Pile Cloth Media Filtration

In over 45 years of experience in the operation and development of PCMF technology, Mecana now has hundreds of reference plants throughout Europe and together with Aqua-Aerobic Systems, Inc. thousands worldwide. OptiFiber is the standard for Pile Cloth Media Filtration. All filter systems are manufactured in Switzerland according to Swiss quality standards.

«Pile cloth media filtration – filtration process that uses pile cloth media as the filter media and does not interrupt filtration during filter cleaning.

Pile cloth media filtration (PCMF) is a surface filtration process which, in addition to the sieve effect, also has filtration effects over the depth of the pile layer. Pile Cloth Media Filtration is a sub-area of cloth media filtration (CMF) and was developed and introduced at Mecana at the end of the 1990s. In PCMF, three-dimensional cloths (3D‑Filtration), known as pile cloth media, are used as filter media. The development of Mecana Cloth Filtration (MCF) began at the end of the sixties with the use of needle felts. The needle felts – non-woven cloth made of needled fibers, consisting of a large number of small fibers, with a backing fabric – were gradually replaced by woven pile cloth media. The difference between needle felts and pile cloth media lies in their flexible structure, so that the removal of retained substances during filter cleaning is much more effective with pile cloth media.

How Pile Cloth Media Filtration works

The liquid flows through the fully submerged pile cloth media mounted on the filter construction from the outside to the inside (outside-in filtration). The flat-lying pile fibers create a solid-separating pile layer during the filtration process. Removing solids increases hydraulic resistance, resulting in a rising water level or an increase of the differential pressure. At a certain level or pressure difference, filter cleaning is triggered. Retained solids are removed by fluidising (briefly raising) the pile layer during filter cleaning. In this process, the solids layer accumulated on the outside is removed from the pile cloth media in the reverse flow direction (inside-out filter cleaning). Filtration is not interrupted during cleaning. The interaction between the engineered pile cloth media (OptiFiber®), consisting of a filter-active fluidisable pile layer and a non-filter-active backing, and the filter cleaning system is decisive for the system. No additional water is required for filter cleaning. A backwash water storage tank is not required.

Pile Cloth Media Filters are designed as free-flow or closed-pressure systems. The poling material is either mounted on a disk, drum or rhombus (DiamondFilter), which results in the various designs. The design is based on the solids loading, solids surface loading, filter velocity and solids content specific to the pile cloth media and fluid.

Key Information

System-related advantages

24/7 continuous outside-in filtration
Automatic and load-dependent inside-out backwash
Resistant towards shock loads
Low backwash water amount, typically < 0.5 – 2% Feed
No aerosol and low noise pollution during filter cleaning
High filter performance without the use of chemicals

Low energy demand

Low total hydraulic loss (30 – 70 cm)
Low power consumption < 0.3 – 15 Wh/m³ (depending on load) only during filter cleaning and bottom sludge removal. Energy demand for disk filters between 0.3 Wh/m³ (filter cleaning every 2 hours) and 15 Wh/m³ (continuous cleaning)
Short cleaning cycles < 30 – 60 seconds/cleaning unit

Low space requirement

100% submerged OptiFiber® filter media
No external backwash water and backwash water tank
Advantage of filtration and sedimentation effects in the filter tank
Filter cleaning system inside the filter unit. External and dry-installed pump solution possible

Low maintenance and service costs

OptiFiber® pile cloth media can be cleaned quickly and easily (usually every 1 – 2 years) or replaced if necessary
Chemical cleaning of OptiFiber® possible, but usually not necessary

Applications

Tertiary filtration
Phosphorus removal
Micropollutant removal
Pile Cloth Media Filtration as Clarifier
Pre-Filtration UV- or Ozone-Desinfection
Primary Filtration and Post Primary Filtration
Combined Sewer Overflow
Road Runoff
Drinking water treatment
Surface Water Filtration
Water Reuse
Desalination
Membrane Pre-Treatment
Industry wastewater treatment

PCMF-Family

The pile cloth media is mounted either on a disk, drum or diamond, so that the fabric concept leads to the embodiments - disk, drum or diamond filter. Depending on the design form, there are system-related advantages.

Mecana
Disk Filter (MSF)

Mecana
Drum Filter (MTF)

Mecana
Pressure Drum Filter (MDF)

Mecana
AquaDiamond®

Mecana
Aqua MegaDisk®

OptiFiber® Pile Cloth Media

OptiFiber pile cloth media have been specially developed for water and wastewater filtration. The pile cloth media combines high removal efficiency, efficient backwash capability and long-term stability. OptiFiber are cloths with a multi-dimensional structure, consisting of a filter-active pile layer and a non-filter-active backing. The backing, made of continuous filaments with large flow-relevant pores, serves as a carrier for the pile layer. The pile layer is woven into the backing and consists of multiple filaments or fibers.

The OptiFiber pile cloth media is cleaned by the filter cleaning system, consisting of (pivoting) suction beam and (profiled) suction lip. During the cleaning process, the system automatically pulls itself towards the pile layer. The pile layer is fluidised by the backwash, resulting in an efficient removal of the solids embedded in filter media. The pivoting suction beam enables on-demand cleaning and prevents emissions from the filter surface that are not being cleaned. Filter cleaning is triggered automatically by time, water level or differential pressure. Filtration is not interrupted during cleaning.