Patent Description:
In particular, the invention relates to a rotating screen apparatus for the selection of bulk solid materials of various kinds, different degrees of humidity, and possibly including liquid substances. Preferably, the rotary screen apparatus according to the invention is configured to select, and therefore separate from each other, grains or pieces in general of materials having the same or even different nature, but different granulometry and dimensions.

The use of different types of screens, which for example can be vibrating, rotating, etc., is known for the selection of bulk materials which have different grain sizes and/or different percentages of humidity.

In particular, the rotating screens are used to carry out the selection of different types of materials with different dimensions.

More specifically, in order to select solid materials, the rotating screens have perforated/perforated selection walls through which the finer materials pass while the coarser ones are retained. In particular, it is known the use of rotating screens equipped with rigid networks or rigid perforated panels of various types, metal (for example, perforated plates) or polymeric, with holes of various shapes (square, rectangular, round, etc.).

Currently, the separated materials that pass through and exit the sorting side walls of the rotating screen are collected/conveyed by a fixed hopper, which is positioned below the screen on a conveyor belt, to be then removed from the plant and/or reused.

Conveniently, in order to collect/convey all the material that comes out of the separating walls of the screen, the fixed hopper must have real dimensions - and in particular length and width - substantially corresponding to those of the screen itself. Furthermore, in the event that the material has high contents of liquids and/or in the case of materials with high humidity, the walls of the hopper are particularly inclined - ie close to the vertical - to prevent the material from packing on the walls themselves, clogging the hopper. However, in this case, the unloading of the fixed hopper has dimensions substantially corresponding (or in any case slightly lower) to those of the inlet and, therefore, the conveyor belt provided in correspondence with the unloading itself has important dimensions, and in any case it is oversized compared to the volume of material to be transported. In particular, to unload the material on a conveyor belt of adequate size for the volume to be transported, the hopper will have an important development in height and, the smaller the volume of the material to be transported, the greater and oversized will be the height of the unloading hopper.

For example, a rotating screen <NUM> meters long which is equipped with a fixed hopper whose height is in line with the spaces available below said screen, requires a conveyor belt, positioned near the discharge, at least <NUM>,<NUM> meters wide.

Unfortunately, this involves a greater bulk of the conveyor belt and therefore the need to provide (or in any case have available) more space under and/or downstream of the rotating screen, as well as involving greater electrical consumption for the movement of such a conveyor belt. Furthermore, the use of large conveyor belts inevitably entails an undesirable increase in the relative costs.

<CIT> shows a separation apparatus which comprises an internal drum and an external drum, both cylindrical in shape and provided with respective and dedicated rotation means which operate individually and independently from each other.

The object of the invention is to propose an apparatus for the selection of bulk materials which allows to overcome, at least in part, the drawbacks of the known solutions.

Another object of the invention is to propose an apparatus which allows to select/separate materials with a high moisture content and/or liquids.

Another object of the invention is to propose an apparatus which allows to select/separate particularly dirty materials.

Another object of the invention is to propose an apparatus that allows to select/separate semi-solid or sticky materials.

Another object of the invention is to propose an apparatus that allows to select/separate black or white slag deriving from the steel refining processes.

Another object of the invention is to propose an apparatus which allows to reduce the necessary maintenance.

Another object of the invention is to propose an apparatus with reduced overall dimensions.

Another object of the invention is to propose an apparatus which is alternative and/or improved with respect to the known solutions.

Another object of the invention is to propose an apparatus which has an alternative structural and/or functional configuration with respect to traditional solutions.

Another object of the invention is to propose an apparatus which can be implemented in a simple, rapid and low-cost manner.

All these objects, both individually and in any combination thereof, and others which will result from the following description, are achieved, according to the invention, with an apparatus having the characteristics indicated in claim <NUM>.

The present invention is further clarified hereinafter in some of its preferred embodiments and in some executive variants, reported for purely illustrative and nonlimiting purposes with reference to the attached drawings, in which:.

As can be seen from the figures, the present invention relates to a rotary screen apparatus <NUM> for the selection of bulk materials.

