DK173016B1

DK173016B1 - Method and apparatus for removal of liquid from particulate material

Info

Publication number: DK173016B1
Application number: DK199801249A
Authority: DK
Inventors: Arne Sloth Jensen
Original assignee: Asj Holding Aps
Priority date: 1998-01-09
Filing date: 1998-10-02
Publication date: 1999-11-15
Also published as: DK199801249A

Description

1 DK 173016 B11 DK 173016 B1

Fremgangsmåde og apparat til fjernelse af væske fra partikelformet materialeMethod and apparatus for removing liquid from particulate material

Opfindelsen angår en fremgangsmåde til fjernelse af væske fra partikelformet materiale ved fordampning gennem tilførsel af varme i hovedsagen overført af 5 overhedede dampe af de væsker, der findes i det partikelformede materiale, hvilken fremgangsmåde finder sted i et i hovedsagen lukket system.The invention relates to a method for removing liquid from particulate material by evaporation through the application of heat generally transmitted by superheated vapors of the liquids contained in the particulate material which takes place in a substantially closed system.

Opfindelsen angår tillige et apparat til udøvelse af en sådan fremgangsmåde, hvilket apparat består af en i hovedsagen lukket beholder, der har midler til til- 10 førsel af partikelformet materiale, hvorfra der skal fjernes væske, midler til fjernelse af tønet partikelformet materiale, midler til cirkulering af overhedede dampe i beholderen, midler til tilførsel af varmeenergi til disse dampe samt midler til separering af støvpartikler fina dampene.The invention also relates to an apparatus for practicing such a method, which apparatus consists of a substantially closed container having means for supplying particulate material from which liquid is to be removed, means for removing thinned particulate material, means for circulation of superheated vapors in the container, means for supplying heat energy to these vapors and means for separating dust particles from the fine vapors.

15 Det partikelformede materiale kan indeholde partikler, der er af såvel ensartet størrelse som partikler, der afviger væsentlig fra hinanden i størrelse. Materialet kan indeholde flere forskellige flygtige og væskeformede stoffer, der ønskes fjernet, hvilket sker i en atmosfære af overhedet damp af de samme flygtige væsker. Hvis væsken, der ønskes fjernet, er vand, er der tale om en tørringsproces.The particulate material may contain particles of uniform size as well as particles which differ substantially in size. The material may contain several different volatile and liquid substances which are desired to be removed, which occurs in an atmosphere of superheated steam of the same volatile liquids. If the liquid to be removed is water, it is a drying process.

20 hvor tørringen foregår i en overhedet vanddamp. Det vil dog forstås, at hvor der I det følgende skrives om tørringsprocesser, vil der lige såvel kunne indgå lignende processer, hvor der fjernes andre væsker end vand fra det partikelformede materiale.20 where the drying takes place in a superheated water vapor. However, it will be understood that where the following describes drying processes, similar processes may also be included in which liquids other than water are removed from the particulate material.

25 En fremgangsmåde og et apparat af den indledningsvis nævnte art kendes eksempelvis fra EP patentansøgning nr. 82 850018.1 (publikationsnr. EPA method and apparatus of the kind mentioned above are known, for example, from EP Patent Application No. 82 850018.1 (Publication No. EP

0.058.651 A1). Ved denne kendte teknik foregår tørringen i serieforbundne lodrette rør eller rørvarmevekslere, hvorigennem de partikler, der skal tørres, strømmer, båret af overhedet vanddamp. Denne metode giver en ensartet op- 30 holdstid, som er relativ kort, da man i praksis ikke kan bygge tilstrækkeligt høje 2 DK 173016 B1 og tilstrækkeligt mange lodrette rør og varmevekslere. Eksempelvis kan man kun få et minuts opholdstid med anvendelse af 30 lodrette behandlingszoner, der hver er 40 m høje, når strømningshastigheden er 20 m/sek. Dette betyder, at partiklerne må have en meget ensartet partikelstørrelse og en meget kort tørre-5 tid, hvorfor denne kendte metode kun er egnet til små ensartede partikler.0.058.651 A1). In this prior art, the drying takes place in series-connected vertical pipes or tube heat exchangers, through which the particles to be dried flow, carried by superheated water vapor. This method gives a uniform residence time, which is relatively short, since in practice it is not possible to build sufficiently high and sufficient vertical pipes and heat exchangers. For example, only one minute of residence time can be obtained using 30 vertical treatment zones, each 40 m high when the flow rate is 20 m / sec. This means that the particles must have a very uniform particle size and a very short drying time, which is why this known method is only suitable for small, uniform particles.

Endvidere kendes en fremgangsmåde og et apparat fra EP 0.153.704, der omfatter en række lodrette langstrakte behandlingszoner, op Igennem hvilke der føres overtiedet damp. Over behandlingszoneme er der en fælleszone, hvortil 10 partikler med reduceret væskeindhold overføres, idet partiklerne herfra føres videre til udtagszonen eller udtagszoneme. I det mindste en del af partiklerne kan ved behandlingszonemes nedre ender føres fra én behandlingszone til den næste gennem forbindelseskanaler.Furthermore, a method and apparatus of EP 0.153,704 comprising a number of vertical elongated treatment zones are known, through which excess steam is conducted. Above the treatment zones, there is a common zone to which 10 particles of reduced fluid content are transferred, the particles being transferred from there to the withdrawal zone or withdrawal zones. At least a portion of the particles at the lower ends of the treatment zones can be passed from one treatment zone to the next through connecting channels.

