Primary Filter, Raw River Water, Cement Factory – De Hoek

GraviFilter Self Cleaning Gravity Screen Filter

Client: PPC Ltd
Industry: Mineral Processing – Cement Production
Region: Western Cape, South Africa
Product: VA4, 100m³/h, 250µm
Installation Date: 2014


  • PPC Ltd uses raw river water for plant process water as well as for potable water.
  • Suspended solids in the raw water cause damage to high-pressure pumps. The solids also block spray nozzles on the plant and it is an unacceptable component of the potable water.
  • The suspended solids in the raw water consist of organic detritus (decomposing leaves, bark fibers), pebbles, grit and sand.
  • These types of solids present problems to in-line pressure filters and the solids are best removed by gravity filters (not pressure filters).
  • The long distance between the extraction point and the plant makes it necessary that the filter must operate unattended for long periods of time and be self-cleaning.


  • Final Filtration / Protection of the high-pressure pump.
  • Final Filtration / Protection of spray nozzles on the plant.
  • Pre-Filtration / Removal of suspended solids from the feed to the potable water treatment plant.


  • The gentle, unforced filtration action of the GraviFilter is ideally suited to remove soft, organic and fibrous suspended solids from process streams.
  • Raw water gravitates through the screen, avoiding the vulnerability of permanent blockage or damage to the screen.
  • The unforced filtration process prevents the breaking up of flocculated particles and organic matter.
  • Stapling of fibrous suspended solids is greatly reduced.
  • The integral, self-cleaning mechanism ensures long filtration runs without the need for manual cleaning of the screens.
  • The client installed a GraviFilter model VA4 with integral, self-cleaning mechanism. 100m³/h. 250µm screens.


  • Reduction in maintenance costs and downtime on the high-pressure pump.
  • Reduction in costs associated with blocked nozzles on the plant.
  • Improvement in the quality of water presented to the potable water treatment plant.


“We are very satisfied with the results of installing this GraviFilter. There has been a significant reduction in the maintenance costs on the high-pressure pump. The filter is self-cleaning with very low maintenance. It is durable and operates unattended for extended periods.”