Return Water Filtration

Closed-loop cooling systems accumulate suspended solids from corrosion products, biological growth, makeup water, and airborne contamination. Solids deposit on heat exchangers reducing efficiency. Multimedia filtration removes particulates maintaining clean operation.

Filter Design

Vertical pressure vessel with cooling water return inlet distributor, anthracite layer 18-24 inches removing larger particles, sand layer 12-18 inches capturing finer solids, garnet layer 6-12 inches final polishing, gravel support bed, underdrain system.

Media Specifications

Anthracite effective size 1.0-2.0mm, sand 0.5-0.8mm, garnet 0.3-0.5mm. Graded density prevents intermixing during backwash. Total bed depth 36-54 inches. Media life 5-10 years with proper operation and backwash.

Operating Pressure

Typical 50-150 psig matching cooling system pressure. Clean bed pressure drop 5-10 psi increasing to 15-20 psi at end of run signaling backwash requirement.

Filtration Performance

Removes suspended solids to 10-20 microns. Turbidity reduction from 10-50 NTU to under 5 NTU. Efficiency depends on loading rate typically 5-10 gpm per square foot bed area.

Material Construction

Carbon steel with epoxy coating or stainless steel for cooling water service. Materials resist corrosion from treatment chemicals. Internal distribution and underdrain corrosion-resistant. External coating for atmospheric protection.

Backwash System

Upflow water at 15-20 gpm per square foot expands bed 30-50% washing trapped solids to drain. Air scour optional for heavily loaded applications. Backwash frequency based on pressure drop typically every 24-72 hours.

Applications

Industrial closed-loop cooling systems, HVAC chilled water circuits, process cooling water loops, power plant auxiliary cooling, data center cooling systems, and any recirculating cooling requiring solids removal.

Heat Exchanger Protection

Clean water prevents fouling deposits maintaining thermal efficiency. Suspended solids create insulating layers reducing heat transfer 10-30%. Filtration preserves design performance reducing energy consumption.

Side-Stream Filtration

Common configuration treats portion of cooling water flow continuously. Typical side-stream 3-10% of total circulation. Complete water turnover every 10-30 hours depending on contamination rate.

Full-Flow Option

Smaller cooling systems filter entire flow continuously. Requires larger filter and pumping capacity but achieves faster cleanup. Selection based on system size and water quality requirements.

Corrosion Product Removal

Filtration captures iron oxide, copper oxides, and other corrosion products preventing deposition. Removes biological material from biocide treatment. Maintains clean system reducing maintenance and chemical costs.

Capacity Sizing

Filter area based on flow rate and loading rate. Multiple filters provide redundancy during backwash cycles. Proper sizing ensures continuous cooling system operation.

Performance Benefits

Maintains heat transfer efficiency through solids removal. Protects equipment from fouling and under-deposit corrosion. Reduces chemical treatment consumption. Simple proven multi-media technology.

Construction Standards

Pressure vessels per ASME Section VIII. Materials for cooling water with treatment chemicals. Backwash system design per hydraulic calculations. Complete documentation with filtration specifications and media gradation.

ERGIL cooling water return multimedia filters provide suspended solids removal maintaining clean efficient closed-loop cooling systems in industrial and commercial applications.