Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B3/00—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements
  • B05B3/001—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements incorporating means for heating or cooling, e.g. the material to be sprayed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B3/00—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements
  • B05B3/02—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements
  • B05B3/10—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces
  • B05B3/1007—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces characterised by the rotating member
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B3/00—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements
  • B05B3/02—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements
  • B05B3/10—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces
  • B05B3/1071—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces with two rotating members rotating at different speeds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B3/00—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements
  • B05B3/02—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements
  • B05B3/10—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces
  • B05B3/1071—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces with two rotating members rotating at different speeds
  • B05B3/1078—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements discharging over substantially the whole periphery of the rotating member, i.e. the spraying being effected by centrifugal forces with two rotating members rotating at different speeds the rotating members rotating in opposite directions

Definitions

• the present invention relates to a method and an apparatus for dividing a liquid into droplets. More particularly, the invention relates to droplet formation, methods and apparatuses of the type where droplets are slung from a droplet formation apparatus by centrifugal action.
• One application of the invention is the formation of nonyielding spherical granules from a liquid mate ⁇ rial, such as a melt, during which the droplets formed according to the invention are slung by centrifugal action in the nonsolidified state from a droplet forma ⁇ tion apparatus and are subsequently subjected, for examp ⁇ le in a descending motion, to a solidification process in a solidification zone.
• a liquid mate ⁇ rial such as a melt
• melt is used hereinafter for all types of substances in liquid or semiliquid form, optional ⁇ ly containing suspended or dispersed particles capable of solidifying (for example by changes in temperature, drying or chemical processes) into spherical granules during their subsequent passage through a solidifica ⁇ tion zone.
• the droplets are formed of a liquid which does not undergo solidifica ⁇ tion after the droplet formation.
• One such application is, for example, gas purification of the type in which the gas to be purified is caused to pass through a "cloud" of liquid droplets removing impurities from the gas.
• Another application is painting/spray painting.
• air-drying and the distribution of fuel in burners may be mentioned as examples of conceivable applications of this invention.
• the prior art technique within the first-mentioned application of the invention i.e. the formation of spherical granules from a melt, comprises for example the production of urea for fertilizers, carbamide and ammonium nitrate, where it is desired to have a final product in the form of small spherical granules.
• a great many droplet formation methods and apparatuses have been developed for this purpose, the main object of which was to produce uniform size spheres, i.e. uniform size droplets of the melt.
• Such droplet formation appa ⁇ ratuses are usually mounted in the upper part of a so- called prilling tower through which a cooling air flow is directed upwards against the descending droplets.
• a more uniform diameter relationship of such droplets implies a number of production and environmental improve ⁇ ments.
• Spreading the droplet diameter implies that the material must be re elted to a large extent.
• undersized droplets could give rise to undesired air pollutants because the under ⁇ sized droplets are carried along in the form of aerosols by the exhaust air and cause odour problems in the sur ⁇ roundings, fallout, and other environmental hazards.
• Many known production methods and droplet forma ⁇ tion apparatuses are based on the principle that a melt is supplied to a perforated and, optionally, rotating cylindrical surface or the like which they leave in the form of droplets.
• SE 7206000-7 proposes, for example, that the passages in a droplet-forming disk should be coated with a layer of epoxy plastic to prevent clogging of the droplet-for ⁇ ming passages .
• SE 7402820-0 discloses the use of a rotating perfo- rated container from which a melt is slung out through radial holes in the container wall and thus is divided into droplets.
