Document KGMqD2xqNwxn3q9E9pyBvEGDK

American Society of Heating and Ventilating Engineers Guide, 1924-25 TABLE 107. SIZE OF CONNECTIONS FOR WOOD-WORKING MACHINERY Type of Machine Circular Saws, 12-in. diam.~...............-..... J..................... Circular Saws, 12-24-in. diam........................ ......... :....... Circular Saws, 24-40-in. diam..........-............................... Band Saws, Blade under 2.in. wide.................................. Band .Saws, Blade 2-3 in. wide._...................................... . Band Saws, Blade 3-4 in. wide._..... ............... .................. Band'Saws, Blade 4-5 in. wide.......................................... Band Saws, Blade 5-6 in. wide._....................................... Small Mortisers..._............................................................... Single End Tenoners................................ ....................... Double End Tenoners....................................................... Double End, Double Head Tenoners............................... Planers, Matchers, Moulders, Stickers, Jointers, etc.-- With Knives, 6-10 in........ ........................................ With Knives, lO-^O in................................................ With Knives, 20-30 in.... ..... ...................................... Shapers, Light Work.......................................... ................ Shapers, Heavy Work........................................................ Belt Sander, Belt less than 6 in. wide.,............ .............. Belt Sander, Belt. 6-10 in. wide..... ................................. Belt Sander, Belt 10-14 in. wide................. ..................... Drum Sander, 24 in.._......................................................... Drum Sander, 30 in.................... .................. ..................... Drum Sander, 36 in............................................................. Drum Sander, 48 in.............. ..................... .............. ........ Drum Sander, over 48 in.................................................... Disc Sander, 24 in. diam.....................,.............................. Disc Sander, 26-36 in. diam............................................... Disc Sander, 36-48 in. diam..;..................... ...................... Arm Sander................ ....... ............................. ......... ......... Diameter of Connections in Inches 4 5 6 4 5 6 .7 8 6 6 7 10 5-6 6-8 6-10 4-5 8 5 6 7 6 6 7 8 10 5 6 7 4 TABLE 108. SIZE OF CONNECTIONS FOR GRINDING AND BUFFING-WHEELS Diameter of Wheels Grinding-^ 6 in. or less, not over 1 in. thick......... , 7 in. to 9 in., inclusive, not over iii. thick...... 10 in. to 16 in., 2 in. " . .. 17 in. to 19 in., " " " 3 in. " ...... 20 in; to-24 in., " " "4 in. " ...... 25 in. to 30'in.,' " " "5 in. " ...... Buffing-- 6 in. or less, not over 1 in. thick.......... 7 in', to 12 in., inclusive, hot over 1 in. thick...... : 13 in. to 16 in., " u "2 in. a . . . 17 in. to 20 in., 3 in. " . .. 21 in. to 27 in., " " ' " -4 in. " 27 in. to 33 in., - " " " 5 in. " .. . . . Max. Grinding Surface Sq. .In. 19 43 101 180 302 472 19 57 101 189 338 518 Min. Diam. of Branch' , Pipes in . Inches ; 3. . 3'A , 4 4H 5 6 3A 4 4A 5 6 7 210 American Society of Heating arid Ventilating Engineers Guide, 1924-25 Tumbling barrels have connections ranging from 4 to 8 in., bucket con veyors 6 to 12 in., and screening machines 6 to 10 in. In general room exhaust large connections should be provided so that the air may be handled at low velocity and with a minimum power con sumption. After having determined on the proportions of the exhaust system as regards hoods and connections it is then necessary to choose the air velo city or suction at the hood connections, suction at the hood connections being a measure of the air velocity at that point. Fig. 71. Exhaust and Conveying System Handles Waste from WoodWorking Machines AIR VELOCITY The air velocity required is dependent upon the specific gravity of the material, the fineness of the particles, and their physical characteristics. Certain materials such as grease wools, silk waste, salt, and other hydro scopic substances are difficult to handle due to the tendency to deposit in the conveyor pipes. While the velocity in the system should be sufficiently high to insure the removal of the material it should be kept as low as practicable since any higher velocity requires the use of unnecessary power. With a fixed system or orifice the power increases as the cube of the increase in velocity. Velocities commonly employed are: 2,500 to 3,000 ft. per min. for light dusts, cotton, shavings and sawdust from dry wood, and similar substances. Heavy dusts, wool, shavings and sawdust from wet wood, rags, waste paper and similar materials 3,000 to 4,000 ft. per min. Lead dust, hog waste, pulp chips, etc., 4,000 to 6,000 ft. per min. 211