SE186642C1

SE186642C1 -

Info

Publication number: SE186642C1
Authority: SE
Publication date: 1963-01-01

Description

Uppfinnare: F Sehytil De kanda anordningarna for rostning av livsmedel, sasom kaffe, kakao, jordnotter, malt osv. kunna i stort sett indelas i fyra grupper. Vid de aldsta kfinda fOrfaringssatten uppvarmes materialet i roterande trummor. Uppvarmningen sker harvid antingen uteslutande indirekt eller genom att uppvarmd luft eller mot materialet inerta gaser bringas att passera detta. Vid dessa forfaringssatt fir det en nackdel, att uppvarmningstiden fir mycket lang, s. att uppkomsten av smaken forsamrande forruttningsprodukter ej fullstfindigt kan forhindras. Dessutom upptrfider till foljd av den langa behandlingstiden aven en stor viktforlust, varvid forlusten till en oproportionerligt stor del bestar av de substanser, vilka just aro mest vfirdefulla (eteriska olj or ). Inventors: F Sehytil The known devices for roasting food, such as coffee, cocoa, peanuts, malt, etc. can be broadly divided into four groups. In the oldest experimental kits, the material is heated in rotating drums. The heating takes place either exclusively indirectly or by passing heated air or gases inert to the material. In these procedures there is a disadvantage that the heating time is very long, so that the formation of the taste-decomposing decomposition products cannot be completely prevented. In addition, as a result of the long treatment time, a large weight loss also occurs, the loss to a disproportionately large part consisting of the substances which are just the most valuable (essential oils).

En annan rostningsmetod, som hittills endast bar anvants for rostning av kaffe, bestar dfiri, att vfirme tillfores medelst straining, sarskilt medelst infraroda stralar. Dk varmet vid denna metod alstras i materialet sjalvt, är det mycket svart eller till och med oraajligt att undvika bildandet av overhettade karnor. Det är i praktiken omojligt att erhalla en fullstandigt likformigt genomrostad produkt utan brannflackar, varfor sadana rostningsapparater vanligen salj as direkt kopplade med en kvarn, for att dolja denna fareteelse. Dessutom fir man tvungen att arbeta med elektriskt uppvarmda stralningsapparater. Da forhallandevis stora varmemangder aro erfor derliga for rostningen, kunna stora ekonomiskt arbetande aggregat icke konstrueras enligt denna metod. Another roasting method, which hitherto could only be used for roasting coffee, consists in the fact that vfirme is supplied by means of straining, in particular by means of infrared rays. Because the heat in this method is generated in the material itself, it is very black or even unreasonable to avoid the formation of overheated kernels. It is practically impossible to obtain a completely uniformly roasted product without fire flakes, which is why such roasting machines are usually sold directly connected to a mill, in order to hide this danger. In addition, fir had to work with electrically heated radiators. As relatively large amounts of heat are required for roasting, large economically efficient units cannot be constructed according to this method.

Vid en tredje grupp av rostningsanlaggningar, sarskilt for rostning av kaffe och kakao, anvandes den s. k. »fluidizedbethprocessen vid rostningen. Da denna badd vid detta forfaringssatt uppbygges pa en rost, kan omedelbar kontakt mellan materialet och roststavarna eller med en perforerad platta icke undvikas, sh att avenledes overhettning ar oundviklig, enar rostningstuften maste upphettas la.ngt Over rostningstemperaturen. Dessutom andras kaffebonornas specifika vikt under rostningsprocessen avsevart, sa att gastillforseln maste efterregleras under hela rostningsprocessen. Denna reglering medfor avsevarda driftssvarigheter. In a third group of roasting plants, especially for roasting coffee and cocoa, the so-called "fluidized bed" process was used in roasting. As this bath is built on a grate in this procedure, immediate contact between the material and the rust rods or with a perforated plate can not be avoided, so that overheating is inevitable, otherwise the roasting tuft must be heated far above the roasting temperature. In addition, the specific weight of the coffee beans during the roasting process is considerable, so that the gas supply must be post-regulated during the entire roasting process. This regulation entails considerable operating durations.

