GB2035141A - Machine for cleaning and/or sorting loose materials - Google Patents

Abstract

A machine for cleaning and/or sorting loose materials comprises at least one cleaning and/or sorting unit (1) having a hollow casing (5) which is secured to a frame (2). The casing accommodates, arranged in series, a pneumatic separating duct (6) having a spreader (7) of loose material mounted therein, and a rotor (8) comprising a screen drum (9) having at the top portion thereof a distributor (81) of loose material. Screen cleaners (10,11) are provided outside of the drum (9) and directly engage it. A drive (4) of the screen drum is secured to the frame and imparts to the drum simultaneously rotary and oscillatory motions. The or each unit (1) communicates with an aspiration chamber (3). <IMAGE>

Description

SPECIFICATION Machine for cleaning and/or sorting loose materials i The present invention relates to separating machines, and more particularly, to machines for cleaning and/or sorting loose materials.

The present invention may be widely used for separating various loose materials in the chemical, mining and ore processing and food industries, and in particular, it may be very widely used in the agricultural production for cleaning and/or sorting grain and seed.

According to the invention, a machine for cleaning and/or sorting loose materials, comprising at least one cleaning and/or sorting unit, a hollow casing of said unit secured to a frame, said casing accommodating arranged in a sequence a pneumatic separating duct provided with a spreader for loose material mounted therein, a rotor comprising a screen drum secured thereto, a distributor being provided at the top portion of said drum, screen cleaners installed outside said drum and directly engaging it, a drive secured to the frame and imparting to the drum simultaneously rotary and oscillatory motions, each of said units communicating with an aspiration chamber, said screen drum being of composite design and consisting of a plurality of series-arranged sections and each of said sections comprising a screen in the form of a body of revolution, said screen being secured to support rings, and all sections being interconnected by means of equally spaced tierods extending through said support rings, said screen cleaners being installed diametrically opposite to one another with respect to the axis of rotation of said drum.

With this construction of the machine the efficiency of separation of loose material and the degree of modularization of the machines with different throughput capacity and application are simultaneously improved.

The screen is preferably made composite consisting of several parts joined along the generatrix.

This construction of the screen materially simplifies its replacement in the machine.

Joint portions of component parts of the screen are preferably incorporated in hollow straps, the walls of the hollow straps functioning as reinforcement ribs of the screen.

This facility ensures a desired sealing of the joint portions of the screen with simultaneous improvement of their radial rigidity.

Screen cleaners having smooth and bristly surface are preferably used in combination.

This provides for considerably more efficient cleaning of screen meshes from different particles of the material being separated.

The mesh cleaners are preferably made in the form of a body of revolution having a shaft supported by an arm, one end of the arm being pivotally connected to the casing of the unit and the other end to a shock absorber, and the cleaners are preferably biased against the outer surface of the screen drum by means of a spring.

This provides for a substantial improvement of stability of biasing of the cleaner against the screen, thereby intensifying the cleaning of meshes.

The shock absorber may comprise a friction couple having one member comprising a cylinder movably connected to the casing of the unit, and the other member comprising a curved plate rigidly secured to the second end of the arm, the convex side of the curved plate engaging the cylinder and the center of curvature of the plate surface coinciding with the pivotal joint center.

This simplifies the structure of the shock absorber and prolongs its service life.

The distributor may comprise a truncated cone with its greater base up.

This facility provides for a more uniform feeding of the material being separated to the screen surface.

The screen drum is preferably internally provided with longitudinal ribs comprising plates arranged around the distributor.

This facility eliminates tangential sliding of the material being separated over the screen surface and provides for more uniform distribution of the material over the perimeter of the screen.

The invention will now be described with reference to specific embodiments illustrated in the accompanying drawings, in which: Figure 1 is a diagrammatic view of a machine for cleaning and/or sorting loose materials according to the invention; Figure 2 is a longitudinal section of a rotor of a cleaning and/or sorting unit of the machine for cleaning and/or sorting loose materials according to the invention; Figure 3 is a transverse section of a cleaning and/or sorting unit of the machine for cleaning and/pr sorting loose materials according to the invention; Figure 4 is a sectional view of a pivotal joint of suspension of a screen drum to the rotor of the cleaning and/or sorting unit according to the invention; Figure 5 is a diagrammatic view of a screen mesh cleaner showing its fastening to the casing of a cleaning and/or sorting unit according to the invention.

