Why is Jiwei Magnetic Level Indicator Competent for DMF Level Measurement?

In the bidding DMF （dimethylformamide） project of a large state-owned chemical company in Shandong province, Jiwei successfully won the bid for 120 magnetic level indicators, which would be used for level measurement of various storage tanks such as methanol receiving tank, DMF distiller, acidic wastewater tank, etc. The magnetic level indicators have been installed and in operation for more than half a year. So far all of them have performed very well under the complicated working conditions. They are highly evaluated by the user. So what are the difficulties in DMF level measurement? Why is Jiwei Magnetic Level Indicator so competent in the bidding DMF project?

DMF and its production process

DMF is a transparent liquid. It is miscible with water and most organic solvents. It can be ignited by a flame or spontaneous ignites at high temperature and explodes. It can react violently or even explode with concentrated sulfuric acid, fuming nitric acid. It is flammable as Hazard mark 7 and mainly used as an industrial solvent. In the pharmaceutical industry, it is used to produce vitamins and hormones. It can also be used for making pesticide.

There are many methods to produce DMF. Two-steps formic acid esterification method, two-steps methanol dehydrogenation method, dimethylamine and Carbon monoxide (CO) one-step method. CO one-step method is an energy saving advanced process. It is less expensive, can produce high purity DMF products, and is particularly suitable for large-scale industrial production.

Difficulties in level measurement of DMF

The bidding demonstration project in the chemical industry of Shandong province was in phase I of the project. It placed higher specifications for magnetic level indicators to be used in the application. Considering the properties of the measured medium and local climate characteristics, there are following difficulties in level measurement of DMF:

1. As a flammable liquid, DMF is easy to be ignited by a flame or spontaneous ignites at high temperature and explodes. The selected level meter must meet explosion-proof requirements.

2. The intermediate product in the DMF production process contains hydrogen ions and it is corrosive. General stainless steel cannot be used for the selected magnetic level indicators. It must be designed and manufactured with material that has strong corrosion resistance.

3. Because most of the storage tanks are located outdoors, and dust and moisture there are usually heavier. It requires that magnetic level indicators in the application must have a higher level of ingress protection. Otherwise, the display panel of the magnetic level indicator will very easily become dusty or “scratching face” which not only affects the accuracy of level measurement but also seriously affects service life of the instrument.

4. The onsite DMF storage tanks are generally tall and the display panel of common magnetic level indicator is generally narrower. It does not help the real-time observation for the operator.

5. Most tanks used in the process of DMF production are quite tall which causes inconvenient observation in level measurement onsite. In order to monitor the liquid level in real time, it is necessary to install a remote transmitter to transmit the liquid level signal to a remote control center. Due to the flammable and explosive characteristics of DMF, the selected remote transmitter must be not only in high quality but also certified for high level of explosion protection. Otherwise the remote control of liquid level cannot be reliable, accidents are likely to happen and normal production will be affected.

6. Because the project is in Shandong province, north of China, the temperature there is extremely low in winter. In order to prevent the liquid from freezing and affecting normal level measurement, it is necessary to provide a thermal insulation device for the magnetic level indicator.

Up to now, Jiwei has filed seven patent applications for Flap-11 series products, including invention patent and utility patent. Five of them have been approved; two of them are in verification. The Jiwei Flap-11 series product possesses features and strength of the similar products in the market. And on top of that, Jiwei has developed innovative techniques in design and production process, focused on details of the manufacturing technologies and implemented strict control of the production flow and quality inspection. The Jiwei Flap-11 series product overcomes common defects and failures of similar products.

The Jiwei Flap-11 Magnetic Level Indicator is very competitive because of the following advantages and features.

1. With a broader display panel and magnetic flaps, it greatly increases the visual distance and viewing angle of the instrument. With a larger sharp scale and digits, the display panel appears beautiful and elegant. It is convenient for the operator to observe the liquid level onsite.

2. Innovative design of magnetic coupling system effectively avoids display error caused by wrong flip of magnetic flaps and greatly improves reliability of the instrument.

3. Jiwei offers F4/F46 lined chambers designed and manufactured with multiple patented lining techniques. F4 (PTFE) lining can be applied for the majority of strong corrosive liquids with poor permeability. F46 (FEP) lining can be applied for strong corrosive liquids with good permeability, such as liquid chlorine, bromine water.

4. Unique design of the end cap and glass sealing technology ensure that Jiwei Flap-11 exceeds national Ingress Protection standard IP54 and reaches a higher level of IP65, IP66/IP67. It is suitable for outdoor applications where there is heavy dust in autumn and winter while higher humidity in summer.

5. Jiwei Reed-11 remote transmitter is certified for the highest explosion protection level among similar products in the market. Jiwei holds both flameproof enclosure (Ex d IIC T6) and intrinsic safety (Ex ia IIC T6) certificates for Reed-11. Because high quality reed switches and signal processors are used as its core components, and the outer protective tube is made of 304 stainless steel, it improves corrosion resistance and reliability of the remote transmitter. Compared with similar products from other manufacturers, the glass reed switches used in Reed-11 are more reliable and durable. This makes Reed-11 well suited for level measurement of flammable and explosive liquids such as DMF.

6. For applications under severe winter, Jiwei offers a thermal insulator as an accessory to its magnetic level indicator to keep the instrument warm and working reliably in cold winter. Electric tracing and vacuum jackets are also available for selection.

Jiwei Flap-11 Magnetic Level Indicators have been installed and put into operation in the demonstration project in Shandong province for DMF production for about half a year and they have been tested under extreme hot and cold weather. Up to now, liquid level display error caused by wrong flip of magnetic flaps has never happened. Remote level reading through a remote transmitter has always been consistent with real liquid level onsite. Jiwei Flap-11 Magnetic Level Indicators have been working reliably and ensured the stable DMF production operation. Its excellent quality is highly praised by the operator onsite.