DE10153042C1 - Weighing device for loose material dosing has container holding loose material supported by carrier frame mounted on weighing cells - Google Patents

Abstract

The weighing device has the container (11) holding the loose material supported by a carrier frame (5) mounted on weighing cells (4), with a feed device, for transfer of loose material from the container to a filling space (2), coupled to the outlet of the container via a coupling pipe (16) supported by the carrier frame. The feed device is supported by a wheeled frame (21) with vertically retractable wheels (22). An Independent claim for an application method for a weighing device for loose material dosing is also included.

Description

The invention relates to a weighing device for a Weigh a pourable product from a container in a filling space according to the preamble of claim 1 and a method for using the weighing device.

Such devices are in many forms in the Industry, e.g. B. in the chemical industry and the Phar maindustrie, in use. They serve u. a. for loading of processing plants with the required products. All pourable products are listed here as pourable products Products in dry form as well as mechanically conveyed capable pasty products understood.

The invention particularly relates to such devices with which the actual introduced filling quantity is very can be measured precisely.

Such devices exist in the prior art gen generally from a base frame in which a stop tion to hold the containers with the pourable Product and a weighing device for determining the mass of the container are stored. With the weighing device can the gross mass of the container including that in it located product can be determined. Subordinate a conveyor for transferring the pourable Product present in the filling room.  

The amount of pourable poured into the filling chamber Product can be determined from the difference of the gross gross se at the beginning of the filling and to a certain later Time can be determined.

The problem here is that the accuracy of the Filling space weighed quantity of pourable product only can be determined inaccurately because it cannot be determined exactly is how much is left between the container and the Filling space, e.g. B. in the screw of a screw conveyor located. The determined difference in the gross mass of the Containers is therefore not identical to the one actually in mass introduced into the filling chamber.

US 5,466,894 A specifies a method for sagging given bulk fill weights from a weighing container in Transport containers, especially sacks, and an associated one Bulk bagging device with a scale. The before given bulk filling quantity is controlled by means of a control direction from the weighing container into the transport container discharged. The scale is a controlled differential scale designed which the from the weighing container into the Trans Bulk bulk quantity discharged via a differential weight loss of the weighing container gravime tric recorded and the bulk quantity discharge controls the specified bulk filling weight.

Solutions are also known in which a weighing machine is used Direction under the filling space is provided and the filling quantity can be determined directly. Such facilities are often bothersome and practical on processing plants not applicable in every case.

The invention has for its object a Einweageein direction for weighing a pourable product to specify a container in a filling room with which one predetermined filling quantity of a pourable product, with introduced into the filling chamber with high dosing accuracy can be easily demonized for the purpose of cleaning is animal. Furthermore, the task is a Specify procedures for using the facility.

The invention solves the problem for the weighing device indicated by in the characterizing part of claim 1  characteristics. The task for the procedure is through the features in the characterizing part of claim 7 solved. Advantageous developments of the invention are in the respective subclaims and are marked below along with the description of the preferred ones Implementation of the invention, including the drawing, shown in more detail.

The essence of the invention is that the conveyor direction with all associated elements as well as the container ner at least during the filling of the filling space are held within the weighing device in this way, that their entire mass acts on the weighing device. It can all as a conveyor according to the status of Technology suitable systems are used, e.g. B. Screw conveyors, vibratory conveyors and. a.

As part of the weighing device, load cells are on one Base frame arranged on which everyone else Support furnishing elements. The practical version the base frame is immaterial. For transmission The load on the load cells is supported by a support frame the one in which a connecting pipe is held. The top The end of the connecting pipe is in use with the Container connected and the lower end is with the För connected to the facility.

The holder of the elements that are cyclically cleaning are to be subjected to dismantling, d. H. that especially the conveyor quickly and easily removed from the weighing device  can. The means of making such a connector are available to the specialist in a variety of forms supply. Specific configurations of the connections according to claims 5 and 6 are in the following execution example described in more detail.

Another essential feature of the invention is in that the outlet opening of the conveyor or a separate filler neck that the conveyor protrudes into the filling chamber without force, or as far as that is sufficient, up to the filling opening of the filling space is sufficient. This ensures that no frictional forces or the like on the weighing device Act.

