The City of Eagan in North Minnesota, USA required a pump capable of accurately dosing 15% sodium hypochlorite or ‘hypo’ for their new wastewater treatment plant.
Hypo has outstanding disinfection properties. It is used in wastewater treatment to kill off bacteria before being discharged back into the environment and in water treatment as one the primary methods of drinking water disinfection. It is also a challenging product to pump. This is because hypo tends to off-gas, causing some types of pump to vapour lock. Diaphragm pumps are particularly prone to this.
After evaluating several pump choices from a number of manufacturers, they decided on the Verderflex VF10 peristaltic hose pump for the job. The ten pumps will be put to immediate use in this new area of the treatment plant. Each Verderflex VF10 pump is capable of flow rates up to 48 US GPH and at pressures up to 175 psi. Verderflex pumps can pump both gas and liquid, ensuring the liquid stream receives a consistent dose.
Peristaltic pumps are the pump choice for dosing sodium hypochlorite and Verderflex pumps can be found in wastewater treatment plants worldwide.
The fluid being dosed is kept totally enclosed within the rubber hose which is then compressed by a rotating shoe forcing the liquid inside, along. Upon restitution of the hose the resulting vacuum draws in more liquid. This process is known as peristalsis and is what makes the peristaltic pump the first choice for liquid metering. Variations in hose type allow for low strength and even high strength hypo dosing.
Naturally the wastewater plant needs to run as cost efficiently as possible and the City of Eagan were impressed with the long life given by the Verderflex hose and the ease of maintenance when the hose needed to be changed.
“We were really pleased with the installation at the treatment plant. There were many other pumps considered for this application but in the end easy maintenance, proven reliability and exceptional hose life of the superior Verderflex design won out,” explained Tom Eisemon, National Sales Manager of GPM Pumps, the master distributor for Verderflex in the US. “As a result of this installation, a similar project located nearby chose Verderflex for these same reasons and a third customer in the state recently purchased a new Verderflex DURA after hearing all the positive feedback and the new features of this design. These pumps have certainly been a success for us in this industry.”