FR2727333A1 - DEVICE FOR RECOVERING LIQUIDS ADHESIVE TO BULK PARTS - Google Patents

Abstract

A liquid recovery device (3) adhering to loose parts (42) comprises a container (2) containing the liquid (3) and a rotary plunger cylinder (7). This plunger cylinder can be moved by means of a lifting device (8) from a lower position in the container (2) to an upper position above the container (2). An exhaust blower cap (27) comprising two half-shells (25, 26) is associated with the upper position of the plunger cylinder (7). The half-shells (25, 26) are fixed on pivoting arms (28, 29) which can pivot towards each other when the plunger cylinder (7) enters between the half-shells (25, 26) .

Description

DEVICE FOR COLLECTING LIQUIDS ADHERING TO

BULK PARTS

  The present invention relates to a device for recovering liquids adhering to loose parts, comprising: a rotary plunger cylinder receiving the parts, which consists of front walls provided with cylindrical circumferential surfaces and a cylinder envelope having holes arranged between the front walls; a container for the liquid, in particular for a galvanic or chemical treatment bath in the wet phase or for a rinsing bath; a lifting device receiving the plunger cylinder for moving the plunger cylinder from a lower position in the container to an upper position above the container; rotary drive means for the plunger cylinder; a blowing evacuation cupola associated with the upper position of the plunger cylinder, and comprising two half-shells movable relative to each other in a substantially horizontal manner, the plunger cylinder being able to be inserted from below between the half-shells when the half-shells are in a position where they are spaced from one another, the half-shells can be applied against the plunger cylinder; and a blower connected to the blowing exhaust dome. Such devices are used for galvanizing processes or for chemical processes taking place in a humid environment. The parts in each plunger cylinder are treated uniformly in each respective bath due to the rotational movement of the plunger cylinder. In such installations for galvanizing surfaces or treatment by chemical process taking place in a humid environment, it may be necessary to have a large number of treatment and rinsing baths so that each plunger cylinder is brought in, during such a treatment process, in several containers containing different liquids. During each transfer operation from one container to the next, the parts - in particular the parts which draw the liquid, carry a large quantity of liquid from one bath to the next. The volumes of liquid removed are, as a rule, considerably greater than the quantity of liquid required for galvanizing or for chemical processes taking place in a humid environment. The liquids removed are further transported to the next bath, so that the composition of said bath is

  modified, which is not desirable.

  In order to solve this problem, a device of the above-defined type is known from document DE 31 33 629 C2, in which the two half-shells are displaced relative to each other horizontally. After the plunger cylinder has risen from the container, the two half-shells are pushed one over the other so as to close the exhaust blower cap. This operation requires a lot of time since the closing of the exhaust blower cap can only start when the plunger cylinder is in its upper final position. In addition, it is necessary to have

  complex drives for moving the half

  shells. To this must be added that the half-shells are chambers in the form of cylindrical annular sectors whose internal wall applied to the support rods of the plunger cylinder is perforated. The danger that air does not circulate through the rooms but next to them, that is to say the recovery of

  liquid is insufficient, is considerable.

  We know from document DE 38 30 237 C2 how to enter a cylinder from below into a blowing exhaust cap, so that the blowing exhaust cap covers the upper half of the cylinder. Compressed air must be passed through the charge of loose parts. Because of the angle of slope formed by the parts located in the plunger cylinder due to their rotation, and because of the only partial filling of the plunger cylinder, there is the danger of not having sufficient pressure and that the air s escapes through a

  area not covered with parts of the cylinder casing.

  In order to solve these problems, it is known to have a pivoting flap on the compressed air cap to be placed at the top, to cover the sector of the envelope of the cylinder not covered by parts. In addition, the exhaust blower cap must be closed at the front ends by separate side walls which must be applied to each plunger cylinder, in order to create a closed pressure space between the exhaust cap and

the plunger cylinder.

  From document DE 39 39 601 A1, a device for recovering liquids is known comprising an approximately semi-cylindrical pressure chamber. Boundary walls in the form of cylindrical sectors are pivotally mounted on the lower edges of the pressure chamber. When the plunger cylinder is mounted in the pressure cap, the pivoting boundary walls

  are tilted to the outside of the plunger cylinder.

