Changing times and regulations mean changes in the way municipalities treat water and wastewater.
Typically, the plants use sodium hypochlorite to kill bacteria in the water and Finish Thompson DB or SP pumps are used to transfer the chemical from storage tanks to day tanks. This means handling and storing concentrated sodium hypochlorite, which can become diluted over time if stored for long periods of time.
Recently many plants have started using on-site sodium hypochlorite generation systems. These generation systems use a brine solution and electrolysis to generate sodium hypochlorite at about 1% concentration, which is a lower concentration than they had been storing. The plant makes the sodium hypochlorite as needed instead of storing large amounts of concentrated chemical, preventing the dilution that can occur with long periods of storage. Even though on-site sodium hypochlorite generation systems have been around for a while, they are becoming more accepted and are beginning to be specified for new and upgraded water treatment plants (WTP) and waste water treatment plants (WWTP).
Even though these plants are not having concentrated sodium hypochlorite delivered, there are still applications for Finish Thompson pumps associated with these systems. Once the generation systems make the sodium hypochlorite, it needs to be transferred to a tank that allows the hydrogen gas by-product to be vented. FTI mag-drive pumps are used to transfer the sodium hypochlorite generated by these systems to tanks to be vented and stored for short periods of time rather than the standard transfer from rail cars to long term storage tanks.
Finish Thompson DB Series pumps are a perfect fit for this application. The pumps can be supplied in PVDF material with PTFE bushings to be chemically compatible with sodium hypochlorite. Because these systems can require flows as high as 100 gpm and as low as 20 gpm from the same pump, DB Series pumps have the best curve profile for these varying flows. Many times the pumps will be operated by a variable frequency drive (VFD) to control pump speeds in an effort to maintain a specific flow rate during chemical transfer to keep the venting tanks at a constant level.
The DB Series pump models also offer features like vapor seals to protect the drive magnet assembly, our Easy Set outer drive, and a 5-year manufacturer’s warranty. As these systems become more prevalent in the water treatment industry, Finish Thompson mag-drive DB Series pumps should be considered a go-to pump in these installations.
Finish Thompson DB Series brochure, download here