Environmental testing of an advanced flare tip for a low-profile flare burning ethylene

American-Japanese Flame Research Committee Joint International Symposium Advances in CombustionTechnology: Improving the Environment and Energy Efficiency Marriott Waikoloa, Hawaii October 22-24, 2007 " E n v ir o n m e n ta l T e stin g o f a n A d v a n c e d F la r e T ip fo r a L o w -P r o file F la r e B u r n in g E th y le n e " S. Smith, J. Modi, J. M. M cD on ald & C. Little (Zeeco) and J. D. Smith & L. M. B erg (Alion Science and Technology) A bstract A s p a rt o f th e d e v e lo p m e n t o f a n e w a d v a n c e d flare tip fo r a L o w -p ro file fla re field , se v e ra l e x p e rim e n ts h a v e b e e n c o n d u c te d to e s ta b lis h th e fla m e h e ig h t/sh a p e , th e sm o k e le ss p e rfo rm a n c e , a n d th e ra d ia n t flu x p ro file fo r w in d a n d n o -w in d co n d itio n s. Z e e c o 's f l a r e t e s t f a c i l i t i e s h a v e t h e a b i l i t y t o fire s in g le a n d m u ltip le tip s to e v a lu a te b u rn e r sp a c in g , firin g ra te s, fu e l ty p e s , a n d ra d ia tio n flu x fo r a sp e c ific fla re tip d e sig n . W o r k p e r f o r m e d in th e c u r re n t te s tin g in c lu d e d a s in g le b u r n e r te s t w ith tw o d iffe re n t tip d e s ig n s a n d a th re e -b u rn e r te st w ith th e sa m e tip d esig n . h e ig h ts a n d sh a p e s as e x p e c te d . T h e se re su lts s h o w fla m e R a d ia n t flu x e s fro m th e sin g le a n d th re e - b u rn e r te sts also p e rfo rm as e x p e c te d . D a ta fro m th e s e te sts w e re u s e d to h e lp v a lid a te C F D p re d ic tio n s p e r f o r m e d fo r th e s e te sts a n d a p p lie d to a fu ll flare fie ld calcu latio n . In t r o d u c t io n In 2 0 0 6 , Z e e c o re c e iv e d a c o n tra ct fro m a m a jo r c h e m ic a l c o m p a n y to d e sig n a n d su p p ly a la rg e m u ltip o in t g ro u n d flare sy ste m fo r a m a jo r g ra ss ro o ts o le fin s fa c ility in th e M id d le E a st. T h e p ro c e s s r e q u ir e m e n ts fo r th is fa c ility a re v e r y strict, a n d in g e n e ra l, o u ts id e th e n o r m a l ra n g e o f c o n s tra in ts a n d p ro c e s s re q u ire m e n ts th a t a re a p p lie d to m u ltip o in t g ro u n d fla re sy ste m s fo r such p lan ts. Zeeco agreed to su p p ly th e sy stem and m e e t th e p e rfo rm a n c e a n d te s tin g a n d m o d e lin g re q u ire m e n ts th a t w e re d e fin e d in th e c u s t o m e r 's s p e c i f i c a t i o n s . T h is in c lu d e d fu ll sc a le firin g o f th re e (3 ) b u r n e r tip s. B a c k g r o u n d o n M u l t ip o in t F l a r e s M u ltip o in t s ta g e d g ro u n d fla re s y s te m s h a v e b e e n u s e d in th e re fin in g a n d p e tr o c h e m ic a l a n d p r o d u c tio n in d u s trie s s in c e th e y w e r e first c o n c e iv e d in t h e e a r l y 1 9 7 0 ' s. T h e o v e r a ll c o n c e p t o f th e s e s y s te m s is to s p r e a d th e c o m b u s tio n o v e r a la rg e a re a to fa c ilita te air ac cess. T h e se sy ste m s w e re firs t u s e d in th e M i d d l e E a s t, a n d o th e r m a j o r o il p r o d u c ti o n a r e a s as C a n d le AFRC-JFRC October 2007 Zeeco Inc. F l a r e s ( s e e F i g u r e 1 ). T h e o rig in a l s y s te m s w e re v e r y sim p le , a h o riz o n ta l p ip e m a n ifo ld w ith m u ltip le v e rtic a l p ip e s th a t w e re u s e d as b u rn e rs. o rig in a l sy stem s had no