The invention relates to a dosing apparatus for dosing powdery, granular or flaked substances.
The invention particularly relates to a dosing apparatus intended for dispensing, in a continuous or discontinuous manner, metered quantities of bulk products in the solid and dry state, i.e. not pasty nor emulsified.
The dosing apparatus for powdery, granular or flaked according to the invention is particularly suitable for being used in the chemical industry as well as in the livestock, pharmaceutical or food industry. Uses of the dosing apparatus according to the invention other than those mentioned above may be also provided.
The dosing apparatuses of the known type comprise a containment compartment for containing powdery, granular or flaked substances. Two devices are arranged internally of the containment compartment i.e. an homogenizing device and a dosing device. The homogenizing device prepares the substance and makes it uniform, whilst the dosing device calibrates the amount of substance coming out of the dosing apparatus according to a predetermined operation scheme established by this apparatus. The known dosing apparatuses described above are defined single screw, as they are provided with only one dosing device, or metering screw.
The homogenizing device is arranged in the vicinity of a feeding mouth, wherefrom the powdery, granular or flaked substance derives. It comprises a support rod rotatable about its own longitudinal axis and provided with a plurality of vanes for mixing and/or aerating the powdery, granular or flaked substance. The dosing device is instead disposed downstream the homogenizing device and is configured for dispensing the powdery, granular or flaked substance in a dosed manner.
The dosing device, which is also rotatable about its own longitudinal axis, may comprise a shaft on which a helix is wound. During the rotation, the dosing device acts as a calibrated screw feeder in which at each revolution of the shaft a precise substance quantity corresponds that is dispensed at the outlet of the dosing apparatus.
During operation, the single-screw dosing apparatuses of the known type are positioned in such a way that a vertical plane which contains the longitudinal axis of the homogenizing device, also contains the longitudinal axis of the dosing device, In other words, the homogenizing device and the dosing device extend along respective axes which lie on a common vertical plane.
A drawback of known dosing apparatuses is that the powdery, granular or flaked substance tends to accumulate above the dosing device, thus forming bridge-shaped structures which may extend along the entire length of the containment compartment. This goes to the detriment of homogenization uniformity, affects proper dosage of the outcoming substance and may give rise to contamination or deterioration of those products, such as food products, that need to be dosed based on precise timescales.
In this context, the technical task of the present invention is to make available an apparatus for dosing powdery, granular or flaked substances which overcomes the above mentioned drawbacks as well as any use restrictions that may result therefrom.
It is an object of the present invention to make available a dosing apparatus for dosing powdery, granular or flaked substances, which is effective and allows to perform homogenisation and dosage of a powdery, granular or flaked substances in a repeatable and reliable manner.
These and other objects are substantially attained by a dosing apparatus for powdery, granular or flaked substances according to what is disclosed in one or more of the appended claims.
The dependent claims correspond to further embodiments of a dosing apparatus for powdery, granular or flaked substances in accordance with the present invention.
Further characteristics and advantages will become more apparent from the detailed description of a preferred and non-exclusive embodiment of a dosing apparatus for dosing powdery, granular or flaked substances.
Such description is provided with reference to the accompanying figures, also being illustrated as a non-limiting example wherein:
With reference to
The dosing apparatus 1 comprises a dosing device 10 and an homogenizing device 20, as schematically illustrated for example in
The homogenizing device 20 and the dosing device 10 are operatively associated with one another in an operating configuration of the dosing apparatus 1. In particular, the homogenizing device 20 is rotatable about an axis of rotation “Y”.
The dosing device 10 is rotatable about a further axis of rotation “X” and extends along this axis. The dosing device 10 has a first end 11 and a second end 12.
Preferably, the axis of rotation “X” of the dosing device 10 is parallel to the axis of rotation “Y” of the homogenizing device 20.