15 Den langstrakte lodrette behandlingszoneform betyder ved denne kendte teknik, at en væsentlig del af partiklerne i mellemstørrelse får en for lang opholdstid. De bliver derfor tørnet til et uønsket højt tørstofindhold, som forringer produktkvaliteten, da genoptagelsen af vand for mange produkters vedkommende derved forringes. Endvidere medfører den høje byggeform forholdsvis høje omkostnin-20 ger til byggeri og installation. Endelig er der ved inddelingen i behandlingszoner en forholdsvis stor risiko for, at vådt partikelformet materiale vil blokere i appa-ratets første zoner dels ved påklæbninger og dels ved, at damp kondenserer på produktet og gør det så meget tungere, at det ikke mere kan holdes i bevægelse af dampstrømmen.The elongated vertical treatment zone shape, in this prior art, means that a substantial portion of the medium sized particles will have too long a residence time. They are therefore dried to an undesirably high solids content which degrades product quality as the re-uptake of water for many products thereby deteriorates. Furthermore, the high construction costs entail relatively high costs for construction and installation. Finally, when divided into treatment zones, there is a relatively high risk that wet particulate material will block in the first zones of the device partly by adhesives and partly by steam condensing on the product and making it so much heavier that it can no longer be held. in motion of the vapor stream.

2525

Med opfindelsen tilstræbes der opnået en fremgangsmåde og et apparat, der undgår de nævnte ulemper i forbindelse med anvendelse af flere behandlingszoner, og idet der opnås en optimal behandlingstid for alle størrelser af partikler i det partikelformede materiale.It is an object of the invention to provide a method and apparatus which avoids the aforementioned disadvantages associated with the use of multiple treatment zones, and to achieve an optimal treatment time for all sizes of particles in the particulate material.

30 3 DK 173016 B130 3 DK 173016 B1

Dette opnås med en fremgangsmåde af den indledningsvis nævnte art, der er udformet således, som det fremgår af den kendetegnende del af krav 1, samt et apparat af den indledningsvis nævnte art, der er udformet således, som det fremgår af den kendetegnende del af krav 4.This is achieved by a method of the type mentioned in the preamble, as stated in the characterizing part of claim 1, and an apparatus of the kind mentioned in the preamble, which is designed as shown in the characterizing part of claim 1. 4th

55

Idet der alene anvendes et vandretliggende kammer, opnås en passende lav udformning af beholderen til udøvelse af fremgangsmåden, ligesom apparatet får en passende lav byggehøjde. Ved den anviste dampstrømning henholdsvis den anviste udformning af bunden i det ringformede kammer opnås, at der sik-10 res en cirkulerende eller roterende bevægelse i det i det væsentlige lodrette plan af det partikelformede materiale, således at alle produktets dele holdes i bevægelse, og således, at der opnås en tæt kontakt mellem produktet og de overhedede dampe.Using only a horizontal chamber, a suitably low design of the container for carrying out the process is obtained, and the apparatus is given a suitably low building height. By the vapor flow or the design of the bottom of the annular chamber, respectively, it is achieved that a circulating or rotating movement is ensured in the substantially vertical plane of the particulate material so that all parts of the product are kept in motion, and thus , that close contact is achieved between the product and the superheated vapors.

15 Hensigtsmæssige udførelsesformer for fremgangsmåden Ifølge opfindelsen er angivet i de uselvstændige krav 2 og 3. og hensigtsmæssige udførelsesformer for apparatet ifølge opfindelsen fremgår af de uselvstændige krav 5 -10.Suitable embodiments of the method According to the invention are set out in the dependent claims 2 and 3. and suitable embodiments of the apparatus according to the invention are set forth in the dependent claims 5-10.

Opfindelsen skal i det følgende forklares nærmere under henvisning til tegnln-20 gen, hvor fig. 1 viser et lodret snit af bunddelen til et apparat ifølge opfindelsen til fjernelse af væske fra partikelformet materiale, taget langs linien l-l på fig. 2, 25 fig. 2 viser et vandret snit af bunddelen vist på fig. 1, taget langs linien II - II på fig. 1.The invention will now be explained in more detail with reference to the drawing, in which fig. 1 is a vertical sectional view of the bottom portion of an apparatus according to the invention for removing liquid from particulate material taken along line 1--1 of FIG. 2, FIG. 2 shows a horizontal section of the bottom part shown in FIG. 1 taken along line II - II of FIG. First

