Smoke Studies and Airflow Visualization Studies using Cleanroom Foggers
Portable Clean Room Fogger for Fume Hoods and Airflow Hoods. Find the highest quality SMST-12 clean room fogger machine & portable fogger from Applied Metrology LLC. Request a quote for our cleanroom fogger machines used in sterile rooms for smoke studies of airflow turbulence. The portable cleanroom fogger is used in smoke studies with DI Water (De-ionized water), Sterile water or WFI (Water for Injection) water to generate about 0.5 cubic meters of fog per minute. Fog density is about 100 milli-liters consumption per minute. The SMST-12 is a low cost fogger that operates for a typical 45 minutes per water fill cycle. The SMST-12 fogger produces a constant fog density, thus the fog volume produced is also constant, but the SMST-12 allows velocity control via push button controls on the fogger interface, and also allows remote control of fog on/off and velocity control via optional wireless control. The fog vapor is composed of water droplets that are about 8-10 microns in diameter; thus as the fog vapor travels thru the airflow, it begins to evaporate. The visual fog evaporates after about 6-7 feet. No particle contaminants are created or left in the airflow. No cleanup is required other than a general wipe down of pure moisture. And the fog is composed of the same elements that we breathe, so walking thru a clean room fog is nearly identical to fog encountered in weather. Clean room foggers use deionized water, sterile water or water for injection; thus the water is quite pure. The fog can easily visualize turbulence and airflow patterns in Fume Hoods, Airflow Hoods or small Glovebox. Balance of air pressure can be visually described between two clean areas, such as a barrier isolator and sterile room. Bio-safety cabinets and glove boxes can be tested for proper airflow.
SMST-12 Clean Room Fogger ≈ 0.5 cubic meters fog / minute, ≈ 45 minutes operation, ≈ 6-7 feet fog visibility with one 80mm fog outlet, Accessories optional
Table of Contents
The SMST-12 Cleanroom Fogger for Smoke Studies will support low cost requirements for airflow visualization studies and smoke studies in small area environments. This small, portable, easy to use smoke machine will support your requirements to test airflow in fume hoods, airflow hoods, small glove boxes and similar sized volumetric areas to visually describe airflow patterns, airflow turbulence or uniformity in controlled airflows. Most Engineers and technicians in the pharmaceutical industry use testing guidelines, such as ISO 14644-3, Annex B.7 Airflow Direction Test and Visualization. Another guideline is USP 797 Insitu Airflow Analysis. Semiconductor companies are now starting to use the same ISO 14644 guidelines for clean room airflow tests. The SMST-12 Smoke Studies Fogger can also be used to evaluate how fast a clean room recovers from a particle challenge, as guided by ISO 14644-3, Annex B12 Airflow Recovery Test. Polystyrene latex spheres are typically used specific size peaks of 0.5 micron, 1 micron or 2 microns. The SMST-12 Cleanroom Fogger is used to create the aerosol particle challenge into the sterile room or ISO suite, then air particle counters are used to monitor how quickly the clean room returns to normal after introduction of the particle challenge.
Ultrasonic DI Water foggers can be easily compared in fog performance per dollar cost by calculating the actual fog density over time!
Fog volume, fog density and visual airflow distance are the 3 major elements of a fogger, yet rarely discussed by companies producing clean room smoke machines. Fog density is a measure of how many liters of liquid is converted to a visual fog per minute. The diameter of the fog droplets is equally important, and always controlled by the fog technique used to create the water vapor. Ultrasonic foggers, operating by cavitation in water, typically provide water droplet diameter from 8 -10 microns in diameter. Fog density then is determined by measuring the water volume consumed per minute, typically measured in milli-liters per minute.
Ultrasonic foggers are normally built with 8 to 40 piezo devices. The SMST-12 uses 12 high performance piezos generating 76 ml of fog density and 0.5 cubic meters of fog per minute. As a comparison the AFM40 uses 40 high performance piezos operating at 2 cubic meters of pure fog per minute. The SMST-12 fog travels about 6-7 feet in a typical clean room airflow velocity of 70 fpm with a typical humidity of 40%, while the AFM40 fog travels a typical 12-15 feet using dual 80mm fog outlets. It is the fog density that controls the fog volume and visual distance of any fogger. As the fog travels through the airflow, it gradually evaporates to the same air we breathe.
