AIR FILTRATION SYSTEMS AND DUST AIR FILTRATION SYSTEMS AND DUST COLLECTORSCOLLECTORS

PRESENTED BYPRESENTED BY

G.RAMYAG.RAMYA

HT.NO.256212886042HT.NO.256212886042 MPHARMMPHARM DEPARTMENT OF PHARMACEUTICSDEPARTMENT OF PHARMACEUTICS

CONTENTSCONTENTS

1. INTRODUCTION1. INTRODUCTION

2. MECHANISM OF AIR FILTRATION2. MECHANISM OF AIR FILTRATION

3. EVALUATION OF AIR FILTRATION3. EVALUATION OF AIR FILTRATION

4. TYPES OF AIR FILTERS4. TYPES OF AIR FILTERS

5. HEPA FILTERS5. HEPA FILTERS

6. DUST COLLECTORS6. DUST COLLECTORS

7. TYPES OF DUST COLLECTORS7. TYPES OF DUST COLLECTORS

8. APPLICATIONS OF DUST COLLECTORS8. APPLICATIONS OF DUST COLLECTORS

INTRODUCTIONINTRODUCTION

Air filtration is an important aspect of air conditioning in Air filtration is an important aspect of air conditioning in pharmaceutical industry. pharmaceutical industry.

The main aim of air filtration is to produce a dust free atmosphere The main aim of air filtration is to produce a dust free atmosphere where the products can be handled in clean conditions or for the where the products can be handled in clean conditions or for the development of sterile environment for carrying out various development of sterile environment for carrying out various aseptic processes. aseptic processes.

Areas like spray drying, fluid bed drying, coating, granulating, Areas like spray drying, fluid bed drying, coating, granulating, milling and packaging, dust collecting require air filtration. milling and packaging, dust collecting require air filtration.

REQUIREMENTS OF AIRREQUIREMENTS OF AIR

Air in controlled environment should have: Air in controlled environment should have:

A per cubic foot particle count of not more than 100,000 in a size A per cubic foot particle count of not more than 100,000 in a size range of 0.5 micron and larger when measured with automatic range of 0.5 micron and larger when measured with automatic counters or 700 particles in a size range of 5.0 microns or larger counters or 700 particles in a size range of 5.0 microns or larger when measure by a manual microscopic method.when measure by a manual microscopic method.

A temperature of 72 F ± 5 or 22 C ± 3. A temperature of 72 F ± 5 or 22 C ± 3.

A maximum relative humidity of 50% and a minimum of 30%. a A maximum relative humidity of 50% and a minimum of 30%. a positive pressure differential of at least 0.05 inch of water with all positive pressure differential of at least 0.05 inch of water with all doors closed in relation to less clean adjacent areas. At least 20 air doors closed in relation to less clean adjacent areas. At least 20 air changes per hour.changes per hour.

FILTER CLASSIFICATIONFILTER CLASSIFICATION

Based on type of collection method used, air filters can be Based on type of collection method used, air filters can be classified asclassified as

SeivingSeiving

DynamicDynamic

MECHANISM OF AIR FILTRATIONMECHANISM OF AIR FILTRATION

Impingement Impingement

This type of filtration is also called as inertial impaction which This type of filtration is also called as inertial impaction which refers to the capture of particles due to the inability of the particle refers to the capture of particles due to the inability of the particle to deviate from change in the flow path due to inertia. to deviate from change in the flow path due to inertia.

This is efficient at high velocities and not suitable for very small This is efficient at high velocities and not suitable for very small particles (of size less than 5 microns). particles (of size less than 5 microns).

DiffusionDiffusion This is also called as Brownian motion (disorganised motion) This is also called as Brownian motion (disorganised motion)

resulting in the movement of particles from molecular collisions.resulting in the movement of particles from molecular collisions.

Efficient method even for particles of size less than 1 microns in Efficient method even for particles of size less than 1 microns in

low velocities. low velocities.

InterceptionInterception

Most commonly affects particles above 0.4 microns. The Most commonly affects particles above 0.4 microns. The particle sticks to one of the filter's fibers after coming close particle sticks to one of the filter's fibers after coming close enough to it.enough to it.

