DE8910411U1 - Analytical sieve device - Google Patents

Description

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30 August 1389

PATENT ATTORNEYS .... . Reference number:

CONRAD KÖCHLING ' 1 ']' DIPL.-.NG. CONRAb-JOACHIM KÖCHLING _o Ve^aÄtr. 24

FleyerStreet 135,5800Hagen D-5630 Remscheid

Call (02331) 81164+ 850 33 Telegram«: PatentkdchRng Hagan

Accounts: Comrnerzbank AG. Hagen Onar^wprke GmbH

(BLZ46040042»3515095 yuarzverxe umon.

spartua·Hagan 100012043 Kaskadenweg 40

Poatachacfc: Dortmund 5989-460 D-5020 Frechen

VNR: 14&mdash;5Ä-54

Serial No. .

CJK/Li.

Anal y sens £ ^. &ogr; device

The invention relates to an analytical sieve device, consisting of a frame-mounted sieve set with one or more sieve inserts stacked on top of each other,

a sieve pan arranged at the bottom and a device for exciting the sieve fabric of the sieve inserts.

Such an analytical sieve device is known, for example, from the Rhewum brochure "Analytical Sieve Devices" List 2000, 12.86.

Sieve analyses are a very important part of the overall field of particle size measurement technology. They are used to determine the particle size distribution of free-flowing products such as dust, flour, powder or granules and are carried out in the wet or dry phase depending on the product.

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carried out. Depending on the grain size range, test sieves of known mesh size (according to DIN 4.188) are stacked to form a sieve tower with a mesh size decreasing from top to bottom and sieved using a suitable test sieving machine or by hand. After the sieving time determined using DIN 66165 has ended, the residues remaining on the test sieves are removed from the sieves using a brush, broom or similar and filled into appropriate containers and weighed. The masses of the individual sieve residues and the passage through the finest sieve are added up and the individual weights are put in relation to the total weight. The grain size distribution determined in this way is either shown as a table or shown in appropriate grain size grids as a curve or histogram. In particular, the removal of the residues after sieving, the gentle handling of the sometimes very fine sieve fabrics and the precise weighing of the egg masses require conscientious work and a corresponding amount of time from the laboratory technician. The

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Calculating the correlation distribution to be specified in mass or weight percent or the graphical representation in a grain size grid require appropriate knowledge and sufficient experience. Especially in quality control, subjective* influence on the sieving result by the operator must be excluded. Depending on the material, fineness, sieving time and required evaluation or representation of the sieve analysis, a time expenditure of 15 to 45 minutes per analysis is required.

Based on this state of the art, the invention is based on the object of creating an analytical sieve device in which human influences are largely excluded and in addition the analytical data can be recorded much faster and more accurately.

To solve this problem, the invention proposes the sieve inserts from each other and from the sieve pan

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can be lifted off by means of actuators fixed to the frame,

that the entire sieve set including actuators can be pivoted about a horizontal axis into a tilting position

and that a screenings collecting device is arranged in the discharge area of each sieve insert and the sieve pan.

This design makes it possible to automate the sieving process as much as possible for the purpose of analysis. The material to be sieved can be filled into the top sieve insert of the sieve tower manually or using suitable conveyor devices. The sieve tower is then set into vibration by suitable exciters, whereby the strength of the vibration, for example the oscillation range of the excitation magnet, can be individually adapted to the respective requirements.

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Impulse is possible in order to be able to process even difficult to sieve materials well. The sieving time is freely selectable, whereby after the sieving process has ended, the sieve inserts are lifted from each other and from the sieve pan using the actuators fixed to the frame. This creates a gap between the individual sieve inserts or the sieve insert and the sieve pan. The entire sieve set can then be manually or preferably motor-driven pivoted around a horizontal position into a tilting position, whereby a sieve material collecting device is arranged in the discharge area of each sieve insert and the sieve pan, into which the sieve material contained in the individual elements is tipped separately when the sieve set is pivoted. To completely empty the sieve inserts and the sieve pan, it is possible to briefly switch on the vibration exciter of the sieve set in order to also empty the individual elements.

