兩塔變壓吸附循環中兩步均壓的研究

曹永正　劉應書

摘 要 為了進一步利用吸附塔產品端的富氧氣體，提高氧氣回收率，減少單位氧產量的能耗，設計了一種新的兩塔變壓吸附均壓方式，即把均壓分為兩個小步驟，第一步實現產品端均壓，第二步實行產品端與進氣端均壓，每步均壓前有一小段保壓時間.為此建立了一套產氧規格為5 Nm3/h的制氧設備對這種均壓方式進行詳細的研究.試驗結果表明：在本文所述試驗條件下，當第一次保壓時間與第二次保壓時間分別為0.3 s和1.2 s，第一步均壓時間與第二步均壓時間分別為0.5 s和2.4 s，氧氣濃度維持在93.5%左右且環境溫度與濕度基本不變時，與單純的產品端均壓相比，兩步均壓使氧氣回收率增加了4.9%.采取兩步均壓方式，吸附階段吸附塔產品端氧氣濃度隨時間非常緩慢地減少，27 s時間內氧氣濃度下降值僅為0.61%，形成了類似于激波的濃度波，產品氧氣的濃度非常穩定.

關鍵詞 變壓吸附；兩步均壓；制氧；類激波

中圖分類號 TQ028 15文獻標識碼 A文章編號 10002537（2016）02005306

The Study of the TwoStage Pressure Equalization Step in the TwoBed PSA Cycle

CAO Yongzheng1，2*， LIU Yingshu1

（1.School of Mechanical Engineering， University of Science and Technology Beijing， Beijing 100083， China；

2.R&D Center， Jiangsu Oxtek Gas Equipment & Technology Co.， Ltd. Danyang 212300， China）

Abstract In order to use the oxygen enriched gas of the product end， improve oxygen recovery， reduce energy consumption， we designed a new twobed pressure swing adsorption pressure equalization step. It was divided into two phases， the first stage was to made the oxygen enriched gas enter the product end of the low pressure bed and the second process was to made the oxygen enter into the feed end of the low pressure bed from the product end of the high pressure bed. Additionally， a 5 Nm3/h oxygen equipment was built to study the twostage pressure equalization step. The research results showed that when two phases were 0.5 s and 2.4 s lasted respectively and before every stage there was a dwell time and the first time was 0.3 s and the second time was 1.2 s and the oxygen concentration was about 93.5%， the oxygen recovery using the twostage pressure equalization step was 4.9% higher than that of the product end pressure equalization step. The oxygen concentration in the product end dropped very slowly with a rate of only 061% in 27 s， and a similar sharpwave can be shaped when the twostage pressure equalization step was used.

Key words pressure swing adsorption； twostage pressure equalization step； oxygen concentration； similar sharpwave

變壓吸附循環包括原料氣升壓、吸附、均壓降、逆向放壓、反吹、產品氣升壓和均壓升等幾個基本步驟，通過對這些步驟的組合或重疊來實現循環的優化，以提高產品氣的回收率并減少系統能耗[1].在以往理論優化分析[15]中，對反吹程度[1，67]研究較多，均壓步驟完成后則被視為兩塔壓力均等.楊健等人[7]通過試驗對各種均壓方式進行了研究，其結果顯示產品端均壓比產品端與進氣端均壓更為有效，但楊彥鋼等……