Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B3/00—Drying solid materials or objects by processes involving the application of heat
  • F26B3/02—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air
  • F26B3/06—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour flowing through the materials or objects to be dried
  • F26B3/08—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour flowing through the materials or objects to be dried so as to loosen them, e.g. to form a fluidised bed
  • F26B3/092—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour flowing through the materials or objects to be dried so as to loosen them, e.g. to form a fluidised bed agitating the fluidised bed, e.g. by vibrating or pulsating
  • F26B3/0923—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour flowing through the materials or objects to be dried so as to loosen them, e.g. to form a fluidised bed agitating the fluidised bed, e.g. by vibrating or pulsating by mechanical means, e.g. vibrated plate, stirrer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B1/00—Preliminary treatment of solid materials or objects to facilitate drying, e.g. mixing or backmixing the materials to be dried with predominantly dry solids
  • F26B1/005—Preliminary treatment of solid materials or objects to facilitate drying, e.g. mixing or backmixing the materials to be dried with predominantly dry solids by means of disintegrating, e.g. crushing, shredding, milling the materials to be dried
• • 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
  • F26B17/10—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by fluid currents, e.g. issuing from a nozzle, e.g. pneumatic, flash, vortex or entrainment dryers

Definitions

• the invention relates to a process for continuous dis ⁇ integration and/or drying of materials, such as paste, sludge, press cake, filter cake or the like, particular ⁇ ly fibrous materials in an apparatus comprising a pro- cessing chamber having a chamber wall, the main shape thereof being substantially like a surface of revolu ⁇ tion, and having an essentially vertical axis and a sub ⁇ jacent blast box, and said process including a continu ⁇ ous : - feeding of a disintegration and drying gas from the blast box to the processing chamber,
• DK 149.583B thus discloses an apparatus for fluidization drying and disintegration of a paste—like material, whe ⁇ rein the apparatus comprises a cylindrical drying cham ⁇ ber provided with an upwardly tapering bottom, and wherein the fluidization and drying medium is fed to the chamber through a circumferential slit between the tape ⁇ ring bottom and the chamber wall from an annular distri ⁇ bution chamber surrounding the lower part of the drying chamber.
• An agitator coaxially arranged in the drying chamber and having blades being parallel to the tapering bottom ensures that no partially dried particles accumu ⁇ late on the tapering bottom and that an agitation and disintegration of the largest particles from the paste ⁇ like material take place.
• US—A—4, 623 , 098 discloses a machine for batchwise granu ⁇ lation, coating, mixing and drying of powdery or granu ⁇ lar raw materials, in which a rotatable horizontal disc is arranged at the bottom of a casing coaxially therein, said disc leaving an annular slit at the casing wall, through which the drying gas is injected from a sub ⁇ jacent dispersing chamber. Furthermore, drying gas may be injected from another dispersing chamber through per ⁇ forations in the rotary disc.
• An agitator is arranged above the rotary disc and coaxially therewith, above which a locally functioning, fast rotating disintegrator is arranged near the chamber wall.
• the axial speed of gas flow in the drying chamber is so moderate that the material remains at the bottom of the chamber.
• Processed material is discharged through an discharge opening op— posite the rotary disc, the exhaust gas is discharged out through an exhaust opening at the top of the machi ⁇ ne.
• This machine does thus not relate to any actual or particularly effective fluidization drying process and neither to a continuous process.
• the average axial flow rates of up—currents are between 1 to 3 m/s in the processing chamber, as the use of hig- her flow rates at most materials easily results in an excess of the terminal rate of fluidization, whereby a discharge of the incompletely processed material with the exhaust gas will take place.
• the object of the invention is to provide a process of the type stated in the introduction enabling a faster, more uniform, efficient and at the same time lenient disintegration and drying processing of heat-sensitive materials in particular.
• the disintegration and drying of the material currently fed is carried out as a continu ⁇ ous, intensive processing by — feeding the disintegration and drying gas to the pro ⁇ cessing chamber at high rate of speed as a turbulent, heavily rotating fluidization gas current by means of a drop of gas pressure maintained across the processing chamber and by means of a blade means arranged in the apparatus between the processing chamber and the blast box, said blade means having its inlet opening in flow connection with the blast box and its outlet leading to an annular area of the processing chamber defined by the chamber wall at the bottom thereof,
• the material fed does not settle at the bot ⁇ tom of the processing chamber, but is led up along the chamber wall by means of the fast rotating gas current as a thin fluidized layer in the full height of the chamber, preferably at a slight distance from the cham- ber wall during rotation, fast disintegration and dry— ing, whereupon a fraction of the processed material is discharged with the exhaust gas at the top of the appa ⁇ ratus, while the incompletely processed portion of the material containing partially dry lumps are led down- wards along the chamber wall and in the interior of the chamber, respectively. The portion carried downwards is caught again by the heavy up-current at the bottom of the chamber and thus subjected to a further disintegra ⁇ tion, earring upwards and drying.
