Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
1
Air FiltrationAir Filtration
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
2
Air filtration purposes Air filtration purposes
• To keep clean the environment To keep clean the environment for the people health and well-beingfor the people health and well-being
• To allow manufacturing process sensible to the To allow manufacturing process sensible to the impurities presenceimpurities presence
• To safe surfaces from dirtTo safe surfaces from dirt
• To safe equipment from wear, increase the lifetimeTo safe equipment from wear, increase the lifetime
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
3
The air we breatheThe air we breathe
Nitrogen 78%Nitrogen 78%
Oxygen 21%Oxygen 21% Rare gas:Rare gas:
Argon, Neon, HeliumArgon, Neon, Helium
Vapors and other gasVapors and other gas::water, methane, water, methane, carbon monoxide,carbon monoxide,ammoniac, ozoneammoniac, ozone
Atmospheric Atmospheric impuritiesimpurities::
dust, sand, marine salt, dust, sand, marine salt, spores, pollensspores, pollens
in total 1%in total 1%
(in weight at sea level)(in weight at sea level)
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
4
Treated substances Treated substances by human body in 24hby human body in 24h
Air 30-40 kgAir 30-40 kg
Liquids 3 kgLiquids 3 kg
Solids 1 kgSolids 1 kg
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
5
0.3 -1 0.3 -1 m m Tobacco smoke, bacteria, metallic fumes Tobacco smoke, bacteria, metallic fumes
10 10 m m Heavy atmospheric dust Heavy atmospheric dust
AerosolAerosol suspension suspension of some of some liquid liquid or solid or solid particles particles in the in the airair
ReferenceReferenceHuman hair:Human hair:
150 150 m approx.m approx.
25 25 m Debris and other particles visible to the naked eyem Debris and other particles visible to the naked eye
5-10 5-10 mm Molds, pollens, average atmospheric dust Molds, pollens, average atmospheric dust
1-5 1-5 m m Bacteria, light atmospheric dust Bacteria, light atmospheric dust
Size (Size (m) of m) of certain small certain small
particlesparticles
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
6
AEROSOLSAEROSOLS Suspension of some liquid or solid particles Suspension of some liquid or solid particles in the airin the air
DustsDusts Solid aerosol generated from the reduction of larger Solid aerosol generated from the reduction of larger solid solid materialmaterial
FumesFumesSolid aerosols formed by the condensation of vapors of Solid aerosols formed by the condensation of vapors of solid solid materials. materials.
FogsFogs Liquids aerosols formed by the condensation of water Liquids aerosols formed by the condensation of water vapor in the vapor in the air.air.
MistsMists Liquids aerosols formed by atomization of liquids Liquids aerosols formed by atomization of liquids
GASESGASES Any material which has the tendency to expand Any material which has the tendency to expand indefinitely and which completely and uniformly fills indefinitely and which completely and uniformly fills the container it occupiesthe container it occupies
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
7
Particle size distribution in the Particle size distribution in the atmosphereatmosphere
number of particles number of particles weightweight
0 - 1 0 - 1 mm 98.5 %98.5 %
0 - 1 0 - 1 m: m: 3%3%1 - 3 1 - 3 m: 6%m: 6%
3 - 5 3 - 5 m: 11%m: 11%
5 - 10 5 - 10 m: 52%m: 52%
10-30 10-30 m: m: 28%28%
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
8
Two types of air filtersTwo types of air filtersMechanical air filters Mechanical air filters
remove dust by capturing it on the filter media, two remove dust by capturing it on the filter media, two facts:facts:
1. The probability that a dust particle will 1. The probability that a dust particle will collide with one of the fibers of the mediacollide with one of the fibers of the media
2. The probability that the particle, once 2. The probability that the particle, once contacting the fiber filters, will continue to adhere contacting the fiber filters, will continue to adhere to it to it
Electronic air Electronic air cleaners cleaners impose a charge on dust particles impose a charge on dust particles and then set up an electrostatic field and then set up an electrostatic field to attract the particles to oppositely to attract the particles to oppositely charged collectors. They are usually charged collectors. They are usually parallel plates or a filter media parallel plates or a filter media electrostatically charged by a electrostatically charged by a continuous external power source.continuous external power source.