It is as if the fiber reaches out and catches the particle. It is as if the fiber reaches out and catches the particle.

Electrostatic forcesElectrostatic forces

Particles can be retained by controlling the polarity of the Particles can be retained by controlling the polarity of the filter medium by the action of electrostatic forces.filter medium by the action of electrostatic forces.

These forces vary inversely with the air velocity and the These forces vary inversely with the air velocity and the dimensions of the particle.dimensions of the particle.

EVALUATION OF AIR FILTER SYSTEMSEVALUATION OF AIR FILTER SYSTEMS

Airflow resistanceAirflow resistance

Filter efficiencyFilter efficiency

Service lifeService life

ArrestanceArrestance

EVALUATING AIRFLOW RESISTANCEEVALUATING AIRFLOW RESISTANCE

Optimum filter should provide highest efficiency with the Optimum filter should provide highest efficiency with the lowest resistance to the airflow.lowest resistance to the airflow.

It is measured in inches of water column height by using a It is measured in inches of water column height by using a manometer.manometer.

The pressure drop is proportional to the efficiency of the filter The pressure drop is proportional to the efficiency of the filter and to the airflow pressure.and to the airflow pressure.

EVALUATING FILTER EFFICIENCYEVALUATING FILTER EFFICIENCY

..

TESTTEST CHALLENGECHALLENGE FILTER FILTER TYPETYPE

FILTER FILTER MATERIALMATERIAL

AFI(granuloAFI(granulometric)metric)

DustDust Low efficiencyLow efficiency Natural & Natural & nonwoven nonwoven fibers, metalfibers, metal

ASHRAE 52-ASHRAE 52-76(colorimetr76(colorimetric)ic)

Atmospheric airAtmospheric air Medium Medium efficiencyefficiency

Fiberglass, Fiberglass, synthetic fiberssynthetic fibers

DOP(photomDOP(photometric)etric)

DOP aerosolDOP aerosol High efficiencyHigh efficiency Microfiber Microfiber glassglass

EVALUATING SERVICE LIFEEVALUATING SERVICE LIFE

The life of a filter is directly proportional to its capacity to The life of a filter is directly proportional to its capacity to retain the constituents.retain the constituents.

The service life of a filter is predicted by monitoring the The service life of a filter is predicted by monitoring the pressure drop increase.pressure drop increase.

Manufacturers specify the differential pressure range Manufacturers specify the differential pressure range indicative of the useful life of a filter.indicative of the useful life of a filter.

For high efficiency filters the service life can be extended to For high efficiency filters the service life can be extended to 3years.3years.

EVALUATING ARRESTANCEEVALUATING ARRESTANCE

Arrestance is defined as the capacity of the filter to retain dust.Arrestance is defined as the capacity of the filter to retain dust.

The filter arrestance is determined by the factor, filter design The filter arrestance is determined by the factor, filter design which is a function of the filter medium used(in ftwhich is a function of the filter medium used(in ft²² or m or m²²) and ) and the way the medium is pleated.the way the medium is pleated.

The more medium a filter has, the higher is its arrestance.The more medium a filter has, the higher is its arrestance.

TYPES OF AIR FILTRATIONTYPES OF AIR FILTRATION

Various types of air filters being used in the Various types of air filters being used in the pharmaceutical industry are: pharmaceutical industry are:

High efficiency particle air filters (HEPA). High efficiency particle air filters (HEPA). Packed towers.Packed towers. Membrane filter cartridges. Membrane filter cartridges. Hydrophobic filters. Hydrophobic filters.

HEPA FILTERSHEPA FILTERS

It has the capability of retaining particles as small as 0.3It has the capability of retaining particles as small as 0.3µm µm with a minimum efficiency of 99.97%.with a minimum efficiency of 99.97%.

Filter medium consists of fine glass fiber(0.1Filter medium consists of fine glass fiber(0.1µmµm) as high as ) as high as 99% and 1% binders.99% and 1% binders.

Allows the retention of small particles by Brownian diffusion.Allows the retention of small particles by Brownian diffusion.

Provides the interception by inertial effect of particles of Provides the interception by inertial effect of particles of intermediate size.intermediate size.

Provides a seiving effect for large particles.Provides a seiving effect for large particles.

