SCREENING DEVICE

Description

[0001] The invention relates to a screening device for screening granules, in particular moist and / or dry granules, comprising a screen housing having a bottom, a lid and a side wall, an inlet opening for the granules arranged on the screen housing, an outlet opening for the screened granules arranged on the screen housing, a screen arranged in the screen housing and an inlet opening for transfer air arranged on the screen housing.

[0002] Screening devices for granules, particularly for screening processes downstream of a wet granulation process or a drying process in a fluidization apparatus, have long been state of the art. These known screens are filled through an inlet opening for the granules located on the cover of the screen and emptied after the screening process through an outlet opening located in the base of the screen after a suction shoe. The granules are transported from the inlet opening to the outlet opening, for example, via gravity feeding or pneumatic conveying.

[0003] EP 0 159 050 A1 discloses a device for separating grain into fractions of different densities. For this purpose, the device has two fluidized bed tables arranged one above the other, which are permeable to air and mounted for oscillation. The upper fluidized bed table is fed with the grain via an inlet, opposite which is an outlet for the light fraction. The lower fluidized bed table has an outlet for the heavy grain fraction, opposite which is an outlet for the heaviest grain fraction at the other end. To increase the separation quality, it is proposed that the upper fluidized bed table be divided into at least two consecutive areas of different perforation in the direction from the inlet towards the outlet for the light grain fraction. The perforation of the upper fluidized bed table is designed in such a way that the aforementioned grain fractions can only fall through in the area(s) following the first area.Between the fluidized bed tables and below the second area, a floor is arranged which extends across its width, with an outlet for a medium-heavy grain fraction at the end of the floor opposite the inlet.

[0004] CN 106 670 107 A discloses an impurity removal box for feeding raw materials, the impurity removal box comprising a housing, a screening mechanism, a drive mechanism, and an air blower; a feed opening is formed in the upper end of the housing; the housing is further provided with a discharge opening, an air inlet, and an air outlet; the air inlet and the air outlet are located below the feed port; the air outlet is smaller than the air inlet and the air outlet; the screening mechanism is arranged within the housing and is provided with a screening shaft and multiple layers of coarse screening screens; the screening shaft is rotatably supported on the housing; the multiple layers of coarse screening screens are supported on the screening shaft from top to bottom; the meshes of all the coarse screening screens are sequentially increased from top to bottom; and the drive mechanism serves to rotate the screening shaft.With the impurity removal box, on the one hand, dust and light impurities mixed in the feed raw materials are discharged by airflow generated by the air blower, and on the other hand, the multiple layers of rotary coarse screens are arranged to screen and separate the feed raw materials and the solid impurities, so that the impurity removal box is convenient to operate and has the good foreign matter separation effect.

[0005] WO 2004 / 048006 A1 relates to a method and a device for separating dust particles from granules. For this purpose, a screening drum arranged in a container is filled with the granules in a filling position. In an operating position, the granules are cleaned of dust in the screening drum by an air stream flowing into the device via the air inlets. In an emptying position, the dedusted granules are removed from the device through the emptying opening.

[0006] FR 462 736 A shows a screening device for crushing and subsequently sieving material, wherein the screening device has a conical sieve in a conical housing, which transports fine sieved material through the outlet opening and non-comminuted material is discharged via the outlet opening on the sieve bottom.

[0007] WO 91 / 08059 A1 shows a screening device with an inlet for the material to be screened and an outlet for the screened material arranged in a side wall. A grinding body driven by a motor is arranged in the screen.

[0008] US 6 216 875 B1 shows a screening device having a transfer air inlet arranged on the side wall.

[0009] US 2004 / 056128 A1 discloses an impact mill comprising a cylindrical housing in which both a polygonal screen and a circular screen surrounding the polygonal screen are arranged. The material to be screened is fed through the inlet of the impact mill and crushed by means of the rotating blades arranged on the housing base and the guide vanes surrounding them. It is then conveyed through the screens toward the outlet. The conveyance of the material to be screened is improved by the addition of transfer air at the inlet.

