DK148315B - Method and system for utilization of the heat in waste gas from a continuously fired dryer in fishmeal production - Google Patents
Method and system for utilization of the heat in waste gas from a continuously fired dryer in fishmeal production Download PDFInfo
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- DK148315B DK148315B DK547881A DK547881A DK148315B DK 148315 B DK148315 B DK 148315B DK 547881 A DK547881 A DK 547881A DK 547881 A DK547881 A DK 547881A DK 148315 B DK148315 B DK 148315B
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- evaporator
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- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Meat, Egg Or Seafood Products (AREA)
Description
148315148315
Opfindelsen angår en fremgangsmåde og et anlæg til bedre udnyttelse end det hidtil har været tilfældet af varmen i afgas fra en gennemfyringstørrer i fiskemelsfabrikation, hvor afgassen underkastes vask med vand.The invention relates to a method and a plant for better utilization than has hitherto been the case of the heat in the exhaust gas from a furnace drying dryer in fishmeal fabrication, where the exhaust gas is subjected to washing with water.
De senere års kraftige stigninger af brændselspriserne har gjort det nødvendigt at søge udveje for at spare på varmeenergi i industrier med stort varmeforbrug, hvilket f.eks. gælder fremstillingen af fiskemel.In recent years, sharp increases in fuel prices have made it necessary to look for ways to save heat energy in industries with high heat consumption, for example. applies to the manufacture of fishmeal.
Ved fiskemelsfremstilling underkastes råmaterialet en kogning efterfulgt af en presning, hvorved materialet befries for en væsentlig del af sit olie- og vandindhold, hvorefter pressekagen formales og tørres til et vandindhold under 10%. Den afpressede væske separeres i fiskeolie og en vandfase, limvand, der i regelen indeholder 5-10% opløste proteinstoffer, og som for at udnytte disse opkoncentreres til omkring 40% tørstofindhold og derefter tilføres til den formalede pressekage og tørres med denne.In fish meal preparation, the raw material is subjected to boiling followed by a pressing, whereby the material is freed of a substantial part of its oil and water content, after which the press cake is ground and dried to a water content below 10%. The extruded liquid is separated into fish oil and an aqueous phase, glue water which usually contains 5-10% dissolved protein substances and which to utilize these is concentrated to about 40% dry matter content and then fed to the ground press cake and dried with it.
Det største forbrug af varmeenergi i fiskemelsprocessen medgår til tørringen, der enten sker indirekte ved hjælp af kraftdamp eller direkte ved indfyring i tørrerens ene ende. Hovedparten af denne energi er indeholdt i vanddampen, der afgår fra tørregodset sammen med tørreluften eller forbrændingsprodukterne fra fyret, hvis der anvendes direkte fyring, og opfindelsen tager navnlig sigte på at nyttiggøre varmeindholdet i en sådan blanding af vanddamp, tørreluft og forbrændingsprodukter, kaldet afgas.The greatest consumption of heat energy in the fishmeal process is due to the drying, either indirectly by means of vapor steam or directly by firing at one end of the dryer. Most of this energy is contained in the water vapor that emits from the drying property together with the drying air or combustion products of the furnace if direct firing is used, and the invention is particularly aimed at utilizing the heat content of such a mixture of water vapor, drying air and combustion products, called exhaust gas.
I typiske fiskernelsanlæg passerer denne afgas til fjernelse af lugtende bestanddele og kondensation af vanddampen gennem et vasketårn, og til fyret i en dampkedel, som f.eks. kan levere damp til kogningen og til en flertrinsinddamper for limvandet.In typical fishery plants, this exhaust gas passes to remove odorous constituents and condensation of the water vapor through a washing tower, and to the boiler in a steam boiler, such as a steam boiler. can supply steam to the boiling and to a multi-stage evaporator for the glue water.
I henhold til USA patentskrift nr. 4.281.024 kan en del af varmeenergien i afgasserne udnyttes i en ettrinsvask. Den del af varmen, som kan udnyttes, er imidlertid kun den overhedning gasserne har før kondensering begynder, medens kondensationsvarmen i afgassen går tabt.According to United States Patent No. 4,281,024, part of the heat energy in the exhaust gas can be utilized in a one-stage wash. However, the part of the heat that can be utilized is only the superheat of the gases before condensation begins, while the condensation heat in the exhaust gas is lost.
