Concentrated Sulphuric Acid

• Quantity:                14,686 lbs/hr     6,661 kg/hr 
• Concentration:        93%  wt. min. 
• Temperature:          360° F              182° C

Effluent Gas

• Quantity:                3 ACFM           5 m³/hr    
• Temperature:         74°  F                23° C    

Process-Condensate

• Quantity:                14,013 lbs/hr      6,356 kg/hr   

Steam

• Quantity:                7,982 lbs/hr     3,620 kg/hr 
• Pressure:                285 psig          20 bar g 
• Temperature:          417° F            214° C

Condensate

• Quantity:                7,982 lbs/hr     3,620 kg/hr
• Pressure:                100 psig          7 bar g 
• Temperature:          338° F            170° C    

Cooling Water

• Quantity:                500 gpm          113.6 m³/hr
• Pressure:                70 psig             5 bar g 
• Temperature-in:      60° F               15.5° C   
• Temperature-out:    82° F               27.8° C    

Insturment Air

• Quantity:                0.8 ACFM     10 Nm³/hr
• Pressure:                100 psig         7 bar g 
• Temperature:          86° F             30° C

Electric Power

• Rated power for motor:  81 hp
• Rated power for control panel:  6kw

The plant is built to re-concentrate 72% sulphuric acid with a capacity of 19,000 lbs/hr up to 93% suphuric acid.

Hot spent sulphuric acid is fed from the external plant to the circulation loop of the first stage.

A forced circulation evaporation process is used with  the steam heated heat exchanger
(E 502).  Water is evaporated, whereby pre-concentrated sulphuric acid of about 85% H₂SO₄ is produced.  The vapours and non-condesable gases are sucked off by the vacuum pump (C 511) which is simultaneously used for the other concentration step, and the vapours are fed to the vapour line.

From the first stage evaporator (R503) the acid runs over to the second stage.

A part stream of the circulation loop is used to wash the vapours in the purification column
(A 504) of second stage to minimize the acid content in the condensate.

The second stage is a steam heated horizontal evaporator (E 506 / R 505).  The acid is concentrated up to its final concentration of minimum 93 wt % H₂SO₄.  The vapours leave the evaporator and are led to the purification column (A 504).

The final concentrated acid flows over to the dip and buffer tank (T 507) and is pumped by
(P 508) to the tank farm.

The vapours of the first and second stage are combined and condensed in condenser
(E 509), after being de-superheated.  The common condensate flows over to the dip tank (T 510) from where it is overflowing to an external treatment.

The non-condensable gases are sucked off by vacuum pump C 511.