FR3145301A1 - Sludge treatment system, particularly for sludge from the cutting of optical glasses. - Google Patents

Abstract

The invention relates to a system (1) for treating charged water produced by a grinder (8), comprising a settling tank (23), a rotating filter (26) immersed in the water of this tank, means (11) for bringing the charged water from the grinder into the tank and means (12, 40, 46, 15, 16) for taking filtered water from inside the filter and for bringing it to the grinder. Figure for abstract: figure 2.

Description

Sludge treatment system, particularly for sludge from optical glass cutting.

The present invention relates to the field of glass grinding, in particular optical glass and particularly spectacle lenses. Such glass may be mineral glass, or not.

Eyeglass lenses are cut to order, using machines called grinders. Grinding requires water spraying to remove the calories and particles of glass or plastic generated during this operation. Grinding, as it is currently carried out, requires significant water consumption and pollution by the particles it generates. The use of a closed circuit, which would be likely to save water, is very restrictive; it requires frequent interruptions and therefore does not allow continuous production of lenses and generates bad odors. It is therefore the use of water in an open circuit that is preferred, with water loaded with particles being discharged into the collective wastewater network.

The aim of the invention is to propose a solution that saves water, while limiting the release of particles from grinding operations.

According to the invention, such a system for treating loaded water, in particular water produced by a grinder, comprises a settling tank for collecting this water, a rotating filter immersed in the water in the tank, means for bringing the loaded water from the grinder into the tank and means for taking filtered water from inside the filter and bringing it to the grinder.

The filter preferably comprises a solid disc-shaped bottom, a cylindrical filter wall around a substantially vertical axis of rotation of the filter and rising upwards from a peripheral edge of the bottom, and a shaft extending along this axis of rotation.

The system may also include a tank having, at its substantially lowest level, an opening which connects the interior of this tank with the interior of the bin, the filter being arranged inside the tank.

Advantageously, the system includes a removable bag to contain the water in the tank.

It may further include means for spraying a surface of the water in the tank with water taken from the filter.

Advantageously, the system comprises a ramp for diffusing ultraviolet light, arranged inside the tank, preferably inside the filter.

Preferably, the means for drawing filtered water from inside the filter comprise a pipe which is immersed in the water in the filter and, in line with this pipe, a pump and an exchanger, preferably an air/water exchanger, for cooling the water thus drawn.

Such a system can also include a drawer on which the tray is placed.

Advantageously, the system fits into a cube with each edge measuring fifty centimeters on each side maximum.

The invention also relates to a machine for grinding optical glasses, which comprises a grinder and a processing system according to the invention.

In such a machine, the grinder may comprise a grinding wheel and a trough for collecting the grinding water, and form a closed circuit for the water in which the means for bringing the loaded water from the grinder into the tank comprise a pipe which connects the trough to the tank, this circuit further comprising means for watering the trough with water taken from the filter and means for watering the grinding wheel with water taken from the filter.

Several embodiments of the invention will be described below, by way of non-limiting examples, with reference to the appended drawings in which:

is a schematic and three-quarter right perspective view of a water treatment system according to the invention intended to equip an optical glass grinding machine;

is a block diagram of an optical glass grinding machine equipped with the processing system of the ;

is a schematic and cross-sectional view of the water treatment system of the ;

is a schematic, perspective view from the right of the water treatment system of the ; And,

is a schematic, perspective front view of the water treatment system of the , with some of its components being presented separately from the rest of the system.

The figures illustrate a system 1 according to the invention for treating water from a grinding machine 10. The system 1 comprises a hydraulic box 2 and a filtration system 3. In the example illustrated, the system 1 further comprises a frame 4 provided with a horizontal plate 6 and a separator 7 extending vertically from the plate. The box 2 and the treatment system 3 are arranged on the plate, each on a respective side of the separator 7.

There illustrates a grinding machine 10 which comprises the system 1 and a grinder 8. The grinder 8 comprises a grinding wheel 18 arranged in a trough 19. The trough makes it possible to collect water laden with sludge produced by grinding operations.

The treatment system 1 comprises a tank 21 provided with a cover 22. In a usage configuration, such as that illustrated in particular in , the system comprises a flexible, removable and disposable bag 23, which lines the inside of the tank; the edges of the bag are kept pinched between the tank 21 and its cover 22. In a functional state, illustrated in , the water is maintained in the tank at an ordinary level within a given interval and noted N at the .

The cover 22 serves as a support for several treatment equipment 24-27, in particular a sieve 24, a sprinkler 25, a filter 26, and an ultraviolet ramp 27.

The filter 26 is arranged in a tank 31 carried by the cover 22 and immersed in the container 21; an annular upper edge 31A of the tank rests on the cover 22. The tank comprises, at its lowest level and below the water level N, an opening 32 which connects the interior of the tank with the interior of the container 21.