A machine for cleaning ana/or sorting loose materials comprises e.g. two cleaning and/or sorting units 1 (Fig. 1) supported on a common frame 2 and communicating with an aspiration chamber 3. The frame 2 supports drives 4 of the units 1. The machine according to the invention may have also a single unit 1 as will be described below.

Each cleaning and/or sorting unit 1 has a hollow casing 5 installed on the frame 2. The top portion of the casing 5 accommodates an annular separating air duct 6 and a spreader 7 in the form of a truncated cone designed for feeding loose material into the annular duct 6.

A rotor 8 is arranged under the separating duct 6 (Figs. 2, 3) and has a screen drum 9.

Cleaners 10 and 11 of the screen drum 9 are installed on the casing 5 outside of the screen drum 9 and directly engage it (Figs. 1, 3).

Mounted over the casing 5 (Fig. 1) is a pipe 1 2 for feeding loose material to the spreader 7. The walls of the casing 5 have openings 1 3 for admitting air to the duct 6, and there are provided outlet passages 14, 15, 16, 1 7 and hatches 1 8. The casing 5 has an outlet 1 9 communicating with the aspiration chamber 3. The outlet passages 14 and 1 5 of each unit are interconnected by manifolds 20 and 21. The aspiration chamber 3 has inlet passages 22 with valves 23 and an outlet passage 24 with a valve 25, as well as a passage 26.

The rotor 8 (Fig. 1) is journalled in the casing 5 by means of bearings 27 and 28.

The bearing 27 is connected to the casing 5 by means of a cone 29 which is designed for feeding loose material to the rotor 8. The rotor 8 (Figs. 1, 2) has an upper shaft 30 which is rigidly secured to a plate 31 and a hollow lower shaft 32 rigidly secured to a plate 33. The plates 31 and 33 are rigidly interconnected by means of three struts 34.

The rotor 8 (Figs. 1, 2, 3) supports the screen drum 9 by means of suspensions 35 having pivotal joints 36. The suspensions 35 are arranged in triads in the upper and lower portions of the screen drum and ensure the transmission of rotary motion to the screen drum 9 while enabling vertical reciprocatory (oscillatory) motion of the drum 9.

The screen drum 9 is of composite design (Figs. 1, 2, 3) and consists e.g. of three series-arranged sections of which there are two identical sections 37 and a section 38, each section comprising a screen 39 in the form of a body of revolution, such as cylinder.

The screen 39 (Fig. 2) is preferably secured to support rings 40 and 41 in the section 38 and support rings 41 in the section 37. The support ring 41 (Fig. 3) may be made e.g. of a strong and lightweight material and comprises two concentrically arranged rims 42 and 43 interconnected by ribs 44. The inner rim 43 is provided with three equally spaced through holes 45 (Figs. 2, 3). The ring 40 (Fig. 2) may be made of the same material and has equally spaced holes 46 similarly to the ring 41. Hollow spacer struts 47 are provided between the rings 40 and 41 (Fig.

2) of the section 38 and between the rings 41 of the section 37, which are arranged opposite to the holes 46 and 45, respectively. The pivotal joints 36 of the suspensions 35 are arranged between the sections 37 and 38 opposite to the holes 45 of the rings 41, and a traverse (Figs. 1, 2, 3) is provided between the sections 37 in such a manner that holes 49 thereof (Fig. 2) should be in registry with the holes 45 of the support rings 41. Thepivot joints 36 of the suspensions 35 are also provided in the lower portion of the screen drum 9 opposite to the holes 45 of the rings 41. The sections 37 and 38, as well as the pivotal joints 36 and traverse 48 are tied up by means of equally spaced tierods 50 extending through the holes 46 of the ring 40, holes 45 of the rings 41, pivotal joints 36 and holes 49 of the traverse 48.

