Page 360 - Centrifugal Pumps 2E

Chemical Pumps Metallic and Nonmetallic 325

• 15% is pulp and paper.
• The remaining is in aluminum, rayon, cellophane, petroleum, soaps,
and foods.

The elecrolytic plants produce chlorine and caustic soda using a range
of 250 to 1000 GPM and about 20 to 30 pumps. They also have 15 to 20
peripheral transfer pumps for hydrochloric acid, diluted H 2SO 4, and so-
dium hypochlorite. These plants use pumps of titanium, nickel alloys,
cast iron alloy 20, CD-4MCu, and nonmetallics such as vinyl ester.

Sodium-Hypochlorite

NaOCl is a byproduct of the chlorine and caustic process. It is found in
the bleach plants of paper mills with a concentration of 12% to 20%, in
commercial bleach such as household Chlorox, and OEMs for swimming
pool chlorination. The electrolysis of sea water (brine) with a concentra-
tion of 1 % to 3% is used for bleach plants, pulp mills, bleach plants for
textile mills, and municipal waste treatment to kill bacteria. These plants
use large amounts of sea water for cooling to prevent pipes from fouling
with algae. It is also used in the pretreatment of desalinization intake and
the pretreatment of secondary recovery brine in oil production. Pumps
are alloy 20, titanium, and nonmetallic.

Hydrochloric Acid—HCI

Also known as muriatic acid, it usually requires Hastelloy B or tita-
nium pumps. The primary consumption is pickling of steel for use with
oil well acidizing where acid increases the permeability of wells by dis-
solving part of the limestone and dolomite formations. High purity alu-
minum chloride produced by aluminum hydroxide and HCI is used in
pharmaceutical and cosmetic usage.
In food processing, HCI is used in the manufacture of sodium sluta-
mate and gelatin for conversion of cornstarch to syrup or adjusting the
pH value in breweries.

Sulfuric Acid—H 2 SO 4

With a 97% concentration, cast iron pumps are used. Eighty percent or
less concentration is either alloy 20 or vinyl ester nonmetallic pumps. It
has a very high boiling point, therefore a minimum loss is incurred at
elevated temperatures. It is an excellent drying agent in the manufacture
of chlorine gas. It is used for making fertilizers and explosives.