• the liquid material is supplied in the form of annular laminar flows, each individual flow being conducted towards vertically spaced apart areas comprising rows of holes.
• NO 170,270 endeavours to solve the above-mentioned clogging problem by means of a centrifuge for spraying liquid material, such as a melt, through a rotating perforated wall, the container of the centrifuge accom ⁇ modating a body which presents rotation symmetry and whose surface facing the centrifuge wall has essentially the same form of rotation as the wall of the centrifuge container, said body being so dimensioned that there is formed, between the body and the inside of the cen ⁇ trifuge container, a relatively narrow annular space having a width of, for example, 20 mm.
• the patent also proposes that the said inner body be formed with discharge openings, such that a melt can be introduced into the interior of the body from above and flow out through the discharge openings into the annular space and from there through the perforations of the centrifuge contai- ner -
• melt particles slung from the disk are more or less drop-shaped because particles slung from a perforated rotating surface are formed by cutting off jets or threads from the melt, whereby the final product obtains an undesired nonspherical shape.
• a third disadvantage of the prior technique of forming droplets from a melt is that the amount of droplet material cannot be controlled per unit of time, while simultaneously maintaining an unchanged droplet size.
• liquid as used above and hereinafter shall be considered to comprise all liquid or semiliquid materials permitting the formation of droplets according to the invention.
• liquid shall be considered to comprise also such melts as have been defined above.
• the novel characteristic feature of the invention is that the liquid in the drop formation apparatus from which the droplets are slung by centrifugal action, is uniformly distributed in the circumferential direction relative to a geometrical axis on a disk, preferably several associated disks rotatable about said axis, the peripheral outer edge of each disk being provided with circumferentially equidistant, uniform and radially projecting portions called cusps hereinafter.
• the disk or disks are caused to rotate during discharge of the liquid, such that the liquid discharged onto each disk is formed into a uniform thick- ness film which, under centrifugal action, spreads radi ⁇ ally outwardly towards said cusps and is divided thereby into uniform size droplets.
• each droplet will detach itself from the corresponding cusp when, as a result of the increasing droplet size, the centri- fugal force acting outwardly on the droplet, exceeds the corresponding inwardly directed force of adhesion.
• the term "cusp” compri ⁇ ses also other types of radially projecting portions than conventional "saw-toothed" pointed cusps.
• the term "cusp” must be taken to comprise also (a) ra ⁇ dially projecting closely spaced rods or the like, (b) radially projecting unpointed bulges, for example a wave-shaped peripheral edge of the disk or disks, (c) radially projecting portions whose height perpendicular to the plane of the disk is less than the thickness of the disk, which can be achieved for example by mounting two circular disks which have the same diameter and one of which has a periphery provided with cusps, while the other has a smooth periphery, with their main surfaces facing one another and with the cusp-bearing disk upper ⁇ most, such that the points of the cusps coincide with the peripheral edge of the lower disk, and (d) other radially projecting portions providing the liquid distri ⁇ bution effect according to the invention.
• the invention also comprises a droplet formation apparatus of the type mentioned by way of introduction, said apparatus being intended for the above-mentioned droplet formation method and being characterised by: a disk means comprising at least one disk which is rotatable about a geometrical axis preferably per ⁇ pendicular to the extent of the disk and whose outer peripheral edge is provided with circumferential equi- distant, uniform and radially projecting portions de ⁇ signated cusps hereinbelow; a distributing means adapted to distribute the liquid uniformly in the circumferential direction about the said axis, on the disk or disks of said disk means; and drive means connected with the said disk means and adapted to cause said disk means to rotate about the axis during distribution of the liquid, such that the liquid discharged onto the disk or disks is formed into a uniform thickness film which spreads radially outwardly towards the said cusps and is divided thereby into uniform size droplets.
• a disk means comprising at least one disk which is rotatable about a geometrical
