Government of Kerala. Department of Factories And Boilers Boiler Operation Engineers' Examinationo July 2012 Paper-1 Maximum:100.

Transcription

1 Government of Kerala gco At 9 Department of Factores And Bolers Boler Operaton Engneers' Examnatono July 2012 Paper-1 Maxmum:100 Part-A (Answer all questons) Each queston carres 5 marks,1. What are the dfferences between Boler mountngs and accessores? Gve 3 examples of each.,2.whals the functon of chmney n natural and artfcal draught system? - 3. What are the merts and demerts of fre tube bolers over water tube bolers? of fludzed bed combuston boler over,fxed grate boler. -4.Lstadvantage 5. Determne the amount of heat whch should be suppled to 3kg of water at250c to convert t n to steam at 5 bar and 0.9 dry 6. What are the factors that depend on the type and sze of bolers? u7.how the boler effcency can be rased?.,z 8. Defne boler horsepower and equvalent evaporaton' (8X5:40) Part-B (Answer any fve) Each queston carres 12 marks 9. Draw the workng sketch of a typcal boler and show the poston of varous boler mountngs and ts parts. 10. Determne the heght of chmney to produce statc draught of 25mm water, the mean flue gas chmney s ZZ0OCLd the atmoptrec ar temperature s?00c, barometer reads 760 mm Hg, the characterstc of gas constant for ar s 287 Nmlkg0 K and for chmney gas t s 255.N{. Nm/kgo K. Cve an outlne sketch showng the arrangement of water tubes furnace of a Babcock and Wlcox boler. ndcate on t the path of the flue gases and water crculaton? \r absolute from feed water at 750C.The calorc value of fuel s 4381ftlkg and the overall thermal effcency s 80 %. -rl1l. Explan the workng of the followng ) Economser ) Feed check valve ) Water level ndcator. /14. What are varous types of draughts used n usual practce? What are the advantages of artfcal draught over natural draught?. 15. Explan why safety valves are needed n a boler? Draw a neat sketch of lever safety valve and explan ts workng?. A2. Calculate the quantty of fuel ol requred, generatng2.5kg/s of a 0.96 dry steam at l5 bar PTO

2 rtr- / Tme :3 Hours Governrnent of Kerala Department of Factores And Bolers Bo l e r o pe ra tot n t*t;;:t;_f." - n aton o J uty 2012 Part-A Maxmurn:100Ma fl p',k{ A. -t1.. What you mean by steam purty? "".$n",j,",;'l#:::'1"*.*,12. Wt at s the mportance of water treatment n a boler? -rtrwyruts a super crtcal boler? What are ts merts and demerts? V. Cu" the classfcaton of stokers. ls.what are the basc requrements of combuston equpment? $. fstvarous materals used n a boler desgn..,/7. Suggest some methods to reduce smoke n boler fumace. Wh"t s PH value? How s t controlled n water? Part-B (Answer any fve) Each queston carres 12 marks " (8x5:40) r-d. Wltfr the help of neat dagrams, dscuss varous methods of ash handlng. 0. Expan genera methos employed n ayng foundaton for bolers. 1.. Explan wth neat sketch the workng of a spreader stocker. {p. Descrbe the role of a boler operator. - l. Dscuss dfferent alrangement of burners n a pulversed coal fred furnace. \4. explan varous energy savng opportuntes n a boler plant. ufs. What are the precautons to be taken for startng a boler? 6. 1a;.Wtrat are the benefts of provdng an Economser n a Boler? (b).calculate the fuel savngs by provdng an Economser for Boler. The performance data of boler are gven below. Averase ouantlv of sleam generated A,rerale d.eg"; tem perat u-re Average steam generaton/kg of fuel gff*;*r n et tem peratue - - Fuel ol supply rate Fdolgas quantty Gross calorfc value of ltel Rse n feed water temperature by Provdng economzer Annual operatng hrs 5T/h 3 1 5oC (wthout economzer) 14kg 1100C 3l4kglhr 17.4kglkg of tue 10000kcal/kg 200c 8600 (5x12:60)

3 r- a Evaluate the opton of'bol". r"placement for the followng boler wth a new boler g4% effcency. The cost of new boler s Rs.30 lakhs. Data for present boler Average steam generaton from boler: 5000kglhr Fuel used : Furnace ol Enthalpy ganed by the steam n boler: 600kcalrkg of steam Cost of furnace ol Gross calorfc value of fuel Annual operaton hours of boler: Boler effcency: 80% : Rs.35000per ton : l0000kcal/kg 6000 hrs (5x12=60) -::::=:_--

4 GOVERNMENT OF KERALA DEPARTMENT OF FACTORES & BOLERS o./ BOLER OPERATON ENGNEER'S EXAMNATON $.,/?-, ot./ -{/ r Paper - ll! - Drawns / Tme :3 Hrs 1. Assemble and draw the followng vews of a Steam Stop Valve. The detaled drawngs of the components are gven below l. A Rght half sectonal Elevaton Marks : 100 (Mox. marks-75) ( Max. marks - 25 :j-!'l : -f a',*- c. \. n;n r1t-5-'h* -f 1l 6t.>_ t /-\ f-1- Q/., l-?! 'j.. s2( {w1 \ rl ':'.\ -, - l- (f s;. r)l a-r;' jv l D t- j {x '-. '-.\. t,1 kv e!q'-- \ *--.-.:!,r-. -vjj F- j f- -l.t :tl ^r'dnz:-l rat l, L,!.q.r-+, tlo r t1 r-zl,t /.'-{'\ Bl vt!tn \tl t',\ W;t- \'-::-\./ l.---,- *\-;/r: ct00 ( l3l 1r4)

5 t,a a GOVERN1ENT OF KERALA DEPARTMENT OF FACTORTES & BOLERS BOLER OPERATON ENGNEER'S EXAMNATON Tme :3 Hrs - paper_ lll _Drawng 1' Fgure ff;::$"jjl',""jr :;"":,::;.- Varve. Assembre and draw the.fo'owng vewsmarks : 100 '. A plan ( Mox. marks _ 75 ) ( Max. morks _ 25 ) vj _ t ** ***^*.*_? -23q