NO177415B

NO177415B - Mixes with double curved blades

Info

Publication number: NO177415B
Application number: NO931642A
Authority: NO
Inventors: Geir Nordahl
Original assignee: Geir Nordahl
Priority date: 1994-11-03
Filing date: 1993-05-05
Publication date: 1995-06-06
Also published as: NO177415C; UA29496C2; HUT76177A; HU221158B1; EP0738182B1; DE69422732D1; CA2180136A1; NO931642L; CZ226896A3; JPH09510661A; HU9602102D0; PL176493B1; DE69422732T2; WO1996014142A1; BR9408468A; PT738182E; AU1285095A; NO931642D0; DK0738182T3; EP0738182A1

Abstract

Blade for a mixing device, especially for the mixing of different particles or different liquids, for the arrangement on substantially horizontal rotors, where each blade comprises a first surface with a curvature facing the direction of the motion for the particles and in the radial direction the blades shape has straight lines arranged perpendicularly to the rotor axis, where the curved blade comprises a first portion (3) facing in the direction of motion of the masses, a second, substantially smaller portion (4) facing opposite the direction of motion, and a portion lying in between and connecting the two aforementioned portions, extending substantially parallel with the rotor axis, in such a way that the substantial portion of the masses are thrown forwards, whereas a smaller portion is thrown radially outwards and respectively backwards, the particles thereby being mixed with particles being thrown forwards from the following blade.

Description

Foreliggende oppfinnelse angår en skovl for en blandeanordning, ifølge kravinnledningen. The present invention relates to a paddle for a mixing device, according to the preamble.

Blandere av denne type benyttes innenfor mange fagom-råder for sammenblanding av to eller flere ulike bestanddeler av partikler eller væsker eller en kombinasjon av disse, til en ønsket grad av homogenitet. De enkelte bestanddeler tilføres i doserte mengder og kan være væsker som skal sammenblandes, partikler med mer eller mindre ulik beskaffenhet, som skal blandes, væske som skal tilsettes partikler eller liknende. Slike blandere benyttes også for tørking av partikler og likeledes for frysing av partikler, enten som egne prosesser eller som del av en blandeprosess. Mixers of this type are used in many specialist areas for mixing two or more different components of particles or liquids or a combination of these, to a desired degree of homogeneity. The individual components are supplied in metered quantities and can be liquids to be mixed together, particles of more or less different nature, to be mixed, liquid to be added to particles or the like. Such mixers are also used for drying particles and likewise for freezing particles, either as separate processes or as part of a mixing process.

Blandere av ovennevnte type arbeider med skovler montert på rotorer, hvor skovlenes form og plassering bevirker at massene kastes opp og blandes samtidig med at de bringes fremover i blanderen. Det er naturligvis viktig at den såkalte kastekurve er optimalisert, for dermed å oppnå best mulig blanding og samtidig den ønskede transport. Det er tidligere benyttet plane skovler og man har forsøkt å endre skovlenes vinkel i forhold til rotoraksen samt andre parametre som rotorens turtall, skovlenes lengde etc for å optimalisere blandeprosessen. Mixers of the above type work with paddles mounted on rotors, where the shape and position of the paddles cause the masses to be thrown up and mixed at the same time as they are brought forward in the mixer. It is naturally important that the so-called throw curve is optimised, in order to achieve the best possible mixing and at the same time the desired transport. Plane blades have previously been used and attempts have been made to change the angle of the blades in relation to the rotor axis as well as other parameters such as the speed of the rotor, the length of the blades etc. in order to optimize the mixing process.

Det er nå funnet at blandeprosessen kan optimaliseres ytterligere ved utformingen av skovlene, samtidig som det også oppnås andre fordeler. It has now been found that the mixing process can be further optimized by the design of the paddles, while other benefits are also achieved.

Dette oppnås med skovlen ifølge foreliggende oppfinnelse, slik den er definert med de i kravene anførte trekk. This is achieved with the shovel according to the present invention, as defined by the features listed in the claims.

På tegningen viser figur 1 skjematisk et enderiss av en blander med to rotorer, figur 2 viser et sideriss mot rotoraksen av en skovlform og figur 3 viser et tilsvarende riss av en noe endret skovlform. In the drawing, figure 1 schematically shows an end view of a mixer with two rotors, figure 2 shows a side view towards the rotor axis of a blade shape and figure 3 shows a corresponding drawing of a somewhat changed blade shape.