Formålet med opfindelsen er at forbedre varmeøkonomien ved en bedre udnyttelse af varmeenergien i afgassen end det hidtil har været tilfældet, idet den varmeenergi, der tidligere gik tab med vaskevandet ved vask af afgassen, udnyttes 148315 2 på særlig måde.The object of the invention is to improve the heat economy by better utilization of the heat energy in the exhaust gas than has hitherto been used, since the heat energy which was previously lost to the washing water by washing the exhaust gas is utilized in a special way.
Opfindelsen er baseret på den iagttagelse, at varmeafgivelsen fra afgassen ikke er proportional med temperaturfaIdet, men forløber efter en stærkt krummet kurve, således at hovedparten af varmeafgivelsen sker under den første del af afkølingen indenfor et temperaturfald på 15-20°C.The invention is based on the observation that the heat release from the exhaust gas is not proportional to the temperature range, but proceeds according to a strongly curved curve, so that most of the heat release occurs during the first part of the cooling within a temperature drop of 15-20 ° C.
Fremgangsmåden ifølge opfindelsen er derfor ejendommelig ved, at en del af luften, der forlader tørreren, recirkuleres til denne, at vasken af afgassen foretages i to i serie forbundne vasketrin, og at vaskevandet fra det første af disse benyttes til opvarmning af første trin af en flertrinsinddamper for limvand, medens varmeindhold i vaskevandet fra det sidste vasketrin udnyttes i et senere trin af flertrinsinddamperen.The process according to the invention is therefore characterized in that a portion of the air leaving the dryer is recycled thereto, that the washing of the exhaust gas is carried out in two connected washing steps and that the washing water from the first of these is used for heating the first stage of a multistage evaporator for glue water, while heat content in the wash water from the last washing step is utilized in a later step of the multistage evaporator.
Ved første trin af en flertrinsinddamper skal, idet limvandskoncentreringen sker efter modstrømsprincippet, forstås det trin, hvor limvandet færdigkoncentreres.In the first stage of a multi-stage evaporator, since the glue water concentration takes place according to the countercurrent principle, the step in which the glue water is concentrated is understood.
Ved en simpel recirkulering af en del af luften, der forlader tørreren, opnås der to væsentlige fordele, nemlig: 1) Energiforbruget ved tørreprocessen reduceres med ca.By simply recirculating a portion of the air leaving the dryer, two significant benefits are achieved, namely: 1) The energy consumption of the drying process is reduced by approx.
15%.15%.
2) Spildvarmen gøres mere værdifuld, idet "wet bulb" hæves fra ca. 64°C til ca. 82°C.2) The waste heat is made more valuable, raising the "wet bulb" from approx. 64 ° C to approx. 82 ° C.
Ifølge en udførelsesform for fremgangsmåden ifølge opfindelsen cirkuleres vaskevandet, som anvendes i sidste vasketrin mellem dette og en mellembeholder, hvori der afgives damp, som sammen med damp fra en momentanfordamper, limvandet passerer på vej til flertrinsinddamperen, benyttes til opvarmning af et senere trin af flertrinsinddamperen.According to an embodiment of the method according to the invention, the wash water used in the last washing step is circulated between this and an intermediate container, in which steam which, together with steam from a momentary evaporator, passes through the path to the multistage evaporator, is used for heating a later stage of the multistage evaporator. .
Ifølge en anden udførelsesform for fremgangsmåden cirkuleres vaskevandet fra sidste vasketrin mellem dette og en mellembeholder, og damp herfra sammen med damp fra første inddampertrin i en totrinsinddamper og damp fra en momentanfordamper for varmt limvand benyttes til opvarmning af andet inddampertrin i totrinsinddamperen.According to another embodiment of the method, the wash water from the last washing step is circulated between this and an intermediate container, and steam from it together with steam from the first evaporator stage in a two-stage evaporator and steam from a hot glue instantaneous evaporator is used for heating the second evaporator stage in the two-stage evaporator.