stag in g and d id not have d e fin e d T hese b u r n e r tip s. Ig n itio n w a s d iffic u lt, th e r e w a s little f la m e sta b ility , a n d th e s y s te m s w o u ld sm oke. lo w e r T h e o rig in a l g o a ls w e r e to s o m e w h a t im p r o v e c o m b u s tio n , a n d to th e m ajo r ac co m p lish e d . c o m b u stio n clo ser to g rad e, w h ic h w as g e n e ra lly N o t e all o f th e s e o rig in a l s y s te m s w e r e b u r n i n g p r o d u c e d gas, w h ic h c o n siste d o f m o d e ra te m o le c u la r w e ig h t m ix tu re s o f satu ra ted g as c o m p o n e n ts. F I G U R E 1: C a n d le F la re T h e se sy ste m s h a v e b e e n sig n ific a n tly im p ro v e d o v e r th e y ea rs. sy ste m s use S y ste m s are p ro v id e d b u rn ers to a very w ith in d e fin e d a know n p re s s u re s fo r th e sy stem . 2 w ith burn er tip , sta g in g , to pressu re w ith lim it th e fla m e sh a p in g o p eratin g e n v e lo p e , th e u p sta g e C urrent a b ilitie s. ran g e and o f th e d estag e AFRC-JFRC October 2007 Zeeco Inc. B u rn e rs are a rra n g e d in g ro u p s , u s u a lly ro w s , a n d th e o p e ra tio n o f e a c h o f th e s e g r o u p s o r r o w s is c o n tr o lle d t h r o u g h th e u s e o f a q u ic k o p e n in g s ta g in g v a lv e , u su a lly h ig h p e rfo rm a n c e b u tte rfly v a lv e s. e q u ip p e d w ith n u m e ro u s T h e v a lv e s are u su a lly sa fe ty fe a tu re s, s u c h as sp rin g to open d e sig n , b a c k u p a ir c y lin d e r s m o u n t e d o n e a c h v a lv e , fa il o p e n o n lo s s o f p o w e r o r lo s s o f i n s t r u m e n t air, etc. In a d d itio n , to e n s u re th e sa fe ty o f th e u p s tre a m fa c ility fo r a n y a n d a ll c ir c u m s ta n c e s , e a c h o f th e s ta g in g v a lv e s is a ls o in s ta lle d in p a ra lle l to a s a fe ty r e lie f d e v ic e o f s o m e ty p e . T h e s e sa fe ty re lie f d e v ic e s c a n b e ru p tu re d iscs, c o n v e n tio n a l re lie f v a lv e s , p ilo t o p e ra te d r e l i e f v a l v e s , l i q u id s e a l d r u m s , r u p t u r e p i n v a l v e s , etc . F I G U R E 2 : ________ M o d e r n S t a g e d M u l t i p o i n t F l a r e T h e f u n c tio n ( o p e n o r c lo s e d ) o f th e s ta g in g v a l v e s is c o n tr o lle d b y a d e f in e d program . T h is p r o g r a m lo g ic is lo c a te d e ith e r lo c a l to th e fla r e s y s te m in a l o c a l l y m o u n t e d P L C s y s t e m , o r i n t h e p l a n t 's D C S s y s t e m . th e lo g ic are flare g a s flo w , o r flare g a s p re ssu re . T h e in p u ts to T h e s e in p u ts, in a d d itio n to th e g a s flo w a n d c o m p o s itio n a n d te m p e ra tu re in fo rm a tio n fo r th e flare s y ste m , w o r k to d e te rm in e w h ic h o f th e b u rn e r g ro u p s o r c o m b in a tio n o f b u rn er groups sh o u ld be in s e rv ic e to ensure th e d e fin e d / re q u ire d p e r fo rm a n c e p a ra m e te rs are m et. F ig u re s 2 a n d 3 s h o w a ty p ic a l m u ltip o in t sta g e d g ro u n d flare sy ste m w ith a fu ll e n c lo su re fe n c e . o f th e sy stem 3 T h e s ta g in g m a n if o ld is ty p ic a lly lo c a te d o n o n e sid e o u tsid e th e fe n c e , w ith stag in g v a lv e s, ru p tu re p in v a lv e s, AFRC-JFRC October 2007 Z eeco Inc. M u ltip o in t b u rn e r b lo c k v a lv e s , m a n if o ld s fo r u tilitie s , a n d c o n tro ls. r u n n e r s a re r o u te d fro m th is p o in t in to