WO1989005949A1 - Industrial installation for drying a moist product with at least partial recirculation of a drying fluid - Google Patents
Industrial installation for drying a moist product with at least partial recirculation of a drying fluid Download PDFInfo
- Publication number
- WO1989005949A1 WO1989005949A1 PCT/FR1987/000514 FR8700514W WO8905949A1 WO 1989005949 A1 WO1989005949 A1 WO 1989005949A1 FR 8700514 W FR8700514 W FR 8700514W WO 8905949 A1 WO8905949 A1 WO 8905949A1
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- WO
- WIPO (PCT)
- Prior art keywords
- enclosure
- drying
- installation according
- heat exchangers
- box
- Prior art date
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B17/00—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement
- F26B17/02—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces
- F26B17/08—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces the belts being arranged in a sinuous or zig-zag path
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B25/00—Details of general application not covered by group F26B21/00 or F26B23/00
- F26B25/06—Chambers, containers, or receptacles
Definitions
- the invention relates to an industrial installation for drying a wet product, of the type with at least partial recirculation of a drying fluid, such as air or superheated steam, with possible mechanical recompression of the drying fluid in the case of water vapor.
- a drying fluid such as air or superheated steam
- Such an installation is applicable to the drying of the most diverse products, which are in bulk, in the form of more or less moist pieces or pastes, and finds a particularly advantageous application in sweets, for the drying of beet pulp.
- Processes and installations have been known for drying a wet product by recirculation and mechanical recompression of a constant flow of water vapor.
- a chamber in which the water vapor flow circulates, is crossed by a flow of wet product. Part of the water from the wet product is absorbed by the water vapor which comes into contact with the wet product.
- the latter is heated to then return to contact with the wet product in the enclosure and charge again with humidity, while the steam supplied by the compressor is condensed and then evacuated.
- This process has the advantage of consuming only the energy necessary for the operation of the compressor and the fans for circulating the water vapor flow, as well as for compensating for heat losses.
- the implementation of this process poses significant technical problems and the known installations of this type are generally very bulky and have a complex and costly structure, in an attempt to satisfy a certain number of conditions such as sealing. , corrosion resistance, and resistance to very high differential thermal stresses.
- the object of the invention is in particular to provide a simple and effective at these problems.
- a wet product of the type with at least partial recirculation of a drying fluid
- an enclosure with a modular structure equipped with conveyor belts for moving the product, fans. for circulating a flow rate of drying fluid in the enclosure, means for withdrawing a fraction of this flow rate, and heat exchangers traversed by the remaining fraction of the flow rate of drying fluid, characterized in that said enclosure comprises a lower part formed by a rigidified box with a rectangular cross section supporting the fans, the heat exchangers and the framework of an upper part having substantially the shape of a cylinder portion which covers the upper face of the box and is connected to it and which surrounds the conveyors and the heat exchangers.
- the largest masses (fans, heat exchangers, framework and conveyors) are supported by the lower box, whose structure is specially designed to withstand such a load, while the shape substantially cylindrical from the upper part of the enclosure allows it to better resist the internal pressure of the drying fluid exiting the fans.
- the fans are supported directly by the lower part of the enclosure and no longer fixed to a structure external to the enclosure and connected to the latter by means which must withstand significant differential thermal stresses.
- the planar shape of the walls of the lower enclosure of the enclosure facilitates the fixing of the flanges of the fans on these walls.
- the upper part of the enclosure comprises two vertically superposed conveyors and means for transferring the product from one end of the upper conveyor to the corresponding end of the lower conveyor, a partition wall being provided between the conveyors over their entire length to delimit in the enclosure an upper drying zone comprising the upper conveyor and crossed by a first flow of drying fluid, a lower drying zone comprising the lower conveyor and crossed by a second flow of fluid and a zone for mixing these two flows leaving the drying zones, which is connected to the lower box upstream of the fans.
- the fans are supplied by a single flow of drying fluid having a substantially constant temperature.
- the fans are axial fans which are oriented transversely and supported at the same level by the lower box of the enclosure, over the entire length thereof, and which are connected to the faces d entry of the heat exchangers through transverse diffusers housed in the lower box and extending over substantially the entire width of the conveyors.
- These axial fans are much less bulky than centrifugal fans and can therefore be mounted at the same level on the lower box, to be fed by the flow resulting from the mixture of the two drying fluid flows leaving the two aforementioned drying zones.
- the lower part of the box rests on a fixed support structure by means of sliding pads allowing longitudinal and transverse movement of the ends of the box relative to its fixed center. , under the effect of differential thermal expansions of the enclosure.
- This arrangement avoids the appearance of unacceptable stresses in the areas of attachment of the enclosure to a fixed support structure.
- the fraction taken from the water vapor flow rate which corresponds to the amount of water evaporated from the product, is supplied to a compressor which supplies the heat exchangers.
- the invention provides that the compressor supplying the heat exchangers is for example of the two-stage type, and that it is connected to the exchangers by finned diffusers. This technical solution allows direct adaptation of the compressor operation to variations in the operating conditions of the installation and the delivery of a substantially constant outlet pressure.
- the compressor is supplied with water vapor by a separator, which makes it possible to separate and extract the product particles contained in the fraction taken from the water vapor flow rate.
- the means for sampling this fraction of the water vapor flow are provided in the part of the lower casing, which is located under the heat exchangers.
- the enclosure consists of modular elements which are assembled longitudinally end at the end and which each comprise a lower box and an upper part substantially in the portion of a cylinder, the latter being formed by sheets with longitudinal stiffeners and by transverse profiles curved in an arch on which the sheets are welded, the modular elements being fixed to each other by their curved end profiles.
- This modular design of the enclosure facilitates its assembly and assembly.
- FIG. 2 schematically shows the arrangement of conveyors in the enclosure of a drying installation according to the invention
- FIG. 3 is a schematic cross-sectional view of an installation according to the invention
- FIG. 4 is a cross-sectional view of an embodiment of the installation enclosure.
- FIG. 1 illustrates the process for drying a wet product by recirculation and recompression of water vapor.
- An enclosure 10 containing conveyors 12 for moving a layer of wet product is traversed by a substantially constant flow Q of water vapor which has been superheated by passing through a heat exchanger 14.
- the wet product is brought into the enclosure at one end of it, as indicated by arrow 15, is moved on the conveyors
- a large fraction of the water contained in the product is evaporated by heat exchange with the recirculating water vapor and is entrained towards l inlet of a ventilator 18.
- a fraction q of the vapor flow rate corresponding to the quantity of water evaporated from the product, is taken through a conduit 20, this flow q is passed through a separator 22 allowing d 'extract the entrained product particles, and compri ⁇ me, by means of a compressor 2k, this flow q to supply the heat exchanger 14.
- the water vapor leaving the fan 18 is superheated in the exchanger 14.
- the energy consumption is limited to the energy consumption necessary for driving the fan 18 and the compressor 24, and for compensating for the heat losses.
- FIG. 2 schematically represents the arrangement of the conveyors 12 in the enclosure 10.
- a feed hopper 28, equipped with a lock 30 allows a sealed supply of wet product 32 into the enclosure 10 and the deposition of a layer 34 of wet product on one end of the upper conveyor 12.
- the product is discharged on an inclined plane 36 which brings it to the corresponding end of the lower conveyor 12.
- the dried product is collected in an outlet hopper, of the same type as the inlet hopper 28, and is led outside the enclosure 10.