The dosing apparatus 1 comprises a containment chamber 30 delimited by a first end wall 31 and a second end wall 32 facing each other and arranged transversely, in particular perpendicularly, with respect to the axis of rotation “Y” of the homogenizing device 20. The second end wall 32 may be at least partially defined by a port 40, which can be removed for example thanks to the fastening means 41 visible in
The containment chamber 30 is further delimited by a side junction surface 33 that extends between the first end wall 31 and the second end wall 32 along a direction of development “T” parallel to the axis of rotation “X.
The containment chamber 30 exhibits rounded edges, so as to make the surface of this chamber as far as possible devoid of sharp edges or stagnation corners generated by the powdery, granular or flaked substance. This makes more efficient the emptying of the containment chamber 30 and allows to attain an improved cleaning of the dosing apparatus 1, both because it is more difficult that stagnations arising from the substance to be dosed are formed outside the dosing apparatus 1, and because the dosing apparatus 1 can be easily washed, in particular with water, without having the washing water stagnating in the proximity of the sharp edges of the dosing apparatus 1.
Preferably, the containment chamber 30 exhibits its own upper portion 30a, a feeding mouth 34 which is connectable, for example by means of a flanged portion, to a feeder or a hopper (not shown) for the transport of powdery, granular or flaked substances, within the dosing apparatus 1. The containment chamber 30 further exhibits a lower portion 30b, at which the powdery, granular or flaked substances deposit in an operative configuration of the dosing apparatus 1.
Preferably, as shown in
In a version not shown, the rounded portion 33b may exhibit, in a cross section taken along a plane perpendicular to the axis of rotation “Y”, a non-constant radius of curvature. In the latter case, the rounded portion 33b can be defined by a plurality of curvilinear portions shaped in such a way as to progressively come closer to the homogenizing device 20, by passing from the upper portion 30a to the lower portion 30b.
In other words, the rounded portion 33b may be shaped in such a way as to exhibit a greater distance from the homogenizing device 20 in the area where this portion extends along a direction close to the vertical direction, and instead to exhibit a lesser distance from the homogenizing device 20 in the area where the rounded portion 33b extends along a substantially horizontal direction. In this way, any stagnation of the processed substance is prevented.
The homogenizing device 20 is installed on the dosing apparatus 1 in an intermediate region of the containment chamber 30, as better described hereinafter. In particular, the homogenizing device 20 is arranged so as to occupy a main portion 38 of the containment chamber 30.
The containment chamber 30 further exhibits a housing 35 for housing, at least partially, the dosing device 10. The housing 35 develops starting from the first end wall 31 until the second end wall 32 along the development direction “T”.
In the example shown, the housing 35 is afforded internally of a protuberance 39 that is protruding from the rounded portion 33b of the side surface 33. It is however, also possible to consider a case where the containment chamber 30 is delimited by walls having a thickness such that the housing 35 can be obtained within the thickness of such walls. In this case, it is not possible to identify any protuberance 39 projecting outwardly.
The housing 35 is configured so as to house the dosing apparatus 10. A passage space 36, shown in
In particular, the passage space 36 extends along the development direction “T” for a length equal to the distance that exists between the first end wall 31 and the second end wall 32 of the containment chamber 30. The housing 35 is disposed in the vicinity of the rounded portion 33b of the side surface 33. More in detail, the housing 35 and the rounded portion 33b are interposed between the facing sections 33a of the side surface 33. Between the rounded portion 33b and the housing 35 there is provided a connecting zone 42 which is so shaped as to promote the sliding of the powdery, granular or flaked substance from the rounded portion 33b towards the housing 35. In particular, the connecting portion 42 is devoid of sharp edges.
The first end 11 of the dosing device 10 is disposed at the first wall 31 of the containment chamber 30.
As shown in
The outlet mouth 2 is substantially an opening from which the powdery, granular or flaked substance is coming out after interacting with the homogenizing device 20 and with the dosing device 10.
In the example depicted, the extraction portion 13 of the dosing device 10 is facing the passage space 36 of the containment chamber 30. The passage space 36 has, along a direction transversal to the development direction 7″, a proportionate width to a measure of an outer diameter ID″ of the dosing device 10.
The dosing apparatus 1 comprises positioning means 50, shown in
The housing 35 protrudes downwardly from the lower portion 30b of the containment chamber 30.
