EP0392455B1 - Separator - Google Patents

Abstract

In a purification machine for granular material, having a screening space (12) into which an input shaft (6), arranged above a grate (5) through which an airstream (2) flows, leads and which is adjacent to an expansion space (17) and having at least one ventilator (24) which generates the airstream and is arranged upstream of an associated air purifying device connected to the expansion space (17), a simple and compact design and a low energy requirement and good degree of purification is achieved in that the air purification device has at least one centrifugal force separator (21) extending over the width of the assigned grate (5), arranged with its axis parallel to the grate and provided with a suction pipe (29), which is surrounded by a curved channel (30) running out of the expansion space (17), and having a circumference-side deflection grid (31,32), the suction pipe being connected to the ventilator (24) which is built onto the side wall of the separating housing (22) and is connected to a distributor box (26), which is arranged in the region of the machine end side adjacent to the grid (5), through a supply channel (25) extending in the region of the adjacent machine side wall, said distributor box (26) being open towards the screening space (12) and the gaps of the grate (5) facing said distributor box. <IMAGE>

Description

The invention relates to a cleaning machine for granular items to be cleaned, in particular a grain cleaning machine or the like, with at least one viewing space, into which an inlet shaft arranged above a grate through which an air stream flows and into which an expansion space adjoins and with at least one opening opens Airflow generating fan, which is arranged downstream of an associated air cleaning device connected to the expansion space.

An arrangement of this type is known from DE-C-2650617. This known arrangement works for the most part with circulating air, which is desirable for emission reasons, but has proven to be not compact and energy-saving enough. In this known arrangement, the air cleaning device and the fan are arranged separately from the cleaning machine, longer pipe sections being provided between the individual units, which are also required here in order to achieve a lamination of the flow. However, the external arrangement of the air cleaning device and the fan obviously results in a high construction effort and leads to a very bulky construction. In addition, this results in high line losses, which lead to high energy requirements. This disadvantage is exacerbated by the fact that the air cleaning device should practically contain a cyclone which, on the one hand, results in a high energy requirement and, on the other hand, requires long pipelines. In addition, an arrangement of the known type counteracts a uniform distribution of the air throughput over the entire width of the machine. This disadvantage is exacerbated by the fact that the grate is arranged essentially horizontally and flows through from bottom to top, which complicates the uniform flow distribution and also adversely affects the energy requirement.

Proceeding from this, it is therefore the object of the present invention to improve a device of the type mentioned at the beginning with simple and inexpensive means in such a way that not only a compact design but also Favorable energy consumption can also be achieved and at the same time a high cleaning effect is guaranteed.

This object is achieved in that the air cleaning device has at least one centrifugal separator which extends across the width of the associated grate and is arranged with a grate-parallel axis and which is provided with a suction pipe which has a circumferential deflecting grille and is provided with a suction duct which runs out of the expansion space Fan is connected, which is attached to the side wall of the separator housing and is connected through a supply duct running in the area of a machine side wall to a distribution box which is arranged in the area of the machine front side adjacent to the grate and which is open to the viewing space and to which the gaps in the grate face.

The technical progress that can be achieved with these measures can be seen in particular in avoiding the disadvantages of the known arrangements. The centrifugal separator, which is equipped with a deflection grille and immersion tube, not only ensures excellent separation quality with low energy consumption, but can also be easily integrated into the machine structure in an advantageous manner due to its horizontal arrangement so that a simple, compact design is achieved. The horizontal suction pipe also advantageously enables the fan to be arranged on the side and, accordingly, the supply duct to be moved to the side, which results in an inexpensive, low-loss arrangement Flow guidance leads. This is exacerbated by the action on the visible space by means of a distribution chamber arranged on the end face and by inclination of the grate. Nevertheless, a uniform distribution of the air quantity over the entire grate width is ensured in a simple manner, without any appreciable resistance being required, which also has a favorable effect on the cleaning quality that can be achieved and the energy requirement. As a result of the inclination of the grate there is only a slight deflection of the air and it is nevertheless ensured that the flow of the material to be cleaned is passed through approximately vertically, which results in an excellent sighting. Another advantage of the measures according to the invention can be seen in the fact that the feed material can generally be fed to the grate simply by gravity. There is also a shortening of the grate, which leads to an increase in the space available for the actual visual space.

In an advantageous development of the superordinate measures, the plane of the grate can be inclined at an angle of 45 ° to the horizontal. This measure results in particularly favorable flow conditions.