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to throw the remaining components into the assigned >material collection device. After all sieve inserts and the sieve pan have been completely emptied, the entire sieve set is swiveled back into the starting position and the sieve inserts are pressed against each other and against the sieve pan using appropriate actuators, so that a closed sieve tower is created again. This makes it possible to refill and sieve. Except for the filling of the samples, the sieving process runs independently and without manual intervention, so that the sieve analysis can be shortened overall and unaffected by operating errors. There is no need to remove the individual sieves after sieving has been completed and to manually empty the sieve inserts. The cycle time of the analysis sieve device and thus the possible number of sieve analyses per unit of time depends practically only on the necessary sieving time for the various products. The preferably fully

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Automatic loading and emptying of residues requires only a fraction of the time previously required.

An advantageous further development is seen in the fact that the sieve set is guided axially displaceably on rods that are held in place parallel to the central vertical axis of the sieve tower, that the sieve inserts are held against each other and against the sieve pan by means of energy accumulators, in particular tension springs, held on or near the sieve pan, that actuators, in particular fluid cylinders, that can be actuated against the direction of action of the energy accumulators, are arranged, by means of which the sieve inserts can be lifted off the sieve pan and from each other, whereby the sieve inserts are connected to each other and to the sieve pan via tension rods that can be changed to a limited length, the maximum change in length of which corresponds to the throwing distance of the sieve inserts from each other or from the sieve pan.

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The energy storage devices can preferably be designed as helical tension springs, while the actuators can be designed as pneumatic cylinders. The sieve tower, which is held in the closed position in the normal position by the energy storage devices, is divided into individual elements by actuating the actuators, in particular pneumatic cylinders, which are moved by means of the pneumatic cylinders on the rods that serve as guides against the force of the energy storage device. The length-adjustable tie rods limit the relative axial displacement path of the individual sieve inserts to one another, so that under the influence of the actuator, in particular the pneumatic cylinder, defined gaps are formed between the individual sieve inserts and the sieve pan. After pivoting and emptying the sieve inserts, the actuator is reset, in particular the pneumatic cylinders are vented, so that the sieve inserts are moved under the influence of the

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of the energy storage, in particular the screw suction devices, are again pushed together on their sides. The analytical sieve is then ready for further analysis and sieving.

The tension anchors, which can be adjusted in length to a limited extent, can be formed, for example, by chains or rope elements.

It is preferably provided that the length-adjustable tie rods are tabs provided with elongated holes, which are fastened with one end part to a sieve insert or to the sieve pan and whose other end part, which has the elongated hole, is penetrated in the area of the elongated hole by a driver bolt of the immediately adjacent sieve insert, whereby the driver bolts are arranged in one end area of the respective elongated hole when the sieve inserts are held against one another and in the other end area of the elongated hole when the sieve inserts are lifted away from one another.

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Furthermore, it is preferably provided that the screening material collecting device is formed by funnels arranged in a straight line one behind the other, at the opening of which the edges of the sieve inserts lifted apart from one another and the sieve pan can be placed when the sieve set is pivoted by approx. 110° against the vertical.

Furthermore, it is preferred that screenings receiving containers and weighing devices are coupled to the screenings collecting device.

The design according to the invention ensures that the grain classes are discharged via the funnel combination into corresponding receiving containers, which are positioned on commercially available scales. The weighing devices are coupled with an evaluation electronics, by means of which the recorded data is transmitted to a computer, which transmits the data to a printer or a plotter for graphic representation. This design eliminates the possibility of errors that can occur due to incorrect reading of the scales or

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Calculation of percentage values. The risk of "adjusting measured values" by the operating personnel to specified target values, especially during routine tests, is also prevented. If the device is arranged accordingly in a product bypass, a continuous, fully automatic production control with the possibility of signaling in the event of deviation from the standard can be implemented depending on the required cycle time.

