EP3126066B1 - Sieve mechanism for unloading silo vehicles - Google Patents

Description

The invention relates to the technical field of milling, in particular the sieving of flour when unloading from silo vehicles.

In mills nowadays it is ensured with great effort and very reliably that the flour is free of particulate impurities in particular. The flour is then transported to further processing (e.g. a bakery) by silo vehicles. It is true that the hygiene of silo vehicles is generally not objectionable; however, particulate contaminants such as small stones are occasionally found. Basically, it is very much in the interest of the processor that no especially particulate impurities such as condensed flour lumps, broom hair residues, occasionally even stones or the like. get into its silo. For this reason, so-called control sieves are often arranged in the pneumatic conveyor line during unloading between the silo vehicle and the silo of the further processor. Such control sieves are stationed at the downstream processor, as they can practically not be carried on the silo vehicle. Control sieves based on various functional principles are known in principle. There is always the requirement to leave the flow velocity and thus the discharge time as unaffected as possible. One type of passive control sieve ensures this essentially by means of the largest possible sieve surface, which is arranged transversely to the main conveying direction. Such devices are very space-consuming. Other known control screens such as vibration screening machines can be designed to save space, but require additional energy.

Out GB 1 414 882 a control sieve is known in which additional air is blown in parallel to the actual conveying flow in front of a sieve arranged transversely to the main conveying direction. This additional air is fed from the same compressed air source as the conveying air for the conveying flow; additional energy is therefore not required. However, the filter performance and the reliability of such a device are in many cases insufficient. In addition, the size is too large for some requirements and the construction with a separate bypass line for the additional air is cumbersome.

The document FR 944 763 discloses a classifying device in which the material is fed through a nozzle, is deflected by a parabolic deflector and then passed through two cylindrical metal grids by means of further deflectors. The finer fraction leaves the device through two nozzles in the lower area, while the coarser fraction exits through a horizontal nozzle. This classifying device divides the particle flow into two separate particle flows.

From the U.S. 2,219,453 sieve devices with a cylindrical sieve are known. A body widening in the shape of a truncated cone is arranged within this sieve. Here, too, a particle flow is divided into two separate particle flows.

From the DE3443182A1 is a turbulence screen device which discloses a housing with a closed screen insert, the screen insert having a closed bottom.

It is therefore an object of the present invention to avoid the disadvantages of the prior art, in particular to provide a food sieve device for flour in a conveying stream, which can be operated without its own separate energy supply, is easy to use and ensures a high conveying capacity.

This object is achieved by the subjects of the independent claims. Advantageous refinements are given in the dependent claims.

• ein Gehäuse mit einem Gehäuseeinlauf und einem Gehäuseauslauf;
• einen geschlossenen Siebeinsatz, der im Wesentlichen innerhalb des Gehäuses derart angeordnet ist, dass
  1. i. ein Raumbereich zwischen der Innenwand des Gehäuses und der Aussenwand des Siebeinsatzes gebildet ist;
  2. ii. Siebelemente des Siebeinsatzes im Wesentlichen parallel zur Hauptförderrichtung angeordnet sind;
• eine Schlauchkupplung am Gehäuseeinlauf und/oder am Gehäuseauslauf,

wobei die Lebensmittelsiebvorrichtung derart ausgebildet ist, dass das Mehl in einem Förderstrom aus Luft antreibbar ist.A first aspect of the present invention relates to a passive food screening device for flour in a conveying stream, according to the subject matter of claim 1, comprising

• a housing with a housing inlet and a housing outlet;
• a closed sieve insert which is arranged essentially within the housing such that
  1. i. a space is formed between the inner wall of the housing and the outer wall of the strainer insert;
  2. ii. Sieve elements of the sieve insert are arranged essentially parallel to the main conveying direction;
• a hose coupling at the housing inlet and / or at the housing outlet,

wherein the food sieve device is designed such that the flour can be driven in a conveying flow of air.

The screening device according to the invention is designed as a passive screening device. So it does not contain any actively driven components, as is the case with the in EP 1 344 576 A1 , WO 91/05616 A1 and U.S. 5,427,250 disclosed devices is the case. By dispensing with actively driven components, the screening device is particularly low-maintenance.

Food which is sieved with the food sieve device according to the invention are bulk goods. These are typically grain, grain milling products and end grain products from milling (especially from common wheat, durum, rye, corn and / or barley) or from specialty milling (peeling products or milling products from soy, buckwheat, Barley, spelled, millet / sorghum, pseudocereal and / or legumes); but also feed for farm animals and pets, fish and crustaceans; Oil seeds and their processed products; Malting and grist products; Sugar, salt, cocoa beans, nuts and coffee beans and their processed products.

