Document NEaKjK4XY1KXn3EKk91YExo78
FILE NAME Industrial Hygiene Foundation IHF
DATE 1944 Mar DOC IHF080
DOCUMENT DESCRIPTION Excerpts - Report of Industrial Hygiene made For Manhattan with Cover Letter
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INDUSTRIAL HYGIENE FOUNDATION OF AMERICA
4400 FIFTH AVENUE
PITTSBURGH PA
April 18 1944
Mr. O. H. Cilley Asst Gen. U. S. Asbestos Division
Raybestos Manhattan Inc. Monheim Pa
Mgr
Dear Mr. Cilley
Enclosed is the report giving the results of the Foundation's recent studies at your Manheim operations which are a part of your con-
tinuing dust control program Additional copies of the report are provided for your associates The statement covering the work is enclosed
Please note that the Foundation arranged for examination of dust
|
samples by the electron microscope This because of circumstances involved '
was somewhat taking
After the report has been examined we anticipate that you or
associates may have some questions If so we invite you to correspond Mr. W.C.L. Hemeon direct After the recommendations have been carried
your with
forward we will
expect
to
continue
the
study and we will
appreciate
your
;
advices when the time is opportune
We are enclosing a copy of the Foundation's bulletin on Heasure-
ment of Air Flow in Industrial Ventilation which Mr. Hemeon promised to Mr. Joyce
The excellent assistance and cooperation which was given Mr. Hemeon
was of great assistance in the conduct of this work
Very truly yours
.
3?
we.
JTM ends
7 John F. McMahon
Managing Director
FOR THE CONSERVATION OF EMPLOYEE HEALTH IN INDUSTRY
sch
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
4400 FIFTH AVENUE PITTSBURGH PA
REPORT OF INDUSTRIAL HYGIENE SURVEY
MADE FOR
_. United States Asbestos Division oo
of
ManhattaInn c. Manheim Pennsylvania
March 14,15,16 and 17 1944
FIELD WORK BY
W.C.L.
Ventilation
done
pre
VentilationEngineer
Ventilation Engineer
LABORATORY WORK BY
Francis Francis
Holden R. Holden
Industrial Hygienist
Ph.D .
April 1944
~~
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
MMiisssalosn alon Missalon
Missalon Jola
MANAGING Missalon
MissalonMissalon
YD 27. 27. Oc
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial Ventilation Survey
of the
United States Asbestos Division of Raybestos Inc.
Manheim Pennsylvania
March 14,15,16 and 17 1944
SUMMARY
This is a report of a study undertakon to locate the most impor-
tant sources of dust and to develop additional dust control measures at
the Manheim plant of U. S. Asbestos Division of Raybestos Inc.
Sixteen dust counts were made in various departments These samples
)
indicate that conditions in the Picker House are not satisfactory but
dustiness in the Carding Spinning and Twisting Departments is less than
5 million particles per cubic foot Recommendations are made that can
lead to a reduction of dustiness in the Picker House as well as in the
Carding Department It is believed that while the card room is under
considerable negative pressure the consequent starvation of the exhaust
any equipment is probably not in itself sufficient to account for
a
am
markod
reduction in control of dust
The results of dust counts are given in Table I.
2
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U.S. Asbestos Div of
. Raybestos Inc. Manheim Pa March 14 15 16 17,1944
TABLE I
Dust Counts
Sample
No.
Date
Time
24
3/14/44 50-2 P
27 3/14/44 35-1 P
21
19 ESP
10
3/14/44 16-2 P
3/14/44 3/143//14/44 44
:
53
22 22
P44
3/17/44 50-10 42A
Location and Operation
Picker House
At Pan Crushers to nearly simulate operator's exposure Floor Batching - Exposures of 2 workers outside booth - Finished about
1:42
Operation of Pan Crushers forAmosite-
Time represented complete cycle of operation 1/2 hour daily
Batch feeding vertical opener Ex-
posure of operator within booth
52 minute sample at central point of room for general air near
vertical opener
Particles per cu ft 8.7 million
1.7 million
38.0 million
million
9.9 9.9
million
million
5.6 millio
23
3/14/44 59-3 P
26
3/134/14/44/44
17-3
17-3 :
17-3
27
P
1
3/15/44 54-11
02
3/15/44 15-11
Carding General air walking about various carding machines in Breaker Card Room Besido point of discharge from con-
point
denser to box in Breaker Card Room
At roving end of 4 finish cards 1 2,7,8 General air - Exposure of 2
attendants
Along central aisle at camel
ends of cards
4.0 million
millior
3.3.8 8 millimilolior r millior
4.3 million
4.8 million
_
ESP 11
3/17/44
49-11 :
49-11
:
4949A A
Between finisher cards 15,16,21,22
All windows
of
carding carding
and
spinninsgpinning
room open wide to
simulate
simulate
summer
con-
ditions
millio
2.8 2.8 millio:
3
3/15/44 48-11
Spinning and Winding
At mule spinner while following oper-
ator to simulate his exposure
4.8 millio
At Universal winders 2nd floor ad-
4
3/15/44 10
P 1 joining cards - following operator
3.0 millio
exhaust
;
5
3/15/44 56-1 P
3/15/44 50-2 P
At Foster Winders Average of all
aisle
At Twisters Average of all aisle
3.63.6 millio
4.0 millio
3/15/44 19
P2
At L frames frames on 22nd nd
along aisle
floor .
