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Show ■f T E X A C O Houston, Texas Nov e m b e r 12, 1980 3 NOTES ON THE AM ER I C A N FLAME RESEARCH C O M M I T T E E I N T E R NA TI O NA L SYMPOSIUM ON I N DU STRIAL PROCESS C O M B U S T I O N T E CH NOLOGY N E W P O R T BEACH, C A L I F O R N I A O C T O B E R 2 7 AND 28, 1980 ___________ M E M O R A N D U M TO FILE T h e r e w e r e 74 registrants, 8 technical papers and a visit to the K V B I n c o r p o r a t e d m a n u f a c t u r i n g facilities. The pa pers pr es e n t e d w e r e topical and germ an e for current industrial applications. P r oc e e d i n g s are attached. T h e visit to KVB was very enlightening, p a r t i cu la r ly in regard to the d e v e l o p m e n t of a sonic soot blowe r as an en ergy saving device. An index of the papers (IC No. 184843) is attached. B e l o w are se le ct e d o bs er v a t i o n s by this writer. 1) J. G. Witkampt, Foundation. International Flame Research It is always interesting to find papers whe r ei n the res ea rc h er has deve l op ed c or re lations to bring t og ether a w i d e scattering of data. This is very us eful in the design of equipment. IFRF p r e s en te d on their Figur e 9, a corre l at io n of NOX Em i ssion w i t h co m bustion intensity, heat ex tr a ct io n and flame confinement. The NOX make is pro p or ti on a l to hea t re le a s e d by the burner, inversely p r o p o r tional to its flame volume and b ox e f f ic ie nc y and also inversely p r o p or ti on a l to the square root of the total gas inside the jet to the air plus fuel mass. The correla ti o n indicates that the NOX make changes m o s t d r a ma ti c al ly at the low firing rate, and that at high firing rates it tends to level off. This c o rr e la ti on w as not only for small burners, but included a 34 m eg awatt flame (160 million b t u/hr). It should be very useful to EDH in c omparing the N O X m a k e claimed by vendors. Memorandum 2) to File Y. Hirosse, - 2 - N ov e m b e r 12, 19 80 Nipp on Furnace T his paper reviews burners te c hn ol og y in Japan w h e r e NOX em is s io n limits are very stringently controlled. Many of the b urners cited have internal re circulation w i t h i n the setting; i.e., g ases just in front of the burners are recirculated through the burner block to the rear of the burner. T his probably results in a high ma i n t e n a n c e factor. Also, most of the data given were for relatively small burner. When these flames are cooled by the load, low NOX levels result. 3) W. H. Wheeler, Ur gu a rh ar t En gineering of London T his is an e x ce ll en t review of the basic kinetics involved in NOX production. It also given insight as to the b en efits to be derived, when using stage combustion for n it rogen containing fuels. The advantages of hot air plus staged co mb ustion for n i tr o g e n containing fuels was also indicated at the Comb us t io n Institute meeting held ear li er this year, at the University of Waterloo. Fuel nitrogen is c o nv er t ed to mole cu la r nitrogen in the first (fuel-rich) stage by using preheated air. But c are must be taken to'cool the flame in the oxid at io n second stage. This will require an opti mi z at io n on b u r no u t and NOX m ake within the radiant chamber. 4) R. J. Tidona, 5) Dr. A. Thedki, John Zink Company, and M i d l a nd Ross Corpo r at io n It is interesting to take these two papers together since each required a qas t emperature in the box in the or de r of 2500 to 2900 degrees F. In the former, small burners firing into a thermal reformer m o d u l e at John Zink's test heater showed very low N O X make, in the order of 40 to 50 parts per million. Thedki reported on a test unit for a reheat heater. He found high NOX make, in the order of 200-300 parts per million. Also contrary to the ex p e r i e n c e by others he found that reducing the oxygen concen t ra ti on did not reduce NOX. His invest ig at io n show no si gnificant reduction. In fact, a slight NOX increase when ox ygen w a s reduced. It was concl u de d that the d i f f e r e n c e in the two u nits was the rapid cooling of the primary flame in the reformer furnace and the long residence time in the reheat furnace. Memorandum to F i l e 5) - 3 - November 12, 1980 Visit to KVB Inc. m a n u f a c t u r i n g facilities. KVB is a su b si di ar y of R es earch C ot tr e ll Company. 5a) Sonic Soot Blower - KVB has license from a Swed i sh company, A Sonic Soot Blower. The b lo we r is a low frequency, high energy sonic device, op e r a t i n g at 250HZ at 145 decibels. The sound level is acc e pt ab le to O S H A since the external noise is inuted by a re fr ac to r y and insulation. Each horn costs $5,280 and is o p e r a b l e to 1900 F t emperature level. A spe c if ic at i on is attached. As of O c t o be r 31, 1980, horns have been or are being installed on seven steam boiler c o n ve c ti on sections firing oil (gravity not s p e c i f i e d ) , one firing crude oil, and and three firing u n s p e c i fied wa s te streams. Also two economizers, firing coal in the m a i n boiler, are specified. 5b) Co m b u s t i o n Gas An alysis - KVB also ma k es a c o m p l e t e l y automated carbon monoxide, o xy ge n and nitric oxi de analyzer, including a sampling system. The sampler is a fritted metal filter having 1.8 m i cr on pores. The filter o pe ra te s in three modes. Normal setting for hot gases sucked thru the filter and then flowing to the analyzer via heated teflon tubing. The second mode is w hen c a li br a ti ng gas are sent from the remote encl o su re up to but not including the sample filter and then via the heated teflon tubing to analyzer. This is a c al i br a t i o n of the entire unit. A n d lastly, cleaning of the filter o c cu rs by reverse blast of air. _ For m ost units, m i n i m u m excess o x ygen will result in m i n i m u m NOX; however, one must be c e r t ai n that burnout is complete. Under most conditions, the c arbon monox id e level will rise prior to smoke formation, thus m a i n t a i n i n g a low c a rb on mo no x i d e level, say less than 50 to 100 ppm, c o n si st e nt w ith m i n i m u m o xy ge n c o n c e n t r a t i o n needed for complete combustion, will provide o p t i m u m operation. JL m g g :3/13 Attachnu-nt (Copy #2 of Proce*•dings) |