Conveniently, the apparatus <NUM> can be used for the selection of materials which can be in the solid state, with different granulometry. Furthermore, said materials to be selected can comprise quantities of humidity and/or water and/or other liquids in variable proportions. Preferably, the apparatus <NUM> is configured to select, and therefore separate from each other, grains or pieces in general of the same material but with different granulometry, and in particular dimensions, different. Conveniently, the apparatus <NUM> can also be used to select, and therefore separate, different types of materials with different dimensions. Preferably but not exclusively, the apparatus <NUM> can be used to select slag, in particular white or black slag, deriving from the steel refining process.

The apparatus <NUM> according to the invention is rotatably rotating around an X axis.

Conveniently, the apparatus <NUM> comprises a selection/separation surface <NUM> rotatable around the X axis.

The selection/separation surface <NUM> has a substantially tubular development (ie cylindrical or frusto-conical) and delimits an internal chamber <NUM> which is separated, from said selection surface <NUM>, from an external zone <NUM>.

Conveniently, said external zone <NUM> has an annular conformation and is defined externally around the selection surface <NUM>.

The apparatus <NUM> according to the invention also comprises at least one conveyor element <NUM>, which has a flared annular shape oriented along the X axis and which is rotating, and in particular is pivotally rotatable about the X axis. Preferably, said at least one conveyor element <NUM> has a conformation corresponding to the lateral surface of a truncated cone or a truncated pyramid, with a height that extends along the X axis.

Conveniently, said at least one conveyor element <NUM> is mounted around said selection surface <NUM> to convey outwards the selected material that has crossed the selection surface <NUM>.

More in detail, below, the X axis corresponds to the axis of longitudinal development of the rotating selection apparatus <NUM>, and in particular of the selection surface <NUM>. In particular, the X axis corresponds to the axis around which the selection apparatus <NUM> rotates, and in particular around which both the selection surface <NUM> and said at least one conveyor element <NUM> rotate. The X axis can be substantially horizontal and/or can be inclined with respect to the horizontal. The Y axis corresponds to the radial development direction of the selection apparatus and, conveniently, is perpendicular to the X axis.

Conveniently, said at least one conveyor element <NUM> is integral with the selection/separation surface <NUM> in the rotation rotatable around the X axis.

In particular, said at least conveyor element <NUM> rotates together with the selection/separation surface <NUM> and, suitably, is configured to direct the material that emerges from said selection/separation surface <NUM> towards transport or collection means (not represented).

Conveniently, said at least one conveyor element <NUM> can be configured to have a load-bearing and structural function.

Preferably, said at least one conveyor element <NUM> is positioned around the selection surface <NUM> so that its widest portion faces the central area of the selection surface.

Preferably, the apparatus comprises two conveying elements <NUM> having a flared shape arranged so that its most widened extremal portions face each other.

Advantageously, in a possible embodiment (see <FIG> and <FIG>) the flared conveyor elements <NUM> are spaced apart so as to define an empty central portion between them.

Advantageously, in another possible embodiment (see <FIG>), the flared conveyor elements <NUM> are connected to each other by a central cylindrical annular portion <NUM>, to thus define an envelope around the selection surface <NUM>.

Advantageously, in correspondence with the central cylindrical annular portion <NUM> which joins the two flared conveyor elements, passages <NUM> can be provided for the exit of the selected material towards the outside, in particular towards a transport and/or unloading area external to the apparatus <NUM>.

The internal chamber <NUM> is intended to receive the material to be selected, while said external zone <NUM> is intended to receive the material selected following the passage through the through holes/meshes defined in said selection surface <NUM>. In particular, the selected material comprises the material which, having dimensions smaller than the through holes/meshes of the selection surface <NUM>, managed to pass through said surface. Conveniently, the selected material crosses radially (ie along the Y direction) the selection surface <NUM>.

Conveniently, at least a part of the selected material falls by gravity onto the flared conveyor element <NUM> which is rotatably rotating around the X axis integrally with said surface selection <NUM>, to convey it towards a further zone (internal or external to the apparatus) or towards the external environment, preferably towards a conveyor belt or a collection zone positioned below the apparatus <NUM>.

Conveniently, at least a part of the material selected can fall by gravity directly outside the apparatus <NUM> and, in particular, this can take place in correspondence with the area of the selection surface <NUM> not vertically aligned with an underlying conveyor element <NUM>.

