the concept of the basic liquid

創新需求需求再造The Concept of the Basic

Liquid

主講人 : 龍仁生

技術研討資料

創新需求需求再造

Topics The key point to the filter Filter Cartridge

Filter type Depth fiber, Membrane, Hollow Fiber…

Filter Device Membrane, Support…

Membrane Characteristic Retention Wet-ability --- De-wet

Filter Housing SS, PFA, PVDF,PP…

How to choice an optimal filter


The key to filter in Chemica • The Filter pore size / Retention

– How much ? 0.1um, 0.2um…

– Lower filtration rate, Higher retention

• The Chemical Compatibility / Pre-wetting – PTFE

– UPE

– PP

– Nylon

• Cleanness• Low Hold Volume


Typical Depth Filter Structure

創新需求需求再造Manufacturing Process

Stretched Polymeric Membranes e.g. PTFE

創新需求需求再造 Manufacturing Process

Cast Polymer Membranes e.g. PVDF


Manufacturing Process

Membranes Track Etched e.g. Polycarbonate


Membrane Characteristics

"Pore size" (maximum pore size = "retention rating )

The largest sized pores in a filter

"Porosity" A measurement of the openness of a filter i.e. 80% porosity equates to 80% open

volume, 20% material

"Pore size distribution" The range and frequency of pore sizes

which make up a the filterThat is why HA

創新需求需求再造Typical Filtration Devices:

Pleated Cartridges Filter "pack" contains membr

ane, plus upstream & downstream fibrous supports.

Supports can be a source of particles .

Pulse pressure is a potential shedding source

It is not easy to prewet and flush.

PermeateFlow Path

Inlet Flow

Path

創新需求需求再造Typical Filtration Devices:Stacked Disk Cartridges

Downstream components are rigid and cleaner than other membrane supports.

Excellent in pulse pressure shedding.

Horizontal disks prevent efficient gas venting

FluidFlowPath

Permeate


Typical Filtration Devices:Hollow Fiber Cartridges

Filter area can be greater than pleated structure

Benefits of self-supporting, high surface area, high flow.

Used mostly in water filtration and photochemical.

Low pressure drop


Capture by Sieving / Interception ---

Hard Particle--- Bridge/ Cake effectSoft –Gel/Micro-bubble

Hard ParticlesSoft Particles

Filtration Retention Mechanisms:


Retention Mechanisms:

Very small particles in liquids have a negative charge and can be captured by attraction to a positive charge in a filter

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Capture by Adhesion / Adsorption


過濾在時間的變化

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過濾

Shedding

過濾Shedding

過濾

Sheddingparticlel

Time

Time

壓差


Hydrophobic Vs Hydrophilic

Hydrophilic: Wetting smoothly with, water.". No pre-wetting

Hydrophobic: Fear of water; Tending not to combine with water. Requires pre-wetting.


Hydrophobic Vs Hydrophilic

Contact Angle is the measure of Wettability

Hydrophobic

< 90?

Hydrophilic

No contact angle 90? > 90?

Low contact angle = HydrophobicHigh contact angle = Hydrophilic

i.e.


PTFE membrane surface energy is 18 dynes/cm; PTFE has a higher affinity for air than water. Gas bubbles stick to the membrane surface, forming nucleation sites.

As more gas bubbles pass through the pore, these nucleation sites grow and begin to block the pore.

Finally, the pore completely fills with gas, effectively blocking the pore and rendering it unusable. As more pores in the filter dewet, the flow through the filter dramatically decreases.

What is Dewetting and how can it impact a process?

SC1SC2H2O2

NH4FPiranha


QuickChange membrane surface energy is 35 dynes/cm; when wet, this membrane has a higher affinity for water than air.

Dissolved gas bubbles do not stick to the membrane surface, eliminating the formation of nucleation sites.

Dissolved gas bubbles are swept through the pore, leaving the usable filtration area intact. Flow rates are maintained over extended periods in use.

QuickChange Filters are Non-Dewetting

SC1SC2H2O2

NH4FPiranha

Non-Dewetting Technology


Flow in one direction (prevents air entrapment) Flow from upstream side into core 60:40 IPA water solution Flush with DI water

Prewetting

Vent

Drain


Filter Housing

POU typically single 10" filter housing

Materials of construction: PFA, PVDF, PP, SS


Filter Cartridge Housing

T-Line Design In-line DesignInlet

Outlet

Typical Flow Path

Inlet Outlet


T-Line Mounting Considerations

Bowl Down (top of the head points toward ceiling)

Easier to drain upstream side of filter

Air does not get trapped in core

– Liquid remains in core after drain

– 20" can be difficult to mount filters

Inlet Outlet


T-Line Mounting Considerations

Bowl Up (top of the head points towards the floor)

Complete draining of filter core Easy filter installation Recommended configuration for 20"

housings

– Liquid drains from upstream side of filter

– Must vent downstream side of housing

Vent

Drain

創新需求需求再造Reduced Tool Space Required

• A typical tool design requires enough space to lower the bowl below the cartridge for filter changeout.

• With Chemlock, the bowl only needs to be lowered below the head, then the cartridge and bowl can be removed as a single unit.

• Tool Space Savings - Approx. ~ 8 inches!

• 18” in space savings with 20” bowl

創新需求需求再造Typical Disposable Filter

Assembly

Connections : Flartek, Butt Weld, etc.

Vent

Drain

inlet

outlet

Internal Filter Element


Disposables Vs. Housings

Disposables More compact footprint Cleaner

no o-rings/seals no handling of eleme

nt Easier for prewetting Improved safety Higher Temps ( 180C )

Housings Traditional design Flexibility - 4" -

40" Requires O-ring

change Increased

contamination risk Greater material

selection Easier

customization Limited Temp

( ~100C )


Variables Which Effect Retention

Membrane Contaminant Fluid Conditions

Structure- cast- stretched- irradiated

Charge

Pore size & pore size distribution.

Porosity*ThicknessEtc.

REF.<C01>Type:- solvent- acid- base- mixture

Viscosity*

Flow rate/face velocity

Temperature

Pressure: - pulse- differential


Summary Five major filtration mechanism

1.Cake filtration 2.Size exclusion 3.interception 4.adhesion 5.adsorption

Two major filter types Depth filter—Pre filter-dirty process Membrane filter – Final filter-precision filtration

Filter Wetability Hydrophobic membrane – used for solvent

Hydrophilic membrane –Not need to prewet for water base chemical

Filter Retention Defined by pore size and LRV Affected by Pore size distribution and pore size definition

the concept of the basic liquid

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