Doxie® Hydrocyclones

Mechanical Seal and Bearing Protection

Doxie Cyclone Impurity Eliminators protect mechanical seals or bearings from abrasive dirt.

Doxie Hydrocyclones

Put an end to the constant maintenance problems and expenses caused by damaged mechanical seals or canned pump bearings. Now you can quickly and inexpensively elimiate costly repairs and equipment downtime due to damaged mechanical seal or canned pump bearing problems with a Doxie Impurity Eliminator.
The Doxie cyclone is a separator with no moving parts. There is nothing to adjust and no maintenance problems. In operation, the Doxie uses centrifugal force to spin abrasive particles from the liquid which flows onto the bearings or the dynamic seals on rotating shafts. Solids as small as a few microns in diameter are separated and removed. Only cleaned fluid reaches the rubbing surfaces of expensive equipment. The abrasive particles are literally spun from the flow by centrifugal force.
The Doxie Hydrocyclones are a relatively low cost answer to removing impurities from feed streams. As long as there is enough pressure differential to operate a cyclone, installation is simple.
There are three Doxie cyclone modules available to choose from to meet specific needs, pressures and operating temperatures. The Doxie 5 unit consists of six 10-mm cyclones in parallel operation and is machined from a solid block of 316 stainless steel. The Doxie Type A unit is a single 10-mm cyclone constructed in a similar manner. Both handle pressures up to 2,000 psi at temperatures from ambient up to 100°F.
The Doxie Type P unit is designed to operate efficiently with pressures up to 600 psi at ambient temperature and up to 200 psi at temperatures up to 200°F. It is available in Nylonor or Kynar® construction.

Separation Efficiency

Differential pressure is critical for proper operation. The higher the differential pressure, the more efficient the separation action. The differential pressure is the drop from the feed pressure to that of the overflow. Cyclone separators, such as the Doxie units, should not be used in applications where the pressure differential is less than 20 psi. Cyclone design plays a big part in developing high separation efficiency. The shape of the cyclone, the angle of its cone, the underflow opening size; all are important. The technological exprience and leadership of FLSmidth engineers in hydro-cyclonic separation assures you the finest design and the highest operating efficiency.

How The Doxie Cyclone Operates

Feed from the pump discharge is piped into the inlet which enters tangential to the cyclone cone. The liquid therefore rotates at a high velocity, very much like a whirlpool.
Sand, dirt and other very fine particles are thrown to the wall of the Doxie cyclone and pass downward and out the underflow discharge.
Cleaned liquid spins into the center of the cyclone and is forced upward and out the overflow discharge. This clean stream is then routed through tubing to the place of usage - the mating surfaces of the shaft seal or to the bearings.
The pump provides all the pressure drop energy that is needed to provide the separation.

Which Doxie Cyclone?

  1. Designate flow required. This may be the flow required for a mechanical seal. Since the Doxie cyclone splits the flow 60% clean to the overflow and 40% dirty to the underflow, divide the required flow (GPM) by .60 and this will give the feed flow required. The overflow flushes and cools the mechanical seal.
  2. Establish the size of the particles to be removed. The Doxie cyclones, Types A and 5 (10-mm diameter), are used to remove partilcles in the range of 3-8 microns in diameter. The Type P cyclone (25-mm diameter), is used to remove particles in the range of 10-15 microns. These size ranges are based on solids having a 2.7 specific gravity suspended in water.
  3. Use charts below this information or located in the linked PDF file at the bottom.

Doxie Hydrocyclone  graph

Represented in Canada by:
ICR Water Technologies Inc.
3-200 Memorial Avenue, Suite 101
Orillia, Ontario
L3V 5X6
Phone or Fax to: (888) 281-7774

For more information on this product and to view the in-depth statistics please click here to read the full PDF brochure.