• the apparatus is characterised in that said disk means comprises a plurality of axially spaced apart and mutually held-together disks of the said type, said disks being provided each with a central opening, and that said distributing means comprises a dosing cylinder which is rotationally independent of said disk means and extended through the central openings of the disks, the circumferential wall of said dosing cylinder being formed with at least one, preferably several dosing openings at each disk.
• the dosing cylind ⁇ er is preferably caused to rotate at a speed different from the speed of rotation of the disk means. This can be achieved for example by rotating the distributing means and the disk means in opposite directions.
• the disk means and the distributing means are mutually rotated because this is a prior condi- tion for supplying each point on the radially inner portions of the disks with a continuous liquid flow from the dosing openings. If the dosing openings do not rotate relative to the disks, only those points on the disks that lie outside a dosing opening will be supplied with a continuous liquid flow, and the result is a less uniform spread of the liquid film on each disk.
• a stationary cylind ⁇ er adapted to receive the liquid and having an outer diameter which is smaller than the inner- diameter of the dosing cylinder, is coaxially mounted in the dosing cylinder, such that an annular space is formed between the inner stationary receiving cylinder and the rotating dosing cylinder.
• the circumferential wall of the inner cylinder has a plurality of substantially axially directed slots through which the liquid flows out into the annular space. The liquid forms, by centrifugal action, a layer on the inside of the rotating dosing cylinder, and the liquid in this layer is successively dosed out through the dosing openings onto the disks.
• a prior condition for uniform size droplets is that the amount of liquid dosed onto the disks is constant in time. This is achieved if the thickness of the said layer is maintained constant in time.
• the stationary inner cylinder is provided, at each slot formed therein, with a radially projecting land on the side of the slot located in the direction of rotation of the dosing cylind ⁇ er. These lands have a radial extent which is smaller than the width of said angular space, whereby the thick ⁇ ness of the liquid layer is limited to the distance between the lands and the inside of the dosing cylinder.
• the slot/land combination will also function as automa ⁇ tic throttling valves, as will be described in more detail hereinafter.
• this known technique which at first sight may seem to be near to the present invention, has an entirely different function and appli ⁇ cation and, besides, an entirely different purpose than the droplet formation apparatus according to the inven ⁇ tion.
• the material supplied to the disk solidifies while on the disk, and this must not be confused with the technique of the present invention, according to which the liquid supplied to the disk or disks is- not solidified while it is on the disk. Indeed it is a prior condition for the droplet formation by the peripheral notches of the disk or disks that they receive the mate ⁇ rial in the liquid state and divide it into droplets which leave the droplet formation apparatus in the liquid state.
• a further difference between the technique disclosed by WO 82/03024 and the technique of the present invention is that the latter effects an active distribution of the liquid in the circumferential direction on each disk, which is a prior condition for producing on each disk 'a liquid film which is absolutely uniform in thick ⁇ ness, and this in turn is a prior condition for a uniform and constant flow to the notches, such that uniform size droplets are formed.
• the WO publication does not disclose such an active distribution of the metal melt in the circumferential direction, and the metal melt is supplied to the disk at one point only which is spaced from the disk centre.
• the prior art according to WO 82/03024 is remote from the present invention, both in technical respect and in respect of its application.
• Fig. 1 is a longitudinal section of a first embodiment of a droplet formation apparatus according to the invention
• Fig. 2 is a cross-sectional view along line II-II of the apparatus shown in Fig. 1
• Fig. 3 is a cross-sectional view along line III-III of the apparatus shown in Fig. 1
• Fig. 4 is a longitudinal section of a second enbodiment of a droplet formation apparatus according to the in- vention
• Fig. 5 is a cross-section along line V-V of the apparatus shown in Fig. 4.
• Figs. 1-3 illustrating a first preferred embodiment of a droplet formation apparatus according to the invention.
• This apparatus is especially useful for that application of the inven ⁇ tion where nonyielding spherical granules are to be formed from a melt.
• the apparatus can be supplied with, for example, a melt, such as urea, and can divide the melt into uniform size droplets which in the nonsolidified state are slung out by centrifugal action from the appa ⁇ ratus and solidify during their subsequent passage through a solidification zone.
