METHOD FOR RECOVERING INDUSTRIAL TANKS AND APPARATUS

THEREFOR DESCRIPTION Field of the invention

The present invention relates to a method for recovering industrial tanks.

In particular, the invention relates to a method for grinding plastic composite IBCs arranged to contain liquid of various type.

Furthermore, the present invention relates to a cutting machine for carrying out a step of this method.

Description of the prior art As well known, the industrial tanks for containing liquid normally comprise:

- a pallet in wood, plastic or aluminum which acts as support and attachment for handling the tank;

- an intermediate bulk container (IBC) of high density polyethylene that contains the liquid;

- an aluminum cage that protects the plastic composite IBC from possible damages.

Liquids contained in the tank are often of industrial type and have consistency very viscous, causing to be very difficult the cleaning of plastic composite IBC. For this reason, tanks are reconditioned, by removing the pallet and the cage, which are reused, and grinding and cleaning the IBC, in order to recycle the plastic.

Normally, the process of grinding the IBC is carried out by a crusher mill that reduces the IBC in recyclable plastic splinters. However, often in the IBCs remain residuals of industrial liquids which greatly degrade the quality of the produced plastic splinters.

For this reason, upstream of the grinding step, a step can be provided of cutting the IBC in 6 planar portions, corresponding to 6 sides of the IBC itself. This way, in addition to allow a more accurate cleaning and a better removal of the liquid contained, it is reduced also the volume of the IBC, assisting its storage and the manual handling before the grinding.

Generally the cutting step is carried out manually by a human operator. However, given the extreme care and precision required, the operator must be very experienced, increasing the overall process cost. Furthermore, as the operation is carried out in safety, they happen sometimes accidents due to carelessness or to human error. Furthermore, to keep the due security schemes, the cutting speed is lower than that of the final crushing by the mill, reducing the whole process efficiency.

In US6114401 is described a process for recovering plastic IBCs obtainable in an automatic way. In particular, the process provides a cutting phase of the IBC by a cutting machine comprising an electric saw, obtaining parts of plastics, and a washing step of such parts.

However, the process described by this document is not adapted to the industrial tanks above said, since it does not provide steps for removing the pallet wood and the metal cage.

Furthermore, the cutting step made by the electric saw does not provide a cutting pattern that allows to optimize the final volume of the derived parts of plastic, or to assist the next cleaning step.

Summary of the invention

It is therefore a feature of the present invention to provide a process for recovering industrial tanks that provides plastic material of high hygienic quality.

It is also a feature of the present invention to provide such a process that is much quicker and more efficient with respect to processes that use a manual cutting of IBCs.

It is still a feature of the present invention to provide such a process that ensures total safety of use by human users .

These and other objects are achieved by a process for recovering industrial tanks comprising the steps of:

- prearranging a tank to recover, said tank comprising :

- a plastic composite IBC arranged, in use, to contain liquid, said IBC having parallelepiped shape and comprising a bottom face, a top face and four side walls;

- a pallet arranged to support the plastic composite IBC;

- a cage arranged to wrap the plastic composite IBC;

- removing the cage and the pallet;

- cutting the plastic composite IBC obtaining planar portions ;

- cleaning the planar portions from possible residuals of the liquid;

- grinding the planar portions obtaining a plurality of residual scales of plastic composite;

said cutting phase of the plastic composite IBC being carried out by a cutting machine, said cutting machine comprising at least one electric saw arranged to cut the plastic composite IBC,

whose characteristic is that the cutting step comprises the steps of:

- arranging the plastic composite IBC in the cutting machine ;

- horizontal cutting along a curve γι joining the bottom face with the side walls;

- vertical cutting along curves λ joining the side walls;

- horizontal cutting along a curve Y ₂ joining the top face with the side walls.

In this way, there are significant improvements in terms of security for operators compared to the manual carrying out of the cutting step, since you avoid possible accidents due to the hurry or to the difficult maneuverability of the IBC owing to its volume.

Furthermore, there are significant advantages in terms of process efficiency, since it increases both the speed of the cutting phase, both the quality of the finished product.

Advantageously, the cutting step also comprises the steps of:

- locking the plastic composite IBC by a gripper;

- rotating the plastic composite IBC by the gripper, said rotation arranged to assist the steps of horizontal cutting along the curves γι and Y ₂ .

According to another aspect of the invention, it is claimed a cutting machine for cutting a plastic composite IBC, said plastic composite IBC having parallelepiped shape and comprising a bottom face, a top face and four side walls, said cutting machine comprising:

- an insulating cabin comprising at least one access door;

- at least one electric saw internal to the insulating cabin and arranged to cut the plastic composite IBC;

- a gripper arranged to fasten and move the plastic composite IBC in the insulating cabin in order to assist the cutting of the plastic composite IBC; whose main feature is that the cutting machine comprises :

- at least one horizontal electric saw arranged to cut the plastic composite IBC along horizontal curves γι,γι)

- at least one vertical electric saw arranged to cut the plastic composite IBC along vertical curves λ.