[0010] CH 631 358 A5 discloses a screening device according to the preamble of claim 1 and a hammer mill with a material inlet. The hammer mill has a material feed device upstream of the material inlet, open at the top, which has a flap arranged on a two-armed lever for closing an inlet of the material feed device for receiving ground material. The material feed device further has a main suction air inlet that can be closed by a flap, the main suction air flow of which conveys the ground material from the material feed device upstream of the hammer mill into the hammer mill, and a secondary suction air inlet that can be closed by a flap for controlling the feed of ground material depending on the nature of the grain (hard or easy to grind).

[0011] A disadvantage of such prior art screening devices for granules, in which, for example, the moist granules are to be transferred to a dryer, is that these screening devices have or require a large overall height, and thus, the spatial possibility for implementing a process plant equipped with a known screening device must be available. Another disadvantage of the known screening devices is that, due to the at least partially conical shape of the suction shoe of the screening housing of the known screening device, the product transfer to the screened granules is significantly restricted by adhesions or deposits of granules in the conically shaped area (suction shoe) of the screening housing.

[0012] The object of the invention is to provide a screening device which, while minimising the adhesion or deposits of granulate on the screening housing, requires a lower overall height and thus eliminates the disadvantages of the prior art.

[0013] This object is achieved by a screening device according to claim 1.

[0014] This advantageously significantly reduces the required height of the screening device, making it easier to install in existing process plants, for example. The height is significantly reduced, for example, by eliminating the conical area below the screen, also known as a suction shoe, which is required according to the state of the art. This prevents adhesion or deposits of granules in the screen housing, especially in the area of ​​the screened granules' outlet opening, thus ensuring a sufficiently fast and effective product transfer to the screened granules throughout the entire operation.

[0015] The compact design according to the invention saves the required height of the screening device due to the elimination of the suction shoe and at the same time also reduces the inner surface of the screening housing that comes into contact with the product.

[0016] The screening device according to the invention is particularly preferably used for screening moist and / or dry granules, particularly preferably for a screening process following a wet granulation process or a drying process in a fluidization apparatus, for example in a fluidized bed or the like.

[0017] In an advantageous embodiment, the screen housing has a cylindrical design, with the side wall of the screen housing being at least partially conical. This geometric design of the screen device saves additional installation space, allowing the screen device according to the invention to be even better integrated into existing systems.

[0018] In particular, it has been shown that the outlet opening for the screened granules (product) located on the screen housing is particularly preferably positioned tangentially to the side wall of the screen housing. The tangential arrangement of the outlet opening for the granules on the side wall of the screen housing results in optimized removal of the screened granules. Furthermore, the tangential arrangement minimizes adhesions or deposits in the area of ​​the outlet opening and ensures fast and trouble-free transport of the screened granules.

[0019] In a preferred embodiment, the outlet opening for the screened granules is located above the transfer air inlet. Due to the tangential flow / movement of the transfer air in the screen housing, centrifugal forces act on the granules, driving or transporting them upwards. Therefore, it is advantageous to position the outlet opening for the screened granules (product) above the transfer air inlet.

[0020] In addition, the screening device is preferably designed such that the screen arranged in the screen housing is shaped to match the design of the screen housing. This reduces the inner surface of the screen housing that comes into contact with the product, i.e., minimizes potential areas for adhesion or deposits in the screen housing, thus ensuring fast and trouble-free transport of the screened granules.

[0021] In a particular embodiment of the screening device according to the invention, the screening device has a grinding body arranged in particular in the screening housing. The advantage of a grinding body arranged in the screening housing is that it allows the granules to be pressed through the screen more effectively. The grinding body thus optimizes the screening process.

[0022] In a preferred embodiment of the screening device in this regard, the grinding body arranged in the screen housing is positioned above the screen. The grinding body arranged in the screen housing is arranged so as to be rotatable; particularly preferably, the grinding body is driven by a motor, in particular an electric motor or the like. This further optimizes the screening process.

[0023] The grinding body arranged in the sieve housing is particularly preferably designed to match the shape of the sieve. This adaptation of the grinding body to the shape of the sieve significantly improves the performance of the sieving process, as the granulate to be sieved is forced through the sieve under continuous and consistent pressure by the grinding body, which is adapted to the shape of the sieve.