HEPA FILTER CONSTRUCTIONHEPA FILTER CONSTRUCTION

The basic components of HEPA filter are:The basic components of HEPA filter are:

1. Frame1. Frame

2. Filter medium2. Filter medium

3. Separators3. Separators

4. Adhesive4. Adhesive

5. Gasket5. Gasket

HEPA FILTER CONSTRUCTIONHEPA FILTER CONSTRUCTION

HEPA filter is constructed of borosilicate micro fibers in the form HEPA filter is constructed of borosilicate micro fibers in the form of pleated sheet.of pleated sheet.

Sheet is pleated to increase the overall filtration surface area. The Sheet is pleated to increase the overall filtration surface area. The pleats are separated by serrated aluminum baffles or stitched pleats are separated by serrated aluminum baffles or stitched fabric ribbons, which direct airflow through the filter.fabric ribbons, which direct airflow through the filter.

This combination of pleated sheets and separators acts as This combination of pleated sheets and separators acts as filtration medium. filtration medium.

It is installed into an outer frame made of fire-rated particle It is installed into an outer frame made of fire-rated particle board, aluminum, or stainless steel. The frame-media junctions board, aluminum, or stainless steel. The frame-media junctions are bonded with an adhesive. are bonded with an adhesive.

HEPA FILTER TESTINGHEPA FILTER TESTING

EFFICIENCY TESTING (HOT DOP TEST):EFFICIENCY TESTING (HOT DOP TEST):

This method uses a monodisperse aerosol of DOP of 0.3This method uses a monodisperse aerosol of DOP of 0.3µm µm diameter particles.diameter particles.

The uniformity of aerosol must be generated by vaporizing DOP The uniformity of aerosol must be generated by vaporizing DOP and then condensing it to the desired size.and then condensing it to the desired size.

An aerosol photometer is used to measure aerosol concentration An aerosol photometer is used to measure aerosol concentration upstream and downstream to obtain the difference.upstream and downstream to obtain the difference.

INTEGRITY TESTING (COLD DOP TEST)INTEGRITY TESTING (COLD DOP TEST)

Polydisperse aerosol is used and is generated by pumping Polydisperse aerosol is used and is generated by pumping pressurized air into a vessel containing room temperature DOP and pressurized air into a vessel containing room temperature DOP and this mixture is released through a nozzle with a calibrated orifice.this mixture is released through a nozzle with a calibrated orifice.

This is used to assess the integrity of the filter medium, the This is used to assess the integrity of the filter medium, the adhesives, the filter housing.adhesives, the filter housing.

APPLICATIONSAPPLICATIONS

HEPA filters are critical in the prevention of the spread of airborne HEPA filters are critical in the prevention of the spread of airborne bacterial and viral organisms and, therefore, infection.bacterial and viral organisms and, therefore, infection.

Typically, medical-use HEPA filtration systems also incorporate Typically, medical-use HEPA filtration systems also incorporate high-energy ultra-violet light units to kill off the live bacteria and high-energy ultra-violet light units to kill off the live bacteria and viruses trapped by the filter media. viruses trapped by the filter media.

Some of the best-rated HEPA units have an efficiency rating of Some of the best-rated HEPA units have an efficiency rating of 99.995%, which assures a very high level of protection against 99.995%, which assures a very high level of protection against airborne disease transmission.airborne disease transmission.

Biological safety cabinetBiological safety cabinet

Chemical industry Chemical industry

Hospital operating rooms Hospital operating rooms

Emergency burn centers Emergency burn centers

Medical industry Medical industry

Food industryFood industry

LIMITATIONSLIMITATIONS

HEPA filters only target airborne particles, not gasses. HEPA filters only target airborne particles, not gasses.

HEPA filters also tend to be more expensive than other filters. HEPA filters also tend to be more expensive than other filters.

Filters will almost always need to be regularly replaced at Filters will almost always need to be regularly replaced at least once or twice a year, as well, meaning that there is an least once or twice a year, as well, meaning that there is an extra recurring cost in addition to the initial price of the extra recurring cost in addition to the initial price of the purifier.purifier.

