C-01 What is the reason for the sudden drop in the temperature of liquid A when flushing with ammonia water when the temperature of the fine washing section is high?

Is there any vaporization phenomenon that causes the temperature to drop?

This problem applies to the medium-pressure absorption tower in the ammonia stripping process and the aqueous solution process. The principles are similar. Let’s talk about the ammonia stripping process. reason: 1 There is methylammonium liquid crystallization on the tray in the C-01 fine washing section, which increases the resistance drop of the tray. There is liquid accumulation on the tray (usually a bubble cap tower), which is a sign of the early stage of liquid flooding. 2 C-01 uses refluxing ammonia to absorb CO2 and distill NH3, but methylammonium does not dissolve liquid ammonia (unless it is above 115°C) and is easily soluble in ammonia water. 3. During ammonia flushing, methylammonium dissolves, and the tray resistance decreases and the accumulated liquid flows down quickly. However, the temperature of the accumulated liquid is relatively low, causing the bottom temperature to drop and the liquid level to rise at the same time. The methylammonium liquid delivered by the dimethyl pump is forced to turn down. deal with: 1. Control the outlet temperature of E-06 to the normal index and do not over-temperature, which will increase the load on the medium-pressure absorption tower. 2. Control the liquid level of the gas stripping tower to prevent gas leakage. 3. Control the flow rate of reflux ammonia. 4 Regular flushing plus long-term flushing: The ammonia water at the top of C-01 maintains a certain opening ； Periodically flush the trays with ammonia or condensate for short periods of time. 5 C-01 controls the liquid level to 50% of normal, not too high or too low. other: If the tray is not well sealed and leaks or falls over, the system has to be shut down for maintenance. 1. If there is only liquid leakage, the amount of reflux ammonia can be increased to maintain the liquid level, but the load on the methylammonium pump will be heavy. 2. If the tray overturns, the only option is to lower the outlet temperature of the medium-pressure condenser and reduce the absorption load. This post was last edited by Boating Five Lakes on 2009-3-10 17:32 ]

The teacher on the third floor explained it in detail, but I still have some questions.: There are methylammonium liquid crystals on the tray in the fine washing section, which increases the resistance drop of the tray. Can it be understood this way?: The solid crystals of methylammonium blocked the tooth gaps of the bubble cap (lower gas channel), making it difficult for the lower gas to rise and increasing the resistance drop of the tray. This further affects the descending speed of the liquid in the downcomer, causing part of the liquid to remain on the tray, forming liquid flooding? Also, is the decrease in the temperature of the first liquid A related to the amount of reflux ammonia added? Generally, when the temperature of the fine washing section is high, we compare * If the flow rate of reflux ammonia at the top is increased, the tray resistance decreases after flushing with ammonia water, and part of the reflux ammonia reaches the bubble section along with the dissolved ammonium methane solution, resulting in an increase in the concentration of liquid 1A and a large N/C ratio. Part of the ammonia vaporizes from liquid 1A, which lowers the temperature?

The third floor said, "There is liquid accumulation on the tray. When flushed with ammonia water, the methylammonium dissolves, and the resistance of the tray is reduced. The liquid accumulation flows down quickly, and the temperature of the accumulation liquid is low, causing the bottom temperature to drop. ”I don't quite agree with this view. You must know that the bubble cap tower tray itself requires liquid accumulation. The liquid level on the tray must submerge the air outlet of the bubble cap to prevent the gas from short-circuiting and allowing bubble absorption. The liquid absorbed by bubbling flows into the next tray through the downcomer. The space of the downcomer is generally very large, and the increase in tray resistance will not affect the descent of the liquid. Why does the temperature of liquid A suddenly drop when flushing with ammonia? In fact, as long as you observe carefully, when the temperature of the first liquid A suddenly drops, the temperature of the fine washing section has already dropped first. In other words, the sudden drop in the temperature of the first liquid is caused by the temperature drop of the fine washing section. As Haiyou on the 4th floor said, when the temperature of the fine washing section is high, the dissolved amount of reflux ammonia in ammonia water is less. When the temperature of the fine washing section is reduced after treatment, the solubility of reflux ammonia in ammonia water increases. High-concentration ammonia water reaches the bubbling section, and the concentration of liquid ammonia increases, so the temperature drops.