Application of Remote Transmitters in PVC Production
Recently, Jiwei Reed-11 Remote Transmitter won the bid in a new PVC project of a large state-owned enterprise. The project proposes to install Magnetic Level Indicators to realize remote real-time measurement and control of the liquid level in PVC production storage tanks.
Polyvinyl Chloride (PVC) plastic, commonly known as “vinyl,” has become one of the most widely-used types of plastics. Pure polyvinyl chloride is a white, brittle solid. Polyvinyl chloride is produced by polymerization of the vinyl chloride monomer (VCM). About 80% of production involves suspension polymerization. VCM and water are introduced into the reactor along with a polymerization initiator and other additives. The contents of the reaction vessel are pressurized and continually mixed to maintain the suspension and ensure a uniform particle size of the PVC resin. The reaction is exothermic and thus requires cooling. As the volume is reduced during the reaction (PVC is denser than VCM), water is continually added to the mixture to maintain the suspension.
Magnetic Level Indicators are installed to monitor the real time liquid level for each PVC production tank, because the ethylene, liquid chlorine and vinyl chloride monomers are toxic and flammable, it is necessary to monitor the liquid level to avoid leakage or deflagration accidents. So, the performance of level sensors with stable, reliable and durable characteristics are significant.
Because the measured medium is toxic, corrosive, gasified, flammable and explosive, it is difficult to monitor the liquid level on-site, and mostly need to transmit the liquid level signal to a central control room simultaneously. Reed Transmitter is usually tied to measuring floats and operated together with Magnetic Level Indicator. Through the remote transmission of liquid level signal to the control room in the form of 4-20mA current, the liquid level height can be controlled remotely in real time. However, the quality of domestic brands often occurs the following problems:
1. Easy to penetrate vapor and dust with poor sealing techniques, affects product’s the stability and service life.
2. Most made with glass reed, cheap but poor in quality and easy to damage.
3. None explosion-proof design, cannot be used in dangerous occasions.
4. Circuits are made of cheap electronic components with short service life.
5. Poor corrosion-resistance material, not suitable for liquid chlorine level measurement.
Jiwei Reed-11 Remote Transmitter possesses the features and strength of similar products in the market. But on top of that, we also have carried out extensive study on common problems of existing products in the market, and developed innovative techniques in design and production process to overcome the problems.
Compared with the similar products of other brands in the market, Jiwei Reed-11 Remote Transmitter has the following advantages:
● Purchased high quality reed switches in the international market, with long service life.
● Purchased TI CLT chips for 4～20mA output.
● Certified for both Flameproof Enclosure and Intrinsic Safety explosion protections.
● The ingress protection rating reaches to IP66/IP67.
● The chamber is made of 304 stainless steel with strong corrosion resistance.