• the droplet formation apparatus illustrated may be mounted e.g. at the top of a so-called prilling tower (not shown) .through which cooling air is flowing in order to dry the descending droplets slung out by the droplet formation apparatus.
• the droplet formation apparatus of Fig. 1 comprises three principal means, viz. a stationary receiving means generally designated 10, a rotatable distributing and dosing means generally designated 20, and a rotatable disk means generally designated 30. These three principal means 10, 20 and 30 are mounted concentrically and in a compact manner about a vertical geometrical axis A.
• the stationary receiving means 10 comprises an upper circular cylindrical inlet container 11 which, via peripheral openings, communicates with inlet ducts 12, as shown in Fig. 1, and an outlet container 13 located beneath the inlet container 11 and formed with an annular inner space defined by a cylinder 14, a radial bottom 15 and a pipe 16 which is concentric with the axis A.
• the inner annular space of the outlet container 13 com ⁇ municates with the inlet container 11 via a central opening 17 formed in the latter.
• the pipe 16 which in the embodiment illustrated is stationary, also extends upwardly through the inlet container 11, as shown in Fig. 1.
• the cylindrical circumferential wall 14 of the outlet container 13 is formed with a number of elongate vertical outlet slots 18 uniformly distributed around the circumference of the cylinder 14. As will be seen from Fig. 3, the embodiment illustrated has eight outlet slots 18.
• the cylindrical circumferential wall 14 of the outlet container 13 is provided with vertical and radially projecting lands 19, the number of which corresponds to the number of slots 18.
• the lands 19 are provided on the outside of the cylinder 14 at and in parallel with each of said outlet slots 18. In the embodiment illustrated, the lands 19 are provided on but one side of each slot 18 but in other embodiments such lands may be provided, if desired, on both sides of the slots 18. The function of the lands 19 will be described here- inbelow.
• the rotatable distributing and dosing means 20 • consists substantially of a rotatable dosing container
• the driving pipe 24 is mounted rotatably and concentrically within the stationary pipe 16, and the inner diameter of the circumferential wall 22 is larger than the outer diameter of the inner cylinder 14, such that there is formed, between the stationary outlet container 13 of the re ⁇ DCVing means 10 and the rotating circumferential wall
• the driving pipe 24 of the distributing means 20 is fixedly connected with a first driving wheel 25 adapted to be drivingly connected with driving means (not shown) for rotating the distributing means about the axis A, as shown by the arrow Pi in Fig. 3.
• the cylindrical circumferential wall 22 of the dosing cylinder 21 is formed with a number of axial y ' spaced apart horizontal rows of dosing openings 26 which constitute discharge openings from the annular space in the dosing container 21.
• each such horizontal row of dosing openings 26 comprises .six equidistantly distributed dosing openings, as shown in Fig. 3.
• the rotatable disk means 30, finally, comprises a rotatable driving shaft 31 which is rotatably mounted within the rotatable driving pipe 24 and which, at its - upper end, is fixedly connected with a second driving wheel 32, a hub 33 mounted at the lower end of the driving shaft 31 and radially extended below the bottom 23 of the dosing container 21, a plurality of circumferentially distributed, axially directed rods 34 received with their lower ends 34a in openings formed in the hub 33 at a radial distance from the cylindrical circumferential wall 22 of the dosing container 21, and a number of horizontal annular disks 35, the number of which corre ⁇ sponds to the number of rows -of dosing openings 26, said disks being supported by said rods 34 in a given spaced apart relationship, and each disk having a hori- zontal outer portion 35a and an inner downwardly directed conical portion 35b associated with
• the melt is ' introduced through the inlet ducts 12 into the inlet container 11 and flows by gravity down into the stationary outlet container 13 and out through the outlet slots 18.
• the disk means 30 which comprises the second driving wheel 32, the driving shaft 31, the hub 33, the rods 34 and the disks 35, is caused to rotate by means of the driving means not shown, but in a direction of rotation P2 which is opposite to the direction of rotation P1 of the distributing means.20, as is shown in Fig. 3.
• the melt in the outlet container 13 will thus flow through the outlet slots 18 out into the dosing container
• the arrangement of the vertical slots and the rotat ⁇ ing dosing container 21 thus provides, on the inside of the circumferential wall 22, a melt layer which is of uniform thickness both vertically and circumferen ⁇ tially, and- this in turn implies that the outward flow through the dosing openings 26 will be substantially constant in time and of uniform size for the dosin ⁇ openings 26 at different levels.