th e f e n c e d area. 1----- 1-r -----r----- 1----- + I r -+----- 1"-----r -*------ 1- r - 1 i~ r F I G U R E 3 : ________T y p i c a l M u l t i p o i n t F l a r e L a y o u t T h e d e s ig n e r o f th e s y s te m h a s a n u m b e r o f v a ria b le s th a t m u s t b e r e v ie w e d a n d fix e d to e n s u re th e s y s te m o p e ra te s p ro p e rly . T h e s e v a ria b le s a re a f u n c t i o n o f t h e s p e c i f i c f l a r e c o m p a n y t h a t is p r o v i d i n g t h e e q u i p m e n t , h o w e v e r, in g e n e ra l, th e s e a re : 1. B u r n e r t i p t y p e 2 . B u r n e r t i p s iz e 3. F l o w r a t e p e r b u r n e r t i p 4. B u r n e r tip f lo w a re a 5. B u r n e r t i p d r i l l i n g p a t t e r n 6. B u r n e r t i p s p a c i n g 7. B u r n e r tip e le v a tio n a b o v e g ra d e 4 Z eeco Inc. AFRC-JFRC October 2007 8. B u r n e r r o w o r g r o u p a r r a n g e m e n t 9. S y s te m p ip in g la y o u t, p ro c e s s , a n d m e c h a n ic a l d e s ig n 1 0 .S y s te m o p e ra tin g lo g ic T o a n s w e r th e s e q u e s tio n s a n d se t th e s e v a ria b le s , th e d e s ig n e r c a n u s e jo b s p e c ific te s tin g , h is to ric a l te s t d a ta , fie ld p e rfo rm an ce d a ta , in d u stry a v a ila b le m o d e lin g te c h n iq u e s , o r p ro p rie ta ry m o d e lin g te c h n iq u e s . The r e a l i t y is u s u a l l y a c o m b i n a t i o n o f s e v e r a l o f t h e a b o v e . B u rn e r ty p e s are v a rie d . E x a m p le s o f b u rn e rs c u rre n tly u s e d in th e in d u s try in c lu d e d rille d p ip e c a p s, d rille d h o riz o n ta l p ip e s e c tio n s, s a n d c a stin g s, i n v e s t m e n t c a s t i n g s , e tc . B u rn e rs a re ty p ic a lly d e s ig n e d a n d s u ite d fo r a d e fin e d r a n g e o f fla re g a s c o m p o s itio n s a n d p re s s u re s . O v e r a p e rio d o f tim e , th e s e n e w e r s ta g e d fla re s y s te m s h a v e e v o lv e d fro m u n its w ith ru p tu re d isc s a n d h ig h a v a ila b le in le t p re s s u re s a n d a fe n c e o n ly at th e m a n ifo ld , to s y s te m s w ith m u c h lo w e r p re s s u re s , ru p tu re p in v a lv e s , a n d f e n c e s e n c lo s in g th e c o m p le te f la re s y s te m . m u ltip o in t a p p lic a tio n s g round in th e fla re s has e v o lv e d p ro d u c tio n in d u stry T h e u s e a n d a p p lic a tio n o f a fro m to p rim a rily a p p lic a tio n s h ig h in p ressu re re fin in g and c h e m ic a l p la n ts w ith m u c h lo w e r p re s s u re s a n d e v e n in a p p lic a tio n s fo r L N G p la n ts w ith c ry o g e n ic g ases. G e n e r a l M u l t ip o in t F l a r e S y s t e m D e s ig n C r it e r i a F o r a n y m u l t i p o i n t s t a g e d g r o u n d f l a r e s y s t e m , i t is c r i t i c a l t h e s y s t e m d e s ig n e r h a v e a g o o d u n d e rs ta n d in g o f th e fo llo w in g in fo rm a tio n : a. A n t i c i p a t e d f l a r e g a s f l o w s c e n a r i o s f o r t h e s y s t e m b. E s tim a te d f lo w ra te d u ra tio n s fo r th e s y s te m c. G a s c o m p o s itio n s a n d te m p e ra tu re s fo r o p e ra tin g c o n d itio n s. d. S m o k e le s s p e rfo rm a n c e r e q u ire m e n ts e. R a d i a t i o n c o n s t r a i n t s f. F la m e h e ig h t o r fe n c e h e ig h t c o n s tra in ts g. F l a m e v i s i b i l i t y c o n s t r a i n t s h. N o is e c o n s tra in ts i. M a in te n a n c e a c c e ss re q u ire m e n ts A l l o f t h e s e a r e m a j o r f a c t o r s t h a t i n f l u e n c e t h e e n g i n e e r 's d e c i s i o n s w h e n d e s ig n in g th e fla re s y s te m . 