Sieving machine with insertable sieve tray elements

Abstract

The invention relates to a sieving machine having at least one sieve deck (5), that has a plurality of insertable sieve tray elements (8) that are attached to cross-beams (9) of the sieving machine by means of a mounting system (10), wherein the mounting system (10) comprises longitudinal beams (11), which are mounted on the cross-beams (9), and a plurality of support slats (13), which extend along the longitudinal beams (11) and with which the sieve tray elements (8) engage. The sieving machine is characterised in that the support slats (13) have a U-shaped cross-section, and are fitted over the longitudinal beams (11), wherein hooks (112) are formed on the longitudinal beams (11), which engage in the support slats (13), thereby fastening the support slats (13) to the longitudinal beams (11) in a form-fitting manner.

Description

[0001] Screening machine with insertable sieve bottom elements

[0002] The invention relates to a screening machine, in particular a vibrating screening machine, with at least one screening deck having a plurality of insertable screening base elements which are fastened to crossbeams of the screening machine by means of a mounting system, wherein the mounting system comprises longitudinal beams which are mounted on the crossbeams, and a plurality of support strips which run along the longitudinal beams and with which the screening base elements are reinforced.

[0003] Vibrating screening machines, also called “vibrating screening machines”, are used for classification, pre-separation, dewatering or screening for foreign matter.

[0004] Particularly in screening machines with a large screen deck, the area of ​​which can exceed several square meters, a screen base is often used which consists of a large number of plug-in screen base elements. For example, a mounting system is known on the market in which a number of parallel longitudinal beams are mounted on crossbeams of a screen box of the screening machine. The longitudinal beams used are, for example, steel profiles with a rectangular cross-section which have a longitudinal groove on their upper side, so that ultimately a roughly C-shaped profile is created. A plastic strip which has a mushroom-shaped profile towards the top is inserted into the groove. Screen base elements which are typically made of a plastic whose surface has openings for the passage of the screened material are placed on top of this profile.The sieve tray elements are pressed onto the mushroom-shaped profile of the plastic strips using appropriate holders, thereby securing them. Sieving can occur directly through the openings of the sieve tray units. Alternatively, an additional sieve lining can be applied, such as a wire mesh that is attached and stretched to a surrounding frame. Sieve tray elements consisting of a plastic tube with a cast-in wire mesh are also known.

[0005] This system has generally been established but does have some shortcomings. The plastic strips are usually about the same length as a screen element, i.e. around one meter. The plastic strips can be damaged when the screen elements are being fitted and, in particular, when they are being removed for inspection or replacement. Even if only a short section is damaged, the entire strip must be replaced, which is not only labor-intensive but also unnecessarily expensive. A further disadvantage is that the plastic strips can only be inserted into the groove of the longitudinal beams with considerable force - usually by tapping them in with a hammer. This is generally strenuous work and poses a risk of injury, especially on a lower screen deck.

[0006] In addition, there is a risk that gaps remain between two adjacent plastic strips, through which the screening material can get into the metal strips with the rectangular profile, which are used as longitudinal supports, and abrasively destroy the strips from the inside during the movement of the vibrating screen.

[0007] It is therefore an object of the present invention to provide a screening machine of the type mentioned at the outset in which assembly of the vibrating screening elements is improved in such a way that replacement of components is easier and, if necessary, less material-intensive and that the components used are better protected against abrasive wear by the screening material.

[0008] This problem is solved by a screening machine having the features of the independent claim. Advantageous embodiments and further developments are the subject of the dependent claims.

[0009] A screening machine according to the invention of the type mentioned at the outset is characterized in that the support bars have a U-shaped cross-section and are slipped over the longitudinal beams, wherein hooks are formed on the longitudinal beams which engage in the support bars, whereby the support bars are fastened to the longitudinal beams in a form-fitting manner.

[0010] Because the support bars have a U-shaped cross-section, they can be slipped over the longitudinal beams, thus protecting them from abrasion by the screening material. Unlike pressing the support bars into the longitudinal beams, for example, the hook-shaped design allows for simple and non-destructive disassembly, thus making it easy to replace the support bars if they become damaged.

