steel and other low prices
Neoprene rubber lining and 316 L stainless steel electrodes are used to treat domestic and industrial wastewater.
3. Select Protection Level
According to national standards, sensors have two levels of protection: IP65 water spray and IP68 diving. According to the actual installation location of the user in the low well, the sensor chooses IP68 dust diving type.
4. Choose Other Functions
(1) For the selected basic type, the electromagnetic flow is LCD display, 4-20ma current output and 0-1khz frequency output. The Rs-485 communication port function should be added according to the requirements of flow meters and computer communications.
(2) For sensors installed underground, a separate form should be chosen.