• Yet another considerable advantage of the process accor ⁇ ding to the invention is that a considerably lower quan ⁇ tity of drying gas is used for the process, because of the improved fluidization rate and thermal efficiency.
• the physical dimensions of the apparatus may be reduced and as the connecting heating units for the drying gas, powder separators, filters and scrubbers primarily are dimensioned according to.the gas quantity flowing through the apparatus, the total initial expen ⁇ diture is considerably lower than previously.
• the inventive process is financially advantageous.
• the axial extension of the fluidized layer above the disintegrator is preferably larger than that of the dis- integrator, whereby the upper part of the chamber may function as an area uneffected by the disintegrator said area being used for grading the material according to the degree of drying and particle size.
• the disintegration and drying gas in varying quantities and/or at varying temperatures and/or gas compositions at different distances from the chamber wall, whereby a most appropriate variation of the gas current is provi ⁇ ded in the various areas of the proccessing chamber. It is thus possible, for instance close to the chamber wall, to provide a gas current, being more intensive and of a higher temperature than that further away from the wall, whereby the heavy, wet particles adjacent to the chamber wall, and particularly in the lower area there ⁇ of, are subjected to the most intense disintegration and drying effect, while the lighter, more dry fractions of the material further away from the chamber wall are sub- jected to a more gentle processing.
• a further improved turbulence in the gas current may for instance be obtained by at least sporadically feeding the disintegration and drying gas from successive blade interspaces of the blade means at different distances from the chamber wall.
• a blade means comprising a coaxially arranged, rotatable bladewheel or comprising several blade elements of which at least one is a coaxially arranged, rotatable blade element, and further, to adjust the rotational direction and speed of the rotatable blade means in accordance with the type and quantity of the material fed, whereby the effect of the blade means may be adjusted to the ma ⁇ terial to be processed, whereby the most advantageous combination of disintegration and drying is obtained.
• the process according to the invention may also be carried out using a blade means being completely or almost stopped, in which case the drop of gas pressure across the chamber may be adjusted.
• advantage ⁇ ous numbers of revolutions of the rotating blade means during processing for many purposes are the ones provid ⁇ ing the outer periphery thereof with tangential rates of speed between 1 m/s and 50 m/s , preferably between 2 m/s and 25 m/s, in particular between 2.5 m/s and 20 m/s, and when emptying the processing chamber, stopping the blade means .
• Advantageous numbers of revolutions of the disintegrator during processing are such providing the outer periphery thereof with tangential rates of speed between 5 m/s and 180 m/s, preferably between 10 m/s and 100 m/s, most preferred between 20 m/s and 50 m/s, and when emptying the processsing chamber, stopping or nearly stopping the disintegrator.
• Applicable drying gas temperatures may be ranging up to approximately 800 C C and at heat-sensitive materials preferably up to approximately 600 ⁇ C, in particular up to approximately 500°C. In many instances, this tempe ⁇ rature is considerably above the temperatures usable by the known processes.
• advantageous drops of gas pressure across the processing chamber for many purposes are such providing an axial average gas flow rate in the processing chamber of at least 3 m/s, most preferred 5 m/s, when the blade means and the dis ⁇ integrator are stopped and where the the axial average gas flow rate in the processing chamber is increased to at least 6 m/s, preferably at least 8 m/s, and most pre ⁇ ferred at least 10 m/s, preferably by means of the rota ⁇ ting blade means.
• the invention relates to an apparatus for carrying out the process according to the invention, said apparatus comprising a processing chamber having a chamber wall, the main shape thereof being substantially like a surface of revolution, and having an essentially vertical axis, and a subjacent blast box, and said ap ⁇ paratus comprises continuously acting means
• the means for continuous feeding of the disinte ⁇ gration and drying gas and the means for removal of the exhaust gas and the processed fraction of the material comprise an exhauster for maintaining a drop of gas pressure across the processing chamber, said exhauster being arrange-d*. in flow connection with the processing chamber through a discharge pipe, preferably extending into the processing chamber at the top thereof and a blade means arranged in the apparatus between the pro ⁇ cessing chamber and the blast box and having its inlet opening in flow connection with the blast box and its outlet leading to an annular area of the processing chamber defined by the chamber wall at the bottom there— of,
• the means for continuous agitation, mixing and disintegration comprise an intensively functioning, rotatable disintegrator coaxially arranged at the bottom of the processing chamber, said disintegrator preferably being provided with disintegrator means arranged above the blade means and projecting towards the chamber wall, - whereby the rotational direction as well as the num ⁇ bers of revoluations of the disintegrator, rotatable at high rate of speed, are adjustable.
