Sieving device and pneumatic conveying system with such a sieving device

Abstract

Sieve device for a pneumatic conveying line comprising a. a housing (14) with a feed opening (15) and with a discharge opening (16), b. a stationary sieve base body (20; 20a) arranged in the housing (14) between the feed opening (15) and the discharge opening (16), comprising i. a sieve longitudinal axis (24) and ii. several profile strips (25; 25a) which are arranged at least sectionally around the longitudinal axis (24) of the sieve, wherein the sieve base body (20; 20a) has an inlet opening facing the feed opening (15).

Description

[0001] The invention relates to a sieving device for bulk material and a pneumatic conveying system with such a sieving device.

[0002] DE 10 2021 207 890 A1 discloses a device and a method for pneumatically conveying powder as well as a pneumatic conveying system with such a device.

[0003] DE 16 07 642 A discloses a method and a device for separating a coarse fraction from a pneumatically conveyed bulk material stream.

[0004] When conveying bulk materials, especially powders, agglomerates can form due to the manufacturing process, which can be problematic in downstream processing. Perforated sheet metal screen baskets are known for separating agglomerates from a pneumatic conveying stream. Cleaning these screen baskets is complex. To ensure the system's operation, two screens connected in parallel and switched alternately are required. The technical effort required to implement this parallel connection is considerable.

[0005] The object of the present invention is to improve the removal of agglomerates during the pneumatic conveying of bulk material, in particular to enable the removal of agglomerates reliably and easily.

[0006] This problem is solved according to the invention by a sieving device with the features specified in claim 1 and by a pneumatic conveying system with the features specified in claim 12.

[0007] According to the invention, a sieve device comprises a sieve base body with several profile strips arranged at least partially around a longitudinal sieve axis. The sieve base body is statically designed and arranged in a housing of the sieve device. The sieve base body is, in particular, fixed to the housing. The sieve base body is, in particular, arranged eccentrically within the housing. The sieve base body is, in particular, drum-shaped. The sieve base body is arranged between a feed opening and a discharge opening in the housing and has an inlet opening for a pneumatic conveying flow. The inlet opening of the sieve base body faces the feed opening of the housing. In particular, the feed opening and / or the inlet opening are arranged vertically downwards.

[0008] The sieving device is particularly suitable for the pneumatic conveying of powdered bulk material. The powder is, in particular, plastic powder and especially purified terephthalic acid (PTA). The particle size of the PTA powder is, in particular, between 80 µm and 120 µm. It has been recognized that the sieving device is particularly advantageous for the pneumatic conveying of PTA powder because agglomerates can form in a dryer located upstream of the sieving device, which are detrimental in a downstream manufacturing process, especially in PET production. Agglomerates with a mean diameter of at least 1 mm, in particular at least 3 mm, in particular at least 5 mm, and in particular at least 10 mm are sieved out of a pneumatic conveying stream by means of the sieve body.

[0009] The inlet opening of the sieve body results in particular from a circumferential angle of the profile strips and / or their arrangement in a plane perpendicular to the longitudinal axis of the sieve. The circumferential angle is in particular at least 90°, in particular at least 120°, in particular at least 180°, in particular at least 240°, and in particular at least 270°.

[0010] In particular, the profile strips are arranged concentrically around the longitudinal axis of the screen. In this case, the profile strips are each arranged parallel to the longitudinal axis of the screen. Alternatively, the profile strips can each be arranged in a plane oriented transversely, in particular perpendicularly, to the longitudinal axis of the screen. In this case, the profile strips are arranged in a row along the longitudinal axis of the screen.

[0011] The screen body is designed as a static slotted screen. This screen body enables robust and reliable removal of agglomerates from the conveyed stream. The screen is particularly suitable for high pneumatic conveying throughput rates, specifically at least 150 t / h, at least 175 t / h, at least 200 t / h, at least 250 t / h, at least 300 t / h, at least 350 t / h, and at least 400 t / h. A pneumatic conveying line connected to the screen can have a nominal diameter of at least 150 mm, at least 200 mm, and at least 250 mm.

