Application of Fork Liquid Level Switches in Level Control for White Oil Tanks
Some time ago, a large petrochemical plant in Zhangzhou selected Jiwei Ring-11 Fork Liquid Level Switches with flameproof enclosure explosion protection certificate as high/low oil level switch sensors for their white oil tanks after investigating and comparing products in the market in their procurement process. The first batch of 204 units was purchased and used to substitute for imported products in high/low oil level control for white oil tanks.
In the petrochemical industry, a large number of separating pumps and sealed tanks are needed for refining crude oil and white oil or methanol is used as sealing and insulating fluid for mechanical sealing in separating pumps and sealed tanks. White oil is the most commonly used sealing fluid.
In practice, flushing of pump´s mechanical sealing is mostly series connected double-end mechanical sealing. A buffer tank in the equipment provides buffer fluids (usually white oil or methanol at normal temperature) for air-side sealing. The valve (normally open) above the buffer tank is to ensure the pressure of buffer fluids is lower than medium pressure. There is a viewing mirror in the buffer tank and a line is usually drawn next to it. This line indicates the normal fluid level when the mechanical sealing is normally functioning. When the fluid level is higher than the line, it means the mechanical sealing on the medium side is leaking so the medium enters into the buffer tank and the pressure in the buffer tank rises and triggers the pressure switch to send out an alarm signal. When the fluid level is lower than the line, it means the mechanical sealing on the air-side is leaking so buffer fluid in the buffer tank enters into air and lower fluid level triggers the liquid level switch installed on the buffer tank to send an alarm signal. If the fluid level in the white oil tank is not properly controlled, poor sealing could happen without warning and lead to leakage of petrochemical products to cause safety accidents. Therefore, companies in the petrochemical industry have always paid attention to the level measurement and control for white oil tanks. In petrochemical industry level switches for this purpose were purchased from abroad before, such as the U.S.A or Germany, to meet high technical requirements for reliability and explosion protection and ensure safe and reliable operation of the equipment.
It was the importance of level control for white oil tanks that the large petrochemical plant in Zhangzhou compared many similar products in the market at home and abroad in the procurement process. They found Jiwei Fork Liquid Level Switch could be competent and comparable to those imported brands in quality and performance. Specifically, Jiwei Ring-11 has a compact design and its fork body is only 40mm long, suitable for application in pipelines. The measurable medium density can be as low as 0.5g/cm³. It is with strong interference resistance and its operation is not affected by foams, bobbles, vibrations, fluid viscosity and other properties of the measuring fluid. Jiwei Ring-11 has explosion protection certificates for both flameproof enclosure (Ex d IIC T6) and intrinsic safety (Ex ia IIC T6). It is reliable and safe to operate. It offers an effective solution for applications in high pressure explosive areas for low density medium level measurement. It is very suitable for liquid level control in petrochemical industries such as PetroChina and Sinopec.
On trial, the performance of the Jiwei Ring-11 Fork Liquid Level Switch was very stable. Jiwei Ring-11 Fork Liquid Level Switch finally won the bid with its “high quality, low price, high reliability and high cost-effective ratio”.
Jiwei Ring-11 Fork Liquid Level Switch not only performed very well in early trial in the petrochemical plant but also worked excellently later when it was installed in batch. Its reliable and accurate level measurement and control won the full recognition and trust from the customer.
Note: White oil, alias paraffin oil, white-colored oil, mineral oil. It is a mixture of refined liquid hydrocarbons, mainly a mixture of saturated naphthenes and paraffinic. It is obtained from crude oil through the refining process of atmospheric fractionation, vacuum fractionation, solvent extraction, dewaxing and hydrogenation. White oil is usually classified according to the purity of saturated hydrocarbons it contains. Common industrial white oil is suitable for chemical fiber or aluminum processing, rubber plasticization, etc. It is also suitable for lubricating textile machinery and precision instruments. It can be used as sealing oil for compressors as well. Cosmetic-grade white oil can be used as raw material in the cosmetic industry to make hair cream, hair oil, lipstick, skin care cream etc. Besides that, it is also suitable for food processing and pesticide production. Food-grade white oil can be used for food glazing, anti-sticking, demoulding, defoaming, sealing, polishing, also for rust prevention and lubrication of food processing machinery and surgical instruments. It can be used to extend the storage time as well for wine vinegar, fruits, vegetables, canned food etc.