[0011] For the locking and / or clamping fastening of the sieve base elements, the support strips have a continuous or interrupted locking profile at the top, for example a mushroom head profile.

[0012] In an advantageous embodiment of the screening machine, the longitudinal beams are made of sheet metal, with the hooks cut out of the sheet metal at an upper edge of the longitudinal beams. The hooks can thus be easily formed integrally with the longitudinal beams. Manufacturing from sheet metal, e.g., using a punching or laser cutting process, is also cost-effective. For stability reasons, the longitudinal beams can be made of two or more parallel sheets or can vary in height.

[0013] Preferably, a plurality of hooks are provided on a longitudinal member, arranged one behind the other at regular intervals along the longitudinal direction of the longitudinal members. This creates a correspondingly large number of force transmission points between a support bar and a longitudinal member, allowing correspondingly large forces to be transmitted evenly. The resulting connection between the two elements is resilient, preventing material fatigue, which could otherwise occur due to excessively large point-acting forces.

[0014] In a further advantageous embodiment of the screening machine, the longitudinal beams have a length that is roughly the same as the distance between two crossbeams of the screening machine, with the longitudinal beams resting on one of the crossbeams in a central section. Such longitudinal beams that do not run the entire length of the screen box are easier to manufacture, transport, and replace. The distance between two crossbeams can be, for example, in the region of one meter, so that the longitudinal beams also have approximately this length. Alternatively, it is also possible to use longer longitudinal beams, possibly up to the length of the entire screening deck, which can be several meters. This can be advantageous for cost reasons.

[0015] In a further advantageous embodiment of the screening machine, the support bars have side walls with which they rest against the outer sides of the longitudinal beams, with projections formed on the inner sides of the side walls that engage with the hooks. To mount the support bar on the longitudinal beam, the support bar is placed so that the projections are located between the hooks of the longitudinal beam. In this position, the support bar is pressed downward until it rests on the inside of the upper side of the hooks. The support bar is then moved along the longitudinal beam against the opening direction of the hooks, with the projections engaging with the undercuts of the hooks.

[0016] The support strips are preferably made of plastic and have a length of less than 30 centimeters (cm), which allows them to be easily and cost-effectively manufactured as molded parts using a plastic injection molding process. Because the support strips are relatively short, damaged sections can be easily replaced with minimal material loss.

[0017] In a further advantageous embodiment of the screening machine, a wedge element is connected to at least one of the support bars. The wedge element is also placed on one of the longitudinal beams and engages with a vertically aligned wedge between two hooks. Support bars and wedge elements preferably alternate along a longitudinal beam. The wedge element prevents the projections of the support bars from moving out of the undercuts of the hooks. The support bar is thus wedged by the wedge element in such a way that it is fixed to the longitudinal beam in all spatial directions. The subsequently mounted screen base units then prevent the wedge elements from moving upwards, so that with the screen base unit in place, the entire assembly system is positively fastened to the longitudinal beams. For assembly, the support bars are preferably moved in the direction of material flow on the screen base.In this way, the forces that the wedge element has to absorb for securing purposes are low.

[0018] In a further advantageous embodiment of the screening machine, an overlapping strip is formed on the side walls of the support bars and, if applicable, also on the side walls of the wedge elements, which covers a gap to an adjacent support bar or, if applicable, an adjacent wedge element. This prevents screening material or water from getting between the adjacent support bars or wedge elements and the longitudinal beams in the transition area, thereby providing the best possible protection for the longitudinal beams. In a further advantageous embodiment of the screening machine, the longitudinal beams are attached to the crossbeams by means of adhesive. The adhesive is preferably applied to the side walls of the crossbeams.

[0019] Adhesive bonding is advantageous because it does not weaken the crossbeam. Furthermore, if the mounting profiles are attached solely with rivets or screws, micro-movements induced by the screen movement can occur between the crossbeams and the mounting profiles. This can lead to long-term damage to the usual corrosion protection layer and thus to corrosion at the attachment points. These adverse micro-movements are effectively prevented by adhesive bonding. By bonding the mounting profiles to the side walls of the crossbeams, only shear forces act on the bonded surface during screening machine operation, thus enabling secure attachment of the longitudinal beams with the adhesive bond.