Vid den fjarde gruppen ay rostanlaggningar anvandas spjalverk, pa vilka det material, som skall behandlas, anbringas i skikt, genom vilka en varm luftstrom ledes nedifran och uppat. Sadana anlaggningar medfOra fordelen, att 8verhettning av materialet är fullstandigt utesluten, men nagon behandling vid forhallandevis hoga temperaturer ar icke mojlig, sâ att dessa anlaggningar praktiskt taget endast kunna anvandas som torkugnar for malt. Ytterligare en nackdel an det stora platsbehovet och det relativt daliga utbytet. In the fourth group of rusting systems, splitters are used, on which the material to be treated is applied in layers, through which a hot air stream is conducted from below and upwards. Such plants have the advantage that heating of the material is completely excluded, but no treatment at relatively high temperatures is possible, so that these plants can practically only be used as drying ovens for malt. Another disadvantage of the large need for space and the relatively poor exchange.

Foreliggande uppfinning avser en anordRing och ett forfaringssatt for rostning och nedkylning am kaffe, kakao, jordnotter, malt 2— — osv. vid vilka ovannamnda nackdelar undvikas och dessutom stora tekniska och ekonorniska fordelar uppnas. Uppfinningen at' baserad pa en avsevard andring av fluidizedbed-forfaringssattet. Den fluidiserade fasen uppratthalles i en reaktor, vars tvarsektion 8kar uppat och i vilken skillnaderna i materialets specifika vikt, vilka upptrada under rostningsprocessen, automatiskt kunna kompenseras. Darigenom, att reaktorns Oppningsvinkel är utbildad som hos ett venturimunstycke, kan materialet med ytterst liten kontaktyta pa upphettade apparatdelar hallas i suspension. Anvandningen av en rost, som i forsta hand ger anledning till overhettning, kan salunda und-varas. Genom alt reaktionskarlet ãr smalt, kan det alien snabbt tommas, sa att aven korta rostningsperioder kunna uppratthallas mycket noggrant. Dessutorn mojliggor denna snabba tOmningsprocess, att det rostade materialet mycket snabbt kan overforas till en kylanordning, vilken enligt uppfinningeu avenledes arbetar enligt fluidized-bed-principen. Denna utformning mojliggOr en sadan snabb nedkylning, att porerna i materialet mycket snabbare slutas an hos samtliga hittills kanda processer, vilket är sarskilt fordelaktigt for behandling av kaffe och kakao. Arombestandsdelarnas avgang undvikes darigenom i en utstrAckning, som icke varit mOjlig hos de hittills kanda forfaringssatten. Till foljd av den utomordentligt korta rostningsperioden intrader ej heller na- gon krackning och utbytet% storre an hos de Unda fOrfaringssatten, varvid samtidigt en battre kvalitet erhalles. The present invention relates to a device and a method for roasting and cooling coffee, cocoa, peanuts, malt 2, -, etc. in which the above-mentioned disadvantages are avoided and in addition great technical and economic advantages are achieved. The invention is based on a significant modification of the fluidized bed method. The fluidized phase is maintained in a reactor, the cross section of which rises and in which the differences in the specific gravity of the material which occurred during the roasting process can be automatically compensated. Because the opening angle of the reactor is formed as in a venturi nozzle, the material with an extremely small contact surface on heated apparatus parts can be kept in suspension. The use of a rust, which primarily gives rise to overheating, can thus be dispensed with. Because the reaction vessel is narrow, the alien can be emptied quickly, so that even short roasting periods can be maintained very carefully. In addition, this rapid emptying process enables the roasted material to be transferred very quickly to a cooling device which, according to the invention, also operates according to the fluidized-bed principle. This design enables such rapid cooling that the pores in the material close much faster in all hitherto known processes, which is particularly advantageous for the treatment of coffee and cocoa. The departure of the aroma constituents is thereby avoided to an extent which has not been possible with the hitherto known procedures. As a result of the extraordinarily short roasting period, no cracking and the yield% is greater than in the Unda fOrfaringssatten, whereby at the same time a better quality is obtained.

