Document RJpjzjjXmwMmxa04z4pMz7bq8

340 W. N, WITHERIDGE H. PNEUMATIC CONVEYING SYSTEMS Light bulky materials, such as wood shavings, textile fibers, paper lllll ground cork, and grain products, can be transported by air without! power requirements and without damage to the materials or conveying |pj Conveying velocities may be of the same order as for dust-handling-sM they may be much higher, as indicated in Table 15, with resultant the power requirement. The quantities of air required for pneumatic.^ vary approximately from 100 cu. ft. per pound of light fluffy material "open cotton" at 3000 l.f.m. to about 25 cu. ft. per pound of heavy solid at 8000 l.f.m. I. CONSTRUCTION SPECIFICATIONS FOR VENTILATING SYSTE| The designer should obtain the codes and standards that apply, industry, state, or trade association to be certain that his preference^ conflict with locally established practice. It is not possible to formulate. SM& specifications that will have nation-wide acceptance without removing'yil^ the details that would be of interest. Furthermore, construction materiajs'`j|||| and standards are improving yearly. The annual Guide of the American Society of Heating and Air-Gonfl ing Engineers is suggested as a source of information on construction feajujiH will be kept reasonably up to date by the frequent revisions authorities-among--the--Society's--membershipr'Tlre-"Committee Ventilation of the American Conference of Governmental Industrial ^Jfpl has published a loose-leaf reference book incorporating the recommend^ industrial hygiene engineers on construction and use of ventilating|| Among state codes, the most widely publicised in the field of induitnaj| tion are those prepared by the Division of Industrial Hygiene of the.fjg State Department of Labor. The American Standards Association's ;4ist| proved and adopted codes on ventilation is already substantial and'fr to grow. It is an increasingly important source of technical and design iniojjm| as professional organizations assemble their material for submission rt6pilj] ------------------------ -j~MAlNTENANCE''OF"VENTIL~ATffiG~EQUIPMENTf^, Too" frequently the designer has no further control over system after it is placed in use. Whether he made provisions for aitci _ mmt additions, or issued, instructions that no change must be made-wfUioiit AVyr'ew; of the design, the fact remains that sooner or later something will J,be upset the original plan, and place new burdens upon the fan, work for which they were never prepared. Accordingly, the alett.r.edfcjjijl investigator will proceed with caution when appraising the original a Siim1& VENTILATION 341 PsB^Sinnuf-iIrmSiaaeprbrgiaasobleeil,ee affianaadinilluumtrrheecisss0 iinanpmmplieeeccsihmatou_ni_iucn_ma_el_avVrleCynilUteilllvWaetUrioyivnupaarreVt due to --______ of the inadequate care ssvysstteemm,, wwhheetthheerr m' '!''."Qi;$ationary. When it is realized that contaminated air is in constant fc'iugh the hoods, ducts, cleaners, and fan, it is readily appreciated that &^,S^:r|Jiandling equipment should be classified as dynamic rather than duets would settle this point beyond doubt in many cases. OT-tnAiVlffhe best assurance that mechanical ventilation is functioning v'**' , fcheme of periodic inspection and testing. Volume III outlines the libds of observing and measuring air flow. Successful maintenance Ss'iViffSf,'rl.''liave learned to use these reliable methods of measurement to ensure .. . 'Vformance. General References of Industrial Exhaust Systems. 2nd ed., Industrial Press, New York, 194S. i"thence of Governmental Industrial Hygienists, Committee on Industrial Yen- iTritt^/nrluctrial VVeennttiillaattiioonn,. 4etthn eeda..,, Luatmnsoiinug^,, Mich., 1--9--5-6--. Bfaw". `Ifntvd,ustrial Health Ewn-ng/inineneerringa. Wilevy., New York, 1947,. The Industrial Environment and Its CCoonnttrrooll.. PPiittmmai n, New York, 1948. T F. Hatch, Industrial Dust. 2nd eedu..,, MMccGGrraaww--HHiillll,, New York, 1954. ............ , _Practical Design oj Exhaust and BBllower Systems. E. A. Scott Publishing I^li^ri$Mwnn>, Nj. Yv., 1935. Ii., Plant and Process Ventilation, Industrial Press, New York, 1955. F. B. Morse, Ventilation Manual for Sheet Metal Contractors. E. A. Scott ilfoorpTarrytown, N. Y., 1955.