[0024] In an additional preferred embodiment of the screening device according to the invention, the screening device has an inlet opening for transfer air, wherein the inlet opening for transfer air is preferably arranged on the side wall of the screening housing, particularly preferably tangentially on the side wall of the screening housing. Gaseous media, preferably air but also inert gases, are referred to as transfer air. The supply of transfer air improves product transport. In addition, an air flow is generated in the screening housing of the screening device, which minimizes or completely prevents adhesions or deposits of granulate on the inner surface of the screening housing. In particular, the preferably lateral, but particularly preferably tangential arrangement of the inlet opening for transfer air creates very good flow conditions for the transfer air in the screening housing to prevent adhesions or deposits.Deposits of granules and with regard to the transport of granules through the outlet opening.

[0025] According to a further preferred embodiment of the inventive screening device, the screening device comprises a rotor disk, which is arranged in particular between the screen arranged in the screen housing and the bottom of the screen housing and is particularly preferably at least partially conical. The advantage of a rotor disk arranged between the screen and the bottom of the screen housing is that it serves to protect the seal beneath the screen and to prevent product from remaining on the bottom, i.e., on the lower horizontal plane of the screen housing.

[0026] Particularly preferably, the rotor disc is arranged on a shaft that can be driven by a motor, thereby ensuring improved transfer of the screened granules.

[0027] The invention is explained in more detail below with reference to the accompanying drawings, which show: Figure 1 shows a simple schematic representation of a basic structure of a granulation line known from the prior art with a screening device at the outlet of a high-shear granulator, Figure 2 shows a cross-sectional view of a detailed view of a screening device known from the prior art according to section A of Fig. 1 , Figure 3 shows a cross section of a first embodiment of a screening device according to the invention with an outlet opening for the granulate arranged laterally on the screen housing and an inlet opening for transfer air arranged laterally on the screen housing, Figure 4 shows a cross section of a second embodiment of a screening device according to the invention with a rotor disc arranged in the screen housing and an outlet opening for the granulate arranged laterally on the screen housing according to section plane XX in Fig. 5 , Figure 5 is a plan view of the second embodiment of the screening device according to the invention with an outlet opening for the granulate arranged laterally on the screen housing and an inlet opening for transfer air arranged laterally on the screen housing, Figure 6 is a cross-sectional view of a schematic representation of a high-shear granulator with the screening device according to the invention arranged thereon, and Figure 7 is a plan view of the in Fig. 5 shown schematic representation of a screening device according to the invention arranged on a high-shear granulator.

[0028] In the Fig. 1 A simple schematic representation of the basic structure of a granulation line 1 known from the prior art is shown. For example, in order to transfer the moist granulate from a high-shear granulator 2 into a dryer 3, a transfer of the granulate is necessary. This transfer is currently realized either via gravity feeding of the dryer 3 or via pneumatic conveying. In the case of gravity feeding, the granulate falls into the dryer 3 driven by its own mass. However, this type of feeding requires a large installation height and the spatial possibility of implementing the granulation line 1. Fig. 1 In the granulation line 1 shown, a screening device 4 is shown at the outlet of the high-shear granulator 2 between the high-shear granulator 2 and the dryer 3. The outlet of the screening device 4 is connected to the dryer 3 via a flexible hose line 5.

[0029] Fig. 2 shows a cross-section of a detailed view of a screening device 4 known from the prior art according to section A of Fig. 1 for carrying out a screening process of granules, in particular for a screening process following a wet granulation process or a drying process in a fluidized bed.

[0030] The screening device 4 comprises a screening housing 8 having a lid 6 and a side wall 7. The screening housing 8 additionally has an inlet opening 9 for the granules arranged in the lid 6 of the screening housing 8 and an outlet opening 10 arranged on the screening housing 8. A screen 11 for screening the granules is arranged in the screen housing 8 such that the granules entering via the inlet opening 9 are completely received by the screen 11. In the screen housing 8, a grinding body 14 is also assigned to the screen 11, which is driven on a shaft 12 by a motor M to rotate in the direction of arrow 13. In order to ensure the transfer of the granules, for example into a dryer 3 after screening, transfer air is supplied to the screening device 4 via inlet openings above and below the screen 11.The supply of transfer air to the screening device 4 is realized above the screen 11 via a first inlet opening 15 arranged in the cover 6 and via a second inlet opening 16 arranged after the screen 11.