Genom forfaringssattet enligt uppfinning; en erhaller man salunda ett fullstandigt likformigt rostat, varken delvis alltfor starkt eller delvis alltfor svagt brant material med en maximal halt av aromsubstanser och utan Mist smakande krackningsprodukter med ett hittills icke uppnalt stort utbyte och med sit tat slutna porer, att materialet icke forlorar aromen aven efter hang lagringstid. By the method of the invention; one thus obtains a completely uniformly roasted, neither partly too strong nor partly too weakly steep material with a maximum content of aroma substances and without mist-tasting cracking products with a hitherto unattainable large yield and with its tat closed pores, that the material does not lose its aroma even after hung storage time.

Anordningen och forfaringssattet enligt uppfinningen kommer narmare att beskrivas med hfinvisning till en it bifogad ritning visad utforing,sform. The device and the method set according to the invention will be described in more detail with reference to an embodiment, form shown in the accompanying drawing.

Anordningens rostningsdel bestar av dif fusorformiga utvidgningar 1, 2, 3 och 4 hos ett venturiror. Harvid ar av sarskild betydelse, att oppningsvinkeln a hos delen 1 har den ratta storleken. Valjes denna vinkel alltfOr liten, blir kaffebtinornas rorelse alltfOr haftig och en malningseffekt upptrader. Blir vinkeln daremot alltfor stor, fordelas gasstromningen icke langre likformigt Over hela tvarsektionen och darvid uppstar risk, att skikt av icke tillrackligt flyttade och vidbranda materialmangder avlagras pa diffusorns vagg. Sokanden har konstaterat, att dessa fel alltid upptrada om vinkeln dr mindre an 3.0 resp. storre An 12° men ofta redan nar den är mindre an 5° eller st8rre an 70. En oppningsvinkel uppgaende till 60 ar salunda i allmanhet optimal. pa delen 1 aro anbragta delar 2, 3 och 4 med oppningsvinklarna ft, 7 och c5, av vilka vat oak en Sr storre an den framforghende. Stortaken av dessa Oppningsvinklar a, 13 och kan till en viss grad valjas fritt, men den storsta oppningsvinkeln 6 bar lampligen icke overstiga 15°, enar eljest aterigen risk for avlagring och vidbranning uppsta.r. Oppningsvinklarna avstammas till hoj den av de olika sektionerna pit sadant satt, att diffusorns totala volym blir sit stor, att apparaten har en viss volym for varje kilogram i apparaten infort kaffematerial. En apparatvolym uppgaende till c :a 5-15, foretradesvis 10, liter per kilogram kaffematerial har visat sig som sarskilt gynnsam. The roasting part of the device consists of diffuser-shaped extensions 1, 2, 3 and 4 of a venturi. In this case it is of particular importance that the opening angle α of the part 1 has the correct size. If this angle is chosen too small, the movement of the coffee beans becomes too violent and a grinding effect occurs. If, on the other hand, the angle becomes too great, the gas flow is no longer distributed uniformly over the entire cross section, and there is a risk that layers of insufficiently moved and burnt amounts of material are deposited on the diffuser wall. The applicant has found that these errors always occur if the angle is less than 3.0 resp. greater than 12 ° but often already when it is less than 5 ° or greater than 70. An opening angle of up to 60 is generally optimal. on the part 1 are placed parts 2, 3 and 4 with the opening angles ft, 7 and c5, of which water is also a Sr larger than the preceding one. The large roofs of these opening angles a, 13 and can to a certain extent be chosen freely, but the largest opening angle bar should not exceed 15 °, otherwise there is again a risk of deposition and burning. The opening angles are adjusted to the height of the various sections so that the total volume of the diffuser becomes large, that the apparatus has a certain volume for each kilogram of coffee material imported into the apparatus. An appliance volume of about 5-15, preferably 10, liters per kilogram of coffee material has proved to be particularly favorable.