fig. 3 viser et lodret snit af et konisk overgangsstykke til et apparat ifølge opfindelsen, fig. 4 viser et vandret snit af overgangsstykket vist på fig. 3, taget langs 30 linien IV - IV på fig. 3, 4 DK 173016 B1 fig. 5 viser et lodret snit af den øverste del af et apparat ifølge opfindelsen. taget langs linien V-V på fig. 6, fig. 6 viser et vandret snit af deien vist på fig. 5. taget langs linien Vl-Vi på fig. 5, og 5 fig. 7 viser et lodret snit af en udløbsåbning med tilhørende ejektor. taget langs linien VII-VII på fig. 6.FIG. 3 is a vertical sectional view of a tapered transition piece for an apparatus according to the invention; FIG. 4 shows a horizontal section of the transition piece shown in FIG. 3, taken along line IV - IV of FIG. 3, 4 DK 173016 B1 fig. 5 shows a vertical section of the upper part of an apparatus according to the invention. taken along line V-V of FIG. 6, FIG. 6 shows a horizontal section of the dough shown in FIG. 5. taken along the line V1-Vi in FIG. 5 and 5 in FIG. 7 shows a vertical section of an outlet opening with associated ejector. taken along line VII-VII of FIG. 6th

Apparatet ifølge opfindelsen består i hovedsagen af tre dele, der er placeret ovenpå hinanden, nemlig en bunddel 9 som vist i fig. 1 og 2, et konisk over-10 gangsstykke som vist i fig. 3 og 4 samt en øverste del 20, der er vist på fig. 5 og 6.The apparatus according to the invention consists essentially of three parts placed one on top of the other, namely a bottom part 9 as shown in FIG. 1 and 2, a tapered transition piece as shown in FIG. 3 and 4 as well as a top part 20 shown in FIG. 5 and 6.

Bunddelen 9 består som det ses på fig. 1 og 2 af en i det væsentlige cylindrisk beholder, der som ydervæg har en ydre cylinderflade 3. Inden i bunddelen be-15 finder der sig et lavt ringformet eller delvis ringformet kammer 1, der er åben foroven og som til siderne begrænses af dels den ydre cylinderflade 3 og dels en indre cyiinderflade 2. Nedadtil begrænses det ringformede kammer 1 af en dobbeltkrum bund 10. Denne dobbeltkrumme bund kan have et tværsnit af form som en oval eller således som vist på fig. 1 en halvcirkel, men kan også have et 20 tværsnit, der afviger fra en oval- eller cirkelform. Bunden 10 har det dybeste sted på den midterste halvdel, og siderne buer opad mod kammerets indre og ydre kant, dvs. mod den indre cylinderflade 2 og den ydre cyiinderflade 3. Af fremstillingsmæssige årsager kan bunden bestå af enkeltkrumme eller plane pladestykker, der samles således, at de tilnærmer sig den runde form. Den dob-25 beltkrumme bund 10 er endvidere perforeret, idet der er udformet en række åbninger 11 i bunden, hvilke åbninger senere skal beskrives nærmere.The bottom part 9 consists as seen in FIG. 1 and 2 of a substantially cylindrical container having an outer cylindrical surface 3. As an outer wall, a low annular or partially annular chamber 1, which is open at the top and which is limited to the sides by outer cylinder surface 3 and partly an inner cylinder surface 2. Downwardly, the annular chamber 1 is constrained by a double-curved bottom 10. This double-curved bottom may have a cross-sectional shape as an oval or as shown in FIG. 1 is a semicircle, but may also have a cross section which differs from an oval or circular shape. The bottom 10 has the deepest place on the middle half, and the sides arc upward toward the inner and outer edges of the chamber, ie. against the inner cylinder surface 2 and the outer cylindrical surface 3. For manufacturing reasons, the bottom may consist of single curved or flat plate pieces which are joined together to approximate the round shape. The double curved bottom 10 is further perforated, a series of openings 11 in the bottom being formed, which openings will be described in more detail later.

Bunddelen 9 af apparatet har endvidere et tilførselsrør 5 for partikelformet materiale, der skal tørres, samt et afgangsrør 6 for materiale, der er tørret. Den indre 30 cyiinderflade 2 danner et rørformet midterrum 4, der (som vist med punkterede 5 DK 173016 B1 linier) forløber op gennem de øvrige dele af apparatet og nedadtil udmunder i et rum under det ringformede kammer 1.The bottom part 9 of the apparatus further has a particulate material supply pipe 5 to be dried, and a discharge pipe 6 for dried material. The inner 30 cylindrical surface 2 forms a tubular center space 4 which (as shown by dashed lines) extends through the other parts of the apparatus and opens downwards into a space below the annular chamber 1.

Endelig er der I det ringformede kammer placeret indhængte plader 13. således 5 som illustreret på fig. 1 og 2. Disse plader, hvis funktion senere skal beskrives, kan udgå fra såvel den indre cylinderflade 2 (således som vist) som fra den ydre cylinderflade 3 (ikke vist på fig. 1 og 2), Idet der alene kan anvendes én af disse former for placering eller en kombination af disse. De Indhængte plader 13 kan være bukkede fremad eller knækkede langs en linie 14 som vist.Finally, in the annular chamber, there are placed plates 13, thus 5, as illustrated in FIG. 1 and 2. These plates, the function of which will be described later, can be based on both the inner cylinder surface 2 (as shown) and from the outer cylinder surface 3 (not shown in Figures 1 and 2), since only one of the these types of placement or a combination of these. The pendant plates 13 may be bent forward or broken along a line 14 as shown.

