FR3040376A1 - FILLING STATION WITH HIGH CADENCE BAGS, RESTRICTING DUST EMISSIONS - Google Patents

Abstract

Bag filling station with a powdery product (34), for bags (10) arriving substantially flat, this station (6) comprising lateral clamps (30) which hold the bag in position, and a nozzle (32). ) which enters the upper opening of the bag to deposit the product, this filling station further comprising a horizontal plate (20) forming a fork comprising a vertical slot (24) in which is inserted the front flat bag (10) its filling, and a means of descent of this tray depending on the filling of the bag.

Description

FILLING STATION WITH HIGH CADENCE BAGS, RESTRICTING EMISSIONS FROM

DUST

The present invention relates to a bag filling station with a powdery product for a bagging installation, as well as a method of operation of such a filling station, and a bagging installation comprising this filling station.

A type of known bagging plant with pulverulent products, presented in particular by the document FR-A1-2934846, comprises a continuous line of advancement of flat bags arriving vertically upstream. The bags have two side walls clad on each other, whose side edges are interconnected either directly to form a bag of small width, or by bellows unfolding to form a bag of large width.

The lower bottom of the bags is closed generally by folding and gluing. The upper part of the bags, also called bag head, remains open to allow filling. The bagging installation comprises a first filling station of the bag through the upper opening, then a position of compliance of the head of the bag around this opening, and finally a closure station of the bag, in particular by welding.

One can then have a finishing station putting up for example handles on the bags.

For filling the bag, a known type of item leaves the bag at the same height on the horizontal line, then clamps both sides of the head of the bag by two side clamps. Then we have the descent of a nozzle between these clamps in the upper opening of the bag, which injects the powdery product inside.

In addition, during the filling of the bag, it is possible to have a movable lower tray which makes small vertical strokes with a certain frequency for beating under the bottom of the bag, in order to help the deployment of this bag and the descent and by tamping the powdery product in this bag.

This filling station allows a high rate, the bag moving to the filling station on the same horizontal line which avoids additional time of rise and fall of this bag.

However the filling operation with the powdery product falling from a certain height to the bottom of the bag causes a significant dust emission inside, which escapes outwards on the sides of the nozzle between the two lateral clamps. squeezing the head of this bag.

Alternatively another type of known filling station comprises once the bag arrived on this station, a vertical movement of the bag, which introduces into the upper opening a fixed nozzle which is above.

By providing a fairly long nozzle, the lower outlet of the nozzle comes substantially to the bottom of the bag at the beginning of the filling. The bag is progressively lowered after this filling, which limits the height of drop of the product and the release of dust during filling. Finally, there is a lateral transfer of the bag which continues on the horizontal line.

However these movements up and down the bag with the necessary security controls, add a relatively large time that gives the machine a low rate.

In addition there is also a risk of bad unfolding of the bottom of the bag which causes defects, as well as an absence of compaction of the product which can then occupy a larger volume. We can alternatively add a settlement operation by a tray that taps on the bottom of the bag, but in this case slows the pace even more.

The present invention is intended to avoid these disadvantages of the prior art.

To this end, it proposes a bag filling station with a powdery product, for bags arriving substantially flat, this station comprising lateral clamps which hold the bag in position, as well as a nozzle which enters the upper opening of the bag. bag for depositing the product, this item being remarkable in that it comprises a horizontal plate forming a fork comprising a vertical slot in which the bag is inserted flat before filling, and a means of descent of this tray depending on the filling of the bag.

An advantage of this bag filling station and leaving the bag at the same height on a horizontal line of a bagging plant, it can begin filling by placing the fork up near the opening, then lower this fork according to the product inlet to obtain a gradual swelling of the bag from the top.

A control of the descent of the product and the speed of filling is obtained, which prevents a fall of this product on a high height and limits the emission of dust. There is also a high rate of the filling station avoiding further vertical movements of the bag, thanks to the horizontal movement remaining on the same line.

The filling station according to the invention may further comprise one or more of the following features, which may be combined with each other.

Advantageously, the slot comprises a lateral inlet of the bags in this slot having chamfers of entry. This facilitates the entry of bags into the slot, which allows to provide a relatively narrow slot ensuring good retention of the product.

In particular the tray can be supported at its end opposite the lateral entrance of the slot, by an arm releasing the space above this plate.

