Introduction to ErtelAlsop Pak® Lenticular Filters
In the world of industrial liquid filtration, consistency, efficiency, and ease of use are paramount. ErtelAlsop Pak® Lenticular Filters represent a significant evolution in depth filtration technology. Originally invented by Alsop Engineering (the predecessor to ErtelAlsop) in the 1940s, the lenticular cartridge format offers a totally enclosed, leak-free alternative to traditional plate and frame filter presses.
At Purecowater, we understand that selecting the right filtration method is critical for product quality. Whether you are dealing with pharmaceutical fluids, distilled spirits, or industrial chemicals, the Pak® Lenticular series provides a versatile solution designed to handle high solid loads while maintaining strict retention standards.
This guide explores the specifications, benefits, and applications of ErtelAlsop Lenticular Filters, helping you determine if they are the right fit for your process.
What is a Lenticular Filter?
A lenticular filter module (often called a “Pak” or “cartridge”) consists of individual filtration cells stacked vertically. Each cell is constructed from two circles of depth filter media sealed at the outer edge. The resulting shape resembles a double convex lens, which gives the technology its name.
These modules are housed in a sealed vessel, allowing liquid to flow from the outside of the typically 12-inch or 16-inch diameter stack, through the media, and into a central core. This design combines the high surface area and dirt-holding capacity of depth filtration sheets with the convenience of a cartridge system.
Key Features and Benefits
1. Superior Depth Filtration
The core power of the Pak® cartridge lies in its media. These filters do not just screen particles on the surface; they trap contaminants throughout the thickness of the media matrix. This “tortuous path” filtration allows for:
- High Solids Loading: Capable of holding significant amounts of precipitate and mist without rapid clogging.
- Zeta Potential: Many ErtelAlsop media options retain particles smaller than the mechanical pore size through electrokinetic adsorption.
- Water Removal: Specific media grades can adsorb trace water from oils.
2. Operational Efficiency
Unlike plate and frame presses, which can be labor-intensive to clean and prone to leakage, lenticular housings are user-friendly. A typical change-out can be performed in minutes rather than hours, minimizing downtime. The totally enclosed system also prevents fluid loss and protects operators from exposure to process fluids.
3. Versatile Configurations
Pak® cartridges are designed to fit a wide range of housings and applications. They generally feature:
- Diameters: 12-inch (30.5 cm) and 16-inch (40.6 cm).
- Stack Heights: Variable cell counts (typically 5 to 18 cells) to adjust surface area.
- End Caps: Flat Gasket (standard) or Double O-Ring (usually for sanitary/pharma applications).
Product Series Overview
ErtelAlsop manufactures several series within the Pak® family to target specific industry needs.
| Series | Media Composition | Ideal Application |
|---|---|---|
| Zeta-Pak® | Micro-Media® (Cellulose, Fiber, DE/Perlite) | General purpose, pharma, food & beverage. High zeta potential for fine particle removal. |
| Disc-Pak® | AlphaMedia™ (100% Cellulose) | Ideal for dielectric oils, perfumes, and applications where no DE (Diatomaceous Earth) is required. |
| Bio-Pak® | Premium Depth Media | Pharmaceutical grade. Features a double O-ring connection and rigid polymeric core for maximum sanitary integrity. |
| MicroClear® | Activated Carbon Impregnated | Color, odor, and flavor correction without loose carbon powder mess. |
Sources: ertelalsop.com (Cartridges), clearsolutionscorp.com (Disc-Pak)
Technical Specifications
When selecting a lenticular filter, matching the specifications to your process flow rate and viscosity is essential. Below are the general specifications for the ErtelAlsop Pak® line.
| Micron Ratings | 0.25 µm to 15 µm (Nominal) |
| Module Diameters | 12″ and 16″ |
| Max Operating Temperature | Typically up to 180°F (82°C) depending on gasket material |
| Core Material | Polypropylene (Standard) |
| Gasket Materials | EPDM, Buna-N, Silicone, Viton, Teflon Encapsulated |
| Sterilization | Can be steam sterilized in-situ (SIP) or hot water sanitized. |
Common Applications
The flexibility of the Pak® system allows it to be used across diverse sectors.
Pharmaceutical & Biotechnology
Fulfilling rigorous sanitary requirements, the Bio-Pak® and pharma-grade Zeta-Pak® are used for cell harvesting, clarification of fermentation broths, and protection of downstream membrane filters. The enclosed design ensures sterility is maintained.
Food & Beverage
From distilled spirits to syrups, lenticular filters are standard for haze removal and polishing.
Notable Use: Botanical Extracts. The high surface area allows for high flow rates while media containing diatomaceous earth efficiently strips waxes and lipids from extracts.
Industrial & Chemical
Disc-Pak® filters (cellulose only) are heavily utilized in processing lubricating oils, dielectric oils, and coolants where adding mineral components (like DE) must be avoided.
Cosmetics
Ensuring the clarity and purity of perfumes, lotions, and essential oils.
Conclusion
ErtelAlsop Pak® Lenticular Filters offer a proven, scalable, and sanitary solution for depth filtration needs. By moving away from open presses to enclosed lenticular modules, facilities can improve worker safety, reduce product loss, and achieve consistent high-quality filtrate.
Purecowater is equipped to help you identify the specific media grade and housing configuration required for your unique application.
Need help sizing a lenticular filtration system for your process?