Air separation oxygen production area: [Weekly Topic] Week 12 of 2011——Comparison between vertical and horizontal molecular sieves
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At present, most domestic large-scale air separation molecular sieves use horizontal molecular sieves, while foreign companies mostly employ vertical molecular sieves. Based on previous discussions by Haiyou, I have summarized the following key differences: Vertical molecular sieves occupy less space, utilize radial flow, have lower resistance, and ensure a more even distribution of gas flow； Horizontal molecular sieves require a large amount of space, and distributing the gas flow evenly presents a challenge. Over time, issues such as thickness reduction in the bed layer can occur, which affects the adsorption efficiency. The molecular sieves at the top layer are prone to becoming powdered, leading to blockages in the pipes. However, due to limitations in domestic technology, large-scale air separation units in China currently use horizontal molecular sieves. Please discuss the advantages and disadvantages of horizontal and vertical molecular sieves based on the actual conditions of your own facility. It would be helpful to cover the following aspects: 1. Length of adsorption time; 2. Time required for maintenance; 3. Temperature and moisture content before the gas enters the molecular sieves; 4. Regeneration temperature; 5. Operating pressure, etc
I have only worked with vertical molecular sieves, so it’s difficult for me to participate in the discussion
Horizontal molecular sieve adsorbers use molecular sieves from Shanghai UOP, and they also perform well. The main problem does not lie with the vertical and horizontal molecular sieve adsorbers, but rather with the choice of molecular sieve adsorbent
We’re using vertical models now, and they work quite well. The new set to be installed will use a horizontal type; I heard that using a vertical type would result in too high costs, so a horizontal type was chosen to reduce expenses. I wonder if it will work well?
Apart from uniform airflow distribution, low resistance, and high efficiency, the rest is related to the components installed
Vertical models have too high a cost; horizontal models are good as well, though they take up more space.
I have made many molecular sieves, both vertical and horizontal types. Those used for handling small volumes of gas are vertical type; the horizontal type is wasteful and results in high costs! Horizontal types are preferred for handling large volumes of gas; vertical radial flow technology is not yet mature, and there is no experience in operating such systems – customers should avoid domestic products! Small vertical types are not sufficient, while traditional large vertical types have too much resistance and cannot be used at all! Only the horizontal type can be used. The adsorption cycle is related to factors such as the properties of the molecular sieve, the volume of gas to be treated, pressure, and temperature. When the air contains high levels of moisture, the molecular sieve absorbs water and becomes difficult to regenerate, a condition commonly referred to as \"failure\"! Alumina should be used first to filter out water. Molecular sieves generally need to be replaced every two years. Molecular sieves operate under positive pressure at varying pressures.
I’ve never operated a horizontal model before; come and learn* learn* :)
In my opinion, compared to horizontal types, vertical types offer a more even airflow distribution but have higher resistance. The uneven airflow distribution in horizontal molecular sieves also leads to waste of the molecular sieves from another perspective. Other possibilities include the amount of space it occupies, and so on
Can someone give a specific explanation? I’ve asked many people about this, but no one has provided an accurate answer; most said there isn’t much difference!