• a particularly simple construction may consist in the blade means having the shape of a coaxially arranged blade wheel. This can either be non-pivotally or rotata— bly retained.
• the gas current in chamber assume the shape of an essentially stationary current flow with a speed profile retained relative to the processing chamber. The contribution of the blade wheel to the rotation of the gas current in the chamber is thus essentially a func ⁇ tion of the shape of the blade wheel in question.
• a rotation of the speed profile of the gas current is furthermore obtained in addition to an extra rotation of the gas current, re ⁇ sulting from the rotation of the blade wheel, and final ⁇ ly, a possibility for intensifying the gas current pro- vided that the blade wheel is shaped as a blower and the rotational speed is sufficiently high.
• the blade wheel may then be connected pivotally with the disintegrator and rotated with or without a gear ratio thereto or ad- vantageously rotated by means of a separate driven shaft, preferably a hollow shaft enclosing the disin ⁇ tegrator shaft and driven by means of a motor arranged outside of the blast box.
• the rotational speed of the blade wheel is regulated independently of the rotational speed of the disintegrator.
• the blade wheel may be driven by the gas current carried through the apparatus .
• the outlets from the successive ⁇ sive blade interspaces in the blade wheel may be arrang- ed at varying distances from the chamber wall by means of coverings and openings variedly arranged at the bla ⁇ des for the provision of a more irregular and conse ⁇ quently, more turbulent gas current in the processing chamber.
• the blade wheel may comprise blade interspaces, which together with the pertaining part of the inlet opening to the blade wheel each are divided into at least two flow channels by means of guide plates arranged therein and orientated in the flow direction.
• the flow channels may have varying channel cross sections and the outlets at different distances from the chamber wall.
• the gas flow from the same blade interspace is divided into currents flowing into the chamber at different di ⁇ stances from the chamber wall, and if so desired with varying intensity and direction and differing from those from other blade interspaces , whereby an additional tur ⁇ bulent current is produced in the processing chamber.
• the differently shaped flow channels may advantageously be connected to a separate gas sup- ply, whereby gas flows of varying compositions may be fed into the processing chamber at different places.
• This is particularly advantageous for feeding gas in larger quantities and/or with a higher drying capacity at the places in the processing chamber, where the most intensive disintegration and drying are required, parti ⁇ cularly close to the chamber wall, whereas gas in smal ⁇ ler quantities and/or with a lower drying capacity may be supplied further away from the chamber wall.
• the different flow channels may also be used for differentiating other forms for gas composi ⁇ tions, such as gas compositions low in oxygen in order to decrease the oxidation of the processed materials or other forms of inactive gas compositions or various types of solvents, which may further the disintegration.
• gas compositions low in oxygen such as gas compositions low in oxygen in order to decrease the oxidation of the processed materials or other forms of inactive gas compositions or various types of solvents, which may further the disintegration.
• the blade wheel as a blower
• the blade means may also be divided into at least two preferably annular blade ele ⁇ ments acting mutually independent.
• the same possibili ⁇ ties of variations and leading to the same advantages as for the above blade wheel is also valid for each of the blade elements.
• a blade means fitted and emplo- yed as a blower, as the resulting effect of a high gas flow rate and a subsequent intensive, turbulent flow generally is preferred.
• a blower of the centrifugal type or a hybrid between a centrifugal and an axial blower in which the outlet openings from the blade interspaces are turned upwardly in an annular area defined by the chamber wall at the bottom of the cham ⁇ ber.
• the air flow ejected from the individual outlet opening shows a speed profile with the highest speed at a point a short di- stance away from the chamber wall and from the posterior blade wall in the blade interspace, whereas the flow rate decreases abruptly towards the nearby walls (the chamber wall and the posterior blade wall, respectively) and evenly towards the other delimitations of the outlet opening. Consequently, the particles present within a certain distance above this area, particularly close to the chamber wall are subjected to pulsations of high frequency. The larger and heavier the particles, the more intensive the pulsations, whereby an intensive dis- integration and drying take place in this area.