In this case, advantageously the arm passes through a partition behind which is a motorization of the descent means of the plate. The partition protects the engine from dust emissions from the filling station.

Advantageously, the filling station comprises two lateral clamps tightly clasping the nozzle in its filling position of the bag. This limits the openings allowing dust to escape from the bag during filling. The invention also relates to a method of operating a filling station having any one of the preceding features, which regulates the speed of descent of the tray by maintaining an upper surface of the product mass deposited in the bag, a distance of the nozzle substantially constant.

According to one embodiment, the operating method sets a predefined constant speed of descent of the plate. This process is simple to implement.

Alternatively the operating method can set a variable speed of descent of the tray, according to information on the current filling of the bag. This method is more complex to implement, but gives a better precision on the control of the descent height of the product.

Advantageously, the operating method controls at the end of filling a vertical oscillatory movement of the plate which hits under the bottom of the bag.

Advantageously, the operating method controls at the end of filling a clearance of the tray below the bottom of the bag, then performs a lateral displacement of the bag. The invention furthermore relates to a bagging installation successively comprising a bag filling station and a closure station for these bags, this bag filling station having any of the preceding characteristics. Other features and advantages will become apparent from the following description of the invention, a description given by way of example only, with reference to the appended drawings, in which: FIG. 1 is a diagram of a bagging installation seen front end comprising a bag filling station according to the invention, a bag being at the beginning of filling; - Figure 2 shows this installation according to the horizontal sectional plane ll-ll; - Figure 3 shows this installation with a bag in filling medium; - Figure 4 shows this installation with a bag at the end of filling; and - Figure 5 shows this installation after a transfer of the full bag and the arrival of a new empty bag.

Figures 1 and 2 show a bagging installation comprising a first station 2 for removing a bag which is flat 10, installed vertically, the opening of this bag being turned upwards.

The bag from a magazine 4, has two faces, one on the other, which can be connected directly together to form a narrower bag, or via lateral bellows to form a wider bag, and a bottom 12 which extends substantially horizontally when the bag inflates to take a tubular shape.

The bag 2 can be formed with any type of material, such as paper or plastic film. The bagging installation comprises means for transferring the bags 10 progressing to the right along a horizontal line, not shown, which bring successively along the arrow 14 the bags to a filling station 6, then following the arrow 16 to a station closing 8.

The filling station 6 comprises a horizontal plate 20 forming a fork, comprising a vertical slot 24 disposed in the axis of the installation, the opening of which is turned towards the first station for removing the bags 2. Each arm of the fork has at its front end an input chamfer 22 facilitating the entry of the bags 10 in the slot 24 of the fork, to be substantially adjusted in this slot with a reduced clearance.

The plate 20 is fixed at its right end to a horizontal arm 38, which goes backwards to pass through a vertical slot of a rear wall 36, disengaging the space above this plate. The front end of the arm 38 is guided by a vertical rail 40. The rear end of the arm 38 is fixed on a vertically sliding system 28 moved by a motor 26, which gives the plate 20 a vertical descent speed controlled according to the bag filling 10.

The motor 26 is disposed behind the vertical wall 36 disposed behind the installation, so as to protect it from the dust released possibly or accidentally.

The vertically sliding system 28 may comprise in particular a belt or a chain driven vertically by the motorization 26, a jack, or any other system such as a vertically disposed screw, causing by its rotation the descent of a nut.

The bag 10 is held at the filling station 6 by two lateral grippers 30 which clamp on each side the upper part of this bag flat, leaving between them a free central passage for inserting the lower end of a nozzle 32 who goes down in this opening.

The operation of the filling station 6 is as follows. Before the beginning of the filling of the new empty and flat bag, inserted in the slot 24 of the plate 20, this plate is in the high position, a little below the upper opening of the bag.

Subsequently, a progressive filling of the bag by a removal of the product 34 injected by the nozzle 32. The plate 20 maintaining the substantially flat bag 10 at its level, this clamping virtually prevents any product passage 34 below. Only the portion of the bag above the tray 20 inflates by removing the product 34, the lower portion of the bag 10 remaining flat.

During this beginning of filling the bag 10, the product 34 from the nozzle 32 falls into this bag at a low height, the plate 20 being close to this nozzle. It is then thanks to the controlled rate of descent taken by the product 34, little dust emission from the leaks on the sides of the nozzle 32.

