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
  • F26B17/12—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed solely by gravity, i.e. the material moving through a substantially vertical drying enclosure, e.g. shaft
  • F26B17/14—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed solely by gravity, i.e. the material moving through a substantially vertical drying enclosure, e.g. shaft the materials moving through a counter-current of gas
  • F26B17/1408—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed solely by gravity, i.e. the material moving through a substantially vertical drying enclosure, e.g. shaft the materials moving through a counter-current of gas the gas being supplied and optionally extracted through ducts extending into the moving stack of material
  • F26B17/1416—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed solely by gravity, i.e. the material moving through a substantially vertical drying enclosure, e.g. shaft the materials moving through a counter-current of gas the gas being supplied and optionally extracted through ducts extending into the moving stack of material the ducts being half open or perforated and arranged horizontally

Definitions

• the invention relates to shaft dryers for bulk materials, such as cereals.
• the bulk material sinks downwards in the shaft at a speed which is set by the amount of bulk material which is continuously discharged at the lower end of the shaft.
• the bulk material passes between a plurality of approximately horizontal and mostly parallel to each other in horizontal planes arranged so-called air roofs, through which bridge the shaft from one to the other side wall and like a roof have an open bottom.
• the bulk material is thereby divided into individual, adjacent to each other good flows.
• each roof is open, so that air can enter the roof via this open side and thus be blown into the shaft or sucked in, which is dry, usually heated air.
• These roofs are called Zu Kunststoffdumbleer.
• the other, the so-called exhaust air roofs are connected with their open end with an exhaust duct of the so-called exhaust hood, so that from them by the dry matter enriched with moisture and usually cooled exhaust air can escape.
• the air thus absorbs on its way from a Zu Kunststoffdach to an exhaust air duct across the dry material of this moisture.
• drying duct itself i. whose outer shell with the supporting frame and the internals such as the air roofs, consists of several superimposed modules, usually made of sheet steel, stainless steel or aluminum, which are stacked and therefore can be installed quickly, since the air roofs in the modules there before finished installed.
• the air roofs are arranged directly below one another in the vertical direction, ie not offset from one another in the individual planes, so that one plane contains only roofs and the next level only exhaust air roofs.
• the disadvantage of this design is that the bulk material jams on the individual roofs, but runs relatively quickly down between them, and the jammed goods either overheated or not or dried only when the emptying of the shaft, so that results in a non-uniform drying.
• the air roofs are not directly with each other, but laterally offset from each other, so that a roof is located respectively below the gap between the roofs of the overlying level, d. H. in a rhombus grid with exclusively oblique grid lines.
• a third known design - as shown in Figure 1 c - avoids this disadvantage by the individual modules, which are identically constructed, each viewed in plan view rotated by 180 ° to each other mounted stacked. If an even number of levels is present within the modules, this means that although the flow direction of a partial flow of the bulk material remains the same within a module, on the change from one module to the next but also the direction of flow of the partial flow from one to the other Page changes.
• the shaft dryer is achieved by the arrangement of the air roofs - as described in claim 1, that in addition to the alternating flow of the good flows from the left and right at the transition between the modules see the deviation of the flow rate of the drying air from the mean by accumulation of a kind of air roofs in the border area between two modules is avoided.
• the modules have an even number of levels with air roofs on top of each other and in particular all modules have the same number of levels, on the one hand, the cost of manufacturing and possibly also the stock is reduced and yet when you put the modules to a shaft dryer, the accumulation of a kind roofs in the border area between two modules avoided, if the modules are each set without twisting by 180 ° in the same orientation on top of each other.
• the offset by one half of the air roof distance from plane to plane ensures that air roofs of the same kind are vertically arranged vertically one above the other.
• this offset can also be a lesser additional offset and repeat itself several times over the height of the dryer, but then preferably always in the same direction, so that the sum of the additional offset distances over the Height of the dryer is equal to or approximately equal to the width of a complete material flow.
• this additional offset is achieved by having within a module all roofs this additional offset from the roofs of the preceding, overlying module, so that within a module as before the air roofs of the same kind again lie exactly vertically one above the other.
