Figure 7-11.Motor driven hypochlorinator with fully automatic control.
For emergencies, a standby alkali absorption
system with a suitable tank should be provided. The
alkali should be stored so a solution can be readily
prepared. Chlorine should be passed into the solution
through a suitable connection properly submerged and
weighted to hold it secure. DO NOT IMMERSE
CHLORINE CONTAINERS IN SOLUTION. Table
7-1 shows a chemical equivalent. Try to use quantities
in excess to allow absorption.
To prevent accidents caused by the corrosive
action of hypochlorite solutions, use vitreous crocks or
steel tanks lined with rubber or chlorine-resistant
plastic as solution containers. Store calcium
hypochlorite in a dry, cool location, and keep the cans
sealed. Wear rubber gloves and protective aprons
when preparing and handling hypochlorite solutions.
The liquid CO, recarbonization system uses
carbon dioxide gas to lower the pH of softened and
settled potable water. This unit is designed for
operation between -10°F and +3°F that corresponds to
pressure of 242.8 psig and 306.8 psig. The pressure
vessel is designed for temperatures as low as -20°F and
up to 350 psig. The unit comes with or without a
vaporizer, depending on the quantity of CO, required.
(If large amounts of CO2 are removed, it is possible to
cause the temperature to go below -20°F.)Once the unit
is installed and in proper operation, it requires little
attention. At the beginning and end of each day, the
operator should check the pressure and liquid level
gauges. The supply valve should be turned off when
the unit is not in use. The standard unit is equipped with
Table 7-1.Recommended Alkaline Solutions for Absorbing Chlorine