- the conveyor belts 12 are constituted by a stainless steel mesh with relatively fine mesh, so that the drying fluid can pass through the layers of product carried by these belts without entraining particles of product having a large size.
- Figure 3 schematically shows a cross section of the enclosure of an installation according to the invention.
- This enclosure is of modular structure, as will be seen below, and is formed of elements assembled end to end and each having the cross section shown in Figure 3.
- Each modular element comprises a lower part formed by a rectangular parallelepiped box 40 which carries the heat exchangers 14, the fans 18 and the framework of the upper part 42 of the modular element, which is constituted by a substantially cylindrical envelope with elliptical section covering the upper face of the box 40 and connected to the latter tightly.
- the internal framework of this modular element consists of three vertical longitudinal walls 44, 46 and 48 and horizontal floors 50, 52 and 54.
- the conveyors 12 represented in FIG. 3 by lines in dotted lines, are supported by this framework and extend between the vertical walls 44 and 46 being contained inside the envelope 42, that is to say between the intermediate floor 52 and the upper floor 54.
- An oblique floor 56 is mounted on the walls vertical 44 and 46 so as to share the space between the two conveyors 12.
- the heat exchangers 14 are carried by the intermediate floor 52, between the vertical walls 46 and 48, the upper part of which carries means 58 for lifting a battery of exchangers such as, for example, a traveling crane.
- the fans 18 are arranged in the lower box 40 and are carried by the lower part of the vertical wall 44. Each fan 18 is driven by an electric motor 50 which is located outside the enclosure and is supported by the part bottom of the vertical wall 44.
- a transverse and horizontal diffuser 60 extends inside the lower box 40, between the impeller of each fan and the intermediate vertical wall 46, and is connected to the inlet face of the exchangers 14 by fixed guide vanes 62 housed in the lower box 40, between the vertical walls 46 and 48 of the frame.
- the arrows in FIG. 3 illustrate the circulation of the drying fluid in the enclosure: the drying fluid leaving the diffusers 60 passes through the heat exchangers 14 and is divided into two flows, one of which crosses the upper conveyor 12 and of which the other, circulating under the oblique floor 56, crosses the lower conveyor 12, these two flows mixing one with the other upstream of the fans 18 and the inlets of the diffusers 60. Because of this mixture of the flows leaving the two conveyors, the temperature upstream of the fans is substantially constant over the entire length of the enclosure.
- the fans 18 arranged at the same level in the lower box 40 are axial fans, for reasons of space.
- Each modular element comprises for example two fans 18 each delivering a relatively high static pressure, and each driven directly by an electric motor 59.
- the diffusers 60 have a length which corresponds substantially to the width of the conveyors 12, and which is for example of the order of five meters.
- the compressor 24 of the Installation feeds by a finned diffuser, a battery of several bundles of finned tubes which are superimposed and connected in series and in which the tubes are oriented transversely to the longitudinal direction of the enclosure and are slightly inclined downwards, to allow the evacuation of condensates.
- the lowest points of the manifolds of the various bundles of finned tubes are connected, for the evacuation of condensates, to the high pressure inlet of a collecting flask situated outside the enclosure.
- the outlet of this collecting tank can be connected to an expansion valve, allowing the pressure of the condensates to be reduced to ambient atmospheric pressure.
- the compressor 24 supplied by the separator 22 is for example a two-stage compressor, fitted at the outlet of. finned diffusers allowing adaptation of the steam flow rate without recycling by the anti-pumping line of the compressor.
- the discharge pressure of the compressor is thus substantially constant throughout the range of variations in the steam flow rate.
- the box 40 forming the lower part of the enclosure and carrying the fans and the heat exchangers, consists of flat sheets provided with stiffeners, and is stiffened by a large number of crosspieces, side members and cross-pieces.
- the upper part 42 of the enclosure is made up of flat sheets provided with longitudinal stiffeners and welded to transverse profiles which are curved in arches in the direction of their greatest inertia.
- the assembly of two consecutive modular elements is done by bringing together and bolting the transverse end profiles of these two elements.
- the sheets are then welded edge to edge on the inside, by continuous welds, each sheet having been previously fixed by a discontinuous weld on the transverse bent profile corresponding.
- An installation according to the invention can consist of six modular elements assembled end to end, to have a total length of about thirty meters, a width of twelve meters and a height of twelve meters.
- the entire installation rests on a fixed support structure, by means of sliding pads which allow a longitudinal and transverse movement of the end parts of the lower box 40, relative to the center of this box which remains fixed. .
- This arrangement makes it possible to absorb the differential thermal expansions of the enclosure, which can be relatively large.
- the flow rate Q of water vapor is between 700 and 1,500 tonnes / hour depending on the pressure of compressor discharge chosen.
- the flow rate q of steam withdrawn to supply the compressor 24 is of the order of 20 tonnes per hour and is supplied by the compressor 24 to the heat exchangers 14 at a temperature of the order of 150 ° C. and a pressure of the order of 4 to 5 bars.
- the enclosure is supplied with a flow rate of approximately 28 tonnes per hour of wet beet pulp at a temperature of 50 ° C., which leaves the enclosure with a dry matter content of the order of 90%. Energy consumption is around 180 kWh per tonne of water evaporated.
- the pressure in the drying installation remains very close to atmospheric pressure. This is achieved by means of a permanent vent connecting part of the installation (for example the area under the conveyors) with the outside.
- the overall thermal surplus of the dryer + compressor system leads to a slight vapor leak preventing air from entering through this permanent vent.
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- General Engineering & Computer Science (AREA)
- Drying Of Solid Materials (AREA)
Abstract
An industrial installation for drying a moist product comprises an enclosure in which a flow of moist product and a flow of drying fluid circulate. The enclosure comprises a lower rigidified caisson (40) which carries the heat-exchangers (14), the fans (18) for circulating the drying fluid, and the framework of an upper part (42) consisting of portion of a cylinder which covers the upper face of the lower caisson (40) and surrounds the conveyors (12) which transport the product to be dried and the heat-exchangers (14). The invention is particularly useful for drying beetroot pulp using super-heated steam.
Description
INSTALLATION INDUSTRIELLE DE SECHAGE D'UN PRODUIT HUMIDE, INDUSTRIAL PLANT FOR DRYING A WET PRODUCT,
DU TYPE A RECIRCULATION AU MOINS PARTIELLEAT LEAST PARTIAL RECIRCULATION TYPE
D'UN FLUIDE DE SECHAGEOF A DRYING FLUID
L'invention concerne une installation industrielle de séchage d'un pro¬ duit humide, du type à recirculation au moins partielle d'un fluide de séchage, tel que de l'air ou de la vapeur d'eau surchauffée, avec éventuelle¬ ment une recompression mécanique du fluide de séchage lorsqu'il s'agit de vapeur d'eau.The invention relates to an industrial installation for drying a wet product, of the type with at least partial recirculation of a drying fluid, such as air or superheated steam, with possible mechanical recompression of the drying fluid in the case of water vapor.