Furthermore, it is preferably provided that above the mouth of the uppermost sieve insert in the sieve layer a screening material conveying device opens, which in particular is preceded by further conveying devices and drying devices for screening material.

For example, a vibrating conveyor can be provided as a screenings conveying device, which can also be equipped with a heater in order to be able to carry out any necessary sample drying.

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A preferred further development consists in that each sieve insert comprises an annular frame part in which a sieve can be exchanged at a distance from the mouth edge and in the direction of passage following an impact base with large passage openings is held, that knocking balls are arranged with play between the sieve and the impact base and are held evenly distributed by means of a segment basket inserted with play.

It is preferably provided that the segment basket comprises an annular central segment, adjoining circular segments formed by radial webs and an annular body running around the outside, with a knocking ball being arranged in each segment.

The freely movable impact balls arranged between the actual test sieves and the impact bases, which are preferably held in certain zones by a freely movable segment basket, prevent

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clogging of the mesh and thus failure of the screening. This largely eliminates the need for cleaning the screen mesh. By fixing the knocking balls in the freely movable segment basket, the test screen mesh above is cleaned over almost the entire surface. The greatly reduced frequency of manual cleaning of the test screen mesh contributes significantly to increasing the service life of the potentially very fine and expensive screen mesh.

An embodiment of the invention is shown in the drawing and described in more detail below.

Figure 1 shows an analytical sieve apparatus in side view; Figure 2 shows the same from the front;

Figure 3 also seen from above; Figures 4 and 5 a detail in different positions;

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Figures 6 and 7 show a further detail in plan view and in median section.

The analytical sieve device essentially consists of a sieve set 3 with sieve inserts 12 stacked on top of each other in the embodiment 4 and a sieve pan 26 arranged at the bottom, with a vibration exciter in the form of an oscillating magnet 16 being attached below the sieve pan 26 to a base plate 17 forming a frame. The sieve inserts can be lifted off from each other and from the sieve pan 26 by means of actuators (pneumatic cylinders 13 and tension springs }.4) held firmly to the frame. The entire sieve set 3, including actuators, can be pivoted about a horizontal axis from the vertical normal operating position, which is shown in solid lines in Figure 1, into a tilted position, which is shown in dotted lines in Figure 1. The horizontal axis is formed by a pivot bearing. In the discharge area of each sieve insert

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12 and the sieve pan 26, a screening material collecting device (funnel combination 4) is arranged. The sieve set 3 is guided axially displaceably on rods 19 that are held fixed to the frame parallel to the central vertical axis of the sieve tower, whereby the sieve inserts are held against each other and against the sieve pan 26 by means of energy accumulators held on the sieve pan or on the base plate, in particular tension springs 14. Actuators that can be operated against the direction of action of the tension springs, in particular pneumatic cylinders 13, are held on the base plate 17, whereby their upper, free end in the drawing can be extended against a corresponding projection 27 of the uppermost sieve insert 12. The free end is formed by the free end of the piston rod of the pneumatic cylinder 13. To form a gap between the sieve inserts, the pneumatic cylinders can

13, on whose free ends the projections 27 are placed and the uppermost sieve

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insert 12 moves upwards against the force of the tension springs 14 of the drawing fig. 2. The sieve inserts 12 are connected to one another and to the sieve pan 2t» via tie rods which can be adjusted in length to a limited extent and whose maximum change in length corresponds to the throwing distance of the sieve inserts from one another or from the sieve pan.