With such construction of the screen drum 9 screen drums may be made with different number of screens in machines for cleaning and/or sorting loose material having different throughput capacity and application using modularized sections 37 and 38. This provides for high degree of structural modularization of the machines thus reducing the manufacturing and operation cost.

The suspensions 35 (Figs 1, 2, 3, 4) comprise a rod having rings 51 at both ends (Fig.

4). The rings receive on either side sleeves 52 of an elastic wear resistant material, such as a rubber or a polyurethane elastomer. Steel sleeves 53 are mounted in the sleeves 52, the tierod 50 extending through the steel sleeve at one end of the suspension 35 (Fig. 2) and a strut 54 rigidly connected to the rotor 8 extending through the steel sleeves at the other end. This arrangement of the suspensions 35 ensures their high reliability in operation, while enabling desired motions of the screen drum 9.

To the rotor 8 (Fig. 1) are rigidly secured vanes 55 and 56 and to the screen drum 9 are rigidly secured vanes 57 and 58 (Figs. 1, 2). The vanes are designed for discharging fractions of the material being separated outside the unit 1 (Fig. 1). Between the rings 41 (Fig. 2) in the joint between the sections 37 and 38 are provided seals 59 made of an elastic material, such as rubber. The screen 39 (Figs. 2, 3) is of composite design split along its generatrix "A" (Fig. 2) e.g. into two identical parts I and II (Fig. 3). This design of the screen 39 materially simplifies the replace ment of the screen in the screen drum 9 (Figs. 1, 2, 3). The screen 39 of the machine according to the invention may be made consisting of a larger number of parts, such as 3 or 4 parts depending on the diameter of the screen 39.

In each section 37 and 38 (Fig. 2) are provided hollow straps 60 (Figs. 2, 3) rigidly secured to the rings 40 and 41. The number of the straps 60 should be equal to the number of the component parts of the screen 39, e.g. I and II. The joint portions 61 (Fig.

3) of the parts I and il of the screens 39 should be received between walls 601 and 60" of the hollow straps 60. The walls 60' and 60" simultaneously function as reinforce ment ribs of the parts I and Il of the screen 39 for improving the radial rigidity. This facil ity ensures sealing of the parts I and II of the screen 39 at the joints along the generatrix "A" (Fig. 2) and also materially prolongs its service life by improving the radial rigidity.

For more reliable retaining of the parts I and II (Fig. 3) of the screen 39, collars 62 are installed on the support rings 40 and 41 (Fig.

2) and in the hollow straps 60 (Figs. 2,3).

For cleaning each screen 39 (Figs. 2, 3), there are provided, in combination, e.g. two cleaners 10 and 11 (Figs. 1, 3) installed diametrically opposite to one another with respect to an axis of rotation 63 (Figs. 1, 2) of the screen drum 9. One cleaner, e.g. the cleaner 1 0 (Figs. 1, 3) has a smooth surface, and the other cleaner 11 has a bristly surface.

The number of the cleaners of the types of the cleaners 10 and 11 may be more than two, such as four, depending on the diameter of the screen 39. The cleaners 10 and 11 comprise bodies of revolution having a shaft 64 (Fig. 5) journalled by means of a bearing 65 on an arm 66. One end 66" of the arm 66 is connected by means of a pivotal joint and a column 68 to a plate 69 rigidly secured to the casing 5. The second end 66' of the arm 66 is coupled to a shock absorber 70. The shock absorber 70 is designed for damping induced oscillations of the cleaners 10 and 11 developed during rotation of the screen drum 9 (Figs. 1, 2, 3). The shock absorber 70 (Fig. 5) comprises e.g. a frictional shock absorber consisting of two members 71 and 72. The member 71 is preferably in the form of a cylinder and is connected by means of a strut 73 and a pivotal joint 74 to the plate 69.The member 71 may be made of a material such as textolite polyamide, fluoroplast and the like.

