The Dow Chemical Company

DOW UltrafiltrationOperation and Design Guidelines

DOW UFOperation Modes

DOW UF Operation Philosophy

Filtration(20-60 min)

Air Scrub (20s)Backwash (40-60s)

Forward Flush (30-60s)(Physical Cleaning)

CEB (On-Line); Every 1-7 daysCIP (Off-Line); Every 1-12 months

(ChemicalCleaning)

DOW UF Operation Philosophy

ChemicalEnhancedBackwash

CIP

BW Trend

CEB Trend

Filtration (Dead-End Mode)

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

Filtration (Bleed Mode)

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

Air Scour

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

Gravity Drain

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

Backwash Top

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

NaOCl(optional)

Backwash Bottom

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

NaOCl(optional)

Forward Flush / Rinse

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

CEB Top

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

Chemicals

CEB Bottom

Ultrafiltrate

Raw Water

Filter100-300 m Air

BackwashPump

Feed Pump

Waste

BackwashTank

Chemicals

CIP Filtrate Side

Solution(up to 40C)

CIP Pump

Feed Side

DOW UFDesign Guidelines

DOW UF Design Guidelines