FI91558C

FI91558C - Pulse Combustion Boiler

Info

Publication number: FI91558C
Application number: FI925507A
Authority: FI
Inventors: Markku Orjala; Veli-Pekka Heiskanen; Carvalho Jr Joao Andrade De; Marco Aurelio Ferreira; Claudio Bressan
Original assignee: Valtion Teknillinen; Inst Nacional De Pesquisas Esp
Priority date: 1992-12-04
Filing date: 1992-12-04
Publication date: 1994-07-11
Also published as: BR9307583A; WO1994014002A1; FI91558B; EP0670984A1; FI925507A0

Description

PULSSIPOLTTOKATTILA 91 558PULSE COMBUSTION BOILER 91 558

Keksinnon kohteena on pulssipolttokattila, johon kuuluu oleelli-sesti pystysuora polttoputki, tasauskammio sen alapååsså, arina 5 polttoputken alaosassa, polttoaineen syottolaitteet polttoaineen syottåmiseksi arinalle, palamisilman syottolaitteet ja yksi tai useampi låmmonsiirtopinta kattilan tuottaman låmmon talteenotta-miseksi.The invention relates to a pulsed combustion boiler comprising a substantially vertical combustion pipe, a compensating chamber at its lower end, a grate 5 at the bottom of the combustion pipe, fuel supply devices for supplying fuel to the grate, combustion air supply devices and one or more heat transfer boiler heat transfer surfaces.

10 Johdannossa mainittua tyyppiå oleva pulssipolttokattila on esitelty kongressijulkaisussa ENCIT 90 VOL II, Itapema 10.-12.12.1990, ss. 761 - 766; Ferreira et al. Pulssipolttokattilan etuina voidaan mainita erittåin korkea arinarasitus ( 4,2 - 5,1 MW/m2 ) ja pieni ilmaylimåårå, jotka molemmat edut johtuvat 15 pååasiassa akustisten våråhtelyjen aineen- ja låmmonsiirtoa sekå kaasujen sekoittumista tehostavasta vaikutuksesta. Pulssipoltto-menetelmållå on vielå myos muita etuja. Tåmå kattilatyyppi soveltuu erinomaisesti kiinteålle polttoaineelle.10 A pulsed combustion boiler of the type mentioned in the introduction is presented in the congress publication ENCIT 90 VOL II, Itapema 10-12.12.1990, p. 761 - 766; Ferreira et al. The advantages of a pulsed combustion boiler include a very high grate load (4.2 - 5.1 MW / m2) and a small excess of air, both of which are mainly due to the effect of the acoustic oscillations on the mass and heat transfer and the mixing of gases. The pulse combustion method also has other advantages. This type of boiler is ideally suited for solid fuel.

20 Alkuperåisesså Rijke-tyyppisesså pulssipolttokattilassa kåyte-tåån polttoputken alapååsså tasauskanuniota, jonka kautta syotetåån myos ilma polttoputkeen. Tåmån tyyppinen kanavarakenne aiheuttaa luonnostaan våråhtelevån liekkirintaman, jonka taajuus on tyypillisesti 50 - 100 Hz. Arina on sijoitettu polttoputken 25 alaosaan ja polttoainetta syotetåån arinan ylåpuolelle sijoite-tusta yhteestå. Huolimatta tehokkaasta sekoittumisesta savu-kaasujen mukana poistuu myos palamatonta materiaalia, mikå heikentåå kattilan hyotysuhdetta.20 In the original Rijke-type pulsed combustion boiler, a compensating cannon is used at the lower end of the combustion pipe, through which air is also fed into the combustion pipe. This type of duct structure naturally causes an oscillating flame front, the frequency of which is typically 50 to 100 Hz. The grate is located at the bottom of the combustion pipe 25 and fuel is fed from a joint located above the grate. Despite the efficient mixing with the flue gases, non-combustible material is also removed, which impairs the efficiency of the boiler.