FIG. 3 then shows a progressive descent 50 of the tray 20 as a function of the filling of the bag 10, which is linked to the product inlet 34 in this bag, allowing the base of the product mass retained by this tray to drop, leaving an upper surface of this mass always close to the nozzle 32.

Thus until complete filling of the bag 10, a low height of the product 34 in the bag which avoids the emission of dust.

Various means for controlling the speed of descent of the tray 20 depending on the filling of the bag 10, such as in particular a constant speed launched from the beginning of filling, or a speed controlled according to measurements given by sensors quantifying this can be used. filling level.

The level of filling of the bag 10 and the end of this filling can be controlled in particular by a gross weighing of the bag, by a net weighing of the amount of product 34 deposited therein, or by any other means such as for example optical sensors measuring the volume of this bag. The speed of descent of the plate 20 can be enslaved to these various means.

Figure 4 shows the bag 2 completely filled with the material 34, the tray 20 having arrived below this bag whose deployed bottom 12 forms a wide surface disposed above this plate.

The motor 26 of the plate 20 is then controlled to perform a vertical oscillatory movement 60 to come and tap with this tray the bottom of the bag 12, which cup the product 34 down well into this bag.

FIG. 5 shows the following step, the bag 10 filled at the filling station 6 being evacuated along the arrow 16 towards the closing station of the bags 8, after having passed over the arm 38 supporting the plate 20 which is placed in its low position under the bottom of the bag 12. In addition the installation can perform finishing operations of the filled bag, such as the installation of handles.

The tray 20 has begun to rise along the arrow 70, and a new bag 10 has been introduced into the slot of this tray along the arrow 14, from the bag removal station 2. The new bag 10 will be seized by the side clamps 30.

The filling of the new bag 10 begins after the arrival in the high position of the tray 20, and the descent of the nozzle 32 in the opening of this bag.

A bagging installation is obtained with a speed of operation and a high rate with bags that progress only in a horizontal movement between each station, avoiding vertical movements of these bags. In addition, it controls in a simple and effective manner the descent of the product which avoids a too abrupt fall generating dust and can lead to breakage of bags, while ensuring an efficient tamping of the material to optimize the size of the finished bag .

Claims (11)

1. Bag filling station with a powdery product (34), for bags (10) arriving substantially flat, this station (6) comprising lateral clamps (30) which hold the bag in position, and a nozzle (32) which enters the upper opening of the bag for depositing the product, characterized in that it comprises a horizontal plate (20) forming a fork comprising a vertical slot (24) in which the flat bag (10) is inserted. ) before filling, and a descent means (26) of the tray according to the filling of the bag. 2. Filling station according to claim 1, characterized in that the slot (24) has a lateral inlet of the bags in this slot having inlet chamfers (22). Filling station according to claim 1 or 2, characterized in that the plate (20) is supported at its end opposite to the lateral entrance of the slot, by an arm (38) releasing the space above this plateau. 4. filling station according to claim 3, characterized in that the arm (38) through a partition (36) behind which is a motorization (26) of the descent means of the plate (20). 5. filling station according to any one of the preceding claims, characterized in that it comprises two lateral clamps (30) fittingly clamping the nozzle (32) in its filling position of the bag (10). 6. Operating method of a filling station according to any one of the preceding claims, characterized in that it regulates the descent rate of the tray (20) by maintaining an upper surface of the mass of product (34) deposited in the bag (10) at a substantially constant distance from the nozzle (32). 7. Operating method according to claim 6, characterized in that it sets a predetermined constant speed of descent of the plate (20). 8. Operating method according to claim 6, characterized in that it sets a variable speed of descent of the tray (20) according to information on the current filling of the bag (10). 9. Operating method according to any one of claims 6 to 8, characterized in that it controls at the end of filling a vertical oscillatory movement (60) of the plate (20) which hits under the bottom of the bag (12) . 10. Operating method according to any one of claims 6 to 9, characterized in that it controls at the end of filling a clearance of the tray (20) below the bottom of the bag (12), then performs a lateral displacement of this bag. 11. Bagging plant successively comprising a bag filling station (6) and a closing station for these bags (8), characterized in that the bag filling station (6) is according to any one of the claims 1 to 5.