[0012] The profile strips each have a longitudinal axis that is oriented transversely and, in particular, perpendicularly with respect to the longitudinal axis of the screen. The longitudinal axes of the profiles are, in particular, at least partially non-linearly oriented, especially curved, and in particular circular. The longitudinal axis of the profile can also be polygonal. This means that each profile strip is arranged around the longitudinal axis of the screen, thus exhibiting a corresponding curvature or polygonal contour. In particular, each profile strip is arranged in a plane that is oriented perpendicular to the longitudinal axis of the screen. The profile strips are, in particular, oriented parallel to each other.

[0013] Alternatively, the profile strips can be arranged at least partially parallel to the longitudinal axis of the screen. Several profile strips are arranged, in particular, along a curved, especially circular, or polygonal contour around the longitudinal axis of the screen. This means that each profile strip runs linearly on its own. The arrangement of the profile strips forms the basic screen body, which extends section by section around the longitudinal axis of the screen.

[0014] The profile strips are each made of a robust material, in particular metal, in particular steel, in particular stainless steel, in particular an austenitic corrosion-resistant stainless steel, which in particular has a reduced carbon content of at most 0.03% and / or an increased chromium content of at least 17.5% and / or an increased nickel content of at least 8.0%, in particular with the material number 1.4307.

[0015] The profile strips are designed identically.

[0016] In particular, a housing nozzle is attached to the feed opening and / or the discharge opening to simplify coupling to a conveying line.

[0017] Profile strips according to claim 2 enable efficient screening performance, in particular the efficient removal of interfering agglomerates. Furthermore, the profile strips allow for straightforward and, in particular, trouble-free cleaning of the screen body. Specifically, a cleaning tool, especially a rake, can penetrate a screen gap formed between the profile strips and remove agglomerates and / or deposits. The risk of clogging of the screen body and the associated increase in pressure loss across the screening device are prevented. In particular, the trapezoidal profile cross-section is symmetrical and, in particular, isosceles. Specifically, the interior angles on the long base of the trapezoid are at least 60°, in particular at least 70°, in particular at least 80°, and in particular at least 85°.In particular, the height of the trapezoid is greater than the longer base, in particular by a factor of 1.5 and in particular by at least twice the length. In particular, the shorter base of the trapezoid is at most 20 mm, in particular by a factor of 15 mm, in particular by a factor of 10 mm, in particular by a factor of 8 mm and in particular by a factor of 5 mm. The longer base of the trapezoid is in particular at least 0.5 mm, in particular at least 1.0 mm, in particular at least 1.5 mm, in particular at least 2.0 mm, in particular at least 2.5 mm, in particular at least 3.0 mm and in particular at least 5.0 mm.

[0018] The length ratio of the shorter base side to the longer base side is, in particular, at most 0.5, in particular at most 0.4, in particular at most 0.3, in particular at most 0.25, in particular at most 0.2 and in particular at most 0.1.

[0019] Alternatively, the profile strips can each have a triangular profile cross-section, which corresponds to a trapezoidal shape as described above, with the shorter base side having a length of 0.

[0020] Alternatively, the profile strips can also have a rectangular profile cross-section, so that the opposite base sides are of the same length, i.e., have a length ratio of 1.0.

[0021] A sieve body according to claim 3 has an advantageous sieving function. The sieve body is robustly constructed. The sieve gap has a maximum gap width facing the longitudinal axis of the sieve. The maximum gap width is, in particular, at least 5 mm, in particular at least 7 mm, in particular at least 9 mm, in particular at least 10 mm, in particular at least 12 mm, and in particular at least 15 mm. A minimum gap width is arranged on an outer side of the profile strips facing away from the longitudinal axis of the sieve. The minimum gap width is, in particular, at most 5 mm, in particular at most 4 mm, in particular at most 3 mm, in particular at most 2 mm, and in particular at most 1 mm.