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
9
Principles of air filtrationPrinciples of air filtration
1. Interception 1. Interception Low speed, Low speed,
Van der Waals forcesVan der Waals forces
2. Inertial effect2. Inertial effect Increasing function of air Increasing function of air
speed, speed, particle mass, depth particle mass, depth of the filterof the filter
3. Straining3. Straining Big and fibrous particles, Big and fibrous particles,
independent of the speedindependent of the speed
4. Diffusional effect4. Diffusional effect Smallest particles, Smallest particles,
Brownian Brownian movementmovement
11
22
33
44
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
10
Gas-phase air filtration principlesGas-phase air filtration principlesAdsorptionAdsorption• Gas, vapors and liquids are attracted to and held on the surface of another Gas, vapors and liquids are attracted to and held on the surface of another substance, with atomic or molecular forces, not chemical reactions. substance, with atomic or molecular forces, not chemical reactions. • The adsorbent materials have a enormous numbers of macro and micro The adsorbent materials have a enormous numbers of macro and micro pores, with big ratio between surface and volume. F.i.: activated carbon with pores, with big ratio between surface and volume. F.i.: activated carbon with 1400 square meters per gram, activated alumina, zeolites and silica gel. 1400 square meters per gram, activated alumina, zeolites and silica gel. • Adsorption can occur wherever a material has sufficient attractive force to Adsorption can occur wherever a material has sufficient attractive force to overcome the kinetic energy of a gas molecule. The absorption of cigarette overcome the kinetic energy of a gas molecule. The absorption of cigarette smoke on the interior of an automobile or a person clothing is an example of smoke on the interior of an automobile or a person clothing is an example of absorption. absorption.
Chemical adsorption (Chemisorption)Chemical adsorption (Chemisorption)• Is the the result of chemical reactions on the surface of the adsorbent. It Is the the result of chemical reactions on the surface of the adsorbent. It depends on the chemical nature of both the adsorbent and the adsorbate. depends on the chemical nature of both the adsorbent and the adsorbate. Desorption of targets contaminants, once adsorbed and chemically reacted, Desorption of targets contaminants, once adsorbed and chemically reacted, does not occur.does not occur.
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
11
Test methods Test methods CEN EN 799 Standard CEN EN 799 Standard (Former Eurovent (Former Eurovent
EU4/5)EU4/5)
Filter on testFilter on test
Colorimetric EfficiencyColorimetric EfficiencyAtmospheric airAtmospheric air
Gravimetric ArrestanceGravimetric ArrestanceSynthetic dustSynthetic dust
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
12
Filtration Filtration ArrestanceArrestanceEfficiencyEfficiency (%)(%)
(%)(%)G1G1 Am < 65Am < 65G2G2 65 65 Am < 80 Am < 80G3G3 80 80 Am < 90 Am < 90G4G4 90 90 AmAm
F5F5 40 40 Em Em <<6060F6F6 60 60 Em < 80 Em < 80F7F7 80 80 Em < 90 Em < 90F8F8 90 90 Em < 95 Em < 95F9F9 95 95 Em Em
CEN EN 799 Standard CEN EN 799 Standard (Former Eurovent EU4/5)(Former Eurovent EU4/5)
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
13
Filtration Filtration ArrestanceArrestance ApplicationsApplicationsclassclass (%)(%) G1G1 Am < 65Am < 65 Places with fats and high Places with fats and high humidity, humidity, f.i. kitchensf.i. kitchensG2G2 65 65 Am < 80 Am < 80
G3G3 80 80 Am < 90 Am < 90 Ventilation systems for Ventilation systems for palestraepalestrae garages, industries, garages, industries, plant roomsplant rooms
G4G4 90 90 AmAm Ventilation systems for Ventilation systems for auditories,auditories,
stores, waiting rooms, stores, waiting rooms, churches, churches, courtscourts
Pre-filtersPre-filters
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
14
Filtration Filtration EfficiencyEfficiency ApplicationsApplicationsclassclass (%)(%)
F5F5 40 40 Em < 60 Em < 60 To filter smallest To filter smallest particles:particles:F6F6 60 60 Em < 80 Em < 80 big stores, bar, halls, big stores, bar, halls, F7 F7 80 80 Em < 90 Em < 90 libraries, airports libraries, airports
F8F8 90 90 Em < 95 Em < 95 Ventilation systems for: Ventilation systems for: museums, computer rooms, museums, computer rooms,
research laboratoriesresearch laboratories
F9F9 Em Em 95 95 Ventilation systems for: hospitals, Ventilation systems for: hospitals, research labs, clean zonesresearch labs, clean zones
Intermediate air filtersIntermediate air filters
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
15
Filtration Filtration EfficiencyEfficiencyApplicationsApplicationsclassclass (%)(%)
F10F10 95.00 95.00 Em < 99.90 Em < 99.90 For hospitals,For hospitals,F11F11 99.90 99.90 Em < 99.97 Em < 99.97 nuclear plants, nuclear plants, F12F12 99.97 99.97 Em < 99.99 Em < 99.99 electronic electronic devicesdevicesF13F13 99.99 99.99 Em < 99.999 Em < 99.999 manufacturing, manufacturing, F14F14 99.999 99.999 Em Em clean roomsclean rooms