PACKED TOWERSPACKED TOWERS

Packed towers are custom-designed to provide removal efficiencies Packed towers are custom-designed to provide removal efficiencies in the range of 95% to 99% for acid and toxic gases with a low in the range of 95% to 99% for acid and toxic gases with a low pressure drop.pressure drop.

MEMBRANE FILTER CARTRIDGESMEMBRANE FILTER CARTRIDGES

These are compact, easily handled and can be manufactured as fully These are compact, easily handled and can be manufactured as fully disposable form. disposable form.

Designed in the form of cylinder made of polypropylene fabric Designed in the form of cylinder made of polypropylene fabric material.material.

These are available as either pre filter (particulate and liquid These are available as either pre filter (particulate and liquid aerosol) or sterilizing filter (bacterial contaminants).aerosol) or sterilizing filter (bacterial contaminants).

HYDROPHOBIC FILTERSHYDROPHOBIC FILTERS

These are generally used as vent filters.These are generally used as vent filters.

They protect the contents of the containers against contamination They protect the contents of the containers against contamination by addition or with drawl of the stored liquids in the air which by addition or with drawl of the stored liquids in the air which enters or leaves them.enters or leaves them.

DUST COLLECTORSDUST COLLECTORS

A A dust collectordust collector is a system used to enhance the quality of air is a system used to enhance the quality of air released from industrial and commercial processes by released from industrial and commercial processes by collecting dust and other impurities from air or gas. collecting dust and other impurities from air or gas.

Designed to handle high-volume dust loads, a dust collector Designed to handle high-volume dust loads, a dust collector system consists of a system consists of a

BlowerBlower Dust filter Dust filter Filter-cleaning system, Filter-cleaning system, Dust receptacle or dust removal system. Dust receptacle or dust removal system.

OBJECTIVESOBJECTIVES

Protection of the operator.Protection of the operator.

Protection of the production equipment from dust. Protection of the production equipment from dust.

Protection of the pharmaceutical product from the effects of Protection of the pharmaceutical product from the effects of dust. dust.

Protection of quality of environment in a premises. Protection of quality of environment in a premises.

Recovery of the expensive materials. Recovery of the expensive materials.

CHOICE OF A DUST COLLECTORCHOICE OF A DUST COLLECTOR

Dust collectors vary widely in design, operation, effectiveness, Dust collectors vary widely in design, operation, effectiveness, space requirements, construction, and capital, operating, and space requirements, construction, and capital, operating, and maintenance costs. maintenance costs.

The selection of a dust collector should be based on the The selection of a dust collector should be based on the following general factors: following general factors:

Dust concentration and particle size. Dust concentration and particle size. Degree of dust collection required. Degree of dust collection required. Characteristics of airstream. Characteristics of airstream. Characteristics of dust. Characteristics of dust. Methods of disposal. Methods of disposal.

TYPES OF DUST COLLECTORTYPES OF DUST COLLECTOR

Five principal types of industrial dust collectors are:Five principal types of industrial dust collectors are:

1. Inertial separators1. Inertial separators

2. Fabric filters2. Fabric filters

3. Wet scrubbers3. Wet scrubbers

4. Electrostatic precipitators4. Electrostatic precipitators

5. Unit collectors5. Unit collectors

INERTIAL SEPARATORSINERTIAL SEPARATORS

Inertial separators separate dust from Inertial separators separate dust from gas streams using a combination of gas streams using a combination of forces, such as centrifugal, forces, such as centrifugal, gravitational, and inertial. gravitational, and inertial.

These forces move the dust to an area These forces move the dust to an area where the forces exerted by the gas where the forces exerted by the gas stream are minimal. stream are minimal.

The separated dust is moved by The separated dust is moved by gravity into a hopper, where it is gravity into a hopper, where it is temporarily stored. temporarily stored.

FABRIC FILTERSFABRIC FILTERS

Commonly known as baghouses.Commonly known as baghouses.

Fabric collectors use filtration to Fabric collectors use filtration to separate dust particulates from separate dust particulates from dusty gases. dusty gases.

They are one of the most efficient They are one of the most efficient and cost effective and can achieve and cost effective and can achieve a collection efficiency of more a collection efficiency of more than 99% for very fine particulates.than 99% for very fine particulates.