1010

Funktionen af bunddelen 9 af apparatet skal nu beskrives nærmere. Det partikelformede materiale, der skal tørres, tilføres kontinuert til det ringformede kammer 1 gennem tilførselsrøret 5 ved hjælp af ikke viste, men almindeligt kendte fremføringsmidler. Samtidig tilføres der overhedet damp som vist med pilen 8 fra 15 oven ned gennem det rørformede midterrum 4 til rummet under det ringformede kammer 1, hvorfra den overhedede damp gennem åbningerne 11 i den dobbeltkrumme bund 10 strømmer op I det ringformede kammer 1.The function of the bottom part 9 of the apparatus will now be described in more detail. The particulate material to be dried is fed continuously to the annular chamber 1 through the feed tube 5 by means of feedstuffs which are not shown but commonly known. At the same time, as shown with arrow 8 from above, superheated steam is fed down through the tubular center compartment 4 to the space below the annular chamber 1, from which the superheated steam flows through the openings 11 in the double-curved bottom 10 into the annular chamber 1.

Åbningerne 11 i bunden 10 består i en kombination af åbninger dels som simple 20 huller, hvorigennem dampen strømmer vinkelret på bundpladen, og dels åbninger, som giver dampen en indstrømningsretning, som danner en vinkel mellem 0° og 90° med pladen. Denne vinkel vil fortrinsvis ligge mellem 0° og 80°, og i praksis vil vinklen som regel være begrænset til et interval mellem 0° og 30°.The openings 11 in the bottom 10 consist of a combination of openings partly as simple 20 holes through which the steam flows perpendicular to the base plate and partly openings which give the steam an inflow direction which forms an angle between 0 ° and 90 ° with the plate. This angle will preferably be between 0 ° and 80 °, and in practice the angle will usually be limited to a range between 0 ° and 30 °.

Endvidere er det procentvise hulareal i den del af pladen, der er nærmest den 25 ydre periferi, større end i den del, som er nærmest den indre periferi. Dette vil sammen med indstrømningsretningen af dampen give en roterende bevægelse af det partikelformede produkt i det væsentlige i det lodrette plan, således som vist med pilene 12 på fig. 1. Dermed sikres bevægelse af alle partikelstørrelser i materialestrømmen. Endvidere kan den rundtgående bevægelse af partiklerne 6 DK 173016 B1 også understøtte eksempelvis en coatningsproces eller en tilførsel af væske, der ønskes inddampet sammen med partiklerne.Furthermore, the percentage of hollow area in the portion closest to the outer periphery is larger than that of the portion closest to the inner periphery. This, together with the direction of inflow of the vapor, will cause a rotary movement of the particulate product substantially in the vertical plane, as shown by the arrows 12 in FIG. 1. Thus, movement of all particle sizes in the material flow is ensured. Furthermore, the circumferential movement of the particles may also support, for example, a coating process or a supply of liquid which is desired to be evaporated together with the particles.

Vinkelstørrelsen af de vinklede åbninger 11 i bunden 10 kan udføres således, at 5 vinkelstørrelsen er afhængig af, hvor den pågældende åbning 11 er placeret dels i radiær retning, således at der sikres en passende roterende bevægelse, og dels i perifer retning, således at der kan sikres en bevægelse af partikelstrømmen rundt i det ringformede kammer 1 fra tilførselsrøret 5 til afgangsrøret 6. Retningen af indblæsningen af overhedet damp kan således anvendes til at 10 fremme eller reducere transporten fremad i det ringformede kammer.The angular size of the angled apertures 11 in the bottom 10 can be made such that the angular size is dependent on where the aperture 11 is located partly in the radial direction to provide an appropriate rotary motion and partly in the circumferential direction so that Thus, a movement of the particle flow around the annular chamber 1 can be ensured from the supply pipe 5 to the outlet pipe 6. The direction of the supply of superheated steam can thus be used to promote or reduce the transport forward in the annular chamber.

Herudover kan de indhængte plader 13 anvendes til at styre transporten. Disse plader vil almindeligvis ikke være radiære, men vil være tilpasset i en sådan retning, at transporten fremad i det ringformede kammer 1 sker tilpas hurtigt. End-15 videre kan disse plader som tidligere nævnt være bukkede fremad eller knækkede langs en linie 14 som vist med det fonnål at sikre den fornødne transporthastighed af det partikelformede produkt. Endelig kan pladerne 13 som nævnt udgå fra den indre cylinderflade 2 og/eller den ydre cylinderflade 3, idet der ved en kombination af disse ophængningsmåder opnås en art labyrinteffekt mellem pla-20 deme.In addition, the hung plates 13 can be used to control the transport. These plates will generally not be radial, but will be adapted in such a way that the transport forward in the annular chamber 1 is adjusted rapidly. Further, as previously mentioned, these plates may be bent forward or broken along a line 14 as shown with the need to ensure the required transport speed of the particulate product. Finally, as mentioned, the plates 13 can be formed from the inner cylinder surface 2 and / or the outer cylinder surface 3, whereby a combination of these suspension modes obtains a kind of maze effect between the plates.