Une telle installation est applicable au séchage de produits les plus divers, se présentant en vrac, sous forme de morceaux ou de pâtes plus ou moins humides, et trouve une application particulièrement intéressante dans les sucreries, pour le séchage de la pulpe de betterave. On connaît depuis longtemps des procédés et des installations de séchage d'un produit humide par recirculation et recompression mécanique d'un débit constant de vapeur d'eau. Une enceinte dans laquelle circule le débit de vapeur d'eau, est traversée par un débit de produit humide. Une partie de l'eau du produit humide est absorbée par la vapeur d'eau qui vient au contact du produit humide. Une fraction du débit de vapeau d'eau, correspondant à la quantité d'eau évaporée du produit est prélevée pour alimenter un compresseur dont la sortie est reliée à un échangeur de chaleur traversé par la fraction restante du débit de vapeur d'eau. Cette dernière est chauffée pour revenir ensuite au contact du produit humide dans l'enceinte et se charger à nouveau d'humidité, tandis que la vapeur fournie par le compresseur est condensée et ensuite évacuée. Ce procédé présente l'avantage de ne consommer que l'énergie nécessaire au fonctionnement du compresseur et des ventilateurs de circulation du débit de vapeur d'eau, ainsi qu'à la compensation des pertes thermiques. La mise en œuvre de ce procédé pose toutefois des problèmes techni¬ ques importants et les installations connues de ce type sont en général très encombrantes et ont une structure complexe et coûteuse, pour tenter de satisfaire à un certain nombre de conditions telles que l'étanchéité, la résistance à la corrosion, et la résistance à des contraintes thermiques différentielles très élevées.Such an installation is applicable to the drying of the most diverse products, which are in bulk, in the form of more or less moist pieces or pastes, and finds a particularly advantageous application in sweets, for the drying of beet pulp. Processes and installations have been known for drying a wet product by recirculation and mechanical recompression of a constant flow of water vapor. A chamber in which the water vapor flow circulates, is crossed by a flow of wet product. Part of the water from the wet product is absorbed by the water vapor which comes into contact with the wet product. A fraction of the water vapor flow rate, corresponding to the quantity of water evaporated from the product, is taken to supply a compressor, the outlet of which is connected to a heat exchanger through which the remaining fraction of the water vapor flow rate passes. The latter is heated to then return to contact with the wet product in the enclosure and charge again with humidity, while the steam supplied by the compressor is condensed and then evacuated. This process has the advantage of consuming only the energy necessary for the operation of the compressor and the fans for circulating the water vapor flow, as well as for compensating for heat losses. The implementation of this process, however, poses significant technical problems and the known installations of this type are generally very bulky and have a complex and costly structure, in an attempt to satisfy a certain number of conditions such as sealing. , corrosion resistance, and resistance to very high differential thermal stresses.
L'invention a notamment pour but d'apporter une solution simple et
efficace à ces problèmes.The object of the invention is in particular to provide a simple and effective at these problems.
Elle propose à cet effet une installation industrielle de séchage d'un produit humide, du type à recirculation au moins partielle d'un fluide de séchage, comprenant une enceinte à structure modulaire équipée de con- voyeurs à tapis de déplacement du produit, des ventilateurs de circulation d'un débit de fluide de séchage dans l'enceinte, des moyens de prélèvement d'une fraction de ce débit, et des échangeurs de chaleur traversés par la fraction restante du débit de fluide de séchage, caractérisée en que ladite enceinte comporte une partie inférieure formée par un caisson rigidifié à section transversale rectangulaire supportant les ventilateurs, les échan¬ geurs de chaleur et l'ossature d'une partie supérieure ayant sensiblement la forme d'une portion de cylindre qui recouvre la face supérieure du caisson et est raccordée à celle-ci et qui entoure les convoyeurs et les échangeurs de chaleur. Grâce à cette structure particulière de l'invention, les masses les plus importantes (ventilateurs, échangeurs de chaleur, ossature et convoyeurs) sont supportés par le caisson inférieur, dont la structure est spécialement conçue pour résister à une telle charge, tandis que la forme sensiblement cylindrique de la partie supérieure de l'enceinte lui permet de résister au mieux à la pression interne du fluide de séchage sortant des ventilateurs. En outre, les ventilateurs sont supportés directement par la partie inférieure de l'enceinte et non plus fixés à une structure extérieure à l'enceinte et raccordés à celle-ci par des moyens devant résister à des contraintes thermiques différentielles importantes. Par ailleurs, la forme plane des parois du caisson inférieur de l'enceinte facilite la fixation des brides des ventilateurs sur ces parois.To this end, it offers an industrial installation for drying a wet product, of the type with at least partial recirculation of a drying fluid, comprising an enclosure with a modular structure equipped with conveyor belts for moving the product, fans. for circulating a flow rate of drying fluid in the enclosure, means for withdrawing a fraction of this flow rate, and heat exchangers traversed by the remaining fraction of the flow rate of drying fluid, characterized in that said enclosure comprises a lower part formed by a rigidified box with a rectangular cross section supporting the fans, the heat exchangers and the framework of an upper part having substantially the shape of a cylinder portion which covers the upper face of the box and is connected to it and which surrounds the conveyors and the heat exchangers. Thanks to this particular structure of the invention, the largest masses (fans, heat exchangers, framework and conveyors) are supported by the lower box, whose structure is specially designed to withstand such a load, while the shape substantially cylindrical from the upper part of the enclosure allows it to better resist the internal pressure of the drying fluid exiting the fans. In addition, the fans are supported directly by the lower part of the enclosure and no longer fixed to a structure external to the enclosure and connected to the latter by means which must withstand significant differential thermal stresses. Furthermore, the planar shape of the walls of the lower enclosure of the enclosure facilitates the fixing of the flanges of the fans on these walls.
Selon une autre caractéristique de l'invention, la partie supérieure de l'enceinte comprend deux convoyeurs verticalement superposés et des moyens de transfert du produit d'une extrémité du convoyeur supérieur à l'extrémité correspondante du convoyeur inférieur, une paroi de séparation étant prévue entre les convoyeurs sur toute leur longueur pour délimiter dans l'enceinte une zone supérieure de séchage comprenant le convoyeur supérieur et traversée par un premier flux de fluide de séchage, une zone inférieure de séchage comprenant le convoyeur inférieur et traversée par un second flux de fluide de séchage, et une zone de mélange de ces deux flux sortant des zones de séchage, qui est raccordée au caisson inférieur en amont des ventilateurs.
De cette façon, et bien que l'enceinte comprenne deux zones de séchage successives, les ventilateurs sont alimentés par un seul flux de fluide de séchage ayant une température sensiblement constante.According to another characteristic of the invention, the upper part of the enclosure comprises two vertically superposed conveyors and means for transferring the product from one end of the upper conveyor to the corresponding end of the lower conveyor, a partition wall being provided between the conveyors over their entire length to delimit in the enclosure an upper drying zone comprising the upper conveyor and crossed by a first flow of drying fluid, a lower drying zone comprising the lower conveyor and crossed by a second flow of fluid and a zone for mixing these two flows leaving the drying zones, which is connected to the lower box upstream of the fans. In this way, and although the enclosure comprises two successive drying zones, the fans are supplied by a single flow of drying fluid having a substantially constant temperature.
Selon une autre caractéristique de l'invention, les ventilateurs sont des ventilateurs axiaux qui sont orientés transversalement et supportés à un même niveau par le caisson inférieur de l'enceinte, sur toute la longueur de celui-ci, et qui sont raccordés aux faces d'entrée des échangeurs de chaleur par des diffuseurs transversaux logés dans le caisson inférieur et s'étendant sur sensiblement toute la largeur des convoyeurs. Ces ventilateurs axiaux sont beaucoup moins encombrants que des ventilateurs centrifuges et peuvent donc être montés au même niveau sur le caisson inférieur, pour être alimentés par le flux résultant du mélange des deux flux de fluide de séchage sortant des deux zones précitées de séchage.According to another characteristic of the invention, the fans are axial fans which are oriented transversely and supported at the same level by the lower box of the enclosure, over the entire length thereof, and which are connected to the faces d entry of the heat exchangers through transverse diffusers housed in the lower box and extending over substantially the entire width of the conveyors. These axial fans are much less bulky than centrifugal fans and can therefore be mounted at the same level on the lower box, to be fed by the flow resulting from the mixture of the two drying fluid flows leaving the two aforementioned drying zones.