The member 72 comprises a curved plate of a hard wear resistant material and is rigidly secured to the end 66' of the arm 66. The convex side 75 of the member 72 engages the member 71, and the center of curvature "0' " (radius of curvature "R") of the surface 75 should coincide with the center "0" of the pivotal joint 67. The surface of the convex side 75 of the member 72 is smooth.

The members 71 and 72 are urged against one another by means of a spring 76 which also biases the cleaners 10 and 11 against the surface of the screens 39 (Figs 2, 3, 5) of the screen drum 9 (Figs. 1, 2, 3) through a strut 77 rigidly secured to the arm 66. The provision of frictional shock absorber 70 (Fig.

5) ensures simplicity of its structure and high operation reliability. The shock absorber in the machine according to the invention may also be of hydraulic or magnetoelectric type depending on abrasive or magnetic properties of the loose material being separated.

The cleaners 10 (Figs. 1, 3, 5) with smooth surface may comprise e.g. plates 78 (Fig. 5) installed on the shaft 64. The plates are preferably made of a wear resistant material.

The cleaners 11 with bristly surface (Figs. 1, 3) may also comprise plates 79 (Fig. 3) having elastic bristle 80 secured thereto. The bristle 80 may be made e.g. of wear resistant synthetic materials.

A distributor 81 (Figs. 1, 2) is rigidly connected to the shaft 30 of the rotor 8 and comprises a truncated cone having its greater base 82 turned up. The screen drum 9 is internally provided with longitudinally extending ribs 83 (Figs. 1, 2) comprising plates rigidly secured e.g. to the ring 40 around the distributor 81. This construction of the distributor 81 and the provision of the ribs 83 ensure uniform feeding and distribution of the material being separated in the screen drum 9 (Figs. 1, 2, 3).

To impart rotary motion to the rotor 8 of each unit 1 (Fig. 1), the frame 2 has an electric motor 84 with a pulley 85 which is coupled by means of a belt transmission 86 to a pulley 87 rigidly secured to the rotor 8.

To impart to the screen drum 9 of each rotor 8 (Fig. 1) oscillatory motion along the axis 63, the frame 2 has a vibrator (oscillator 88 having a crankshaft 89 connected to an electric motor 90. A crank 91 of the crankshaft 89 is movably coupled to a rod 92 (Figs. 1, 2) which is coupled to the traverse 48 by means of a bearing 93. To relieve the crankshaft 89 (Fig. 1) from the gravity of the screen drum 9, the traverse 48 is coupled by means of the spring 94 to the shaft 30 of the rotor 8 (Figs. 1, 2). This facility ensures the transmission of the gravity of the screen drum 9 to the rotor 8.

In case it is necessary to reduce rated capacity of the machine according to the invention, only one unit 1 (Fig. 1) may be installed. In such case the number of drives 4 is reduced respectively, and the dimensions of the frame 2 are reduced, while the aspiration chamber 3 is made with a smaller number of the passages 22 and valves 23. The manifolds 20 and 21 are dispensed with.

The machine for cleaning and/or sorting loose materials according to the invention functions in the following manner. When the electric motor 84 is switched on (Fig. 1), the rotor 8 is caused to rotate by means of the belt transmission 86. At the same time, rotary motion is imparted by the rotor 8 through the suspensions 35 (Figs. 1, 2, 3) to the screen drum 9. The cleaners 10 and 11 (Figs. 1, 3) urged against the screens 39 (Figs. 2, 3) of the screen drum 9 (Figs. 1, 2) under the action of friction forces also rotate. When the electric motor 90 is switched on (Fig. 1), the crankshaft 89 of the vibrator 88 also starts rotating so that the rod 92 imparts oscillatory (reciprocatory) motion along the axis 63 to the screen drum 9 through the traverse 48 (Figs.

1,2).

Loose material to be separated is fed to the pipe 12 (Fig. 1) wherefrom it is admitted to the spreader 7 rotating together with the rotor 8.

At the same time, a blower which can be installed outside the machine creates an air flow through the openings 13, anular duct 6, outlet 19, passage 22, aspiration chamber 3, passage 26 and further along an auxiliary pneumatic line to the blower.

