Transcript Service seminar March 2002

Particle Measurement
& Validation bv
• Peter van ’t Erve
• Project Manager
• International Service
Erkenningsnummer
3445-00
Particle Measurement
& Validation bv
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Introduction
Basic stuff
HEPA-filtration
Types of cabinets
Maintenance
Criteria
Disinfection
HEPA-filter change
Miscellaneous
Erkenningsnummer
3445-00
Basic stuff
Basically a cabinet consists of :
 The Body
: Stainless Steel
Epoxy coated steel
 Prefilter
: Eff. 80 – 90% acc. EN 779
 HEPA-filters : Eff. 99,99% acc. EN 12469
 Fan
: To create the velocity
 Electronics : To control the velocity and the alarm features
 Accessories : on customer requirement
Basic stuff Pre-filters
 Cheap glassfiber filter-material, to protect the expensive HEPAfilters
 To be changed every year
 Low cost exchange
 Lifetime of a HEPA:
without Prefilter appr. 6 years
with Prefilter : appr. 12 years
Filter classification according EN 779
Filter type
Pre-filters & Fine-filters
Filter class
G1
G2
G3
G4
F5
F6
F7
F8
F9
Am %
>65
65<80
80<90
90
-
-
-
-
-
Em %
-
-
-
-
40<60
60<80
80<90
90<95
95
Basic stuff H.E.P.A. filters
 HEPA = High Efficiency Particulate Air
 ULPA = Ultra Low Particulate Air
The purpose of a HEPA-filter is to catch
small particles.
Construction of a HEPA-filter:
 Filter media (Glass fiber or
similar)
The media is pleated to a
package of a certain size.
The pleated media is glued
together in a frame
HEPA-Filtration: Efficiency
 The efficiency of a HEPA-filter according EN 12469:
99,99% when tested by means of a photometer.
100.000
particles
10 Particles
HEPA-Filtration
Sieve operation of a HEPA
HEPA-Filtration
Interception/impaction
Types of cabinets: General
 Product Protection
 Personal protection
 Product and personal
protection
Types of cabinets: Product protection
 Downflow unit
 Laminar Downflow
 Crossflow
Types of cabinets: Biological safety cabinets
Class II A
Class II A
(Double exhaust)
HEPA-Filter
Pre-filter
Class II B
Types of cabinets: Biological safety cabinets
Flow pattern
30%
Inflow
Recirculation
Pressure plenum
Downflow
Exhaust
70%
Maintenance: General
Check on Pre-filter
Airflow velocity’s
downflow & inflow
Filter efficiency test by means of a photometer
or particle counter
Check on alarmsettings
Maintenance: Control of Pre-filter
 Product Protection
 Personal protection
 Product and personal
protection
When do we need to change
it?
Turn over one edge of the pre-filter,
If the down side is becoming grey,
replace it.
Take care of contaminated areas !!
Maintenance: Control of air flow and velocity
Test
Retention at front
aperture
Leaktightness
of carcass
Filters
Product protection
Cross
contamination
Routine
maintenance
testing
Check that
manufacturer’s
specification is met;
Not applicable
Filter efficiency test
with the help of a test
aërosol
Check that
manufacturer’s
specification is met;
Check that
manufacturer’s
specification is met;
Measuring air velocity
(Annex G en H)
Measuring air velocity
(Annex G en H)
Measuring air velocity
(Annex G en H)
Check airflow patterns
Check airflow patterns
Check airflow patterns
(Annex D)
Maintenance: Airflow measurements (EN 12469)
Airflow velocity measurements
Downflow
Measurements have to be taken at
- 8 positions minimum,
- 50 to 100 mm above the top edge of the front aperture.
1/4 d
1/4 d
1/8 l
Criteria:
1/8 l
3/8 l
- All values have to be >0,25 and < 0,50m/s;
- According manufacturer’s specifications;
- No individual measurement should deviate more than 20% from the mean.
3/8 l
Maintenance: Airflow measurements (EN 12469)
Airflow velocity measurements
Inflow
According Annex G you have to measure the velocity in the exhaust duct and calculate the
volumetric rate of discharged exhaust air. With this air volume you can calculate the mean
inflow velocity.
In practice it is much more easier to measure the inflow velocity in the front aperture.