[0022] A sieve device according to claim 4 enables advantageous manufacturing of the sieve body. The sieve body is, in particular, manufactured in one piece. Specifically, the support strips are alternately and, in particular, permanently joined to the profile strips, especially by welding. The support strips are, in particular, arranged on the outer side of the profile strips facing away from the longitudinal axis of the sieve.

[0023] A rake according to claim 5 simplifies the cleaning of the sieve body. In particular, reliable and robust cleaning of the sieve gaps is ensured.

[0024] A sieving device according to claim 6 simplifies automated, and in particular controlled and regulated, cleaning of the sieve body. By means of a motorized rake drive, the at least one rake can clean the sieve gaps without manual intervention. In an arrangement where the individual profile strips are curved or polygonal, the motorized rake drive is in particular designed as a rotor, which is in particular arranged concentrically to the longitudinal axis of the sieve. In an embodiment where the profile strips are parallel to the longitudinal axis of the sieve, the motorized rake drive is in particular a linear drive, in particular a pneumatic cylinder or linear motor.

[0025] The screen enables, in particular, the cleaning of the screen body in the circumferential and radial directions relative to the longitudinal axis of the screen. Smaller agglomerates are forced through the screen gap in the radial direction. Larger agglomerates are combed out in the circumferential direction.

[0026] It is particularly advantageous to use a control unit to perform sensor-controlled and regulated cleaning of the screen body. Cleaning can be performed, in particular, when an increased pressure drop is generated by the screen body. Additionally or alternatively, sensor-controlled and regulated cleaning can be performed time-dependently and / or process-dependently, depending on the material properties of the conveyed bulk material. For example, more frequent cleaning steps, especially continuous cleaning, are advantageous during the start-up and shutdown processes of the pneumatic conveying system due to increased agglomerate density. Undesirable and disruptive contaminants can be reliably removed. Alternatively, in a steady-state operating condition of the pneumatic conveying system, cleaning can be performed less frequently, as the occurrence of Agglomerates and / or caking are reduced. Cleaning effort is reduced.

[0027] It was found, in particular, that the tendency of bulk material to agglomerate can depend on a prior processing step, especially in a dryer. It is particularly advantageous to record the frequency of agglomerate formation as a function of the conditions in a processing step and to adjust the control of screen cleaning accordingly. In particular, cleaning can be carried out continuously in a cleaning plant.

[0028] One embodiment of the sieve device according to claim 7 simplifies the accessibility of the sieve base body within the housing. In particular, it was found that the sieve base body can advantageously be attached to side covers of the housing.

[0029] A sieve device according to claim 8 is structurally uncomplicated and can be directly integrated into a linear pneumatic conveying line.

[0030] Alternatively, it is possible that the inlet and outlet openings allow for a deflection of the fluid flow, in particular with a deflection angle of at least 45° and especially at least 90°.

[0031] At least one comminution tooth according to claim 9 simplifies the comminution of agglomerates that are combed out of the screen slots by the rake. In particular, the screen has several comminution teeth, which are preferably designed in the form of a comminution bar, also referred to as a crushing bar. In particular, the comminution bar is designed as a slotted bar, the number of slots corresponding to the number of screen slots between the profile bars. The comminution teeth are preferably formed integrally with the comminution bar. In particular, the comminution bar is arranged on the screen body and preferably attached to it such that the comminution teeth are aligned with the profile bars and the slots are aligned with the screen slots. The rake can be passed through the slots of the comminution bar.The agglomerates are pressed between the rake and the shredding tooth and thereby broken up, particularly into smaller agglomerates. In particular, several shredding teeth are provided, especially one shredding tooth per profile strip.

[0032] An arrangement of the at least one shredding tooth according to claim 10 ensures, on the one hand, uninterrupted use of the sieve body during the regular operation of the sieving device. The at least one shredding tooth is, in particular, arranged outside of a sieve surface relevant to the sieving process. In particular, several shredding teeth are arranged, especially on both sides at the end of the profile strips.