[0020] The described mounting system can preferably be used with screening machines that are designed as vibrating screening machines

[0021] The invention is explained in more detail below using exemplary embodiments and figures. The figures show:

[0022] Fig. 1 a shows a vibrating screening machine in a schematic isometric overall view;

[0023] Fig. 1 b is an enlarged section of Fig. 1 a;

[0024] Fig. 2 is an isometric detailed view of a section of a vibrating screening machine with the screen bottom dismantled and the screen bottom mounting system partially dismantled;

[0025] Fig. 3 is a detailed view of a section of Fig. 2 from a different viewing direction;

[0026] Fig. 4 is an isometric detailed view of a section of a vibrating screening machine with a dismantled screen base and a partially dismantled mounting system for the screen base in another embodiment; Fig. 5 is a detailed view of a section of Fig. 4 from a different perspective;

[0027] Fig. 6 is a schematic sectional view through a section of a mounting system for a sieve bottom;

[0028] Fig. 7a, b each show an isometric view of two components of the assembly system according to Fig. 6;

[0029] Fig. 8a-c different representations of the components from figures 7a, b in a joined state.

[0030] In Fig. 1a, an embodiment of a vibrating screening machine is shown in an isometric overview view.

[0031] The vibrating screen is mounted on a frame-like support structure (not shown here), which in turn is mounted on a base or substructure (also not shown here). The support structure is tilted relative to the horizontal in the conventional manner to facilitate material transport through the vibrating screen.

[0032] The vibrating screening machine itself comprises a screen box 1, which has two brackets 2 on both sides. These brackets 2 support the screen box 1 on spring assemblies 3. In other configurations of the vibrating screening machine, the number of brackets 2 and spring assemblies 3 can be greater than two on each side. The spring assemblies 3 are formed here, for example, by two spring-loaded rubber dampers each. In addition to the rubber dampers shown here, metal springs can also be used additionally or alternatively.

[0033] During operation, the screen box 1 as a whole is subjected to circular, elliptical or linear oscillations in the usual way, in this embodiment by means of an eccentric drive 4. Other drives are also possible. The screen box 1 is limited at the top by a screen deck 5. During operation of the screening machine, material to be screened is fed onto this screen deck 5 in a feed area 6 and leaves the screening machine at the opposite end in a discharge area 7 or falls downwards out of the screen box 1 after being screened. The screening machine shown here has two screen decks arranged one above the other, with only the discharge area of ​​the lower one being visible. In alternative embodiments, the screen box 1 can have just one screen deck or more than two screen decks can be arranged one above the other, which enable gradually finer screening.

[0034] The screen deck 5 has a screen base, which in this case consists of a plurality of screen base units 8 arranged side by side and one behind the other. These screen base units 8 have openings through which the screening takes place. The use of the plurality of screen base units 8 enables easier replacement of a damaged or worn area of ​​the screen base, in contrast to a continuous screen base, e.g., formed from a perforated plate or a grid, which is one-piece or composed of only a few parts.

[0035] In a central area of ​​the screen deck 5, some of the screen tray units 8 have been removed. This area of ​​the screening machine is shown in an enlarged view in Fig. 1b. The enlarged view shows a mounting system 10 that supports the screen tray units 8 along their long sides and to which the screen tray units 8 are attached. This mounting system 10 is explained in more detail in the following figures.

[0036] Fig. 2 shows a section of a screening machine, for example, the one shown in Figs. 1a and 1b. The same reference numerals identify the same or similarly functioning elements in all figures.

[0037] Sieve tray units (see reference numeral 8 in Fig. 1 a, b) are not mounted in the section shown in Fig. 2. This allows a view into the interior of the sieve box 1 and the mounting system 10 for such sieve tray units. The mounting system is not fully assembled in all areas to better illustrate its various components.

[0038] The mounting system 10 comprises longitudinal beams 11, which are mounted with a U-shaped cutout on a crossbeam 9 of the screen box 1. The longitudinal beams 11 are not continuous elements over the entire length of the screen box, but extend on both sides of the crossbeam 9 to approximately the middle of the distance to the next crossbeam 9.