• a uniform passage and thus a uniform drying can be improved by the shaft dryer by the discharge slide is convex toward the interior of the dryer or on the flat applicator a so-shaped, so arched or angled, bent up, cover plate is.
• the heat output of the outer walls of the shaft dryer can be minimized to the environment, either alone by two-shell construction of the outer skin, so double-layer planking, o- by insulating the outer lining z. B. by mineral wool or by a combination of both measures, in which case the insulating material is preferably located in the space between the two Beplankungs füren z. B. consist of metal sheets.
• a heat recovery can be carried out in which the moist air enriched by the bulk drying air withdrawn before discharge to the environment at least part of their heat and directly or indirectly the new sucked and to be used for drying ambient air is supplied, for. B. via heat exchangers, in particular glass tube heat exchanger.
• the energy saving serves the arrangement of so-called Schwitzzonen in the process, especially in the lower area of the dryer shaft:
• This cycle time is used to equalize the different degrees heated grains and their still different moisture content, especially from the grain inside to the grain outside, due to the residence time and the mutual contact of the grains and the resulting heat transfer.
• the even higher moisture content in the core region of the grain is thereby equalized, so that the moisture still present in the interior migrates to the outside and to the surface of the grain, u. a. due to the existing, still relatively high temperature in the grains, for example, 60 ° to 70 ° due.
• the drying method on which the invention is based is based on the fact that the individual crop flows are alternately supplied with drying air alternately from the top to the bottom once from the left and once from the right, but in addition the drying air supplied from the incoming roofs of one level is always removed via the air-cooled roofs is located in the immediately above or below level, so there is no accumulation of roofs or exhaust air at two successive levels.
• the whole rice kernel (the so-called raw paddy), which is still complete after harvesting, consists of the flour meal, which is usually sold for sale, which is surrounded by a so-called brown silver skin, which in turn is enveloped by the shell proper, the so-called spelled.
• brown rice After removal of the spelled, the so-called brown rice is formed, in which the silver skin is present. This is usually removed when polishing the brown rice, making it white and ready for sale.
• Example be at least partially avoided by the parboiled method in which the paddy, which usually comes with a moisture content of 22% by weight from the field, soaked in water and cooked, in particular with the addition of steam or only with the aid of steam , becomes.
• the ingredients are mainly released from the silver skin and diffuse at least partially into the flour grain, the subsequent cooking time is shortened and reduces the proportion of broken grains.
• the temperatures of the drying air drop, so that at about 20% residual moisture in the drying material with 50 ° to 60 ° Celsius is used in the drying air.
• a reject due to excessive drying of individual grains of about 3% is therefore currently considered a good result.
• Another method of processing paddy is steaming, in which the paddy is precooked without steam soaking, especially steaming.
• this steamed paddy - which in turn should improve especially the cooking properties - must then be dried down quickly and before peeling in 1 to 3 drying stages, in particular as described by the parboiled method.
• the efficiency can be further increased by not only in the annealing cells in between a leveling of temperature and humidity is carried out, but in addition, at the end of the annealing an application of drying air at ambient temperature and without additional heating of this cooling air is carried out in a flow cooler.
• this dissipates the moisture diffused from the interior of the grains on the surface thereof with little expenditure of energy, in which the surroundings in the throughflow cooler only through the material to be dried, but does not have to be heated.
• the material to be dried is also cooled, with the result that in the subsequent drying stage, the drying air must be heated to a lower temperature, since the temperature of the drying air must always be a sufficient amount above the temperature of the material itself.
• Fig. 3 an air roof in detail
• Fig. 4 the discharge of the dryer shaft.
• Figures 1 a and b show a known basic structure of a shaft dryer from the two offset by 90 ° side views:
• FIG. 1 a The mode of operation of a shaft dryer can be seen with reference to FIG. 1 a:
• the dryer shaft 1 in which the drying material, such as cereals, is located, where it slowly migrates from top to bottom and thereby dried, the throughput rate of the per unit time removed amount at the discharge unit 20th at the lower end of the dryer shaft 1 depends.