Nedanfor delen 1 at anbragt gasinloppsmunstycket 5. Kaffebonorna inforas pneumatiskt fran ett magasin eller en silo 6 medelst en flakt 7 via ett med dubbla koniska hits for-sett cyklonkarl 8. Den medelst flakten 9 insugna rostningsluften erhaller i varmeutvaxlaren 10 medelst en brdnnare 11 den erforderliga temperaturen och intrader via en ventit 12 vid 13 i en luftbehallare 14. Denna kan vid den undre anden avstangas medelst en. konisk ventil 15. Rostningsluften lamnar apparaten vid 16 via en bromszon 17 och lampligen en studskropp 18, vilken forhindrar att kaffebonor kunna ryckas med. I cy,klonen 19 avlagsnas de fran de grona kaffebonorna bortforda hinnorna. Den vid 20 uttradande avgasen kan pa kant salt anvandas sitväl for ntvinning av koffein som for atervinning av det i gasen befintliga varmet. Rostningsprocessen kan kontrolleras genom provtagning vid 24. Below the gas inlet nozzle 5 arranged. The coffee beans are introduced pneumatically from a magazine or a silo 6 by means of a flake 7 via a cyclone vessel provided with double conical hits 8. temperature and enters via an vent 12 at 13 in an air container 14. This can be stopped at the lower spirit by means of a. conical valve 15. The roasting air leaves the appliance at 16 via a brake zone 17 and suitably a bounce body 18, which prevents coffee beans from being pulled along. In cy, clone 19, the membranes removed from the green coffee beans are removed. When the exhaust gas exits, salt can be used both for the recovery of caffeine and for the recovery of the heat present in the gas. The roasting process can be controlled by sampling at 24.

Nedanfor den egentliga rostningsdelen Sr nedkylningsdelen anbragt. Denna bestar av en lampligen uppat nagot utvidgad fluidizedbed-del 22, vilken vid den undre Laden Sr avstangd medelst en rost eller en perforerad platta 23. Ovanfor denna del ar aterigen anbragt en utvidgad bromsdel 21. En flat 26 bringar kall luft att via oppningen 25 och den perforerade plattan 23 passera genom nedkylningszonen 22 for att darefter via roret 27 och cyklonen 18 aterfora den till det fria. Till cyklonen 28 ar dessutom ansluten en ledning 29 med en ventil 30, som medelst ett sugror 31 na.r in i kyldelens fluidized-bed-parti. Genom att ventilen 30 oppnas, kan chargen efter slutfOrd kylning bortsugas via cyklonen 28 och Overforas till en silo 32. Fran denna tOmmes materialet medelst ett cellhjul 33 till en icke visad transportanordning eller omedelbart till forpackningsstationen. Below the actual roasting part Sr the cooling part is arranged. This consists of a suitably raised slightly expanded fluidized bed part 22, which at the lower Laden Sr is suspended by means of a grate or a perforated plate 23. Above this part is again arranged an extended brake part 21. A flat 26 brings cold air to via the opening 25 and the perforated plate 23 passes through the cooling zone 22 to then return it to the open air via the tube 27 and the cyclone 18. In addition, a line 29 is connected to the cyclone 28 with a valve 30, which by means of a suction pipe 31 enters the fluidized-bed portion of the cooling part. By opening the valve 30, the charge after final cooling can be sucked off via the cyclone 28 and transferred to a silo 32. From this the material is emptied by means of a cell wheel 33 to a transport device (not shown) or immediately to the packaging station.