5 Z eeco Inc. AFRC-JFRC October 2007 M a n y m u ltip o in t g r o u n d fla re s y s te m s a re d e s ig n e d to h a n d le a w id e r a n g e o f fla re g a s c o m p o s itio n s a n d te m p e ra tu re s . m u s t ta k e in to p ressu re a c c o u n t b o th th e h ig h e s t v o lu m e tric flo w d rop, a n d p e rfo rm an ce T h e fin a l d e s ig n o f th e s y s te m fo r th e a ls o m u s t c o n s id e r th e h e a t re le a se h ig h e s t m o le c u la r w e ig h t flo w c o n d itio n and th e fo r fla m e c o n d itio n s . The d e s ig n e r m u s t re v ie w th e p e rfo rm a n c e o f e a c h b u rn e r ru n n e r s e p a ra te ly fro m th e p e r f o r m a n c e o f th e to ta l s y s te m . In th e d e s ig n fo r m o s t o f th e s e m u ltip o in t fla re s y s te m s , th e re a re ty p ic a lly f lo w c a s e s th a t m a y b e v a s tly d iffe re n t fro m th e m a x im u m v o lu m e o r h e a t r e le a s e th a t m a y c o n s tra in th e d e s ig n . It is lik e ly th e d e s ig n a r r a n g e m e n t fo r s m o k e le s s b u r n in g o f th e h e a v ie s t g a s e s o r th e g a s e s th a t a re m o s t d iffic u lt to b u rn w ith o u t sm o k e , m a y n o t b e t h e c o r r e c t a r r a n g e m e n t t o e n s u r e t h e b u r n e r s c r o s s l i g h t i n s till c o n d itio n s fo r th e lig h te s t g a s th a t c a n b e fla re d . A ll o f th e c o n s tra in ts fo r th e s y s te m m u s t b e r e v ie w e d a n d c o n s id e r e d in th e fin a l d e s ig n . S p e c if ic S y s t e m R e q u i r e m e n t s T h e b a s ic p r o c e s s c o n d itio n s fo r th e o le fin p la n t fla re s y s te m (s ) in v o lv e d th is te s tin g a re a s d e fin e d b e lo w : M A IN F L A R E LP FLARE TANK FLARE T o ta l F lo w in M e tric 1 ,1 8 0 .8 1 .5 1 9 1 .8 8 3 2 7 .9 5 1 .0 7 28 5 70 48 E th y le n e BTX N itro g e n 1 1 .3 6 2 .5 6 4 .2 6 Tons per H our M o le c u la r W e ig h t T e m p e ra tu re (D e g C ) P rim a ry C o m p o n e n t M a x . In le t P re s s u re (p sig ) T h e F l a r e S y s t e m t h a t i s t h e f o c u s o f t h i s p a p e r o n t e s t i n g is t h e M A I N f l a r e s y s te m o n ly . In a d d itio n to th e fla r in g c a s e d e fin e d a b o v e , th e M A I N fla re w a s r e q u ir e d to fla re s e v e ra l o th e r g a s c o m p o s itio n s , in c lu d in g 1 0 0 % p ro p a n e , a ty p ic a l c ra c k e d g a s c o m p o s itio n , a n d a 1 0 0 % n a tu ra l g a s c o m p o s itio n . 6 The Z eeco Inc. AFRC-JFRC October 2007 m a jo r s y s te m d e s ig n c o n s tr a in ts th a t Z e e c o h a d to c o n s id e r a n d a d h e re to w e re as fo llo w s : 1. M a x i m u m i n l e t p r e s s u r e o f 1 1 .3 6 p s i g ( 0 .8 k g / c m 2 ) . 2 . M a x i m u m i n l e t p r e s s u r e is t o b e u s e d f o r R u p t u r e P i n V a l v e S e t t i n g 3. F u l l e n c l o s u r e ( r a d i a t i o n ) f e n c e a r o u n d s y s t e m 4. N o n -v isib le fla m e s fro m p e rs o n n e l o u tsid e th e fe n c e at g rad e. 5. F e n c e h e i g h t e q u a l t o m a x i m u m fla m e h e ig h t p lu s 2 0 % o f fla m e le n g th 6. R i n g l e m a n 0 .0 s m o k e d e n s i t y a t t h e t o p o f t h e f e n c e . 