Document emK9DZQQRErQwDDkJwYVqb6Ne

Preliminary Dust Survey for Asbestos Tortile Institute, June, 19^7. 8 companies proves that It does not Interfere seriously vith manufacturing operations nor vlth quality of roving produced. Our investigations indicate the superior advantages of having side- valla of the enclosure of vood to facilitate email clearance by rubhlng con tact at the edge of the main cylinder, thus avoiding oxceeslve air infiltra tion at that point. Vood covers have the advantage of resistance to crushing, which vae evident in installations vlth sheet metal covers. Connection of the enclosure to the exhaust system by means of cham bers of dinensloos, l.e., large cross-sectional area la of major im portance to avoid localised high air velocities close to the vebblng in the _ cylinder. Oila detail vae not always observed. Tn view of similar degrees of success. Judged by dost counts, be tween various Installations, the best criterion of superior design as to de tails of exhaust from the vas in the relative econosy respecting, volume of air exhausted per machine. Our observations indicated rather extxese variations as Indicated in the following table of exhaust rates per eAyiMeg set In five representative plants: - Plant Air Exhausted Per Set A 1500 cfto B . 2200 cfb S 3800 cfb o 51*00 Cfb S 2000 cfb It 1b apparent from this investigation that 2000-2500 cfb per set of breaker finisher cards is ample exhaust capacity if the system is properly designed.