Den beskrivna anordningen mojligg8r sitsom anforts, att ytterst korta rostnings- och nedkylningsperioder kunna noggrant uppratthallas. Den erforderliga rostningstiden beror i forsta hand pa rosttemperaturen och dess- — —3 utom pa den onskade rostningsgraden. Uppratthalles t. ex. en genomsnittlig rostningstemperatur av 20 G, erhaller man med de vanliga kaffeblandningarna via en rostningsperiod av 100 sek. ett rostat material, som motsvarar genomsnittssmaken. Vid langre rostningsperioder ph c:a 105-410 sek. erhaller man morkare, oljeaktiga sorter, vilka t. ex. foredragas i Frankrike och Ralien. Vid avkortning av rostningsperioden till c:a 95 sek. erhaller man ljusare sorter, vilka t. ex. foredragas i Amerika. Naturligtvis är det aven m5jligt att genomfora rostningsprocesser vid andra temperaturer an 220°, varvid man. vid hogre temperaturer maste avkorta rostningsperioden. Alt underskrida en rostningstemperatur av c:a 170° C är i allmanhet icke lampligt, och en okning av temperaturen Over 280° C medfor, att rostningsperioden maste fOrkortas i sa hog grad, att den endast med svarighet kan noggrant uppratthallas. Med rostningstemperatur menas icke den intradande varmluftens temperatur, utan den genomsnittliga temperaturen i fluidized-bedpartiet, ungefarligen i sektionen 2. Denna temperatur varierar under rostningsprocessen och sjunker frau ett hagre varde till ett minimum samt stiger i flagon grad igen vid processens slut. De angivna siffrorna avse temperaturens medelvarde. The described device makes it possible, as mentioned, that extremely short periods of roasting and cooling can be accurately maintained. The required roasting time depends primarily on the roasting temperature and its - - —3 except for the desired degree of roasting. Maintained e.g. an average roasting temperature of 20 G, is obtained with the usual coffee blends via a roasting period of 100 sec. a roasted material, which corresponds to the average taste. For longer roasting periods ph approx. 105-410 sec. you get darker, oily varieties, which e.g. preferred in France and Ralien. When shortening the roasting period to about 95 sec. lighter varieties are obtained, which e.g. lectured in America. Of course, it is also possible to carry out roasting processes at temperatures other than 220 °, whereby one. at higher temperatures the roasting period must be shortened. Any fall below a roasting temperature of about 170 ° C is generally not appropriate, and an increase in the temperature above 280 ° C means that the roasting period must be shortened to such an extent that it can only be maintained accurately with responsibility. By roasting temperature is meant not the temperature of the incoming hot air, but the average temperature in the fluidized bed portion, approximately in section 2. This temperature varies during the roasting process and drops from a low value to a minimum and rises sharply again at the end of the process. The figures given refer to the mean value of the temperature.

Rostningsluftmangden valj es enligt tvh synpunkter. Hastigheten i venturirorets hals 34, maste uppga till atminstone 25-30 m/sek. vid 0° C °eh 760 mm Hg. Underskrides denna hastighet kan en fritt sva.vande suspension icke langre med sakerhet uppratthallas, sh att fOrdelen med rostningen utan rost icke langre kan utnyttjas. Overskrides denna hastighet avsevart, erhaller man en malningseffekt. The amount of roasting air is chosen according to two points of view. The speed in the neck 34 of the venturi must be at least 25-30 m / sec. at 0 ° C ° eh 760 mm Hg. If this speed is exceeded, a free-floating suspension can no longer be maintained with certainty, so that the advantage of roasting without rust can no longer be utilized. If this speed is exceeded considerably, a grinding effect is obtained.

Dessutom maste rostluftmangden valjas pa sadant satt, att det anvandbara varmet är tillrackligt for genomforandet av rostningsprocessen. Sokanden har konstaterat, att 180 --200 kcal behovas per kg orostat kaffe. In addition, the amount of rust air must be selected in such a way that the usable heat is sufficient for carrying out the roasting process. The applicant has established that 180 --200 kcal are needed per kg of unroasted coffee.

Sedan rostningsprocessen har slutfOrts frankopplas rostningsluften under en kort period genom att ventilen 12 avstanges och laset 15 Oppnas. Under tyngdkraftens och sugflaktens 26 inverkar sjunker det rostade kaffet Mom mycket kort tid ned till nedkylningsdelen och virvlas uppat i denna medelst kylluften. Vid en luftintradestemperatur av 20° C kunna de rostade kaffebonorna Mom 90 sek. kylas ned till 25° C, cm 300 m kylluft anvandas per kg orostat kaffe. Darigenom mojliggores att rostningsprocessen och nedkylningen kunna styras pa sadant satt, att hada processerna kunna utforas mom lika langa tidsperioder och att alltid en charge nedkyles under det att den efterfoljande redan rostas. After the roasting process has been completed, the roasting air is disconnected for a short period by shutting off the valve 12 and opening the lasing 15. Under the influence of gravity and the suction surface 26, the roasted coffee Mom sinks for a very short time down to the cooling part and is swirled upwards in it by means of the cooling air. At an air inlet temperature of 20 ° C, the roasted coffee beans Mom 90 sec. cooled down to 25 ° C, cm 300 m cooling air is used per kg of unroasted coffee. This makes it possible for the roasting process and the cooling to be controlled in such a way that the processes can be carried out for equal periods of time and that a batch is always cooled while the subsequent roasting is already being roasted.