According to the invention, wheels are on the conveyor orderly. At least while weighing in a product The wheels in the filling area are opposite the bottom reason raised so that the entire mass of the Förderein direction acts on the load cells. To clean the most relatively heavy conveyor, the wheels can easily be lowered so that the conveyor from the Base frame can be pulled out. As a means of Raising and lowering the conveyor or the wheels are suitable pneumatic cylinders or other known in Actuators acting in the axial direction. Through one of the like facility is also the coupling of the Förderein direction to the connecting pipe much easier.

According to claim 2, it is advantageous between the Tragrah and the container to provide a vibration frame.  

Even a poorly pourable product can easily do this are brought out of the container.

Furthermore, it is advantageous according to claim 3 Outlet opening of the conveyor a shutter to be provided with the, after the introduction of the intended Filling quantity in the filling area, the filling process quickly can be canceled.

Between the connecting pipe and the container and / or can between the conveyor and the filling chamber according to claim 4 advantageously a compensator be arranged, the respective inner spaces Free and dust-free if necessary det.

The procedural use of the weighing device takes place in such a way that after installation of the sample direction, with the wheels raised and one on the tra grahmen or if necessary on the vibration frame placed container, first one on the load cells acting gross mass output value is determined.

Then the conveyor is put into operation and their closure flap and an existing container ver tailgate opened. In situ, i.e. H. during filling of the filling chamber, the gross mass is determined and the difference between the currently determined gross mass and gross mass off current value determined. When the intended filling is reached the closing flap is closed.  

According to claim 8 can advantageously before reaching the delivery capacity of the delivery device are lowered, before lowering the För if necessary, an existing container shipping closing flap can be closed. With this procedure Management will cause the last required Proportions of the intended filling quantity of a pourable Product introduced into the filling chamber in very fine doses be, which increases the dosing accuracy significantly becomes. It is also advantageous that the funding direction is emptied to a minimum.

The invention is illustrated below in one embodiment game explained in more detail.

The drawing shows in Fig. 1 is a Einwaageeinrichtung invention for pourable products in a side view and in Fig. 2 shows the detail Z in FIG. 1.

The device is for use in the pharmaceutical industry provided and is intended for a recording volume of a Con tainers for a bulk of approx. 1 cubic meter a do enable accuracy of 100 grams of product weight. Furthermore, the entire facility for cleaning in an external cleaning system can be easily dismantled.

As can be seen from FIG. 1, the exemplary weighing device is arranged above a building ceiling 1 . As a filling room 2 there is a processing system below the building ceiling 1 .

The weighing device consists of a base frame 3 which is fixedly mounted on the building ceiling 1 . At the four corners in the upper part of the base frame 3 there are one load cell 4 each, which are interconnected within a control of the weighing device via a synchronous unit and act as a uniform weighing device. Above the load cells 4 there is a frame 5 which is supported exclusively on the load cells 4 .

At the upper corners of the support frame 5 there are four vibration dampers 6 in the form of silent blocks, on which a vibration frame 7 is supported in the exemplary embodiment according to claim 2. To generate a vibration, the vibrating frame 7 is connected to an eccentric motor 8 .

In the exemplary embodiment, the vibration frame 7 is adapted to the outer configuration of the support frame 5 and has a centering corner 9 at each of its upper four corners, into which a foot 10 of a container 11 can engage, in such a way that the container 11 is secure on the vibration frame 7 can be put on. As a container 11 such any type can be used, provided that it is equipped with corresponding feet 10 and has a suitable centric outlet.

To dock the container 11 to the weighing device, a docking connector 14 is held on the vibrat ion frame 7 in the exemplary embodiment. Without the vibrating frame 7, the docking neck would have to be held directly on the supporting frame 5 .

The outlet of the container 11 is formed in the exemplary embodiment as a connecting flange 12 with a container flap 13 . In this case, the connection flange has 12 after placement of the container 11 on the frame vibration 7, that when the legs 10 are positioned in the 9 Zentrierecken their final position, compared with a Andockflansch 28 mm at a distance of about 4 at the docking port fourteenth In this position, the connection flange 12 and the docking flange 28 are clamped together.