[0039] The next of the crossbeams 9 is not directly visible in Fig. 2. It is located under a cover 91, which is also present in sections on the visible crossbeam 9. The cover 91 is preferably made of an impact- and abrasion-resistant material, such as a plastic, and is placed section by section over the crossbeams 9 to prevent damage to the crossbeam 9 from falling screenings.

[0040] Because the longitudinal beams 11 do not extend along the entire screen box 1, but rather only cover the area surrounding a crossbeam 9, they are easier to manufacture, transport, and replace. The longitudinal beams 11 are attached to the crossbeams 9 with a fastener 12. In the example shown, the longitudinal beams 11 are welded to the crossbeams 9 with weld seams 121.

[0041] In the example shown, each of the longitudinal members 11 is made of two parallel sheets. The sheets can be formed over the entire surface; for weight savings, openings can advantageously be provided, as can be seen in the example in Figures 2 and 3.

[0042] Plastic elements are placed on the longitudinal beams 11, which then support the sieve tray units (see reference numeral 8 in Figs. 1a, 1b). Support strips 13 and wedge elements 14 are used alternately. To secure the support strips 13 and wedge elements 14 to the longitudinal beams 11, an undercut profile is formed on their upper edge, specifically by hooks 112 in the example shown. The attachment of the support strips 13 and wedge elements 14 to the longitudinal beams 11 is explained in more detail below in connection with Figs. 6-8c.

[0043] Figs. 4 and 5 show an alternative mounting system 10 similar to that shown in Figs. 2 and 3. The basic structure is comparable to that of the exemplary embodiment shown in Figs. 2 and 3, to whose description reference is hereby made. What is different is, in particular, the fastening of the longitudinal beams 10 to the cross members 9.

[0044] In the example shown, the longitudinal members 11 are arched on their underside so that they extend like the arch of a bridge between the crossbeams 9. This achieves a high load-bearing capacity while minimizing weight. There is a recess in the area of ​​each crossbeam 9. Mounting profiles 122 are used as fastening elements 12; in the case shown, these have a T-shaped profile and are screwed to the longitudinal members 10. Two of the mounting profiles 122 rest on opposite side cheeks of a crossbeam 9. The lateral "pincer-like" arrangement of the mounting profiles 12 saves construction height compared to an arrangement on top of the crossbeam 9. The bonding is carried out, for example, using conventional structural adhesives for bonding thicker sheet metal constructions.

[0045] The mounting profiles 122 are glued to the side walls of the cross members 9 and, in this example, are additionally pre-tensioned and / or secured with rivets 123. The rivets 123 limit the expansion of the adhesive during short-term overloads and thus protect it from damage.

[0046] During operation of the screening machine, only acceleration forces acting perpendicular to the screening plane are transmitted between the crossbeams 9 and the longitudinal beams 11. Longitudinal forces are transmitted to the bonding surface through alternating compressive loads. By bonding the mounting profiles 122 to the side walls of the crossbeams 9, only shear forces act on the bonding surface during operation of the screening machine, which enables secure attachment of the longitudinal beams 11 with the bonding.

[0047] Adhesive bonding can be advantageous over other fastening methods because it does not weaken the crossbeam 9. This also results in easier replacement due to the detachability of the longitudinal strips 11. Weld seams, for example, can potentially influence the stability of the crossbeam due to their stress stress.

[0048] If the mounting profiles 112 are attached purely with rivets or screws, micro-movements induced by the sieve movement occur between the cross members 9 and the mounting profiles 112, which in the long term leads to damage to the usual corrosion protection layer and thus to corrosion at the attachment points. These detrimental micro-movements are effectively prevented by the adhesive bond.

[0049] 6-8c show a further exemplary embodiment of a mounting system 10 for mounting sieve deck units. The mounting system 10 shown in these figures differs in its geometry and details from that shown in Figs. 2 to 5. However, the basic structure is comparable in both and details of one or the other embodiment can be transferred to the other. Fig. 6 shows a sectional view in the longitudinal direction of the sieve deck through a section of the mounting system 10, which is placed on a crossbeam 9 and which comprises longitudinal members 11, support strips 13 and wedge elements 14. In this sectional view it can be seen that the longitudinal member 11 has a support surface 111 which, in this exemplary embodiment, is not provided with openings to reduce weight, but could be.Each of the longitudinal members 11 can be made of one or more sheets arranged parallel to one another and cut accordingly. The sheets can be punched or produced using a laser processing process.