• the drying material is dried in the dryer shaft 1 by means of drying air flowing through it, which is heated by a hot air generator 18 and a Zu Kunststoffverteilmodul 16, which as a drying air 15 leading housing on the outside of the dryer shaft 1 via z. B. is grown substantially the entire height is passed into the dryer shaft 1. From there, it flows on the opposite side and after passing through the material to be dried via a exhaust fan module 17, which is again housed in a housing-like manner on the dryer shaft 1, is collected there and discharged completely or partially to the environment via an exhaust fan 19.
• the still mostly warm air can be withdrawn energy by a heat exchanger, not shown, or the exhaust air is partially mixed in a cycle again the supply air, possibly after renewed heating.
• the drying air 15 enters the drying shaft 1 via air guide elements, for example, so-called Zu Kunststoffdumbleer 2, of which in Fig. 1 a is shown by way of example.
• air guide elements for example, so-called Zu Kunststoffdumbleer 2, of which in Fig. 1 a is shown by way of example.
• These are roof-like, downwardly open sheet metal elements which attach to the supply air side at corresponding connection openings in the front wall 21 of the drying shaft 1 to the supply air module 16 and are open and are supplied from there with supply air 15, and closed at the opposite end are, for. B.
• Zutions- and exhaust air roofs 2, 3 are a plurality of superimposed and juxtaposed, as explained in more detail with reference to FIGS 2.
• the entire tower-like structure of the shaft dryer which is usually a steel construction, assembled from superimposed modules 1 a, b, wherein already within one of the modules 1 a, b, several levels of air roofs 2, 3 are arranged one above the other.
• Fig. 1 a the shaft dryer 1 is shown from the side of the hot air generator 18, from which it is apparent that supply air module 16 and exhaust module 17 are here only on one of the four sides of the generally rectangular dryer shaft 1.
• the Zu poverty- and exhaust air roofs from the supply-side front wall 21 to the exhaust-side rear wall 22 of the shaft dryer 1 through, and are attached to these frontally.
• the front-side closure on one side of the air roofs is generated by the fact that there is no through-opening 23 for the drying air 15 in the corresponding wall-front wall 21 or rear wall 22 -but only the hole pattern 24 also shown in FIG. through which be screwed through the end faces of the air roofs with the corresponding wall 21, 22 of the dryer shaft 1.
• Each module 1 a, b, ... of the dryer shaft 1 thus consists of four arranged in a square, bolted together plates, namely front wall 21, rear wall 22, each equipped with passages 23 and hole patterns, and mounted therebetween, continuously closed side walls.
• the dryer shaft 1 is generated by superimposed modules 1 a, b, ..., which are as far as possible - at least in terms of items - to be identical in order to minimize the production cost.
• the air roofs 2, 3 are arranged one above the other within the dryer shaft 1 and also within the individual modules 1 a, b,... In horizontal planes 4 a, b,.
• FIG. 2b shows such a front wall 21 in the unwinding, that is to say including the marginal folds 25, 26 for screwing to the continuously closed side walls.
• the plurality of superimposed front walls 21 show the arrangement of the passage openings 23, behind each of which a Zuluftdach 2 is attached to the arrangement of the hole pattern 24, behind each of which an exhaust roof 3 is attached, and thus the arrangement of Zuluftdumbleer 2 to the exhaust air roofs 3, which can also be seen in perspective view in FIG. 2a:
• the air roofs of a plane z. B. 4a are due to the opposite equal inclination of the diagonal lines 5, 6 so that just above or below the next but one or more horizontally located below z. B. 4c of roofs.
• each module 1 a, b includes an even number of levels 4a, b,... Of roofs, in this case four levels, the individual modules 1 a, b and thus their front walls 21 and rear walls 22 can be used for this normal case be formed identical.