Averago Averago
3.6 millio
8
3/15/44 45
P2
At
frames
frames
on
1st
along aisle
floor .
AvAveerargeage
millio
2.0 millio
_
Note
All samples with Midget Impinger except those marked ESP Electrostatic
Precipitator)
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
3
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
DUST CONTROL IN THE PICKER HOUSE
Operation of the pan crushers results in excessively high concen-
trations of dust as shown by Sample 24 8.7 million It is recommended
that the system originally designed which contemplated keeping the doors of
the enclosure closed most of the time be supplanted by the following arrange-
ment
Exhaust from each pan crusher hood a sufficient volume of air to
create a velocity of 200 feet per minute through one of the two working
openings whose dimensions should be reduced to 2 feet wide by 2 feet high
it is suggested that inasmuch as the two openings would never be necessary
at any one time doorway covers be provided that are interconnected so that
when one is opened the other will close The covers might be hinged and
their closure motions connected by cable and pulley or they could be slidable
vertically and similarly interconnected In any case a snug fit is unnecessary and should be avoided for ease in manipulation This plan will call for a
total exhaust capacity of 5000 c.f.m. for the four crushers
Batching The dust counts of Samples 27 and 19 indicate that the two workers
stationed outside the booth are not exposed toimportant dust concentrations but that the man who feeds the vertical opener within the booth is exposed
to concentrations of about 10 million particles during the actual batching by the two men outside His average exposure of course is less than this because of the intermittent nature of the operation
4
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17
1944
It is recommended that consideration be given to the erection of a batching bed comprising a long narrow bin located in the position where the pile is now made on the floor This bin would be enclosed and exhausted and have as an important element a side facing the opener that
may be removed or shifted by raising when the batched material is ready for
feeding to the machine Further study will be given to this at the time of the next visit The arrangement is illustrated diagrammatically in Figure 1
Tandem Vertical Opener This unit was not in regular operation at the time of the study
but it was apparent from a brief specially arranged operation that con-
siderable dust leaks from the cast iron cover located adjacent to the con-
denser It should be possible to correct this without the application of
exhaust either by replacing the cover or by providing an adequate gasket
The giant cutter Johnson's grader waste machine and willow were not in operation at the time of our studies
.
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
.
5
Industrial ventilation survey of the U. S. Asbestos Div of
DUST CONTROL IN CARDING
Studies of uncontrolled dust sources around the carding machines
disclosed the following
Feed Rolls
An appreciable amount of dust originates at the feed roll of many
of the finisher cards which can best be observed with an intense light beam
Some machines are equipped with curved trays or baffles under this roll
which are effective in minimizing dust at this point Observations on this
point made on somewhat less than half of the machines are as follows
Card No.