Selon encore une autre caractéristique de l'invention, la partie infé- rieure du caisson repose sur une structure de support fixe par l'intermédiaire de patins de glissement autorisant un déplacement longitudinal et transver¬ sal des extrémités du caisson par rapport à son centre fixe, sous l'effet des dilatations thermiques différentielles de l'enceinte.According to yet another characteristic of the invention, the lower part of the box rests on a fixed support structure by means of sliding pads allowing longitudinal and transverse movement of the ends of the box relative to its fixed center. , under the effect of differential thermal expansions of the enclosure.
Ce montage évite l'apparition de contraintes inacceptables dans les zones de fixation de l'enceinte à une structure de support fixe.This arrangement avoids the appearance of unacceptable stresses in the areas of attachment of the enclosure to a fixed support structure.
Lorsque le fluide de séchage est de la vapeur, la fraction prélevée du débit de vapeur d'eau, qui correspond à la quantité d'eau évaporée du produit, est amenée à un compresseur qui alimente les échangeurs de chaleur. Dans ce cas, l'invention prévoit que le compresseur alimentant les échangeurs de chaleur est par exemple du type à deux étages, et qu'il est raccordé aux échangeurs par des diffuseurs à ailettes. Cette solution technique permet une adaptation directe du fonctionnement du compresseur aux variations des conditions de fonctionnement de l'installation et la délivrance d'une pression de sortie sensiblement constante.When the drying fluid is steam, the fraction taken from the water vapor flow rate, which corresponds to the amount of water evaporated from the product, is supplied to a compressor which supplies the heat exchangers. In this case, the invention provides that the compressor supplying the heat exchangers is for example of the two-stage type, and that it is connected to the exchangers by finned diffusers. This technical solution allows direct adaptation of the compressor operation to variations in the operating conditions of the installation and the delivery of a substantially constant outlet pressure.
Avantageusement, le compresseur est alimenté en vapeur d'eau par un séparateur, qui permet de séparer et d'extraire les particules de produit contenues dans la fraction prélevée du débit de vapeur d'eau.Advantageously, the compressor is supplied with water vapor by a separator, which makes it possible to separate and extract the product particles contained in the fraction taken from the water vapor flow rate.
Selon une autre caractéristique de l'invention, les moyens de prélève¬ ment de cette fraction du débit de vapeur d'eau sont prévus dans la partie du caisson inférieur, qui est située sous les échangeurs de chaleur.According to another characteristic of the invention, the means for sampling this fraction of the water vapor flow are provided in the part of the lower casing, which is located under the heat exchangers.
Selon un mode de réalisation préféré de l'invention, l'enceinte est constituée d'éléments modulaires qui sont assemblés longitudinalement bout
à bout et qui comprennent chacun un caisson inférieur et une partie supérieure sensiblement en portion de cylindre, cette dernière étant formée par des tôles à raidisseurs longitudinaux et par des profilés transversaux cintrés en arceau sur lesquels sont soudées les tôles, les éléments modulaires étant fixés les uns aux autres par leurs profilés cintrés d'extrémité.According to a preferred embodiment of the invention, the enclosure consists of modular elements which are assembled longitudinally end at the end and which each comprise a lower box and an upper part substantially in the portion of a cylinder, the latter being formed by sheets with longitudinal stiffeners and by transverse profiles curved in an arch on which the sheets are welded, the modular elements being fixed to each other by their curved end profiles.
Cette conception modulaire de l'enceinte facilite son montage et son assemblage.This modular design of the enclosure facilitates its assembly and assembly.
D'autres caractéristiques, détails et avantages de l'invention apparaî¬ tront plus clairement à la lecture de la description qui va suivre, faite à titre d'exemple en référence aux dessins annexés, dans lesquels :Other characteristics, details and advantages of the invention will appear more clearly on reading the description which follows, given by way of example with reference to the appended drawings, in which:
- la figure 1 illustre schématiquement le procédé de séchage mis en œuvre par l'invention ;- Figure 1 schematically illustrates the drying process implemented by the invention;
- la figure 2 représente schématiquement la disposition des convoyeurs dans l'enceinte d'une installation de séchage selon l'invention ; - la figure 3 est une vue schématique en coupe transversale d'une installa¬ tion selon l'invention ;- Figure 2 schematically shows the arrangement of conveyors in the enclosure of a drying installation according to the invention; - Figure 3 is a schematic cross-sectional view of an installation according to the invention;
- la figure 4 est une vue en coupe transversale d'un mode de réalisation de l'enceinte de l'installation.- Figure 4 is a cross-sectional view of an embodiment of the installation enclosure.
On se réfère d'abord à la figure 1, qui illustre le procédé de séchage d'un produit humide par recirculation et recompression de vapeur d'eau.Reference is first made to FIG. 1, which illustrates the process for drying a wet product by recirculation and recompression of water vapor.
Une enceinte 10 contenant des convoyeurs 12 de déplacement d'une couche de produit humide, est traversée par un débit Q sensiblement constant de vapeur d'eau qui a été surchauffée par traversée d'un échangeur de chaleur 14. Le produit humide est amené dans l'enceinte à une extrémité de celle-ci, comme indiqué par la flèche 15, est déplacé sur les convoyeursAn enclosure 10 containing conveyors 12 for moving a layer of wet product, is traversed by a substantially constant flow Q of water vapor which has been superheated by passing through a heat exchanger 14. The wet product is brought into the enclosure at one end of it, as indicated by arrow 15, is moved on the conveyors
12 et sort de l'enceinte comme indiqué par la flèche 16. Dans l'enceinte 10, une fraction importante de l'eau contenue dans le produit est évaporée par échange de chaleur avec la vapeur d'eau en recirculation et est entraînée vers l'entrée d'un ventilateur 18. En amont du ventilateur, on prélève par un conduit 20 une fraction q du débit de vapeur, correspondant à la quantité d'eau évaporée du produit, on fait passer ce débit q dans un séparateur 22 permettant d'en extraire les particules de produit entraînées, et on compri¬ me, au moyen d'un compresseur 2k, ce débit q pour alimenter l'echangeur de chaleur 14. La vapeur d'eau sortant du ventilateur 18 est surchauffée dans l'echangeur 14. tandis que le débit de vapeur comprimée alimentant cet échangeur est condensé et peut être recueilli sous forme liquide dans une bâche 26. Comme le débit q de vapeur d'eau prélevé en amont du ventilateur
18 correspond à la quantité d'eau évaporée du produit dans l'enceinte 10, le débit Q de vapeur d'eau qui est amené à l'enceinte 10 reste sensiblement constant.12 and leaves the enclosure as indicated by the arrow 16. In the enclosure 10, a large fraction of the water contained in the product is evaporated by heat exchange with the recirculating water vapor and is entrained towards l inlet of a ventilator 18. Upstream of the ventilator, a fraction q of the vapor flow rate, corresponding to the quantity of water evaporated from the product, is taken through a conduit 20, this flow q is passed through a separator 22 allowing d 'extract the entrained product particles, and compri¬ me, by means of a compressor 2k, this flow q to supply the heat exchanger 14. The water vapor leaving the fan 18 is superheated in the exchanger 14. while the flow of compressed steam supplying this exchanger is condensed and can be collected in liquid form in a tank 26. Like the flow q of water vapor taken upstream of the fan 18 corresponds to the quantity of water evaporated from the product in the enclosure 10, the flow rate Q of water vapor which is brought to the enclosure 10 remains substantially constant.