  The object of the present invention is to provide a

  device of the above-defined type, so that the half

  shells close to form the exhaust blower cap in a short time and with a simplified design. According to the invention, this object is achieved by a

  device of the type indicated at the beginning, in which the half

  shells are mounted on pivoting arms which can pivot towards one another when the plunger cylinder is inserted between the half shells. As the half-shells rotate instead of sliding linearly, the path that the center of gravity of each half-shell must travel, when closing or opening, is less than that of a linear movement. In addition, the closing operation is already completed during the terminal phase of the elevation movement of the plunger cylinder. The two effects help to reduce the time necessary to carry out the automatic closing of the exhaust hood and therefore to be able to pass the air in the exhaust hood and through the parts. As a result, production rates are increased overall. The paths having been reduced, the forces necessary for the acceleration of the masses and therefore the

  energy consumption are also found to be reduced.

  Preferably, the lifting device of the plunger cylinder is mechanically coupled to the pivoting arms so that they can pivot towards each other during the final phase of the movement of the plunger cylinder upwards. One can in particular link the pivoting arms to actuating arms which are applied against abutment surfaces provided on the lifting device during the final phase of the movement of the plunger cylinder upwards, and provide a spring which biases the pivoting arms tending to spread the half shells apart. It is achieved that no separate drive is necessary for the opening or closing movements of the half-shells of the exhaust blower cap, but that the necessary energies and forces are supplied by the lifting device. The design of the device is simplified and is particularly suitable for retrofitting existing installations already having plunger cylinders

and lifting devices.

  The pivoting arms are advantageously arranged so as to be movable in the direction of elevation of the plunger cylinder. This guarantees the exhaust blower cap, once closed, and the plunger cylinder are exactly centered with respect to each other. These additional features ensure that compressed air passes very efficiently through loose parts without the risk of air bypassing the parts. Other features, benefits and details of

  the present invention emerges from the following description

  of an embodiment with reference to the appended drawings, in which: - Figure 1 is a schematic elevation view of a device for recovering liquids, the plunger cylinder being in a container and the exhaust blower cap being opened; - Figure 2 is a top view of a plunger cylinder; and - Figure 3 is a view similar to Figure 1 with the plunger in the raised position in the discharge cap. The drawings show a part of a surface treatment installation (galvanization or wet phase processes). This installation comprises several containers 2 arranged one after the other in a working direction 1, only one of the containers being shown. In the containers 2 is a liquid 3 forming a treatment or rinsing bath. Above the containers 2, rails 4 are arranged in the working direction 1. A carriage 5 mounted on casters 6 rests on these rails 4. A plunger cylinder 7 can be suspended from each carriage 5 by means of a lifting device 8. For this purpose, two guide bars 8a are mounted on the carriage, and extend parallel and vertically downwards. On each of these guide bars is arranged a gripping device 8c which can slide vertically by means of a respective slide 8b. The plunger cylinder 7 is pivotally mounted on support means 9, by means of pins 10. The gripping devices 8c of the lifting device 8 can grip these support means 9 in order to lift the plunger cylinder 7 by means of the lifting device 8 from a container 2 or in order to lower the plunger cylinder 7 into a container 2. Furthermore, the slides 8b are connected to each other by means of a lifting beam 8d. The lifting device 8 is driven by means of a device

  drive not shown in the drawing.

  The plunger cylinder 7 has front walls in the form of circular discs 11, 12, which each have a cylindrical circumferential surface 13, and on which the pins 10 are fixed. The plunger cylinder 7 comprises, between the front walls 11, 12, a cylinder casing 14 comprising support rods 15 connecting the front walls 11, 12, support rods whose outer surfaces 16 are flush with the circumferential surfaces 13 of the walls front 11, 12. Cylinder casing sectors 17 are fixed between neighboring support rods 15, small openings 18 being formed in these sectors to allow air or liquid to enter. One of the cylinder envelope sectors 17 is produced in the form of a cover 19 by means of which a

  filling or emptying opening 20 can be closed.