The material being separated which is distributed by the spreader 7 in the annular duct 6 is blown through by the air flow which separates lightweight particles from the material being separated and conveys them to the aspiration chamber wherefrom they are discharged into the passage 24 and are then fed through the valve 25 to the manifold 20.

After the air treatment, the material being separated is fed by the cone 29 to the distributor 81 which rotates together with the rotor 8. Owing to the provision of the distributor 81 constructed according to the invention the loose material slides over its inner surface radially and tangentially whereby the material is uniformly distributed over the surface of the ring 40 (Fig. 2) provided with the ribs 83 (Figs. 1, 2). The ribs 83 entrain equal batches of the loose material and impart thereto a rotary speed which is equal to the rotary speed of the screen drum 9. At the same time the ribs 83 prevent said batches of the material from sliding in the tangential direction. All these factors ensure uniform distribution of the material being separated along the perimeter of the screens 39 (Figs. 2, 3), which is very important to provide for highly efficient operation of the screens 39.This improves throughout capacity and quality of operation of the screens 39.

When the material being separated rotates together with the screen drum 9 (Fig. 2) a centrifugal inertia force develops which urges the material against the inner surface of each screen 39, and the oscillatory motion of the screens together with the screen drum 9 provides an additional inertia force whjch cooperates with the gravity of particles to ensure the downward linear movement of the material being separated along the screen surface.

These factors in combination ensure an intense screening e.g. of the finest particles by means of the upper screen 39 (Fig. 2), of coarser particles by means of the intermediate screen 39 and coarse particles by means of the lower screen 39. Each fraction of the loose material is discharged by the vanes 58, 57, 56, respectively (Figs. 1, 2), into the outlet passages 14, 15, 1 6 (Fig. 1).

The coarsest particles of the material being separated are obtained from the lower screen 39 (Fig. 1) and are discharged by the vanes 55 into the outlet passage 1 7. Thus the starting mixture of loose materials is divided into a desired number of fractions which is an important advantage of the machine according to the invention compared to the prior art machines of the type.

The hollow straps 60 (Figs. 2, 3) prevent the material being separated from being spilt in the joint portions 61 (Fig. 3) of the parts I and II of the screens 39 thus precluding contamination of the fractions of the material and improving operation of the machine according to the invention.

When the loose material is screened through the screens 39 (Figs. 2, 3) their meshes are intensely clogged with the particles of loose material. These particles are forced out of the meshes by means of the cleaners 10 and 11 (Figs. 1 3). The installation of the cleaners 10 and 11 diametrically opposite to one another with respect to the axis 63 (Figs. 1, 2) of rotation of the screen drum 9 (Figs. 1, 2, 3) according to the invention ensures more intense cleaning of meshes of the screens 39 (Figs. 2, 3) compared with the provision of identical cleaners 10 and 11 installed on one side of the screen drum in conventional machines. This also contributes to a material improvement of efficiency of operation of the screens 39.

The use of the cleaners 10 with smooth surface and cleaners 11 with bristly surface (Figs. 1,3) in the machine according to the invention also improves the cleaning of meshes of the screens 39 (Figs. 2, 3) owing to the fact that the smooth cleaners 10 exhibit a desired rigidity so as to more efficiently force out of the meshes strongly retained particles which mainly protrude over the outer surface of the screens 39. The cleaners 11 (Figs. 1,3) having the elastic bristle on their surface are more effective in forcing out the particles which seat deep in the meshes. It is the combined use of the cleaners 10 and 11 that ensures much more efficient cleaning of the meshes compared to their separate use, and this combination additionally improves the throughput capacity and quality of operation of the machine according to the invention.

When the cleaners 10 and 11 (Fig. 3) roll over the surface of the screens 39 they are spaced apart from the screens at regular intervals as a result of the action of various factors on the cleaners 10 and 11, including the action of particles of the material being separated protruding from the meshes. This movement of the cleaners 10 and 11 impairs the intensity of cleaning of the meshes. In order to substantially reduce the negative result of this phenomenon, the cleaners 10 and 11 are coupled to the frictional shock absorber 70 (Fig. 5). When the cleaner 10 or 11 (Figs. 3, 5) is spaced apart from the screen 39, the member 72 (Fig. 5) of the shock absorber 70 is displaced relative to the member 71, and a major part of the kinetic energy of the cleaner 10 or 11 is spent for work by friction forces at the contact of the members 71 and 72.