High efficiency filtersHigh efficiency filtersto stop extremely fine particles, gas and smokesto stop extremely fine particles, gas and smokes
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
16
Comparative performanceComparative performancebetween the test methods for general guidance onlybetween the test methods for general guidance only
50 60 70 80 90 92 97 98 99
20 30 40 50 60 70 80 90 95 98
PERCENT ARRESTANCE (ASHRAE Standard 52.1 Test Method)
% ATMOS. DUST-SPOT EFFICIENCY (ASHRAE Standard 52.1)
G1 G2 G3 G4
F5 F6 F7 F8 F9
CEN EN 799 Standard
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
17
Filter types by configuration:Filter types by configuration:
Panel FiltersPanel Filters•Metals, natural fibers, glass fibers, Metals, natural fibers, glass fibers, synthetic fiberssynthetic fibers
• 20 20 m, m,
•Air velocity: 2-3.5 m/sAir velocity: 2-3.5 m/s
•Starting pressure drop: 10-60 Pa Starting pressure drop: 10-60 Pa
•Final pressure drop: 125-250 PaFinal pressure drop: 125-250 Pa
•Generally not renewalGenerally not renewal
•Efficient only for big particles (> 5Efficient only for big particles (> 5m)m)
Face velocity
Media velocity
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
18
Filter types by configuration:Filter types by configuration:
Pleated Panel FiltersPleated Panel FiltersExtended surface filter: Extended surface filter:
the media velocity is less than the face velocitythe media velocity is less than the face velocity
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
19
Filter types by configuration:Filter types by configuration:
Close-pleated filtersClose-pleated filtersExtended surface filter: Extended surface filter:
the media velocity is less than the face velocitythe media velocity is less than the face velocity
• By pleating paper By pleating paper media into a filter packmedia into a filter pack
•Large amount of filter Large amount of filter mediamedia
•Very low pressure Very low pressure dropdrop
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
20
Filter types by configuration:Filter types by configuration: Bag FiltersBag FiltersExtended surface filter: Extended surface filter:
the media velocity is less than the face velocitythe media velocity is less than the face velocity
•Natural fibers, glass fibers, synthetic fibersNatural fibers, glass fibers, synthetic fibers
•More pockets with one frameMore pockets with one frame
•Starting pressure drop:Starting pressure drop: 50-150 Pa50-150 Pa
•Final pressure drop: 150-300 PaFinal pressure drop: 150-300 Pa
•Not renewalNot renewal
•Efficient for particles from 1 to 5 Efficient for particles from 1 to 5 mm
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
21
Impact filter: Impact filter: dust capture mainly with impactdust capture mainly with impact
Filter types by configuration:Filter types by configuration: Grease filtersGrease filters • To prevent the grease accumulation in To prevent the grease accumulation in kitchenkitchen• Metallic (steel or aluminum) grid Metallic (steel or aluminum) grid • To be removed and washedTo be removed and washed• Low efficiency, low capacityLow efficiency, low capacity
Filter types by configuration:Filter types by configuration: Roll filtersRoll filters• Clean filter unrolled at one endClean filter unrolled at one end• Exposed at the dirty air streamExposed at the dirty air stream• Dirty media is rolled onto the second roll Dirty media is rolled onto the second roll • Glass fibers or synthetic media panelsGlass fibers or synthetic media panels• Rolling speed as a function of the pressure Rolling speed as a function of the pressure drop drop
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
22
LEGENDALEGENDA
1) Fan1) Fan
2) Electrical 2) Electrical panelpanel
3) Finned coil3) Finned coil
4) Air filter4) Air filter
5) 5) CompressCompressoror
Und
er
mod
el
Und
er
mod
el
11
22
44
33
55
Over
mod
el
Over
mod
el
2211
33
44
55
HimodCyclone of Innovations
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
23
Clogged filter alarm (opt.) Clogged filter alarm (opt.) Into our units can be Into our units can be
installed a settable differential pressostat in installed a settable differential pressostat in order to have from the microprocessor order to have from the microprocessor control the warning about the needed control the warning about the needed
change of the clogged filters. change of the clogged filters. Range: 80-600 PaRange: 80-600 Pa
Differential manometer (opt.) Differential manometer (opt.) Into our units can Into our units can
be installed a differential manometer in be installed a differential manometer in order to know the current pressure drop order to know the current pressure drop
across the filteracross the filter
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
24
Air velocity across the filtersAir velocity across the filters Unit Unit Surface Air flow Surface Air flow
VelocityVelocity(m(m22)) (m(m33/s)/s) (m/s)(m/s)
HiflexHiflex
4SUA/4LUA4SUA/4LUA 0.2480.248 0.46-0.640.46-0.64 1.85 - 1.85 - 2.582.58
8SUA/8LUA8SUA/8LUA 0.4380.438 1.21 - 1.311.21 - 1.31 2.76 - 2.992.76 - 2.99
HimodHimod
20UA20UA 0.7160.716 1.4531.453 2.032.03
40UA40UA 1.4331.433 3.1693.169 2.212.21
Mod. 2 Sub.5, MS
Air FiltrationAir Filtration
25
EnclosuresEnclosures