Observation
1 2
5 + 5072 2 2 50722222 50722222 50722222
~
50722222 50722222 50722222 50722222
OK Fair
OK
but needs front to complete enclosure
Dusty
OK
Dusty Dusty
OK
Dusty
OK
OK
OK
It is recommended that such baffles be installed on all finisher
cards not now equipped This point was discussed particularly with the
card room foreman
6
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Manhattan Inc. Manheim Pa March 14,15,16,17 1944
Wiper Roll and Rub Apron
doffer
Another dust source is at the junction of the wiper roll and the
A partial check of machines was made with the conclusion that an
_ appreciable amount of dust occurs at this point in the case of the following | finisher cards
Numbers 3 4 9 10 17 18 23 24 It was noted also that some dust originates from the rub aprons
and since these are adjacent to the wiper rolls it may for purposes of
controble considered the same source of dust
It is recommended for the top set of rolls that a removable cover be provided clear over the upper set of rub aprons thus in effect extend-
ing the present exhausted enclosure and rendering this dust cource subject
to the influence of the present exhaust It may also be advisable to re-
move one stave at the lower end of the existing enclosure immediately over the doffer roll to facilitate air flow through the supplementary enclosure
For the lower rub apron and wiper it is recommended that some
experimental work bedone on a bood as suggested below We illustrate in
Figure 2 an exhaust hood or slot which is designed to be placed immediately
adjacent to the wiper roll at the point where it joins the rub apron In
the design illustrated an attempt has been made to reduce the width of the
hood to the smallest possible dimension in order to avoid interference with proper functioning of the machine In this preliminary design we provide
for
ve
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
7
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
a an air flow of 75 c.f.m. per foot of length
b
a face velocity of 2000 feet per minute to aid in
effecting good distribution along the length of
each slot section and
c
elimination of excessive cross sectional area in
transition section in order to maintain adequate velocities for the transport of material
the
A partial compromise has been incorporated in the design to avoid a too
complicated hood but it is believed that the lower velocities at the largest section of the transition will not seriously interfere with its proper function
Not shown on the diagram are necessary pieces at the ends which
will extend to the side frames and serve to support the unit in position
It would be advisable to have a quickly detachable connection with the
branch duct that will lead to the exhaust main overhead
Reserve Exhaust Capacity The following observations indicate that there is adequate exhaust
capacity for the supplementary exhaust hoods described above
The capacity of the exhaust system indicates an average of 700-800
c.f.m. per cylinder Some individual measurements of air flows in different
branches were made by means of static suction measurements with the
dampers in the position that had been set by the operators of the carding department They indicate what was considered adequate by the operating
personnel as judged visually As may be seen from the results in the follow-
ing table they vary quite widely
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
8
Industrial Ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
Air Flows Through Individual Card Hoods
Unit
Taking Damper Adjustment as Found
'
Static suction
Air Flow
# Finisher # Finisher 2 Breaker 3 Breaker # Finisher 4 Breaker 5 Breaker 5 Finisher 31 Breaker
1.9 1.0 0.6 0.8 0.4 0.2 0.6 1.6 1.4
inches
" " " " 3 ft " 7
920 670 515 590 420 210 510 840 790
c.f.m.
" " " " " =O == "
It is particularly significant that even in the case of 3 Finisher and 4 Breaker no escaping dust could be detected at any point
This indicates that there is considerable reserve capacity
9
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Manhattan Inc. Manheim Pa March 14,15,16,17 1944
AIR EXHAUST AND SUPPLY IN VARIOUS DEPARTMENTS
Picker House
With all doors and windows closed as is the case in winter the Picker House was found to be under a negative pressure of 1/2 water column
While this is likely to starve at least some of the exhaust equipment we
believe the dust sources enumerated above are of much greater importance ' than this factor and should receive prior attention A tabulation of exist-
ing exhaust capacity from this department is given in the table below and
is based principalloyn the measurements made by Mr. Bertelet and Mr. Gilpin
Unit
Exhaust Capacity in Picker House
,
Capacity
Old Shaker Screen
Cotton Machine
Willow and Tandem Vertical Opener New P. & S. Grader through
condenser over shaker screen
New shaker screen through
condenser in card room C.O.B.
15 Pipe to Breaker card system
from pan crushers etc. estimated
2500
2900 6000
c.f.m. C.f.m. c.f.m.
3400 c.f.m.
2900 c.f.m.
2400 c.f.m.
2500 c.f.m.
Total
22600 c.f.m.
Unbalance in Card and Spinning Department
~k
The measurement of air flow from the carding exhaust systems together
with other data obtained from Mr. Bertelet is tabulated below to indicate the
total volume of air exhausted from the room
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
10
Cards 13-24
frames older frames newer
system
system -
estimated
Total .
17,000 13,000
13,000
c.f.m. c.f.m. c.f.m.
58,000 c.f.m.
The available data for the breaker card room are as follows
Right half double fan Left half double fan
From Picker House estimated
6,500 7,900 14,500 2,500
c.f.m. c.f.m. c.f.m. c.f.m.
Net from breaker room
12,000 c.f.m.
