Deep Dive: ErtelAlsop Pak® Lenticular Filters

Introduction to ErtelAlsop Pak® Lenticular Filters

In the world of industrial liquid filtration, efficiency and containment are paramount. For decades, the standard was the plate and frame filter press—effective, but often open to the environment and labor-intensive to change. Enter the ErtelAlsop Pak® Lenticular Filter (also known as the Pak® Cartridge).

Originally innovated by Alsop Engineering (now ErtelAlsop) in the 1940s, the lenticular format enables the superior depth filtration technology of a filter press to be utilized in a totally enclosed, sanitary, and easy-to-handle cartridge. At Purecowater, we provide these high-performance modules to solve complex solid/liquid separation challenges across pharmaceutical, food & beverage, and industrial chemical sectors.

What is a Lenticular Filter Module?

A Pak® Cartridge is essentially a pre-assembled stack of depth filter sheets. Instead of manually placing sheets between plates, the media is cut into discs and sealed around a central polypropylene core.

The term “lenticular” refers to the shape—resembling a stack of double convex lenses. This design maximizes surface area within a compact footprint. Fluid flows from the outside of the cartridge, through the media, and into the center core, effectively trapping particulates within the tortuous path of the depth media.

Key Advantages

• Enclosed System: Eliminates leakage and exposure to the atmosphere, protecting both the product and the operator.
• Scalability: Available in 12-inch and 16-inch diameters with varying cell counts (surface areas), allowing easy scale-up from pilot to production.
• Rapid Change-out: Modules can be swapped in minutes compared to the hours often required for plate and frame presses.
• High Solids Loading: The depth media structure allows for significant contaminant retention before blinding.

Product Configurations and Media Types

ErtelAlsop offers a comprehensive range of media formulations to target specific contaminants. Whether you need to remove sub-micron bacteria or clarify a viscous oil, there is a Pak® configuration available.

Product Series	Primary Media Composition	Ideal Application
Zeta-Pak®	Cellulose + DE/Perlite + Resin	The “Workhorse.” General clarification, pharmaceutical polishing, and haze removal. High positive zeta potential.
Disc-Pak®	100% AlphaMedia Cellulose (No DE)	Dielectric oils, perfumes, and applications requiring no inorganic migration.
AquaKv-Pak®	Specialized Absorptive Media	Electric utility industry. Removes water and carbon from transformer insulating oils.
MicroClear® Pak	Immobilized Activated Carbon	Color correction, odor removal, and decolorization without loose carbon dust.

Technical Specifications

When selecting a lenticular module, compatibility with your existing housing and process parameters is critical. ErtelAlsop Pak® cartridges are designed to fit most industry-standard lenticular housings.

• Micron Ratings: Nominal retention ranging from 0.25 to 15 microns.
• Diameters: 12 inch (30.5 cm) and 16 inch (40.6 cm).
• Core Material: Heavy-duty Polypropylene (standard).
• Gasket Materials: EPDM, Viton, Silicone, Buna-N, and Teflon Encapsulated.
• End Cap Styles: Flat Gasket or Double O-Ring (typically 222 or 226 styles).
• Cell Counts: Stacks typically range from 5 to 16 cells high, depending on surface area requirements.

Industries Served

The versatility of the Pak® design makes it a staple in various high-purity sectors:

• Pharmaceuticals & Biotechnology: Clarification of cell cultures, removal of endotoxins using Zeta-Pak®, and lipid removal in botanical extracts.
• Food & Beverage: Haze removal in distilled spirits, syrups, and wines. The enclosed design ensures no flavor contamination.
• Utility & Power Generation: The AquaKv-Pak® is the industry standard for restoring dielectric strength in transformer oils by removing moisture and particulates.
• Chemicals & Solvents: The Disc-Pak® offers excellent chemical compatibility for filtering solvents where Diatomaceous Earth (DE) is not permitted.

Why Choose Purecowater for Deployment?

Purecowater acts as a specialized distributor and OEM partner, helping you integrate ErtelAlsop solutions into your existing workflow. Whether you require a single housing retrofit or a complete skid system, our expertise ensures you select the correct media grade and micron rating for your specific fluid stream.