Clean Room Fogger, SMST-12 Features
- 12 piezo devices produce 0.5 cubic meters of fog per minute for typical 45 minutes operation
- About 0.100 milli-liters per minute of fog density provides a typical 6-7 feet visual airflow
- Easy Fill Water Port with a fill level of 4.5 liters of Deionized water, sterile water or water for injections
- Water Level Fill Indicator is provided on left panel
- Operating instructions are provided on the right panel
- Power On and water drain are provided on the front panel
- Carry Handle provided on top for operator convenience
- Polypropylene enclosure offers a clean, lightweight enclosure
- Optional Fog Curtain Wand converts fog stream output to a wide fog pattern, plugs into Fog Hose
- Optional Remote Power Cable/Switch operates fogger inside Barrier Isolator or behind closed walls
- Optional Rolling Carry and Storage Case
- 80mm Fog Hose
- Power Supply (120VAC/60Hz or 220VAC/50Hz, 100VAC/50Hz) included along with a power cable for your voltage
- Easy to use fogger requiring a typical 30 seconds to fill water and start fogging
- Instant On fog production and control of fog velocity
- Paperless operation with Instructions and Applications labeled on right side of enclosure
- Other foggers and accessories are shown at right
Smoke Studies in Pharmaceutical ISO Suites, Barrier Isolators, Bio-Safety Cabinets, BSC, Glove Box, Fume Hood, Airflow Hood, Clean Rooms
- Supports ISO 14644-3, Annex B.12 airflow recovery tests
- Supports airflow visualization tests guided by ISO 14644-3, ANNEX B.7
- Supports airflow visualization tests for NSF 49 National Safety Foundation
- Supports USP 797 Insitu Airflow Analysis in ISO suites, sterile rooms and barrier isolators
- Supports SEMI Standards Clean Room Guidelines
- Airflow balancing
- Leak detection in ducts
- Laminar flow tests
- Wet bench exhaust optimization
- Personal safety exhaust verification
- Chemical process equipment ventilation tests
- Pressure balancing between rooms and spaces
- Visualization of airflow patterns and turbulence
Specifications, SMST-12 and AFM40 Cleanroom Fogger
| Metric | SMST-12 Cleanroom Fogger | AFM40 / CRF6 Cleanroom Fogger |
| FOG Duration | about 40-45 minutes | about 40 minutes |
| FOG Volume Output | ≈ 0.5 cubic meters / minute, Velocity control | ≈ 2.0 cubic meters per minute, adjustable fog volume and adjustable flow rate |
| Total FOG Volume | ≈ 22.5 M³, pure fog, during 45 minute cycle | ≈ 80 M³, pure fog, during 40 minute cycle |
| Fog Density (ml/minute) supports visible fog distance | ≈ 76 ml water consumed / Min., converted to 8-10 micron fog droplets | ≈ 225 ml water consumed / Min., converted to 8-10 micron fog droplets |
| Visible Fog Distance | ≈ 6-7 feet visible airflow distance | ≈ 13-15 feet visible airflow distance |
| FOG Type | Ultrasonic Fog using DI water, sterile water WFI water | Ultrasonic Fog using DI water, sterile water WFI water |
| Class of Clean Room Use | Class 10 to 10,000 | Class 1 to 10,000 |
| Compatible Guidelines | USP 797 Insitu Airflow Analysis, ISO 14644-3 Annex B7, Federal Standards 209E in Semiconductor Clean rooms | USP 797 Insitu Airflow Analysis, ISO 14644-3 Annex B7, Federal Standards 209E in Semiconductor Clean rooms |
| Type of Room | Fume hoods, airflow hoods, small glove boxes | Clean Rooms, Sterile Rooms, ISO Suites, Medical Rooms |
| Water volume | 4.5 liters | 13.5 liters |
| Usable Water Volume | 3.42 Liters | 7.5 Liters |
| Method of Operation | Push Button Control, optional Wireless Control | Touchpad Control or optional Wireless Remote Control |
| Method of Movement | Hand Carry Enclosure | Hand Carry Enclosure |
| Liquid Weight | 4.5 L Kg Water, 9.9 lbs | 13.5 L Water, 29.0 lbs |
| Standard Power Requirements | 110 VAC, 50/60 Hz, 10A | 110VAC, 50/60 Hz, 10A |
| Optional Power | 220VAC, 50/60 Hz, 15A; 100VAC 50HZ, 15A | 220 VAC, 50/60 Hz, 10A; 100VAC 50HZ, 10A |
| Dimensions, Inches | 12″ H x 15″ W x 11″ L | 11.5″ H x 12.5″ W x 23.5″ L |
| Empty Fogger Weight | 12.5 lb. | 45 lbs |
INFORMATION
The Clean Room Fogger is used in smoke studies and often called a smoke generator. Although often referred to as a smoke generator, the output is a pure fog and does not require any cleanup after use. Operating instructions are noted on the right panel of enclosure.
