Process Description 

Media filtration is very effective in reducing turbidity, foul tastes, and odors by removing impurities through chemical absorption and physical straining of the water between the media material. The example above illustrates a media filtration process utilizing a sand filter. In this, process water flows through a sand filter which is filled with select types of media material (depending on the application). The sand filter removes select impurities and/or flocculation from the treated water. Many industrial applications can have as many as four sand filters, depending on process requirements. Common issues in media filtration include:

• Impurities such as: Silt, Clay, Flocculants, Colloids (bacteria, plankton), Iron, Magnesium, Chlorine
• Types of media: Activated Carbon, Sand, Garnet (glassy sand material), Gravel, Earth
• Gravity feed : Water pressure or water level above the media forces the water through the filter media.
• Pressure Filtration: Media is enclosed in a vessel. The water is introduced into the vessel under pressure.

Measurements in Media Filtration

Flow:

1. Monitors the influent water stream and tracks the amount of total water processed through the media. This is a good indicator for planning maintenance on the system.
2. Monitors the use of the product water being used in the application.

Pressure: Measure the pressure drop across the membrane. An increased pressure differential across the membrane indicates a need for backwashing of the filter.

• High quality, low cost
  paddlewheel for reliable
  measurement

• Wide flow range of for
  measuring varying flow
  rates

• Choice of wetted materials
  for compatibility to process
  environment

• Insertion style magmeter
  for easy installation in up to
  8 in. pipes

• Reliable measurement
  even in dirty liquids

• 4 to 20mA output available
  for direct input to PLCs or
  chart recorders

• Digital (S³L) output for long
  cable runs without
  compromising signal output

• ¾ inch process connection
  for easy installation

• 4 to 20 mA output available
  for wiring directly to PLCs or
  chart recorders

• Level measurement via
  pressure sensor for accurate
  low cost measurement

• Digital (S³L) output for long
  cable runs without
  compromising signal output