[0031] The granulate, which is emptied into the screening device 4 via the inlet opening 9 arranged in the lid 6, is pressed through the meshes of the screen 11 by the rotating grinding body 14. At the beginning of the granulate emptying process of the high-shear granulator 2, which is arranged upstream in the exemplary embodiment, most of the granulate is emptied at once into the screen 11 of the screening device 4. As a result, the inlet opening 9 and the outlet opening 10 of the screening device 4 often become blocked before and after the screen 11 arranged in the screen housing 8. The blockages arise, for example, due to adhesions or deposits of granules on the inner surface 17 of the screen housing 8 that is in contact with the granules, preferably in the conical area 18 of the screen housing 8, since the conical area 18 greatly reduces the area available for the granules to pass through the screen housing 8 to the outlet opening 10 of the screen housing 8.For example, in real applications, the diameter of the screen housing 4 is reduced from 400 mm to a diameter of the outlet opening 10 of 100 mm. Furthermore, with the prior art design of the screen device 4, rounded lumps of granulate are usually formed, which cannot be conveyed through the screen 11 and thus remain as waste in the screen 11.

[0032] In Fig. 3 a cross-section of a first embodiment of a screening device 104 according to the invention is shown, with an outlet opening 110 for the granulate to be screened arranged laterally on the screen housing 108 and an inlet opening 116 for transfer air arranged laterally on the screen housing 108.

[0033] The screening device 104 according to the invention for carrying out a screening process for granulate, in particular for a screening process following a wet granulation process or a drying process in a fluidized bed, according to the first exemplary embodiment comprises a screening housing 108 having a bottom 119, a lid 106 and a side wall 107. In addition, the screening device 104 has an inlet opening 109 arranged on the screening housing 108, an outlet opening 110 arranged on the screening housing 108, a sieve 111 arranged in the screening housing 108 and a grinding body 114 arranged in the screening housing 108, wherein the outlet opening 110 arranged on the screening housing 108 is arranged in the one-piece side wall 107 of the screening housing 108, particularly preferably tangentially to the side wall 107 of the screening housing 108.While the product flow according to the screening device known in the prior art was from top to bottom, in the new geometry of the screening device 104 according to the invention, the screened granules are sucked out through the outlet opening 110 arranged on the side wall 107 of the screening housing 108.

[0034] In the embodiment according to Fig. 3 the sieve housing 108 has a cylindrical design, conical over its entire height H, tapering from the cover 106 to the base 118 of the sieve housing 108. Other configurations of the design are conceivable. In the first exemplary embodiment, the side wall 107 is designed as a single piece, a conically shaped side wall 107. However, the side wall 107 can also be designed in several parts, i.e., having at least two side wall sections. In addition, a plurality of inlet openings 109 and outlet openings 110 can be arranged on the sieve housing 108. The number, position and / or geometry of the inlet openings 109 is variable. With regard to the outlet openings 110, at least the number and / or the geometry is variable. The position of the outlet openings 110 is at least limited in that at least one of the outlet openings 110 is arranged laterally on the sieve housing 108.

[0035] The Fig. 3 The screening device 104 shown also comprises a grinding body 114 mounted on a shaft 112 which is driven rotatably in the direction of arrow 113, preferably by a motor M, particularly preferably by an electric motor or the like. The grinding body 114 is adapted in shape to the screen 111, so that the granules can be pressed through the meshes of the screen 111 by the grinding body 114 in an improved manner under continuously constant pressure. For an additional improved transfer of the granules to be screened through the screening device 104 having the screen 111, transfer air is supplied to the screening device 104 via the inlet opening 116. In the exemplary embodiment, an inlet opening 116 is arranged on the side wall 107 of the screen housing 108. The inlet opening 116 can also be designed to be variable in number, position and / or geometry. Preferably, the inlet opening of the transfer air 116 is below the outlet opening 110 for the screened granulate (product), i.e. exactly the opposite as in Fig. 3 shown, arranged laterally on the sieve housing 108. Due to the tangential movement of the air, the centrifugal forces act on the granulate and drive or transport it upwards towards the outlet opening 110, which is preferably arranged above the inlet opening of the transfer air 116.