Window
Working
space
according manufacturer’s specifications.
a
b
c
Side view
2
3
a
b
c
H
L
4/8 L
Front view
1/8 L
Criteria:
Mean inflow velocity > 0,40 m/s and,
1
7/8 L
Maintenance: Airflow measurements (EN 12469)
Flow pattern
Tested using smoke
Inflow:
The direction of the inflow should be inward over the whole area of the front aperture.
Downflow:
The direction of the flow should be downwards without turbulence as a result of options
or other obstructions in the working area.
Maintenance: Control of HEPA filter efficiency
Procedure:
Option 1.
Filtertest with a Particle Counter and a test aërosol.
Option 2.
Efficiency test with a Photometer and a test aerosol.
Criteria:
Tested with a Photometer a local penetration should be not more than 0,01%.
Related Standards:
• IES-RP-CC006.2
• ISO/CD 14644-3
• EUROVENT 4/8
Maintenance: Control of HEPA filter efficiency
Downflow /
Crossflow unit
Generating the test aerosol
(DOP, Emery 3004 , DEHS)
Referential measurement
(80-120 µgr / L)
100% measurement
Scanning probe
Photometer
Maintenance: Control of HEPA filter efficiency
_
+
Generating the test aerosol
100%
+
(DOP, Emery 3004 , DEHS)
_
+
+
_
+
+
+
+
100% measurement
+
(80-120 µgr / L)
Probe
Scanningprobe
_
_
Photometer
_
_
Maintenance: Control of HEPA filter efficiency
Generating the test aerosol
(DOP, Emery 3004 , DEHS)
100% measurement
(80-120 µgr / L)
Scanningprobe
Photometer
Probe
100%
Maintenance: Alarm Settings (EN 12469)
Inflow
Downflow
 High Alarm
 Create a high alarm by increasing the
voltage of the fan and check whether
there is a high alarm.
 Low Alarm
 Create a low alarm by de-creasing the
voltage of the fan and check whether
there is a high alarm.
 High Alarm
 Create a high alarm by increasing the
voltage of the fan and check whether
there is a high alarm.
 Low Alarm
 Create a low alarm by de-creasing the
voltage of the fan and check whether
there is a high alarm.
Window Alarm (If applicable)
Check whether there is an alarm if the window is not in a calibrated position.
Other alarmpoints
 Check all other alarmpoints
Maintenance: Setting the alarms
• Adjust velocity
• Determine High alarm
(Vav + 20%)
• Determine Low alarm
(Vav - 20%)
• Make your alarm
window as big as possible
• Adjust alarmwindow to
calculated alarmsettings
• First High alarm
• Then Low alarm
High alarm
Vav
Low alarm
Maintenance: Testpoints CA(B) / x and EF(B) / x cabinets
A: Aerosol supply
B: 100% measuring point (and test point for overall efficiency test
1st HEPA-filters on a CB and EFB)
This point might also be on top of the cabinet for a CA(B)
C: Scanning downflow HEPA-filter
D: Scanning exhaust HEPA-filter (overall efficiency test on a CA(B)
Ducting: Ways of ducting
There are three ways to connect a safety cabinet to a duct!
1. Direct connection!
2. Direct connection with a by-pass!
3. Connection via a thimble!
Ducting: Direct connection
Externalfan
Anti Blow Back Valve
Airsupply
•
•
•
•
Both cabinet and the external ventilator have to be
switched on at the same time, this is done by a
potential free contact (optional accessory) coming
from the cabinet!
The anti blow-back-valve assures that no
contaminated air can travel back into the cabinet!
The room pressure will fluctuate depending if the
cabinet is switched on or off. However it is possible
to have the air inflow adjusted to the amount of air
that is extracted from the room!
Advantage: Higher level of safety!
Ducting: Bypass connection
Externalfan
Anti Blow Back Valve
By-pass valve
Airsupply
•
•
•
•
•
•
The external ventilator works 24hrs a day!
When the cabinet is switched on the by-pass
valve in the duct will open in order to extract
the exhausted air from the cabinet.
When the cabinet is switched off the valve will
close and will extract the same amount of air
from the room!
The valve is also controlled by a potential free
contact coming from the cabinet.
