氬餾分從上塔抽出后,進(jìn)入粗氬塔用精餾法進(jìn)行氧、氬分離。一般粗氬塔頂引出的粗氬組分為:氬大于98%、氮小于0.5%、氧小于1.5%。將純度大于98%的粗氬導(dǎo)入分子篩吸附器。每組吸附器設(shè)置2臺(tái),一臺(tái)吸附器內(nèi)裝5A分子篩,吸附粗氬氣中的氮;另一臺(tái)吸附器內(nèi)裝4A分子篩,吸附粗氬氣中的氧。
After the argon fraction is extracted from the upper tower, it enters the crude argon tower for oxygen and argon separation using distillation method. Generally, the components of coarse argon extracted from the top of the coarse argon tower are: argon greater than 98%, nitrogen less than 0.5%, and oxygen less than 1.5%. Introduce crude argon with a purity greater than 98% into the molecular sieve adsorber. Two adsorbers are set for each group, with one adsorber containing 5A molecular sieve to adsorb nitrogen from coarse argon gas; Another adsorber is equipped with 4A molecular sieve to adsorb oxygen from crude argon gas.
為了吸附劑的解吸,吸附器需要設(shè)置兩組,切換使用。吸附器在90K溫度條件下工作,粗氬氣入5A分子篩吸附器除氮,然后進(jìn)入4A分子篩吸附器除氧,其流程見圖18。從一組分子篩吸附器出來(lái)的氣體含氬純度可達(dá)到99.99%,即為純氬。
In order to desorb the adsorbent, two sets of adsorbers need to be set up and switched for use. The adsorber operates at a temperature of 90K. The coarse argon gas first enters the 5A molecular sieve adsorber for nitrogen removal, and then enters the 4A molecular sieve adsorber for oxygen removal. The process is shown in Figure 18. The gas from a group of molecular sieve adsorbers can have an argon purity of 99.99%, which is pure argon.
吸附法制氬的優(yōu)點(diǎn)在于,工藝流程簡(jiǎn)單、操作方便、成本低。但是,氬的純度只能達(dá)到99.99%。由于受分子篩選擇吸附能力的限制,無(wú)法獲得純度為99.999%。A的高純氬氣。另一個(gè)缺點(diǎn)是,吸附器的工作溫度為90K,再生溫度為423K,吸附結(jié)構(gòu)設(shè)計(jì)較為困難。
The advantages of adsorption method for argon are simple process flow, convenient operation, and low cost. However, the purity of argon can only reach 99.99%. Due to the limitation of the selective adsorption capacity of molecular sieves, a purity of 99.999% cannot be obtained. A's high-purity argon gas. Another disadvantage is that the working temperature of the adsorber is 90K, and the regeneration temperature is 423K, making the design of the adsorption structure more difficult.
吸附器工作時(shí),床層必須冷卻,往往需采用夾套或管內(nèi)通液氧冷卻。若想達(dá)到均一的冷卻溫度,對(duì)于大型制氬設(shè)備所需直徑較大的吸附器來(lái)說(shuō),就十分困難。因?yàn)橛幸陨蟽蓚€(gè)缺點(diǎn),限制了吸附法制純氬的應(yīng)用。目前,國(guó)內(nèi)吸附法制氬能力不超過10m3/h,只在150m3/h空分設(shè)備配套的制氬設(shè)備上采用,在大型制氬設(shè)備上尚無(wú)應(yīng)用。
When the adsorber is working, the bed layer must be cooled, often using a jacket or liquid oxygen cooling inside the tube. It is very difficult to achieve a uniform cooling temperature for larger diameter adsorbers required for large-scale argon production equipment. Due to the above two drawbacks, the application of adsorption method for pure argon is limited. At present, the adsorption method for argon in China has a capacity of no more than 10m3/h and is only used on argon production equipment matched with 150m3/h air separation equipment. It has not yet been applied to large-scale argon production equipment.