TM 55-1930-209-14&P-4CHAPTER 2 DESCRIPTION OF OPERATION2-1 General. The chlorination system generates and automatically maintains chlorine in the form of a sodiumhypochlorite solution with a strength of 5000 to 6000 ppm expressed as total available chlorine equivalent. This strengthis maintained by constantly recirculating the solution from the holding tank through a series of nine electrolytic cells andback to the holding tank for a predetermined period of time. A metering pump draws chlorine from the holding tank andinjects it into product water flowing from the ROWPU's. This combination of product and chlorine flows through a mixerjust before the water enters the drinking water storage tanks. The mixer evenly distributes the chlorine throughout theproduct water. A sensor measures the amount of chlorine in the treated water downstream of the mixer and causes themetering pump to inject either more or less chlorine to maintain the amount of chlorine in the drinking water at 5 to 7ppm. As chlorine is withdrawn from the holding tank and the chlorine solution level drops, a float switch activates thebrine pump, which pumps brine solution from the brine tank to the holding tank. In the holding tank, the brine solution ismixed and circulated with the chlorine solution from the electrolytic cells. When the level of chlorine solution in theholding tanks reaches the proper level, the float switch turns the brine pump and circulating pump off. This process ofrecirculating and replenishing continues as long as the chlorination unit and brine pump are activated and the meteringpump withdraws chlorine solution from the holding tank. On/Off operation of the metering pump is controlled by a flowswitch located in the ROWPU product water line. When the metering pump motor controller is in the AUTO mode, thisflow switch automatically starts the pump when ROWPU product water is flowing and stops the pump when product waterstops flowing.2-2 Preparation for operation. Both the holding tank and the brine tank have to be primed before the system canprepare the chlorine solution. Either seawater or fresh water may be used to prime both tanks. If seawater is used, itmay be supplied from either the seawater pumps in void 2 starboard or from the cooling pump in void 2 port. Freshwater, if available, is obtained from the drinking water pressure set. Paragraph 3-5 gives details on priming the system.After priming, this system takes about 4 hours to produce a chlorine solution of the proper strength in the holding tank.The system can be placed in operation before this 4-hour period, but the metering pump will inject a larger amount ofsolution into the product water to raise the chlorine level to the proper concentration. If the system must start injectingchlorine into the product water as soon as the seawater and ROWPU systems are placed in operation, a commercialhypochlorite solution (household bleach) can be added to the holding tank to create a usable solution.2-3 Non-operating chlorination system . ROWPU barges have only one chlorination system. If this system cannot beoperated, arrangements must be made for an onshore water processing facility to add chlorine to the ROWPU bargeproduct water when the water comes ashore. To provide safe onboard drinking water during such a situation, water inthe reserve tank must be manually treated with chlorine according to instructions in TM 55-1930209-14&P-5 DrinkingWater System.2-1/(2-2 blank)
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
