Current situation and existing problems of industrial naphthalene area

萘在远低于沸点温度下，就具有很大的蒸气压，因而在加热时，固体萘能够不经过液态直接变为萘蒸气，而萘蒸气在冷却时又可不经过液态而直接转变为银白色固体。因此，固体和液体萘均能以这种形式转变为萘粉尘。萘粉尘的主要散发点有：萘的贮槽、萘的成型设备等。

When the temperature of naphthalene is far below the boiling point, it has a large vapor pressure. Therefore, when heated, solid naphthalene can directly change into naphthalene vapor without going through liquid, and when cooled, naphthalene vapor can directly change into silver white solid without going through liquid. Therefore, both solid and liquid naphthalene can be transformed into naphthalene dust in this form. The main emission points of naphthalene dust include: naphthalene storage tank, naphthalene forming equipment, etc.

某焦化厂的工业萘产品槽区域包括6个工业萘储槽、液萘发货装置和萘结片系统，废气源主要有：6个工业萘槽的放散气(2个工业萘高置槽、3个工业萘产品槽、油配装置区1个3000m3工业萘大槽)、液萘发货产生的废气、萘结片机组产生的废气。工业萘高置槽、工业萘产品槽、工业萘大槽、液萘发货、萘结片机组产生的萘挥发废气，属于非甲烷总烃。

The industrial naphthalene product tank area of a coking plant includes 6 industrial naphthalene storage tanks, liquid naphthalene delivery unit and naphthalene flake system. The waste gas sources mainly include: the exhaust gas of 6 industrial naphthalene tanks (2 industrial naphthalene high-level tanks, 3 industrial naphthalene product tanks, 1 3000m3 industrial naphthalene tank in the oil distribution unit area), the waste gas generated by liquid naphthalene delivery and the waste gas generated by naphthalene flake unit. The naphthalene volatile waste gas generated by industrial naphthalene high setting tank, industrial naphthalene product tank, industrial naphthalene large tank, liquid naphthalene delivery and naphthalene flake unit belongs to non methane total hydrocarbon.

萘结片机组产生的废气有一套布袋式捕集装置，主要是将萘结片生产过程中产生的升华萘通过排风机抽入脉冲袋式除尘器，升华萘被布袋捕集回收，尾气经消声器由烟囱外排。目前运行效果良好，但6个工业萘储槽、液萘发货产生的废气没有收集装置和设施，产生的废气无组织排放，严重影响了环境。工业萘产品槽区域废气主要存在如下问题：1)工业萘槽无废气处理设施，升华萘容易通过槽顶取样口、放散口逸出，影响环境;2)工业萘槽收送料前后均采用蒸气吹扫，吹扫作业会造成槽内升华萘从槽顶逸出，影响环境;3)液萘发货产生的废气未经处理无组织排放，影响大气环境。

The waste gas generated by the naphthalene flake unit has a set of bag type capture device, which mainly pumps the sublimated naphthalene generated in the production process of naphthalene flakes into the pulse bag dust collector through the exhaust fan, the sublimated naphthalene is captured and recovered by the bag, and the tail gas is discharged from the chimney through the muffler. At present, the operation effect is good, but the waste gas generated by 6 industrial naphthalene storage tanks and liquid naphthalene delivery has no collection devices and facilities, and the waste gas is discharged unorganized, which has seriously affected the environment. The waste gas in the industrial naphthalene product tank area mainly has the following problems: 1) there is no waste gas treatment facility in the industrial naphthalene tank, and the sublimated naphthalene is easy to escape through the sampling port and discharge port on the tank top, affecting the environment; 2) The industrial naphthalene tank is purged by steam before and after receiving and feeding. The purging operation will cause the sublimated naphthalene in the tank to escape from the tank top and affect the environment; 3) The waste gas generated from the delivery of liquid naphthalene is discharged without treatment, affecting the atmospheric environment.