[0050] Along the upper edge of the longitudinal members 11, the sheets are formed in the form of a plurality of undercut hooks 112. Corresponding grooves or undercuts 113 are formed beneath the hooks.

[0051] Figs. 7a and 7b show the two different support elements of the mounting system 10, which are placed on the longitudinal members 11—specifically, the support strip 13 in Fig. 7a and the wedge element 14 in Fig. 7b. Both components, the support strip 13 and the wedge element 14, are preferably made of plastic using a plastic injection molding process. The support strip 13 has a length in the range of approximately 15-30 cm, thus a length that can still be easily and inexpensively produced using a plastic injection molding process. The wedge element 14 has an overall length of a few centimeters and can therefore be manufactured just as easily and simply using an injection molding process.

[0052] The support bar 13 is essentially U-shaped, with two parallel side walls 131 and a base 133 connecting the two at their upper ends. The resulting U-shaped cross-section allows the support bar to be placed over the longitudinal beam, thus shielding it from abrasive screening material. Overlap bars 132 are formed at the edge of the side walls. These overlap bars cover the gaps at the transition to an adjacent element, another support bar 13, or a wedge element 14, and prevent screening material from getting between the support bar 13 or the wedge element 14 and the longitudinal beam 11.

[0053] A locking profile 134 is formed on top of the base 133, which is designed to be continuous in the longitudinal direction. Here, a mushroom-head profile is used as the locking profile 134, for example. In alternative embodiments, a differently shaped profile can be used as the locking profile 134 instead of the mushroom-head profile. Instead of a continuous profile, a plurality of profile elements, such as mushroom heads, can also be arranged on the top side of the base 133.

[0054] The wedge element 14 has a shorter overall length and essentially the same geometry as the support strip 13. The wedge element 14 is also U-shaped, with two parallel side cheeks 141 and a base 143 connecting at their upper sides. The side cheeks 141 are also provided with overlapping strips 142. A head profile 144, comparable to the locking profile 134, is formed centrally on the base. In addition, the wedge element 14 has a downward-facing wedge 145 in the upper area of ​​the side cheeks 141.

[0055] Fig. 8a shows an isometric overall view of an arrangement of support strips 13 and wedge elements 14 arranged one behind the other. Support strips 13 and wedge elements 14 alternate with each other, with the overlap strips 132 and 142 respectively overlapping the side walls 131, 141 of the adjacent element. Fig. 8b shows this overlap area in an enlarged view.

[0056] Finally, Fig. 8c shows a sectional view in a vertical longitudinal section through the arrangement of Fig. 8a. In this sectional view, it can be seen that a plurality of projections 135 are formed on the inside of the side cheeks 131 of the support strips 13.

[0057] To mount the support strip 13 on the longitudinal member 11, the support strip 13 is placed such that the projections 135 are located between the hooks 112 of the longitudinal member 11. In this position, the support strip 13 is pressed downward until its base 133 rests on the inside of the upper side of the hooks 112. The support strip 13 is then moved against the opening direction of the hooks on the longitudinal member 11 so that the projections 135 engage the undercuts 113 of the hooks 112, as can also be seen in Fig. 6.

[0058] A wedge element 14 is then inserted from above onto the longitudinal member 11 in front of a support strip 13 thus placed, with the wedge 145 resting against a rear edge on the non-opened side of a hook 112, thus preventing the support strip 13 from being pushed out toward the opening of the hook 112. The support strip 13 is thus wedged by the wedge element 15 so that it is fixed to the longitudinal member 11 in all spatial directions. A subsequent support strip 13 then adjoins the inserted wedge element 14.

[0059] After mounting the support strips 13 or wedge elements 14 on the longitudinal beams 11, the sieve bottom unit, see reference number 8 in Fig. 1a, 1b, is placed on the mounting system 10 and secured with the locking profile 134 of the support strips 13. The mounted sieve bottom unit prevents an upward movement of the wedge elements 14, so that with the sieve bottom unit in place, the entire mounting system 10 is positively secured.

