Water Connections: Metering a High-Pressure Alum Application
Water treatment plant uses a dual diaphragm pump with chemical feed sensor for a high-pressure alum application.
By Amparo Burke
SUEZ Water South Jersey is located in Toms River, N.J. Its mission is to provide safe and clean water to the Township of Toms River, Borough of South Toms River, and a portion of the Township of Berkeley.
SUEZ is a leading environmental company that takes pride in integrating sustainability into its business practices for the communities served. Water and wastewater management provided to South Jersey is designed to optimize economic considerations while also meeting or exceeding all regulatory requirements.
The Water Treatment Plant in Toms River needed to precisely meter a low concentration of alum at a high pressure. Alum is a chemical compound that is a hydrated double sulfate of aluminum and potassium used to remove turbidity. When used effectively, alum will keep the water clear by removing color and suspended particles.
SUEZ is using several ProSeries-M® model M-3 peristaltic metering pumps to inject various chemicals into the water system. The employees prefer peristaltic metering pumps because of their ease of use with SCADA systems. However, there had been concern that the amount of pressure needed to inject the alum would be too high for use with M-3 peristaltic style pumps, possibly resulting in decreased tube life and, thus, the need for numerous tube replacements.
The solution was to employ the Pro-Series-M® MD-3 Dual Diaphragm Metering Pump, which can be used successfully in high-pressure applications. The MD-3 mimics the traits of a peristaltic metering pump but since there is no tubing, there is no concern of increased maintenance.
Single diaphragm metering pumps have a suction phase and a discharge phase, which results in an intermittent flow. However, the dual diaphragm configuration of the MD-3 metering pump means that when one diaphragm is in the suction phase, the second diaphragm is in the discharge phase. This helps the chemical to be injected in a near continuous flow. And the MD-3 SCADA is identical to that of the M-3.
In addition to the MD-3 metering pumps, SUEZ also installed the ProSeries-M® MS-6 chemical feed sensor. The sensor closely tracks chemical being fed into the system, making certain the proper amount is being injected. Data advising the exact flow rate that is being metered goes directly from the MS-6 to the SCADA system. The MS-6 gives a precise measurement of chemical metered so that proper dispensing/dosing can be easily verified.
SUEZ successfully injects a low concentration of alum at high pressure using the Proseries-M® MD-3 dual diaphragm metering pump, and there is never a need for tube replacement. In addition, by installing the MS-6 feed sensor, SUEZ is able to quickly verify the exact amount of alum being injected into its application, and that information is automatically sent to the SCADA system. With this improvement SUEZ continues to standardize its chemical systems by optimizing both equipment and functionality to meet operational needs. WW
Blue-White Industries is exhibiting at WEFTEC.19, booth 3425. Learn more at www.blue-white.com.