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FILE NAME Industrial Hygiene Foundation IHF DATE 1944 Mar DOC IHF080 DOCUMENT DESCRIPTION Excerpts - Report of Industrial Hygiene made for Manhattan with Cover Letter os e ae INDUSTRIAL HYGIENE FOUNDATION OF AMERICA 4400 Fifth AvenUE PITTSBURGH 13 April 18 1944 Mr. O. H. Cilley Asst Gen. U. S. Asbestos Division Raybestos Manhattan Inc. Menheim 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 continuing 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 a ; 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 Measure- 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 JEM ends . SOn ey? EO op S John F. McNabon Managing Director LF. ere. FOR THE CONSERVATION OF EMPLOYEE HEALTH IN INDUSTRY bth INDUSTRIAL HYGIENE FOUNDATION 4400 FIFTH AVENUE OF AMERICA INC PITTSBURGH PA REPORT OF INDUSTRIAL HYGIENE SURVEY MADE FOR United States Asbestos Division of Raybestos Inc. Manheim Pennsylvania March 14, 15, 16 and 17 1944 W.C.L. Hemen FIELD WORK BY ............. Ventilation Engineer LABORATORY WORK BY Francis R. Holden Ph.D.Ph.D., Industrial Hygienist April 1944 O < INDUSTRIAL HYGIENE Foundation OF AMERICA Inc. Madison Madison 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 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 oquipment is probably not in itself sufficient to account for any markod s a 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. Manhoim Pa March 14 15 16 17,1944 TABLE I Dust Counta Samplo 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 P 2 3/14/44 3/14/44 3/14/44 : 33 22224 33 P 4 3/17/44 50-10 42A 23 3/14/44 59-3 P . 26 : 3/134/14/44/44 1 17 7 3 P 3 I 3/15/443/15/44 54-11 , , 3/15/44 1515 11221 1 55A A ESP 11 3/17/44 1049-411 949--11 11 : 49A 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 fooding vertical opener Ex- posure of operator within booth 52 minute sample at central point of room for general air near vertical opener Carding General air walking about various carding machines in Breaker Card Room Besido point of discharge from con- 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 Between finisher 15,16,21,22 cards All windows of carding carding and 15,16,21,22 15,16,21,22 spinninspginning room open wide to simulate summer con- ditions oops Particles per cu ft 8.7 million 1.7 million 38.0 million _ 9.9 9.9 million million million million 5.6 millio 4.0 million millior 3.3.8 8 mmiillliloiror 4.3 million million 4.8 milliominllion millio 2.8 2.8 2.8 : millio 3 4 10 8 Note 3/15/44 48-151 8A ; 3/15/44 10-1 P 3/15/44 3/15/44 3/15/44 556-6 1 -: 1 P 50-2 P 119 9- -2 2 P 3/15/44 45 Spinning and Winding At mule spinner while following oper- stor to simulate his exposure At Universal winders 2nd floor ad- joining cards-cards- following operator exhaust At Foster Winders Average of all aisle At Twisters Average of all aisle At frames on 2nd floor AveraAgveragoo along aisle At 2 frames frames on 1st floor . AAvveerarge age along aislo 4.8 millio 3.0 millio ; 3.6 millio 4.0 millio millio 3.3.6 6 millio: millio 2.0 millio _ All samples with Midget Impinger except those marked ESP Flectrostatic 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 2feet wide by 2feet 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 countosf Samples 27 and 19 indicate that the two workers stationed outside the booth are not exposed to important dust concentrations but that the man who feeds the vertical opener within the bootihs 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 Johnson's Johnson's grader waste machine and willow were not in operation at the time of our studies 4 INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC . 5 Industrial ventilation survey of the U. S. Asbestos Div of Raybestos Inc. Manheim Pa March 14,15,16,17 1944 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 | Card No. _ Observation are as follows OK 72 Fair but needs front to complete enclosure . OK *** Dusty OK Dusty Dusty OK Dusty 22 ---- 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 Raybestos 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 25 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 control be 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 provido for : 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 slot the length of each section and, c elimination of excessive cross-sectional area the transition section in order to maintain adequate velocities for the transport of in material 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 properfunction | 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 following table they vary quite widely INDUSTRIAL HYGIENE FOUNDATION OF AMERICA INC B. 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 Taking Damper Adjustment as Found Unit Static suction Air Flow 1 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 " " " " " " " " 920 670 515 590 420 210 510 840 790 c.f.m. " " " " " 7 " 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 Raybestos Inc. Manheim Pa March 14,15,16,17 1944 ' AIR EXHAUST AND SUPPLY IN VARIOUS DEFARLINTS 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 lir Bertelet and Mr. Gilpin Exhaust Ceracity Ceracity in Picker House Unit 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 Total Capacity 2500 2900 6000 c.f.m. C.f.n. c.f.m. 3400 c.f.m. 2900 c.f.m. 2400 c.f.m. 2500 c.f.m. 22600 c.f.m. Unbalance in Card and Spinning Department 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 system frames newer systemI - estimated Total . 17,000 13,000 13,000 c.f.E. 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 capacity 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 minute was 3100 fect per minute and in the latter case 2970 feet per 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 may be expected by reducing the resistance by 0.4 inches One would FON, hardly expect material difference in the operation of the exhaust system mene * with such a small percentage increase in air flow ae, Dust sample ESP 11 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 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 61 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 follows Foster Winders East Fan West Fan Twisting Machines North Pan South Fan Cop Winders Total - 3300 c.f.m. 3330 c.f.n. 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 Raybestos Inc. Manheim Pa March 14, 15, 16, 17 1944 RECAPITULATION 17447 AIR EXHAUST AND Exhaust Potential SUPPLY Total Supply c.f.m. . c.f.m. Existing Carrier Unit Existing Carrier Unit Carding Source Picker Breaker and Spinning Twisting Department 33,600 33,600 . Card Room Overflow avail 33,600 House 22,600 22,600 Room 12,000 17,800 modified 58,0 0 58,000 36,000 f modified from Twisting Department Required portion from } 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 Manhattan Inc. Manheim Pa March 14,15,16,17 1944 14 AIR FILTRATION An effective dust collector which will produce clean air i.s. 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- 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 und 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 overcome 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 " 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 Raybestos 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 ee 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 ING Industrial ventilation survey of the U. S. Asbestos Div of Hanhattan 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 J - 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 ocllector 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 % 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 a 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 ene mento erat mete e t e awe, ! i ' 2700 2700 borne borne borne 300077 300077 300077 300077 300077 a ree cane ee tA nes kee teeters cet am ee ee neem we he rere 2 --- ---