[0033] A sieve holder according to claim 11 simplifies the arrangement and fastening of the sieve base body in the housing. In particular, a particularly advantageous fastening to the side covers of the housing is possible.

[0034] A pneumatic conveying system according to claim 12 essentially has the advantages of the sieving device to which reference is hereby made. The pneumatic conveying system particularly enables the advantageous pneumatic conveying of bulk materials, especially plastic powders or, in particular, PTA powders, especially at high conveying rates. Agglomerates that may occur in a powder dryer are reliably and robustly cleaned out and / or broken up by means of the sieving device according to the invention, in particular broken up repeatedly until the broken particles are passable through the sieving device.

[0035] At the delivery point, a blower is installed to supply pressurized conveying gas into the conveying line. The conveying gas is, in particular, air and / or nitrogen. At the destination point, at least one receiving container, a silo, and / or a system for further processing the bulk material is installed.

[0036] A pneumatic conveying system according to claim 13 enables the powder dryer to be decoupled from the pressure of the conveying gas at the feed point. The metering device is in particular designed as a rotary valve.

[0037] Both the features specified in the claims and those specified in the following exemplary embodiments of a sieve device according to the invention are each suitable, individually or in combination with one another, for further developing the subject matter of the invention. The respective combinations of features do not constitute a limitation with regard to further developments of the subject matter of the invention, but are essentially merely exemplary.

[0038] Additional features, advantageous embodiments, and details of the invention will become apparent from the following description of an exemplary embodiment with reference to the drawing. The drawing shows: Fig. 1 a schematic representation of a pneumatic conveying system for bulk material with a sieving device according to the invention, Fig. 2 a perspective partially cutaway view of a sieve device according to a first embodiment, Fig. 3 a side view of a sieve base body of the sieve device according to Fig. 2, Fig. 4 a side view of the sieve base body in a plane perpendicular to the sieve longitudinal axis, Fig. 5 a partially sectioned longitudinal view of the sieve base body according to Fig. 4, Fig. 6 an enlarged detail view according to Detail VI in Fig. 5, Fig. 7 an enlarged front view of a profile strip of the sieve base body in a plane perpendicular to the profile longitudinal axis, Fig. 8 a Fig. 4. Corresponding side view of the sieve base body of a sieve device according to a second embodiment, Fig. 9 a longitudinal view of the sieve base body according to Fig. 8.

[0039] One in Fig. The conveying system 1, designated as a whole by 1, is a pneumatic conveying system for the pneumatic conveying of bulk material, in particular PTA powder. The conveying system 1 comprises a powder dryer 2, which is connected at a feed point 3 to a pneumatic conveying line 4 by means of a rotary valve 5 as a metering device.

[0040] The powder dryer 2 is designed in particular as a drum dryer, which is rotatably arranged with respect to its longitudinal axis and has a heating element. Several powder dryers may be present. The rotary valve 5 is a feed element for feeding the PTA powder into the conveying line 4.

[0041] The conveying line 4 connects the feed point 3 with a destination point 6, where one or more destination containers 7 are located. The destination containers 7 are, for example, designed as intermediate silos and / or storage silos. The destination containers 7 are directly connected to the pneumatic conveying line 4. For this purpose, the pneumatic conveying line 4 has one or more branch lines 8, which can be controlled, for example, by means of shut-off devices (not shown), in particular gate valves, ball valves, and / or diverter valves.

[0042] Each of the target containers 7 is connected to an exhaust air line 9 to allow for venting of the target containers 7. The exhaust air line 9 can discharge exhaust air from the target container 7 to the environment and / or be configured as a recirculation line for returning the exhaust air, particularly in the form of a closed-loop system. A filter element 10 is installed upstream of the exhaust air line 9 to remove pollutants, especially dust, from the exhaust air.