Theory of Operation: Ultrasonic cavitation using DI water or Pharmaceutical WFI Water. Use of any other liquids or chemicals will void the warranty.
The transducer life is up to 3000 hours depending on liquids used. the ultrasonic device is protected from overheating by using a water level interlock to shut power off to the ultrasonic transducer in a low water condition. The water level sensor will interrupt the input voltage to the transducer module, should the water level drop to a low level. This ensures long life and reliability of the transducer.
Notes:
- The clean room fog generated by this device contains microscopic droplets of DI water. AVOID USING IN IMMEDIATE VICINITY OF ELECTRICAL APPLIANCES, WATER SENSITIVE PRODUCTS AND EQUIPMENT.
- After a smoke study is completed, drain all the water using the Drain Plug of SMST-12. Optional Air Drier is provided to speed up the evaporation of all water in the water cavity, after a smoke study is completed.
- It is important to evaporate all water in the water cavity so as to prevent algae from growing in the water cavity when water is left in the cavity.
- The clean room fogger is intended to be used on a flat surface, on its feet. Tipping the fogger with water in the reservoir will damage the fogger. DO NOT OVERFILL OR TIP THE FOGGER.
Portable Fogger, SMST-12 Cleanroom Fogger
The SMST-12 provides portability and can be carried using the edge grips on top of the fogger on each side of the fogger. While carrying the fogger in this manner, it is suggested to empty the water out of the cavity before carrying point to point in the lab or smoke study area. Should you need to move the fogger with water in the water cavity, mover the fogger with slow movements, so that water does not splash inside the fogger.
What Does My Smoke Study Require to Visualize Airflow Turbulence?
UltraPure LN2 Cleanroom Fogger, AP35 Fogger @ 5.5 cubic meters fog/minute to provide a very desne ultrapure fog with 15-18 feet visible fog, LN2 + DiH2O or WFI Water, 45 minutes operation, adjustable fog volume and adjustable airflow with touch pad control and wireless remote control. We also have an AP50, AP100 and AP150 LN2 Ultrapure Foggers for higher fog volumes.
* Use Hand Gloves and Face Shield when filling LN2 Use DI Water, Sterile Water or WFI Water |
Clean Room Fogger, SMST-12, 0.5 cubic meters fog/minute at 76 ml fog density with 6-7 feet visible fog, Di Water or WFI Water, 40-45 minutes typical operation, refill and restart.
AFM-40 Fogger, 2.0 cubic meters fog/minute at 225 ml fog density with 12-15 feet visible fog, Di Water or WFI Water, 45 minutes operation, refill and restart, adjustable fog volume and adjustable airflow with touch pad control and wireless remote control.
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Ultrapure, Ultrasonic and CO2 Fogger Discussion
The three types of foggers manufactured for use in the semiconductor and pharmaceutical industry are described below.
Ultrapure LN2 Fogger:
This type of smoke generator or clean room fogger provides the highest volume, density and purity of fog. Fog purity is created by bringing the water to a high temperature to create a water vapor, while simultaneously using gravity to remove any residual mass from the vapor. This process removes any bacterial agents and residual particulate matter from the vapor. The pure water vapor is then combined with a nitrogen vapor which is created from LN2 sitting at room temperature in the LN2 Dewar. The water vapor bonds with nitrogen vapor, creating a nominal 2-3 um fog droplet, at a very high quantity of fog droplets.. The volume of water and nitrogen vapor converted to a visible fog produces a very dense fog stream which exits the ultrapure fogger at about 76 degrees F into the airflow. Almost at room temperature. The fog is ultrapure leaving minimal, if any, trace particles behind. It evaporates to its gaseous hydrogen, oxygen and nitrogen components, which are natural to the Cleanroom environment. The high density of the fog increases the duration and travel distance of the fog. This fogger can be used in a Class 1 – 10,000 cleanroom environments of pharmaceutical and semiconductor facilities; such as sterile rooms, hospital rooms, medical rooms and cleanrooms.