A further advantageous measure can consist in the fact that the front-side distribution box has a clear cross section that continuously decreases over its width and is provided with guide vanes arranged in its interior. These measures lead to a particularly even flow distribution across the entire grate width without any significant resistance.

A further advantageous embodiment can consist in that a preferably pivotable slide connects to the input shaft. This makes it possible to regulate the path of the feed material and thus to carry out a classification. For the same purpose, the upper region of the wall opposite the input shaft between the viewing space and the expansion space can advantageously also be designed as a slide that can be set up and put down.

A further, very particularly preferred measure can consist in that the suction pipe and / or the curved channel are divided by radial diaphragms into several sections arranged side by side. This subdivision in the axial direction advantageously has the effect that the flow in the arc channel cannot or not significantly be deflected in the axial direction even if the fan is spaced from the separator housing which contains the arc channel and is penetrated by the suction pipe is set, which enables a compact, inexpensive structure. At the same time, the lack of axial flow deflection results in high centrifugal forces, which has an advantageous effect on the achievable separation quality. In addition, the subdivision of the deflection grid according to the invention leads to resistance conditions which cause a comparatively uniform train over the entire length of the suction pipe and thus a comparatively uniform distribution of the mass flow over the entire length of the suction pipe, which also has a positive effect on the separation quality that can be achieved. This applies in an advantageous manner even if the deflection grating extends over the entire circumference of the suction tube, so that there is no need for meshless jacket sections, which not only enables simple construction of the suction tube, but also advantageously results from the axial division of the The resulting increase in the resistance of the deflection grid is largely compensated for and accordingly overall leads to comparatively low losses and thus to a comparatively low energy requirement.

In a further development of the superordinate measures, the radially outer wall of the arch channel can be provided with a separation outlet which is continuous over the entire width and to which a suction chamber connects, which is followed by a post-cleaning device. This measure ensures a reliable discharge of the impurities separated by the centrifugal separator from the air to be returned as recirculated air, together with a comparatively low partial air flow.

This can therefore be brought to a high degree of purity in a simple and inexpensive manner by means of filters etc., so that it can be released into the environment without hesitation. The resulting air loss within the machine is supplemented by fresh air drawn in in the area of the distributor box. The circulating air is accordingly continuously mixed with fresh air, so that the loading of the process air with non-separable fine dust advantageously remains within tolerable limits.

A peeling lip can advantageously be provided in the area of the deposition outlet. This ensures reliable removal of the contaminants.

Another expedient measure can consist in that the edge region of the deposition outlet opposite the peeling lip is designed as a baffle bar projecting approximately perpendicularly to the peeling lip into the chamber. This measure prevents solids, which impinge on the chamber wall opposite the deposition outlet, from rebounding into the arch channel.

Further expedient further training and advantageous further training of the superordinate measures result from the remaining subclaims.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawing.

• Figur 1 einen schematischen Querschnitt durch den Ventus einer Getreidereinigungsmaschine,
• Figur 2 einen schematischen Längsschnitt durch die Anordnung gemäß Figur 1,
• Figur 3 einen vergrößerten Querschnitt durch den Fliehkraftabscheider der Anordnung gemäß Figur 1,
• Figur 4 eine Explosionsdarstellung des Fliehkraftabscheiders und
• Figur 5 eine Alternative zu Figur 3 im Bereich des Abscheidungsauslasses.

The drawing shows:

• FIG. 1 shows a schematic cross section through the ventus of a grain cleaning machine,
• FIG. 2 shows a schematic longitudinal section through the arrangement according to FIG. 1,
• FIG. 3 shows an enlarged cross section through the centrifugal separator of the arrangement according to FIG. 1,
• Figure 4 is an exploded view of the centrifugal separator and
• Figure 5 shows an alternative to Figure 3 in the area of the deposition outlet.

The Ventus on which Fig. 1 is based, which can be used, for example, to clean grain before storage, is based in a manner known per se on the wind sifting principle, ie. H. A feed stream 1 is penetrated by an air stream 2, the feed stream being divided into two fractions 3, 4, as indicated by arrows in FIG. 1. The fraction 3 containing the heavier parts in the form of usable grain etc. falls through downward and can then be further processed, e.g. B. sieved, classified, etc. The fraction 4 containing the lighter parts in the form of the impurities, the unusable grains etc. is entrained by the air flow.