• the structure of the disintegrator may be varied in many ways within the scope of the invention.
• the fast rotating disintegrator is throwing the material outside the central part of the blade means to the up-current at the chamber wall, in cases of larger and heavier particles into complete en ⁇ gagement with the chamber wall, at which they may be crushed.
• the disintegrator may advantageously be mounted on one end of a vertical shaft extending down through the blast box and operated by means of a separate motor arranged outside the blast box, whereby the motor is advantage ⁇ ously arranged outside the drying channel and a proces ⁇ sing chamber without impeding shafts is obtained.
• the processing chamber in its axial extension has a varied cross sectional shape, preferably a cross sectional shape widening upwards from the disintegrator area, most preferred a cross sectional shape widening upwardly from the disintegrator area and then narrowing.
• the axial extension of the processing chamber is substanti— ally larger and preferably more than twice as large as the axial extension of the disintegrator, as a satisfac ⁇ tory grading of particles prior to the extraction of the material may thereby be obtained together with a more efficient, uniform and lenient drying, as especially the processing at the top of the apparatus ensures a level ⁇ ling of variation in the residual moisture of the mate ⁇ rial .
• Fig. 1 is a diagrammatic view of a disintegration and drying system comprising the first embodiment of an ap- paratus for carrying out the process according to the invention
• Fig. 2 is a diagrammatic axial sectional view through another embodiment of the apparatus according to the invention.
• Fig. 3 is the same view as in Figure 2 with a dia ⁇ grammatic view of the flow pattern
• Fig. 4 is a partial, sectional view of a third embodi ⁇ ment of the apparatus according to the invention.
• Fig. 5 is a partial, sectional view of a fourth embodi- ment of the apparatus according to the invention with indication of the flow pattern in the apparatus,
• Fig. 6 is a partial, sectional view of a fifth embodi ⁇ ment of the apparatus according to the invention.
• Fig. 7 is a partial, sectional view of a sixth embodi- ment of the apparatus according to the invention.
• Fig. 8 is a partial, sectional view of a seventh embodi- ment of the apparatus according to the invention.
• Figs. 9a, b, c are views of a first blade wheel accord ⁇ ing to the invention, in a plan view (Fig. 9a), in a sectional view A—A (Fig. 9b) and in a partly axially sectional view (Fig. 9c), respectively,
• Figs. 10a, b, c are views of a second blade wheel accor ⁇ ding to the invention, in a plan view (Fig. 10a), in a sectional view A—A (Fig. 10b) and in a partly axially sectional view (Fig. 10c), respectively,
• Figs. 11a, b, c are views of a third blade wheel accord ⁇ ing to the invention, in a plan view (Fig. 11a), in a sectional view A-A (Fig. lib) and in a partly axially sectional view (Fig. lie), respectively,
• Figs. 12a, b, c are views of a fourth blade wheel accor- ding to the invention, in a plan view (Fig. 12a), in a sectional view A-A (Fig. 12b) and in a partly axially sectional view (Fig. 12c), respectively,
• Figs. 13a, b are diagrammatic views of the flow rate distribution in various cross sections of a radially arranged blade interspace (Fig. 13a), and the flow rate distribution above the successive outlets from such blade interspaces, as viewed in the direction of the arrows A—A of Fig. 13a, and
• Figs. 14a, b, c are diagrammatic views of the flow rate distribution in various cross sections of the successive blade interspaces in a blade wheel with outlets at two different distances from the chamber wall (Fig. 14a) (Fig. 14 b) , respectively, and (Fig. 14c) the flow rate distribution above successive outlets in said blade wheel, as viewed in the direction of the arrows A-A in Figs . 14a and 14b .
• Fig. 1 is a diagrammatic view of a disintegration and drying system of the type for carrying out the process according to the invention.
• the system comprises a dis ⁇ integration and drying apparatus (10) according to the invention, a feeding means (2) for feeding the material (1) to be processed into the apparatus (10) , a gas dis ⁇ tribution means comprising a filter (3), a heat exchan- ger (4) , a gas supply channel (5) leading to the appara ⁇ tus (10), and a discharge channel (6), a bag filter (7) having a bucket wheel feeder (8) for removing the pro ⁇ Listed material and an exhaust fan (9) for exhaustion of the filtered exhaust gas.