La consommation en énergie est limitée aux consommations d'énergie nécessaires à l'entraînement du ventilateur 18 et du compresseur 24, et à la compensation des pertes thermiques.The energy consumption is limited to the energy consumption necessary for driving the fan 18 and the compressor 24, and for compensating for the heat losses.
La figure 2 représente schématiquement l'agencement des convoyeurs 12 dans l'enceinte 10. Une trémie d'alimentation 28, équipée d'une écluse 30 permet une amenée étanche de produit humide 32 dans l'enceinte 10 et le dépôt d'une couche 34 de produit humide sur une extrémité du convoyeur supérieur 12. A l'extrémité opposée de ce convoyeur, le produit est déversé sur un plan incliné 36 qui l'amène sur l'extrémité correspondante du convoyeur inférieur 12. A l'extrémité opposée de celui-ci, le produit séché est recueilli dans une trémie de sortie, du même type que la trémie d'entrée 28, et est conduit à l'extérieur de l'enceinte 10.FIG. 2 schematically represents the arrangement of the conveyors 12 in the enclosure 10. A feed hopper 28, equipped with a lock 30 allows a sealed supply of wet product 32 into the enclosure 10 and the deposition of a layer 34 of wet product on one end of the upper conveyor 12. At the opposite end of this conveyor, the product is discharged on an inclined plane 36 which brings it to the corresponding end of the lower conveyor 12. At the opposite end of the latter, the dried product is collected in an outlet hopper, of the same type as the inlet hopper 28, and is led outside the enclosure 10.
Les tapis des convoyeurs 12 sont constitués par un treillis en acier inoxydable à mailles relativement fines, de telle sorte que le fluide de séchage puisse traverser les couches de produit portées par ces tapis sans entraîner de particules de produit ayant une taille importante. On se réfère maintenant à la figure 3, qui représente schématiquement une coupe transversale de l'enceinte d'une installation selon l'invention.The conveyor belts 12 are constituted by a stainless steel mesh with relatively fine mesh, so that the drying fluid can pass through the layers of product carried by these belts without entraining particles of product having a large size. Referring now to Figure 3, which schematically shows a cross section of the enclosure of an installation according to the invention.
Cette enceinte est à structure modulaire, comme on le verra par la suite, et est formée d'éléments assemblés bout à bout et ayant chacun la section transversale représentée en figure 3. Chaque élément modulaire comprend une partie inférieure formée par un caisson parallèlipipédique rectangle 40 qui porte les échangeurs de chaleur 14, les ventilateurs 18 et l'ossature de la partie supérieure 42 de l'élément modulaire, qui est constituée par une enveloppe sensiblement cylindrique à section elliptique recouvrant la face supérieure du caisson 40 et raccordée à celle-ci de façon étanche. L'ossature interne de cet élément modulaire est constituée de trois parois longitudinales verticales 44, 46 et 48 et de planchers horizontaux 50, 52 et 54. Les convoyeurs 12 représentés en figure 3 par des lignes en traits pointillés, sont supportés par cette ossature et s'étendent entre les parois verticales 44 et 46 en étant contenus à l'intérieur de l'enveloppe 42, c'est-à-dire entre le plancher intermédiaire 52 et le plancher supérieur 54. Un plancher oblique 56 est monté sur les parois verticales 44 et 46 de façon à partager l'espace entre les deux
convoyeurs 12. Les échangeurs de chaleur 14 sont portés par le plancher intermédiaire 52, entre les parois verticales 46 et 48 dont la partie supérieure porte des moyens 58 de levage d'une batterie d'échangeurs tels par exemple qu'un pont roulant. Les ventilateurs 18 sont disposés dans le caisson inférieur 40 et sont portés par la partie Inférieure de la paroi verticale 44. Chaque ventilateur 18 est entraîné par un moteur électrique 50 qui se trouve à l'extérieur de l'enceinte et est supporté par la partie inférieure de la paroi verticale 44. Un diffuseur transversal et horizontal 60 s'étend à l'intérieur du caisson inférieur 40, entre la roue de chaque ventilateur et la paroi verticale intermédiaire 46, et est raccordé à la face d'entrée des échangeurs 14 par des aubes de guidage fixes 62 logées dans le caisson inférieur 40, entre les parois verticales 46 et 48 de l'osssature.This enclosure is of modular structure, as will be seen below, and is formed of elements assembled end to end and each having the cross section shown in Figure 3. Each modular element comprises a lower part formed by a rectangular parallelepiped box 40 which carries the heat exchangers 14, the fans 18 and the framework of the upper part 42 of the modular element, which is constituted by a substantially cylindrical envelope with elliptical section covering the upper face of the box 40 and connected to the latter tightly. The internal framework of this modular element consists of three vertical longitudinal walls 44, 46 and 48 and horizontal floors 50, 52 and 54. The conveyors 12 represented in FIG. 3 by lines in dotted lines, are supported by this framework and extend between the vertical walls 44 and 46 being contained inside the envelope 42, that is to say between the intermediate floor 52 and the upper floor 54. An oblique floor 56 is mounted on the walls vertical 44 and 46 so as to share the space between the two conveyors 12. The heat exchangers 14 are carried by the intermediate floor 52, between the vertical walls 46 and 48, the upper part of which carries means 58 for lifting a battery of exchangers such as, for example, a traveling crane. The fans 18 are arranged in the lower box 40 and are carried by the lower part of the vertical wall 44. Each fan 18 is driven by an electric motor 50 which is located outside the enclosure and is supported by the part bottom of the vertical wall 44. A transverse and horizontal diffuser 60 extends inside the lower box 40, between the impeller of each fan and the intermediate vertical wall 46, and is connected to the inlet face of the exchangers 14 by fixed guide vanes 62 housed in the lower box 40, between the vertical walls 46 and 48 of the frame.
Les flèches de la figure 3 illustrent la circulation du fluide de séchage dans l'enceinte : le fluide de séchage sortant des diffuseurs 60 traverse les échangeurs de chaleur 14 et se partage en deux flux, dont l'un traverse le convoyeur supérieur 12 et dont l'autre, circulant sous le plancher oblique 56, traverse le convoyeur inférieur 12, ces deux flux se mélangeant l'un à l'autre en amont des ventilateurs 18 et des entrées des diffuseurs 60. En raison de ce mélange des flux sortant des deux convoyeurs, la température en amont des ventilateurs est sensiblement constante sur toute la longueur de l'enceinte. Les ventilateurs 18 disposés au même niveau dans le caisson inférieur 40, sont des ventilateurs axiaux, pour des raisons d'encombrement. Chaque élément modulaire comprend par exemple deux ventilateurs 18 délivrant chacun une pression statique relativement élevée, et entraînés chacun directement par un moteur électrique 59.The arrows in FIG. 3 illustrate the circulation of the drying fluid in the enclosure: the drying fluid leaving the diffusers 60 passes through the heat exchangers 14 and is divided into two flows, one of which crosses the upper conveyor 12 and of which the other, circulating under the oblique floor 56, crosses the lower conveyor 12, these two flows mixing one with the other upstream of the fans 18 and the inlets of the diffusers 60. Because of this mixture of the flows leaving the two conveyors, the temperature upstream of the fans is substantially constant over the entire length of the enclosure. The fans 18 arranged at the same level in the lower box 40 are axial fans, for reasons of space. Each modular element comprises for example two fans 18 each delivering a relatively high static pressure, and each driven directly by an electric motor 59.
