2 replies to this topic

[P VENKATESWARLU]

We have liquid ammonia storage of 50000 MT at -33 deg C @ atm. we are using this liquid ammonia for manufacturing phosphatic fertilizers by reacting with phosphoric acid in prenutralizer. We are pumping liquid ammonia @ 15 kg/cm2g to Fertilizer plant. Before supplying to Prenutralizer we are preheating liquid ammonia to 0 deg C @ 5 kg/cm2g in preheater. Here we using saturated steam as heating media @ 3.5 kg/cm2g & 140 deg C. 

 

We have plenty of cooling tower return water from Ammonia cooling tower, Sulphuric acid plant cooling tower and Power plant cooling towers

 

As a energy conservation measure, can i use return cooling water as heating media for heating liquid ammonia instead of saturated steam in preheater. Any freezing problems , please suggest me

 

Thanks

 

[K RAVI VARMA]

In case water is used as a medium for heating liquid ammonia from -33 ^oC to +10 ^oC, during periods of low water flow or whenever water circulation pump is stopped, stagnant water in the ammonia preheater solidifies into ice, impeding further heat transfer. 50% ethylene glycol is therefore employed for preheating ammonia as its freezing temperature is -36 ^oC, thereby eliminating all chances of solidification of heating fluids due to freezing.

 

 

regards

Edited by K RAVI VARMA, 17 July 2015 - 01:45 AM.

[P VENKATESWARLU]

 

In case water is used as a medium for heating liquid ammonia from -33 ^oC to +10 ^oC, during periods of low water flow or whenever water circulation pump is stopped, stagnant water in the ammonia preheater solidifies into ice, impeding further heat transfer. 50% ethylene glycol is therefore employed for preheating ammonia as its freezing temperature is -36 ^oC, thereby eliminating all chances of solidification of heating fluids due to freezing.

 

 

regards

 

Thanks for your reply sir. We will take action accordingly