TM 55-1930-209-14&P-1
CHAPTER 9 CHLORINATION SYSTEM
Section I. General
9-1 General. Chlorination system generates a strong solution of sodium hypochlorite (commonly called chlorine for
treating water produced by the ROWPU's. Adding this to the water makes it safe for human consumption.
9-2 Description. The chlorination system produces chlorine in a sodium hypochlorite solution. A metering pump adds
this solution, upon demand, to water processed by the ROWPU system just before the water enters the four drinking
water storage tanks. The chlorination system's major components for Barge 1 are shown in Figure 9-1 and in Figure 9-2
for Barges 2 and 3. Major components are listed in Table 9-1. A chlorination system general working (block) diagram is
in Figure 9-3, and a system flowchart is in Figure 9-4. Equipment specifications, maintenance information, and
manufacturer's service manuals are in TM 55-1930-209-14&P-4.
9-3 Capabilities. The system generates and maintains a 5000 to 6000 ppm solution of chlorine and then meters this
solution into product water from the ROWPU system to obtain a chlorine concentration of 2 to 5 ppm in the drinking water.
9-4 Special limitations. For normal operation, the chlorination system requires seawater with a 3 to 4 percent salt
concentration. If the available seawater has a salt concentration less than this, see paragraph 9-13, to increase
concentration.
9-5 Performance characteristics
Production rate
40.5 gph
Holding tank capacity
310 gal
Approximate time to reach
concentration
4 hrs
Section II. Description of operation
9-6 General. The chlorination system generates and automatically maintains chlorine in the form of a sodium
hypochlorite solution with a strength of 5000 to 6000 ppm expressed as total available chlorine equivalent. This strength
is maintained by constantly recirculating the solution from the holding tank through a series of nine electrolytic cells and
back to the holding tank for a predetermined period of time. A metering pump draws chlorine from the holding tank and
injects it into product water flowing from the ROWPU's. This combination of product and chlorine flows through a mixer
just before the water enters the drinking water storage tanks. The mixer evenly distributes the chlorine throughout the
product water. A sensor measures the amount of chlorine in the treated water downstream of the mixer and causes the
metering pump to inject either more or less chlorine to maintain the amount of chlorine in the drinking water at 2 to 5 ppm.
As chlorine is withdrawn from the holding tank and the chlorine solution level drops, a float switch activates the brine
pump, which pumps brine solution from the brine tank to the holding tank. In the holding tank, the brine solution is mixed
and circulated with the chlorine solution from the electrolytic cells. When the level of chlorine solution in the holding tanks
reaches the proper level, the float switch turns the brine pump and circulating pump off. This process of recirculating and
replenishing continues as long as the chlorination unit and brine pump are activated and the metering pump withdraws
chlorine solution from the holding tank. On/Off operation of the metering pump is controlled by a flow switch located in the
ROWPU product water line. When the metering pump motor controller is in the AUTO mode, this flow switch
automatically starts the pump when ROWPU product water is flowing and stops the pump when product water stops
flowing.
9-1