When the pneumatic cylinders 13 are actuated, the topmost sieve insert 12 is raised and the following sieve inserts are taken along via the tie rods arranged between them until the maximum tension length of the tie rods is reached. In this position, a defined discharge gap is formed between the individual sieve inserts and also between the bottom sieve insert and the sieve pan ?6. The length-adjustable tie rods are formed by tabs 20 provided with elongated holes 27, which are shown in detail in Figures 4 and 5. At one end, the tabs 20 are attached to a sieve insert 12 or to the sieve pan, while the other end, the elongated hole

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The end part of the elongated hole 27 is penetrated by the driver pin 28 of the immediately adjacent sieve insert 12. The drivers 28 are arranged in relation to the elongated hole 27 in such a way that they are arranged in one end region of the respective elongated hole when the sieve inserts 12 are held in contact _with one another (see Figure 5) and in the other end region of the elongated hole 27 when the sieve inserts 12 are lifted away from one another (see Figure 4). The height of the discharge gap is defined by the length of the elongated hole.

The screenings collection device is formed by funnels of a funnel combination 4 arranged in a straight line one behind the other, at the opening of which the edge of the separated screen inserts 12 and the screen pan 26 can be placed when the screen set 3 is pivoted downwards by approximately 110° from the vertical. This is particularly evident from Figure 1 (see dot-dash position of the screen set 3).

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In the drawing, the funnels of the screenings collecting device open into screenings receiving containers 25 on the underside, which are placed on weighing devices 5. Above the mouth of the uppermost sieve insert 12 in the sieve position, a screenings conveying device in the form of a conveyor trough 2 is arranged. In addition, further conveying devices in the form of conveyor troughs 1 are provided, which can throw the conveyed material onto the conveyor trough 2. The conveyor troughs 1 are each coupled to a drying device for the screenings in the form of a heater 10.

As can be seen in particular from Figures 6 and 7, each sieve insert 12 comprises an annular frame part 30 in which a sieve 31 is exchangeable at a distance from the mouth edge and in the direction of passage a baffle base 32 with large passage openings is held. Knock balls 33 are arranged with play between the sieve fabric surface 31 and the baffle base 32 and are

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a segment basket 34, which is also inserted with play. The segment basket 34 has an annular central segment and circular segments formed by radial webs and can be surrounded by an annular body on the outside. A knock ball 33 is arranged in each segment.

The fully automatic sieve analysis machine shown in the drawing is able to break down prepared samples of a wide variety of products into individual fractions and weigh them.

A work cycle begins with any necessary sample drying in the vibrating conveyor trough 1 using the heater 10. The samples filled into the five conveyor troughs 1 shown in the example are dried in a position of the troughs 1 that is slightly tilted backwards in the conveying direction by pneumatic cylinders 8, with the vibration of magnetic drives 11 ensuring constant circulation of the material and thus short drying times for the samples. After reaching the set drying time depending on the product,

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After the selected drying time, the magnetic drives 11 of the troughs 1 are switched off and the troughs are brought into a horizontal position using pneumatic cylinders 8. According to the desired setting, the magnetic drive 9 of a trough 1 is now switched on and the dried material is conveyed without residue into the central conveyor trough 2, whose magnetic drive 11 is switched on at the same time. The sample is fed onto the top sieve of the sieve set 3 using the conveyor trough 2. The sieve of the top sieve insert 12 is the coarsest of the sieve tower consisting of four test sieve bottoms (DIN 4188) with the respective ball knocking device (reference numbers 33 and 34). It is of course also possible to equip a sieve tower with just one test sieve. These four test sieves with impact bottoms 32 and sieve pan 26 for the sieve passage of the finest sieve break the fed material down into five fractions. After completion of the filling process through the central conveyor trough 2, the

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The vibrating magnet 16 of the sieve set 3 causes the sieve tower to vibrate, whereby the strength of the vibration, i.e. the oscillation range of the magnet, can be individually adapted to the respective requirements. The activation of a superimposed pulse also enables the processing of materials that are difficult to sieve. At the same time, the magnetic drive 11 of the central conveyor trough 2 switches off.

