Continuous Cast Coolant Filtration and

Caster Water Filtration

Presented By Tom Horn and Mohammed Al-Bedour

Filtertech, Inc. USA

Global Continuous Casting ForumAtlanta GA. April 2015

• Filtration system concepts• Coolant temperature management• Different filter types

Important Filtration Questions

• Flow rate? (for entire system sizing)• Pressure required? (for pump sizing)

• Heat to be removed? (heat exchange)• Available cooling water? (cooling tower)• Type of coolant to be used? • Single or split mill coolant systems?

System Sizing Factors

• Filter size in gpm/sq ft (roughing/finish)

• Tank volume (20 min. ideal 10 minimum)

• Pump size and type

Gravity Flow to the Filter

Heat Exchanger

Clean Supply PumpRecirculation Section

Clean Compartment

Recirculation Pump

Filter

Rod Mill

Gravity Flow Into Flatbed Air Vacuum Filter 20 MT/Hr SCR Mill With CLI Feature and Re-Circulated Filtration

Drain by Gravity to Self-Cleaning Conveyor Tank, Pump to Filter

Heat Exchanger

Filter Feed PumpClean Supply Pump

Filter

Rod Mill

Conveyorized Tank

1000 GPM (3800 LPM) System with Conveyor Tank & Flat Bed Vacuum Filters

Split System Concept for Roughing & Finishing Mills

Finishing Mill

Heat Exchanger Filter

Clean Supply Pump

Re-circulationFeed Pump

Reservoir Tank

Roughing Mill

Clean Supply Pump

Filter

Conveyorized Tank

Heat Exchanger

Filter Feed Pump

Flatbed Air Vacuum Filters For Roughing Mill 50 MT/Hr

Flatbed Air Vacuum Filter For Finish Stands 50 MT/HR

Coolant Filtration for Continuous Cast Aluminum Rod

• Concepts and Components (Same as copper)• Air Vacuum with Lower GPM/ft² (LPM/m²)

allows more filter area for the application• Higher Coolant Concentration• Higher Operating Temperature

Coolant Temperature Management

Coolant temperature management includes both system heat removal and heat addition to enhance coolant and rolling mill performance.

Process Heat Removal

Temperature Sensor

Controller105 F

To Process

Clean Supply Pump

Cooling Water

In

Out

Heat Exchanger

Plate and frame heat exchangers precisely remove the process heat from the coolant controlling the temperature with cooling water

System Tank

Electric Immersion

Heater

Temperature

Sensor

Heat Addition

Temperature controller

85 F

Includes a tank heater or heaters that keeps the coolant warm during process down times to avoid cold production start-up .

System Tank

New Heating Loop System Design

Temperature Sensor

Controller

90 F

To Process

Clean Supply Pump

Cooling Water

Natural GasHeater

Heat Exchanger

Coolant Circulation Pump

Hot Water Pump

Hot WaterLoop90 F

Optimal Start-up Temperature

Heat removal Heat addition

Heating Loop Detail

System Tank

Temperature Sensor

Temperature Controller

90 F

Natural GasHeater (Boiler)

Coolant Circulation Pump

Hot Water Pump

TI PI

TI PI TI PI

TI PI

PI

Pressure ReliefValve

Condensateto drain

Expansion Tank Make-Up Water Inlet

Factors In Sizing

• Warm-up time• Tank volume• Required btu’s• Hot water flow rate• Coolant flow rate

Completed Skid

Benefits to Temperature Management with Heating Loop Design

• Significant Reduction of large “cobbles”• Improved tank temperature distribution• No hot spots due to heater contact • Lower energy cost by maintaining warm• Higher production rates due to less down-time • Extended coolant life with consistent

temperatures

• Flatbed Air Vacuum Filter

Filter Types

• Liquid Vacuum Filter • Deep Bed Gravity Filter• Band Filter

Air Vacuum and Liquid Vacuum Comparison

VS

Dirty Inlet HeaderOverflow Weirs

Air Vacuum Producer

Disposable Filter Media

Media Drive

End of Media SwitchVacuum Chamber

Clean OutletCarrier Belt

Spent Media Re-winder/Sludge Separator

Tramp Oil Skimming Trough

Air Vacuum Filter

•High differential pressure is developed below the liquid pool by the vacuum producer, and is independent of process.

Liquid Vacuum Filter

Clean Supply Pump

Filter Media

Spent MediaDirty Compartment

Vacuum Chamber

Pneumatic Vacuum Break

Clean Compartment

Dirty Inlet

• The vacuum pressure is created by the pump suction and filtration is dependent on the pump

Unique Design Features

• Efficient side seals• Controlled Level lndexing feature ( CLI )

Air Vacuum Filter Side Seal DesignStainless Seal Spring

Teflon® Stationary Seal

Moving Seal

Filter MediaFlatwire Belt

Belt Support Roller

Coolant Pool

Positive Side Seals (No Migration)

Controlled Level Indexing (CLI)

• The consistent vacuum produces a uniform pressure drop across the filter media.

• And a highly efficient filter cake removes more fines that means cleaner coolant.

Solids migration is minimized as the media very slowly enters the filter

Constant Coolant Level is produced

• The consistent vacuum also means lower power consumption. • Media usage will decrease due to efficient and uniform cake

Controlled Level Indexing (CLI)

Liquid Vacuum Filter

Clean Supply Pump

Filter Media

Spent MediaDirty Compartment

Vacuum Chamber

Pneumatic Vacuum Break

Clean Compartment

Dirty Inlet

• No positive side seals

• Long index cycle of media causes solids migration

A Liquid vacuum filter has no side sealing and the discharge is very wet copper oxides

Flat Bed Air Vacuum Filter with Media Re-winder and Separator

Gravity Filters

• Band Filters• Deep bed filters• Gravity with vacuum drying

option

Band Filter

No seals and no pool depth resulting in poor filter cake production

Band Filter

Light duty construction does not meet mill high standards

GSF Gravity Filter

Deep Bed Gravity Filter With Extended Ramp & Drying

Filter Media

Flat Wire Belt Conveyor

Dirty Inlet Header

Optional Sludge Dewatering & Drying UnitExtended Drying Ramp

Clean OutletDirty Overflow

Deep Bed Liquid Pool

Having the best system possible:

• Producing higher rates • High quality rod• Less Maintenance • Increased roll life• Extended coolant life

Thank you

ReferencesThe Joe Scalise technical paper Continuous Cast and Caster Water Filtration Concepts

Gary Spence feed back on heating loop system