[0043] For the pneumatic conveying of the PTA powder along the conveying line 4, in particular from the feed point 3 to the target containers 7 at the target point 6, a conveying gas supply 11 and a gas quantity control 12 are provided.

[0044] A screening device 13 is arranged along the conveying line 4, in particular downstream of the feed point 3 and upstream of the destination point 6. Several screening devices 13 may also be present, arranged in parallel and / or in series along the conveying line 4. The pneumatic conveying flow passes through the screening device 13.

[0045] The following will be based on Fig. 2 to 7 the construction of a sieve device according to a first embodiment is explained in more detail.

[0046] The sieve device 13 has a housing 14 with a feed opening 15 and a discharge opening 16. The housing 14 has a housing base 17, each end of which can be closed with a side cover 18. For illustrative purposes, in Fig. 2 Only the rear side cover 18 is shown. The side covers 18 are in particular detachably fastened, in particular screwed.

[0047] In the illustrated embodiment, the inlet opening 15 is located at the bottom and the outlet opening 16 at the top in a vertical direction. The pneumatic conveying flow passes through the sieve device 13 from bottom to top, particularly vertically. Depending on the course of the conveying line 4, other configurations of the sieve device 13 are possible, especially with different arrangements of the inlet opening 15 and / or the outlet opening 16. This relates, on the one hand, to the flow direction of the pneumatic conveying flow through the housing 14 and / or the relative arrangement of the inlet opening 15 and outlet opening 16 on the housing 14. In the illustrated embodiment, the openings 15 and 16 are aligned with each other. It is possible for the openings 15 and 16 to be arranged offset from each other with respect to the flow direction.

[0048] A sieve base 20 is arranged in the housing 14 and is held in the housing by means of a sieve holder 21. The sieve holder 21 is, in particular, frame-like and encompasses the sieve base 20 along its outer circumference, at least partially. The sieve holder 21 has a retaining plate 22 at each end face. Retaining pins 23 project from the end face of at least one of the retaining plates 22. The retaining pins 23 correspond to corresponding recesses in the respective side cover 18. The retaining pins 23 are, in particular, continuous and connect the opposing retaining plates 22.

[0049] The sieve body 20 has a longitudinal sieve axis 24. The sieve body 20 also has several profile strips 25, each extending at least partially around the longitudinal sieve axis 24. It is advantageous if the sieve body 20 has at least five, in particular at least ten, in particular at least 20, in particular at least 30, and in particular at most 100 profile strips 25. Depending on the size of the sieve body 20, more or fewer than the number of profile strips 25 shown may also be used.

[0050] The profile strips 25 are each identical and, in particular, curved along a circular path. According to the illustrated embodiment, the circumferential angle w of the profile strips 25 about the longitudinal axis 24 of the screen is approximately 240°. Depending on the design of the screen base 20 and / or the application, and especially the bulk material being conveyed, the circumferential angle w can also be smaller or larger than 240°.

[0051] The profile strips 25 are each arranged in a plane oriented perpendicular to the longitudinal axis 24 of the screen. The profile strips 25 are oriented parallel to each other. The profile strips 25 are spaced apart from each other along the longitudinal axis 24 of the screen. A screen gap 26 is formed between two adjacent profile strips 25. The screen gap 26 has a gap width b S on.

[0052] The profile strips 25 are connected to each other by means of several support strips 27. The support strips 27 are joined to the profile strips 25, in particular by welding, especially by pressure welding or friction welding. It is advantageous if at least three, in particular at least five, in particular at least ten, in particular at least 15, in particular at least 25 and in particular at most 100 support strips 27 are arranged along the circumference of the profile strips 25. The support strips 27 are each oriented parallel to the longitudinal axis 24 of the sieve and arranged along the outer circumference of the profile strips 25.

[0053] The sieve base body 20 with the profile strips 25 and in particular with the support strips 27, is made in one piece.