• a dis ⁇ integration and drying apparatus 10 according to the invention
• a feeding means (2) for feeding the material (1) to be processed into the apparatus (10)
• a gas dis ⁇ tribution means comprising a filter (3), a heat exchan- ger (4) , a gas supply channel (5) leading to the appara ⁇ tus (10), and a
• the disintegration and drying apparatus comprises a pro ⁇ cessing chamber (12) having a chamber wall (14) , the main shape thereof being substantially like a surface of revolution, and having a vertical axis, and a subjacent blast box (16).
• a coaxially arranged blower (18) is ar- ranged between the processing chamber (12) and the blast box (16), said blower having its central inlet opening (36) in flow connection with the blast box (16) and its outlet leading to the top surface of the blower (18) in an annular area (38) defined by the chamber wall (14).
• the blower is separately driven from a motor (28) out ⁇ side the blast box (16) through a hollow shaft (24).
• a rotatable, coaxially arranged disintegrator 20 is arran ⁇ ged above the blower (18), said disintegrator having an upper part (32) of an essentially circular, cylindrical form, on which disintegrator means (34) in form of swin ⁇ gles are arranged projecting towards the chamber wall (14).
• the disintegrator is mounted on the upper end of a shaft (26) passing through the hollow blower shaft (24) and separately driven from a motor (30) outside the blast box (16).
• a circumferential, horizontal division plate (22) is arranged below the blower (18) extending from the chamber wall (14) and into the inlet opening (36) of the blower (18).
• the exhaust fan (9), the blower (18), the disintegrator (20) and the feeding means (2) are driven continuously.
• the ex ⁇ haust fan (9) causes a drop of gas pressure across the processing chamber (12) which produces a gas flow through the system from the filter (3) to the exhaust fan (9) .
• This gas flow is intensified by the blower (18) additionally concentrating the gas flow into a thin, annular, rotating layer of an up—current having an in— tensive turbulence close to the chamber wall (14) .
• this gas current ensures a fast ' disintegration of the material (1) which is continuously being fed by means of the feeding means (2) through an opening (40) in the chamber wall (14) .
• the heavily disintegrated material is placed by the gas current as a fluidized, thin layer continuously ascen ⁇ ding and rotating, mainly along the chamber wall, where ⁇ by the smallest particles are dried quickly.
• the heavily disintegrated and partially dry material arrives at the top of the chamber (12) , the predominant portion of a processed fraction is removed with the exhaust gas, while a minor portion of said fraction together with the incomplely processed fraction is led slowly downwards along the chamber wall (14) and further into the proces— sing chamber (12) , until the material comes into contact with the disintegrator (20) and the intense gas current at the bottom of the chamber (12) , where it once again is subjected to a further disintegration and is carried upwards in the chamber (12) and dried, before another fraction is removed from the chamber.
• Figures 2 to 8 show a plurality of various embodiments of the disintegration and drying apparatus (10) accor- ding to the invention and details thereof, wherein the same reference numerals for the same parts have been used to a great extent. However, for some details devia ⁇ ting reference numerals have been used, if necessary by adding an index for mutual similar parts in order to emphasize differences of particular importance.
• FIG. 2 and 3 An apparatus (10) of a type similar to the one of Fig. 1 is thus shown in Figs. 2 and 3.
• the blower (18) and the disintegrator (20) are arranged on separately driven shafts (24,26), respectively, which are driven in the same manner as previously by means of motors (not shown) outside the blast box (16).
• the upper part (32) of the disintegrator (20) has, however, in this embodiment the form of an upwardly corbie—stepped cylinder and is pro ⁇ vided with swingles (34) of various lengths correspon- ding thereto.
• the lowermost part of the upper part (32) of the disintegrator thereby covers a larger section of the central part of the blower than the embodiment of Fig. 1.
• the radial extension of the blower (18) has fur ⁇ ther been made relatively shorter, and the underside of the blower has a profile being outwardly tapering to ⁇ wards the chamber wall (14), resulting in more ideal flow conditions through the blower (18).
• the division plate 22 under the blower (18) is down ⁇ wardly and inwardly inclined from the the chamber wall (14) , and thereby following the shape of the blower (18).
• Fig. 3 further illustrates by examples the ascending and decending motions of the gas flow in the chamber (12) by means of the arrows (42, 44, and 46, 48 and 50), respec ⁇ tively.
• This pattern of motion may vary depending upon the structural shape of the chamber and depending upon the ratio of the rotational to axial flow rate of the drying gas in the various cross sections of the chamber.
• Figs. 4 to 8 illustrate various embodiments of the dis ⁇ integrator (20) , the blade means (18) and the lower part of the chamber wall (14) in the area around these.
