CASE STUDY: EDUCTOR APPLICATION
Filter Bed Media Transfer with ELMRIDGE Liqui-Jet Solids Eductor
ELMRIDGE recently had a customer call with a project that involves moving large volumes of filter media (sand/gravel), in a municipal water treatment plant. This customer has previously used a tracked front end loader and dump trucks to remove (and ultimately replace), huge volumes of sand and gravel from filter bed galleries in a process that has taken weeks or months to complete using significant manpower. After discussion with our technical staff, it was determined that plentiful Motive water is available (it is a water treatment plant after all), at a pressure suitable to power an eductor or eductors whereby the sand/gravel slurry can be sucked directly out of the filter beds and pumped into the back of a dump truck. This is a fairly common application for a Liqui-Jet solids eductor and typically requires the following basic materials:
1. Flexible Motive water supply hose (sized to provide the eductor with the required design flowrate and pressure)
2. Flexible Suction hose (rated for the required duty but light enough to move around)
3. Lightweight Suction Wand – with handle(s)? (connected to the Suction hose to allow manipulation)
4. ELMRIDGE Liqui-Jet Solids Eductor (suitably sized)
5. Flexible Discharge hose (suitably sized and rated for the required duty but light enough to move around)
6. Miscellaneous valves / pipe & hose fittings / clamps etc. – as required
Depending on the distance that the sand/gravel slurry must be lifted and pumped, a suitably sized Liqui-Jet solids eductor may located on an adjacent mezzanine whereby a flexible Suction hose (and perhaps a Suction wand), is lowered into the filter gallery and manipulated by personnel as required. The solids eductor could also be lowered into the gallery whereby the Discharge head capability of the eductor is relied upon more heavily. Typical operating conditions for a 3″ pipe size solids eductor may be as follows:
Motive Water: Approx 210 usgpm of 70° water (SG = 1.0) @ 100 psig
Suction Slurry: Approx 100 usgpm of 70°F sand/gravel slurry (combined SG = 1.5) @ 10 feet lift
Discharge: Combined flow @ up to approx 25 psig
A single solids eductor with the operating characteristics outlined above has the ability to move approximately 30,000 cubic feet of saturated sand/gravel slurry in less than a single [8 hour per day] work week.
ELMRIDGE supplied an all 316L stainless steel eductor from stock with NPT threaded connections and removable/replaceable nozzle and diffuser components. Our customer was amazed at how productive a solids eductor could be in this application and has additional similar jobs lined up for use with the same equipment.