Pressure Leaf Filter Basics

What is a Pressure Leaf Filter?

Pressure Leaf Filters are liquid filtration systems consisting of 10 to 60 leafs that are stacked inside a vertical or horizontal vessel. The leafs are drainage systems that support a wire or textile cloth cover. Since the filtration process is contained within a pressure-resistant vessel, it can be an ideal solution for hazardous processes.

Applications for Pressure Leaf Filter Solutions include Winemaking; Sugar Refining; Edible Oil Processing; Chemical Processing; Precious Metal Refining; Chlor-alkali; Soda ash; Liquid Sulfur Filtration; Oilfield Fluid Processing; Bauxite Refining.

Learn more below.

How do Pressure Leaf Filters Operate?

A filter cycle begins with the vessel sealing in the shaft and its filter leafs. Then, precoat is introduced. A precoat tank containing filtrate and filter aid (diatomaceous earth, perlite, etc.) is agitated for around 10 minutes. Then, the mix fills the vessel, vents all the air, and pressurizes. The precoat runs for 15 minutes at a fluid rate of ~ 30- 60 gallons per square foot per hour.

After precoating, the slurry is forced through the vessel under pressure. Solid particles are trapped in the precoat, or filter media while clarified liquid passes through and into a filter leaf. The liquids pass from leaf to the shaft’s interior, then out of the filter into a holding tank.

Between batches, liquid cake or sludge is drained from a valve. Dry cakes require a much larger opening; sometimes the entire vessel slides back for access to the leafs for discharge and cleaning.

What are the Two Types of Pressure Leaf Filters?

There are two types of leaf filter vessel configurations:  horizontal and vertical pressure filters.  Horizontal pressure filters are the most commonly operated due to their ease of operation and cleaning.  There are also more variations of horizontal pressure filters due to their operation and installation methods.  Vertical pressure filters are often used for small-flow, granular media filtration. Horizontal vessels are typical for larger flows because the horizontal layout increases the possible filtration area.  With vertical pressure filters, it is possible to have multiple vessels in one system, whereas with horizontal pressure filters, it is possible to have different cells in the same vessel.

Troubleshooting Pressure Leaf Filters

Torn or bent filter leafs can be the result of excessive body feed or running the filter too long between cleaning cycles. Did You Know…the Micronics Engineered Filtration Group can repair damaged leafs. The Micronics Engineered Filtration Group salvages good components and repairs or replaces only what is damaged. Typically a rebuilt leaf is around half the cost of a new one. We can repair or replace any OEM’s filter leafs!

Stop damaging your leafs by following these steps:

  • Keep differential pressure at 25 to 30 PSI between cleaning cycles. Do not depend on a set time cycle.
  • Cut back on the body feed.
  • Only precoat the frames until the filter aid is ¼” thick.
  • Check to see if your filter media has blinded.

New door gasket is leaking. If a replacement gasket was cut with straight ends, it may not create a perfect seal. Cut another with angled ends and install.

Pressure Leaf Filter Wear Parts

  • Replacement Shafts
  • Spray Headers
  • Roller Guides
  • Spray Nozzles
  • Bearings
  • V-Rings
  • V-Ring Adapters
  • O-Ring Seals
  • Leaf bags
  • Door Gaskets
  • Center Toggles
  • Front Toggles
  • Toggle Bearings
  • Chevron Seals
  • Custom Rubber Seals
  • Custom Teflon Seals
  • Filter Leafs

Micronics Repairs and Recovers Pressure Leafs From Every OEM

Do you have damaged pressure leafs? We can repair and replace all or part of the leaf in our trusted Salt Lake City, UT facility. Contact the Micronics Engineered Filtration Group and we’ll set up a free repair order for one of your leafs. You will only pay for the freight. We do this to demonstrate our craftsmanship and to provide a quote for repaired leafs, as well as new leaf replacements.

Want to save labor and shop space? Send us your leafs for bag recovery.

Contact Us today – Micronics will be pleased to come to your facility.

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Micronics Is Your Trusted Partner for Total Engineered Filtration Solutions. We offer end-to-end solutions from Filter Media to Industry-Leading Filtration Equipment, to Spare Parts & Accessories, to On-Site Field Services and In-House Laboratory Services. Whether for your Filter Press, Belt Press, Leaf Filter, Vacuum Filter, or Baghouse, you can count on Micronics’ deep industry and applications knowledge for the right engineered filtration solution to meet your needs. We look forward to working with your team.

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