During the freely selectable sieving time, the test sieves are firmly connected to the cutting floors 32 and the sieve pan 26 by the tension force of the tension springs 14. The ball knocking devices arranged below the actual test sieves contain a certain number of freely movable knocking balls 33, depending on the mesh size arranged above them, which are fixed by a segment basket 34, which is also freely movable. In conjunction with the vibration generated by the oscillating magnet 16, these knocking balls 33 prevent the meshes of the sieves from becoming clogged and thus the sieving from failing.

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The free mobility of the knocking balls 33 and the segment basket 34 means that the knocking balls 33 can move horizontally and vertically in the individual segments of the segment basket 34. The segment basket 34 can also rotate, so that the vibration of the vibrating magnet 16 also causes a rotational movement of the vibrating basket. This enables the knocking balls 33 to exert a largely uniform load on the sieve surface. After the necessary test sieve time has elapsed, the magnet 16 switches off. The two pneumatic cylinders 13 unlock the sieve tower guided by the guide rods 19 against the tension force of the tension springs 14. The sieve tower is tilted by a certain angle, for _example by 110°, into the position for emptying by means of a swivel drive 21 mounted on the frame 22. During the tipping process, the sieve inserts and the sieve pan 26 are emptied over the edge of their discs. After reaching the tipping end position (shown in dash-dotted lines in Figure 1), the vibrating

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magnet 16 is switched on briefly for complete emptying.

The individual grain classes flow separately via the funnel combination 4 into the corresponding containers 25, which are positioned on standard scales 5. The data determined by the scales are recorded and evaluated by an evaluation electronics, which can be arranged in the control cabinet 6, for example, and fed to a computer, which controls corresponding devices for graphic display, for example a printer or plotter. After all sieve inserts 12 and the sieve pan have been completely emptied, the pneumatic cylinders 13 are vented so that the tension springs 14 pre-tensioned by the pneumatic cylinders 13 pull the individual elements of the sieve tower together again and press them against one another. The swivel drive 21 returns the complete sieve set 3 to the starting position for refilling or sieving.

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This arrangement considerably shortens the time required to carry out the sieve analysis, since apart from filling the samples into the feed channel 2, the sieve analysis is or can be carried out completely automatically. The removal of the individual sieve inserts 12 after sieving has been completed, the emptying of the sieve inserts 12 and the weighing of the quantities removed from the sieve inserts are no longer necessary. The cycle time of the analysis sieve device and thus the possible number of sieve analyses per unit of time is essentially only dependent on the sieving time of the various products. The fully automatic filling and emptying of the residues takes only a fraction of this time. The tendency of the sieve meshes to become clogged, which varies depending on the material being sieved, and the associated need for cleaning the mesh is largely eliminated by using the ball knocking device (33, 34). This ensures the cleaning of the above-mentioned

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The test sieve fabric is spread over almost the entire surface. The greatly reduced frequency of manual cleaning of the test sieve fabric contributes significantly to increasing the life of the sieve fabric, which can be very fine and expensive. The test sieves used are normal, commercially available test sieves with a diameter of 200 mm and a height of 50 mm. If replacement is necessary, the sieve fabrics can be very easily removed from their holders and replaced with a new sieve.

The analytical sieve apparatus enables a working method that is largely error-free, since incorrect reading of the scales 5 and conversion to corresponding percentage values is not necessary.

In addition, some parts of the device are explained.

In drawing figure 2, bearings 7 are shown, which allow the conveyor troughs 1 to pivot out of the horizontal

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tal normal working position into a position inclined against the conveying direction. 23 designates a frame on which the control cabinet 6 is arranged and which is a component of the overall device. 24 designates a storage area which is arranged above the control cabinet 6.

The invention is not limited to the embodiment, but is variable in many ways within the scope of the disclosure.

All new individual and combination features disclosed in the description and/or drawing are considered essential to the invention.