The bulk material, which is preferably flour, is introduced into the sieve device via the housing inlet. This is done pneumatically in a manner known per se. The bulk material leaves the screening device via the housing outlet. A closed sieve insert is arranged between the housing inlet and the housing outlet, which is essentially located inside the housing. Parts of the sieve insert which are not used for actual sieving can also be arranged outside the housing. This can be useful, for example, in order to ensure that the sieve insert can be removed in a particularly simple manner, in that part of the sieve insert protrudes outwards or at least reaches as far as the outer area of the sieve device and can thus be easily removed after a corresponding unlocking, for example . for cleaning purposes. According to the invention, the sieve insert is arranged in the housing in such a way that a spatial area is formed between the inner wall of the housing and the outer wall of the sieve insert (which is at least partially formed by sieve elements). The bulk material enters this space after it has passed the sieve element (s).

The sieve insert is designed as a closed sieve insert (in contrast to the ones in, for example WO 87/00454 A1 , FR 944 763 , WO 91/05616 A1 or U.S. 2,219,453 revealed seven). This is understood here and in the following to mean that the sieve insert has an inlet for the flour and any contained therein Contains contaminants, but does not contain an outlet for contaminants retained by the strainer. In the context of the invention, a closed sieve insert is understood to be a sieve insert as described below which has sieve surfaces in the bottom area through which only the flour can escape, but not also impurities.

The sieve elements are arranged essentially parallel to the main conveying direction.

In the context of the invention, “main conveying direction” is understood to mean in particular the longitudinal axis of the housing.

In the context of the invention, “essentially parallel” is also understood to include a deviation of ± 45 °. However, the deviation is advantageously less than ± 20 °, particularly advantageously less than ± 15 °.

Furthermore, the sieve device according to the invention is designed in such a way that the flour can be driven in a conveying flow of air. The flour does not fall just because of its gravity, as it does, for example, according to WO 87/00454 A1 or U.S. 5,427,250 treated screenings is the case. The flour is particularly preferably driven in a conveying stream of compressed air. This can significantly increase throughput. In this way, too, the screening device according to the invention can fulfill its function in any orientation - that is, independently of gravity.

The sieve surface formed by the entirety of the sieve elements is particularly advantageously aligned at least 80% essentially parallel to the main conveying direction, advantageously at least 90%, particularly advantageously at least 95%.

Because the majority of the sieve element (s) are arranged essentially parallel to the main conveying direction, a very high sieving capacity can be achieved with the least possible space requirement and the flow velocity can be essentially left unaffected: When unloading a silo vehicle, hoses and pipelines are connected in any case to establish a fluid connection. A sieve device according to the invention can be easily integrated into this fluid connection. This is done via hose couplings known per se, which are provided on the housing inlet, on the housing outlet or both on the housing inlet and on the housing outlet. Both silo vehicles and connection devices to silos are already equipped with such hose couplings. Sieve devices according to the invention can thus be integrated very easily into a fluid connection between the silo vehicle and the silo. Preferred hose couplings within the scope of the invention are plug-in couplings and those screw couplings which can be fixed with as few rotations as possible, in particular with less than one complete rotation. Hose couplings which can be used very particularly preferably within the scope of the invention are fire brigade couplings, such as, for example, the so-called Storz couplings, which function on the principle of a bayonet lock. Here, lugs of one half-coupling engage in corresponding contours of the counter-coupling and are locked there by turning the two half-couplings. The hose couplings are particularly preferably formed from aluminum, in particular from forged or pressed aluminum. Hose couplings made of brass, gunmetal or stainless steel are also possible. Sealing materials for use in such hose couplings are known in food technology, for example polyurethane or polytetrafluoroethylene.

A screening device according to the invention can, for example, be connected to a complementary fixed coupling existing on the silo, or directly to the outlet of the silo vehicle, or between two elements of the fluid connection to be established between silo vehicle and silo by means of hose elements and / or pipe elements.

It has been found that typical unloading capacities of 30 t / h (at a pneumatic pressure of approx. 1.5 to 2.0 bar) can still be achieved with the screening devices according to the invention. Nevertheless, sieving devices according to the invention can easily be implemented with a weight of less than 25 kg, since no separately driven parts such as vibrating floors or the like are included.

The sieve device can have an overall length in the range from 5 cm to 1 m, preferably from 7.5 cm to 60 cm. The inner wall of the housing can have a diameter (or another comparable average dimension, for example a side width in the case of square designs) which is in the range from 11 cm to 35 cm, preferably from 13 cm to 25 cm, particularly preferably from 15 cm to 20 cm . The ring width of the ring space / space area can be in the range from 10 mm to 50 mm. The inside diameter of the sieve insert can be in the range from 10 cm to 30 cm, preferably in the range from 13 cm to 17 cm.