7. N o is e re s tric tio n o u tsid e th e fe n c e fo r th e m a x im u m flo w c o n d itio n The m a jo r s y s te m c o n s tra in ts lis te d above are d iffic u lt c o n s id e rin g th e d e s ig n f o r a m u ltip o in t g r o u n d fla re ones, s y s te m . w hen W hen c o n s id e re d in d iv id u a lly : • T h e m a x i m u m i n l e t p r e s s u r e t o b e u s e d f o r t h e s y s t e m d e s i g n is t h e s a m e as th e ru p tu re p in se t p re s s u re . T h is is s o m e w h a t d iffe re n t fro m t h e d e s i g n c r i t e r i a t h a t is t y p i c a l l y a p p l i e d . F o r m o s t s y s te m s , th e ru p tu r e p in se t p re s s u re c a n b e s lig h tly h ig h e r th a n th e m a x im u m in le t p ressu re fo r c o n d itio n s . th e fla re s y s te m under m a x im u m fla re gas flo w U n d e r c o n d itio n s w h e re th e ru p tu re p in v a lv e w o u ld o p e n , th e fla re g as flo w m a x im u m f lo w c o n d itio n . w o u ld ty p ic a lly b e m uch le ss th a n th e T h e re fo re , th e p re s s u re d ro p in th e c u s t o m e r 's i n l e t f l a r e h e a d e r s y s t e m p i p i n g w o u l d b e l e s s t h a n t h a t u s e d b y th e d e s ig n e r in s e ttin g th e m a x im u m a llo w a b le fla re p re s s u re a t th e fla re s y s te m in le t u n d e r m a x im u m f lo w c o n d itio n s . R u p tu re p in v a lv e s a re ty p ic a lly se t to o p e n a t p re s s u re s 5 to 1 0 % h ig h e r th a n th e d e fin e d m a x im u m in le t p re ssu re . F o r th is s p e c ific s y s te m , th e c u s t o m e r s e t t h e r u p t u r e p i n s e t t i n g a t 0 .8 0 k g / c m 2 . • M o s t s ta g e d fla re s y s te m s h a v e b e e n d e s ig n e d in th e p a s t to o p e ra te at o r n e a r s o n ic v e lo c ity a t th e b u rn e r. T h e m a jo rity o f th e s y s te m s in s e r v i c e h a v e o p e r a t i n g p r e s s u r e s r a n g i n g f r o m 15 t o 3 0 p s i g . s o n ic v e lo c ity of E th y le n e a p p r o x i m a t e l y 12 p s i g . at th e d e fin e d 5 C The te m p e ra tu re is F o r th is s y s te m , th e m a x im u m p o s s ib le b u r n e r p r e s s u r e , c o n s i d e r i n g s y s t e m p i p i n g p r e s s u r e d r o p s , is 1 0 .2 p s ig . T h is m e a n s u n d e r A L L o p e ra tin g c o n d itio n s , th e g a s f lo w a t th e b u r n e r tip w ill b e s u b -s o n ic . • M ost fla re p erfo rm an ce. 7 s y s te m s a re d e s ig n e d fo r R in g le m a n 1 .0 sm o k e le ss T h is d e fin itio n fo r s m o k e le s s p e rfo rm a n c e a llo w s fo r Z eeco Inc. th e AFRC-JFRC October 2007 u n c e rta in tie s of a ran g e of e n v iro n m e n ta l c o n d itio n s , and u n k n o w n s th a t c o u ld in flu e n c e th e fla re s y s te m s a c tu a l p e r f o r m a n c e in t h e f ie l d . F o r t h e s y s t e m d i s c u s s e d i n t h i s p a p e r , t h e c u s t o m e r 's r e q u i r e m e n t w a s R i n g l e m a n 0 .0 a t t h e t o p o f t h e f e n c e . • T h e e n c l o s u r e f e n c e a l l o w s f o r s o m e c o n t r o l o f t h e w i n d , h o w e v e r , it a ls o lim its th e a v a ila b le a ir fo r c o m b u s tio n . C F D m o d e l i n g is u s e d t o e n s u re th e p r o p e r b u r n e r r o w sp a c in g . • A llo w a b le n o is e le v e ls o u ts id e th e fe n c e w e re to b e lim ite d to 85 d b a fo r s u s ta in e d c a se s a n d 89 d b a fo r m a x im u m f lo w c a se s. T h is w a s a m a jo r fa c to r fo r th e d rillin g p a tte rn u se d . T e s t in g f o r M id d l e E a s t P r o j e c t T h e p r im a ry g