Ammonia cooler liquid level height
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These days, there has been a lot of discussion regarding the liquid level issue in ammonia coolers. After checking the drawings, I found that the interface positions for the liquid level gauges in these coolers are set quite high; the early drawings showed the same thing. If the liquid level is to be controlled at 1/2 to 2/3 of the tank’s height, that would account for almost half of the tank’s total height. Won’t this affect the evaporation area? What level do everyone aim to maintain?
In my opinion, the level gauge in the ammonia cooler is designed primarily to prevent excessive liquid levels from causing liquid slugging at the inlet of the chiller; it is better to operate without a level gauge in normal conditions.
As suggested above, removing the level gauge and replacing it with a high-level alarm switch would be more cost-effective
Hehe, an ammonia cooler still requires a liquid level, as this facilitates operation. If the level is too high, liquid ammonia may be carried out, leading to accidents in the chiller; if it’s too low, the temperature of the process gas won’t drop enough, resulting in poor separation efficiency, energy waste, and even a drop in temperature in the synthesis tower due to inadequate separation. One more thing I’d like to mention is that the cooling effect of an ammonia cooler relies mainly on the latent heat of evaporation of ammonia; the sensible heat contributes only a very small portion. Therefore, when discussing the cooling area, this aspect must be taken into account. :handshake
The ammonia cooler must have a liquid level; without it, the liquid ammonia will flash as soon as it enters, which reduces the heat exchange area. The liquid level can be adjusted according to process requirements.
For vertical ammonia coolers, under constant other conditions, the condensation temperature decreases as the liquid level rises (starting from the empty-level state); after reaching a certain height, it increases again as the liquid level continues to rise； In horizontal ammonia coolers, the liquid level generally exceeds that of the heat exchange tubes, and the height is limited; the liquid level has little relation to the condensation temperature. The purpose of level control is: 1. to achieve good condensation effects; 2. to absolutely prevent the presence of ammonia
Generally, maintaining a low liquid level of 20%–30% is sufficient; too high a level can lead to liquid carryover, while too low a level results in temperatures that do not meet the requirements.
The level gauge of the ammonia cooler is used to prevent liquid ammonia from reaching the ice machine, which could impair its normal operation; generally, the liquid level should be maintained at 20–30%.