Document YGmZeEvQXZBVByrr7QyDGwVJV

PRACTICAL IDEAS ...here's the trading post for your, operating and maintenance short cuts n STEVE SIONKA, Associate Editor Thawing Frozen Condensate Line j Safe Way to Blow Water Column Boiloi-watea column should be blown down at least every shifty It's the only sure way to know level shown is correct. Fire-room foreman In photo is blow* ing column from upper plolform. Upper and lower cocks on gage glass have long reach rods to catwalk. By turning valve lever on end of rod, reach rod revolves, actuating valve. To blow a column correctly, close top cock and open drain valve on blowdown line. Then all water blows through bot* tom cock. Close bottom cock, open top, so only top cock blows. Now make sure both cocks are open. Close drain valve on blowdown line. This la only suro way to dear both gage-glass connections. Many tubes have failed because a column connection was plugged--given false reading In glass. Bill Davis National Safety Council, Chicago, HI, When 1200 feet of 3-in. diameter co.' dentate line from our mill froxe, hooked on 400-amp capacity weldlo| machine. After two days, not even i hundred feet thawed. We called on local power comptaf to give a hand. They had a 37.5-kri single-phase transformer and aotDe< 0000 cable they hooked to 4900-v top-' ply. Secondory of 20-1 ratio tram-; former was hooked on to 3-in. pipe and we went to work. We didn't get for until one of our men' noticed an aro running down supponrods on pipe hangers, aketch. Thai showed current was flowing throat 3-In., Bin. and 12-ln. pipes--greatly reducing heating effect After plseing* wood blocks under S-ln. pipe stl alon|! hangers, as shown, entire pipe thawed ' in only three hours this time. C E Boyhan Ticonderoga, N. Y. Automatic Beater Unplugs Coal Chute We had thouolk with chutes beneath belt acrapera on our cool conveyor belts. They became plugged when handling wet 'eoal. Fine wet coal removed by scrapers built up in chute, didn't flow. To eliminate trouble, we buiti the chute beater shown. Cross shaft and beater, arm are made of %-!n. double strength pipe. Roller contact arm is a 2-piece arm of short pieces of %*iu. pipe welded to the cross shaft. A %-ln. nicklo chrome nut's welded onto upper end. By using a short length of %4n. rod threaded to fit this nut, contact arm can be adjusted to vary length of beater arm's stroke. Beater head is a piece of 1-in. pipe about 3 in. long, with 2 pieces of rubber hose over ends that prevents melal-to- metol contact from wearing chute. Tripping roller is a 3-in. ball bearing, mounted on a supporting bracket. Bracket in turn is welded to inside of runvuyor-bcll pulley. Ueurings for cross shaft are small lengths of 1-in. pipe, supported by arms welded to conveyor frame. This beater works like a charm. 0 IloKSCir fronting, Iowa Brush Marking Mark a thin link with while or yellow'.] paint across face of motor and genera-1 lor brushes used In box-type bruit1 holders, as shown. Place line on brush , so bottom of holder box will coincide with line when briiihei reach the end , of their wearing distonce. Then lint*, for brush'replacement Is automatically indicated. When the colored lino sp pears below the edge of brush-hold6* box, replace the brush with new. T TnsiL Ceionsvtlle, AM- ' 124 PUNT OPERATION AND MAINTENANCE SECTION POWB Handling Acid Safety . hav sutruwc acid stored outside In a 10,000-gal tank. Acid was piped fronbouom of tank to measuring tank loildo building. Method of handling created`various hsxards. To overcome, we installed a siphon, sketch. To start siphon, wo .made aspirator out'of pipe, sketch. But acid waa so heavy that we bought o more efficient aspirator. Thla one works on com pressed air. By using this setup, a break in Uno above ocld level In 10,000-gal taak will break only the siphon. It's so piped that acid leak below level will run into measuring tank. When the line plugs, we open union, and- either rod out the lines or take them down to clean, or replace. No worry about acid flying over someone. K:M-White Clinton, Iowa Steam Cushions Better Than Air Chamber Trouble developed in a steam-pres sure-reducing and desuperheating sta tion. Pressure was 400 psl, at 700 F, which was to be reduced to 150 psl sat urated. A variable-displacement pump driven by an electric motor furnished water (or cooling spray, but water hammer set up in this pump. Hammer was so severe that we used boiler feed-pump instead. This set of! a aeries of troubles. . I'll only mention a few. Water hammer was severe and dastructive. Oil lines on pump broke off at fittings. Air control lines for de superheating station also failed. Piping throughout plant vibrated, and controls were erratic. No one would risk oper ating pomp for more than 10 or 15 min. Pump had been installed with a non- slam check on discharge. Later a T had been installed with an air chamber, drain and valve on lop of chamber to admit air when the chamber waa drained, sketch. It was easy to check that little air spaee remained in chamber when pump operated at 500 psl. So remaining air was quickly absorbed. This was checked by installing a gage glam. U waa my belief that If air chamber was lorge enough, water hammer would stop. Wo installed new chamber. It is not filled with air, but with steam, which is formed by evaporating the water with a steam jacket around chamber. Jacket Is filled with steam at 400 psl, 700 F. Theory proved correct as there's no further trouble with water hammer. E H Roper Toledo, Ohio Sketch snows method I use for getBug Indicator reading on grid spring- ttoplinga. Thla method It reliable, also wy simple and compact where cou plings are close-connected. There's lit- w enanco of getting o false reading os wilh makeshift devices. Easy attach- for a quick check on shutdown la p b toie* amP ! easy to make. K R -Bstccs Dunedin, Fla. Cutting Out Boiler Tubes First, cut tuoe to be taken out, as shown. Then knock up towards center, which usually makes tube easy to with draw. Take care not to out all the way through tube or you might harm the tube sheet. Collapse tube all around. T H Carr Shipley, Eng. (Continued on page 126) JANUARY 1951 PUNT OPERATION AND MAINTENANCE SECTION 125