o a l o f th e te s tin g fo r th is p ro je c t w a s to d e m o n s tra te th e p e rf o r m a n c e o f th e m u ltip o in t g r o u n d fla re s y s te m b u r n e r s o p e ra tin g u n d e r c o n d itio n s th a t c lo s e ly s im u la te d th e a n tic ip a te d fie ld c o n d itio n s . T h e fin a l te s ts w e r e to b e w itn e s s e d b y th e c u s to m e r. A s p e c ific te s tin g p r o c e d u r e w a s p r e p a r e d a n d is s u e d to th e c u s to m e r. A fte r r e v ie w a n d c o m m e n ts b y th e c u s to m e r a n d a ls o b y th e e n d u s e r, a fin a l t e s t i n g p r o c e d u r e w a s a g r e e d t o b y a ll p a r t i e s . F o r th is p a rtic u la r s y s te m , tw o (2 ) d iffe re n t d rillin g p a tte rn s a re u s e d in th e s y s te m . T h e p r i m a r y d i f f e r e n c e is t h e t o t a l h e a t r e l e a s e f o r t h e l a r g e r f l o w a r e a b u r n e r is a p p r o x i m a t e l y 5 0 % h i g h e r t h a n t h e h e a t r e l e a s e f o r t h e s m a l l e r flo w a re a b u rn er. T h e la r g e r h e a t r e le a s e b u r n e r tip w a s u s e d f o r th e te s tin g to e n s u re s m o k e le s s p e rfo rm a n c e . T h e s m a lle r h e a t r e le a s e b u r n e r tip w a s u s e d fo r th e te s tin g to e n s u re c ro s s lig h tin g o f th e b u rn e rs . F o r t h i s p a r t i c u l a r c u s t o m e r 's a p p l i c a t i o n , t h e i n i t i a l d e c i s i o n s i n v o l v e d t h e s e le c tio n o f a b u rn e r, a n d th e a n tic ip a te d h e a t re le a s e p e r b u r n e r th a t w a s p o s s ib le . A p r e lim in a ry b u r n e r h e a t r e le a s e w a s s e le c te d a n d a p p lie d . The te s tin g p r o g ra m c o n s is te d o f te s tin g a s in g le b u r n e r o n th e r a n g e o f g a s e s d e fin e d b y th e c u s to m e r, a n d th e n te s tin g o f a g ro u p o f th re e (3 ) b u rn e rs . TEST GASES: E th y le n e (fo r sm o k e le ss p e rfo rm a n c e ) T u ls a N a tu ra l G a s (fo r c ro s s lig h tin g ) TEST PRESSURES: 8 M a x im u m : 1 1 .3 6 p s i g M in im u m : 2 .8 p s i g AFRC-JFRC October 2007 Z eeco Inc. TEST ARRA N G EM EN TS: S in g le B u r n e r T ip T h re e (3 ) B u r n e r T ip s T h e g e n e r a l a r r a n g e m e n t o f t h e e q u i p m e n t f o r t h e t e s t i n g is p e r F i g u r e 5, F la re T e st A re a P F D . E th y le n e w a s p u r c h a s e d fro m a c o m m e rc ia l s u p p lie r in a h ig h p r e s s u r e tu b e tra ile r. T h e c o m p o s itio n o f th e e th y le n e fo r th e te s t w a s c o n firm e d to b e 9 9 .6 % e th y le n e , 0 .3 % e th a n e , w ith th e r e m a in in g b e in g C O 2 a n d m e th a n e . T h e e th y le n e tu b e tra ile r w a s u s e d to p re s s u riz e th e la r g e 3 0 ,0 0 0 g a llo n m ix i n g ta n k . F I G U R E 5: T est A rea P F D T h e b u r n e r o r b u r n e r s w e r e s e t u p o n a h o r iz o n ta l 6 in c h p ip e p ig . F i g u r e 6. T h e f lo w to th e b u rn e rs w a s c o n tro lle d u s in g a v a lv e o n th e o u tle t o f th e 3 0 ,0 0 0 g a llo n m ix ta n k . o p e ra to r. See T h e p r e s s u r e is c o n t r o l l e d m a n u a l l y , b y t h e E a c h o f th e te s t p o in ts w a s ru n fo r 2 -3 m in u te s. T h e o p e ra to r h a s a d ire c t re a d o u t o f th e p re s s u re a t th e b u r n e r tip d u rin g th e te s t ru n . The f l a r e g a s f l o w s t o t h e b u r n e r p i g t h r o u g h a n o m i n a l 18 i n c h d i a m e t e r p i p e lin e . I n d iv id u a l b u r n e r s a re in s ta lle d w ith fu ll p o r t b a ll v a lv e s to a llo w fo r e a s y o p e ra to r m o d if ic a tio n o f th e n u m b e r o f b u r n e r s in s e rv ic e d u rin g th e te s tin g . In a d d itio n , th e b u r n e r s a re p ip e d to a llo w fo r m o d if y in g th e b u r n e r to b u r n e r s p a c in g d u rin g th e te s tin g to e v a lu a te fla m e s p a c in g fo r fla m e in te rfe re n c e a n d fo r c ro s s lig h tin g . 