[0036] The geometry of the sieve housing 108, sieve 111, and / or grinding media 114 are preferably coordinated with one another, as also explained in the first exemplary embodiment, to further optimize the sieving process. By coordinating the different geometries, not only the overall height is reduced by eliminating the need for an additional suction shoe, but also the internal free surface of the sieve device, in particular the sieve housing, is minimized.

[0037] The granules appear in Fig. 3 In the first exemplary embodiment shown, the granules enter the screening device 104 via the inlet opening 109. Due to the coordinated geometries of the screening housing 108, screen 111, and grinding media 114, few adhesions or deposits form, since the inner surface 117 touched by the granules during the screening process is minimal. In addition, fewer granule adhesions or deposits form in the circumferential direction of the screening housing 108 or are transported further more quickly via the outlet opening 110, since optimized flow conditions can be created in the screening housing 108 by the transfer air flowing in laterally via the inlet opening 116 in conjunction with the minimal contact with the inner surface 117. The screened granules are sucked off through the outlet opening 110 arranged on the side wall 107 of the screening housing 108.

[0038] Fig. 4 shows a cross section of a second embodiment of a screening device 204 according to the invention with a rotor disc 220 arranged in the screening housing 208 and an outlet opening 210 for the granulate arranged laterally on the screening housing 208 according to section plane XX in Fig. 5 .

[0039] The second exemplary embodiment according to the invention, like the first exemplary embodiment, also comprises a sieve housing 208 having a bottom 219, a lid 206 and a side wall 207. The sieve device 204 additionally has an inlet opening 209 for the granulate arranged on the sieve housing 208, an outlet opening 210 for the sieved granulate (product) arranged on the sieve housing 208, a sieve 211 arranged in the sieve housing 208 and a grinding body 214 assigned to the sieve 211 in the sieve housing 208, wherein the outlet opening 210 for the sieved granulate arranged on the sieve housing 208 is arranged in the side wall 207 of the sieve housing 208, particularly preferably tangential to the side wall 207 of the sieve housing 208. The grinding body 214 assigned to the sieve 211 is arranged on a shaft 212 which is rotatably driven in the direction of arrow 213 by a motor M, preferably an electric motor or the like.The grinding body 214 is arranged above the sieve 211 in the sieve housing 208, whereby the granulate to be sieved is continuously pressed through the sieve 211 at a constant pressure. The sieving device 204 of the second embodiment according to . Fig. 4 has an inlet opening 216 for transfer air, not shown here.

[0040] The statements made for the first embodiment of the invention with regard to the side walls, inlet, entry and exit openings, etc. can be transferred to the second embodiment of the invention to the same extent.

[0041] The inventive screening device 204 according to the second exemplary embodiment has a cylindrical design of the screening housing 208, wherein the design of the screening housing 208 of the screening device 204 tapers conically from the cover 206 to the bottom 219 over the overall height H of the screening housing 208. The screen 211 arranged in the screening housing 208 of the screening device 204 is designed to correspond to the design of the screening housing 208. Furthermore, the grinding body 214 arranged in the screening housing 208 of the screening device 204 is designed to correspond to the design of the screen 211. As a result, the screening housing 208, screen 211, and grinding body 214 are optimally matched to one another.

[0042] In contrast to the screening device 104 of the first embodiment, the screening device 204 additionally has a rotor disk 220. The rotor disk 220 is arranged between the screen 211 and the bottom 219 of the screen housing 208 of the screening device 204. The rotor disk 220 is arranged on a shaft 212 that can be driven by the motor M. Thus, the rotor disk 220 and the grinding body 214 are mounted on a shaft 212 and are always driven at the same rotational speed. It is also conceivable for the rotor disk 220 and the grinding body 214 of the screen 211 to be driven independently of one another, for example, each via a separate motor, in particular an electric motor or the like. In this case, the rotor disk 220 and the grinding body 214 are arranged on different shafts. The rotor disk 220 of the screening device 204 is preferably at least partially conical.The arrangement of the rotor disc 220 serves to protect the seal below the sieve 211 and to prevent product from remaining on the bottom 219 and not being transported further toward the suction of the outlet opening 210. This achieves an even better and more complete transfer of the product and minimizes adhesions or deposits of the granules in the area of ​​the bottom 211 of the sieve housing 208 and the side wall 207 of the sieve housing 208.

