萘是稠環芳烴，是有機化合物。分子式為C10H8，無色，有毒，易升華，片狀晶體，有特殊氣味。它是由焦化煤焦油和石油蒸餾大量生產的，主要用于鄰苯二甲酸酐的合成。過去，衛生球是由萘制成的，但是由于萘的毒性，現在已禁止使用萘作為一種成分。接觸萘和溶血性貧血會導致肝和神經系統損害，白內障和視網膜出血。合理預期萘是人類致癌物，可能與喉癌和結直腸癌的風險增加有關。

Naphthalene is a polycyclic aromatic hydrocarbon and an organic compound. The molecular formula is C10H8, colorless, toxic, prone to sublimation, plate-like crystals, with a special odor. It is produced in large quantities from coking coal tar and petroleum distillation, mainly used for the synthesis of phthalic anhydride. In the past, sanitary balls were made from naphthalene, but due to its toxicity, the use of naphthalene as a component is now prohibited. Exposure to naphthalene and hemolytic anemia can lead to liver and nervous system damage, cataracts, and retinal hemorrhage. Reasonable expectations suggest that naphthalene is a human carcinogen and may be associated with an increased risk of laryngeal and colorectal cancer.

生產和制備簡介：

Introduction to Production and Preparation:

從石油烴類制造：催化重整油，輕循環油催化裂化，乙烯裂解副產物焦油等；

From petroleum hydrocarbon manufacturing: catalytic reforming oil, light cycle oil catalytic cracking, ethylene cracking by-product tar, etc;

與煤焦油分離，高溫煤焦油中的萘約占8％-12％。將煤焦油蒸餾，將煤油切碎，并通過脫酚和脫喹啉蒸餾獲得終的萘。

Separate from coal tar, naphthalene in high-temperature coal tar accounts for about 8% -12%. Distill the coal tar, cut the kerosene into small pieces, and obtain the final naphthalene through dephenolization and quinoline removal distillation.

精萘是將粗萘精制而成。

Refined naphthalene is refined from crude naphthalene.

降膜分步結晶結晶生產工藝流程由產品生產工藝系統，能量系統，氮氣密封系統和計算機控制系統組成。生產過程系統將大周期用作生產周期。每個大周期包含4個小周期，每個小周期包含4至6個段。每個段包括3個步驟：結晶，部分熔融和全部熔融；

The production process of falling film fractional crystallization crystallization consists of a product production process system, an energy system, a nitrogen sealing system, and a computer control system. The production process system uses large cycles as production cycles. Each large cycle contains 4 small cycles, and each small cycle contains 4 to 6 segments. Each section includes three steps: crystallization, partial melting, and complete melting;

從工業萘裝置送來的液態工業萘被送到餾出罐，當進行第四階段結晶操作時，罐中的原料液體被送到動態結晶器收集槽

The liquid industrial naphthalene sent from the industrial naphthalene unit is sent to the distillation tank. When the fourth stage crystallization operation is carried out, the raw material liquid in the tank is sent to the dynamic crystallizer collection tank

未結晶的萘油和汗液放入純度較低的分餾罐中，并且在五階段中可以將全部熔體用作原料。可以根據預定程序在六個階段的晶體精制之后獲得精致的萘。為了提高萘的萃取率，可以將富含硫茚的餾分送入靜態結晶器進行處理。從靜態結晶器中獲得的產品返回到動態結晶系統的相應分餾罐中，殘留液體可以作為減水劑出售。由于該設備同時使用動態和靜態結晶器，因此不僅可以確保更高的萘回收率，而且可以減少能耗。

Uncrystallized naphthalene oil and sweat are placed in a lower purity fractionation tank, and in the fifth stage, all the melt can be used as raw materials. Refined naphthalene can be obtained after six stages of crystal refinement according to the predetermined program. In order to improve the extraction rate of naphthalene, the fraction rich in sulfur indene can be sent to a static crystallizer for processing. The product obtained from the static crystallizer is returned to the corresponding distillation tank of the dynamic crystallization system, and the residual liquid can be sold as a water reducing agent. Due to the use of both dynamic and static crystallizers, this device not only ensures higher naphthalene recovery rates but also reduces energy consumption.