Sieve devices according to the invention can also be built very slim because it is possible to dispense with the removal of the sieve rejects. Typically only (very) small amounts of impurities are present at this stage in the production chain. Impurities retained by the sieve device can thus be periodically disposed of simply by removing and emptying the sieve insert.

The mesh size of the screen elements is typically 3 mm or less, in particular between 1 mm and 3 mm, or between 1.5 mm and 2.5 mm.

In preferred embodiments of the sieve device, the space area between the inner wall of the housing and the outer wall of the sieve insert is designed essentially in the shape of a cylinder jacket, a cone jacket or a truncated cone jacket. Such geometries enable particularly slim designs and ensure that the sieve insert can be easily removed, as will be explained below.

Further preferably, external fittings for the flow line are arranged in the space between the inner wall of the housing and the outer wall of the strainer insert. Such internals support the conveying capacity, prevent deposits and, in particularly advantageous configurations, also ensure turbulence, which prevents the accumulation of bulk material in front of the sieve. It is very particularly preferable for such external internals to be of helical design, either as a single helix or as helical elements that are not connected to one another. More preferably, such helical, external internals are designed in such a way that the helix or helical elements pass through the entire spatial area at least once.

It has also been found to be particularly advantageous if one or more internal fittings for the flow line are arranged within the sieve insert. In this way, even before the bulk material passes through the sieve element (s), such a turbulent flow can be achieved that accumulations of bulk material in front of the sieve elements can be reliably prevented. Such internal internals are advantageous in Arranged in a substantially conical or frustoconical shape on an axis along the main conveying direction, the lateral surfaces of the built-in / built-in components being aligned in the main conveying direction in such a way that they cause a deflection in the direction of the screen elements. If several such internals are provided along the main conveying direction, they are preferably designed in such a way that their base area is larger, the further downstream they are arranged.

It has also proven to be advantageous that at least one further internal installation, in particular a helical installation, is arranged upstream of the conical or frustoconical internal installation (s) as described above. This further internal installation, in particular the helical installation, is preferably arranged within the sieve insert. Particularly advantageously, a conical internal installation is provided reaching up to the downstream end of the sieve insert, with the further, in particular helical, internal installation upstream being designed to approach the conical internal installation.

• in seinem stromaufwärtigen Endbereich kegelförmig ausgebildet ist, wobei eine Kegelspitze des/der inneren Einbaus/Einbauten stromaufwärts weist; und
• in seinem stromabwärtigen Bereich kegelförmig oder kegelstumpfförmig ausgebildet ist, wobei eine Kegelspitze des/der im stromabwärtigen Bereich kegelförmig ausgebildeten Einbaus/Einbauten bzw. eine Deckfläche des/der im stromabwärtigen Bereich kegelstumpfförmig ausgebildeten Einbaus/Einbauten stromabwärts weist.

Those screening devices have also proven to be advantageous which have at least one further internal installation upstream of the conical or frustoconical internal installation (s)

• is conical in its upstream end region, a cone tip of the inner installation (s) pointing upstream; and
• is conical or frustoconical in its downstream area, with a cone tip of the built-in / built-in (s) configured conically in the downstream area or a top surface of the in downstream area of frustoconical internals / internals has downstream.

The upstream-pointing cone tip provided in the upstream end region causes the bulk material to be deflected without the formation of deposits. The associated turbulence effectively prevents the bulk material from being deposited in front of the sieve elements. The installation is directed downstream in its downstream area with the cone tip or the top surface, whereby the flow can be brought together again to a smaller cross section.

In examples which do not form part of the invention, it has proven to be advantageous that an internal installation is essentially conical and extends down into the downstream end area of the sieve insert, the diameter of the base area of the conical internal installation at the downstream end region of the sieve insert essentially corresponds to the diameter of the sieve insert. Here, the conical inner installation can extend essentially over the entire length of the sieve insert.

Sieving devices according to the invention do not require any additional energy supply (apart from the flow energy of the pneumatic conveying flow) to effect the sieving. In the context of the invention, however, movably mounted elements can be used which can be set in motion by the bulk material flowing through the sieve device. This is particularly preferably a rotational movement. In principle, all the internals described above can be movably mounted in such a way that they can be set in motion, in particular in rotation, due to a conveying flow. Spiral internals do not require any further modification in their surface structure; only in the case of the conical or frustoconical ones described Built-in surface structures are to be provided that are suitable for achieving a torque (e.g. helical ribs or the like).

As already described above, the sieve insert can particularly advantageously be removed from the housing. This makes cleaning much easier. More preferably, the housing has a lockable cover, in particular a removable cover or a hinged or swivel cover, in the area of the housing inlet, which enables the housing to be opened in such a way that the sieve insert can be removed from the housing. Incorrect manipulations during operation, which could lead to an unintentional separation of the sieve insert from the housing, are essentially excluded, while still being very easy to use.