Opfindelsen omfatter som tidligere nævnt også et anlæg til udførelse af fremgangsmåden, hvilket anlæg er ejendomme 148315 3 ligt ved to i serie forbundne vasketrin, af hvilke det første er tilsluttet en afgasledning, hvilken afgasledning er udstyret med en blæser og en afgrenet ledning til recirkulation af afgassen fra en fiskemelstørrer og er indrettet for cirkulation af vaskevand mellem første vasketrin og første trin af en flertrinsinddamper og ved en afgasledning er forbundet med det andet vasketrin, som har cirkulationsledning for vaskevandet gennem en mellembeholder, der har en afgangsledning for deri udviklet damp til et senere trin af flertrins inddamperen, hvorhos anlægget er afsluttet med en kondensator.The invention also includes, as mentioned earlier, a plant for carrying out the method, which plant is located at two series of washing steps, the first of which is connected to a gas line, which gas line is provided with a fan and a branched line for recirculating the the exhaust gas from a fishmeal dryer and is arranged for circulation of wash water between the first washing step and the first stage of a multi-stage evaporator and at a gas line is connected to the second washing step, which has circulation line for the wash water through an intermediate container, which has a discharge line for steam developed therein. later stages of the multi-stage evaporator, where the system is terminated with a capacitor.
Ved en udførelsesform for anlægget ifølge opfindelsen er afgasledningen udstyret med blæser og en afgrenet ledning til recirkulation af afgassen, hvorved opnås, at det rumfang af denne, der pr tidsenhed sendes ind i vasketårnssystemet, formindskes, og dets varmeindhold pr rumfangsenhed forhøjes.In one embodiment of the plant according to the invention, the exhaust pipe is equipped with a blower and a branched pipe for recirculating the exhaust gas, thereby obtaining that the volume thereof sent per unit time into the washing tower system is increased and its heat content per unit volume is increased.
En yderligere udførelsesform for anlægget ifølge opfindelsen er ejendommelig ved, at der i en tilførselsledning for varmt limvand til flertrinsinddamperen er indskudt en momentanfordamper med niveauregulering og dampafgang til sidste trin af flertrinsinddamperen.A further embodiment of the system according to the invention is characterized in that in a hot glue water supply line to the multi-stage evaporator a momentary evaporator with level control and vapor outlet is added to the last stage of the multi-stage evaporator.
Opfindelsen skal i det følgende beskrives nærmere under henvisning til tegningen, der i skematiseret form viser en udførelsesform for et anlæg ifølge opfindelsen.BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the drawing, which shows in schematic form an embodiment of a plant according to the invention.
I anlægget indgår en fiskernelstørrer 1 med direkte fyring som antydet ved en pil 2. Det tørrede fiskemel udsluses fra en opsamlingsbeholder 3, og afgas fra tørreren sendes ved hjælp af en blæser 4 gennem en ledning 5, der har en afgrenet ledning 6 til recirkulation af afgas til tørreren 1, til et første vasketårn 7 og derfra gennem en ledning 8 til et andet vasketårn 9, hvorfra den i afkølet stand afgår gennem en ledning 10.The plant includes a direct-firing fishmeal dryer 1 as indicated by an arrow 2. The dried fishmeal is drained from a collection vessel 3, and exhaust gas from the dryer is sent by means of a blower 4 through a conduit 5 having a branched conduit 6 for recycling. is degassed to the dryer 1, to a first washing tower 7 and thence through a conduit 8 to a second washing tower 9, from which it leaves in a cooled state through a conduit 10.
Vasketårnene 7 og 9 kan eventuelt være sammenbygget.The washing towers 7 and 9 may optionally be assembled.
Vaskevandet fra vasketårnet 7 cirkuleres ved hjælp af en pumpe 11 og ledninger 12 og 13 gennem første trin 14 af en totrinsinddamper for limvand til opvarmning af denne og derfra retur til vasketårnet.The wash water from the wash tower 7 is circulated by means of a pump 11 and conduits 12 and 13 through the first stage 14 of a two-stage evaporator for glue water to heat it and then return to the wash tower.
Vaskevandsmængden i tårnet 7 tilføres til stadighed vand ved udkondensering af dampen i afgassen, og derfor er 4 148315 en med ventil udstyret forbindelsesledning indskudt mellem ledningen 13 og en senere beskrevet cirkulationsledning for vaskevandet fra tårnet 9 og tjener til regulering af vaskevandsmængden i tårnet 7.The amount of wash water in the tower 7 is continuously supplied with water by condensing the steam in the exhaust gas, and therefore a valve-connected connection line is inserted between the line 13 and a later described circulation line for the wash water from the tower 9 and serves to control the amount of wash water in the tower 7.
Vaskevandet fra vasketårnet 9 cirkuleres ved hjælp af en pumpe 15 og ledninger 16 og 17 mellem tårnet 9 og en beholder 18, hvorfra damp gennem en ledning 19 kan føres til sidste trin 20 af totrinsinddamperen.The wash water from the wash tower 9 is circulated by means of a pump 15 and conduits 16 and 17 between the tower 9 and a container 18, from which steam through a conduit 19 can be passed to the last step 20 of the two-stage evaporator.