The anti blow-back-valve assures that no
contaminated air can travel back into the
cabinet!
Advantage: Higher level of safety and the room
pressure will be constant at all time!
Ducting: Via a Thimble
Externalfan
Airsupply
Effects on the roompressure:
•
When the cabinet is switched on the
exhausted air will be extracted from the
cabinet!
•
When the cabinet is switched off the
exhausted air will be extracted from the
room!
•
Advantage: No adjustments have to be
made to the cabinet and the pressure in
the room will be constant!
What will be the effect on the alarm settings if the cabinet is
connected on an exhaust duct work?
There are three possibilities:
 There is no extra fan in the exhaust system.
Adjusting the alarms can be done by increasing or decreasing the downflow
and inflow air velocity by means of the fan of the cabinet.
 There is an extra fan in the exhaust system, but there is no
link between the status (Day- or Stand-by position) of the cabinet
and extra exhaust fan.
 There is an extra fan in the exhaust system, with a link
between the status (Day- or Stand-by position) of the cabinet and
extra exhaust fan.
Disinfection
 Why desinfection:
- Microbiological Safety Cabinet is a Biohazard.
HEPA-filtered air
- All parts in the cabinet are a possible risk for
both personnel and environment when opened.
HEPA-filtered air mixed with
product
Air mixed with fresh air and
product
Contaminated air
 When desinfection:
- If repair needs to be done inside the cabinet.
 With what can we desinfect a cabinet
- That depends on the product which was handled in the cabinet,
responsible for desinfection is the head of the laboratory.
Disinfection
Using Formalin
 Clean Air techniek offers a so called FAS 2000 which
is using Formalin for desinfection and Ammonia to
neutralize the Formalin afterwards.
FAS 2000
HEPA-filtered air
HEPA-filtered air mixed
with product
Air mixed with fresh air and
product
Contaminated air
Disinfection
Using Formalin
 Depending on the size (volume) of the cabinet,
Formalin is put in the can with the red cap and
Ammonia is put in the can with the blue cap.
FAS 2000
Disinfection
Using Formalin
 In order to prevent Formaldehyde of getting into the
laboratory, the cabinet has to be sealed off.
 You can do this by sealing the cabinet with a plastic bag.
Make sure that the bag is sealed to the floor.
HEPA-filter change
1st HEPA
 First HEPA-filter on a Class IIB cabinet:
HEPA-filter change
1st HEPA
 Take of the pressurebar.
(On older models you have to cut the silicon along the outer edge of the filter.)
HEPA-filter change
1st HEPA
 Seal the opening of the HEPA-filter in order
to prevent parts to come out of the HEPA-filter
HEPA-filter change
1st HEPA
 Replace the HEPA by a new one and put the pressure
bar back in it’s place.
HEPA-filter change
Downflow HEPA
 Take of the backpanel
Disconnect the fan and
take it out
HEPA-filter change
Downflow HEPA
 Unloosen the pressure bars of the downflow plenum and the exhaust HEPA and take them out.
 Lift the pressure plenum and take it out.
 Take out the HEPA-filter.
Pressure bars
Plenum
HEPA-filter
HEPA-filter change
Downflow HEPA
 Put in a new HEPA-filter with the seal downwards and put everything back in it’s place.
HEPA-filter change
Exhaust HEPA
 Lift the exhaustduct
 Unloosen the
pressurebars
and take them out
 Lift the pressure plenum
and take it out
 Take out the HEPA-filter
 Put in a new HEPA-filter with an
extra seal on one end.
 Put everything back in it’s place
Criteria
Criteria
Cabinet type EF / x (EN 12469)
- HEPA-filter efficiency downflow > 99,99%
- HEPA-filter efficiency exhaust > 99,99%
- Vaverage downflow velocity: 0,35 m/s.
-Alarm for downflow velocity: Vaverage +/- 20% as where all individual
measurements should be
> 0,25m/s and < 0,50m/s.
- Vaverage inflow velocity : > 0,30 m/s at the top of the working opening.
- Alarm for inflow velocity: < 0,28 m/s at the top of the working opening.
Criteria
Cabinet type EFB/ x (EN 12469)
- HEPA-filter efficiency downflow > 99,99%
- HEPA-filter efficiency exhaust > 99,99%
- HEPA-filter efficiency 1st HEPA > 99,99%
- Vaverage downflow velocity: 0,35 m/s.
