Filtration is a critical component in industries ranging from pharmaceuticals to food and beverage processing. When dealing with fluids containing high solid loads or requiring specific retention efficiencies, standard cartridge filters often fall short. This is where ErtelAlsop Pak® Lenticular Filters excel.
As a distributor for premium filtration solutions, Purecowater is proud to offer ErtelAlsop’s line of depth filter cartridges. This article provides a comprehensive technical overview of these lenticular filters, their operating principles, available configurations, and ideal applications.
What is an ErtelAlsop Pak® Lenticular Filter?
The ErtelAlsop Pak® is a depth filter cartridge (often called a lenticular module) designed for high-efficiency particle retention and high solids loading capacity. Unlike surface filters that trap particles only on the outer layer, depth filters utilize a complex matrix of fibers and filter aids to trap contaminants throughout the entire thickness of the media.
These cartridges consist of multiple lenticular cells—lens-shaped distinct filter discs—stacked vertically. Each cell is comprised of two sheets of depth filter media (such as MicroMedia®, AlphaMedia®, or MicroClear®) sealed at the edges. This “stacked disc” design significantly increases the surface area within a compact footprint, allowing for higher flow rates and greater dirt-holding capacity compared to traditional pleated cartridges.
How It Works
Fluid enters the filter housing and surrounds the lenticular cartridge. The flow path is outside-in:
- Entry: Liquid passes from the housing vessel through the outer surface of the media sheets.
- Filtration: As fluid traverses the tortuous path of the depth media, particles are trapped via mechanical interception and electrokinetic adsorption (Zeta Potential).
- Exit: The filtered clean liquid creates a pressure differential, flowing into the center core of the module and exiting through the outlet.
Product Configurations and Series
ErtelAlsop offers several formulations to meet specific chemical compatibility and filtration goals. Below is a breakdown of the primary series available.
| Series Name | Primary Application | Key Features |
|---|---|---|
| Zeta-Pak® | General Purpose, Pharma, Indutsrial | The “workhorse” of the line. High zeta potential, excellent for ultra-fine particle retention. Contains cellulose, filter aid, and resin. |
| ZetaDri-Pak® | Water Removal from Oils | Designed to absorb free and emulsified water from oils (transformer, silicone, food oils). Holds up to 148 oz of water per cartridge. |
| Bio-Pak® | Critical Pharmaceutical/Biotech | Features a Double O-Ring seal to ensure zero bypass. Pharmaceutical grade media with validation guides available. |
| Disc-Pak® | Sensitive Liquids (Extractables) | 100% cellulose (AlphaMedia™) or specialized grades. No resins or binders, utilized where low extractables are required. |
| AquaKv-Pak® | Dielectric Fluid Reconditioning | Optimized for transformer oils. Combines particulate retention with water absorption capability (up to 120 oz/pak). |
Technical Specifications
When selecting a Pak® cartridge, compatibility with existing housings and process conditions is vital. ErtelAlsop cartridges are manufactured with over 300 precision dies to fit virtually any filter press or housing configuration.
Dimensions and Construction
- Diameters Available: 12 inch (30.5 cm) and 16 inch (40.6 cm)
- Stack Height: Standard options include 7½” or 10⅞” (depending on cell count)
- Number of Cells: Typically 5 to 18 cells per module
- Micron Ratings: Nominal retention from 0.25 to 15 microns
Material Options
| Filter Media | Cellulose, Diatomaceous Earth (DE), Perlite, Activated Carbon, Polypropylene |
| Core Material | Polypropylene or Stainless Steel Straps |
| Gasket Materials | Viton, Buna-N, Neoprene, EPDM, Silicone, Teflon Encapsulated |
| End Cap Styles | Flat Gasket or Double O-Ring |
Double O-Ring Detail
Flat Gasket Detail
Why Choose ErtelAlsop Lenticular Filters?
1. Superior Solids Loading
The matrix structure of the media allows for the capture of negatively charged particles smaller than the mechanical pore size (Zeta Potential). This results in a higher solids loading capability compared to surface filters, reducing change-out frequency.
2. Leak-Free Design
The Bio-Pak® and other high-grade options offer Double O-Ring seals. This design ensures a positive seal within the housing, eliminating fluid bypass—a critical requirement for pharmaceutical and sterile applications.
3. Versatile Media Options
Whether you need activated carbon for color/odor removal (MicroClear®), pure cellulose for low extractables (AlphaMedia®), or high-performance DE media (MicroMedia®), there is a formulation for every fluid type.
4. Ease of Handling
Lenticular modules are essentially pre-assembled stacks of filter sheets. This format makes them significantly easier to load and unload compared to traditional plate and frame filter presses, reducing labor costs and downtime.
Industries and Applications
The versatility of the Pak® cartridge makes it a staple in numerous sectors:
- Pharmaceuticals: Clarification of culture media, blood plasma fractionation, and removal of endotoxins using L-Series media.
- Food & Beverage: Polishing of syrups, distilled spirits, and haze removal in fruit juices.
- Utility & Power: Removal of water and carbon from transformer oils (ZetaDri-Pak®).
- Chemical Processing: Filtration of bulk chemicals, silicone oils, and resins.
- Cosmetics: Clarification of perfumes, lotions, and essential oils.
Get a Quote for ErtelAlsop Filters
Purecowater is your trusted partner for diagnosing filtration challenges and supplying the highest quality engineered solutions. Whether you are upgrading an existing system or sizing a new process, our team can help you select the correct Pak® configuration.