Den fornødne energi til fordampning af væske fra partiklerne i materialestrømmen kommer dels fra den tilførte overhedede damp, men en del kan hidrøre fra de indhængte plader 13 samt ydervæggene af apparatet, som kan være varme-25 flader. Disse plader 13 kan eksempelvis udformes af sammensvejste plader, der imellem sig danner et hulrum, hvortil der ledes damp af et højere tryk end det, der hersker i det ringformede kammer.The energy required to evaporate liquid from the particles in the material stream comes partly from the superheated steam supplied, but a portion may be from the suspended plates 13 as well as the outer walls of the apparatus, which may be hot surfaces. For example, these plates 13 may be formed of welded plates forming between them a cavity to which steam is supplied by a higher pressure than that prevailing in the annular chamber.

Når det partikelformede produkt transporteres rundt i det ringformede kammer 1.When the particulate product is transported around the annular chamber 1.

30 vil det til slut nå hen til en separatorvæg 7, der i umiddelbar nærhed af afgangs- 7 DK 173016 B1 røret 6 vil standse produktstrømmens bevægelse fremad i ringkammeret og føre produktet ud af afgangsrøret 6, gennem hvilken produktet kan føres videre ved hjælp af ikke viste almindeligt kendte fremføringsmidler.30, it will eventually reach a separator wall 7 which, in the immediate vicinity of the outlet pipe 6, will stop the movement of the product flow forward in the annulus and lead the product out of the outlet pipe 6 through which the product can be passed by showed commonly known conveying means.

5 Som vist på fig. 2 er tilførselsåbningen 5 ikke placeret i den allerforeste del af det ringformede kammer 1, men således, at der er en vis afstand mellem separator-væggen 7 og tilførselsåbningen 5. Herved opnås, at det tilførte partikelformede fugtige produkt, der tilføres, straks blandes med delvist tørret materiale fra den forreste del af det ringformede kammer, således at risikoen for belægninger og 10 tilklæbninger med det fugtige nyindførte materiale reduceres væsentligt.5 As shown in FIG. 2, the feed opening 5 is not located in the very front of the annular chamber 1, but so that there is some distance between the separator wall 7 and the feed opening 5. This results in the immediate mixing of the supplied particulate moist product with partially dried material from the front of the annular chamber so that the risk of coatings and adhesions with the moist newly introduced material is substantially reduced.

Som almindeligt anvendt i forbindelse med tørrekamre af fluid-bed typen er der oven over selve fiuid-bed’en, dvs. i dette tilfælde det ringformede kammer 1, et yderligere kammer med et større vandret tværsnitsareal. Overgangen hertil er et 15 konisk overgangsstykke 15, der er udformet således som vist på fig. 3 og 4, hvor der ligeledes er vist ved punkterede linier, hvorledes det koniske overgangsstykke er forbundet med de øvrige to dele af apparatet Som det ses, går den ydre cylinderflade 3 fra bunddelen 9 af apparatet over i en konisk ydervæg 16 for det koniske overgangsstykke 15, og den indre cylinderflade 2 fra bunddelen fort-20 sætter op gennem det koniske overgangsstykke 15, således at det rørformede midterrum 4 også genfindes her. Den overhedede damp, der er strømmet op gennem det ringformede kammer 1, hvor det har tilført det partikelformede materiale dels varme og dels en roterende bevægelse, vil strømme videre op gennem det koniske overgangsstykke 15 mellem den Indre cylinderflade 2 og den koni-25 ske ydervæg 16, idet dampen vil medføre medrevne partikler. Den opadstrøm-mende damp har en så stor hastighed, at en væsentlig del af partkleme vil blive ført op i dette stykke, hvor disse partikler vil blive tørrede.As commonly used in connection with fluid bed type drying chambers, there is above the fluid bed itself, i.e. in this case the annular chamber 1, a further chamber with a larger horizontal cross-sectional area. The junction therein is a conical junction 15 formed as shown in FIG. 3 and 4, also shown by dashed lines, how the tapered transition piece is connected to the other two parts of the apparatus. As can be seen, the outer cylinder surface 3 from the bottom part 9 of the apparatus enters a tapered outer wall 16 for the tapered transition piece. 15, and the inner cylinder surface 2 from the bottom part 20 extends through the tapered transition piece 15 so that the tubular center space 4 is also found here. The superheated steam flowing up through the annular chamber 1, where it has supplied both the particulate material heat and partly a rotary movement, will flow further up through the tapered transition piece 15 between the inner cylinder surface 2 and the conical outer wall. 16, as the vapor will cause entrapped particles. The upward flowing vapor is of such a high velocity that a substantial portion of the particles will be fed into this section where these particles will be dried.