9 Z eeco Inc. AFRC-JFRC October 2007 T h e p ig h a s a s in g le p ilo t b u rn e r. T h e p i l o t b u r n e r is f i r e d u s i n g n a t u r a l g a s . T h e p i l o t is i g n i t e d u s i n g a d i r e c t s p a r k H E I e l e c t r o n i c i g n i t i o n s y s t e m . F I G U R E 6 :________F l a r e B u r n e r T e s t P i g T h e t e m p e r a t u r e o f t h e f l a r e g a s is c o n t r o l l e d u s i n g t h e h e a t t r a c i n g t h a t is a v a ila b le o n th e m ix ta n k . T h e m ix ta n k is fu lly h e a t tra c e d a n d in su la te d . T h e h e a t t r a c i n g t h a t is i n s t a l l e d is c a p a b l e o f h e a t i n g t h e t a n k t o a m a x i m u m te m p e ra tu re o f a p p ro x im a te ly 6 0 0 F. T h e re q u ire d te m p e ra tu re c a n b e set o n t h e c o n t r o l l e r t h a t is m o u n t e d l o c a l t o t h e t a n k . D u r in g th e te s tin g , th e f o llo w in g m e a s u r e m e n ts w e re ta k e n a n d re c o r d e d fo r e a c h o f t h e t e s t p o i n ts : ■ V i d e o w a s t a k e n a t 9 0 d e g r e e s a n d 0 d e g r e e s t o t h e t e s t p ig . V id e o ta k e n at 0 d e g re e s w a s ta k e n fro m g rad e . d e g re e s w a s ta k e n fro m c e n te r-p o in t. V id e o at 90 a n e le v a te d lo c a tio n n e a r th e fla m e D u rin g th e v id e o , th e v id e o c a m e ra o p e ra to rs w e r e in c o n ta c t w ith th e p e rs o n n e l m e a s u r in g th e fla re g a s 10 Z eeco Inc. AFRC-JFRC October 2007 p re s s u re a n d te m p e ra tu re . v e rb a lly o n th e v id e o T h e fla re g a s p r e s s u r e w a s r e c o r d e d c a m e ra s b y th e o p e ra to rs d u rin g th e film in g to b e tte r fa c ilita te fla m e p e rfo rm a n c e . ■ S till p i c t u r e s w e r e t a k e n a t v a r i o u s p o i n t s a r o u n d t h e f l a r e t e s t p ig , in a d d itio n to b e in g ta k e n a t th e s a m e lo c a tio n s as th e v id e o cam eras. ■ N o ise w as m easu red at 50 feet and 100 feet d ista n c e feet d ista n c e p e r p e n d ic u la r to th e te s t p ig . ■ R a d ia tio n w as m easu red at 50 feet and 100 p e r p e n d ic u la r to th e te s t p ig . ■ F la re b u r n e r tip g a s p re s s u re w a s m e a s u r e d a n d re c o r d e d e v e ry 15 s e c o n d s d u r i n g e a c h t e s t r u n . ■ F la re b u r n e r tip g a s te m p e r a tu r e w a s m e a s u r e d a n d r e c o r d e d e v e r y 15 s e c o n d s d u r i n g e a c h t e s t r u n . ■ R in g le m a n n u m b e r w a s e s tim a te d a n d r e c o r d e d b y tw o s e p a ra te o b s e rv e r s lo c a te d a t 0 a n d 9 0 d e g re e s to th e fla re te s t p ig . T h is w a s th e n c o n firm e d b y re v ie w in g th e v id e o a fte r te s tin g w a s c o n c lu d e d . T e s tin g w a s p e r f o r m e d o n a s in g le b u r n e r tip to d e te rm in e th e p re s s u re r a n g e (d e s ta g e p re s s u re ) th a t c o u ld b e a p p lie d a n d e n s u re s m o k e le s s b u rn in