30 Tåmån keksinndn tarkoituksena on parantaa nykyisten pulssipolt-tokattiloiden hyotysuhdetta. Keksinnon mukaisen kattilan tunnus-merkit on esitetty oheisissa patenttivaatimuksissa. Keksinto pohjautuu paljolti siihen havaintoon, ettå polttoputken ylåpåå-hån voidaan myos jårjeståå tasauskammio mahdollisine låmpopin-35 toineen, josta savukaasuvirta ohjataan erottimeen kiinteiden palamattomien hiukkasten erottamiseksi ja palauttamiseksi sopivaa palautuslinjaa pitkin takaisin polttoputkeen. Tållaisen jårjestelyn aiheuttamien painehåvioiden ei ole todettu håiritse-vån polton pulssittumista. Kattilan hyotysuhde saadaan sangen 40 hyvåksi ja normaali tuhka voidaan tarvittaessa erottaa erilli- 91558 2 sellå kiertoerottimen jålkeiseen savukaasulinjaan liitettåvållå savukaasupuhdistimella, esim. multisyklonilla, erityisesti lentotuhkan erottamiseksi.The object of the present invention is to improve the efficiency of existing pulse combustion boilers. The characteristics of the boiler according to the invention are set out in the appended claims. The invention is largely based on the finding that a compensating chamber can also be arranged at the top of the combustion pipe with possible heat-35 means from which the flue gas stream is directed to the separator to separate and return solid unburned particles back to the combustion line. The pressure losses caused by such an arrangement have not been found to interfere with the pulsation of combustion. The boiler efficiency is quite good and the normal ash can be separated, if necessary, with a separate flue gas cleaner, e.g. a multicyclone, connected to the flue gas line after the circulating separator, in particular to separate the fly ash.

5 Muut keksinnon edut ja sovellutusmuodot selviåvåt jåljempånå esitetystå sovellutusesimerkistå.Other advantages and embodiments of the invention will become apparent from the application example presented below.

Seuraavassa keksintoå kuvataan viittaamalla oheiseen kuvaan, joka esittåå eråstå keksinnon mukaista kiertopulssipolttokat-10 tilaa. Tunnetun tekniikan mukaisesti keksinnon mukaiseen pulssipolttokattilaan kuuluu ensinnåkin polttoputki 1, tasaus-kammio tåmån alapååsså, polttoaineen syottolaitteet 12, 13 ja 14, arina ja ilmansyottolaitteet 21 ja 25. Nåiden lisåksi palamattomien hiukkasten kierråttåraiseksi tåhån kattilaan kuuluu 15 ylempi tasauskammio 3, tåhån kanavalla 24 yhdistetty syklonin muodostama erotin 15 ja tåstå palamattomat hiukkaset takaisin polttoputkeen johtava paluulinja 19.The invention will now be described with reference to the accompanying figure, which shows a state of rotary pulse burners-10 according to the invention. According to the prior art, the pulse combustion boiler according to the invention firstly comprises a combustion pipe 1, a leveling chamber at the lower end thereof, fuel supply devices 12, 13 and 14, a grate and air supply devices 21 and 25. formed by the separator 15 and the return line 19 leading to the non-combustible particles back to the combustion tube.

