Design of 25% ammonia water storage tank
Thread Content
Our factory now needs an ammonia solution storage tank with 25% concentration and a capacity of 1,000 cubic meters. Is it possible to design a vertical, atmospheric-pressure storage tank? We would appreciate some advice from experts
At normal temperatures (below 60 degrees), vertical carbon steel flat-bottom arch top storage tanks are used, equipped with internal floating discs and nitrogen sealing.
Generally, a breathing valve needs to be added...
With current high environmental standards, it should be designed with a breathing valve; personally, I don’t think there’s a need for an internal floating disk. In fact, the value of the corrosion margin for this tank is quite critical, as it determines the thickness of the tank wall.
Firstly, I have never worked with ammonia solutions of such high concentration. The saturated vapor pressure at 25% concentration and 60°C seems to be difficult to determine accurately. For a storage tank with a flat-bottomed arch structure covering 1000 cubic meters, it is necessary to check whether the design pressure is sufficient to meet the requirements for such a large tank
The saturated vapor pressure at 25% concentration and 60°C appears to be around 0.2 MPa, which exceeds the design range for vertical cylindrical storage tanks; it is recommended to use a low-temperature storage tank with a temperature of around -30°C. Insulation should be applied to the outside of the tank, and the design pressure should be around 20 kPa, in which case it can be designed as a vertical cylindrical tank.