  A toothed ring 21 is fixed on the plunger cylinder 7 in the vicinity of a front wall 11. A drive pinion of a drive motor (not shown) meshes on this crown to rotate the plunger cylinder 7. On the upper edge of each container 2 are provided with guiding prisms 22 into which engage centering pins 23 carried by the support means 9 when the plunger cylinder 7 is lowered into a container 2. A device 24 is fixed to the carriage 5 for recovering the liquid 3 from each container 2. This device comprises a blowing cap for discharge 27

  formed from two half-shells 25, 26. The half-shells

  shells 25, 26 are installed on respective pivot arms 28, 29 mounted on the carriage 5 so as to be able to pivot about pivot axes 31, horizontal and parallel to the axis of rotation 30 of the plunger cylinder 7. The pivot arms 28, 29 are mounted on their respective pivot axes 31 by means of oblong guide holes 32, so that they can slide to modify their position in height. So-called springs 33 working in

  compression push swivel arms 28, 29 and half

  corresponding shells 25, or 26 towards the lower position. The pivoting arms 28, 29 in the form of double levers are connected together, in the region of their upper ends, by means of a pretended spring 34

  working in traction, which pulls - see figure 1 - the half

  shells 25, 26 in a position where they are spaced from one another and where the exhaust blower cap 27 is therefore open. Instead of such a tension spring 34, it is also possible to fix, at a suitable location, counterweights on the pivoting arms 28, 29 producing the same effect. On the pivoting arms 28, 29 are provided actuation arms 35 directed towards one another and each carrying an adjustable actuation stop 36 located on

  the path of the lifting beam 8d.

  The half-shells 25, 26 are formed in an essentially identical manner and arranged symmetrically with respect to each other. They each comprise an upper sector 37 having roughly the shape of a funnel and extending approximately over the zone corresponding to the interval between two neighboring support rods 15. In the usual embodiment of such plunger cylinders 7 provided with six support rods 15 arranged at equal angular distances, the sector 37, in the form of a funnel, of each half-shell 25, 26 thus extends over a circumferential angle of 60. A zone 38 in the form of a cylindrical sector is connected to each sector 37 in the form of a funnel. This zone 38 is applied sealingly against the circumferential surfaces 13 of the front walls 11, 12 and against the external surface 16 of the support strips 15 when the discharge cap is closed. The radius of these zones 38, in the form of a cylindrical section therefore corresponds to the radius of the front walls 11, 12 of the plunger cylinder 7. In order to make the sealing particularly effective, it is possible to place zones 38 in the form of zones of cylindrical sector and front parts 39 of sectors 37 in the form of a funnel, seals 40 applying against each circumferential surface 13 of each front wall 11. The zones 38 in the form of cylindrical sector extend over a circumferential area of about 90 so that, when the discharge cap 27 is closed, there remains a lower drip opening 41 extending

  at a circumferential angle of about 600.

  The operating mode of the device 24 will be

described in the following.

  The plunger cylinder 7 is filled approximately one third full with small loose parts 42. It is located in the container 2 in the treatment or rinsing bath formed by the liquid 3. The rotary drive of the plunger cylinder 7 takes place in the direction of rotation 43 which, in the embodiment shown, thus corresponds to the anticlockwise direction, so that the parts 42 form in the plunger cylinder 7 a slope 44 by

compared to the horizontal.

  After the end of the treatment, the plunger cylinder 7 is lifted by means of the lifting device 8 in the direction of the carriage 5 while the rotary drive continues by means of a drive system (not shown) arranged on the lifting device 8. The half -shells 25, 26 are sufficiently spaced from one another so that the plunger cylinder 7 can be introduced therebetween. Stop surfaces 45, formed on the lifting beam 8d, come into contact with the actuating stops 36 of the actuating arms 35, so that the pivoting arms 28, 29 pivot when the plunger cylinder 7 moves towards the

  high, against tension spring 34. The half

  shells 25, 26 pivot towards one another and receive the plunger cylinder 7. During the final phase of lifting the plunger cylinder 7, the pivoting arms 28, 29 can move upwards against the springs of compression 33 in the oblong guide holes 32, so as to guarantee perfect centering of the discharge cap 27 relative to the plunger cylinder 7, regardless of the precise position of the upper end of the stroke of the plunger cylinder 7. On the entire circumferential zone of the zones 38 in the form of a cylindrical sector and of the sectors 37 in the form of a funnel, ie over a circumferential angle of approximately 300 in the example described, the cap 27 is applied against the circumferential surfaces 13 of the walls front 11, 12 and also against the outer surfaces 16 of two support strips 15. The two sectors 37 in the form of a funnel are

  also tightly connect against each other.