For this purpose, as shown in FIG. 2, three clamps 29 are each connected to a pneumatically driven rotating device 30 . If the rotating devices 30 are actuated, the clamps 29 overlap the connecting flange 12 and the docking flange 28 such that the container 11 is axially locked against the vibrating frame 7 .

To seal the interior spaces on the connecting flange 12 and on the docking flange 28 from the surroundings, an annular seal 31 is provided in the dock flange 28 . The ring seal 31 has an inner cavity which is connected to a compressed air line 32 , and acts axially against the connecting flange 12 . After the connection flange 12 has been clamped to the docking flange 28 , an internal excess pressure can be built up in the ring seal 31 via the compressed air line 32 . The ring seal 31 expands in the axial direction from a rest position ( 31 '), as shown on the left side of FIG. 2, in a sealing position ( 31 "), as shown on the right side of FIG. 2 can be seen.

A connecting tube 16 is mounted centrally on the supporting frame 5 via two easily detachable connecting angles 17 . The upper end of the connecting tube 16 is connected to the docking connector 14 via a first compensator 15 . As a first compensator 15 there is a slack hanging dust-permeable fabric sleeve.

At the lower end of the connecting tube 16 , a screw conveyor 19 is flanged easily detachable. For this purpose, there is a flange 18 on the connecting tube 16 and a flange 33 on the screw conveyor 19 . The screw conveyor 19 is mounted in a chassis 21 with wheels 22 .

The flanging of the screw conveyor 19 to the connec tion tube 16 takes place via three fixed brackets 20 , two brackets 20 being provided on the flange 18 and one bracket on the flange 33 . The alignment of the brackets 20 is such that they do not hinder the retraction of the chassis 21 into the base frame 3 into a position in which the flanges 18 and 33 are aligned axially one above the other and in the end position the brackets 20 on the flange 18 Grip over flange 33 , while the clamp 20 on the flange 33 engages over the flange 18 . After reaching this position, the flange connection can be clamped dust-tight with a ring seal that can be subjected to an internal overpressure, similar to the ring seal 31 on the docking flange 28 .

The wheels 22 on the chassis 21 are each equipped with a pneumatic cylinder 23 , via which the wheels 22 can be raised or lowered relative to the chassis 21 . In Fig. 1 a position is shown, in which the wheels are raised and have no contact with the ground 22. The wheels 22 are adjusted in height in such a way that a gap of approximately 4 mm is present between the flanges 18 and 33 when supported on the building ceiling 1 and in the end position of the extended pneumatic cylinders 23 . As already explained in connection with the ring seal 31 on the dock flange 28 , this distance from the ring seal 31 can be sealed well.

On the screw conveyor 19 , an outlet opening 24 is provided on the left in FIG. 1, which is force-free with a filler neck 25 that is mounted firmly in the ceiling 1 of the building. The filler neck 25 is placed dust-tight on an opening of the filling space 2 .

The force-free connection between the outlet opening 24 and the filler neck 25 takes place via a second compensator 26 , which, similar to the first compensator 15 , is realized in the form of a slack hanging dust-impermeable fabric sleeve, so that the screw conveyor 19 is connected to the filling chamber 2 practically without force ,

A closure flap 27 is also provided directly above the outlet opening 24 . This is designed as a so-called quick-closing flap, which reacts very quickly. This ensures that after determining a specific filling quantity of the bulk material which has been filled into the filling space, no bulk material falsifying the intended filling quantity can flow into the filling space 2 .

The entire mass of the screw conveyor 19 with the product located in its interior and the chassis 21 depends on the flange 18th This load is transmitted from the flange 18 through the connecting pipe 16 and the connec tion angle 17 to the support frame 5 and acts in combination with the mass of the vibrating frame 7 , including the docking neck 14 and the gross mass of an existing container 11 on the weighing device in the form of the four load cells 4th

The weighing device according to the invention is described in more detail below in the application. Starting from a use of the device, the screw conveyor 19 should first be brought into a washing device for the purpose of cleaning.