[0054] The profile strips 25 each have a trapezoidal profile cross-section, which is in Fig. Figure 7 shows the profile cross-section to be symmetrical and isosceles, with a shorter base 28 and a longer base 29. The shorter base 28 has a longitudinal extent k, and the longer base 29 has a longitudinal extent l. The height h of the profile cross-section, i.e., the perpendicular distance between the shorter base 28 and the longer base 29, is, in particular, at least twice the longitudinal extent l. The acute interior angles on the longer base 29 are equal and measure 70°. In particular, k ≤ 0.5 · l, k ≤ 0.3 · l, and k ≤ 0.2 · l. It is understood that the profile cross-section of the profile strips 25 can also be designed with a different trapezoidal geometry or a different geometry.

[0055] The profile strips 25 are arranged in the sieve body 20 such that the short base side 28 faces away from the longitudinal axis 24 of the sieve. Due to the trapezoidal shape, this results in the sieve gap 26 increasing radially outwards.

[0056] The sieving device has several shredding teeth 30, which, according to the illustrated embodiment, are each arranged at one end side on the profile strips 25. According to the embodiment, the shredding teeth 30 are each integrally formed on a shredding strip 32. The shredding strip 32 extends, in particular, parallel to the longitudinal axis 24 of the sieve. Slots 33 are formed between the shredding teeth 30, which are aligned with the sieve slots 26. The shredding teeth 30 are aligned with the profile strips 25. The shredding strip 32 is attached to the Fig. The shredding bar 32 is arranged at the end of the profile strips 25 shown on the right. It provides additional mechanical stabilization of the screen base body 20 and, in particular, simplifies its placement in the screen holder 21. The shredding teeth 30 project radially into the screen base body 20 from the profile strips 25.

[0057] In particular, each profile strip 25 is assigned a grinding tooth 30. The slot-like grinding gap, which aligns with the sieve gap 26, is formed between two adjacent grinding teeth 30. It is conceivable to additionally or alternatively arrange grinding teeth 30 on the opposite end face of the profile strips 25.

[0058] The sieving device 13 has a rake 31 whose teeth engage in the sieve gap between the profile strips 25. In particular, two rakes 31 are provided, which can be driven by a motor drive, in particular a rotor arranged concentrically to the longitudinal axis 24 of the sieve. As shown in Fig. 2. The rakes 31 rotate, in particular clockwise, so that agglomerates which are combed out in and / or at the screen slots 26 and, in particular, carried along circumferentially by the rake 31, are broken up on the comminution teeth 30. The rakes 31 are attached to the rotor diametrically opposite, in particular on opposite sides, with respect to the longitudinal axis 24 of the screen.

[0059] The sieve device 13 is connected to a control / regulation unit (not shown in detail) in a signal connection, in particular to enable automated and, in particular, controlled operation of the sieve device, and in particular to ensure an automated and, in particular, controlled cleaning function for the sieve device with the at least one rake 31.

[0060] The following refers to Fig. 8 and Fig. Section 9 describes a second embodiment of a sieve body. Structurally identical parts receive the same reference numerals as in the first embodiment, to which reference is hereby made. Structurally different but functionally similar parts receive the same reference numerals with a trailing "a".

[0061] In the sieve body 20a, the profile strips 25a are each linear and oriented parallel to the sieve's longitudinal axis 24. According to this embodiment, the outer geometry of the profile body 20a is defined by the support strips 27a, which are designed around the sieve's longitudinal axis 24, i.e., are curved, and extend along a circular path. The sieve slots 26a are axially oriented, i.e., parallel to the sieve's longitudinal axis 24. The basic construction of the sieve body 20a essentially results from an interchange of profile strips 25a and 27a compared to the first embodiment.

