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1012 CHAPTER 46 1954 Guide Industrial Exhaust Systems 1013 Table 5. Exhaust.Requirements fob Woodworking Operations"(Air Velocity: 1000 /pm in all branches unless noted otherunse) Sell Feed Table Rip Saw ' , , . ,,, . - Use 1-5 in. branch at bottom pulley; 1-4 in. branch at saw head. Large Self Feed Rip Saws Other Than Table Saws Use 1-6 in. branch at bottom; 1-6 in branch at top. ^^ba*20 in. use 1-4 in. branch; over 20 in. use 1-4H in. branch. CiUrcpultaor 1S2awins. d i&m.............................................. :....................... ...................................................... 1-4 in. branch - .Over 12 in. di&m. .................. .............................. ........................................................................ 1--5 in. branch Dado head saws.................... .;....................... . ......... ...................................... 1-5 in. branch G V.blaSnrrSTdSepcnds on eBeettveness of hood and maximum number and diameter of saws. Disc Sanders Up to 12 in. di&m-- 12 in. to 18 in. di&m'. 18 in. to 26 in. di&m. 26 in. to 32 in. di&m. 32 in. to 38 in. diam. 38 in. to 48 in. diam. ........................... 1-4 in. branch ............................ 1-4)4 in. branch ................................ 1-5 in. branch -----............................-2-4 in. branch 1-4 m. branch and 1-5 in. branch 1-5 in. branch and 2-4 in. branch M` Uulptiptole3D1 rinu.mwSidaen.d.'e..r.s....(.o..v...e.r..t.h...e...t.a.b...le...).. .............. ........................................................ 5 in. branch (see note) 31 in. to 49 in. wide........ ......................... ....................................................... 6 in. branch (see note) 49 in. to 67 in. wide........ ..........................................................*.......................................... 7 in. branch (see note). Over 67 in. wide.......................... ......................................... ........................................... 8 in. branch (see note) Note: One branch of size indicated required for each drum. Fewer branch pipes may be used as long as total branch pipe cross sectional area is not reduced. Some manufacturers use 1 extra branch of equal site on feed side. 1-4 in. branch may be required for exhausting bed rubber cushions or mechanically operated brush. Single Drum and Spindle Type Sanders Up to 50 sq in. sanding surface............... - 50 to 200 sq in. sanding surface............... 200 to 400 Bq in. sanding surface............. 400 to 700 sq in. sanding surface......... 700 to 1400 sq in. sanding surface.............. 1400 to 2400 sq in. sanding surface.............. 1-3 in. branch 1-4 in. branch 1-5 in. branch 1-6 in. branch 1-7 in. branch 1-8 in. branch Table 5. Exhaust Requirements for Woodworking Operations (Concluded) (Air Velocity: IfiOO /pm in all branches unleu noted otherwise) Single rianera or Surfacers Up to 20 in. max. working width .. 20 in. to 26 in. max. working width. 26 in. to 32 in. max. working width. 32 in. to 38 in. max. working width. Over 38 in. max. working width 1-6 in. branch 1-7 in. branch 1-8 in. ^branch 1-9 in. branch 1-10 in. branch Double Planers or Surfacers Up to 20 in. max. working width... 20 in. to 26 in. max, working width. 26 in. to 32 in. max. working width. 32 in. to 38 in, max. working width. Over 38 in. max, working width -- 1 iJPper.h<iad ' Lower U7 n 't:nCt 1-5 'P- branch 1-g lJ n bSS'u P34"* i 10 in. branch 1-6 in. blanch 1-8 i!n". bbrraanncchh 1-8 in. branch Moulders, Matchers, Sixers (see Note) - Matcher head Up to 4 in...................................................................... 2-4 in. branch Top 1-5 in. branch Bottom 1-6 in. branch 4 to 6 in............................................................................ 2-5)4 in. branch 1-6 in. branch 1-6 in. branch 6 to 8 in........................................ ................................. 2-6 in. branch 1-7 in. branch 1-6 in. branch 8 to Note: 18 in............................................................................2-6 Where profiler is used, provide additional pipe not in. branch 1-8 in. branch lessthanthatspecifiedfortop head. 1-8 in. branch Wood Shapers 1-4)4 to 10 in. branch for each spindle according to size and character of work. Tenoner <- For cutoff saws: Up to 12 in. diam................................................................................ ,,. , Over 12 in. diam............................... ................................................................... UUssee 11--55 iinn.. bbrraanncchh mmiinniimmuumm.ffnorr each itnonp oanndJ Kbontitinonm. uten-onn,--c--o--p--e----a---n-jd dado head> . 1-4 jn branch 1-5 in! branch Automatic Lathes Use 1-3 in. to 1-10 in. branch according to work length. Hogs Air volume based on 50 cu ft per lb of refuse conveyed. Use 4500 fpm minimum conveying velocity. Floor Sweeps Use 6 in. branch for fine dust to 8 in. branch for coarse material. Mouth at fioor, 10 X 4 in. to 12 X 5 in.. . Note: Area of floor sweep pipe need not be included in computing main pipe area. Horizontal Belt Sander or Edge Sander (see note) Drive Pulley Idler Pulley Up to 6 in. wide.................. ................................................................................ 1-4)4 in. branch 6 in. to 9 in. wide............................................ ................................................... 1-5 in. branch 9 in. to 14 in. wide......................... .................................................................. 1-6 in. branch Over 14 in. wide............................................. ....... ........................................ 1-7 in. branch 1-4 in. branch 1-4 in. branch 1-4 in.'branch 1-5 in._branch Note: Where more than one belt is used, the pipe sizes specified shall be required for each belt. Where.* common hood is used for more than one belt, a single pipe of an area not less than the sum of the areas of Miscellaneous Equipment Pulley pockets and chain mortises-3 in. branch; dovetail add lock comer machines, dowel machines, duplex molding Banders, forming lathes, panel raisers (each head), ploughs, rail shears, routers, sash stickers (each headM in. branch; pulley stiles-6 in. branch; glue jointer-6 in. branch. theWpihpeerse sbpeelct iifsierdevmerasyibblee, upsipeed.at- i-dler pulley shall be the size specified for the drive pulley. . can be adjusted to required air flow rate, cfm, by use of a blast gate or orifice plate in such stub branch. VeTrJtpictaol B6 einlt.Swainddee..r.s....(.r..e..a..r...b..e...l.t..and...b..o...t.h....p..u..l.l.e..y..s.. .e..n..c..l.o..s..e..d..);..................................... 4)4 in. branch on bottom 6 in. to 9 in. wide........................................................................................ 5in.branch onbottom 9 in. to 14 in. wide.......................................................................................... 6in.branch onbottom 2. Arranging syBtem layout so future points can be picked up by a separate main which will run directly to the fan or air cleaning equipment inlet. Over 14 in. wide....... .................................................................... 7in.branch onbottom Band Saws and Resaws Up to 2 in. wide......... 2 in. to 3 in. wide....... 3 in, to 4 in. wide....... 4 in. to 5 in. wide....... Over 5 in. wide........... Jointers Up to 6 in. knives -- 6 in. to 12 in. knives. 12 in. to 20 in. knives Over 20 in. knives ... Bottom 1-4 in. branch 1-5 in. branch 1-6 in. branch 1-7 in. branch 1-8 in. branch 1-4 in. bramm 1-4 in. branch 1-5 in. branch 1-5 in-branch 1-5 in. branch 1-4 in. brao'* 1-5 in. breach 1-6 in. breach 1-7 in. breach CALCULATION OF SYSTEM PRESSURE LOSS The pressure loss of the system includes entrance loss37 as air is accelerated through the hood to a branch duct connection, resistance loss of ducts,38 elbows, and junctions, and acceleration or deceleration losses from velocity changes within the system. Chapter 32 includes data on duct resistance and on resistance of elbows, and provides sample calculations. In exhaust sys tems, either the equal friction method (illustrated in Chapter 32) or the use of blast gates in the branches to equalize pressure loss of all runs is em ployed.8'11 13 18 Data on losses for hood entrance and branch entry, transitions and weather hoods are given in Fig. 2. The static pressure in branch ducts close to the hood connection is frequently referred to as hood suction. It is the sum of the velocity pressure in the branch and the hood entrance loss.