Nitric acid unloading 1

[BBMM]

Can air or N2 be used to unload 67% nitric acid from truck to an atmospheric storage tank or do trucks normally have their own pumps?

Can magnetic pumps be used to unload a truck, what metallurgy? Whats best way to unload?

 

[kenvlach]

Any info here about offloading doesn't matter, ask your supplier.

My 2 cents: Bulk acid deliveries I've received were from self-unloading trucks.

Magnetic pumps: The only magnetic drive pumps I've seen had the fluid side of the coupling encased in Teflon -- low friction & chemical resistant. Have never seen one large enough to be relevant for unloading a truck. Is there some other type of magnetic pumping?

Pumping nitric: Have used plastics (PVC, PP), Teflon-coated, 316 SS, ceramic (aluminum oxide) and even aluminum (pump housing only). Just thoroughly rinse pump & hoses afterwards.

 

[unclesyd]

We load and unload approximately ten trucks of 65% HNO3 per day. All loading and unloading is done with stationary pumps at the unloading station. No air or N2 is allowed to assist in the process. We do all the pumping, even though a few trucks have pumps on board. The pumps are in a diked area while the flex lines to the trucks are in an area whose drain is connected to a sump that is in turn connected to a process waste line. All piping is 304L SS and the pumps are 304 SS or HNO3 resistant alloys. The flex lines are Teflon Lined with SS braid. The is no CS around this area.

There is a fairly elaborate vent system to capture any NOX generated in the process.

 

[BenThayer]

unclesyd is right. i'll second it with regards to contacting your supplier. they can help with arranging the proper trucks.

there are lots of mag drive/sealless pumps that are big enough to unload nitric acid trucks and i would not use any of them. for systems that are not suction flooded all the time, they are too easy to start "dry" and ruin them. they are much more appropriate in continuous processes (had them when i used work at a site that manufactured nitric acid). we had the mag drive (Kontros) to make the acid but used conventional sealed pumps (Durco) for loading the acid. we were loading up to 10 trucks per day.

hmmm, unclesyd, we might have almost known each other.

for MOC, use 304L and do not use aluminum. i have never been a fan of plastic for volumes of this size.

some trucks can take some pressure to help get the acid to an unload pump but then special precautions should be taken to stay below the set pressure of the relief device on the trailer. these are sometimes 20-30 psig rupture discs.