Moving sulfuric acid by vacuum

[fitz]

I recently visited a power plant where the sulfuric acid, and maybe the caustic soda, too, was moved by vacuum from storage tanks to the demineralizer beds for regeneration of the resin. The engineer giving me the tour said his company didn't like pumping those liquids and had much better luck with using vacuum.

Has anyone else seen this done, and how do you do it?!

 

[cub3bead]

You use water eductors to create the vacuum and then dilute the chemicals to the desired concentration.

Watch out for the heat of dilution with sulfuric acid and caustic.

Also, you will need a pressure regulator on the water supply line. The purpose of this is to maintain constant supply pressure to the eductor. If your water source comes from a tank where the level could have large swings, then the flow through the eductor will be effected without a pressure regulator.

A hydrometer pot downstream of the dilution eductor is a good idea so your operators can confirm proper dilution.

 

[MikeJefferies]

Permutit Boby used to do this regularly in the 70s and 80s. They would use an eductor to suck the air out of the top of a pressure vessel, causing the regeneration chemical to flow into the vessel from the bottom. The chemical flow was stopped using a level probe in the tank.

When they were ready to produce the diluted regeneration chemical, the feed chemical was dropped into the regen tank, mixing with water in a funnel type arrangement.

This diluted chemical was then sucked into the regeneration flow using an eductor. The wole thing was termed a "vacuumatic" system, I think. I may have a P&ID at home somewhere if you are interested.

 

[saumian]

Fitz,

We do not use sulphuric acid, but we use aqua ammonia in our facility.

We have a 5000 US gal tank for storage of AA. The tanker truck brings AA and fill the storage tank in 30 minutes using Air compressor, and picks up used ammonia from our spent tank to the same tanker truck by vaccum.

We are considering to use transfer pump instead of air compressor for transferring AA due to ammonia vapour released inside the facility.

Saumian