Purification process: Both the heated gas and the cooled gas flow through the same pipeline – will this have any adverse effects?
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This post was last edited by jianyu2106 on 2011-9-8 09:51. In a small-scale, fully low-pressure molecular sieve purification process, since both the heating gas used for regeneration and the cooling gas flow through the same pipeline, what adverse effects might this have on the system’s equipment? The process was not clearly explained earlier; specifically, it works as follows: Before entering the molecular sieve, the regeneration gas pipeline has two paths in the conventional process – one is the gas that has been heated by a heater, and the other is the cold blowing gas, which enters the molecular sieve directly without passing through a heater ； But if both the heated air and the cooled air have only one flow path coming from the heater, could that have an adverse effect on the system?
It won’t have any impact on the system; the design calls for heating first and then cooling to ensure thorough regeneration of the molecular sieve.
It has no impact on the equipment; cold blowing is an additional stage that follows heating, during which the heat from the molecular sieve is transferred downward, resulting in a peak value at the outlet temperature. Additionally, since the heat is distributed evenly from top to bottom, there is no issue of large temperature differences, so it does not affect the purifier. . . If it had any impact, improvements would have been made long ago; this process has evolved over many years and represents a highly mature design. . .
It should have no impact on the equipment, but pay attention to the stress on this pipeline; if it is quite long, a telescopic compensator may need to be installed
In the design of molecular sieve purification systems, there are processes of this kind； After the heating of the molecular sieve is complete, a cooling phase begins; the residual heat from the electric heater is used to continue regenerating the molecular sieve, ensuring thorough regeneration and achieving the designed peak value for cooling ； As for stress compensation, this is taken into account in the design ；
The pressure of the nitrogen used for heating or cooling molecular sieves is only around 20 kPa; therefore, even though the temperature varies from -10 degrees to 180 degrees, the low pressure results in minimal stress on the equipment and pipelines, allowing the use of the same pipelines.
From a process perspective, there is no impact, but there are differences in terms of investment and energy consumption; since both heating and cooling take place through heaters, one control valve can be omitted, resulting in a more compact piping layout. However, the efficiency of heating and cooling will decrease, mainly due to the cycling process of heating and cooling in the heater, as well as the inertia associated with heat storage in the heater. If cooling is not sufficient to counteract heating, then this problem does not arise, and the heater remains in a high-temperature state. If the heater you use is very light, meaning it has low thermal inertia, you can consider sharing pipelines, such as by using an electric heater with an inlet.
Using the waste heat to continue heating results in a very high peak value at the molecular sieve outlet; this is an excellent design. Most equipment for opening containers follows this process. By ending the heating phase and switching to cold blowing, the time required for cold blowing can be reduced. Most Hangyang facilities use this approach
Another advantage of heating and cold blowing along the way is reducing pressure fluctuations in the tower
It doesn’t have much of an impact. If they share the same pipeline, then if the heater lacks a heat storage function when heating is applied, the temperature will rise more slowly; however, it’s not a significant issue
It seems that Brother Jiu Tian has explained it clearly enough – both the heating gas and the cooling gas travel through insulated pipelines, so it has no impact on the equipment