Les diffuseurs 60 ont une longueur qui correspond sensiblement à la largeur des convoyeurs 12, et qui est par exemple de l'ordre de cinq mètres.The diffusers 60 have a length which corresponds substantially to the width of the conveyors 12, and which is for example of the order of five meters.
Le compresseur 24 de l'Installation alimente par un diffuseur à ailettes, une batterie de plusieurs faisceaux de tubes à ailettes qui sont superposés et raccordés en série et dans lesquels les tubes sont orientés transversalement par rapport à la direction longitudinale de l'enceinte et sont légèrement inclinés vers le bas, pour permettre l'évacuation des condensats. Les points les plus bas des boîtes collectrices des différents faisceaux de tubes à ailettes sont raccordés, pour l'évacuation des condensats, à l'entrée haute pression d'un ballon collecteur situé à l'extérieur de l'enceinte. La sortie de ce ballon collecteur peut être reliée à une vanne de détente, permettant de ramener la pression des condensats à la pression atmosphérique ambiante.
Le compresseur 24 alimenté par la séparateur 22 est par exemple un compresseur à deux étages, équipé en sortie de. diffuseurs à ailettes permettant une adaptation du débit de vapeur sans recyclage par la ligne antipompage du compresseur. La pression de refoulement du compresseur est ainsi sensiblement constante dans toute la gamme de variations du débit de vapeur.The compressor 24 of the Installation feeds by a finned diffuser, a battery of several bundles of finned tubes which are superimposed and connected in series and in which the tubes are oriented transversely to the longitudinal direction of the enclosure and are slightly inclined downwards, to allow the evacuation of condensates. The lowest points of the manifolds of the various bundles of finned tubes are connected, for the evacuation of condensates, to the high pressure inlet of a collecting flask situated outside the enclosure. The outlet of this collecting tank can be connected to an expansion valve, allowing the pressure of the condensates to be reduced to ambient atmospheric pressure. The compressor 24 supplied by the separator 22 is for example a two-stage compressor, fitted at the outlet of. finned diffusers allowing adaptation of the steam flow rate without recycling by the anti-pumping line of the compressor. The discharge pressure of the compressor is thus substantially constant throughout the range of variations in the steam flow rate.
On se réfère maintenant à la figure 4 pour décrire un exemple de réalisation pratique d'un élément modulaire de l'installation selon l'inven¬ tion. Le caisson 40, formant la partie inférieure de l'enceinte et portant les ventilateurs et les échangeurs de chaleur, est constitué de tôles planes munies de raidisseurs, et est rigidifié par un grand nombre de traverses, longerons et croisillons. La partie supérieure 42 de l'enceinte est constituée de tôles planes munies de raidisseurs longitudinaux et soudées sur des profilés transversaux qui sont cintrés en arceaux dans le sens de leur plus grande inertie. L'assemblage de deux éléments modulaires consécutifs se fait par rapprochement et boulonnage des profilés transversaux d'extrémité de ces deux éléments. Les tôles sont ensuite soudées bord à bord à l'intérieur, par des soudures continues, chaque tôle ayant été préalablement fixée par une soudure discontinue sur le profilé transversal cintré correspon¬ dant.Reference is now made to FIG. 4 to describe a practical embodiment of a modular element of the installation according to the invention. The box 40, forming the lower part of the enclosure and carrying the fans and the heat exchangers, consists of flat sheets provided with stiffeners, and is stiffened by a large number of crosspieces, side members and cross-pieces. The upper part 42 of the enclosure is made up of flat sheets provided with longitudinal stiffeners and welded to transverse profiles which are curved in arches in the direction of their greatest inertia. The assembly of two consecutive modular elements is done by bringing together and bolting the transverse end profiles of these two elements. The sheets are then welded edge to edge on the inside, by continuous welds, each sheet having been previously fixed by a discontinuous weld on the transverse bent profile corresponding.
Une installation selon l'invention peut être constituée de six éléments modulaires assemblés bout à bout, pour avoir une longueur totale d'environ trente mètres, une largeur de douze mètres et une hauteur de douze mètres. L'ensemble de l'installation repose sur une structure fixe de support, par l'intermédiaire de patins de glissement qui permettent un déplacement longitudinal et transversal des parties d'extrémité du caisson inférieur 40, par rapport au centre de ce caisson qui reste fixe. Ce montage permet d'absorber les dilatations thermiques différentielles de l'enceinte, qui peu- vent être relativement importantes.An installation according to the invention can consist of six modular elements assembled end to end, to have a total length of about thirty meters, a width of twelve meters and a height of twelve meters. The entire installation rests on a fixed support structure, by means of sliding pads which allow a longitudinal and transverse movement of the end parts of the lower box 40, relative to the center of this box which remains fixed. . This arrangement makes it possible to absorb the differential thermal expansions of the enclosure, which can be relatively large.
Lorsque l'installation est conçue pour permettre l'évaporation d'une quantité d'eau de l'ordre de 20 tonnes par heure, le débit Q de vapeur d'eau est compris entre 700 et 1 500 tonnes/heure selon la pression de refoulement de compresseur choisie. Le débit q de vapeur prélevé pour alimenter le compresseur 24 est de l'ordre de 20 tonnes par heure et est fourni par le compresseur 24 aux échangeurs de chaleur 14 à une température de l'ordre de 150 ° C et une
pression de l'ordre de 4 à 5 bars. L'enceinte est alimentée par un débit d'environ 28 tonnes par heure de pulpe de betterave humide à une tempéra¬ ture de 50 °C, qui sort de l'enceinte avec une teneur en matière sèche de l'ordre de 90 %. La consommation d'énergie est d'environ 180 kWh par tonne d'eau évaporée.When the installation is designed to allow the evaporation of a quantity of water of the order of 20 tonnes per hour, the flow rate Q of water vapor is between 700 and 1,500 tonnes / hour depending on the pressure of compressor discharge chosen. The flow rate q of steam withdrawn to supply the compressor 24 is of the order of 20 tonnes per hour and is supplied by the compressor 24 to the heat exchangers 14 at a temperature of the order of 150 ° C. and a pressure of the order of 4 to 5 bars. The enclosure is supplied with a flow rate of approximately 28 tonnes per hour of wet beet pulp at a temperature of 50 ° C., which leaves the enclosure with a dry matter content of the order of 90%. Energy consumption is around 180 kWh per tonne of water evaporated.
La pression dans l'installation de séchage reste très proche de la pression atmosphérique. Ceci est obtenu au moyen d'un évent permanent mettant en communication une partie de l'installation (par exemple la zone située sous les convoyeurs) avec l'extérieur. L'excédent thermique global du système séchoir + compresseur conduit à une légère fuite de vapeur empêchant les rentrées d'air par cet évent permanent.The pressure in the drying installation remains very close to atmospheric pressure. This is achieved by means of a permanent vent connecting part of the installation (for example the area under the conveyors) with the outside. The overall thermal surplus of the dryer + compressor system leads to a slight vapor leak preventing air from entering through this permanent vent.