AdvantagesAdvantages

Can handle varying exhaust gas flow rates & particle loading.Can handle varying exhaust gas flow rates & particle loading.

ProblemsProblems

Bag failure Bag failure Abrasion Abrasion Chemical degradation of fabric Chemical degradation of fabric Exceeding temperature limit of fabric Exceeding temperature limit of fabric

WET SCRUBBERSWET SCRUBBERS

Dust collectors that use liquid are known as wet scrubbers.Dust collectors that use liquid are known as wet scrubbers.

In these systems, the scrubbing liquid (usually water) comes into In these systems, the scrubbing liquid (usually water) comes into contact with a gas stream containing dust particles.contact with a gas stream containing dust particles.

Greater contact of the gas and liquid streams yields higher dust Greater contact of the gas and liquid streams yields higher dust removal efficiency. removal efficiency.

WET SCRUBBERSWET SCRUBBERS

There is a large variety of wet scrubbers however, all have one of There is a large variety of wet scrubbers however, all have one of two basic configurations:two basic configurations:

1. 1. Gas-humidificationGas-humidification - The gas-humidification process - The gas-humidification process agglomerates fine particles, increasing the bulk, making collection agglomerates fine particles, increasing the bulk, making collection easier.easier.

2. 2. Gas-liquid contactGas-liquid contact - This is one of the most important factors - This is one of the most important factors affecting collection efficiency. The particle and droplet come into affecting collection efficiency. The particle and droplet come into contact by four primary mechanismscontact by four primary mechanisms

• Inertial impactionInertial impaction• InterceptionInterception• DiffusionDiffusion• Condensation nucleationCondensation nucleation

ELECTROSTATIC PRECIPITATORSELECTROSTATIC PRECIPITATORS

MechanismMechanism Ionizing the gas. Ionizing the gas.

Charging the dust particles.Charging the dust particles.

Transporting the particles to Transporting the particles to the collecting surface.the collecting surface.

Neutralizing the dust particles.Neutralizing the dust particles.

Removing the dust from the Removing the dust from the collecting surface. collecting surface.

ELECTROSTATIC PRECIPITATORSELECTROSTATIC PRECIPITATORS

Types Types i ) Cottrell or Single-stage - Combines ionization and collection i ) Cottrell or Single-stage - Combines ionization and collection

in a single stagein a single stage ii ) Penny or Two-stage - Ionization and collection in different ii ) Penny or Two-stage - Ionization and collection in different

stages stages

Advantages Advantages Large gas volumes & high collection efficiency for small Large gas volumes & high collection efficiency for small

particles needed.particles needed.

Problems Problems Not suited where exhaust gas is flammable or explosive.Not suited where exhaust gas is flammable or explosive. Lose of efficiency between cleaning cycles if not maintained Lose of efficiency between cleaning cycles if not maintained

properly. properly.

UNIT COLLECTORSUNIT COLLECTORS

A number of designs available having capacities in the range A number of designs available having capacities in the range 200 – 2000ft³/min. 200 – 2000ft³/min.

There are two main types of unit collectorsThere are two main types of unit collectors

Small fabric collectors used for fine dust.Small fabric collectors used for fine dust. Cyclone collectors used for coarse dust Cyclone collectors used for coarse dust

APPLICATIONSAPPLICATIONS

Many industrial processes likeMany industrial processes like

MillingMilling

Grinding Grinding

Abrasive Abrasive

Blasting Blasting

Welding , etc. uses dust collectors to improve quality of air Welding , etc. uses dust collectors to improve quality of air inside the plant applications. inside the plant applications.

REFERENCESREFERENCES

Pharmaceutical Dosage Forms, Parenteral medications, vol 2 Pharmaceutical Dosage Forms, Parenteral medications, vol 2 by K.E.Avis, Marcel Dekker, NY. Page No. 416-438.by K.E.Avis, Marcel Dekker, NY. Page No. 416-438.

The theory and Practice of Industrial Pharmacy, L.Lachman, The theory and Practice of Industrial Pharmacy, L.Lachman, A.Liberman, L.Kanig. Page No. 736-739.A.Liberman, L.Kanig. Page No. 736-739.

www.dustcollectorexperts.comwww.dustcollectorexperts.com