Application of Electromagnetic Flowmeter in Paper Industry
2022-04-24
The modern paper industry is a capital, technology, and energy-intensive industry with large-scale production. It has the characteristics of strong production continuity, complex process flow, high energy consumption, large raw material processing capacity, heavy pollution load and large investment.
Electromagnetic flowmeters occupy a dominant position in the paper industry. The main reason is that the measurement of the electromagnetic flowmeter is not affected by the density, temperature, pressure, viscosity, Reynolds number and conductivity changes of the fluid within a certain range; its measurement range is very large and can cover both turbulent and laminar flow. Velocity distribution, which is unmatched by other flow meters. Due to the simple structure of the electromagnetic flowmeter, there are no moving parts, disturbing parts and throttling parts that hinder the flow of the measured medium, and there will be no problems such as pipe blockage and wear. It can significantly save energy consumption and strictly control the discharge of environmental pollutants.
Model selection suggestion for electromagnetic flow meter.
1. Lining
The measured medium in the papermaking process has the characteristics of high temperature and high pressure, and has a large amount of chemicals, which is corrosive. Therefore, the electromagnetic flowmeters are all lined with high temperature resistant PTFE. Although the PTFE lining is resistant to high temperature, it is not resistant to negative pressure. In some special environments, such as the outlet of the medium-concentration riser, not only the medium concentration is high, the temperature is high, but also a vacuum phenomenon will occur from time to time. In this case, it is necessary to choose PFA lining.
2. Electrodes
The selection of electromagnetic flowmeter electrodes in the paper industry mainly considers two aspects: one is corrosion resistance; the other is anti-scaling.
A large amount of chemicals will be added in the papermaking process, such as NaOH, Na2SiO3, concentrated H2SO4, H2O2, etc. Different electrodes need to be selected for different chemicals. For example, tantalum electrodes should be used for strong acid dielectric electrodes, titanium electrodes are generally used for alkaline media, and 316L stainless steel electrodes can be used for conventional water measurement.
In the design of anti-fouling of electrodes, spherical electrodes can be selected for the medium mainly composed of fibrous substances for the general degree of fouling. The spherical electrode has a large contact area with the measured medium and is not easily covered by fibrous substances.