Les dispositions décrites dans l'invention s'appliquent également à un séchoir à vapeur d'eau, mais sans recompression mécanique de vapeur, ainsi qu'à un séchoir utilisant de l'air comme fluide de séchage, avec recirculation partielle de ce fluide de séchage.
The arrangements described in the invention also apply to a steam dryer, but without mechanical vapor recompression, as well as to a dryer using air as drying fluid, with partial recirculation of this fluid. drying.
Claims
REVENDICATIONS
1) Installation industrielle de séchage d'un produit humide, du type à recirculation au moins partielle d'un fluide de séchage, comprenant une enceinte (10) à structure modulaire équipée de convoyeurs (12) à tapis de déplacement du produit, des ventilateurs (18) de circulation d'un débit (Q) de fluide de séchage dans l'enceinte, des moyens (20) de prélèvement d'une fraction (q) de ce débit, et des échangeurs de chaleur (14) traversés par le débit (Q) de fluide de séchage, caractérisée en ce que ladite enceinte comporte une partie inférieure formée par un caisson (40) rigidifié à section transversale rectangulaire, supportant les ventilateurs (18), les échangeurs de chaleur (14) et l'ossature d'une partie supérieure (42) ayant la forme d'une portion de cylindre qui recouvre la face supérieure du caisson (40) et est raccordée à celle-ci, et qui entoure les convoyeurs (12) et les échangeurs de chaleur (14).1) Industrial installation for drying a wet product, of the type with at least partial recirculation of a drying fluid, comprising an enclosure (10) with a modular structure equipped with conveyors (12) with product movement conveyor, fans (18) for circulating a flow (Q) of drying fluid in the enclosure, means (20) for withdrawing a fraction (q) of this flow, and heat exchangers (14) through which the drying fluid flow (Q), characterized in that said enclosure has a lower part formed by a rigidified box (40) with rectangular cross section, supporting the fans (18), the heat exchangers (14) and the framework an upper part (42) in the form of a cylinder portion which covers the upper face of the box (40) and is connected to it, and which surrounds the conveyors (12) and the heat exchangers (14 ).
2) Installation selon la revendication 1, caractérisée en ce que la partie supérieure (42) de l'enceinte comprend deux convoyeurs (21) verticalement superposés et des moyens (36) de transfert du produit d'une extrémité du convoyeur supérieur à l'extrémité correspondante du convoyeur inférieur, une paroi de séparation (56) étant prévue entre les convoyeurs sur toute leur longueur pour délimiter dans l'enceinte une zone supérieure de séchage comprenant le convoyeur supérieur (12) et traversée par un premier flux de fluide de séchage, une zone inférieure de séchage comprenant le convoyeur inférieur et traversée par un second flux de fluide de séchage, et une zone de mélange de ces deux flux sortant des zones de séchage, qui est raccordée au caisson inférieur (40) en amont des ventilateurs (18). 3) Installation selon la revendication 1 ou 2, caractérisée en ce que les ventilateurs (18) sont des ventilateurs axiaux qui sont orientés transversale¬ ment et supportés à un même niveau par le caisson inférieur (40) et qui sont raccordés aux faces d'entrée des échangeurs de chaleur (14) par des diffuseurs transversaux (60) logés dans le caisson inférieur (40) et s'étendant sur toute la largeur des convoyeurs (12).2) Installation according to claim 1, characterized in that the upper part (42) of the enclosure comprises two conveyors (21) vertically superimposed and means (36) for transferring the product from one end of the upper conveyor to the corresponding end of the lower conveyor, a partition wall (56) being provided between the conveyors over their entire length to delimit in the enclosure an upper drying zone comprising the upper conveyor (12) and crossed by a first flow of drying fluid , a lower drying zone comprising the lower conveyor and traversed by a second flow of drying fluid, and a zone for mixing these two flows leaving the drying zones, which is connected to the lower box (40) upstream of the fans ( 18). 3) Installation according to claim 1 or 2, characterized in that the fans (18) are axial fans which are oriented transversely and supported at the same level by the lower box (40) and which are connected to the faces of inlet of the heat exchangers (14) by transverse diffusers (60) housed in the lower box (40) and extending over the entire width of the conveyors (12).
4) Installation selon l'une des revendications 1 à 3, caractérisée en ce que la partie inférieure du caisson (40) repose sur une structure de support fixe par l'intermédiaire de patins de glissement autorisant un déplacement
longitudinal et transversal .des parties d'extrémité du caisson (40) par rapport à son centre fixe, sous l'effet des dilatations thermiques différen¬ tielles de l'enceinte.4) Installation according to one of claims 1 to 3, characterized in that the lower part of the box (40) rests on a fixed support structure by means of sliding pads allowing movement longitudinal and transverse. of the end parts of the box (40) relative to its fixed center, under the effect of differential thermal expansions of the enclosure.
5) Installation selon l'une des revendications précédentes, caractérisée en ce que les échangeurs de chaleur (14) sont constitués par une batterie de plusieurs faisceaux de tubes à ailettes traversés par le fluide de séchage.5) Installation according to one of the preceding claims, characterized in that the heat exchangers (14) consist of a battery of several bundles of finned tubes traversed by the drying fluid.
6) Installation selon l'une des revendications précédentes, caractérisée en ce que le fluide de séchage étant de la vapeur d'eau, les moyens (20) de prélèvement de la fraction (q) du débit de vapeur d'eau sont reliés à l'entrée d'un compresseur (24) alimentant les échangeurs de chaleur (14).6) Installation according to one of the preceding claims, characterized in that the drying fluid being water vapor, the means (20) for sampling the fraction (q) of the water vapor flow rate are connected to the inlet of a compressor (24) supplying the heat exchangers (14).
7) Installation selon la revendication 6, caractérisée en ce que le compresseur (24) alimentant les échangeurs de chaleur (14) est raccordé aux échangeurs par des diffuseurs à ailettes.7) Installation according to claim 6, characterized in that the compressor (24) supplying the heat exchangers (14) is connected to the exchangers by finned diffusers.
8) Installation selon la revendication 6 ou 7, caractérisée en ce que le compresseur (24) est alimenté en vapeur d'eau par un séparateur (22), permettant la séparation et l'extraction des particules de produits entraî¬ nées par ladite fraction prélevée (q) du débit de vapeur d'eau.8) Installation according to claim 6 or 7, characterized in that the compressor (24) is supplied with steam by a separator (22), allowing the separation and the extraction of the particles of products entrained by said fraction taken (q) from the water vapor flow.
9) Installation selon l'une des revendications précédentes, caractérisée en ce que les moyens (20) de prélèvement de ladite fraction (q) du débit de fluide de séchage sont prévus dans la partie du caisson (40) située sous les échangeurs de chaleur (14).9) Installation according to one of the preceding claims, characterized in that the means (20) for removing said fraction (q) of the drying fluid flow are provided in the part of the box (40) located under the heat exchangers (14).
10) Installation selon l'une des revendications précédentes, caractérisée en ce que les échangeurs de chaleur (14) étant formés de faisceaux verticalement superposés de tubes à ailettes, la partie supérieure de l'enceinte comprend, au-dessus des échangeurs, des moyens (58) de levage des faisceaux supérieurs de tubes à ailettes, pour faciliter le nettoyage des échangeurs pendant les périodes d'arrêt de l'installation.10) Installation according to one of the preceding claims, characterized in that the heat exchangers (14) being formed of vertically superimposed bundles of finned tubes, the upper part of the enclosure comprises, above the exchangers, means (58) for lifting the upper bundles of finned tubes, to facilitate cleaning of the exchangers during periods of plant shutdown.