Polttoputki 1 on tåsså vuorattu vesivaipalla 4, joka kåsittåå 20 veden sisåån- ja ulosottoyhteet 5 ja 6. Matalalåmpoarvoisia polttoaineita poltettaessa polttoputki voidaan yinpåroidå muurauksella. Polttoaine kaadetaan siiloon 11, joka johtaa putkeen 12, josta syottolaite 13 annostelee polttoainetta johdettavaksi putken 14 kautta polttoputkeen arinan 7 ylåpuolel-25 le. Arinan 7 muodostaa rei'itetty taso ja sen påållå kåytetåån lisåksi sekoitussiipiå 8, joita pyoritetåån tasauskammioon 2 asennetulla moottorilla 9. Moottorin suojana kåytetåån kartiota 10. Luonnollisesti moottori voidaan sijoittaan tnuuallekin. Puhallin 25 tyontåå ilmaa kanavan 21 kautta tasauskammioon 2, 30 jonka kautta ilma johdetaan polttoputkeen 1.The combustion pipe 1 is here lined with a water jacket 4, which comprises 20 water inlet and outlet connections 5 and 6. When burning low-calorific fuels, the combustion pipe can be annealed by masonry. The fuel is poured into a silo 11 leading to a pipe 12, from which the feeder 13 dispenses the fuel to be led through the pipe 14 to the combustion pipe above the grate 7. The grate 7 is formed by a perforated plane and on it are additionally driven mixing vanes 8, which are rotated by a motor 9 mounted in the equalization chamber 2. A cone 10 is used to protect the motor. The fan 25 pushes air through the duct 21 into the equalization chamber 2, 30 through which the air is led to the combustion pipe 1.

Ylempåån tasauskammioon 3 asennetaan edullisesti låmpopintoja 23, joiden avulla kattilan tuottama låmpo voidaan johtaa ulos yhdesså mahdollisen polttoputken 1 vesivaippaan 4 siirtyneen 35 låmmon kanssa. Tasauskammiosta 3 johtaa kanava 24, joka muodostaa pienen painehåvidn olosuhteiden stabilisoimiseksi tasauskammioiden 2 ja 3 sekå polttoputken 1 muodostamassa jårjestelmåsså sekå virtausnopeuden kasvattamiseksi hiukkasia johdettaessa sykloniin 15.In the upper equalization chamber 3, heating surfaces 23 are preferably installed, by means of which the heat generated by the boiler can be led out together with the heat 35 transferred to the water jacket 4 of the possible combustion pipe 1. A channel 24 leads from the equalization chamber 3, which forms a small pressure drop in order to stabilize the conditions in the system formed by the equalization chambers 2 and 3 as well as in the combustion tube 1 and to increase the flow rate when introducing particles into the cyclone 15.

IIII

Claims

A pulse combustion boiler, which comprises substantially a vertical combustion tube (1), equalizer chamber (2) in its lower breath, a grate (7) in the lower portion of the combustion tube (1), the fuel supply means (12, 13, 14) for feeding the fuel to the grate (7), combustion air supply means (21, 25) and one or more heat transfer surfaces (23) for recovering the heat produced by the boiler, characterized in that the boiler comprises an upper leveling chamber (3) in the upper spirit of the combustion tube. (1) and then in the flow direction, a separator (15) for separating unburnable particles and the spring connection (16) is joined to the return line (19) to the combustion tube (1) above the grate (7) for burning the unburned fraction and thereby reducing the losses. 5 91558

2. Pulse combustion boiler according to claim 1, characterized in that the combustion pipe (1) is cut throughout the year.

Pulse combustion boiler according to claim 1, characterized in that the separator (15) is a cyclone.

4. Pulse combustion boiler according to claim 1, characterized in that the return line (19) of the separator (15) comprises an auxiliary separator (20) for appropriate sampling and / or removal of circulating material.

5. Pulse combustion boiler according to any one of claims 1-4, characterized in that at least one heat transfer surface (23) is positioned in the upper leveling chamber (3).

Pulse combustion boiler according to any one of claims 1-5, characterized in that it comprises rotatable mixing blades (8) on top of the grate (7). 20

7. Pulse combustion boiler according to one of claims 1-6, characterized in that there is a wall on the inner surface of the combustion pipe.

Pulse combustion boiler according to any one of claims 1-6, characterized in that a cooling jacket (4) is provided around the combustion pipe (1).

A pulse combustion boiler according to any one of claims 1-4, characterized in that an intermediate chamber provided with a heat transfer surface is located between the upper leveling chamber and the separator.

Pulse combustion boiler according to any one of claims 1-4, characterized in that after the circulation separator (15) the flue gas line comprises an ash separator, e.g. a cyclone for removing solid particles from the flue gases.