Alt efter hvor varmt limvandet er, tilføres det gennem en ledning 21 med trevejsventil 22 enten direkte til sidste trin 20 af totrinsinddamperen 14,20, eller hvis det er meget varmt,passerer det undervejs en momentanfordamper 23, niveauet i hvilken reguleres ved hjælp af en ventil 24 indskudt i en med en pumpe 25 udstyret ledning 26 til inddampertrinet 20.Depending on how hot the glue water is, it is supplied through a conduit 21 with three-way valve 22 either directly to the last stage 20 of the two-stage evaporator 14,20, or if it is very hot, it passes a momentary evaporator 23, the level at which is controlled by a valve 24 inserted into a conduit 26 equipped with a pump 25 for the evaporator stage 20.
En cirkulationsledning 27 med pumpe 28 cirkulerer limvandet gennem inddampertrinet 20,og en anden ledning 29 med pumpe 30 fører det forkoncentrerede limvand til inddampertrinet 14, der ligeledes er udstyret med cirkulationsledning 31 med pumpe 32 for cirkulation af limvandet, indtil dette er opkoncentreret så meget som muligt. Det færdige koncentrat udtages gennem en ledning 33 med pumpe 34.A circulation line 27 with pump 28 circulates the glue water through the evaporator stage 20, and a second line 29 with pump 30 leads the preconcentrated glue water to the evaporator stage 14, which is also equipped with circulation line 31 with pump 32 for circulating the glue water until it is concentrated as much as possible. The finished concentrate is withdrawn through a conduit 33 with pump 34.
Den ved limvandskoncentreringen i trin 14 udviklede damp føres gennem en ledning 35 til en ledning 36 for bortgående damp fra momentanfordamperen 23, og ledningen 36 sluttes til ledningen 19 fra beholderen 18, således at også damp fra ledningerne 35 og 36 udnyttes i inddampertrinet 20.The steam generated at the glue water concentration in step 14 is passed through a conduit 35 to a conduit 36 for evaporating steam from the instantaneous evaporator 23, and conduit 36 is connected to conduit 19 from container 18 so that steam from conduits 35 and 36 is also utilized in evaporator stage 20.
Endvidere passerer kondensvand fra inddampertrinet 14 gennem en ledning 37 til inddampertrinet 20 og afgiver her en del af sin varme, før det sammen med i trinet 20 dannet kondensatvand bortpumpes fra inddampertrinet 20 gennem en kondensvandsledning 38.Further, condensation water passes from evaporator stage 14 through a conduit 37 to evaporator stage 20 and discharges a portion of its heat before being pumped away from the evaporator stage 20 through a condensation water line 38 together with the condensate water 20.
Systemet evakueres gennem en ledning 39 til en kondensator 40, der opretholder det for fordampningen nødvendige vakuum.The system is evacuated through a conduit 39 to a capacitor 40 which maintains the vacuum required for evaporation.
Claims (5)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DK547881A DK148315B (en) | 1981-12-10 | 1981-12-10 | Method and system for utilization of the heat in waste gas from a continuously fired dryer in fishmeal production |
NO824155A NO824155L (en) | 1981-12-10 | 1982-12-09 | PROCEDURE AND FACILITIES OF Utilization of Heat in Exhaust Gas from a Fishmeal Dryer |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DK547881 | 1981-12-10 | ||
DK547881A DK148315B (en) | 1981-12-10 | 1981-12-10 | Method and system for utilization of the heat in waste gas from a continuously fired dryer in fishmeal production |
Publications (2)
Publication Number | Publication Date |
---|---|
DK547881A DK547881A (en) | 1983-06-11 |
DK148315B true DK148315B (en) | 1985-06-10 |
Family
ID=8142780
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DK547881A DK148315B (en) | 1981-12-10 | 1981-12-10 | Method and system for utilization of the heat in waste gas from a continuously fired dryer in fishmeal production |
Country Status (2)
Country | Link |
---|---|
DK (1) | DK148315B (en) |
NO (1) | NO824155L (en) |
-
1981
- 1981-12-10 DK DK547881A patent/DK148315B/en not_active Application Discontinuation
-
1982
- 1982-12-09 NO NO824155A patent/NO824155L/en unknown
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Publication number | Publication date |
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DK547881A (en) | 1983-06-11 |
NO824155L (en) | 1983-06-13 |
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