Post on 27-Jan-2016
description
FOG & HAZEFOG & HAZELooking into understanding Looking into understanding
fog and its various fog and its various applications.applications.
Presenter: Thierry PouliotPresenter: Thierry Pouliot
What is Fog?What is Fog? Meteorological phenomenonMeteorological phenomenon
Water dropletsWater droplets Fine ice crystalsFine ice crystals
Near-freezing air temperatureNear-freezing air temperature Water saturationWater saturation
How does it happen?How does it happen?
3 common types of fog3 common types of fog
Advection fogAdvection fog
Radiation fogRadiation fog
Evaporation fogEvaporation fog
Advection FogAdvection Fog
Vapor condensation Vapor condensation around dust particlesaround dust particles
Warm air blown Warm air blown across a cool across a cool surface, like wind surface, like wind from the oceanfrom the ocean
Creates fogCreates fog
Radiation FogRadiation Fog
Cool GroundCool Ground Warm airWarm air Vapor condensation Vapor condensation
around dust particlesaround dust particles
Creates fogCreates fog
Evaporation FogEvaporation Fog
Additional water vapor Additional water vapor enters an already enters an already saturated air near saturated air near maximum vapor maximum vapor pressure (Kpa) pressure (Kpa)
The air is cooled down to The air is cooled down to dew pointdew point
Creates fogCreates fog
Natural fog vs Artificial fogNatural fog vs Artificial fog
Comes mostly from Comes mostly from water water evaporation and evaporation and stagnant particlesstagnant particles
Is affected by air Is affected by air temperature, temperature, barometric pressure, barometric pressure, wind speed and water wind speed and water saturation.saturation.
May come from May come from pollution!pollution!
Comes from various Comes from various chemicals and chemicals and processesprocesses
Is affected by air Is affected by air temperature, temperature, barometric pressure, barometric pressure, wind speed and water wind speed and water saturation.saturation.
May cause pollution!May cause pollution!
Creating artificial fogCreating artificial fog
Creating fog requires 3 key elements:Creating fog requires 3 key elements:
A Method of productionA Method of production
Some form of chemical compoundSome form of chemical compound
Ambiant air supportAmbiant air support
Methods of productionMethods of production
Fog / Haze GeneratorFog / Haze Generator
Fog / Haze MachineFog / Haze Machine
« Cracker »« Cracker »
OthersOthers
Fog Generators vs Fog MachinesFog Generators vs Fog Machines
Quiet!Quiet! Constant outputConstant output 100% duty cycle100% duty cycle Gas Gas used as:used as:
– Non-flammable Non-flammable propellantpropellant
– PurgePurge– Fog Fog dispersiondispersion
LouderLouder Pressure Pressure variationvariation Sometimes needs a Sometimes needs a
pause to reheatpause to reheat.. No gas requiredNo gas required
« Crackers »« Crackers » Thermal cracking: petrochemical industry…Thermal cracking: petrochemical industry…
… … or the nuclearor the nuclear
So, « Crackers »?So, « Crackers »?
Cracking modifies chemicals at the Cracking modifies chemicals at the molecularmolecular level level
Cracking requires Cracking requires very highvery high operating operating temperature and / or pressuretemperature and / or pressure
Artificial fog chemical compoundsArtificial fog chemical compounds
MINERAL OIL BASEMINERAL OIL BASE
- Inert chemical - Inert chemical compoundcompound
- Byproduct of - Byproduct of petroleum distillationpetroleum distillation
- Can be broken into - Can be broken into microscopic particlesmicroscopic particles
- Light weight- Light weight
- Long lasting- Long lasting
GLYCOL BASEGLYCOL BASE
- Disperses heat - Disperses heat rapidlyrapidly
- Hygroscopic - Hygroscopic chemical compoundchemical compound
-Heavier than oilHeavier than oil
-Larger particlesLarger particles
-Short life as fogShort life as fog
OTHERSOTHERS
GlycerolGlycerol
(GLYCERIN)(GLYCERIN)
Potassium Nitrate Potassium Nitrate (SALTPETRE)(SALTPETRE)
Mineral oil-based fluidMineral oil-based fluid
MDG Neutral (suitable MDG Neutral (suitable for standard MAXfor standard MAX™ ™ and ATM™ series).and ATM™ series).