• each of the product streams 7, which are generated by the separating action of the air roofs 2, 3, to pass alternately once from their top side downwards through the dryer shaft 1 the left side and once from the right side of a respective Zu Kunststoffdach 2 from with drying air 15 is applied and that nevertheless at no point the Gutstromes 7 a disproportionate accumulation of Zu Kunststoffdumbleern 2 or exhaust roofs 3 occurs, the immediate adverse local effects such as increasing the Tem - Result of drying material or increased pressure drop has the consequence.
• an additional transverse offset 9 is effected by a fraction of the width 8 of the crop stream 7, that is, where the diagonal lines 5, 6 have a lateral offset.
• the advantage is that only two types of front walls 21 and 21 'are required over the height of the shaft dryer 1, and accordingly only two types of rear walls 22, 22' themselves if such a power split is performed several times in succession over the height of the shaft dryer 1.
• the air roofs which are designed to be identical in the rule as incoming roof 2 and exhaust roof 3, a decreasing from the open end to the closed end side cross-section, according to z. B. in exhaust air roofs to the open front side increasing air supply.
• FIG. 3 shows such an air roof 2, 3 in detail, in Fig. 3a in the settlement with the two later end-side bevels 25, 26 for attachment to the front walls 21 and rear walls 22 of the drying shaft.
• the height of the roof 2, 3 decreases continuously toward one end face, that is to say the roof ridge represents a straight, inclined line in the side view, and the lower opening width also preferably decreases somewhat in this direction.
• the tapered roof can be made by simple, straight bends from a flat sheet metal blank, as seen in the development of Fig. 3a.
• the so finished and folded air roofs can be stacked in a simple manner in relatively large numbers one above the other and thus transport a large number of air roofs with minimal transport volume. This is important in view of the fact that such an air roof 2, 3 is several meters long and already in an average shaft dryer 1 quite about 200 air roofs or more are needed.
• FIG. 4 A further constructional detail is shown in the discharge unit 20 shown in FIG. 4, which is shown in FIG. 4 in the side view - from which a detail is shown in FIG. 4c and in the plan view in FIG. 4b:
• each line-shaped grooves connect with V-shaped cross-section, in the bottom turn strip-shaped outlet openings 30 are from which the dried material can be drained.
• the outlet openings 30 can be completely closed by likewise strip-shaped discharge slides 12 which, for reasons of stability in the side view, in their turn are V-shaped, but are covered by an overlying, slightly convex top plate 13 are on which in the closed state of the outlet openings 30 presses the Trocknungsgut.
• All discharge slide 12 including their cover plates 13 are connected at their front ends in the opening direction of the Austragsschieber 12 - in the side view of Fig. 4a to the left or right - extending longitudinal struts to a Austragsrahmen 29, of an actuating cylinder 27 in Figures 4 to the left or can be moved to the right and thus the outlet openings 30 closes or partially opens.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Drying Of Solid Materials (AREA)
• Buildings Adapted To Withstand Abnormal External Influences (AREA)
• Building Environments (AREA)

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Publications (2)

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• 2007
  • 2007-06-22 DE DE102007028781A patent/DE102007028781A1/de not_active Withdrawn
• 2008
  • 2008-06-23 RU RU2008138139/06A patent/RU2445562C2/ru active
  • 2008-06-23 DE DE502008002311T patent/DE502008002311D1/de active Active
  • 2008-06-23 UA UAA200813755A patent/UA92524C2/ru unknown
  • 2008-06-23 EP EP08774228A patent/EP2160558B1/fr active Active
  • 2008-06-23 AT AT08774228T patent/ATE495418T1/de active
  • 2008-06-23 CA CA002656105A patent/CA2656105A1/fr not_active Abandoned
  • 2008-06-23 CN CN2008800005281A patent/CN101631997B/zh active Active
  • 2008-06-23 US US12/377,890 patent/US8572863B2/en active Active
  • 2008-06-23 BR BRPI0804521-6A patent/BRPI0804521B1/pt active IP Right Grant
  • 2008-06-23 WO PCT/EP2008/057965 patent/WO2009000812A2/fr active Application Filing
  • 2008-06-23 PL PL08774228T patent/PL2160558T3/pl unknown

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