For this purpose, according to the position shown in the drawing, the wheels 22 on the chassis 21 are lowered via the pneumatic cylinders 23 , so that the screw conveyor 19 is supported on the building ceiling 1 . In this position, the internal overpressure in the ring seal between the flanges 18 and 33 is reduced. As a result, the tension is released and the ring seal assumes an axially retracted position (corresponding to ring seal 31 'in FIG. 2, left side). The flanges 18 and 33 are thus free from one another again and have a spacing of approximately 4 mm. At the same time, the second compensator 26 is also released from the outlet opening 24 .

As a result, the chassis 21 is laterally displaced with respect to the axis of the flange 18 in such a way that the brackets 20 do not hinder an axial removal of the flanges 18 and 33 from one another. Thereafter, the pneumatic cylinder 23 is relieved, which, when the wheels 22 are still seated on the building ceiling 1 , the chassis 21 is lowered with the screw conveyor 19 and can be moved out of the base frame 3 .

For the purpose of cleaning, the first compensator 15 is released and the docking connector 14 can be from the vibrating frame 7 and the connecting tube 16 with the flange 18 can be separated from the connecting angles 17 .

After cleaning the individual elements, in particular the screw conveyor 19 , these can be reassembled in reverse order, so that, as already described above, the entire mass of the chassis 21 and the screw conveyor 19 and the other associated elements are fully on the Load cells 4 acts.

Subsequently, a new container 11 can be stretched into the center 9 and the connecting flange 12 of the container 11 connected to the docking flange 28 on the docking neck 14 . This also affects the gross mass of the container 11 on the vibrating frame 7 and the Tragrah men 5 on the load cells 4 .

When using the weighing device, the gross mass output value is first determined in accordance with the method according to the invention as the basis for weighing in a planned quantity of a pourable product. For example, 25 kg of a pourable product should be introduced from the container 11 into the filling space 2 . For this purpose, the container closure flap 13 is opened, the screw conveyor 19 is put into operation and the closure flap 27 is opened. The pourable product reaches the screw conveyor 19 by gravity. As long as the product is inside the screw conveyor 19 , the gross mass does not change. Only when a part of the pourable product leaves the outlet opening 24 does the mass of this part no longer act on the weighing device and the gross mass then measured is lower.

The difference between the gross mass initial value and the gross mass determined last corresponds to the filling mass of the pourable product introduced into the filling chamber. It is immaterial how much of the product is still in the screw conveyor 19 . In accordance with the method, the filling mass is determined in situ.

Using the method steps according to claims 8 and 9, the conveying capacity of the screw conveyor 19 is reduced at the end of the filling. Based on the fact that there are about 5 kg of pourable product in the screw conveyor 19 at a normal conveying capacity, the container closure flap 13 is closed at the intended filling quantity of 25 kg after determining a current filling quantity of approx. 21 kg. This means that there is still an amount of approx. 5 kg of the pourable product available for the remaining filling quantity that is already in the screw conveyor 19 . This quantity present within the screw conveyor 19 is sufficient for the total filling quantity provided, a tolerance filling quantity of approximately 1 kg being available.

In parallel to the closing of the container closure flap 13 or a short time later, the speed of the screw conveyor 19 is also reduced according to the method, so that its conveying capacity drops significantly at least at the end of the filling. The lowering of the conveyor line can be carried out in stages or in stages.

Under these process conditions and with further in situ measurements, the filling process is continued until the intended filling mass is reached. At this time, the shutter 27 is closed and the screw conveyor 19 is stopped.

The weighing device according to the invention enables the introduction of an intended filling quantity into the filling space 2 with good reproducibility and high accuracy. Even with relatively coarse bulk goods, filling materials can be weighed into the filling chamber with an accuracy of 100 grams difference.

The invention is of course not limited to the described embodiment. It is thus readily possible to adapt the device according to the invention to the respective technical circumstances. Other conveyor systems, e.g. B. vibratory conveyors or paddle conveyors can be used. Other weighing systems available to those skilled in the art can also be provided, and individual elements can be replaced in a professional manner by elements with the same effect. For example, the wheels 22 can also be replaced by a roller conveyor and runners on the chassis. The ring seal can also be operated with an internal vacuum in a technically equivalent manner instead of with an internal overpressure.