Den væsentligste del af de medrevne partikler vil blive udskilt i det koniske over-30 gangsstykke 15, idet de her bliver separeret ved en metode, der har træk fælles 8 DK 173016 B1 med lamelsedimentation. I det koniske overgangsstykke 15 er der mellem den indre cylinderflade 2 og den koniske ydervæg 16 anbragt et antal plader 17, der udstråler fra den indre cylinderflade 2 ud mod den koniske ydervæg 16. Disse plader 17, hvoraf kun nogle få er vist på fig. 4, udstråler ikke nødvendigvis radi-5 ært fra den indre cylinderflade 2. Der er anbragt et antal plader 17 i det koniske overgangsstykke 15 svarende til, at afstanden mellem pladerne fortrinsvis vil være mellem 200 mm og 500 mm. For at opnå en afstand, der er indenfor disse grænser, kan der være indsat stykker af sådanne plader, eksempelvis halve plader, længst fra apparatets centrum. Pladerne 17 er anbragt, så de hælder frem-10 ad i transportretningen og kan eventuelt have en eller flere bukkelinier 18 som vist.The major part of the entrained particles will be separated into the tapered transition piece 15, here being separated by a method having features common to lamella sedimentation. In the tapered transition piece 15, a plurality of plates 17 projecting from the inner cylinder surface 2 towards the tapered outer wall 16 are arranged between the inner cylinder surface 2 and the conical outer wall 16, only a few of which are shown in FIG. 4, does not necessarily radiate radially from the inner cylinder surface 2. A plurality of plates 17 are arranged in the conical transition piece 15 corresponding to the distance between the plates being preferably between 200 mm and 500 mm. In order to obtain a distance within these limits, pieces of such plates, for example half plates, may be inserted furthest from the center of the apparatus. The plates 17 are arranged so as to incline 10 in the direction of transport and may optionally have one or more bending lines 18 as shown.

Pladerne 17 når ikke ud til den koniske ydervæg 16, men der kan dog være steder, fortrinsvis foroven, hvor pladerne har forlængelser 19 og når ud til den koni-15 ske ydervæg 16 for at blive båret af denne. På pladerne 17 kan der endvidere sidde ribber (ikke vist) til at afstive de forholdsvis store plader. Disse ribber kan endvidere med en passende udformning være med til at styre strømmen af damp og partikelformet materiale.The plates 17 do not reach the tapered outer wall 16, but there may, however, be places, preferably at the top, where the plates have extensions 19 and reach the tapered outer wall 16 to be supported by it. Furthermore, on the plates 17, ribs (not shown) can be supported to support the relatively large plates. Furthermore, these ribs can, with a suitable design, help control the flow of steam and particulate material.

20 Damp og medrevne partikler vil passere op mellem pladerne 17, hvor der vil ske en afbøjning af strømmen på grund af pladernes hældning, og hvor damphastigheden vil aftage, således at partikler vil falde ned på den næste underliggende plade 17. Fra denne plades overside vil partiklerne glide nedad til spalten mellem pladen og den koniske ydervæg 16, og fra den koniske ydervæg ned i det 25 ringformede kammer 1, hvorfra partiklerne igen vil blive blæst op mellem pladerne 17 længere fremme i transportretningen. Ved at dampen passerer mellem pladerne 17 hindres de fleste partikler i at nå ovenud af det koniske overgangsstykke 15, og samtidig transporteres partikler fremad i apparatet. Kun støvpartikler vil af dampen blive ført ovenud af det koniske overgangsstykke 15. Plader-30 ne 17 kan på samme måde som de indhængte plader 13 være opvarmede og 9 DK 173016 B1 kan således tjene som varmeflader. ligesom ydervæggen 16 tjener som varme-flade.20 Vapor and entrained particles will pass up between the plates 17, where the flow will be deflected due to the inclination of the plates and where the steam velocity will decrease, so that particles will fall onto the next underlying plate 17. From the top side of this plate, the particles slide downward to the gap between the plate and the tapered outer wall 16, and from the tapered outer wall down into the annular chamber 1, from which the particles will again be inflated between the plates 17 further forward in the direction of transport. By passing the steam between the plates 17, most particles are prevented from reaching above the conical transition piece 15, and at the same time particles are transported forward in the apparatus. Only dust particles will be carried by the steam above the conical transition piece 15. The plates 17 can be heated in the same way as the suspended plates 13 and thus serve as heating surfaces. just as the outer wall 16 serves as a hot surface.

Også i det koniske overgangsstykker 15 er der placeret en separatorvæg 7, så-5 ledes som vist på fig. 4. Denne separatorvæg 7 forhindrer, at partikelformet materiale, der er ført frem til enden af det ringformede kammer 1 og således er tørret, vil kunne blæses op af dampen og over i den forreste del af det ringformede kammer påny.Also in the tapered transition pieces 15 is a separator wall 7, which is guided as shown in FIG. 4. This separator wall 7 prevents particulate material advancing to the end of annular chamber 1 and thus dried from being blown up by the steam and over into the front part of the annular chamber.

10 Det koniske overgangsstykke 15 fører op til den øverste del 20 af apparatet, der er vist på fig. 5 og 6, og hvori den endelige støvudskilning finder sted. Den øverste del 20 er som vist cylinderformet, idet den koniske ydervæg 16 fra det koniske overgangsstykke 15 (indikeret med punkterede linier på fig. 5) er forlænget opad til dannelse af en ydervæg, der er lukket foroven. Indvendig er den Indre 15 cyfinderflade 2 og dermed midtenummet 4 forlænget et stykke op i den øverste del. Over midterrummet 4 er der i den øverste del 20 anbragt en cylinderformet del 22, der foroven over et stykke af sin omkreds har en åbning med skovlblade 21 og forneden slutter sig til midterrummet 4 ved en rundtgående rende 23.10 The tapered transition piece 15 leads to the upper portion 20 of the apparatus shown in FIG. 5 and 6 and in which the final dust removal takes place. The upper portion 20 is cylindrical as shown, with the tapered outer wall 16 of the tapered transition piece 15 (indicated by dashed lines in Fig. 5) being extended upwardly to form an outer wall closed at the top. Inside, the inner 15 pin-finder surface 2 and thus the middle space 4 are extended slightly up in the upper part. Above the middle compartment 4, a cylindrical part 22 is arranged in the upper part 20, which has an opening above a portion of its circumference, with an opening with blade blades 21, and below it joins the middle compartment 4 by a circumferential gutter 23.