The housing 35, and the dosing device 10 arranged internally thereof, is disposed in a lateral position with respect to the axis of rotation “Y” of the homogenizing device 20. In other words, as shown in the appended
The housing 35 is delimited by an inner curved surface 35a, with respect to the containment chamber 30, that is adapted to fit together at least partially with a respective portion of the dosing device 10.
By the term internal curved surface 35a it is meant a surface portion arranged internally of the housing 35, which is facing the containment chamber 30, that is to say, it is in direct contact with the powdery/granular/flaked substance in an operative configuration of the dosing apparatus 1. Preferably, the curved surface 35a has a radius of curvature approximately equal to the outer diameter “D” of the dosing device 10.
The housing 35 is also delimited by a flat surface 35b which, in the operative configuration of the dosing apparatus 1, is arranged substantially vertically. The flat surface 35b extends tangentially from the curved surface 35a up to a portion of the side surface 33 of the containment chamber 30, as shown schematically in
Preferably, the flat surface 35b is incident to a portion of the side surface 33 and acts as a connection wall between the housing 35 and the side surface 33 of the containment chamber 30.
The homogenizing device 20 is provided with a plurality of mixing or aeration vanes 21 of fixed on an attachment portion 22 of the homogenizing device 20.
The plurality of vanes 21 may comprise two end vanes 21a disposed in proximity of the first end wall 31 and respectively of the second end wall 32 of the containment chamber 30. The end vanes 21a exhibit a relatively simple shape, and can be substantially flat and arranged obliquely with respect to the axis of rotation “Y”. The end vanes 21a have the function to converge the powdery, granular or flaked substance to be dosed towards a central region of the containment chamber 30.
The plurality of mixing vanes 21 may further comprise a plurality of vanes in the form of a ploughshare 21b, Preferably, the vanes in the form of a ploughshare 21b are interposed between the end vanes 21a. The walls which delimit the containment chamber 30 can be made entirely of metal, or entirely of plastic material, or still can be provided with a plastic material coating.
To the walls of the containment chamber 30, if made of a plastic material, one or more facilitators devices can be associated, for facilitating the descent of the product, for example vibrators or oscillators of the electric or pneumatic type, or they may be associated to mechanical vanes, for causing the walls of the containment chamber 30 to vibrate and help the processed substance to flow towards the outlet, or more precisely towards the dosing device 10. The facilitators devices facilitating the descent of the product can be applied on the outside of the walls of the containment chamber 30 or integrated at least partially within the thickness of these walls.
The apparatus dosing device 1 allows to substantially reduce the accumulation of the substance to be dosed above the dosing device 10, compared with known dosing apparatuses. In fact, by moving laterally the dosing device 10 relative to the homogenizing device 20, the powdery, granular or flaked substance can more easily be conducted towards the outlet mouth 2 while rotating the dosing apparatus 10.
This effect is amplified by the flat surface 35b of the housing 35. In fact, the powdery, granular or flaked substance which is transported upwards during rotation of the dosing apparatus 10, is not able to adhere to the flat surface 35b, which is disposed substantially vertically, but rather tends to slide downwards, thereby detaching from the flat surface 35b. Thus, in this way, the powdery, granular or flaked substance interacts again with the dosing device 10, which transports the latter towards the outlet mouth 2. In the example described with reference to
The two dosing devices of the twin-screw apparatus are interconnected and self-cleaning. They can be separated by a small insert of a substantially triangular section, designed to fill a void space present between the homogenizing devices, below the latter.
Furthermore, the present invention has achieved the intended aims by making available a more efficient dosing apparatus, which is able to accurately carry out a homogenization and dosing process of a bulk substance, repeatable at every operating regime of the same.
In addition, the present invention provides a dosing apparatus capable of homogenizing the bulk substance contained internally thereof, without any accumulations, thus preventing formation of aggregations and residues arising from the processed substance, thereby ensuring high dosing accuracy and ease of cleaning.
Number | Date | Country | Kind |
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202015000038926 | Jul 2015 | IT | national |