• the stationary inner cylinder 14 is pro ⁇ vided with the above-mentioned lands 19 at the outlet slots 18.
• the radial extent of the lands 19 is smaller than the radial width of the annular space in the dosing container 21, as will appear from Fig. 3.
• the lands 19 are mounted on that side of the slots 18 which lies in the direction of rotation P1. In this manner, the lands 19 in con- junction with the slots 18 will function as automatic throttling valves.
• a land 19 comes into contact with the said layer, a form of "turbulence” is generated immediately outside the corresponding slot 18, whereby further melt discharge through the slot is prevented, and the flow through the "valve” is throttled.
• the thickness of the layer is then reduced, because of the outward flow through the dosing opening 2.6, the "valve” will be reopened automatically. In this manner, there is always maintained a constant thickness of melt layer on the inside of the circumferential wall 22, i.e. a constant outward flow through the dosing openings 26.
• the disks 35 of the disk means 30 are rotating during operation of the apparatus, although in a direction (P2) opposite to that of the dosing container 21.
• P2 a direction opposite to that of the dosing container 21.
• each disk 35 thus is supplied with a circumferentially continuous flow of melt which is formed, by the * rotation of the disk (in the direction P2), inter a continuous uniform thickness film which grows outwardly towards the cusps at the outer peripheral edge of the disk 35 and is divided by said cusps into uniform size droplets.
• a droplet is formed which, while still in the molten state, detaches itself from the cusp when the outwardly directed centrifugal force acting on the droplet exceeds the inwardly directed force of adhesion on the droplet, which occurs when the droplet, formed on the cusp has attained a given desired size.
• the droplet dimension can be calculated empirically from the following equation: d - 1 wherein:
• the droplet formation apparatus described with reference to Figs. 1-3 is suit ⁇ able for the production of nonyielding spherical granules from a melt.
• it is frequently desired to produce a large total volume or weight of droplets per unit of time, for example in the order of 10 tons/ hour.
• the droplets may in ⁇ stead be desired to produce a large number of relative ⁇ ly smaller droplets per unit of time, but with an essen- tially lower liquid flow through the apparatus than in the first case.
• the droplet formation apparatus as shown in Figs. 1-3 is less suitable for smaller liquid flows, for the following reason: In the droplet formation apparatus according to
• Figs. 1-3 it is a condition for uniform size droplets that a constant thickness of the liquid layer on the inside of the circumferential wall 22 is maintained because otherwise there will be no constant outward flow through the dosing openings 26, i.e. a uniform thickness layer on the disks. If the flow through the apparatus is reduced considerably, the liquid layer on the inside of the rotating circumferential wall 22 will be so thin that it is difficult or impossible to maintain a constant layer thickness, and this in turn means that the uniform distribution of the liquid on the disks, which is necessary for uniform size droplets, it not obtained.
• the invention proposes a second embodiment of a droplet formation apparatus which is especially suitable for producing, from a smaller liquid flow, a large number of relatively small droplets per unit of time.
• a droplet formation apparatus of this type will now be described in more detail with refe- rence to Figs. 4 and 5.
• those parts of Figs. 4 and 5 which occur already in Figs. 1-3 and have essentially the same function, have been given the same reference numerals, plus 100.
• the droplet formation apparatus of Fig. 4 comprises three principal means, viz.
• the stationary receiving means 110 comprises a bearing housing 150 with an inner duct 151 concentric with the shaft A.
• the bearing housing 150 is provided with a hose nipple 152 which is in liquid communication with an inner bore 153 in the bearing housing.
• the bore 153 extends from the radially inner end of the hose nipple 152 to an opening 154 in one end 155 of the bearing housing 150.
• the bearing housing has a radial recess 156.
• the rotatable distributing and dosing means 120 consists essentially of a rotatable cylinder 122 having a bottom 123 at its end facing away from the receiving means 110, a supporting disk 160 at its other end, and a driving pipe 124 which is fixedly connected with the cylinder 122 via the bottom 123 and the supporting disk 160.
• the driving pipe 124 is rotatably mounted concent ⁇ rically within the inner duct 151 of the bearing housing 150 via bearings 161 and 162. Furthermore, the driving pipe 124 is fixedly connected, at its left-hand end in Fig. 4, with a belt pulley 125 which is driven by driving means (not shown) for rotation of the dosing means 120.