The ventus shown has, as can also be seen in FIG. 1, a feed shaft 6 which is arranged above a grate 5 and to which the material to be cleaned is applied. The grate 5 is formed by spaced apart, aerodynamically profiled slats which extend over the entire machine width, or here over one machine half of the machine, which is constructed in mirror image with respect to a central longitudinal plane. The exit of the feed chute 6 is adjustable by means of a pivotable flap 7. In the illustrated embodiment, a feed roller 8 is arranged in the area of the exit of the feed chute. The feed chute 6 is followed by a slide 9, also formed by a pivotable flap, through which the feed stream 1 is passed over the grate 5. The grate plane is strongly inclined to the horizontal, here at an angle of about 45 °, so that the air flow 2 between the lamellas resulting rust gaps 10 can flow with strong horizontal component.

The feed chute 6 opens into a viewing space 12 containing the grate 5, here delimited at the top by a flow guide plate 11, in which the first and second fractions 3, 4 are separated. The bottom of the viewing space 12 is funnel-shaped, i. H. with V-shaped inclined flanks 13 and has a downwardly open window 14 through which the first fraction 3 is discharged downwards. The second fraction 4 is discharged via a window 15 diagonally opposite the grate 5 and provided in the region of the wall of the viewing space 12 opposite the feed shaft 6. This is limited by a slide 16 which can be pushed on and pushed off in the region of the assigned wall and on the position of which the respective size of the fractions 3, 4 depends.

The viewing space 12 is adjoined by an expansion space 17 accessible via the window 15, the funnel-shaped base of which is provided with a discharge lock 18. In the expansion space 17, the second fraction 4 is separated into two partial streams 4a, 4b, as is further indicated in FIG. 1 by arrows. The first partial stream 4a is formed by the heavier particles in the form of light grain or broken grains or the like. The partial stream 4a is discharged via the discharge lock 18. The second part stream 4b is formed by the light parts in the form of chaff, stalks and the like. These are entrained by the air, which exits through a window 19 opposite the window 15 sionsraum 17 exits.

At the window 19, which, in contrast to the window 15, is not adjustable, the inlet connection 20 is connected by a centrifugal separator 21, which has a horizontal axis and extends over the same width as the grate 5 and accordingly as the viewing space 12 and the expansion space 17 from which the impurities remaining in the air stream are separated. As can best be seen from FIG. 2, a fan 24, which can be driven by a motor 23 and which moves the air flow passing through the valve, is laterally attached to the housing 22 of the centrifugal force separator 21. The air sucked in by the fan 24 and cleaned in the centrifugal separator 21 is returned to the assigned grate 5. For this purpose, a supply shaft 25, which runs in the area of the ventilator side wall on the ventilator side, flows to the pressure connection of the ventilator and leads to a distribution box 26 which is arranged in the area of the ventilator end side and extends over the same width as the assigned grate 5. In order to achieve the most uniform possible air distribution over the entire grate width, this has a cross section that decreases across the machine width. In the illustrated embodiment, additional baffles 27 are provided in the area of the distributor box 26 in order to achieve a particularly uniform air distribution, as can further be seen in FIG. As a result of the return of cleaned air, ie the use of recirculated air, there is only a small requirement for fresh air. In the exemplary embodiment shown, the supply shaft 25 is provided with a shut-off blind 28 which throttles of the circulating air flow.

The centrifugal separator 21 contains a suction pipe 29 which is directly attached to the suction nozzle of the fan 24, which is designed as a radial fan, and which is also arranged with a horizontal axis and which is inserted into an approximately circular cross-section of the working space of the housing 22, the diameter of which is larger than the suction pipe diameter is, so that there is an arc duct 30 which encompasses this and into which the inlet connection 20 adjoining the window 19 enters, as can best be seen from FIG. The horizontal axes of the suction pipe 29 and the circular cross section of the working space receiving the suction pipe 29 are offset from one another in such a way that a clear cross-section of the arc channel 30, which decreases in the flow direction from the inflow connection piece 20, results with its end having the smallest cross-section in its at the Inflow connector 20 adjoining the beginning. As best seen in FIGS. 2 and 3, the suction pipe 29 acting as an immersion pipe is designed as a grid pipe, which is provided on its entire circumference with axially parallel fins 31 which form a deflection grid and are circumferentially spaced from one another to form throughflow slots 32. The air flowing through the curved channel 30 on a curved path is, as indicated by the arrows 33 in FIG. 3, subjected to an even sharper curvature when flowing out through the slots 32, which further increases the effective centrifugal forces indicated by the arrow 34. These cause the solids still entrained in the air, in the form of the entrained impurities, to move radially Wander outside so that the air sucked in through the suction pipe 29 has the desired degree of purity.