• the disintegrator is shown as a co ⁇ nical disintegrator (20').
• the disintegrator (20') is provided with four horizontally orientated, oblique, plate—shaped disintegrator arms (34) successi ⁇ vely arranged displaced at an angle of 90° relative to each other.
• Fig. 5 illustrates the disintegrator (20') without the disintegrator arms.
• the blade means is divided into two mutually independ ⁇ ently acting, coaxial blade elements (18' , 18") , that is a rotatable blade element (18') pivotally arranged with the upper part (32') of the disintegrator at the underside thereof and a subjacent likewise rotatable blade means (18"), rotatably mounted on its own hollow shaft (24), surrounding the shaft (26) of the disinte ⁇ grator (20').
• the blade element (18') on the disinte ⁇ grator (20') is of the same outer diameter as the upper part (32) of the disintegrator (20') and has an annular outlet (38') placed above the blade element (18").
• the blade element (18) extends further towards the chamber wall (14) and is of principally the same shape as the blade wheel or the blower (18) of Figs. 2 and 3 with an underside having an outwardly tapering profile abutting a division plate (22) parallel thereto and extending from the chamber wall (14) and defining the inlet ope ⁇ ning (36") to the blade element (18"). Furthermore, the blade element (18") has an inner annular element (36') situated in the same axial area as the innermost part of the blade element (18') on the disintegrator (20') and forming an inlet opening (36') for the blade element (18'). The element (36') is without flow connection to the rest of the blade element (18").
• the outlet from the blade element (18") is as at the blower (18) of Figs. 2 and 3, situated on the top surface of the blade element (18") in the annular area (38") at the periphery thereof between the chamber wall (14) and the outlet (38') from the blade element (18').
• Fig. 6 illustrates by example an annular blt.de wheel (18) attached to the chamber wall (14) .
• the wheel may be stationarily or rotatably attached and if so, it is driven by the disintegration and drying gas fed there ⁇ through from the blast box (16) .
• the disintegrator (20') is in this Fig. shown with its upper part (32') arranged within the blade wheel (18) and projecting thereabove.
• the disintegrator (20') has four sets of disintegrator arms (34'), the successive sets being arranged displaced at an angle of 90° relative to each other. Each set com— prises four horizontal arms (34,34') arranged on top of each other.
• the blade means is shaped as an annular blade wheel (18') attached pivotable to the disintegrator (20') at the underside of the upper part (32') thereof.
• the blade wheel (18') is of the same outer diameter as the upper part (32') of the disinte ⁇ grator and has its outlet (38') in the annular periphery thereof.
• a circumferential, horizontal division plate (22) extends from the chamber wall (14) just under the underside of the blade wheel (18') defining the inlet opening (36') thereto.
• the disintegrator (20') and the blade wheel (18') are in principle shaped as in Fig. 7, but have an upwardly tapering profile on the underside of the blade wheel (18').
• the chamber wall (14) is brought in under the blade wheel (18') parallel with and just below the bevelled part of the blade wheel (18').
• the disin ⁇ tegrator (20') of Figs. 7 and 8 is provided with four sets of disintegrator arms above each other, each set comprising four arms (34).
• the arms in Fig. 8 are pro ⁇ jecting further out at the top corresponding to the up ⁇ wards conically widening of the chamber (12) .
• the lower part of the processing chamber (12) opposite the blade means (18,18') and the disintegrator (20, 20') is cylindrically shaped.
• the cham ⁇ ber (12) is shaped upwardly conically widening from the division plate (22).
• the cham ⁇ ber (12) is shaped upwardly conically widening from the underside of the blade wheel (18') until being at level with the disintegrator (20'), then cylindrically shaped up to a level just above the disintegrator (20'), and thereabove upwards tapering.
• FIGs. 9 to 12 illustrate Examples of various embodiments of a blade wheel (18) according to the invention to be arranged above a division plate (22) , in all embodiments intended for mounting on a hollow shaft and provided with a through hole (42) for a disintegrator shaft.
• blades (44) are used attached to a top plate (46) and if necessary also to the wheel hub (48).
• Figs. 9a, b, and c illustrate a blade wheel (18), where the outlets from all of the blade interspaces are provi ⁇ ded at the periphery of the blade wheel simply by exten ⁇ ding the blades (44) radially slightly beyond the top plate (46). Every other blade is moreover shortened, so as not to extend completely into the wheel hub (48), whereby the flow resistance in the blade wheel (18) is decreased.
• the blade interspaces (50) are furthermore downwardly and radially outwardly open.