Some air is supplied to this floor from the first floor Carrier
system but there is a deficit for the carding and spinning department of
|
about 32,000 c.f.m.
There is however an air supply unit in this department with a
capacitoyf 36,000 c.f.m. which is operating at present as a heater only and requires modification brought out by Mr. Bertelet to permit it to handle
outdoor air directly The necessary changes should be effected The same is true of the breaker room where a unit with a capacity
of 18,000 c.f.m. requires modification to permit it to supply properly
tempered outdoor air to the room
Effect on Dust Control
Pitot tube measurements were made on one of the main pipes with
the windows open and with windows closed In the former case the velocity
was 3100 feet per minute and in the latter case 2970 feet per minute a ratio
of 1.05 indicating a % increase in air flow These measurements are not
considered exact
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
11
The characteristic curve of the fan American Blower Company
steel plate fan 80 at 662 r.p.m. is shown as Figure 3 and as may be
seen from the analysis indicated thereon an increase in air flow of 10 to
15 be may
expected by reducing the resistance by 0.4 inches
One would TN,
hardly expect material difference in the operation of the exhaust system
difference difference
with such a small percentage
with
ee
Dust sample ESP 11
increase in air flow
,,
shows a concentration with
all
windows
wide
open of 2.8 million particles as against concentrations of over 4 million for example sample 1 taken two days earlier If this comparison is to
be considered representative it must be due to the additional general venti-
lation caused by natural air currents through the open windows That is
in warm weather with all windows open a volume of general ventilation in
addition to that caused by operation of the exhaust system will be obtained
and must affect the dust situation favorably This would not however indi-
cate marked improvement in winter by providing just the proper volume of
.
make up air
Such unbalanced conditions are always likely to cause discomfort
because of drafts that occur in the peripheral areas of the room so it
is recommended that correction be made
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
12
TWISTING DEPARTMENT DEPARTMENT
No conclusions were reached with regard to improved dust control
in this department but data on the exhaust capacity and volume of air
supplied by the Carrier system is reported below With the assistance of Mr. Bertelet and Mr. Gilpin wo made 64 readings of linear velocity at the face of the heater whose area is 81 sq.ft. and concluded that under conditions then prevailing the system was delivering 60,000 c.f.m.
A capacity of the various exhaust systems has been estimated by
Mr. Bertelet as follows
Foster Winders East Fan West Fan
Twisting Machines North Fan
South Fan Cop Winders
Total
'
3300 c.f.n.
3330 c.f.m.
11000
11000
5000
c.f.m. c.f.m. c.f.m.
33600 c.f.m.
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Manhattan Inc. Manheim Pa March 14,15,16,17 1944
RECAPITULATION -- AIR EXHAUST AND SUPPLY
Total Exhaust c.f.n.
Potential Supply
Picker House Breaker Card Room
Carding and Spinning Room
22,600 22,600 12,000 58,000
Twisting Department
.
33,600 33,600
17,800 36,000
26,400
33,600 33,600
Existing Carrier Unit
modified
Existing Carrier Unit
{
modifica
Overflow from Twisting
{
Department
Required portion from avail
J
ablemain
supply of 60,000 Carrier system
from
It appears from the tabulation above that there are available means
for supplying all requirements except that for the Picker House It is
believed that this may be cared for by air cleaning units to permit recircu-
lation from some of the systems handling small amounts of dust See following section
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
14
AIR FILTRATION
An effective dust collector which will produce clean air 1.8 one
with a dust content of less than 1/4 million particles per cubic foot would
have valuable applications It could serve to reduce the unbalance between
air exhaust and air supply by drawing air from the dust house for recircula-
tion and also would permit direct recirculation from some of the exhaust sys- sys-
tems that handle relatively small amounts of dust such as those for the frames and for the winders and twisters We have in mind particularly the indicated deficit of about 25,000 c.f.m. for the Picker House
Recirculation of air from dust collector systems where the dust is inherently hazardous to health is generally frowned on and we are among
those who usually discourage the practice This is because of the difficulty
of maintaining such equipment so as to assure the purity of the air returned However it is not often that there are economic incentives as great as in
the present case We believe an exception is warranted here and recommend
certain preliminary experimentation which will lead to an adequate system that will overcoms the objections usually encountered
It is recommended for this purpose that a small unit be constructed
for connection to the dust house or to a system serving Foster winders or
frames so that tests including dust counts in the effluent air can be con-
ducted The unit illustrated has bags 6 in diameter and about 7 long
providing a cloth area of approximately 10 sq ft per tube This unit can
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Manhattan Inc. Manheim Pa March 14,15,16,17
:
1944
15
be made with as many tubes as desired We show six for a total of 60 sq ft
and whose capacity may be anywhere from 100 c.f.m. to 600 c.f.m. depending
upon the application It is contemplated that the cloth will be plugged with
some inert dust preliminary to actual use for example limestone dust until
_-
.