As can best be seen from FIG. 4, the suction pipe 29 is designed as an insertion part that can be inserted into the associated work space. For this purpose, the walls of the housing 22 extending perpendicular to the axis are provided with corresponding recesses 35. The suction tube 29, which is designed as an insertion part, is provided with flanges 36 in the region of its ends and can thus be flanged to the housing end walls. The suction pipe 29 on which the exemplary embodiment shown is based, as can also be seen in FIG. 4, consists of impellers of radial fans flanged to one another with vanes curved backwards. As a result of the flow direction present here, which runs from radially outside to radially inside, this results in a curvature of the fins 31 forming the deflection grille, which is directed forward in the flow direction further shows, radial diaphragms 37 through which the peripheral deflection grating is divided into several sections 38 in the axial direction. The result of this subdivision is that the flow going inward according to arrow 33 takes place essentially in the radial direction and without any significant axial component, which ensures a uniform distribution over the entire length of the intake manifold.

In the exemplary embodiment shown, the curved channel 30, as can best be seen in FIGS. 2 and 4, is formed by intermediate walls 39 arranged between its end walls also divided into several sections 30a. The sections 30a of the curved channel are wider than the sections 38 of the suction pipe 29 surrounded by it, which can contribute to increasing the desired uniformity. As can best be seen from FIG. 2, the intermediate walls 39 have rounded leading edges 40, on which stalk pieces etc. are not kinked, but rather can slide over the stalk pieces etc. The intermediate walls 39 extend, as can best be seen from FIG. 3, from the inlet connection 20 to the area of a deposition outlet 42 provided in the area of the circumferential, radially outer wall 41 of the working space receiving the suction pipe 29, through which the radial centrifugal effect occurs due to the effective centrifugal forces material migrated outside is discharged in the form of impurities.

For this purpose, a peeling lip 43 is provided in the area of the separating outlet 42 and protrudes into the cross section of the curved channel 30, which peels off the radially outer flow layer loaded with the contaminants and introduces it via the separating outlet 42 into an adjoining, laterally extractable chamber 44. The chamber 44, which is also arranged with a horizontal axis and here has an approximately elliptical cross section, extends over the entire width of the centrifugal separator 21. The separation outlet 42 is located in the region of the narrow region of the end region of the arch channel 30, here in the region of the last quadrant of the arch channel 30th

The peeling lip 43 is provided with a rounded inflow flank for the same reason as the intermediate walls 29, as is further indicated in FIG. 3. The peeling lip 43, which is arranged in a stationary manner in the embodiment on which FIG. 3 is based, covers approximately the outer third of the clear cross-section of the arched channel 30. However, it would also be readily possible to design the peeling lip 43 as a pivotable flap, the degree of coverage being adjustable. Such an embodiment is indicated in Figure 1. The boundary of the deposition outlet 42 opposite the peeling lip 43 runs with its end region approximately perpendicular to the peeling lip 43 to the outside, i. H. into the chamber 44 and accordingly forms a baffle bar 45 which prevents solid particles impinging on the wall of the chamber 44 opposite the deposition outlet 42 from rebounding into the arched channel 30.

From the chamber 44 accessible via the separation outlet 42, as best shown in FIGS. 2 and 4, there is a lateral, tubular suction nozzle 46, which is connected to a post-cleaning device 47 indicated in FIG. 2, which can be attached laterally or placed on top, etc. .. The suction connection 46 leads below the pressure connection of the fan 24, which is designed as a radial fan and arranged parallel to the suction connection, with its axis, which enables a high degree of structural freedom. The post-cleaning device 47 consists of a fan part 48, which is preceded by a filter part 49 and a separating part 50, for example in the form of a cyclone separator, and which has a blow-out nozzle 51 opening into the surroundings is provided. The air blown out into the environment, from which the solids were previously separated or filtered out, is clean and therefore completely harmless to the environment. The resulting loss of circulating air as a result of the release of air into the environment is compensated for by the fact that fresh air can also be sucked in in the area of the grate 5 in addition to the circulating air, as indicated in FIG. 1 by the flow arrow 2a. This fresh air drawn in from below mixes with the circulating air, which keeps its load of fine dust low.

As shown by tests, the approximately elliptical cross section of the extractable chamber 44 on which FIGS. 1 to 4 are based results in a particularly reliable removal of the contaminants still present in the air. However, other cross-sectional shapes are also conceivable, as shown for example in FIG. 5. This design is based on a slotted tube 52 forming the chamber 44, the jacket flanks of which in the area of the slit are bent to form the separation outlet 42 and a peeling lip and baffle strip adjacent thereto in the radial direction. The tube 52 can be arranged stationary, peeling ratios similar to those in the embodiment according to FIG. 3 being achievable. However, it would also be conceivable to arrange the tube 52 so that it can rotate about its axis, as a result of which the jacket flanks delimiting the deposition outlet 42 can be moved back and forth to change the peeling conditions, as is indicated in FIG. 5 by dashed lines. It would of course also be conceivable, in addition, a pivotable peeling lip to provide. In any case, the end regions of the circumferential wall of the chamber 44 which are spaced apart from one another to form the deposition outlet 42 run into the circumferential wall 41 of the curved channel 30 which is interrupted to form the deposition outlet 42.