It has been shown that a sieve device according to the invention essentially does not have to have a downstream floor area which is arranged essentially orthogonally to the main conveying direction and is not equipped with sieve elements. It was found that a closed floor area for generating sufficient turbulence to prevent the accumulation of bulk material in front of the sieve elements is unnecessary. Rather, this floor area is also particularly advantageously available for equipping with sieve elements. The large majority of the screen surface is, however, formed essentially parallel to the main flow direction, as explained above.

In advantageous embodiments, the housing inlet can be arranged tangentially. This causes an immediate redirection of the flow, which means shortly after the inlet of the housing an advantageous turbulence can be generated before the bulk material reaches the sieve elements.

The housing has at least one viewing window through which the flour flowing through the sieve insert can be seen. In this way, the correct function of the sieve device can be checked, and it can in particular be determined when the sieve insert needs to be cleaned or replaced.

Another aspect of the invention relates to the use of a food sieve device described above as a sieve device that can be carried along on a silo vehicle. Due to the slim design, the screening device can easily be carried by a silo vehicle, as is otherwise common for hose elements. It is therefore no longer necessary for a processor to have a control screen available at the unloading location. The sieve device according to the invention can either be stored in storage compartments on the vehicle, like conventional hose elements. The screening device is then removed for use from a storage compartment and integrated into the fluid connection from the silo vehicle to the silo. Alternatively, it is also possible to permanently install the screening device on the silo vehicle. Due to the short overall length of typically less than approx. 1 m, this can be done, for example, in the rear area of a silo vehicle transversely to the direction of travel. Depending on requirements, the screening device according to the invention can then be brought into fluid connection on the inlet side via hose elements with the outlet of the silo vehicle and on the outlet side with the silo.

A further aspect of the invention accordingly relates to a silo vehicle according to the subject matter of claim 12, equipped with a food sieve device as described above.

• Einrichten einer Fluidverbindung zwischen einem Auslauf des Silofahrzeugs und dem Einlauf eines Silos derart, dass die Fluidverbindung eine Siebvorrichtung wie vorstehend beschrieben umfasst; und
• Pneumatische Förderung des Ladeguts aus dem Silofahrzeug durch die Siebvorrichtung in den Silo.

A final aspect of the invention relates to a method for unloading a silo vehicle, according to the subject matter of claim 13, comprising the steps:

• Establishing a fluid connection between an outlet of the silo vehicle and the inlet of a silo such that the fluid connection comprises a screening device as described above; and
• Pneumatic conveyance of the load from the silo vehicle through the screening device into the silo.

The pneumatic conveying is preferably carried out by means of compressed air, as this can significantly increase the throughput.

Figur 1a:

Schematische Darstellung einer ersten erfindungsgemässen Ausführungsform einer Siebvorrichtung im Querschnitt;

Figur 1b:

Dreidimensionale Schnittzeichnung der ersten erfindungsgemässen Ausführungsform einer Siebvorrichtung;

Figur 1c:

Dreidimensionale Gesamtansicht der ersten erfindungsgemässen Ausführungsform einer Siebvorrichtung;

Figur 1d:

Querschnitt des Siebeinsatzes der ersten erfindungsgemässen Ausführungsform einer Siebvorrichtung;

Figur 2a:

Schematische Darstellung einer nicht erfindungsgemässen Siebvorrichtung im Querschnitt;

Figur 2b:

Dreidimensionale Schnittzeichnung der nicht erfindungsgemässen Siebvorrichtung;

Figur 2c:

Dreidimensionale Gesamtansicht der nicht erfindungsgemässen Siebvorrichtung;

Figur 2d:

Dreidimensionale Gesamtansicht des Siebeinsatzes der nicht erfindungsgemässen Siebvorrichtung;

Figur 3a:

Schematische Darstellung einer weiteren, nicht erfindungsgemässen Siebvorrichtung im Querschnitt;

Figur 3b:

Dreidimensionale Schnittzeichnung der weiteren, nicht erfindungsgemässen Siebvorrichtung;

Figur 3c:

Dreidimensionale Gesamtansicht der weiteren, nicht erfindungsgemässen Siebvorrichtung;

Figur 3d:

Querschnitt des Siebeinsatzes der weiteren, nicht erfindungsgemässen Siebvorrichtung;

Figur 4a:

Schematische Darstellung einer weiteren, nicht erfindungsgemässen Siebvorrichtung im Querschnitt;

Figur 4b:

Dreidimensionale Schnittzeichnung der weiteren, nicht erfindungsgemässen Siebvorrichtung;

Figur 4c:

Dreidimensionale Gesamtansicht der weiteren, nicht erfindungsgemässen Siebvorrichtung;

Figur 4d:

Dreidimensionale Gesamtansicht des Siebeinsatzes der weiteren, nicht erfindungsgemässen

Figur 5a:

Siebvorrichtung; Eine weitere, nicht erfindungsgemässe siner Siebvorrichtung in einer perspektivischen Ansicht;

Figur 5b:

Die weitere, nicht erfindungsgemässe Siebvorrichtung in einer Seitenansicht;

Figur 5c:

Die weitere, nicht erfindungsgemässe Siebvorrichtung in einer seitlichen Schnittansicht.