[0043] A further improvement in the product transfer is achieved in that the inlet opening 216 for transfer air, not shown here, is arranged on the side wall 207 of the sieve housing 208; preferably, the inlet opening 216 for transfer air, not shown here, is arranged tangentially on the side wall 207 of the sieve housing 208.

[0044] In Fig. 5 is a plan view of the second embodiment of the screening device 204 according to the invention with an outlet opening 210 for the granulate arranged laterally on the screening housing 208 and an inlet opening 216 for transfer air. The grinding body 214, arranged on a shaft 212 driven by a motor M, is arranged above the screen 211 in the screening housing 208, which has a cover 206 (not shown here), a base 219 (not shown) and a side wall 207, and is located in the sectional plane XX. The inlet opening 216 for the transfer air is arranged laterally offset from the sectional plane XX on the side wall 207 of the screening housing 208.

[0045] The rotation of the grinding body 214 in the direction of arrow 213 presses or pushes the granules through the sieve 211. The sieving process is optimized by the transfer air entering the inlet opening 216. The combination of the rotating grinding body 214 and the transfer air results in an improved sieving process for the granules.

[0046] Fig. 6 shows a cross-section of a schematic representation of part of a high-shear granulator 2 with a third embodiment of a screening device 304 according to the invention arranged on the high-shear granulator 2. The inlet opening 316 for the transfer air is arranged tangentially on the cylindrical screen housing 308 of the screening device 304. The outlet opening 310 is also arranged tangentially on the cylindrical screen housing 308 of the screening device 304. In the exemplary embodiment, the inlet opening 316 lies in the horizontal sectional plane YY through the screening device 304, while in the third exemplary embodiment, the outlet opening 310 lies in the likewise horizontal sectional plane ZZ through the screening device 304. In the third exemplary embodiment, the horizontal sectional planes YY and ZZ are offset from one another above the overall height H of the screen housing 308 of the screening device 304. However, such an offset between the section planes YY and ZZ is not mandatory.In the third embodiment, the transfer air is supplied to the sieve housing 308 of the sieve device 304 through the inlet opening 316 and is located at a higher position in the x-direction of the sieve housing 308 of the sieve device 304 compared to the outlet of the sieved granulate through the outlet opening 310 of the sieve housing 308 of the sieve device 304.

[0047] The statements made for the first embodiment of the invention with regard to the side walls, inlet, entry and exit openings, etc., can be transferred to the third embodiment of the invention to the same extent.

[0048] The granulate enters the screening device 304 from the high-shear granulator 2 and is pressed through the screen 311 by a grinding body 314 (not shown here) with a constant pressure continuously distributed across the screen 311. Transfer air also enters the screen housing 304 of the screening device 308 through the inlet opening 316 arranged in the upper region of the screen housing 308 tangentially to the side wall 307 of the screen housing 308, and a spiral-shaped downward air flow is generated within the cylindrical screen housing 308 of the screening device 304, counter to the x-direction. This air flow transports, on its way through the sieve housing 308, for example, granules adhering to or deposited on the sieve housing 308 in the direction of the outlet opening 310 and thus prevents the sieve device 304 from becoming blocked by the granules themselves.The outlet opening 310 arranged tangentially on the side wall 307 of the sieve housing 308 also ensures optimal suction of the granulate and the transfer air.

[0049] In Fig. 7 a top view of the Fig. 6 1 shows a schematic representation of a screening device 304 according to the invention arranged on a high-shear granulator 2 according to a third exemplary embodiment. It can be seen that the inlet opening 316 for transfer air and the outlet opening 310 for the product are arranged on the same side of the screening housing 308. Furthermore, both the inlet opening 316 and the outlet opening 310 extend tangentially to the side wall 307 of the screening housing 308 of the screening device 304.

[0050] With each of the geometries used in the screening devices 104, 204 and 304 according to the invention, it is sufficient to suck in the transfer air, preferably via an outlet opening 110, 210 or 310 arranged tangentially on the side wall 107, 207 or 307, and thereby achieve a fast and reliable product transfer.