• the interior of the cylinder 122 is conical, the wider part facing away from the receiving means 110.
• the conical inner surface has a number of circumferen- tially uniformly spaced apart, identical grooves 163.
• Each groove 163 is defined at one end by the bottom 123 and at the other end by an angular cover disk 164.
• the cover disk 164 has a central conical hole 165 accom ⁇ modating the narrow end 155, 156 of the bearing housing 150.
• Each groove 63 communicates with a radial dosing duct 126 formed in the cylinder 122.
• the dosing ducts 126 are uniformly distributed both circumferentially and axially.
• the rotatable disk means 130 -finally, comprises a rotatable driving shaft 131 rotatably mounted within the driving pipe 124, by means .of bearings 166, 167.
• the driving shaft is fixedly connected at one end with a belt pulley 132, a hub 133 mounted at the other end of the driving shaft 131 and radially extended below the bottom 123 of the cylinder 122, a number of cir- cumferentially distributed rods 134 accommodated at one end 134a in openings formed in the hub 133 at a radial distance from the cylinder 122, and a plurality of annular disks 135, the number of which, as seen in the axial direction, corresponds to the number of dosing ducts 126.
• the disks 135 have essentially the same ap ⁇ pearance as the disks 35 in the embodiment according to Figs. 1-3 and are therefore not described in detail.
• the dosing ducts 126 open at the liquid-receiving surfaces of the disks 135.
• the apparatus according to Figs. 4 and 5 has forty-eight grooves 163 and twelve disks 135. In the embodiment illustrated, each groove 163 "serves" but one disk 135, which means that there are forty-eight dosing ducts 126, which gives four ducts 126 per disk.
• the apparatus shown in Figs. 4 and 5 is used for the formation of liquid droplets, the liquid is introduced through the hose nipple 152 to the bore 153 in the stationary bearing housing 150 from which the liquid flows out through the opening 154 and into the cylinder 122.
• the dosing means 120 and the disk means 130 are caused to rotate both relative to one another and relative to the receiving means 110.
• the speed of rotation of the cylinder 122 is sufficiently high, or in other words if the centrifugal force acting on the liquid .within the cylinder 122 is sufficiently large, the liquid exiting through the opening 154 will be collected by the grooves 163 for further conveyance to the dosing ducts 126.
• the liquid flow will be divided uniformly in the grooves 163, and if the speed of rotation of the dosing means 120 is sufficiently high, a balanced liquid flow will leave the dosing ducts 126 and flow to the disks 135.
• a radially outwardly growing liquid film of uniform thickness is obtainable on each disk 135, which is a prerequisite for uniform size drop ⁇ lets.
• the second embodiment of the invention thus makes it possible, in spite of a small liquid flow, to maintain a constant and uniformly distributed liquid flow to the disks.
• Such a flow is obtained by substituting for the liquid film at the circumferential wall 22 a number of separate liquid flows which are controlled by the grooves 163 and led to the individual dosing ducts 126.
• Figs 4 and 5 also illustrate a number of "fan blades" 170 fixedly mounted on and radially projecting from the rotating cylinder 122. In this manner, there is obtained, upon operation on the apparatus, an axial air flow adapted to act upon, for example, a gas which is conducted past the apparatus for purification.
• the embodiments described above of the droplet formation apparatus according to the invention can be modified in many ways within the scope of the invention which is limited only by the appended claims. According to one such modification, the apparatus may comprise but one disk if lower capacity is desired.

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• Nozzles (AREA)
• Manufacturing Of Micro-Capsules (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20368005

Family Applications (1)

Country Status (9)

Cited By (7)

Families Citing this family (13)

Citations (4)

Family Cites Families (7)

• 1987
  • 1987-03-27 SE SE8701274A patent/SE456486B/sv not_active IP Right Cessation
• 1988
  • 1988-03-25 JP JP63502858A patent/JPH0634949B2/ja not_active Expired - Fee Related
  • 1988-03-25 US US07/411,478 patent/US4978069A/en not_active Expired - Lifetime
  • 1988-03-25 WO PCT/SE1988/000145 patent/WO1988007414A1/en active IP Right Grant
  • 1988-03-25 AU AU14938/88A patent/AU1493888A/en not_active Abandoned
  • 1988-03-25 DE DE3885284T patent/DE3885284T2/de not_active Expired - Fee Related
  • 1988-03-25 EP EP88902980A patent/EP0368851B1/en not_active Expired - Lifetime
  • 1988-11-25 DK DK661688A patent/DK170712B1/da not_active IP Right Cessation
• 1989
  • 1989-09-26 FI FI894548A patent/FI100642B/sv not_active IP Right Cessation

Patent Citations (4)

Non-Patent Citations (2)

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