20 Den cylinderformede del 22 udgør en cyklon, idet den opadstrømmende damp med medrevne støvpartikler vil stramme Ind i delen 22 mellem skovlbladene 21, således at der dannes et cyklonfelt Støvpartikler vil samle sig på væggen af den cylinderformede del 22, synke ned langs væggen og rotere rundt i den rundtgående rende 23, indtil de passerer gennem en udløbsåbning 24 (vist på fig. 6) i 25 den rundtgående rende 23. Udløbsåbningen 24 fører til, således som det nærmere er vist i fig. 7, en ejektor 25, som suger støvpartikler og en delstrøm af damp ind i en lodret udløbskonus 26. Ejektøren 25 drives af damp, som tilføres udefra. Udløbskonusen 26 er fortrinsvis placeret oven over udtaget for tørt produkt fra apparatet, det vil sige i området oven over afgangsrøret 6.The cylindrical portion 22 constitutes a cyclone in which the upwardly flowing steam with entrained dust particles will tighten Into the portion 22 between the vane blades 21, thus forming a cyclone field. around the circumferential gutter 23 until they pass through an outlet opening 24 (shown in FIG. 6) in the circumferential gutter 23. The outlet opening 24 leads, as shown in more detail in FIG. 7, an ejector 25 which sucks dust particles and a partial stream of steam into a vertical outlet cone 26. The ejector 25 is driven by steam supplied from outside. The outlet cone 26 is preferably located above the dry product outlet of the apparatus, i.e. in the area above the outlet tube 6.

30 10 DK 173016 B130 10 DK 173016 B1

Skovlbladene 21 for indløb i den cylinderformede del 22 er som vist på fig. 6 fortrinsvis placeret oven over den sidste del af det ringformede kammer 1, det vil sige den del, der er nærmest det område, hvor afgangsrøret 6 er placeret. Dette medfører, at der i den øverste del 20 uden for den cylinderformede del 22 opstår 5 en rundtgående strømning i den opadstigende damp. Denne rundtgående strømning vil passere mellem plader 30, der er udformet som dele af cylinderflader. Ved passagen af disse plader 30 vil noget af den medrevne støvmasse glide ned ad pladerne i et grænselag, således at støvmængden, der føres frem til skovlbladene 21 og den cylinderformede del 22, vil blive reduceret. Den rundt-10 gående strømning vil blive standset af en separatorvæg 7, der er placeret således som vist på fig. 6, hvorefter strømningen vil blive ført ind mellem skovlbiade-ne 21 ind i den cylinderfbrmede del 22.The vane blades 21 for inlet into the cylindrical portion 22 are shown in FIG. 6 is preferably located above the last portion of the annular chamber 1, that is, the portion closest to the region where the outlet tube 6 is located. As a result, in the upper part 20 outside of the cylindrical part 22, 5 there is a circular flow in the rising steam. This circular flow will pass between plates 30, which are formed as parts of cylinder faces. Upon passage of these plates 30, some of the entrained dust mass will slide down the plates in a boundary layer so that the amount of dust conveyed to the vane blades 21 and the cylindrical portion 22 will be reduced. The circular flow will be stopped by a separator wall 7 positioned as shown in FIG. 6, after which the flow will be introduced between the blade surfaces 21 into the cylindrical portion 22.

Dampstrømmen, der er nået ind i den cylinderfbrmede del 22, vil passere I form 15 af en hoveddampstrøm ned gennem mldtenummet 4 som vist med pilen 27. imidlertid vil der ved tørringen af det partikelformede materiale tilføres yderligere damp til strømningen, således at der er et behov for at føre en tilsvarende mængde overskudsdamp bort. Dette sker gennem en åbning 28 foroven i den øverste del 20 af apparatet, således som vist ved pilen 29. Denne overskuds-20 damp indeholder al den energi, der er anvendt til fordampningen. Ved at kondensere overskudsdampen genvinder man såvel energien, der tilbageføres til processen, som væsken, således at separeringen af væske er sket med mindst mulig energiforbrug og uden nogen luftforurening. Endvidere kan ved styring af den bortledte dampmængde styre trykket i det lukkede system, idet der med for-25 del kan arbejdes under et tryk på f. eks. 3 til 4 bar.The vapor stream reached into the cylindrical portion 22 will pass in the form 15 of a main vapor stream down through the flow chamber 4 as shown by arrow 27. However, upon drying the particulate material, additional vapor will be added to the flow so that there is a need to carry a similar amount of excess steam away. This is done through an opening 28 at the top of the upper portion 20 of the apparatus, as shown by arrow 29. This excess vapor contains all the energy used for the evaporation. By condensing the excess steam, both the energy returned to the process and the liquid are recovered, so that the separation of liquid has been done with the least possible energy consumption and without any air pollution. Furthermore, by controlling the discharged vapor volume, the pressure in the closed system can be controlled, with advantage being possible to operate under a pressure of, for example, 3 to 4 bar.