[0060] The type of fastening of the support strips 13 and wedge elements 14 to the longitudinal beams 11 described in connection with Figs. 6-8c is also implemented in this way in the embodiments of Figs. 2-5.

[0061] List of reference symbols

[0062] 1 sieve box

[0063] 2 consoles

[0064] 3 spring pack

[0065] 4 eccentric drive

[0066] 5 screening decks

[0067] 6 Task area

[0068] 7 Drop-off area

[0069] 8 Sieve bottom unit

[0070] 9 Crossbeam

[0071] 91 Cover

[0072] 10 Mounting system

[0073] 11 longitudinal members

[0074] 111 Support surface

[0075] 112 hooks

[0076] 113 groove

[0077] 12 Fastening the longitudinal members

[0078] 121 Weld seam

[0079] 122 mounting profile

[0080] 123 rivet

[0081] 13 Support strip

[0082] 131 side panel

[0083] 132 Overlap strip

[0084] 133 Base

[0085] 134 locking profile

[0086] 135 lead

[0087] 14 wedge element

[0088] 141 side panel

[0089] 142 Overlap strip

[0090] 143 Base

[0091] 144 Head profile

[0092] 145 Wedge

Claims

Claims 1. Screening machine with at least one screen deck (5) having a plurality of insertable screen bottom elements (8) which are attached to crossbeams (9) of the screening machine by means of a mounting system (10), wherein the mounting system (10) comprises longitudinal beams (11) which are mounted on the crossbeams (9), and a plurality of support strips (13) which run along the longitudinal beams (11) and with which the screen bottom elements (8) are secured, characterized in that the support strips (13) have a U-shaped cross-section and are placed over the longitudinal beams (11), wherein hooks (112) are formed on the longitudinal beams (11) which engage in the support strips (13), whereby the support strips (13) are positively locked to the longitudinal beams (11).

2. Screening machine according to claim 1, wherein the longitudinal beams (11) are made from a sheet metal, wherein the hooks (112) are cut free from the sheet metal at an upper edge of the longitudinal beams.

3. Screening machine according to claim 2, wherein the longitudinal beams (11) are made of two or more sheets arranged parallel to each other.

4. Sieving machine according to one of claims 1 to 3, in which the hooks (112) are arranged one behind the other at regular intervals in the longitudinal direction of the longitudinal beams.

5. Screening machine according to one of claims 1 to 4, wherein the longitudinal beams have a length which is in the range of the distance between two crossbeams (9) of the screening machine, wherein the longitudinal beams (11) each rest on one of the crossbeams (9) in a central section.

6. Screening machine according to one of claims 1 to 5, wherein the support strips (13) have side cheeks (131) with which they abut the outer sides of the longitudinal beams (11), wherein projections (135) are formed on the inner sides of the side cheeks (131) which engage in the hooks (112).

7. Sieving machine according to one of claims 1 to 6, wherein the support strips (13) are made of plastic. A screening machine according to claim 7, wherein the support strips (13) have a length in the range of 10 to 100 cm, preferably 15 to 50 cm, and particularly less than 30 cm, and are manufactured as molded parts using a plastic injection molding process. A screening machine according to any one of claims 1 to 8, wherein a wedge element (14) is subsequently mounted on one of the longitudinal beams (11) following at least one of the support strips (13), the wedge element engaging with a vertically oriented wedge (145) between two hooks (112). A screening machine according to claim 9, wherein support strips (13) and wedge elements (14) alternate. A screening machine according to any one of claims 6 to 10, wherein an overlap strip (132) is formed on each of the side walls (131) of the support strips (13), which covers a gap to an adjacent support strip (13) or, optionally, an adjacent wedge element (14).A screening machine according to any one of claims 1 to 11, wherein the support rails (13) have a continuous or interrupted locking profile (134) towards the top, in particular a mushroom-head profile. A screening machine according to any one of claims 1 to 12, wherein the longitudinal beams (11) are attached to the crossbeams (9) by means of an adhesive bond. A screening machine according to claim 13, wherein the adhesive bond is applied to the side walls of the crossbeams (9). A screening machine according to any one of claims 1 to 14, designed as a vibrating screen machine, in particular with an eccentric drive (4).

Images