Is a high temperature in the outlet pipeline of the liquid ammonia transfer pump the cause of vaporization within the pump?
Thread Content
The cold ammonia delivered by the liquid ammonia pump has a temperature of -33°C. Before starting the pump, it had already been cooled down. However, once the pump was started and the outlet pressure showed normal levels, the outlet valve was slowly opened a little; immediately thereafter, the pressure at the pump’s outlet dropped sharply, and the pump began to vaporize. Is it possible that the high temperature in the outlet section is the cause of the pump’s vaporization? The temperature of the pump outlet pipe reached 20°C.
It shouldn’t be; the vaporization of liquid ammonia absorbs heat
The boiling point of ammonia is 33°C. The storage tank is not under pressure; the temperature in the outlet pipeline is high, causing the liquid ammonia to vaporize directly, which increases its volume. Due to the configuration of the outlet pipeline, this causes pressure to build up and push the liquid back. If there is a vent valve at the outlet, it should be opened to allow some of the liquid to escape, until the outlet temperature drops. Alternatively, adding backpressure to the liquid ammonia storage tank can also solve this issue