List of the reference symbols used

1

building ceiling

3

base frame

5

supporting frame

7

Bed frame

9

Zentrierecke

11

Container

13

Container closure flap

15

first compensator

17

connecting brackets

19

screw conveyor

21

chassis

23

pneumatic cylinder

25

filler pipe

27

flap

29

clip

31

ring seal

33

flange

2

filling space

4

load cell

6

vibration

8th

eccentric motor

10

foot

12

flange

14

docking port

16

connecting pipe

18

flange

20

clip

22

bikes

24

outlet

26

second compensator

28

Andockflansch

30

rotator

32

Compressed air line

Claims (9)

1. Weighing device for weighing a pourable product from a container ( 11 ) into a filling space below it ( 2 ), consisting of a weighing device for determining the mass of the container ( 11 ), a carrying device for the container ( 11 ) in the form of a on load cells ( 4 ) mounted support frame ( 5 ) and a conveyor for transferring the pourable product with an outlet opening ( 24 ), which can be connected to the loading chamber ( 2 ) without force, a connecting tube ( 16 ) being held in the support frame ( 5 ) whose upper end can be connected to an outlet opening on the container ( 11 ) and at the lower end of which the conveyor device is detachably fastened, the conveyor device being held in a chassis ( 21 ) and the chassis ( 21 ) having wheels ( 22 ), which can be moved vertically relative to the chassis ( 21 ). 2. Weighing device according to claim 1, characterized in that between the support frame ( 5 ) and the container ( 11 ), a vibration frame ( 7 ) is present, which supports vibration damper ( 6 ) on the support frame ( 5 ). 3. Weighing device according to claim 1 or 2, characterized in that a closure flap ( 27 ) is present at the outlet opening ( 24 ). 4. Weighing device according to one of claims 1 to 3, characterized in that a compensator ( 15 , 26 ) is arranged between the connecting tube ( 16 ) and the container ( 11 ) and / or between the conveying device and the filling chamber ( 2 ), that connects the respective inner spaces with each other without force. 5. Weighing device according to one of claims 1 to 4, characterized in that peripherally to a flange ( 18 ) on the connecting tube ( 16 ) and to a flange ( 33 ) on the screw conveyor ( 19 ) brackets ( 20 ) are present, which are in the axial position overlap the other of the flanges ( 18 ) and ( 33 ) at a predetermined distance from one another and that an annular seal which can be acted upon by an internal overpressure is arranged between the flange ( 18 ) and the flange ( 33 ) and which seals the flanges ( 18 ) and ( 33 ) axially clamped at internal overpressure. 6. Weighing device according to one of claims 1 to 4, characterized in that axially to a connection flange ( 12 ) on the container ( 11 ) on the docking neck ( 14 ) has a docking flange ( 28 ) and peripherally thereto rotating devices ( 30 ) with brackets ( 29 ) are present, such that the brackets (29) the connection flange (12) and the Andockflansch (28) can engage, and that provided a pressurizable with an internal pressure ring seal (31) between the connecting flange (12) and the Andockflansch (28) that axially clamps the connection flange ( 12 ) and the docking flange ( 28 ) in the event of internal overpressure. 7. A method for using a weighing device according to one of claims 3 to 6, wherein after assembly of the weighing device, with raised wheels ( 22 ) and a container ( 11 ) placed on the supporting frame ( 5 ) or optionally on the vibrating frame ( 7 ). a gross mass output value acting on the load cells ( 4 ) is determined, the conveyor is put into operation and the closure flap ( 27 ) and an existing container closure flap ( 13 ) are opened, the gross mass is determined in situ as the fill quantity in the filling space has been filled, the difference between the currently determined gross mass and the gross mass output value is determined and the closure flap ( 27 ) is closed when the intended filling quantity is reached. 8. The method according to claim 7, characterized in that before When the intended filling quantity is reached, the delivery rate of the Conveyor is lowered. 9. The method according to claim 8, characterized in that the container closure flap ( 13 ) is closed before, with or after the lowering of the conveying capacity.