  A blower 47 is connected to a half-shell 25 by means of a pipe 46, by means of which, when the discharge cap 27 is closed around the plunger cylinder 7, air is injected according to the arrows 48 and an overpressure is established in the closed discharge cap 27. The air enters, in this case, only in an upper zone in the plunger cylinder 7 due to the described sealing ratios, which zone extends to a maximum of 180. This zone is therefore normally above the parts 42. The air flow is forced through the parts 42 because the lower edge 49 of the slope 44 is always above the most support strip. lower 15, which is still in sealed contact against the associated half-shell 25. This is the half-shell 25 on which the support rods 15 of the plunger cylinder 7 move downward in the direction of rotation. In particular, the zone 38 in the form of a cylindrical sector of this half-shell 25 should extend far enough downwards so that no free space is formed between the lowest support strip 15 still being applied against the half-shell. shell and the lower edge 49 of the slope 44. The air carries most of the liquid adhering to the parts and lets this liquid drip into

  container 2. Even though air may escape briefly at-

  above the slope 44 due to the rotation of the plunger cylinder 7, this leads to jerky operation

  promoting the recovery of liquid.

Claims (8)

  1. Device for recovering liquids (3) adhering to loose parts (42), comprising: a rotary plunger cylinder (7) receiving the parts (42), which consists of front walls (11,12) provided with surfaces cylindrical circumferentials (13) and a cylinder casing (14) having holes (18) disposed between the front walls (11,12); a container (2) for the liquid (3), in particular for a galvanic or chemical treatment bath in the wet phase or for a rinsing bath; a lifting device (8) receiving the plunger cylinder (7) for moving the plunger cylinder (7) from a lower position in the container (2) to an upper position above the container (2); rotary drive means for the plunger cylinder (7); a blowing discharge dome (27) associated with the upper position of the plunger cylinder (7), and comprising two half-shells (25, 26) movable relative to each other in a substantially horizontal manner, the plunger cylinder (7) can be inserted from below between the half-shells (25,26) when the half-shells (25,26) are in a position where they are spaced from one another, the half-shells ( 25, 26) can be applied against the plunger cylinder (7); and a blower (47) connected to the blowing exhaust dome (27), characterized in that the half-shells (25,26) are mounted on pivoting arms (28,29) which can pivot one towards the other when introducing the plunger cylinder   (7) between the half-shells (25,26).   2. Device according to claim 1, characterized in that the lifting device (8) of the plunger cylinder (7) is mechanically coupled to the pivoting arms (28,29) so that they can pivot towards each other during of the final phase of the upward movement of the plunger cylinder (7). 3. Device according to claim 2, characterized in that actuating arms (35) are connected to the pivoting arms (28,29), actuating arms being applied against abutment surfaces (45) provided on the device elevator (8) during the final phase of the movement of the upward plunging cylinder (7).   4. Device according to claim 2 or 3, characterized in that the pivoting arms (28,29) are   biased by a spring (34) tending to separate the half shells (25,26).   5. Device according to one of claims 1 to 4,   characterized in that the pivoting arms (28,29) are arranged to be movable in the direction of elevation of the plunger cylinder (7).   6. Device according to one of claims 1 to 5,   characterized in that the blowing exhaust dome (27) is applied in a sealed manner against the surfaces   circumferential (13) of the front walls (11,12).   7. Device according to one of claims 1 to 6,   characterized in that the half-shells (25, 26) comprise zones (38) in the form of cylindrical sectors applying   tightly against the casing (14) of the cylinder.   8. Device according to claim 2 or 3, characterized in that the pivoting arms (28,29) are biased by at least one counterweight tending to spread the half-shells (25,26).