The provision of the member 72 in the form of a curved plate having a curvature center "0"' coinciding with the center "0" of the pivotal joint 67, and the provision of the member 71 in the form of the cylinder ensure smooth displacement (sliding of the element over the convex surface 75 of the member 72 (without scoring and jamming). The reliability of the shock absorber 70 in operation and efficiency of cleaning of the screens 39 by the cleaners 10 and 11 (Figs. 1, 3) are thus substantially improved.

In the machines for cleaning and/or sorting loose materials of this type it is very important to ensure an efficient cleaning of screens which should be readily removable and modularized. It is the provision of the screen drum 9 of a composite design (Figs. 1, 2) consisting of a plurality of sections 37 and 38, the provision of the screens 39 of composite design consisting of e.g. two parts I and II joined along the generatrix and installation of the cleaners 10 and 11 of the screens diametrically opposite to one another according to the invention, that give to the machine according to the invention its main advantage which resides in substantially improved efficiency of operation and high degree of modularization. Moreover, the use of smooth and bristly cleaners 10 and 11 in combination and coupling of the cleaners 10 and 11 to the frictional shock absorber 70 add to the efficiency of the machine owing to more intense cleaning of the screen meshes. Apart from that, the provision of uniform feeding of the material being separated to the screens 39 by providing the distributor 81 and the ribs 83, according to the invention, materially improves the efficiency of the machine operation.

Claims (9)

1. A machine for cleaning and/or sorting loose materials, comprising at least one cleaning and/or sorting unit, a hollow casing of said unit secured to a frame, said casing accommodating arranged in a sequence a pneumatic separating duct provided with a spreader for loose material mounted therein, a rotor comprising a screen drum secured thereto, a distributor being provided at the top portion of said drum, screen cleaners installed outside of said drum and directly engaging it, a drive secured to the frame and imparting to the drum simultaneously rotary and oscillatory motions, each of said units communicating with an aspiration chamber, said screen drum being of composite design and consisting of a plurality of series-arranged sections and each of said sections comprising a screen in the form of a body of revolution, said screen being secured to support rings, and all sections being interconnected by means of equally spaced tierods extending through said support rings, said screen cleaners being installed diametrically opposite to one another with respect to the axis of rotation of said drum.

2. A machine as claimed in Claim 1, wherein said screen is of composite design and consists of a plurality of component parts joined along the generatrix.

3. A machine as claimed in Claim 2, wherein the joint portions of the component parts of said screen are incorporated in hollow straps, the walls of said hollow straps functioning as reinforcement ribs of said screen.

4. A machine as claimed in Claim 1, wherein said cleaners of said screens comprise smooth cleaners and bristly cleaners used in combination.

5. A machine as claimed in Claims 1, 4, wherein each of said cleaners comprises a body of revolution having a shaft movably supported by an arm which has one end coupled by means of a pivotal joint to said casing of said unit, the second end of the arm being connected to a shock absorber, said cleaners being biased against the outer surface of said screen drum by means of a spring.

6. A machine as claimed in Claim 5, wherein said shock absorber comprises a frictional couple having one member in the form of a cylinder which is movably coupled to said casing, the other member comprising a curved plate which is rigidly secured to the second end of said arm, the convex side of said curved plate engaging said cylinder and the center of curvature of said convex side of said curved plate coinciding with the center of said pivotal joint.

7. A machine as claimed in Claims 1, 2, 3, wherein said screen drum is internally provided with longitudinally extending ribs comprising plates arranged around said distributor.

8. A machine as claimed in Claim 7, wherein said distributor of loose material comprises a truncated cone with its greater base up.

9. A machine for cleaning and/or sorting loose materials substantially as hereinabove described with reference to, and as shown in the accompanying drawings.