Ved utformingen av skovl 1 eksempelvis som del av et rør, kan et slikt rør hensiktsmessig deles i fire segmenter, hver tilsvarende 90° og hvor hvert segment festes til rotoren som vist på figur 2, dreid en vinkel a i forhold til rotoraksen. Vinkelen a kan hensiktsmessig være 20°, noe som medfører at en del av massene påvirkes av skovlbladets fremre del 3 og en del påvirkes av den bakre del 4. Skovlbladets krumme form medfører en stor spredning av de masser som kastes opp og delvis også en tilbake-føring i forhold til blanderens transportretning, nemlig av de masser som gripes av den bakre del 4. When designing vane 1, for example, as part of a tube, such a tube can be conveniently divided into four segments, each corresponding to 90° and where each segment is attached to the rotor as shown in Figure 2, turned an angle a in relation to the rotor axis. The angle a can suitably be 20°, which means that part of the masses are affected by the front part 3 of the blade and part is affected by the rear part 4. The curved shape of the blade leads to a large spread of the masses that are thrown up and partly also a back - guidance in relation to the transport direction of the mixer, namely of the masses that are gripped by the rear part 4.

Skovlens ytre periferi er hensiktsmessig bøyd opp til en flens 2 eller påsatt en flens 2, enten som en kontinuerlig kurve eller som en stump vinkel til skovlbladet. The outer periphery of the blade is suitably bent up into a flange 2 or attached to a flange 2, either as a continuous curve or as an obtuse angle to the blade.

Flensen 2 bevirker at massen som kastes radialt ut langs skovlbladet 1, treffer flensen 2 og endrer dermed sin kastebane. Videre er det vesentlig at den masse som kastes radialt ut langs skovlbladet 1 i stor utstrekning vil treffe flensen 2 og dermed endre sin retning og fremfor alt ikke treffe beholderens bunn. Dette medfører at slitasje mot beholderens bunn minskes, noe som kan være av vesentlig betydning, avhengig av de masser som benyttes i prosessen. The flange 2 causes the mass which is thrown radially out along the blade 1 to hit the flange 2 and thus change its throwing path. Furthermore, it is essential that the mass which is thrown radially out along the blade 1 to a large extent will hit the flange 2 and thus change its direction and above all not hit the bottom of the container. This means that wear and tear on the bottom of the container is reduced, which can be of significant importance, depending on the materials used in the process.

Figur 3 viser skjematisk en annen utførelse av en krum skovl, nemlig i tverrsnitt ikke som del av en sirkel, men med en buet flate hvor den bakre del 4 fremdeles er bibeholdt for å oppnå større spredning av massene, også stasjonært og dels bakover i forhold til rotoraksen. Slik det fremgår av tegningen er det videre lagt vekt å bibeholde en krum skovlflate for dermed å oppnå en stor spredning av massene og en optimalisert, stor kastekurve 5, slik det fremgår av figur 1. Figure 3 schematically shows another embodiment of a curved blade, namely in cross-section not as part of a circle, but with a curved surface where the rear part 4 is still retained in order to achieve greater dispersion of the masses, also stationary and partly backwards in relation to the rotor axis. As can be seen from the drawing, emphasis has also been placed on maintaining a curved blade surface in order to achieve a large spread of the masses and an optimised, large throw curve 5, as can be seen in figure 1.

Claims

1. Vane for a mixing device, in particular for mixing particulate or liquid masses, for mounting on essentially horizontally positioned rotors, where each vane has a first single curved surface facing the direction of movement of the masses and whose straight lines run perpendicular to the rotor axis, CHARACTERIZED BY that the curved part of the vanes comprises a first part (3) which faces in the direction of movement of the masses, a second, significantly smaller part (4) which faces opposite to the direction of movement of the masses, and an intermediate part connecting them essentially parallel to the rotor shaft, so that the most significant

part of the mass is thrown forward, while smaller parts that are thrown radially out and backwards are mixed with masses that are thrown forward from behind the vanes.

2. Bucket according to claim 1, CHARACTERIZED IN THAT the outer periphery of the buckets comprises a flange (2) which in the direction of movement of the masses forms an obtuse angle with the rest of the bucket and which essentially extends over the entire axial length of the buckets.