• a closure of these openings and thereby an increased effect of the blower are, however, obtained by placing the blade wheel (18) in a processing chamber (12) having an inner dia ⁇ meter only slightly larger than the diameter of the blade wheel and furthermore, having a division plate (22) extending parallel to the bevelled underside of the blades (44) shown in this Fig. , as it also appears in principle in Fig. 2 and Fig. 12.
• Figs. 10a, b, and c illustrate a similarly shaped blade wheel (18), wherein the top plate, however, every other blade interspace extends completely to the outermost end of the blades (44) , whereby the outlets from successive blade interspaces (50) alternately are only found at the cylindrical end surface of said blade interspaces, and in the intermediate interspaces, at the corresponding end surfaces and at the outer part of the top surface of said interspaces.
• the effect hereof is in practice that the successive outlets are found at varying distances from the chamber wall (14) , under the proviso that the blade wheel (18) is placed in a processing chamber (12) having a slightly larger diameter than the diameter of the blade wheel and having a subjacent division plate (22).
• Figs. 11a, b, and c illustrate another way to determine the placing of the blade outlets.
• the outlets from successive blade interspaces are radially displaced relative to each other, however, by every other blade interspace (50) being closed by means of a transverse plate (54) at a distance from the outer periphery of the blade wheel, and in addition hereto an outlet opening (52) is provided in the top plate (46) radially within the plate (54).
• the plate (54) may be L-shaped with an upper horizontal web flush with the top plate (46) as shown in Fig. lib. All of the blades (44) extend somewhat beyond the outer periphery of the top plate (46), whereby the outlets from the intermediate interspaces (50) are in the area extending on the out ⁇ side of the top plate (46) .
• Figs. 12a, b, c illustrate a blade wheel (18), wherein the outlets are arranged as in Figs. 11a, b, and c.
• each blade interspace and the subjacent inlet area are divided into two flow channels (51, 53) by means of fixed guiding plates (56) in each of the blade interspaces and by a circumferential fixed guide plate (58) in the subjacent blast box, arranged in extension thereto.
• Fig. 13a illustrates an Example of the distribution of the flow rate in various cross sections of a blade interspace and the outlet on the top surface thereof corresponding to a blade wheel as shown in principle in Fig. 9a, b, c, however, with a division plate (22) at ⁇ tached directly to the underside of the blade wheel and with slightly altered inlet conditions.
• the distribution of the flow rate is illustrated by means of velocity vectors as shown at the inlet, in the middle of the blade interspace and at the outlet thereof.
• the velocity vectors shown partly illustrate the increasing flow rate out through the blade interspace until the outlet there ⁇ of at the chamber wall (14), and partly the distribution of the axial flow rate in the radial direction at the outlet, said flow rate abruptly increasing from a value close to zero at the chamber wall to a maximum value at a short distance from the chamber wall and then slowly decreasing to a minimum value at the innermost edge of the outlet opening.
• Fig. 13b illustrates the distribution of the axial flow rate in the tangential direction at the outlets for the successive blade interspaces seen in direction of the arrows A-A in Fig. 13a under the pro ⁇ viso that the blade wheel as seen in the direction men ⁇ tioned rotates to the right relative to the Fig. 13b.
• the distribution of the flow rate is uneven, also when seen in this direction, whereby the highest outlet flow rate is found at a short distance from the blades (44) advancing the air and with an abruptly decreasing flow rate towards this blade and with a more evenly decreasing flow rate down to a mini ⁇ mum value at the leading blade (44) in the blade inter ⁇ space (50) in question.
• the gas flow is provided with a flow rate component in the tangential direction resulting from the rotation of the blade wheel, which naturally provide the particles with a rotary motion, but does not, however, influence the principle of the aforemen ⁇ tioned reflections about the influences to which the particles are subjected.
• the particles being close to the outlet openings are thus subjected to more or less intensive pulsations.
• Figs. 14a, b, and c illustra ⁇ te the distribution of the flow rate in a blade wheel (18) and above the outlet openings thereof, wherein the outlets in successive blade interspaces (50) are mutual- ly radially displaced and thus is found at different distances from the chamber wall (14), as it appears from Figs. 14a and 14b.
• Fig. lib Fig.
• the process and apparatus according to the invention has proved particularly advantageous for the disintegration and drying of organic material which is particularly sensitive to heat and especially for the disintegration and drying of materials to be used as fodder or food ⁇ stuffs.
• the following Examples are based on a test run of a pilot plant and illustrate the advantages obtained by means of the process and the apparatus according to the invention.
