Technology news10Filtration+Separation June 2007

Separation system prevents sewage blockages Pump expert Wilo has developed a new solids separation system for its EMUPORT sewage pump installations.

Currently, moist and moisturised cellulose tissues are amongst the most problematic items in municipal sewage disposal situations, Wilo says. When this material gets into a pump, the hydraulics can be often badly affected which can lead to the pump blocking, resulting in expensive maintenance at the pumping stations. If the primary pump becomes blocked, the standby pump can also break down for the same reason.

Wilo’s solids separation system works by ensuring that this material does not come into contact with the pumps during the pumping process. The system incorporates a solids separation reservoir through which all incoming sewage flows on its way into a collection reservoir. During the filling process, the pump remains switched off. The incoming sewage flows into the solids separation reservoir first

and the solids are held back by separating flaps, with only the liquid sewage flowing through the

switched off pump able to reach the collection reservoir. When the water reaches a certain level

in the two reservoirs, a shut off ball valve automatically closes the intake. At this stage, the filling process turns into a pumping process, in the opposite direction to the flow into the reservoir. The liquid sewage is pumped out of the collection reservoir through the solids separation reservoir and by so doing opens the separation flaps with the power of the flow.

Wilo also provides dual pump stations using this system. In these units, the pumps can be used alternately and a separate solids separation reservoir is assigned to each pump.

This kind of solids separation enables the use of high efficiency pumps with a small ball valve passage – less than 80 mm – which are powered by motors with comparatively low output and low power consumption – making them energy efficient, Wilo says, who claims that operating costs can be lower than for a conventional installation without a solids separation system.

www.wilo.com

WIlo’s solids separation system for sewage pumps.

Conductivity sensors improve accuracyInvensys Process Systems has introduced a compact, non-invasive conductivity sensor for high purity measurement in low volume liquid applications. The Foxboro FT10 Electrodeless Conductivity sensor features patent-pending technology for highly accurate conductivity sensing; and a flow-through design for reduced operational and maintenance costs.

The Foxboro FT10 flow-through design allows the process fluid to pass through an opening in the sensor, thus eliminating the need to insert probes into the process line. As the fluid passes through the sensor, conductivity is measured with Foxboro’s multi-toroid technology. The primary toroid induces electric current in the process fluid.

The voltage created is detected by secondary toroids and is converted to a conductivity measurement. The multi-toriod design allows the FT10 to accurately measure the full scale of conductivity, ranging from 0 to 2000 mS/cm.

The FT10 can be installed as an integral part of the process piping, or surface mounted, and is suitable for applications in the semiconductor, specialty chemical, electronic and LED industries, and selected pharmaceutical applications.

These include measurement of high-purity, and/or concentrations of aggressive chemicals such as hydrofluoric, hydrochloric, nitric, and sulphuric acids, ammonium hydroxide, and tetra-methyl ammonium hydroxide.

www.invensys.com

Invensys’conductivitysensors for high purity measurement.

Arsenic removal receives drinking water certificationThe Water Quality Association has certified Purolite’s ArsenXnp product under the NSF/ANSI-61 Standard for Drinking Water for multiple regenerations, making it the first arsenic removal product of its kind to receive this certification, Purolite says.

ArsenXnp can now be regenerated multiple times, providing operating cost reductions for arsenic removal in drinking water. It can also be retrofitted into existing plants that use one-time arsenic removal media such as GFO, GFH or TiO2.

“We have been developing this innovation for the last 12-14 months realizing that the environmental impact and cost of removing arsenic from drinking water were significant hurdles to overcome,” said Jacob Brodie, Purolite vice president.

www.purolite.com

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