The invention is explained in more detail below with reference to exemplary embodiments and figures, without the subject matter of the invention being restricted to the embodiments shown. Here show:

Figure 1a:

Schematic representation of a first embodiment according to the invention of a sieve device in cross section;

Figure 1b:

Three-dimensional sectional drawing of the first embodiment of a screening device according to the invention;

Figure 1c:

Three-dimensional overall view of the first embodiment of a screening device according to the invention;

Figure 1d:

Cross section of the sieve insert of the first embodiment of a sieve device according to the invention;

Figure 2a:

Schematic representation of a screening device not according to the invention in cross section;

Figure 2b:

Three-dimensional sectional drawing of the sieve device not according to the invention;

Figure 2c:

Three-dimensional overall view of the sieve device not according to the invention;

Figure 2d:

Three-dimensional overall view of the sieve insert of the sieve device not according to the invention;

Figure 3a:

Schematic representation of a further sieve device not according to the invention in cross section;

Figure 3b:

Three-dimensional sectional drawing of the further sieve device not according to the invention;

Figure 3c:

Three-dimensional overall view of the further screening device not according to the invention;

Figure 3d:

Cross section of the sieve insert of the further sieve device not according to the invention;

Figure 4a:

Schematic representation of a further, not according to the invention Sieve device in cross section;

Figure 4b:

Three-dimensional sectional drawing of the further sieve device not according to the invention;

Figure 4c:

Three-dimensional overall view of the further screening device not according to the invention;

Figure 4d:

Three-dimensional overall view of the sieve insert of the other, not according to the invention

Figure 5a:

Sieve device; Another siner sieve device not according to the invention in a perspective view;

Figure 5b:

The further sieve device not according to the invention in a side view;

Figure 5c:

The further sieve device not according to the invention in a lateral sectional view.

Figures 1a / b show a first embodiment according to the invention of a screening device 1 in cross section ( Fig. 1a ) or in a three-dimensional sectional drawing ( Figure 1b ). The sieve device 1 has a housing 2 which is essentially cylindrical. A tangential housing inlet 3 is arranged in the upstream end region of the housing 2; A housing outlet 4 is arranged in the downstream end region of the housing 2. In this first embodiment, the housing 2 has end pieces in which the housing inlet 3 and housing outlet 4 are provided, these end pieces being mounted by screw connections. The sieve device also has a sieve insert 5 which has sieve elements 9. Between the inner wall 7 of the housing 2 and the outer wall 8 of the sieve insert 5 (or the sieve elements 9) there is a space 6 for the sieve passage educated. The sieve elements 9 are arranged essentially parallel to the main conveying direction F. In this embodiment, however, sieve elements 9 are also provided in the bottom area of the sieve insert, so that the sieve insert 5 is designed as a closed sieve insert 5 within the meaning of the present invention. However, these sieve elements 9 only make up a very small proportion of the total sieve area. In this embodiment, inner fittings 12 are arranged on an axis 13, which divert the flow onto the sieve elements. These inner fixtures 12 are here conical, the diameter of the base areas of the inner cone-shaped fixtures 12 being greater, the further downstream the respective inner fixture 12 is. The sieve elements can (in this embodiment as well as overall within the scope of the invention) be designed to be removable from the sieve insert, for example by means of clips or screw connections (not shown). Both the housing inlet 3 and the housing outlet 4 are provided with hose couplings 10, for example fire brigade couplings such as Storz couplings. In this way, a particularly easy-to-use and reliable fluid connection can be implemented.

Figure 1c shows the device according to Fig. 1a / b in a three-dimensional overall view. In this overall view, a hinged or swivel cover 14 can be clearly seen, which on the one hand ensures reliable holding of the sieve insert 5 in the housing 2, but on the other hand also ensures easy removal, for example for cleaning purposes. The design of the housing inlet 3 and the housing outlet 4 with hose couplings (here: Storz couplings) can be clearly seen.

In Fig. 1d the sieve insert 5 is shown separately. The sieve elements 9 are essentially on the entire effective outer surface of the sieve insert within the housing 2 (cf. Figure 1c ) arranged. A small portion of the screen surface is formed by a screen element 9 in the downstream end area of the screen insert 5.