g . The b u r n e r w a s t e s t e d a n d a d e s t a g e p r e s s u r e o f a p p r o x i m a t e l y 2 .7 5 p s i g w a s d e te rm in e d to b e s u i t a b l e t o a c h i e v e R i n g l e m a n 0 .0 o n e t h y l e n e g a s e s . T e s tin g w a s a ls o p e rf o r m e d o n th e h ig h e r m o le c u la r w e ig h t g a s e s th a t a p p ly to th is s a m e fla re s y s te m , to e n s u re th e s m o k e le s s p e rf o r m a n c e o f th e b u r n e r w o u ld b e m a in ta in e d fo r th e s e h ig h e r h e a t re le a se ca se s. T h e h ig h e r h e a t r e le a s e c a s e s f o r th is s a m e fla re a re s a tu ra te s , a n d th e p e rf o r m a n c e w a s c o n firm e d . T h e o rig in a l d rillin g p a tte rn th a t w a s s u ita b le to a c h ie v e th e s m o k e le s s p e rfo rm a n c e o f th e b u rn e r o n b o th E th y le n e a n d o n th e h e a v ie r m o le c u la r w e ig h t g a s c a s e s w a s fo u n d , h o w e v e r , n o t b e s u ita b le to a c h ie v e th e r e q u ir e d p e rfo rm a n c e fo r n o ise . T h e b u r n e r d rillin g p a tte rn w a s th e n m o d ifie d s e v e ra l tim e s to f in d a fin a l d rillin g p a tte rn th a t m e t b o th th e re q u ir e m e n ts fo r s m o k e le s s b u rn in g a n d fo r n o ise . T e s tin g th e n to o k p la c e o n th re e (3 ) b u rn e rs . te s tin g w as to fin a liz e th e sp a c in g o f th e b u r n e r tip s , f o r fla re in te rfe re n c e , a n d a ls o fo r c ro s s lig h tin g . w a s e n s u re d u s in g n a tu ra l g as. 11 T h e p r im a r y p u r p o s e o f th is fla m e T h e c ro s s lig h tin g o f th e b u rn e rs T h is s p a c in g w a s th e n te s te d to e n s u re th e re AFRC-JFRC October 2007 Z eeco Inc. w a s n o c h a n g e in th e fla re fla m e o v e ra ll h e ig h t a n d s m o k e le s s p e rf o r m a n c e d u r in g th e fla r in g o f b o th th e e th y le n e fla re g a s c a s e a n d a ls o th e h e a v ie r s a tu ra te d g a s case. T e s tin g w a s p e rf o r m e d in v a rio u s w in d c o n d itio n s . F la m e le n g th a n d c ro s s lig h tin g a re m o s t c ritic a l in v e ry lo w w in d c o n d itio n s . s y s t e m s , s m o k e l e s s p e r f o r m a n c e is g r e a t l y i n f l u e n c e d b y t h e w i n d . p a rtic u la r b u rn er s y s te m and fo r th e gases p e rf o r m a n c e w a s m o s t d iffic u lt to a c h ie v e . d e fin e d , th e F o r m ost F o r th is sm o k e le ss C ro s s lig h tin g in lo w w in d c o n d itio n s o n lig h t g a s w a s s u c c e s s fu l a n d c o n firm e d . M a x im u m fla m e le n g th d u r in g th e te s tin g w a s d e te r m in e d to b e 3 5 fe e t. R esults T h e e n d re s u lts o f th e te s tin g w a s th e d e v e lo p m e n t o f a b u r n e r tip a s s e m b ly th a t c o u ld a c h ie v e th e s m o k e le s s b u rn in g r e q u ire d b y th e c u s to m e r fo r th e w i d e r a n g e o f g a s e s f o r t h e f l a r e s y s t e m , w h i l e s till m e e t i n g t h e n o i s e l e v e l a n d fla m e h e ig h t c o n s tra in ts . T h e fin a l b u r n e r la y o u t in th e fla re fie ld w a s c o n f ir m e d u s in g C F D m o d e lin g f o r a ir a c c e s s a n d f la m e le n g th . F ig u re s 7 a n d 8 s h o w te s tin g o f th e fin a l b u r n e r d e s ig n a t th e m a x im u m te s t p re s s u re o f 0 .8 0 k g / c m 2 . F I G U R E 7 :________S i n g l e B u r n e r T i p T e s t i n g 12 Z eeco Inc. 13 AFRC-JFRC October 2007