The following describes the basis for the provision of brine system on-site hypochlorite generators as per the RFQ and Electrichlor Hypochlorite Generator’s Inc Manufacturer’s Description.
Chlorination Requirements
Brine Production Requirement:125,000 kg/d NaHOCl
Rating: 2 x 52kg/h of Equivalent Chlorine
Power at Rated Load: 2 x 216kW Brine/hypochlorite –
Flow Rate: 2 x 6500 l/h Hypochlorite Concentration: 8000 mg/l
Power Available 380V, 3 ph, 50Hz .
Electrichlor hypochlorite generators are skid mounted on an aluminum C channel base with powder coated, marine grade IP-54 (NEMA 4X) aluminum control and electrolytic cells cubicles. The hypochlorite required is derived from a saturated (260%) brine solution that is piped to each generator with softened water to dilute the brine solution to between 3 and 4%. The brine is then recirculated multiple times through the electrolytic cells to raise the hypochlorite concentration to 8000 mg/l. Because the temperature of the solution is raised with every pass, the heated solution is cooled in a titanium heat exchanger to below 250C to ensure maximum brine to hypochlorite transfer.
As Electrichlor hypochlorite generators are of the “Constant Flow” type, the brine in flow rate equals the hypochlorite out flow rate. The incoming saturated brine to each generator is piped from a salt saturator and the outgoing hypochlorite routed to a degas/storage vessel.
Electrichlor recommends that the degas tank/storage vessel be a nexus lined, FRP, cone bottom tank(s) to mitigate precipitate build up. The degas/storage tank(s) are supplied with ambient air from redundant blowers to lower the hydrogen/air mixture to 5% of the “Lower Explosion Level”
A common Local Control Panel (LCP) houses a GE-Fanuc PLC with Versamax I/O and is equipped with an Operator’s touch screen for each generator. A Motor Control Center (MCC), supplies electric power to each generator and their common skid mounted pumps and blowers. An I/O cubicle is also provided for installation adjacent to the MCC to integrate the MCC equipment with the control system. As RO water is used for the process, there will be minimal calcium and magnesium build up in the electrolytic cells. However, to ensure that any build up does not cause the cell efficiency to drop, a fixed acid cleaning system has been provided. It is recommended that an acid clean be carried out on each generator on a monthly basis until the extent of the buildup is known.
2.1 Hypochlorite generators, equipped as follows
• Polyethylene powder coated marine grade Aluminum equipment skid
• Powder coated marine grade aluminum NEMA 4X cell cabinet and electrical control cubicle housing remote GE Versamax I/O for each generator control
• Emergency stop push button
• Electrichlor 4000A electrolytic cells
• A non flammable liquid immersed 4200A, 6 pulse transformer/ rectifier
• Schedule 80 CPVC piping for pressures greater than 3 Barg and schedule 40 UPVC for pressures below 3 Barg
• Titanium core hypochlorite heat exchanger
• Redundant hypochlorite circulating pumps
• Redundant chilled water pumps 2.2 Auxiliary Equipment
• Hypochlorite generators “Local Control Panel” housing a 12” Quick-panel Operator’s touch screen for each generator and a GE-Fanuc PLC with Versamax I/O
• Motor Control Center with motor starters as shown on the Single Line Diagrams
• A marine grade aluminum “Brine Pumps Skid” complete with 3 mag-drive pumps, with composite housing and impeller
• A skid mounted, 1500 liter HDPE acid cleaning tank and acid pump with a kynar body and impeller • Unpacking & Installation Instructions
• Brine tank with level transmitter (4-20mA
Hypochlorite degas/storage tank(s)
• Hypochlorite pump skid with redundant (2) mag-drive pumps, with composite housing and impeller
• Equipment unloading and placement