The sieve device 1 according to Figures 1a-c with the sieve insert 5 according to Fig. 1d has an overall length of well under 1 m; the area of the housing between the screwed-on end pieces, in which the housing inlet 3 and housing outlet 4 are provided, has an overall length of 50 cm and an inner diameter of 20 cm. The inside diameter of the sieve insert 5 in the area of the sieve elements 9 is approximately 10 cm; In this exemplary embodiment, a spatial area 6 is thus formed which represents an annular space with a ring width of 5 cm. In the downstream area of the housing in the transition into the end piece, in which the housing outlet 4 is provided, a conical guide element is provided, which is directed with the cone tip upstream. The base of the cone is approx. 15 cm wide, so that there is an annular passage gap in the end piece with a ring width of 2.5 cm. The device has a total screen area of approx. 150,000 mm ² .

Figures 2a / b show a further screening device 1 not according to the invention in cross section ( Fig. 2a ) or in a three-dimensional sectional drawing ( Figure 2b ). The sieve device 1 has a housing 2 which is essentially cylindrical. In the upstream end region of the housing 2, an axial housing inlet 3 is arranged; A housing outlet 4 is arranged in the downstream end region of the housing 2. In this further, not according to the invention, the housing 2 has end pieces in which the housing inlet 3 and housing outlet 4 are provided, these end pieces being mounted by screw connections. The sieve device also has a sieve insert 5 which has sieve elements 9. Between the inner wall 7 of the housing 2 and the outer wall 8 of the sieve insert 5 (or the sieve elements 9), a space 6 is formed for the sieve passage. The screen elements are arranged essentially parallel to the main conveying direction F. Sieve elements in the bottom area of the sieve insert are not provided in this further sieve device not according to the invention. In this sieve device, an internal installation 12 is arranged along an axis 13, which is conical upstream and extends essentially over the entire effective length of the sieve insert 5. In the downstream end area of the sieve insert, the conical inner installation 12 extends up to the sieve elements. Further downstream, a likewise conical end region of the sieve insert is provided, which is directed downstream with the cone tip. In addition, external fixtures 11 are provided in the spatial area 6 in this screening device, which are continuously helical. Both the housing inlet 3 and the housing outlet 4 are provided with hose couplings 10, for example fire brigade couplings such as Storz couplings.

Figure 2c shows the device according to Fig. 2a / b in a three-dimensional overall view. In this overall view, the hinged or swivel cover 14 can be clearly seen, which on the one hand ensures reliable holding of the sieve insert 5 in the housing 2, but on the other hand also ensures easy removal, for example for cleaning purposes. The design of the housing inlet 3 and the housing outlet 4 with hose couplings (here: Storz couplings) can be clearly seen.

In Fig. 2d the sieve insert 5 is shown separately. The sieve elements 9 are essentially on the entire effective outer surface of the sieve insert within the housing 2 (cf. Figure 2c ) arranged. Only in a downstream end area of the sieve insert 5, there is a downstream cone as the bottom area which has no sieve elements 9.

The sieve device 1 according to Figures 2a-c with the sieve insert 5 according to Fig. 2d has an overall length of well under 1 m; the area of the housing between the screwed-on end pieces, in which the housing inlet 3 and housing outlet 4 are provided, has an overall length of 50 cm and an inner diameter of 20 cm. The inside diameter of the sieve insert 5 in the area of the sieve elements 9 is approximately 10 cm; In this exemplary embodiment, a spatial area 6 is thus formed which represents an annular space with a ring width of 5 cm. In the downstream area of the housing in the transition into the end piece, in which the housing outlet 4 is provided, a conical guide element is provided on the strainer insert 5, which is directed downstream with the cone tip. The device has a total screen area of approx. 150,000 mm ² . The helical external fixtures 11 have a pitch of 160 mm and extend over the entire ring width of 5 cm.

Figures 3a / b show a screening device 1 not according to the invention in cross section ( Fig. 3a ) or in a three-dimensional sectional drawing ( Figure 3b ). The sieve device 1 has a housing 2 which is essentially cylindrical. In the upstream end region of the housing 2, an axial housing inlet 3 is arranged; A housing outlet 4 is arranged in the downstream end region of the housing 2. In this screening device, the housing has 2 end pieces in which the housing inlet 3 and housing outlet 4 are provided, these end pieces being mounted by screw connections. The sieve device also has a sieve insert 5 which has sieve elements 9. Between the inner wall 7 of the housing 2 and the outer wall 8 of the sieve insert 5 (or the sieve elements 9) a space 6 is formed for the sieve passage. The screen elements are arranged essentially parallel to the main conveying direction F. Sieve elements in the bottom area of the sieve insert are not provided in this sieve device. In this embodiment, an internal installation 12 is arranged along an axis 13, which is designed to be continuously helical. In the downstream end area of the sieve insert, a further internal installation, which is conical in shape and with the cone tip pointing upstream, extends in the area of its base up to the sieve elements. In this screening device, no external fixtures are provided in the space area 6. Both the housing inlet 3 and the housing outlet 4 are provided with hose couplings 10, for example fire brigade couplings such as Storz couplings.