Advantageously, the gripper is adapted to rotate the plastic composite IBC to allow said or each horizontal electric saw to cut the plastic composite IBC along horizontal curves γι,Υ2·

In particular, the insulating cabin comprises:

- an area of inlet having a first access door, said area of inlet comprising a first horizontal electric saw arranged to cut the plastic composite IBC along a horizontal curve γι joining the bottom face with the side walls;

- an area of outlet having a second access door, said area of outlet comprising:

- four vertical electric saws arranged to cut the plastic composite IBC along four vertical curves λ;

- a second horizontal electric saw arranged to cut the plastic composite IBC along a horizontal curve Y2 joining the top face with the side walls. In particular, the gripper is adapted to move the plastic composite IBC between the area of inlet and the area of outlet.

This way, it is possible to cut the bottom face of the IBC in the area of inlet, move the IBC in the area of outlet and cutting the side walls and the top face making them fall far from the bottom face. Thus, the walls and the top face of the IBC, normally much more clean of the bottom face (which instead contains most of the liquid residuals), doesn't enter in contact with the bottom face itself and can be sent directly to the grinding. The cleaning step relates, this way, only the bottom face, ensuring a considerable saving of water and pollutant detergents, in addition to speed up very much the cleaning process.

Advantageously, out of the insulating cabin a control board is located for the control of the cutting machine by a user .

This way, when the IBC is located in the cutting machine, the access doors are closed and the operator can maneuver the cutting machine externally, in total safety. Brief description of the drawings

Further characteristic and/or advantages of the present invention are brighter with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which:

- Fig. 1 shows the process for recovering industrial tanks according to the present invention;

- Fig. 2 shows a perspective view of an industrial tank to recover;

- Fig. 3A diagrammatically shows, in an elevational side view, the cutting machine during the horizontal cutting step along the curve γι;

- Fig. 3B diagrammatically shows, in top plan view, the cutting machine during the horizontal cutting step along the curve γι;

- Fig. 4A diagrammatically shows, in side view, the cutting machine during the vertical cutting step along curves λ;

- Fig. 4B diagrammatically shows, in top plan view, the cutting machine during the horizontal cutting step along curves λ;

- Fig. 5A diagrammatically shows, in side view, the cutting machine during the horizontal cutting step along the curve γ ₂ ;

- Fig. 5B diagrammatically shows, in top plan view, the cutting machine during the horizontal cutting step along the curve Y2;

- Fig. 6A diagrammatically shows, in side view, the cutting machine at the end of the cutting step;

- Fig. 6B diagrammatically shows, in top plan view, the cutting machine at the end of cutting step.

Description of a preferred exemplary embodiment

In Fig. 1 a diagrammatical view 300 is shown of an exemplary embodiment of the process for recovering industrial tanks 100, according to the present invention.

With reference to Fig. 2, a tank 100 comprises a plastic composite IBC 110 arranged, in use, to contain liquid 10, a pallet 120 and a cage 130. In particular, the IBC 110 has a parallelepiped shape and comprises a bottom face 110a, a top face 110b and four side walls 110c.

According to the process diagrammatically shown in Fig.

1, firstly is arranged an IBC 110 to recover [301] from which are removed the pallet 120 and the cage 130 [302] . Then begins the cutting phase of the IBC 110 from which are obtained six planar portions 115.

In particular, with reference even at Figs. 3A, 3B, 4A,

4B, 5A, 5B, 6A, 6B, this cutting step is carried out by a cutting machine 200 and it is structured in more steps.

The IBC 110 is at first located in the insulating cabin 210, in particular in the area of inlet 215 [303], and it is then fastened by the gripper 240 [304] . The gripper 240 puts then in rotation the IBC 110 whereas a first horizontal electric saw 220 cuts the IBC 110 itself along a horizontal curve γι joining the bottom face 110a with the side walls 110c [305] .

The gripper 240 then lifts the IBC 110 leaving on the ground the bottom face 110a, which normally contains most of the liquid residuals 10. The gripper then moves the IBC 110 until it is in the area of outlet 216, where it is carried out the vertical cutting step wherein four vertical electric saws 230 cut the IBC 110 along four vertical curves λ, corresponding roughly to the edges between the side walls 110c [306] .

Again the gripper 240 puts in rotation the IBC 110 whereas a second horizontal electric saw 220 cuts the IBC 110 itself along a horizontal curve Y ₂ joining the top face 110b with the side walls 110c [307] .

At the end of the cutting step, 6 planar portions 115 are obtained, corresponding roughly to the bottom face 110a, to the top face 110b and to 4 side walls 110c.

As shown in Figs. 6A and 6B, the side walls 110c and the top face 110b fall on the ground of the area of outlet 216, whereas the bottom face 110A remains on the ground of the area of inlet 215. This way, the side walls 110c and the top face 110b, normally cleaner, can be sent directly to the step of grinding, whereas the bottom face 110A can be clean separately by an easy water jet or other cleaning liquid [308] . The cleaning step is therefore much quicker and efficient with respect to a recovery process that uses a manual cutting by an operator, ensuring a final product of higher quality and a use of a very small amount of both water and polluting cleaning products.

The planar portions 115 thus obtained are finally sent to a mill for the grinding and the reduction in slivers of clean plastic, which can be then being used as secondary raw material for being then recycled [309] .

The foregoing description some exemplary specific embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt in various applications the specific exemplary embodiments without further research and without parting from the invention, and, accordingly, it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention, it is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.