Document DG4jR2Nmq70pzKZyD7VR7eeEd
PLAINTIFF'S EXHIBIT H&G-53
INDUSTRIAL VENTILATION
21st Edition
A Manual of Recommended Practice
1992
Sales American Conference of Governmental Industrial Hygienists
6500 Glenway Avenue, Bldg. D-7 Cincinnati, Ohio 45211 USA
HG-000056
-5/
#/ JL
A
INCLOSING HCCC
5a' \J
\ -.CPPZP -t-----i-- :-cco
\
ENCLOSE
iCRPES
^
E'lC`,CSE 0?SRA7;.;n a3 MUCr1 a$ =S--SJ
SOURCS. T-Z LESS AIR REQUIRED FOR CCr.TRCL
VtCRS DOMPlETELY ENCLOSED ~PZ
'/ ' <
/L r's
i ASUDT PROCESS
COOO
SAO
DIRECTION OF AIR FLOW
.OCATE THE hOOO SO the contaminant is REMOVED AWAT FROM THE BREATHING DONE OF TViE OPERATOR.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
ENCLOSURE AND OPERATOR/ EQUIPMENT INTERFACE
DATE 1-88
FIGURE
3-3
HG-000057
[' n r- r ->
^ ^ J U u' o
c.xnausi system Design Procedure
5-49
PREFERRED
ACCEPTABLE ELBOW RADIUS
a-
AVOID
// /
! !--
PREFERRED ASPECT RATIO (jj)
;~T --
AVOID
*r ^ u '. ^.
'ecessz"y, jse v v.:r :e vanes. Consult mra. t :.j
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
PRINCIPLE:5 OF DUCT DESIGN ELBO WS
*
DATE
FIGURE
0-27
HG-000058
>ou
Industrial Ventilation
PREFERRED
L
.. - \
\
PREFERRED
PREFERRED
/' / ACCEPTABLE
AVOID it
AVOID
PREFERRED
ACCEPTABLE
AVOID v
BRANCH ENTRY
zmcnc'-es s~Ovjic emer ci grccjc! expansions ana a* an cnqie
5S :ess (preferred) to 45' if necessary. Expansion shornd
:e '5' ~cximijrr.. See Fie. 5--~ *'c-r Loss Factor.
A. V
' ` = VinifT.-jm I'cnsoort veiodty
PREFERRED 1 "
sec:i"
AVOID
PROPER DUCT SIZE S::e me auc: 10 maint:in ihe selected cr richer
^ecsoert ve.ocitv.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
PRINCIPLES OF DUCT DESIGN 'BRANCH ENTRY
DATE 1-88
FIGURE
5-C8
HG-000059
i \ ` i i . . i ^ r"} U U 'J U J d
HG-000060
r . t- U U b b xj
-'OX
IIIUIOU 141 TCIUUUIIUU
DUCT ENLARGEMENTS
/ ------ '
----------- - .
PREFERRED DUCT CONTRACTIONS
i;
* ' 1 -- \
,/
AVOID *
! .. ~J
i * \ ; /;
' PREFERRED
STACKHEAD
>s. Cw.-
_Go
>
n -------
j
iIiII vIs
It 1.
100 1______
>-- -
/ _
PREFERRED
Deflects z.r -jp-.vcr-z
AVOID WEATHER CAP
lC-c: <e!CC!iv contours
Jicmeters
NOT RECOMMENDED!
Defies is c r cownwora
AVOID
See r'c. 5-5: for weather crotecncn
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
PRINCIPLES OF DUCT DESIGN
TE 1-8Q
4
R'gure
________
5-3(9
HG-000061
ur>. ur:.
txnausi aysTem Design Procedure
5-53
1
l1
t
A- \
s
V
.r -IVr.*.<
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
STACKHEAD DESIGSS
1-88
FIGURE
HG-000062
5-31
r- r ' r- S U 'J UOJ.
5-54
Industrial Ventilation
High discharge stack relative to building height, air inlet on roof.
This applies only to the simDie case of a low building without surrounding obstructions cn reasonably level terain.