The Ventus on which FIGS. 1 and 2 are based can extend over the entire width of the associated cleaning machine. In the illustrated embodiment, as can best be seen from FIG. 2, two valves are provided which are arranged in a mirror-image arrangement and each cover one machine half. Each of these two venti is self-sufficient, i.e. H. provided with its own fan 24 and its own post-cleaning device 47.

Claims (10)

1. A cleaning machine for granular material, more particularly a cereal cleaning machine etc., comprising at least one air separation space (12), into which an input passage (6) opens, through which an air current (2) passes, and which is arranged over a grating (5), which air separation space (12) is adjoined by an expansion space (17), and at least one fan (24), producing the air current, connected with the outlet of an associated air cleaning device which is connected with the expansion space (17), characterized in that the air cleaning device comprises at least one centrifugal separator (21) which extends over the full width of the associated grating (5) and whose axis is parallel to the grating, such centrifugal separator being provided with a discharge tube (29) contained within an elbow duct (30) extending out of the expansion space (17) and such tube (29) having a circumferential deflecting grid (31 and 32), which discharge tube (29) is connected with the fan (24) which is joined to the side wall of the separator housing (22) and is connected with a distributor chest (26) by a supply duct (25) extending near the adjacent side wall of the machine, said chest (26) being adjacent to the machine side near the grating (5), being open towards the air separation space (12) and having the gaps of the grating (5) directed towards it.
2. The cleaning machine as claimed in claim 1, characterized in that guide vanes (27) are arranged adjacent to the distributor chest (26), which preferably has a clearance cross section continuously diminishing over its width.
3. The cleaning machine as claimed in either of the proceeding claims 1, characterized in that the supply duct (25) is provided with a shut of device (28).
4. The cleaning machine as claimed in any one of the proceeding claims, characterized in that a preferably pivoting chute (9) adjoins the input passage (6) and in that the plane of the grating (5) is inclined in relation to the horizontal by an angle of preferably approximately 45°.
5. The cleaning machine as claimed in any one of the proceeding claims, characterized in that between the air separation space (12) and the expansion space (17), preferably provided with a discharge air lock (18), the upper part of the wall opposite to the input passage (6) is designed in the form of a slide (16) able to be opened and closed and in that a lower part of the wall between the air separation space (12) and the expansion space (17) is designed in the form of a funnel side (13)
6. The cleaning machine as claimed in any one of the proceeding claims, characterized in that the elbow duct (30) has a generally tangentially entering input flow port (20) which is connected with an associated window (19) of the expansion space (17).
7. The cleaning machine as claimed in any one of the proceeding claims, characterized in that the housing (22) of the centrifugal separator (21) preferably has a working space, delimited by a radially outer, circumferentially extending wall (41), with a generally circular cross section, in which the discharge tube (29), whose circumferential deflecting grid preferably extends over the full periphery, is arranged eccentrically, which discharge tube is preferably like the elbow duct (30), subdivided into a plurality of adjacently arranged sections (38 and respectively 30a) by radial baffles (37 and respectively 39).
8. The cleaning machine as claimed in any one of the proceeding claims, characterized in that the radially outer wall (41) of the elbow duct (30) is provided with a waste material outlet (42) extending over the full width and which is adjoined by a chamber (44), able to be emptied by suction, which is followed by a subsequent cleaning device (47), a preferably adjustable stripping lip (43) being provided adjacent to the waste material outlet (42) and the edge part of the waste material outlet (42) opposite to the stripping lip (43) being designed in the form of a baffle bar (45) extending into the chamber (44) generally perpendicularly in relation to the stripping lip (43).
9. The cleaning machine as claimed in claim 8,
      characterized in that the chamber is able to be emptied by suction via a laterally leaving port (46), which extends through underneath the intake port of the laterally mounted fan (24).
10. The cleaning machine as claimed in any one of the proceeding claims 8 or 9, characterized in that the subsequent cleaning device (47) has a fan (48) discharging into the environment and which is or respectively are followed by a filter (49) and/or a waste removal device (50).

Images