Odourless and insipid.Odourless and insipid. Produces fine particles (0.5 ~ Produces fine particles (0.5 ~
0.7µm)0.7µm) Long hang time (Brownian Long hang time (Brownian
Motion) – low gravitational Motion) – low gravitational pullpull
Low coalescence, high Low coalescence, high dispersion.dispersion.
Mineral oil?Mineral oil?
Inert, non-reactive, non-irritant Inert, non-reactive, non-irritant Used as a medically-supervised laxativeUsed as a medically-supervised laxative Main ingredient in Baby oil / lotionsMain ingredient in Baby oil / lotions Cosmetic cold creams, make-up removerCosmetic cold creams, make-up remover Used as a machanical lubricant / coolantUsed as a machanical lubricant / coolant Used as a preservative (lithium) and Used as a preservative (lithium) and
oxydation inhibitor (nihontoxydation inhibitor (nihontō)ō) Aka - Paraffin, Petrol gellyAka - Paraffin, Petrol gelly
Glycol-Based fluidGlycol-Based fluid
MDG LOW FOG fluid MDG LOW FOG fluid (suitable for standard Ice-(suitable for standard Ice-FogFog™ series) and MDG ™ series) and MDG DENSE or WB2 fluid DENSE or WB2 fluid (suitable for standard (suitable for standard MM™ series).MM™ series).
Distinctive smell, acrid tasteDistinctive smell, acrid taste Produces larger particles (2.5 ~ Produces larger particles (2.5 ~
20 µm)20 µm) Variable hang time Variable hang time Higher coalescence, high Higher coalescence, high
dispersion.dispersion.
Glycol?Glycol?
2 main types used in fog: Diethylene and 2 main types used in fog: Diethylene and Propylene Glygols Propylene Glygols
Hygroscopic compoundHygroscopic compound Fast heat dissipationFast heat dissipation
Other uses of GlycolsOther uses of Glycols
Industrial coolantIndustrial coolant Automotive coolantAutomotive coolant Anti-perspirantAnti-perspirant Componant in the manufacturing of resins, Componant in the manufacturing of resins,
polyesters, explosives, and vaccinespolyesters, explosives, and vaccines Used as a preservative to replace Used as a preservative to replace
formaldehyde. formaldehyde.
Safety StandardsSafety Standards
Using your fog machine / cracker / generatorUsing your fog machine / cracker / generator
NEVER NEAR PEOPLENEVER NEAR PEOPLE– Most fog machines operate either under pressure Most fog machines operate either under pressure
or at high temperatures. or at high temperatures. – Most fogs are still in a liquid state (Wet Fog)Most fogs are still in a liquid state (Wet Fog)– Most fogs are hot near nozzle / exit portMost fogs are hot near nozzle / exit port– ALL FOGS LEAVE RESIDUESALL FOGS LEAVE RESIDUES
INERT GASESINERT GASES
Unlike Noble gases, Inert gases are not Unlike Noble gases, Inert gases are not necessarily elemental.necessarily elemental.
Most are compoundsMost are compounds Complete valence electron (last orbit full)Complete valence electron (last orbit full)
Inert gases: Helium and Neon (elemental) Inert gases: Helium and Neon (elemental) Carbon Dioxide (COCarbon Dioxide (CO22)and Nitrogen (N)and Nitrogen (N22))
Inert gases usageInert gases usage
Non-flammableNon-flammable Readily available everywhereReadily available everywhere Relatively cheapRelatively cheap Standard safety code throughout the EUStandard safety code throughout the EU
Fog applications:Fog applications:
•First Response TrainingFirst Response Training
Final tip of the dayFinal tip of the day
LESS IS MORELESS IS MORE