Note: Low pressure on the lee cf a'building may cause return of contaminants into the building through openings.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
STACK HEIGHT
1-88
FIGURE
o- 32
HG-000063
rfU
VJC7 VEJDCI7Y --
Local txnaust Mooes
3-3
.CC Tv
SLOT VELOCITY --
SOURCE
capture velcc:ty-a:r velocity at any point in front of the hood or at the hood OPENING NECESSARY TO OVERCOME OPPOSING AIR CURRENTS AND TO :-s CAPTURE THE CONTAMINATED AIR AT THAT POINT 3Y CAUSING IT TO FLOW INTO THE HOOD.
FACE VELOCITY- AIR VELOCITY AT THE HOOD OPENING.
SLOT /E_CC:7Y-
AIR VELOCITY '-ROUGH 'HE OPENINGS IN A SLOT-TYPE HOOD. IT IS USED FFHMARILY AS A MEANS OF OBTAINING UNIFORM AIR DISTRIBUTION ACROSS THE FACE OF THE HOOD.
PLENUM VELOCITY-AIR VELOCITY IN THE PLENUM. FOR GOOD AIR DISTRIBUTION WITH SLOT-TYPES CF HOODS. THE MAXIMUM PLENUM VELOCITY SHOULD BE 1/2 OF THE SLOT VELOCITY OR LESS.
DUCT VELOCITY-
AIR VELOCITY THROUGH THE DUCT CROSS SECTION. WHEN SOLIO MATERIAL IS PRESENT IN THE AIR STREAM, THE DUCT VELOCITY MUST BE EQUAL TO OR GREATER THAN THE MINIMUM AIR VELOCITY REQUIRED TO MOVE THE PARTICLES IN T-E AIR STREAM.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
DATE
HOOD NOMENCLATURE LOCAL EXHAUST
4-91
FIGURE
3-1
HG-000064
nr
L U . i i... 13 ,)
Movements of the operator.
Room air currents (w. hich are usually taken at 50 fpm minimum and may be much higher).
Rapid air movement caused by spot cooling and heating equipment.
The shape of the hood, ns size, location, and rate of air flow are important design considerations.
3.4.1 Capture Velocity: The minimum hood-induced air velocity necessary to capture and convey the contaminant into the hood is referred to as capture velocity. This velocity will be a result of the hood air flow rate and hood configura tion.
Exceptionally high air flow hoods (example, large foundry side-draft shakeout hoods) may require less air flow than would be indicated by the capture velocity values recom mended for small hoods. This phenomenon may be ascribed to:
The presence of a large air mass moving into the hood. The fact that the contaminant is under the influence of the
hood for a much longer time than is the case w ith small hoods. The fact that the large air flow r3te affords considerable dilution as described above.
Table 3-1 offers capture velocity data. Additional informa tion is found in Chapter 10.
3.4.2 Hood Flow Rate Determination: Within the bounds of flanges, baffles, adjacent walls, etc., air will move into an opening under suction from all directions. For an enclosure, the capture velocity at the enclosed openingts) will be the exhaust flow rate divided by the opening area. The capture velocity at a given point in front of the exterior hood will be established by the hood air flow through the geometric sur face which contains the point.
As an example, for a theoretical unbounded point suction
SURFACE OF SPHERE
FIGURE 3-4 POINT SUCTION SOURCE
i source, the point in question would be on the surface of a sphere whose center is the suction point (Figure 3-4).
The surface area of a sphere is 4-irX2. Using V = Q/A (Equation 1.3). the velocity at point X on the sphere's surface can be given by
Q = V (4itXz) = 12.57VX2
(3.11
where:
Q = air flow into suction point, cfm
V = velocity at distance X. fpm
A = 4-ffX2 = area of sphere, ft2
*
X = radius of sphere, ft
Similarly, if an unbounded line source were considered, the surface would be that of a cylinder and the flow rate (neglect ing end effects) would be
Q = V(2irXl) = 6.28VXL
(3.2]
where:
L = length.of line source, ft
Equations 3.-1 and 3.2 illustrate, on a theoretical basis, the
TABLE 3-1. Range of Capture Velocities**J_____________________________________________________________________
Condition of Dispersion of ContaminantExample
Capture _____________________________________ Velocity, fpm
Released with practically no velocity into quiet air. Released at low velocity into moderately still air.