The filter 26 comprises a cylindrical filter wall 33 and a solid disk-shaped bottom 34. The bottom is arranged below the ordinary level N, in the vicinity of the opening 32 of the tank. The filter wall 33 rises upwards from the peripheral edge of the bottom 34 to above the ordinary level N. The filter further comprises a vertical shaft 36 extending from the bottom 34 upwards along an axis X26 of the filter.

The filtration system 1 also comprises a motorization and control housing 37. The housing 37 comprises a motor 38 and control means for the treatment system. The motor 38 and the shaft 36 comprise reciprocal engagement means 39; the motor is provided to drive the filter in rotation about the filter axis X26. The housing 37 rests on the annular edge 31A of the tank; this edge serves to center the housing, and therefore the filter relative to the tank 31.

The ramp 37 is fixed under the housing 37 so that it extends downwards inside the filter and, at least, substantially over the entire submerged height of the filter wall 33. The ramp 37 is designed to diffuse type C ultraviolet rays. This radiation is intended to kill the bacteria that develop in the water in the tank; this eliminates unpleasant odors. Indeed, the ambient temperature, the increase in the temperature of the water due to the grinding of the glass and the mixing of this water with the cutting waste promote the appearance of bacteria. The destruction of the bacteria makes the work of the operators who handle the equipment and the glasses, thus free of bacteria, safer.

• un premier tuyau 11, pour amener de l’eau chargée de boues de meulage, issue de la meuleuse 8, depuis l’auge 19 jusqu’au tamis 24 ;
• un deuxième tuyau 12, pour extraire de l’eau filtrée depuis le filtre 26 ;
• un troisième tuyau 13 pour alimenter l’asperseur avec de l’eau filtrée; et,
• un quatrième tuyau 14, permettant de vidanger le système de filtration 3.

As particularly illustrated in Figures 2 and 4, the system 1 further comprises a set of pipes 11-16 for connecting the hydraulic box 2 and the treatment system 3 to each other and for creating, with the grinder 8, a closed circuit 40 for grinding water. The pipes comprise:

• a first pipe 11, for bringing water loaded with grinding sludge, coming from the grinder 8, from the trough 19 to the sieve 24;
• a second pipe 12, for extracting filtered water from the filter 26;
• a third pipe 13 to supply the sprinkler with filtered water; and,
• a fourth pipe 14, allowing the filtration system 3 to be drained.

• un cinquième tuyau 15, pour arroser la meule 18 avec de l’eau filtrée, pour la refroidir et la lubrifier ; et,
• un sixième tuyau 16, pour arroser l’auge 19 avec de l’eau filtrée pour faciliter l’évacuation des boues de meulage.

Machine 10 also includes:

• a fifth pipe 15, for watering the grinding wheel 18 with filtered water, to cool and lubricate it; and,
• a sixth pipe 16, for watering the trough 19 with filtered water to facilitate the evacuation of grinding sludge.

The tank 22 allows the decantation of the charged water; the bag 23 is designed to collect the grinding sludge thus decanted. It allows this sludge to be easily removed from the bottom of the tank by removing the bag 23.

The hydraulic box 2 comprises, in the circuit 40, three valves 41-43, an exchanger 45 and a pump 46. The exchanger and the pump are mounted in line on the second pipe 12. The exchanger 45 is an air/water exchanger; it is equipped with a fan 47 to cool the water from the filtration system 3. Thus, this cooling system 45, 47, makes it possible to evacuate the calories accumulated in the water and produced by the grinding operations.

• une première vanne 41 branchée en amont au deuxième tuyau 12 et en aval au sixième tuyau 16 ; elle permet de nettoyer l’auge 19 ;
• une deuxième vanne 42 branchée en amont au deuxième tuyau et en aval au cinquième tuyau 15 ; elle permet de refroidir et de lubrifier la meule 18 ; et,
• la troisième vanne 43, branchée en amont au deuxième tuyau et en aval au quatrième tuyau 14 ; elle permet de vider le bac 22.

Pump 46 supplies the three motorized valves 41-42 with filtered and cooled water. Valves 41-43 include:

• a first valve 41 connected upstream to the second pipe 12 and downstream to the sixth pipe 16; it allows the trough 19 to be cleaned;
• a second valve 42 connected upstream to the second pipe and downstream to the fifth pipe 15; it allows the grinding wheel 18 to be cooled and lubricated; and,
• the third valve 43, connected upstream to the second pipe and downstream to the fourth pipe 14; it allows the tank 22 to be emptied.

The third pipe 13 is connected downstream of the pump 46, so that when the pump is operating, filtered water is sprayed on the surface of the charged water which is in the tank 22, to prevent the formation of foam on its surface. This foam appears on the surface of the water due to the surface tension of the water which has increased due to the presence of cutting particles.

The emptying of the tank is ensured by the third valve 43 in response to an action of an operator on a button 50 of the box 37. This emptying allows, when the bag 23 is full, to remove the residual water from the plastic bag. This residual water is advantageously reused for a next operating cycle of the machine 10.

The filtration system 3 further comprises two probes 48, 49, fixed to the housing 47 and immersed inside the filter 26.