Claims

1. A screen apparatus (104, 204, 304) for screening granules, in particular wet and / or dry granules, comprising (a) a screen housing (108, 208, 308) comprising a bottom (119, 219, 319), a cover (106, 206, 306) and a side wall (107, 207, 307), (b) an inlet opening (109, 209) for the granules, which is arranged on the screen housing (108, 208, 308), (c) an outlet opening (110, 210, 310) for the screened granules, arranged laterally on the screen housing (108, 208, 308) , (d) a screen (111, 211, 311) arranged in the screen housing (108, 208, 308) , and (e) an inlet opening (116, 216, 316) for transfer air arranged laterally on the screen housing, characterized in that the inlet opening (116, 216, 316) for transfer air and the outlet opening (110, 210, 310) for the screened granules are arranged on the side wall (107, 207, 307) of the screen housing (108, 208, 308), wherein the inlet opening (116, 216, 316) for transfer air and the outlet opening (110, 210, 310) for the screened granules are each arranged downstream of the screen (111, 211, 311).

2. Screen apparatus (104, 204, 304) according to claim 1, characterized in that the screen housing (108, 208, 308) comprises a cylindrical design.

3. Screen apparatus (104, 204, 304) according to claim 1 or claim 2, characterized in that the screen housing (108, 208, 308) is at least partially conical in design.

4. Screen apparatus (104, 204, 304) according to one of the preceding claims, characterized in that the outlet opening (110, 210, 310) for the screened granules, which is arranged on the screen housing (108, 208, 308), is arranged tangentially to the side wall (107, 207, 307) of the screen housing (108, 208, 308).

5. Screen apparatus (104, 204, 304) according to one of the preceding claims, characterized in that the outlet opening (110, 210, 310) is arranged above the inlet opening (116, 216, 316) for transfer air.

6. Screen apparatus (104, 204, 304) according to one of the preceding claims, characterized in that the screen (111, 211, 311) arranged in the screen housing (108, 208, 308) corresponds to the design of the screen housing (108, 208, 308).

7. Screen apparatus (104, 204, 304) according to one of the preceding claims, characterized in that the screen apparatus (104, 204, 304) comprises a grinding body (114, 214, 314) arranged in the screen housing (108, 208, 308), whereby the grinding body (114, 214, 314) arranged in the screen housing (108, 208, 308) is expediently arranged above the screen (111, 211, 311).

8. Screen apparatus (104, 204, 304) according to claim 7, characterized in that the grinding body (114, 214, 314) arranged in the screen housing (108, 208, 308) is configured to correspond to the design of the screen (111, 211, 311).

9. Screen apparatus (104, 204, 304) according to one of claims 6 or 7, characterized in that the grinding body (114, 214, 314) arranged in the screen housing (108, 208, 308) is rotatable.

10. Screen apparatus (104, 204, 304) according to one of claims 6 to 8, characterized in that the grinding body (114, 214, 314) arranged in the screen housing (108, 208, 308) can be driven by means of a motor (M).

11. Screen apparatus (104, 204, 304) according to one of the preceding claims, characterized in that the inlet opening (116, 216, 316) for transfer air is arranged on the side wall (107, 207, 307) of the screen housing (108, 208, 308).

12. Screen apparatus (104, 204, 304) according to claim 11, characterized in that the inlet opening (116, 216, 316) for transfer air is arranged tangentially on the side wall (107, 207, 307) of the screen housing (108, 208, 308).

13. Screen apparatus (104, 204, 304) according to one of the preceding claims, characterized in that the screen apparatus (104, 204, 304) comprises a rotor disc (220).

14. Screen apparatus (104, 204, 304) according to claim 13, characterized in that in that the rotor disc (220) is arranged in the screen housing (108, 208, 308) between the screen (111, 211, 311) and the bottom (119, 219, 319) of the screen housing (108, 208, 308).

15. Screen apparatus (104, 204, 304) according to claim 14, characterized in that the rotor disc (220) can be driven by means of a motor (M), whereby the rotor disc (220) is expediently configured at least partially in the design of a cone.