-Alarm for downflow velocity: Vaverage +/- 20% as where all
individual
measurements should be
> 0,25m/s and > 0,50m/s.
- Vaverage inflow velocity : > 0,30 m/s at the top of the working opening.
- Alarm for inflow velocity: < 0,28 m/s at the top of the working opening.
Criteria
CLF x and DLF x
 Downflow unit
- According Federal Standard 209B
- HEPA-filter efficiency > 99,99%
- Vaverage downflow velocity: 0,35 m/s.
- Vaverage horizontal velocity: 0,45 m/s.
- Alarm : Vaverage - 20% and Vaverage +20% if applicable.
 Crossflow
Criteria
Standards
BS 5726
HEPA-filter efficiency
Downflow HEPA
HEPA-filter efficiency
Exhaust HEPA
HEPA-filter efficiency
First HEPA
Downflow velocity
Inflow velocity
DIN 12950
DIN 12980
EN 12469
> 99,997%
> 99,997%
> 99,997%
> 99,99%
> 99,997%
> 99,997%
> 99,997%
> 99,99%
Vaverage should be defined by the Vaverage= 0,40m/s
manufacturer and should be > 0,25 - Additionally no individual
< 0,50 m/s.
measurement should differ more
Additionally no individual
than 20% of Vaverage as where all
measurement should differ more
individual measurements should be
than 20% of Vaverage and be > 0,25 - > 0,32m/s and < 0,48 m/s.
< 0,50 m/s.
> 99,99%
> 99,99%
Vaverage should be defined by the Vaverage should be defined by the
manufacturer and should be > 0,32 - manufacturer and should be > 0,25 < 0,48 m/s.
< 0,50 m/s.
Additionally no individual
Additionally no individual
measurement should differ more
measurement should differ more
than 20% of Vaverage and be > 0,32 - than 20% of Vaverage and be > 0,25 < 0,48 m/s.
< 0,50 m/s.
DLF / BSS x : Vaverage = 0,35 m/s CA / x : Vaverage =0,40 m/s
DLF / REC x : Vaverage = 0,35 m/s
CB / x : Vaverage =0,35 m/s.
EF / x : Vaverage =0,38 m/s
EFB / x : Vaverage =0,38 m/s
Vaverage should be > 0,70 m/s.
Vaverage should be > 0,40 m/s.
Vaverage should be > 0,40 m/s.
Vaverage should be > 0,40 m/s.
DLF / BSS x :
Vaverage on top of working opening
should be > 0,22m/s.
Alarmsituation : Vaverage < 0,19m/s.
DLF / REC x :
Vaverage on top of working opening
should be > 0,22m/s.
Alarmsituation : Vaverage < 0,19m/s.
CA / x :
Vaverage on top of working opening
should be > 0,28m/s.
Alarmsituation : Vaverage < 0,26m/s.
CB / x :
Vaverage on top of working opening
should be > 0,28m/s.
Alarmsituation : Vaverage < 0,26m/s.
EF / x :
Vaverage on top of working opening
should be > 0,28m/s.
Alarmsituation : Vaverage < 0,26m/s.
EFB / x :
Vaverage on top of working opening
should be > 0,28m/s.
Alarmsituation : Vaverage < 0,26m/s.
Video
Test equipment
Test equipment
Photometer
LIGHT STOP
CONE OF LIGHT
PHOTOMULTIPLIER
TUBE
LIGHT SOURCE
CONE OF
DARKNESS
3 WAY VALVE
VACUUM
UP
STREAM
FILTER
DOWN
STREAM
Test equipment
Aerosolgenerator, generating a testaerosol DOP, EMERY 3004 or DEHS
ADJUSTING
KNOB
NITROGEN
INLET
PRESSURE
REGULATOR
FILTER
ORIFICE
AND
VALVE
SIGHT
GLASS
ADJUSTING
KNOB
AEROSOL
RESERVOIR
PRESSURE
REGULATOR
HEATER BLOCK
AIR
INLET
2
NOZZLES
FILTER
DRAIN
SIGHT
GLASS
AEROSOL
SOLUTION
5
NOZZLES