Preferably, the selection surface <NUM> can comprise a plurality of selection panels <NUM> side by side in sequence along the circular extension of the surface itself. Conveniently, said selection panels <NUM> can be made of a rigid material (metal, for example they are defined by a perforated sheet, or polymeric) or of an elastically flexible material.

Conveniently, said internal chamber <NUM> comprises an inlet opening <NUM>' for the material to be separated, and an outlet opening <NUM>" for the material which has not passed through the selection surface <NUM>, in particular as it is larger than the through holes/meshes obtained in said selection surface <NUM>. Preferably, the two openings <NUM>' and <NUM>" face each other and are defined at the two opposite bases of a tubular structure whose lateral surface is defined by/comprises said selection surface <NUM>.

Preferably, the apparatus <NUM> according to the invention can comprise a rotating support frame <NUM>, in particular rotating around the X axis.

Conveniently, said at least one conveyor element <NUM> is integral in rotation with the support frame <NUM>.

Conveniently, said at least one conveyor element <NUM> is mounted externally on the frame <NUM> and, preferably, has the widest flared portion oriented towards the central area of the frame.

Conveniently, the support frame <NUM> defines the skeleton of a tubular structure which, as a whole, can be substantially cylindrical or substantially frusto-conical, or which - in general - can have the shape substantially of a solid of rotation.

Preferably, the frame <NUM> and said at least one conveyor element <NUM> rotate around the X axis which is substantially horizontal or inclined with respect to the horizontal, in particular by an angle preferably of at least <NUM>° with respect to the horizontal, preferably equal to or lower at about <NUM>°. In particular, for this purpose, means (not shown) are provided for activating the rotation of said frame <NUM> and therefore of the conveyor element <NUM> around the X axis. Advantageously, said means can be configured and/or controlled to modify the rotation speed of the frame <NUM> and the conveyor element <NUM>.

Advantageously, the frame <NUM> is made of metallic material, preferably of carbon steel.

Advantageously, the frame <NUM> comprises two annular bases <NUM>' and <NUM>" facing each other. Conveniently, the two annular bases <NUM>' and <NUM>" can have substantially the same dimensions or they could have different dimensions. Conveniently, the frame <NUM> can also comprise a plurality of longitudinal members <NUM> fixed at their respective ends to the internal/facing sides of the annular bases <NUM>, <NUM>' and spaced along the annular extension of said bases.

Conveniently, on the frame <NUM>, and in particular on the longitudinal members <NUM>, selection panels <NUM> are installed - which define said selection surface <NUM> - configured to select the material, in particular to separate the coarser material from the finer one. Preferably, the selection panels <NUM> are mounted on said frame <NUM> side by side so as to substantially define the whole, or most of the lateral surface of said tubular structure. Preferably, the selection panels <NUM> are rigidly fixed on said frame <NUM> or are mounted so as to be floating, in particular in the radial direction (ie along the Y axis). Preferably, the selection panels <NUM> define the selection surface <NUM>.

Conveniently, the frame <NUM> and/or the conveyor element <NUM> can comprise a connecting flange (which for example corresponds to the annular base <NUM>' illustrated in the figures) with a rotating structure (not shown), for example with a corresponding section of a rotating cylindrical cooling reactor.

Conveniently, said at least one conveyor element <NUM> can be made of rigid and resistant materials, for example it can be made of metal, for example carbon steel, alloy steel or stainless steel, or of polymeric material or metal material coated with polymeric material (for example carbon steel coated with polymer material). Advantageously, in a possible embodiment, the conveyor element <NUM> can be made of flexible material, preferably elastically flexible, so as to modify its concavity following its rotational rotation around the X axis, and this in order to avoid that the separated material sticks to its inner surface.

