Rotating Drum Screens – Self-Cleaning Solid-Liquid Separation Technology

Headquartered in Delta, British Columbia, within the Greater Vancouver area, Pureworld Solutions Inc. supports industrial and municipal clients throughout Western Canada with Johnson Screens Contra-Shear® rotating drum screens and advanced screening technologies for efficient solid-liquid separation applications.

Pureworld Solutions Inc. — Expertise in Rotating drum screens

At Pureworld Solutions Inc., we specialize in the application engineering, sizing, supply, and long-term support of Johnson Screens® Contra-Shear® rotating drum screens. Johnson Screens, a brand of Aqseptence Group, is a global leader in screening and separation technology with over 50 years of proven performance.

The Contra-Shear® Next Generation rotary fine screen offers improved features and innovations that assist every user in realizing their journey towards environmental sustainability. These screens increase solids dewatering and capture rate, expand the range of viable applications, and increase the visibility of the screening process.

Contra-Shear® Next Generation Rotating Drum Screens

The Contra-Shear® Next Generation from Johnson Screens is a self-cleaning, internally fed rotary fine screen that relies on the shear force effect created by rotation of the drum to enhance the separation of solids from effluent.

Key Features:• Direct drive design – no chain or lubrication required (lube-free operation)• In situ trunnion replacement eliminates the need for drum removal or lifting• Clear view inspection hatches as standard for process visibility• Maintenance-free sealed-for-life stainless steel bearings• Expanded range of sizes available• Available in 304 and 316 stainless steel construction• Angled frame rail prevents settling of solids/liquids inside the machine• Vee-Wire® screen elements for superior performance

How Contra-Shear® Rotating Drum Screens Work

The Contra-Shear® rotating drum screen operates as follows:

1. Slurry or effluent is fed internally into the rotating drum2. Screened effluent passes through the Vee-Wire® slots into a tank for further processing3. The shear force effect created by drum rotation enhances solid-liquid separation4. Solids in the dewatering zone amalgamate and are continuously rolled due to drum rotation5. Rolling action results in further reduction of liquid content in the solids6. Dewatered solids are discharged for disposal or further processing7. Clean water is pumped from the collection tank for discharge or reuse

The Contra-Shear® Next Generation design significantly simplifies maintenance with an external rack and pinion drive mounted on the clean side of the screen, keeping impurities away from drive elements while providing excellent accessibility during maintenance.

Key Advantages

• Maximizes dewatering capabilities thanks to exclusive Contra-Shear technology
• Enhances hygiene in processes by reducing contamination risk with innovative lube-free design
• Reduces downtime and need for labor and consumables with easy-to-maintain design
• Streamlines equipment needs with engineered weir design allowing smaller or fewer machines
• Direct drive eliminates chains, sprockets, oilers, and virtually all other wearing parts
• No lubrication required – ideal for food and sanitary applications
• Clear view inspection hatches allow monitoring of screening process
• Stainless steel construction provides durability and corrosion resistance
• In situ trunnion replacement reduces maintenance time and complexity
• Compact footprint compared to alternative screening technologies

Industries Served

1. Food & Beverage Processing – Waste screening, product recovery, wash water treatment
2. Pulp & Paper Mills – Fiber recovery, effluent screening, white water treatment
3. Municipal Wastewater Treatment – Primary and secondary screening, biosolids processing
4. Industrial Water Treatment – Process water clarification, effluent polishing
5. Sugar Processing – Juice screening, mud separation, process water treatment
6. Water Intake Facilities – Raw water screening, debris removal
7. Breweries & Wineries – Spent grain separation, lees processing, wash water
8. Dairy Processing – Whey processing, wash water treatment
9. Meat & Poultry Processing – Effluent screening, rendering waste processing
10. Pharmaceutical & Chemical – Process screening, waste treatment

Common Applications

• Primary screening of municipal wastewater influent
• Fiber recovery in pulp and paper operations
• Food processing waste screening and dewatering
• Industrial effluent treatment and solids removal
• Sugar mill mud screening and juice clarification
• Brewery spent grain separation and dewatering
• Dairy whey processing and solids recovery
• Meat processing effluent screening
• Water reuse and recycling systems
• Any process requiring precise dewatering and solid-liquid separation

Frequently Asked Questions

What makes Contra-Shear® rotating drum screens different from other drum screens?

Contra-Shear® technology uses the shear force effect created by drum rotation to enhance solid-liquid separation. The Next Generation design features a direct drive with no chains or lubrication required, in situ trunnion replacement, and clear view inspection hatches. This results in superior dewatering performance with significantly reduced maintenance requirements.

What screen opening sizes are available?

Johnson Screens Contra-Shear® rotating drum screens utilize Vee-Wire® screen elements available in various slot widths to suit specific application requirements. Pureworld Solutions Inc. assists with selecting the appropriate screen opening based on particle characteristics and downstream processing requirements.

What materials of construction are available?

Contra-Shear® rotating drum screens are available in 304 and 316 stainless steel construction. Material selection depends on the application, fluid characteristics, and corrosion requirements. The sealed-for-life stainless steel bearings provide maintenance-free operation.

How does the lube-free design benefit food processing applications?

The Contra-Shear® Next Generation eliminates chains, sprockets, oilers, and lubrication requirements. The direct drive mounted on the clean side of the screen keeps impurities away from drive elements. This hygienic design reduces contamination risk, making it ideal for food and beverage, dairy, and other sanitary applications.

Why choose Pureworld Solutions Inc. for rotating drum screens?

Pureworld Solutions Inc. provides local Western Canadian expertise, application engineering, commissioning assistance, and long-term technical support for Johnson Screens Contra-Shear® rotating drum screens. We ensure proper equipment selection and configuration for your specific solid-liquid separation requirements.