• Disintegration and drying of a press cake of organic material with a moisture content of 50% calculated on the wet weight was carried out. Heated atmospheric air was used for the drying.
• an appara ⁇ tus according to the invention comprising a blower of a diameter of 250 mm and thirty—six evenly dispersed, radially arranged blades and a disintegrator with a conical upper part and sixteen horizontal disin ⁇ tegrator arms in form of swingles displaced in sets at the angle of 90° .
• the numbers of revoluations of the blower was 1000 r.p.m, whereby the air at the chamber wall opposite the ventilator was provided with a tangential flow rate of approximately 13 m/s .
• the average axial air flow rate in the processing chamber was about eight m/s in the Exam ⁇ ple, rendering peak values of 20 m/s or more at the chamber wall as a result of the special flow rate pro— file for the air flow out of each individual blade in ⁇ terspace in the blower.
• the absolute peak value for the air flow rate was thus about 24 m/s , which in the drying area ensured substantial heat tranfer coefficient be ⁇ tween the drying air and the product which were inten- sively agitated, mixed and disintegrated by the disin ⁇ tegrator.
• the inlet temperature was 400°C.
• the outlet temperature was 120°C and a powder residue moisture of 4 percent calculated on the wet weight was thereby obtained.
• the capacity was 33 kg/h.
• the blower was stopped, whereafter the residual moisture increased to 8 percent water calculated on the wet weight, and the capacity decreased to 28.5 kg/h. Concurrently, the outlet temperature increased to 130°C, and the product showed signs of incipient heat damage.
• the effect of the blower is thus essential for the dry ⁇ ing effect and for the capacity as well as for the qua- lity of the product.
• the ratio of the differences in tempe ⁇ rature between the inlet and the outlet drying air broadly represents the drying capacity, and also the in ⁇ verse ratio of the required drying air flows formulated as follows :
• the air flow is approximately four times lower at the process according the invention.
• the physical dimen— sions of the system according to the invention are fur ⁇ ther much smaller.
• the connected air heaters and the powder separators, including filters and any air washers primarily dimensioned according to the volume of air passing through the system are also considerably smaller, whereby the total costs of construction are lower at the new process.
• the differences in the thermal efficiency demonstrate distinct deviations in the operating costs in favour of the present invention.
• the cleaning costs are reduced, as the system can be completely emptied automatically by stopping the feeding of the product, whereby cleaning is made prac ⁇ tically superfluous.
• the dis ⁇ integration and drying apparatus according to the inven- tion may be sterilized immediately by flowing hot drying air through the apparatus prior to feeding the new pro ⁇ duct into the system. This feature is particularly vital when dealing with foodstuffs systems.
• the very short processing time of the product in the apparatus according to the invention permits the use of the selected temperatures without heat damaging the product, this in spite of the air tem ⁇ peratures utilized at the prior art both to and fro the fluidized bed being lower, but the processing time here- of is on the other hand several minutes.
• a third portion of the pre-treated product (product C3) was dried in the apparatus according to the invention at an inlet air temperature of 400°C and an outlet air tem ⁇ perature of 120°C at atmospheric pressure.
• concentration of essential amino acids present in the dried powder has been used, calculated in percentages of the total solid matter in the product.
• the results found for the pro ⁇ ducts mentioned Cl, C2 , and C3 are stated in the below table, in which also the capacity of water absorption of the products C2 and C3 is indicated measured as absorb- able amount of water in gram per 100 g solid matter. It appears from the table that the content of essential amino acid was 9.7% higher and in total content of amino acid was 7.6% higher in the powder dried by means of the process according to the invention (C3) as compared to the powder dried at a low temperature (C2) .
• hood temperature in this connection means the condensation temperature of the heating medium.

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• Life Sciences & Earth Sciences (AREA)
• Microbiology (AREA)
• Drying Of Solid Materials (AREA)

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• 1991
  • 1991-01-21 DK DK9891A patent/DK9891A/da unknown
• 1992
  • 1992-01-21 WO PCT/DK1992/000018 patent/WO1992012796A1/en active IP Right Grant
  • 1992-01-21 DE DE69204277T patent/DE69204277T2/de not_active Expired - Fee Related
  • 1992-01-21 DK DK92904291T patent/DK0567560T3/da active
  • 1992-01-21 AU AU12022/92A patent/AU1202292A/en not_active Abandoned
  • 1992-01-21 EP EP92904291A patent/EP0567560B1/en not_active Expired - Lifetime

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