Figure 3c shows the device according to Fig. 3a / b in a three-dimensional overall view. In this overall view, the hinged or swivel cover 14 can be clearly seen, which on the one hand ensures reliable holding of the sieve insert 5 in the housing 2, but on the other hand also ensures easy removal, for example for cleaning purposes. The design of the housing inlet 3 and the housing outlet 4 with hose couplings (here: Storz couplings) can be clearly seen.

In Fig. 3d the sieve insert 5 is shown separately. The sieve elements 9 are essentially on the entire effective outer surface of the sieve insert within the housing 2 (cf. Figure 3c ) arranged. No sieve elements are arranged in the bottom surface, since in the downstream end area of the sieve insert a conical inner installation extends with its base area up to the sieve elements 9.

The sieve device 1 according to Figures 3a-c with the sieve insert 5 according to Fig. 3d has an overall length of well under 1 m; the area of the housing between the screwed-on end pieces, in which the housing inlet 3 and housing outlet 4 are provided, has an overall length of 50 cm and an internal diameter of 15 cm. The inside diameter of the sieve insert 5 in the area of the sieve elements 9 is approximately 10 cm; a spatial area 6 is thus formed in this screening device, which represents an annular space with a ring width of 2.5 cm. The device has a total screen area of approx. 157,000 mm ² . The helical inner internals 12 have a pitch of 178.5 mm and extend along the axis 13 essentially over the entire inner width of the set of sieves 5.

Figures 4a / b show a screening device 1 not according to the invention in cross section ( Figure 4a ) or in a three-dimensional sectional drawing ( Figure 4b ). The sieve device 1 has a housing 2 which is designed to taper substantially conically downstream. In the upstream end region of the housing 2, an axial housing inlet 3 is arranged; A housing outlet 4 is arranged in the downstream end region of the housing 2. In this screening device, the housing has 2 end pieces in which the housing inlet 3 and housing outlet 4 are provided, these end pieces being mounted by screw connections. The sieve device also has a sieve insert 5 which has sieve elements 9. Between the inner wall 7 of the housing 2 and the outer wall 8 of the sieve insert 5 (or the sieve elements 9), a space 6 is formed for the sieve passage. The sieve elements (or the outer wall 8 of the sieve insert) are inclined at an angle of approx. 11 ° to the main conveying direction F (in the context of the invention, however, still essentially parallel to the main conveying direction F). Sieve elements in the bottom area of the sieve insert are also not provided in this sieving device. In this screening device, an inner body is arranged along an imaginary longitudinal axis, which inner body essentially represents a truncated cone with a cover surface oriented downstream. In the upstream end region, a cone is formed directly adjacent to this truncated cone, the base areas of the frustoconical inner installation and the cone having the same diameter. In the downstream end area of the sieve insert, a further inner body, which is again designed in the shape of a truncated cone and with the top surface directed upstream, extends in the area of its base up to the sieve elements; the top surface of this truncated cone is directly adjacent to the top surface of the frustoconical inner body. In this screening device, no external fixtures are provided in the space area 6. However, an inner installation 12 is provided which helically surrounds that frustoconical inner body, which is directed with its top surface downstream. Both the housing inlet 3 and the housing outlet 4 are provided with hose couplings 10, for example fire brigade couplings such as Storz couplings.

Figure 4c shows the device according to Figure 4a / b in a three-dimensional overall view. In this overall view, the folding or swiveling device 14 can be clearly seen, which on the one hand ensures reliable holding of the sieve insert 5 in the housing 2, but on the other hand also ensures easy removal, for example for cleaning purposes. The design of the housing inlet 3 and the housing outlet 4 with hose couplings (here: Storz couplings) can be clearly seen.

In Figure 4d the sieve insert 5 is shown separately. The sieve elements 9 are essentially on the entire effective outer surface of the sieve insert within the housing 2 (cf. Figure 3c ) arranged. No sieve elements are arranged in the bottom surface, since in the downstream end area of the sieve insert a frustoconical inner body reaches up to the sieve elements 9 with its base.

The sieve device 1 according to Figures 4a-c with the sieve insert 5 according to Figure 4d has an overall length of well under 1 m; the area of the housing between the screwed-on end pieces, in which the housing inlet 3 and housing outlet 4 are provided, has an overall length of 50 cm and an inner diameter of between 23 cm in the upstream end area and 15 cm in the downstream end area. The inside diameter of the sieve insert 5 in the area of the sieve elements 9 is between approx. 20 cm in the upstream end area and 10 cm in the downstream end area; In this exemplary embodiment, a spatial area 6 is thus formed which represents an essentially frustoconical annular space with a ring width of between 1.5 cm and 2.5 cm. The device has a total screen area of approx. 215,000 mm ² .