Hoveddampstrømmen, der passerer ned gennem midterrummet 4, vil på sin vej passere en varmeveksler eller overheder (ikke vist), hvorved dampens overhedning øges, således at den får et nyt tørringspotentiale. I bunddelen 9 af appara-30 tet sidder der endvidere en blæser såsom eksempelvis en centrifugalblæser 11 DK 173016 B1 (ikke vist), der sender den overhedede damp op gennem det ringformede tørrekammer 1 igen.The main vapor stream passing down through the center space 4 will, in its path, pass a heat exchanger or superheater (not shown), thereby increasing the superheat of the steam to give it a new drying potential. In addition, in the bottom part 9 of the apparatus there is a fan such as, for example, a centrifugal fan 11 (not shown) which sends the superheated steam through the annular drying chamber 1 again.

Claims

12 DK 173016 B1

A process for removing liquid from particulate material by evaporation through the application of heat substantially transferred by superheated vapor of the liquids contained in the particulate material, which process takes place in a substantially closed system, characterized by: the particulate material is continuously fed to a process chamber having the shape of a substantially horizontal annular or partially annular chamber (1), that the superheated vapors are fed from below through openings (11) into a bottom (10) of the annular chamber so that the particulate material is moved by the superheated vapors and so that the particulate material is transported around the annular chamber (1).

Method according to claim 1, characterized in that the bottom (10) of the annular chamber (1) has a trough-shaped, double-curved or approximately double-curved shape, through which the superheated vapors are directed in controlled directions and a larger flow is conducted. of superheated steam into the annular chamber Near the outside of the chamber than at the inside of the chamber.

Method according to claim 1 or 2, characterized in that a larger flow of superheated vapors is introduced into the annular chamber (1) in the vicinity of a titrated opening (5) for particulate material than in parts of the annular chamber (1). , which is in the vicinity of an outlet opening (6) for the particulate material. 25

Apparatus for carrying out the method according to claim 1, comprising a substantially closed container having means for supplying particulate material from which to remove liquid, means for removing dried particulate material, means for circulating superheated vapors in the container means for supplying 30 heat energy to these vapors and means for separating dust particles from steam.

13 DK 173016 B1, characterized in that the container contains a substantially horizontal process chamber in the form of an annular or partially annular chamber (1), which chamber has a vapor-permeable bottom (10), having openings (11). ) in the bottom (10) that the bottom has a relatively larger opening area near the outside of the annular chamber than near the inner side of the chamber, and a relatively larger opening area near a supply opening (5) for the particulate material than near the outlet opening (6) for the particulate material, and that the openings (11) in the bottom (10) are designed such that steam inflow occurs at right angles to the bottom and partly at angles 10 with the bottom (10) of between 0 ° and 90 °, preferably between 0 ° and 80 ° and especially between 0 ° and 30 ° in different directions, so as to promote a circular motion and a movement in the circumferential direction of the annular chamber of the particulate product

Apparatus according to claim 4, characterized in that the bottom (10) of the annular chamber (1) is formed such that it has a vertical section in a shape where it has a lowest point which lies within the middle half. of the chamber width between an inner and an outer edge of the annular chamber, the bottom (10) of the chamber being of a semicircular shape, an oval shape, or an approximation, optionally in an angular shape, to such shapes.

Apparatus according to claim 4 or 5, characterized in that in the annular chamber (1), plates (13) are projected from the inside (2) and / or from the outside (3) of the annular chamber (1). , which plates are suspended in such a direction and have such a slope and / or bend that an adequate loading of the particulate material into the annular chamber is ensured.

Apparatus according to claim 6, characterized in that the suspended plates (13) in the annular chamber (1) are designed to serve as heating surfaces.

14 DK 173016 B1 for the vapor stream and the particulate material, the plates (13) being optionally formed with voids to which steam can be supplied.

Apparatus according to one or more of claims 4 to 7, characterized in that the apparatus comprises a container part having the form of a conical transition piece (15) arranged in the container above the annular chamber (1) and through which the superheated vapors may flow in which tapered transition piece (15) radiates from an inner wall (2) plates (17) bent or curved forward in the direction of transport of the particulate material, and which plates (17) over at least one part of the length of an outer edge towards a tapered outer wall (16) of the tapered transition piece (15) is spaced from this tapered outer wall (16).

Apparatus according to claim 8, characterized in that the plates (17) radiating from the inner wall (2) of the tapered transition piece (15) serve as heating surfaces for the vapor stream and the particulate material, the plates (17) optionally may be formed with voids to which steam may be supplied.

Apparatus according to one or more of claims 4 to 9, characterized in that the apparatus comprises a cylindrical part (22) disposed at the top of the container which constitutes a cyclone in which a dust extraction from the superheated vapors takes place. before these are brought down to the means for supplying heat energy.