Claims (8)

Rhewum/Quartzwerke 9804/89 - 27 protection claims I. Analysis sieve device, consisting of a sieve set which can be held fixed to the frame and has one or more sieve inserts stacked on top of each other and a sieve pin arranged at the bottom and a device for exciting the sieve fabric of the sieve inserts, characterized in that the sieve inserts (12) can be lifted off from each other and from the sieve pan (26) by means of actuators which are held fixed to the frame, that the entire sieve set (3) including actuators can be pivoted about a horizontal axis into a tilting position , and that a screenings collecting device (4) is arranged in the discharge area of each screening insert (12) and the screening pan (26). 2. Analysis sieve device according to claim 1, characterized in that the sieve set (3) is guided axially displaceably on rods (19) fixed to the frame parallel to the central axis of the sieve tower, · · t ff «1 &bull;&igr; '··" "ss'i I Rhewum/Quartzwerke 9804/89 - 28 - that the sieve inserts (12) are held against each other and against the sieve pan (26) by means of force accumulators, in particular tension springs (14), held on or near the sieve pan (26), that actuators, in particular fluid cylinders (13), which can be actuated counter to the direction of action of the energy storage device are arranged, by means of which the sieve inserts (12) can be lifted off the sieve pan (26) and from one another, the sieve inserts (12) being connected to one another and to the sieve pan (26) via tie rods which can be changed in length to a limited extent and whose maximum change in length corresponds to the throwing distance of the sieve inserts (12) from one another or from the sieve pan (26). 3. Analysis sieve device according to claim 1 or 2, characterized in that the length-adjustable tie rods are tabs (20) provided with elongated holes (27) which Rhewum/Quartzwerke 9804/89 - 29 - !Sit. l.iTGm Smsn unutcli 5&Pgr; ciliSiu Slcueliiaö t £. (12) UiSW. are fastened to the sieve pan (26) and the other end part of which, having an elongated hole (27), is penetrated in the region of the elongated hole (27) by a driving pin (28) of the immediately adjacent sieve insert (12), the driving pins (28) being arranged in one end region of the respective elongated hole (27) when the sieve inserts (12) are held against one another and in the other end region of the elongated hole (27) when the sieve inserts (12) are lifted away from one another. 4. Analysis sieve device according to one of claims 1 to 3, characterized in that the sieving material collecting device (4) is formed by funnels arranged one behind the other in a straight line, at the opening of which the edges of the sieve inserts (12) raised apart from one another and the sieve pan (26) can be pushed against when the sieve set (3) is pivoted by approximately 110° from the vertical. &bull;&Mgr; · · Rhevum/Quarzverke 980&agr;/89 - 30 - 5. Analysis sieve device according to one of claims 1 to Zl Hoftnrrh oelronnvairhneh . H a &OHgr;with" A er i-liehaiifAiif &mdash; ■» &mdash;_&sgr;-.&mdash;.&mdash;&mdash; .. &mdash; _v .- _ &mdash; ____ _&sgr; __ &mdash; __ catching device (4), screenings receiving container (25) and weighing devices (5) are coupled. 6. Analysis sieve device according to one of claims 1 to 5, characterized in that a sieve material conveying device (2) opens above the mouth of the uppermost sieve insert (12) in the sieve position, which is preceded in particular by further conveying devices (1) and drying devices (10) for sieve material. 7.· Analysis sieve device according to one of claims 1 to 6, characterized in that each sieve insert (12) comprises an annular frame part (3) in which a sieve (31) is exchangeable at a distance from the mouth edge and in the direction of passage a baffle base (32) with large passage openings is held, that between the sieve (31) and the baffle base ihewum/Quarzverke 9804/89 floor (32) knock balls (33) are arranged with play and are held evenly distributed by means of a segment basket (34) inserted with play. 8. Analysis sieve device according to claim 7, characterized in that the segment basket (34) comprises an annular central segment, adjoining circular segments formed by radial webs and an annular body running around the outside, a knocking ball (33) being arranged in each segment.