11) Installation selon l'une des revendications précédentes, caractérisée en ce que l'enceinte est constituée d'éléments modulaires assemblés longitu- dinalement bout à bout, comprenant chacun un caisson inférieur (40) et une partie supérieure (42) sensiblement en portion de cylindre, cette dernière étant formée par des tôles à raidisseurs longitudinaux et par des profilés transversaux cintrés en arceaux sur lesquels sont soudées les tôles, ces éléments modulaires étant fixés les uns aux autres par leurs profilés cintrés d'extrémité.11) Installation according to one of the preceding claims, characterized in that the enclosure consists of modular elements assembled longitudinally end to end, each comprising a lower box (40) and an upper part (42) substantially in portion of cylinder, the latter being formed by sheets with longitudinal stiffeners and by transverse profiles bent into arches on which the sheets are welded, these modular elements being fixed to each other by their bent end profiles.
12) Installation selon l'une des revendications précédentes, caractérisée en ce qu'elle comprend un évent permanent mettant en communication
l'intérieur de l'installation avec l'extérieur, pour maintenir la pression dans l'installation à une valeur voisine de la pression atmosphérique.
12) Installation according to one of the preceding claims, characterized in that it comprises a permanent vent putting in communication the interior of the installation with the exterior, to maintain the pressure in the installation at a value close to atmospheric pressure.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8616181A FR2607230B1 (en) | 1986-11-20 | 1986-11-20 | INDUSTRIAL PLANT FOR DRYING A WET PRODUCT, AT LEAST PARTIALLY RECIRCULATING TYPE OF A DRYING FLUID |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1989005949A1 true WO1989005949A1 (en) | 1989-06-29 |
Family
ID=9341029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/FR1987/000514 WO1989005949A1 (en) | 1986-11-20 | 1987-12-23 | Industrial installation for drying a moist product with at least partial recirculation of a drying fluid |
Country Status (2)
| Country | Link |
|---|---|
| FR (1) | FR2607230B1 (en) |
| WO (1) | WO1989005949A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0413519A2 (en) * | 1989-08-17 | 1991-02-20 | W.R. Grace & Co.-Conn. | Zoned cylindrical dryer |
| DE4022702C1 (en) * | 1990-07-17 | 1991-11-28 | Fritz Egger Ges.M.B.H., Sankt Johann In Tirol, At | |
| EP0570970A1 (en) * | 1992-05-22 | 1993-11-24 | FRITZ EGGER GESELLSCHAFT m.b.H. | Dryer for bulk or pourable materials |
| NO20050189A (en) * | 2005-01-13 | 2006-02-20 | Hammer Asbjoern | Device for drying material |
| US10006714B2 (en) | 2007-08-07 | 2018-06-26 | Mars, Incorporated | Apparatus for drying a material |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2607230B1 (en) * | 1986-11-20 | 1990-12-07 | Bertin & Cie | INDUSTRIAL PLANT FOR DRYING A WET PRODUCT, AT LEAST PARTIALLY RECIRCULATING TYPE OF A DRYING FLUID |
| FR2658904B1 (en) * | 1990-02-23 | 1992-07-10 | Bertin & Cie | DRYER FOR DIVIDED PRODUCTS. |
| GB0414381D0 (en) * | 2004-06-28 | 2004-07-28 | Bch Ltd | A drying/cooling conveyor |
| DE102007037607A1 (en) | 2007-08-07 | 2009-02-12 | Mars Incorporated | Method and apparatus for drying an extruded material |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE124809C (en) * | 1900-06-19 | 1901-11-12 | ||
| US1779622A (en) * | 1926-08-30 | 1930-10-28 | Henry A Dreffein | Oven |
| US2198362A (en) * | 1939-02-04 | 1940-04-23 | Nat Standard Co | Metal sheet drying oven |
| CH338399A (en) * | 1956-03-03 | 1959-05-15 | Buehler Ag Geb | Dryers, in particular for pasta |
| GB1034728A (en) * | 1963-11-16 | 1966-07-06 | Louise Chomat | Improvements in and relating to tunnel furnaces |
| US4140893A (en) * | 1977-05-06 | 1979-02-20 | Don Renteria | Ball warming apparatus and methods of constructing and utilizing same |
| FR2524129A1 (en) * | 1982-03-26 | 1983-09-30 | Bertin & Cie | Moisture extn. by contacting with superheated steam in closed circuit - the superheater recuperating latent heat from mechanically compressed satd. steam |
| FR2607230A1 (en) * | 1986-11-20 | 1988-05-27 | Bertin & Cie | INDUSTRIAL PLANT FOR DRYING A WET PRODUCT, AT LEAST PARTIALLY RECIRCULATING TYPE OF A DRYING FLUID |
-
1986
- 1986-11-20 FR FR8616181A patent/FR2607230B1/en not_active Expired - Lifetime
-
1987
- 1987-12-23 WO PCT/FR1987/000514 patent/WO1989005949A1/en unknown
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE124809C (en) * | 1900-06-19 | 1901-11-12 | ||
| US1779622A (en) * | 1926-08-30 | 1930-10-28 | Henry A Dreffein | Oven |
| US2198362A (en) * | 1939-02-04 | 1940-04-23 | Nat Standard Co | Metal sheet drying oven |
| CH338399A (en) * | 1956-03-03 | 1959-05-15 | Buehler Ag Geb | Dryers, in particular for pasta |
| GB1034728A (en) * | 1963-11-16 | 1966-07-06 | Louise Chomat | Improvements in and relating to tunnel furnaces |
| US4140893A (en) * | 1977-05-06 | 1979-02-20 | Don Renteria | Ball warming apparatus and methods of constructing and utilizing same |
| FR2524129A1 (en) * | 1982-03-26 | 1983-09-30 | Bertin & Cie | Moisture extn. by contacting with superheated steam in closed circuit - the superheater recuperating latent heat from mechanically compressed satd. steam |
| FR2607230A1 (en) * | 1986-11-20 | 1988-05-27 | Bertin & Cie | INDUSTRIAL PLANT FOR DRYING A WET PRODUCT, AT LEAST PARTIALLY RECIRCULATING TYPE OF A DRYING FLUID |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0413519A2 (en) * | 1989-08-17 | 1991-02-20 | W.R. Grace & Co.-Conn. | Zoned cylindrical dryer |
| EP0413519A3 (en) * | 1989-08-17 | 1992-05-20 | W.R. Grace & Co.-Conn. | Zoned cylindrical dryer |
| DE4022702C1 (en) * | 1990-07-17 | 1991-11-28 | Fritz Egger Ges.M.B.H., Sankt Johann In Tirol, At | |
| EP0570970A1 (en) * | 1992-05-22 | 1993-11-24 | FRITZ EGGER GESELLSCHAFT m.b.H. | Dryer for bulk or pourable materials |
| NO20050189A (en) * | 2005-01-13 | 2006-02-20 | Hammer Asbjoern | Device for drying material |
| US10006714B2 (en) | 2007-08-07 | 2018-06-26 | Mars, Incorporated | Apparatus for drying a material |
| US10113794B2 (en) | 2007-08-07 | 2018-10-30 | Mars, Incorporated | Method for drying a material |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2607230B1 (en) | 1990-12-07 |
| FR2607230A1 (en) | 1988-05-27 |
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