Preferably, in a possible embodiment (see <FIG> and <FIG>), the apparatus <NUM> comprises at least one further conveyor element <NUM> which has the same structural characteristics described above for said at least one conveyor element <NUM> and which is positioned around the selection surface <NUM> so that its widest portion is facing (at least in part) outside the selection surface <NUM>. Conveniently, the further conveyor element <NUM> is mounted around said selection surface <NUM> so that its most widened end portion faces outside the selection surface <NUM> in order to convey the material outwards in the internal chamber <NUM> which did not cross the selection surface <NUM>. Conveniently, said further conveyor element <NUM> is provided/mounted in correspondence of the outlet opening <NUM>" of the internal chamber <NUM> and is flared towards the outside. Conveniently, said further conveyor element <NUM> is flared towards the direction of advancement/crossing of the material inside the internal chamber <NUM> from the inlet opening <NUM>' towards the outlet opening <NUM>".

Advantageously, said at least one conveyor element <NUM> and/or said further conveyor element <NUM> comprises/comprise, at the internal surface of the frusto-conical wall, a non-stick and/or water-repellent and/or oil-repellent coating.

Conveniently, in a possible embodiment, the conveyor element <NUM> and/or said further conveyor element <NUM> it can / they can have a flat and continuous surface (without holes or undulations) along its/their annular/circumferential development, or it can / they can have a surface that is wavy along its/their annular/circumferential development.

Advantageously, the frusto-conical wall of said at least one conveyor element <NUM> and/or said further conveyor element <NUM> is inclined with respect to the X axis by an angle lower than about <NUM>°. Preferably, the frusto-conical wall of said at least one conveyor element <NUM> and/or of said further conveyor element <NUM> is inclined by an angle greater than about <NUM>° with respect to the horizontal or in any case greater than the maximum inclination angle of the apparatus with respect to the horizontal. Conveniently, this allows to reduce (thanks to the fact that said elements <NUM> and/or <NUM> are rotating) the height dimensions of said conveyor elements <NUM> and/or <NUM>, and/or the dimensions of the conveyor belt.

Conveniently, each conveyor element <NUM> and/or said further conveyor element <NUM> are removably associated with the selection surface <NUM>, preferably with a frame <NUM> of said selection surface <NUM>. More in detail, each conveyor element <NUM> and/or said further conveyor element <NUM> are associated with the selection surface <NUM>, and in particular with the frame <NUM>, in a removable way, for example by means of screws (or other traditional mechanical fastening members) or by means of interlocking mechanisms, to allow their maintenance or replacement in case of wear.

From what has been said it is clear that the apparatus according to the invention is advantageous, indeed optimal, since:.

The apparatus according to the present invention finds application preferentially but not limitedly in the recycling of solid bulk materials of various kinds, for example for the treatment of white or black slag deriving from the steel refining process, in all sites / contexts of extraction and processing of mining material of various kinds, as well as in general in industrial sectors where bulk solid material is dealt with.

In particular, the term "white slag" refers to a waste resulting from the refining processes of a metal alloy, in particular of steel, during the production chain of the alloy itself, in particular of steel. In particular, white slag is a waste material very rich in lime and/or other binders and therefore advantageously recoverable. With the term black slag we mean the slag that forms, above the steel melting bath, as a result of the oxidation of the scrap and of the compounds generated by the additives inserted in the charge of the electric furnace to produce steel starting from the scrap; suitably, this slag is discharged at the outlet from the electric furnace to be treated in a separate and dedicated way with respect to the liquid steel.

Advantageously, the apparatus according to the invention can be mounted in a rotating tubular reactor for the treatment of white or black slag of the type described in <CIT> or in <CIT> or in the <CIT>.

Claim 1:
Apparatus (<NUM>) for the selection of materials, in particular of the type operating with a rotating screen, comprising:
- a selection surface (<NUM>), which is rotatably rotating around an X axis which is horizontal or inclined with respect to the horizontal, which has a substantially tubular development and which internally delimits an internal chamber (<NUM>) which is separated from said selection surface (<NUM>), from an external zone (<NUM>), said internal chamber (<NUM>) being destined to receive the material to be selected and said external zone (<NUM>) being destined to receive the selected material following the passage through through holes/meshes of said selection surface (<NUM>), and
characterized in that it comprises:
- at least one rotating conveyor element (<NUM>), which has a flared annular conformation oriented along the X axis, is integral with said selection surface (<NUM>) in its rotation rotatable around the X axis and is mounted around said selection surface (<NUM>) to convey outwards the selected material that has crossed the selection surface (<NUM>).