Steam heater

What you need is mainly temperature; it should not be allowed to introduce low-temperature polluted nitrogen gas first.

After the adsorption in a molecular sieve purifier reaches saturation at 0.5–0.6 MPa, it should be regenerated. The regeneration process is carried out in 4 stages: pressure relief, heating, cold blowing, and pressure charging. Regeneration is generally carried out at 10–15 kPa. During depressurization, water, carbon dioxide, acetylene, and other molecules adsorbed by the molecular sieve are partially desorbed. Since desorption requires energy, heat must be absorbed. This portion of the heat comes from the molecular sieve bed itself; therefore, as the bed temperature drops, the temperature at the gas outlet also decreases. During the heating phase, polluted nitrogen gas is typically used as the heating gas. Dirty nitrogen is heated through a steam heater or an electric heater. For the single-layer molecular sieve purifier, the temperature of the heating gas is 280–300℃ ； For the double-layer molecular sieve purifier, the heating temperature is 200°C. The heated gas enters the molecular sieve bed; generally, the gas enters from the top, heating the bed layers on the outlet side and in the middle, thereby causing the adsorbed impurities to desorb, and sufficient heat is stored within the bed layers. The outlet temperature of the contaminated nitrogen serves as the basis for operation. At the beginning of the heating phase, the heating gas raises the temperature of the molecular sieve bed near the air outlet, providing the energy necessary for the desorption of water and carbon dioxide; as a result, its temperature drops rapidly, with the temperature at the nitrogen outlet even falling to -10°C, before it begins to rise gradually. Stop heating when the outlet temperature of the polluted nitrogen reaches 100°C. The gas used during the cold blowing stage is still contaminated nitrogen, which is not heated again. Obviously, the temperature of the gas as it enters the molecular sieve bed will drop rapidly, and the temperature of the bed near the inlet side also decreases accordingly. As heat moves toward the dirty nitrogen outlet side, the bed on that side will continue to rise, and this portion of the molecular sieve will continue to be regenerated. The outlet temperature of the polluted nitrogen will also gradually increase, reaching a peak temperature of around 160°C, after which it decreases back to normal temperatures. This indicates that the molecular sieve has been regenerated and is ready for use. During the cold blowing phase, the outlet temperature of contaminated nitrogen may also exhibit two or three peaks, which is often due to unevenness in the molecular sieve bed of the purifier, with some areas being thin and others thick. During the pressurization phase, air is introduced into the purifier, causing the pressure inside it to increase. As impurities, moisture, carbon dioxide, and acetylene in the air are absorbed by the adsorption bed, the temperature rises; generally, the air outlet temperature increases by 2 to 4°C.

Analysis of the steam heaters in Nantong Jianghan Petrochemical: water is in a liquid state, while steam is a high-temperature gaseous substance. Once cold liquid comes into contact with hot steam, an explosion occurs, producing extremely loud noise. The advantage of introducing steam first is that it preheats the pipes, so the noise generated when water comes into contact with them is not as loud. When water turns into a gas, its volume expands by 200 times. Hope this helps you

You're talking about preventing boiling over~~ What's being discussed here is the issue of whether the cold flow or the hot flow comes first in heat exchange~~

After introducing steam, check whether there is condensed water on the dirty nitrogen side or if the dew point increases – this is to prevent dirty nitrogen from carrying water~~