[0062] In the second embodiment, the rake (not shown) with comb is designed in a ring-shaped segment, with the teeth extending radially to engage in the sieve slots 26a. For the cleaning function, the rake is displaced linearly, in particular along the longitudinal axis 24 of the sieve. The shredding teeth 30 are arranged at the ends of the profile strips 25a. Reference symbol list 1 Conveyor system 2 powder dryers 3 Place of departure 4 Conveyor line 5 rotary valve 6 Destination 7 Target Containers 8 branch line 9 Exhaust duct 10 filter elements 11 Supply of process gas 12 Gas quantity control 13 Sieve device 14 cases 15 Feed opening 16 Discharge opening 17 Housing base body 18 side covers 20, 20a Sieve base 21 Sieve holder 22 Retaining plate 23 retaining pins 24 Sieve longitudinal axis 25, 25a Profile strip 26, 26a Sieve gap 27, 27a Support strips 28 shorter end page 29 longer end page 30 grinding tooth 31 rakes 32 shredding bar 33 slots w circumferential angle b S Gap width h height k Longitudinal extent of the shorter end side 28 l Longitudinal extent of the longer end side 29

Claims

[1] Sieve device for a pneumatic conveying line comprising a. a housing (14) with a feed opening (15) and with a discharge opening (16), b. a stationary sieve base body (20; 20a) arranged in the housing (14) between the feed opening (15) and the discharge opening (16), comprising i. a sieve longitudinal axis (24) and ii. several profile strips (25; 25a) which are arranged at least sectionally around the longitudinal axis (24) of the sieve, wherein the sieve base body (20; 20a) has an inlet opening facing the feed opening (15). [2] Sieve device according to claim 1, characterized by , that the profile strips (25; 25a) each have a trapezoidal profile cross-section. [3] Sieve device according to one of the preceding claims, characterized by, that the profile strips (25; 25a) are arranged with respect to the sieve longitudinal axis (24) such that a sieve gap (26; 26a) formed between two adjacent profile strips (25; 25a) has a gap width that decreases along a radial direction of the sieve longitudinal axis (24). [4] Sieve device according to any one of the preceding claims, characterized by , that several profile strips (25; 25a) are connected to each other by means of at least one support strip (27; 27a). [5] Sieve device according to any one of the preceding claims, characterized by at least one rake (31) whose teeth engage in the sieve gap (26; 26a) of the sieve body (20; 20a). [6] Sieve device according to claim 5, characterized by , that the at least one rake (31) has a motorized rake drive, in particular a rotor arranged concentrically to the longitudinal axis (24) of the sieve. [7] Sieve device according to any one of the preceding claims, characterized by, that the housing (14) has a detachably attached side cover (18) which is arranged perpendicular to the longitudinal axis (24) of the sieve. [8] Sieve device according to any one of the preceding claims, characterized by , that the inlet opening (15) and the outlet opening (16) define a linear flow direction through the housing (14). [9] Sieve device according to any one of the preceding claims, characterized by at least one comminution tooth (30) which projects radially on the sieve base body (20; 20a) with respect to the sieve longitudinal axis (24), wherein in particular several comminution teeth (30) are arranged on a comminution bar (32). [10] Sieve device according to claim 9, characterized by , that the at least one crushing tooth (30) is arranged at the end of a profile strip (25; 25a) in the circumferential direction of the sieve longitudinal axis (24), in particular on both sides, especially in the circumferential direction with respect to the sieve longitudinal axis (24). [11] Sieve device according to any one of the preceding claims, characterized by a sieve holder (21) receiving the sieve base body (20; 20a), with which the sieve device is fixed in the housing (14), in particular on its side covers (18). [12] Pneumatic conveying system for bulk materials with a. a powder dryer (2), b. a feed point (3) located downstream of the powder dryer (2), where the bulk material is fed into a conveying line (4) with pressurized conveying gas, c. a destination (6) connected to the conveying line (4) at which the bulk material is discharged from the conveying line (4), d. a sieve device (13) arranged along the conveying line (4) according to one of the preceding claims. [13] Pneumatic conveying system according to claim 12, characterized by , that a metering device (5) is arranged between the feed point (3) and the powder dryer (2).

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