Active generation into zone of rapid air motion.
Released at high initial velocity into zone at very rapid air motion.
Evaporation trom tanks: degreasing, etc. Spray booths: intermittent container filling: low speed conveyor transters: welding: plating: pickling. Spray painting in shallow booths: barrel filling; conveyor loading; crushers. Grinding: abrasive blasting; tumbling
50-100 100-200
200-500
500-2000
In eacn category aoove. a range ol capture velocity is snown. The proper choice of values depends on several factors:
Lower End of Range
.-
Upper End of Range
1. Room air currents minimal or favorable to capture.
. 1. Disturbing room air currents.
2. Contaminants of low toxiaty or o( nuisance value only.
2. Contaminants of high toxigity.
3. Intermittent, low production.
3. High production, heavy use.
4 Large hood-large air mass in motion.
4. Small hood-locat control only.
HG-000065
C' ' LU
relationship between distance, flow and capture velocity and
can be used for gross estimation purposes. In actual practice.
however, suction sources arc not points or lines, but rather
have physical dimensions which cause the flow surface to
deviate from the standard geometric shape. Velocity con
tours have been determined experimentally. Row,J-3' for
round hoods, and rectangular hoods which are essentially
square, can be approximated by
Q = V(10X2 - A)
~ (3.3J
where:
Q = air flow, cfm
V = centerline velocity at X distance from hood, fpm
X = distance outward along axis in ft. (NOTE: equation is accurate only for limited distance of X. where X is within l .5 Dj
A =* area of hood opening. ft;
D = diameter of round hoods or side of essentially square hoods, ft
Where distances of X are greater than 1.5 D. the flow rate increases less rapidly with distance than Equation 5.5 indi cates.'3 ~'3 51
It can be seen from Equation 5 3 that velocity decreases inverselv with the square of the distance from the hood (see
LOCATION
C:SC'Jla= :=\ opening VE^CC
- ", ;r
Figure 3-5.)
Figures 3-6 and 3-7 show flow contours and streamlines for plane and flanged circular hood openings. Flow contours are lines of equal velocity in front of a hood. Similarly, streamlines are lines perpendicular to velocity contours. (The tangent to a streamline at any point indicates the direc tion of air flow at that point, i
Row capture velocity equations for various hood config urations are provided in Figures 3-8. 3-9 and 3-10.
3.4.3 Effects of Flanges and Baffies: A flange is a surface at and parallel to the hood face which provides a barrier to unwanted air flow from behind the hood. A baffle is a surface but which provides a barrier to unwanted air flow from the front or sides of the hood.
If the suction source were located on a plane, the flow area would be reduced ('/: in both cases), thereby decreasing the flow rate required to achieve the same velocity. A flange around a hood opening has the same effect of decreasing the required flow rate to achieve a given capture velocity. In practice, flanging can decrease flow rate (or increase velocity) by approximately 25% (see Figures 3-6. 3-7. and 3-11). For most applications the flange width should be equal to the square root of the hood area (\ A ).
Baffies can provide a similar effect. The magnitude of the effort will depend on the; baffle location and size.
Figure 3-11 illustrates several hood types and gives the velocity;flow formulas which apply.
HG-000066
C G 0 C C ?)
Local Exhaust Hoods
3-9
FREELY SUSPENDED HCOi
O = 10X~
A1
LARGE HOOD
ARCE -!OOD. .< SMALL--MEASURE X
:ERPENDiCULAR ~C nGCD FACE NC7 lE-S
HAN 2X FROM -CCD EDGE.
t
SUSPENDED HOODS
(SMALL S:DE-ORaFT HOGOS)
: = REQUIRED EXHAUST air FLOW. C"M. . = DISTANCE FROM HOOD,FACE TO FARTHEST POINT CF CONTAMINANT - = |-:C0D FACE area. FT4. = CA?-_-=E VELOCITY, "m. AT DISTANCE X
GTE - R FLOW RATE MUST 'NCREASE AS 7 r-FF. -.0 3y FLANGING OR S': =LAC:nG CM 2:
xiare z~ distance
rLCOR. e:t -as a
r'O
.AiE,
T.
