Issues regarding the heating and cold blowing of molecular sieves
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I would like to ask everyone: why is it necessary to consider the lowest temperature when heating a molecular sieve, and the highest temperature when cooling it? What determines these temperatures? And also, why does the lowest temperature sometimes reach negative values during heating?
The switching systems of purifiers are designed based on the properties of the molecular sieves used. In terms of temperature, it refers to the temperature changes that occur during the desorption process of the molecular sieves; additionally, such systems function as energy storage devices as well. Try to understand it from these aspects.
What I understand is that during heating, high-temperature contaminated nitrogen exchanges heat directly with the molecular sieve to undergo desorption. However, contaminated nitrogen is unsaturated and can absorb water molecules, which raises its temperature. What I don’t understand now is why the temperature of the contaminated nitrogen gas becomes negative at times when it exits the molecular sieve; moreover, it seems that a negative temperature is necessary to indicate that thorough desorption has taken place
What I understand is that the hot contaminated nitrogen gas exchanges heat directly with the molecular sieve to undergo desorption, but since the contaminated nitrogen gas is unsaturated, it absorbs water molecules, which raises its temperature. What I don’t understand now is why the temperature of the contaminated nitrogen gas drops to negative values after passing through the molecular sieve; moreover, it is only when the temperature is negative that it can be said that the molecular sieve has completed the desorption process thoroughly
The changes in adsorption and desorption temperatures are opposite.
What criteria are used to determine the lowest temperature for heating? Are there any parameters?
This post was last edited by CHANGBAISHI on 2019-2-14 08:34. The \"minimum heating temperature\" and other temperature settings are determined based on the characteristics of the molecular sieve. Moreover, your question should focus on the conditions under which the molecular sieve is used; it seems that your question isn’t about the actual measured temperature values, but rather relates to other temperatures ? ? It is recommended to mention the issue in relation to the location of the side point. Additionally, the adsorption of molecular sieves is an exothermic reaction, while desorption is an endothermic reaction.
Yes, thank you very much. Can it also be said that the amount of molecular sieve determines the lowest heating temperature?
The decomposition is an endothermic reaction; at the beginning of heating, heat has not yet been transferred, so the outlet temperature decreases. Whether the regeneration of molecular sieves is complete is generally determined by the cold blow peak, which in turn is determined by the temperature of the regenerating gas and the load on the molecular sieves.