Liquid ammonia heater
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Gentlemen! I wonder if all liquid ammonia heaters use steam for heating? Are there any modifications that involve using demineralized water or direct heat exchange with hot ammonia? Our facility uses steam for heating, but it seems like there is a waste of steam; is it possible to use hot ammonia for direct heat exchange with it?
To what extent is steam a relatively cost-effective heating medium? With your current equipment, it definitely won’t be sufficient for heat exchange using ammonia
The gas cylinder is immersed in hot water to vaporize, then superheated with steam, and finally condensed.
Normally, the amount of liquid ammonia used is 25 tons. There is no material balance sheet for the steam; the steam pipes are 8 inches in diameter, and their opening degree is around 13%, so the amount of steam produced should be around 3 tons. I haven’t calculated it, nor do I intend to, because steam is used continuously, which seems a bit wasteful. Therefore, I’m thinking of using condensate or hot ammonia for heat exchange with it, to see if there are any modifications that can be made, or to discuss possible better solutions
I’m sorry, I didn’t understand. In our facility, liquid ammonia at -40°C is heated to around 15°C using steam before being sent to the urea production process. It seems that both the cold energy and the steam are being wasted, so we want to save this amount of steam. It is also possible to recover cold energy at the same time
It is best to recover the cooling capacity; ammonia synthesis and urea plants should have process stages that require cooling.
If it is inconvenient to recover cold energy due to the distance of the on-site equipment or other reasons, steam condensate can be used for heating, thereby saving 3 tons of steam.
Most of the general condensate is sent to the desalinated water system, and this desalinated water is then used in boilers where it needs to be heated. After heat exchange with liquid ammonia, its temperature is relatively low, so additional heating is required, which also consumes energy. I just don’t know if it’s worth it.
Please verify what the temperature requirement is for the process condensate flowing into the desalinated water
I’m not sure about this; issues such as whether the diameter of the outlet condensate pipeline needs to be increased after switching to condensate require calculations, but I don’t have the expertise for that. So, I hope everyone can help