The ones in the Figures 5a to 5c The sieve device 1 shown, not according to the invention, has a cylindrical housing 2. In the upstream end region of the housing 2, both an axial housing inlet 3 and a removable cover 14 are arranged; A housing outlet 4 is arranged in the downstream end region of the housing 2. The sieve device 1 also has a sieve insert 5. Between the inner wall 7 of the housing 2 and an outer wall 8 of the sieve insert 5, a space 6 is formed for the sieve passage. Both the housing inlet 3 and the housing outlet 4 are provided with hose couplings 10 not shown in detail here, for example fire brigade couplings such as Storz couplings. The housing 2 has four viewing windows 20 distributed over the circumference, through which the the sieve insert 5 flowing flour is visible. The screening device 1 according to Figures 5a to 5c has an inner wall diameter of 18.4 cm and a length of 40 cm to 50 cm.

All of the embodiments described above are designed as passive screening devices. They do not contain any actively driven components, so that they are particularly low-maintenance. In addition, in all the exemplary embodiments described above, the flour is driven in a conveying stream of compressed air. The flour does not fall due to gravity alone, which can significantly increase throughput.

Claims (13)

1. Passive foodstuff screen device (1) for unloading flour in a conveying flow from a silo vehicle, wherein the foodstuff screen device (1) comprises:

   - a housing (2) having a housing inlet (3) and a housing outlet (4), and at least one viewing glass (20) through which the flour flowing through a closed screen insert (5) is visible;

   - the closed screen insert (5) which is disposed so as to be substantially within the housing (2) in such a manner that

   i. a spatial region (6) is formed between the internal wall (7) of the housing (2) and the external wall (8) of the screen insert (5) ;

   ii. at least one screen element (9) of the screen insert (5) is disposed so as to be substantially parallel with the main conveying direction (F);

   - a hose coupling (10) on the housing inlet (3) and/or on the housing outlet (4);

   wherein the foodstuff screen device (1) is configured in such a manner that the flour is capable of being driven in a conveying flow of air, and wherein the base region of the screen insert that is disposed so as to be orthogonal to the main conveying direction (F) is equipped with at least one screen element; and
   wherein the main conveying direction is understood to be the longitudinal axis of the housing.
2. Screen device (1) according to Claim 1, characterized in that the hose coupling (10) is configured as a firefighting coupling (10), in particular as a Storz coupling (10).
3. Screen device (1) according to one of the preceding claims, characterized in that said screen device (1) has a weight of below 25 kg.
4. Screen device (1) according to one of the preceding claims, characterized in that said screen device (1) has a construction length in the range from 5 cm to 1 m, preferably from 7.5 cm to 60 cm.
5. Screen device (1) according to one of the preceding claims, characterized in that the internal wall (7) of the housing has a diameter that is in the range from 11 cm to 35 cm, preferably from 13 cm to 25 cm, particularly preferably from 15 cm to 20 cm.
6. Screen device (1) according to one of the preceding claims, characterized in that the spatial region (6) is configured so as to be substantially cylinder-barrel shaped, cone-shell shaped, or truncated cone-shell shaped.
7. Screen device (1) according to one of the preceding claims, characterized in that external installations (11) for flow direction, which in particular are helically configured, are disposed in the spatial region (6).
8. Screen device (1) according to one of the preceding claims, characterized in that one internal installation or a plurality of internal installations (12) for flow direction is/are disposed within the screen insert (5).
9. Screen device (1) according to Claim 8, characterized in that one internal installation or a plurality of internal installations (12) is/are disposed in a substantially cone-shaped or truncated cone-shaped manner on an axle (13) along the main conveying direction (F), wherein shell surface(s) of the internal installation(s) (12) is/are aligned in the main conveying direction (F) in such a manner that said shell surface(s) causes/cause deflection in the direction of the at least one screen element (9).
10. Screen device (1) according to one of the preceding claims, characterized in that the housing (2), in particular in the region of the housing inlet (3), has a lockable cover, in particular a removable cover or a flap or pivot cover (14), which enables the housing (2) to be opened in such a manner that the screen insert (5) is retrievable from the housing (2).
11. Screen device (1) according to one of the preceding claims, characterized in that the housing inlet (3) is disposed in a tangential manner.
12. Silo vehicle equipped with a foodstuff screen device (1) according to one of Claims 1 to 11.
13. Method for unloading a silo vehicle in particular according to Claim 12, the method comprising the following steps:

    - establishing a fluid connection between an outlet of the silo vehicle and the inlet of a silo in such a manner that the fluid connection comprises a foodstuff screen device (1) according to one of Claims 1 to 11; and

    - pneumatically conveying the payload from the silo vehicle through the screen device (1) into the silo.

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