The content of naphthalene in raw gas is usually 10-15g / m3, and most of naphthalene is dissolved in the tar condensed in the gas collector and primary cooler. The naphthalene in the gas has a great influence on the ammonia washing operation. When the content of naphthalene in the gas is high, the naphthalene will deposit together with the scale in the ammonia washing process, which will cause the blockage of the ammonia washing equipment, thus destroying the normal operation of ammonia washing and reducing the ammonia recovery rate. More seriously, the corrosive gases such as ammonia, hydrogen sulfide and hydrogen cyanide enter the crude benzene section along with the gas Serious corrosion and clogging of the equipment for debinding. Therefore, naphthalene in gas must be cleaned according to the requirements of ammonia washing.

　　目前，各焦化企业采用的油洗萘工艺一般分为两种，一种是煤气终于冷却与洗萘同时进行的终冷油洗萘，称为冷油法洗萘。另一种是终冷前油洗萘，称为热油法洗萘。洗萘采用的吸收剂通常为本厂产的焦油洗油。下面简单的介绍一下冷油法洗萘工艺。

　　At present, the process of naphthalene washing with oil adopted by coking enterprises is generally divided into two types. One is the final cooling of naphthalene washing by oil at the same time of gas cooling and naphthalene washing, which is called cold oil naphthalene washing. The other is washing naphthalene with oil before final cooling, which is called hot oil washing naphthalene. The absorbent used for naphthalene washing is usually tar wash oil produced by our factory. The following is a brief introduction to the cold oil washing naphthalene process.
                

　　鼓风机后的煤气经电捕焦油器进入横式冷却管束及浮阀塔盘组成的终冷洗萘塔，在此煤气由45℃左右被冷却至25℃左右，同时煤气中大部分萘被清除。

　　The gas after the blower enters into the final cold washing naphthalene tower composed of horizontal cooling tube bundle and float valve tray through electric tar precipitator, where the gas is cooled from about 45 ℃ to about 25 ℃, and most naphthalene in the gas is removed.

　　由于冷却温度低于初冷后煤气露点，故在洗萘的同时，有水汽冷凝进入洗萘油中。

　　Since the cooling temperature is lower than the dew point of the gas after primary cooling, water vapor condenses into the naphthalene washing oil while washing naphthalene.

　　来自粗苯工段温度为28℃-30℃的脱苯贫油，由塔顶一块塔盘进入洗萘段，通过浮阀塔盘与煤气逆流密切接触以吸收煤气中的萘，然后进入装有横管式冷却管束的冷却段。在被煤气冷却的同时，油与煤气再次在管束外壁接触，并冲洗凝结在管壁上的萘。氨油流至塔底，成为含萘含水分富油。然后自流经加热器至85-90℃，进行加热破乳，再送至三个串联的脱水槽进行脱水。脱出的分离水直接或经分离水槽兑入富氨水槽中。脱水后的含萘富油兑入洗苯富油中。脱水槽排出的乳化物经乳化物槽送往粗苯工段的地下放空槽。为提高油水分离效果，还在一、二脱水槽中加入适量的清水。

　　The lean oil from crude benzol section with temperature of 28 ℃ - 30 ℃ enters naphthalene washing section from a tray at the top of the tower. It is in close contact with the gas countercurrent through the float valve tray to absorb naphthalene in the gas, and then enters the cooling section with horizontal tube cooling tube bundle. While being cooled by gas, the oil and gas contact with each other again on the outer wall of the tube bundle, and the naphthalene condensed on the pipe wall is washed. The ammonia oil flows to the bottom of the tower and becomes rich oil with naphthalene and water. Then, it is heated to 85-90 ℃ by self flowing heater, and then sent to three dehydration tanks in series for dehydration. The separated water is directly or through the separation tank into the ammonia rich water tank. The dehydrated naphthalene rich oil is mixed into the benzene washing rich oil. The emulsion discharged from the dewatering tank is sent to the underground vent tank of crude benzene section through the emulsion tank. In order to improve the effect of oil-water separation, appropriate amount of water is added into the first and second dewatering tanks.

　　冷油法洗萘工艺特点：连续洗萘；洗萘富油连续脱水和再生；煤气的终冷却和洗萘在同一设备中进行；洗萘操作处于较低的温度。因而洗萘效果较好。

　　The features of cold oil naphthalene washing process are as follows: continuous naphthalene washing; continuous dehydration and regeneration of rich naphthalene washing oil; final cooling of gas and naphthalene washing are carried out in the same equipment; naphthalene washing operation is at a low temperature. Therefore, the effect of washing naphthalene is better.

　　影响洗萘效果的因素。

　　Factors affecting the effect of naphthalene washing.

　　一， 洗萘的操作温度。当循环油含萘一定时，温度越低，则与其平衡的煤气含萘量越少；当煤气中含萘量一定时，温度越低，则允许的循环油含萘浓度越高。因此，降低洗萘的操作温度，有利于提高油洗萘效率。洗萘操作温度也不应过低，入塔循环洗油温度比煤气露点温度高10℃左右。

　　1、 The operating temperature of naphthalene washing. When the naphthalene content in the circulating oil is constant, the lower the temperature is, the less the naphthalene content in the balance gas is; when the naphthalene content in the gas is constant, the lower the temperature, the higher the allowable naphthalene concentration of the circulating oil is. Therefore, reducing the operating temperature of naphthalene washing can improve the efficiency of naphthalene washing. The operating temperature of naphthalene washing should not be too low. The temperature of circulating washing oil entering the tower is about 10 ℃ higher than that of gas dew point.

　　二， 煤气温度。为减轻洗萘塔的负荷，尽可能降低入塔煤气的含萘量，则需要控制好入塔煤气温度。首先，应控制好初冷器的操作，使初冷器后煤气集合温度低于25℃。

　　2、 Gas temperature. In order to reduce the load of naphthalene washing tower and reduce the naphthalene content of the gas entering the tower as much as possible, it is necessary to control the temperature of the gas entering the tower. First of all, the operation of the primary cooler should be controlled to make the gas collection temperature after the primary cooler lower than 25 ℃.

　　三， 洗萘油质量。洗萘油质量是影响洗萘效果的重要因素。对不同工艺的洗萘油质量有不同的要求。以冷油法洗萘为例。根据多个焦化企业的经验，我国焦化企业已经形成了一套质量标准。具体如下：

　　3、 Quality of naphthalene washing oil. The quality of naphthalene washing oil is an important factor affecting the effect of naphthalene washing. There are different requirements for the quality of naphthalene washing oil with different processes. Take naphthalene washing with cold oil as an example. According to the experience of many coking enterprises, a set of quality standards has been formed in China's coking enterprises. The details are as follows:

　　油洗萘质量标准

　　Quality standard of naphthalene in oil washing20℃时密度：≤1.07kg/g，黏度E25≤1.7，270℃前馏出量：≥50%，300℃前馏出量≥85%。

　　At 20 ℃, the density: ≤ 1.07kg/g, the viscosity e25 ≤ 1.7270 ℃, the distillation amount before 70 ℃ and the distillation amount before 300 ℃ are more than or equal to 85%.

　　以上内容是关于煤气中萘的清除方法，希望对大家有所帮助，如您想要选购精萘，了解具体精萘价格欢迎咨询我们的网站。

　　The above content is about the removal method of naphthalene in gas, hope to help you, if you want to buy refined naphthalene, understand the specific refined naphthalene price, welcome to consult our website.