its preliminary resistance is 0.1 to 0.2 inches at a filtration velocity of
1 f.p.m. This will probably require about 1/2 ounce of dust per sq ft of
cloth area
The design is illustrative only It may be advisable to increase
the size to fit an available blower Further to avoid the inconvenience of
finding a source of supply for the small quantities of filter cloth required
it is suggested that bags be ordered from a manufacturer of such collectors
in which case the metal collars and other pertinent dimensions of the housing
would be changed to accommodate the bags Either of the following is suggested
C. F. Berg Company
East Dedham Street Boston Mass
Parsons Engineering Company
3589 East 82nd Street
Cleveland Ohio
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Manhattan Inc. Manheim Pa March 14,15,16,17 1944
16
SUMMARY OF RECOMMENDATIONS
Picker House
1. Modify exhaust for pan crusher hoods providing 1250 c.f.m. y
per
hood
and
interconnected
hinged
doors
2. Repair cast iron cover on Lowell vertical opener where
dust leakage occurs
3. Consider the installation of a batching bed enclosure with
J
movable side and air exhaust in volume to create face velocity of 100 f.p.m.
See page4 and figure 1.
Carding Machines
4. Install curved trays under the feed rolls of the finisher
cards requiring them See page 5.
5 Construct experimental removable cover for one or two finish
cards for dust from upper wiper roll and rub apron See page 6. 6. Construct experimental hood for lower wiper roll and
rub apron Provide connection to exhaust system at a convenient location
for testing and another for attachment to one or two selected machines
See pages 6 and 7 and figure 2.
Air Filtration 7. Construct a model filter dust collector for efficiency tests
with arrangements for connection to dust house for ono test and to spinning
and twisting exhaust system for another See page 14 and figure 4. It would be advisable to complete most of the above prior to our
next visit especially Nos 1 4 5 6
j
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Raybestos Inc. Manheim Pa March 14,15,16,17 1944
17
ELECTRON MICROSCOPE EXAMINATION OF DUST
It was felt that an examination of the borne dust by the
electron microscope would throw some additional light on the fundamental
problem of asbestosis even though we draw no definite conclusions therefrom One school of thought maintains that the pulmonary condition results from a mechanical action of asbestos fibers on lung tissue yet the dust seen in
counting is almost all fibrous Through the courtesy of the research laboratories of the Aluminum
Company of America which is member of Industrial Hygiene Foundation
electron microphotographs of borne dust have been obtained and are
appended hereto The dust was collected with the electric precipitator in
|
the carding room
Two questions were propounded by us to the laboratory as follows
1. Are the cubical fibrous particles that are seen in the
light microscope used for counting actually composed of unbroken bundles
of fiber as in the parent rock Particles of this shape comprise over 95
of those seen and counted 2. Is there a large quantity of fibers whose length is several |
microns but which are invisible by the light field set because their
diameter is below the limit of resolution
The report included the following
INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC
Industrial ventilation survey of the U. S. Asbestos Div of
Manhattan Inc. Manheim Pa March 14,15,16,17 1944
18
The dust was found to contain many fibrous particles as well as
fibrous particles as shown in Fig 1. At the magnification used for this micrograph 5000X however the fibrous particles may appear to predominate This is not the case and no doubt results from the small size -
of the fibers as examination at high magnification shows that much of the
material is present as small fibers as shown in Fig 2 The fibers were
found to range in length from a fraction of a micron up to a few microns
with an average length of about 1 micron The thickness of the small fibers ranged from 0.01 micron to 0.05 micron 100-500 Angstrom units with the
average closer to the lower limit
The nature of the fibrous particles probably is as suspected -
'
that is they consist of bundles of fibers which have not been broken apart
This is evident from a few of the particles in Fig 1 and particularly from the particle in Fig 3. Several fibers protruding from the end of the large
bundle are shown in the latter micrograph
50001 50001 50001 50001 50001
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ener)
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