Styrorganens 12, 15 och 30 samt de koniska lasens rorelse i karlet 8 kan pa kant salt styras automatiskt. Detta desto mera som rostnings- och kylningsprocessen inom exakt kon- stan.ta tider kunna slutforas, om mangdeu och temperaturen av rostnings- och kylluften hallas konstant. The movement of the guide means 12, 15 and 30 as well as the conical lasers in the vessel 8 can be controlled automatically on the edge of the salt. This is all the more so as the roasting and cooling process can be completed within precisely constant times, if the mangdeu and the temperature of the roasting and cooling air are kept constant.

Den beskrivna utforingsformen av uppfinningen innehaller ett stort antal detaljer, vilka arc lampliga men icke under alla forhallanden nodvandiga. Salunda kan rostningsdelen t. ex. besta av mer eller mindre an fyra koniska delar med olika oppningsvinklar eller aven av en enda del med kontinuerligt uppat atvidgad oppningsvinkel. Dessutom kunna den koniska ventilen. 15 liksom samtliga andra avstangningsorgan ersattas genom nagot annat lampligt avstangningsorgan och rostningsluften kan i stallet fOr genom varmeutvaxling med varma fOrbranningsgaser aven upphettas pa annat shit, 1. ex. elektriskt. Gyklonen 19, är, sarskilt om rostningsluften icke skald utnyttj as, icke erforderlig. Avlagsnandet av materialet ur silon 32 kan i stallet f6r medelst ett cellhjul oven fOretagas pa annat satt. Dessutom kan nedkylnings- och rostningsluften Even renas och fuktas eller torkas fore anvandningen. The described embodiment of the invention contains a large number of details which are suitable but not necessary in all circumstances. Salunda can the roasting part e.g. consists of more or less than four conical parts with different opening angles or also of a single part with a continuously extended widening opening angle. In addition, be able to the conical valve. As well as all other shut-off means are replaced by some other suitable shut-off means and the roasting air can also be heated on another shit instead of by heat exchange with hot combustion gases, 1. ex. electrically. Gyklonen 19, especially if the roasting air is not to be used, is not required. The removal of the material from the silo 32 can be carried out in another way instead of by means of a cell wheel above. In addition, the cooling and roasting air can even be cleaned and moistened or dried before use.

Claims

Patent claim:

1. Provided for batch roasting of coffee by means of an ascending strain of hot gases in a roasting chamber (shaft), characterized in that the roasting is carried out in a diffuser-shaped expanded shaft while maintaining such a gas velocity, preferably 25-60 m / sec. ., that in the treatment gas a free-floating tat suspension of the coffee beans is formed, which remains in the roasting chamber during the entire roasting time and only after the roasting is completed is taken out at the lower part of the roasting chamber via the gas inlet nozzle and caused to fall into an underlying vortex layer principle.

2. a salt according to claim 1, characterized in that the final roasted coffee is cooled immediately after final roasting by means of cold gases in a swirling suspension.

3. Set according to patent claim 2, characterized in that the amount and temperature of the roasting air is constant and that the desired degree of roasting is obtained only by varying the roasting time.

Set according to claims 2 and 8, characterized in that roasting periods of 90-110 sec, and a roasting temperature of 220 ° C are used.

Device for carrying out the set according to claim 1, characterized in that the device comprises an upwardly extended and without rust grille made of scam (1, 2, 3, 4) with an opening angle (a) of at least 30 and at most 12 °, preferably to between 5-70, at the narrowest lower part (1) of the shaft above the inlet nozzle (5) Or - 186_642 - the hot gases, that the shaft is formed as a venturi nozzle with increasing opening angles (, 8, 7, 6) at each of the shaft parts (2, 3, 4) connected upwards to the narrowest shaft part and that below the bottom of the shaft a discharge device for the finalized coffee is arranged, which is in direct connection with a cooler operating according to the vortex layer principle. Request Publications: U.S. Patent Nos. 748,894, 7891109, 790,162, 1,459,326, 2,381,493, 2,497,501.