E SOURCE FROM ThE HOOD.
. ^,1 f*t_ w
5'MINIMUM
0a 0
0
CANOPY HOOD
C = '- a PDV(P = PERIMETER OF TANK. FEET). :.GT =ECCMMENOED IF WORKERS MUST BEND OVER SOURCE. V RANGES -ROM 50 TO SCO FPM DEPENDING CM CRCSSC-aFTS SIDE C-.RTAINS Of! TWO OR THREE SIDES TO IPEATE A SEMI --SOOTH OR BOOTH ARE DESiRASLE.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
FLOW/CAPTURE VELOCITY
1-88
FIGURE
3-8
HG-000067
CG0GG
Local Exhaust Hoods
3-U
BOOTH-TYPE HOODS
1 = av :a=.-ace area. -"':-=-rAzz -i-lZ'-. "m ). saffles are :=TiOMAL -:= a.= oist^sorcn. not =e-:ureq if a water
CT'-cR mFams
DiS R:BL'"'Cn '-"OVIDEO
: .ARIES rRCM A I'lC-ES "0 a NOES. DEdNDING on SIZE IF SOOTH
' .ARIES FROM 6 :'.CHE5 TO '-I :NOE5. CE=NDtNG ON SIZE OF SCCTh.
`0=EA3E ~"E .\'_v.rE= Tr 7.v7h S IE OF SOOTH
wade
sooth
or
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
FLOW/CAPTURE VELOCITY
1-88
FIGURE
3-10
HG-000068
000067
10-84
Industrial Ventilation
To prevent condensation, insulation, strip heaters' or dilution fitting may be necessary.
Skip hoist hood Q = 250 LW
Skip hoist hood t^ =1.78 VPS + 0.25 VPd
Enclosing hood
Slots
Opening for skip loading
/ N l L-Baffle
Sft/.'
i
Mulleir
J__ L
Q = 150 cfm/ft through all openings but not less than:
Muller diam. feet 4 6 7 8 10
Exhaust, cfm 750 900 . 1050 1200 1575
Minimum duct velocity = 4000 fpm he = 0.25 VPd
Notes: 1. Other types of mixers: enclose as much as possible and provide 150 cfm/ft2 of remaining openings.
2. When flammable solvents are used in mixer, calculate minimum exhaust rate for dilution to 25% of the LEL. See Chapter 2.
3. For air-cooled mullers, see VS--60--02.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
MIXER AND MULLER HOOD
date
U-90
60) figure vs-
-01
HG-000069
C Ci 0 0 G 3
Specific Operations
10-85
Location
Minimum exhaust rate, cfm Muller type
Blow--though Draw-though
No cooling
cooling
cooling
Batch hopper Bond hopper Muller:
4' diameter 6' diameter 7' diameter 8' diameter 10' diameter
Note 1
600 Note 2
750 900 1050
1200
1575
600 600 Note 3
Note 1
600 Note 3
Minimum duel velocity = 4500 fpm
he= 0.25 VP Notes:
1. Batch hopper requires separate exhaust with blow-through cooling. With other fan arrangement (mulier under suction), separate exhaust may not be required. (If skip
hoist is used, see VS --60-01.)
2. Maintain 150 fpm velocity through all openings in mulier hood. Exhaust flow rates shown are the minimum for control.
3. Cooling mullers do not require additional exhaust if maintained in dust-tight condition. Blow--through fan must be off during loading. If mulier is not dust--tight, exhaust as in note 2 plus cooling air flow rate.
4. When flammable solvents are used in mixer, calculate minimum exhaust flow rate for dilution to 25% of the LEL. See Chapter 2.
AMERICAN CONFERENCE OF GOVERNMENTAL
INDUSTRIAL HYGIENISTS
0ATC
AIR-COOLED
MIXER AND4 MULLER
U-90
| figure VS-60-02
HG-000070
r\ r\ r. r t- U J L