Water-based, Ultrasonic Fogger
This type of fogger has less fog density (less capability to visualize airflow) than the Ultrapure LN2 Fogger described above, but more density than the CO2 fogger described below. The water fogger uses ultrasonic piezos to produce 8-10 micron sized water droplets. When using DI Water, WFI Water or Sterile Water, the water purity is more than sufficient to produce a pure fog for use in ISO Suites, Barrier Isolators, etc. However, Cleanroom Engineers who manage facilities operating at Class 1 to Class 10 performance may desire to use an ultrapure fogger. Although some DI Water foggers are described as ultrapure, unless the DI water is vaporized to remove bacterial agents and residual particulate matter, the fog is not ultrapure. The temperature output is typically less than the surrounding room temperature, thus a fog generated from the atomized water droplets will sink momentarily in a typical 65 degree room temperature.
CO2 Fogger, CO2 Ice and DI Water:
This type of smoke generator, CO2 Fogger, is designed for low volume, non-process critical applications such as bench airflow testing. The fog is created using CO2 ice as the fogging agent, combined with DI Water or WFI water. The fog is generated by evaporating CO2 ice with warm water and is ideal to visualize airflow and turbulence for short periods of time. The fog starts out with a large volume of fog at perhaps 10cfm, but as the CO2 ice evaporates, the fog volume then begins to decrease until no CO2 ice remains. The advantage of a CO2 fogger is the high initial density, making it useful for video applications; and the CO2 fogger is portable as it can be taken into a clean area with no power cords required during the fog process. The output starts at about 9-10cfm and slowly decreases to 0 CFM over a period of 8 – 12 minutes, depending on how much CO2 ice volume is placed in the warm water. There are very few CO2 foggers in use in today’s pharmaceutical smoke studies
Smoke Sticks and Glycol (glycerine) Foggers
Smoke Sticks are used in some Pharmaceutical Clean Rooms around the world. Below is a discussion on the use of smoke sticks used to visualize airflow and turbulence?
A smoke stick is often used visualize airflow turbulence, but smoke sticks are filled with particulates and chemicals. A true smoke is created using chemical reactions; thus the smoke is SPUTTERING (sputter) or popping out of the smoke stick in a non-consistent pattern with velocity, but little volume. It is a particle based smoke, compared to a visible, pure water based fog; thus smoke sticks are a contaminating smoke. The smoke stick generates an inconsistent flow or pattern of smoke, but it is low cost, which is why some managers allow use of smoke sticks in their aiflow visualization studies and smoke studies.
When comparing a smoke stick to a water based, Cleanroom Fogger or an UltraPure LN2 cleanroom fogger, a smoke stick is low volume inconsistent, contaminating fog volume,; while the ultrasonic cleanroom fogger and LN2 ultrapure fogger provide a controlled, pure or ultrapure visual fog. No particulate contamination, no chemical contamination. Water based foggers produce a controlled volume of fog at a controlled velocity, which provides consistent visualization of airflow patterns and turbulence. The Smoke Stick has to be waved around to see what kind of airflow pattern there is, while a Di Water fogger is simply placed in position and produces a flow of fog that can be directed 360 degrees to easily describe the airflow patterns and turbulence. In addition, tubes are now available to create “fog curtains”, or a wall of fog, which smoke sticks can’t produce.
Glycol Foggers
A glycol fogger uses a glycerine liquid combined with a pure water. Glycerine has a long strand, glycol molecule. This combination produces excellent visible fog; however the long strand glycol molecules degrade HEPA filters by clogging the HEPA filtration material, which decreases airflow efficiency over time. An glycerine odor builds up eventually in the HEPA filter, when using glycol fog. Glycol fog would be considered a particulate based fog, as it leaves a trace film on cleanroom surfaces, which need to be wiped down after a smoke study. Additional labor and manpower is required when using a glycol fog in a smoke study. In a pharmaceutical process, how does a technician clean 100% of the glycol residue from the pharma process, since there is contact with the walls and surfaces, which glycol has contacted?
A water based, cleanroom fogger produces a water (H2O) droplet that evaporates into hydrogen and oxygen, the air we breathe. So using a water based fogger or ultrapure fogger, no surface cleanup is required at all. No smoke study delays. The fog is controlled in volume and velocity to visualize the airflow patterns, uniformity and turbulence. These are equipment, quality and application concerns to consider when the need for airflow visualization is considered.
Portable Cleanroom Fogger in Smoke Studies from Applied Metrology LLC.