A first probe 48 is a filling probe. It measures the level of water N in the tank when the filter is not running. When the level of ordinary water N is outside a range suitable for the proper functioning of the treatment system 1, it can alert an operator.

The second probe 49 is a fouling probe. It measures the level of fouling of the filter. Indeed, when the filter turns and the pump is in action, a vortex is generated inside the filter. The water level in the filter varies depending on whether the filter is more or less fouled. The second probe is intended to alert the operator when a minimum level is reached. Cleaning of the filter is then required. This second probe 49 plunges deeper into the filter 26 than the first probe 48.

The machine also includes a cable 51 which allows data to be exchanged between the grinder 8, the valves 41-43, the probes 47,48 and the control box 37.

When the pump 46 is operating, the filter 26 is simultaneously rotated about its axis X26. The rotation of the filter has the effect of pushing back the cutting particles which tend to agglomerate on the filter wall 33 of the filter, carried by the circulation of water from the outside to the inside of the filter. This rotation, by pushing back these particles, makes it possible to significantly reduce the frequency of cleaning of the filter.

Box 37 controls the operation of the system and alerts the operator, by a light system and/or an audible alarm, in the event of a request for water level top-up, filter cleaning or operating anomaly.

As particularly illustrated in the , the tray 6 comprises a drawer 61 on which the tank 21 rests. The drawer further comprises lateral wedges 62, here in the shape of a “C”, which ensure lateral support of the tank. Thus, when several treatment systems 1 or several machines 10 are juxtaposed and/or superimposed, the drawer allows access to the filtration system, in particular to change the bag or clean the filter.

Typically, the system 1, as described with reference to the figures, has a height H equal to approximately fifty centimeters, a width L equal to approximately forty centimeters and a depth P equal to approximately forty-five centimeters.

Of course, the invention is not limited to the examples which have just been described.

It will indeed appear to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teaching which has just been disclosed to him.

Thus, depending on the design of the grinder, several water jets may be required operating independently or simultaneously. Thus, the first valve 41 and the second valve 42 may each represent a system of more motorized valves performing their functions.

Also, the same water treatment system can supply several millstones.

Such a grinding water treatment system makes it possible to significantly reduce water consumption and particle pollution induced by grinding; the latter are not sent directly into the wastewater network. The grinding sludge is collected in a plastic bag; the operator simply has to remove the plastic bag from the tank. This bag is then advantageously treated in plastic recycling or energy recovery.

The treatment system according to the invention is automated so that it offers operators great comfort of use. The grinder is always clean, the water filtration level is controlled, and the production quality is constant.

Also, a system according to the invention can be adapted to treat water loaded with particles coming from other sources. For example, this system can be used to treat water coming from other machine tools such as a lathe or a milling machine. It can also be adapted to the treatment of water from a natural swimming pool, otherwise called artificial swimming.

Claims (10)

System (1) for treating water loaded with particles produced by a grinder (8), characterized in that it comprises a settling tank (21), a rotating filter (26) immersed in the water of said tank, means (11) for bringing the loaded water from said grinder into said tank and means (12, 40, 46, 15, 16) for taking filtered water from inside said filter and bringing it to the grinder. System according to claim 1, characterized in that the filter comprises a solid bottom (34) in the form of a disc, a cylindrical filtering wall (33) around a substantially vertical axis of rotation (X26) of the filter and rising upwards from a peripheral edge of said bottom and a shaft (36) extending along said axis of rotation. System according to claim 2, characterized in that it comprises a tank (31) comprising, at its substantially lowest level, an opening (32) which connects the interior of said tank with the interior of the bin (21), the filter (26) being arranged inside said tank. System according to one of claims 1 to 3, characterized in that it comprises a removable bag (23) for containing the water in the tank. System according to one of claims 1 to 4, characterized in that it comprises means (25) for spraying a surface of the water in the tank with water taken from the filter (26). System according to one of claims 1 to 5, characterized in that the means for taking filtered water from inside the filter, comprise a pipe (12) which is immersed in the water in said filter and, in line with said pipe (12), a pump (46) and an exchanger (45), preferably an air/water exchanger, for cooling the water thus taken. System according to one of claims 1 to 6, characterized in that it comprises a ramp (27) for diffusing ultraviolet light, arranged inside the filter (26). System according to one of claims 1 to 7, characterized in that it fits into a cube of which each edge (H, P, L) measures fifty centimeters on a maximum side. Machine (10) for grinding optical glasses, characterized in that it comprises a grinder (8) and a treatment system according to one of the preceding claims for treating the grinding water. Machine according to claim 9, characterized in that the grinder (8) comprises a grinding wheel (18) and a trough (19) for collecting the grinding water, and in that it forms a closed circuit for the water in which the means (11) for bringing the loaded water from said grinder into the tank (21) comprise a pipe which connects said trough to said tank, this circuit further comprising means (41) for watering the trough with water taken from the filter and means (42) for watering the grinding wheel with water taken from the filter.