GB2041776A - Self-propelled unit for the collection and recycling of grinding sludges - Google Patents

Abstract

A self-propelled unit for collecting metal-bearing grinding sludge separates the sludge into solid, metal-bearing material and oily liquid residue while in transit, thereby facilitating the recycling of such sludges, rather than their disposal. The unit is mounted on a vehicle (1) and includes a hopper (4) for loading the sludge into a squeezing device (3) having a piston (9) which squeezes the liquid into a tank (13) and compacts the solid material. A deflector plate (19) selectively controls the transfer of the solid material from the squeezing device (3) to a respective cell (16, 17) of a collecting drum (15), according to whether the material contains iron or steel. <IMAGE>

Description

SPECIFICATION Self-propelled unit for the collection and recycling of grinding sludges The present invention relates to a self-propelled unit for the collection of grinding sludges.

Grinding sludges, being the waste material formed during grinding operations, are composed essentially of metal fragments, particles of abrasive and residues of an oily liquid, usually mineral oil/water emulsion, which is used as a coolant in grinding operations.

The presence of the oily liquid residues in the huge quantities of grinding sludge produced daily by the engineering industry is an impediment to the recycling of the grinding sludges produced during a production process, and has given rise to considerable problems in the disposal of the sludges. Such disposal is effected by collecting the sludges in special discharge vats to prevent contamination of the soil. This in itself presents problems, however, in view of the ever-increasing difficulties in finding new sites on which to build these vats.

The object of the present invention is to provide a means of alleviating the aforesaid problems, which is compact and facilitates the collection and recycling of grinding sludges.

According to the present invention there is provided a self-propelled unit for the collection of grinding sludges characterised in that the unit comprises a motor-vehicle having a device for squeezing the grinding sludges, comprising a piston which is slidable in a cylinder under the action of operating means, and means which load the grinding sludges into the cylinder for compression by the piston, to squeeze from the sludges an oily liquid, which flows through outlet means into a tank carried by the vehicle, leaving compacted solid material, which is controllably loaded into a collection chamber on the vehicle, the tank and the collection chamber being provided with respective discharge means.

Advantageously, the self-propelled unit according to the invention will repiace the lorries used previously for transporting untreated grinding sludges from the industrial plant to the discharge vats, since it is possible to separate the oily liquid residues from the solid components of the sludges in the collection vehicle. Both the oily liquid and the compacted solid material may then be recycled productively: for example, the compacted solid material being used in the manufacture of briquettes for the iron and steel industry; the oily liquid being reclaimed for reutilisation by the engineering industry.

In a preferred embodiment, the collection chamber for the compacted solid material is subdivided internally to form two separate cells for collecting, respectively, compacted material containing fragments of steel, and compacted material containing fragments of cast iron. The loading of the compacted material into the collection chamber may be controlled by means selectively operable to feed the material to the cell appropriate to the metal content of the grinding sludge collected by said unit.

One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying purely diagrammatic drawings, in which: Figure 1 is a partially cut-away and sectioned side elevational view of a self-propelled unit according to the present invention, for the coliecfion of grinding sludges, and Figure 2 is a partially sectioned plan view of the self-propelled unit of Figure 1.

Referring now to the drawings, there is shown a heavy motor vehicle, generally indicated 1, having a rear body 2 which houses a device 3 for squeezing the grinding sludges, which will be described in detail below. The grinding sludges are supplied to the squeezing device 3 through a loading hopper 4 which has an input opening 4a and a feeder screw 4b. The loading of the grinding sludges into the hopper 4 is achieved by an elevator device known per se and commonly used in lorries which collect urban refuse. In this example, the device comprises a system of levers 5 which are operated by means of a hydraulic jack 6 to grip a container 7 of grinding sludge, raise it to the input opening 4a of the hopper 4, and to tip the container to empty the grinding sludge into the hopper 4.In Figure 1, the gripping position of the container 7 is shown in continuous outline, and the tipping position is shown in broken outline.

The squeezing device 3 comprises, in this example, a cylinder 8 and a coaxially slidable piston 9. The upper wall of the cylinder 8 is provided with an aperture 8a through which the grinding sliudges~are fed from hopper 4. The piston 9 is operated by a hydraulic jack 10, but any other suitable means may be used.

At the opposite end of the cylinder 8 from the piston-operating jack 10 is located a plate 11 which is displaceable in its own plane, that is, perpendicular to the axis of the cylinder 8 (see Figure 2), by means of a hydraulic jack 12. The plate 11 is displaceable between a closure position (shown in continuous outline), in which the plate 11 completely closes the adjacent end of the cylinder 8, and an open position (shown in broken outline), in which material can pass from the cylinder 8 through the adjacent end. In the closure position, there is a slight axial spacing between the plate 11 and the adjacent end surface of the cylinder 8 which defines an outlet 11 a.During operation of the squeezing device 3, the oily liquid which is separated from the grinding sludges can pass through the outlet 1 a and flow into a tank 1 3 arranged below the squeezing device 3. The tank 1 3 is provided with a drain cock 14, for discharging the oily liquid L from the tank.

The front part of the rear body 2 comprises a separate drum member 1 5 which is supported by the fixed structure of the lorry 1 for rotation about a longitudinal axis X-X driven by a hydraulic motor 1 The motor 1 6a can rotate the drum 1 5 in both the clockwise and anti-clockwise directions.

The drum 1 5 is subdivided internally into two separate cells 16, 1 8 (see Figure 2) which are adapted, respectively, for collecting solid components of the grinding sludges containing fragments of cast iron, and solid components of the grinding sludges containing fragments of steel.

The two cells 16, 1 7 communicate, through a passage 1 8, with the end of the cylinder closable by the plate 11.

The passage 18 is provided with a deflector plate 1 9 which is displaceable between two positions, (shown in continuous outline and broken outline respectively, in Figure 2) to put the cylinder 8 into exlcusive communication with one or other of the cells 1 6, 17. In this example, the deflector 1 9 is operated by a hydraulic jack 20.

The wall of the drum 1 5 is provided with a respective aperture 21 for the discharge. of the material from each cell 16, 17. The apertures 21 are closed by flaps when not in use.

The self-propelled unit operates as follows: the lorry 1 is used within the industrial plant producing the grinding sludges to collect containers 7 which have been filled previously with grinding sludges and left at various points around the plant. Each time a container 7 is to be emptied into the unit, the system of levers 5 is operated by the jack 6 to raise the container 7 and tip the grinding sludge into the hopper 4, from where it is fed to the cylinder 8 through the aperture 8a. At this stage, the piston 9 is, of course, kept in the retracted position by its operating jack 10.

When the grinding sludge has been emptied into the cylinder 8, the piston 9.is operated to move towards the plate 11 which is in the closure position, so that the piston 9 squeezes the grinding sludge by compressing them against the plate 11. The oily liquid which is separated from the grinding sludge as a result of this squeezing flows through the passage 1 a into the tank 13.

At this stage, the plate 11 is displaced to the open position by the jack 12, so as to put the cylinder 8 into communication with the cells 1 6, 1 7 of the drum 15. According to whether the grinding sludge contains fragments of steel or cast iron, the deflector plate 1 9 is displaced so as to block off either the cell 1 6 or the cell 17. The forward stroke of the piston 9 is then completed, so that the solid material compacted by the piston 9, during the squeezing stage, is thrust into the corresponding cell 16, 1 7.

All these operations may be conducted whilst the lorry 1 continues to move around the industrial plant collecting grinding sludge from other containers 7.

It is preferable that the lower end of the hopper 4 is provided with a closure element (not shown), to prevent the grinding sludge from falling into the cylinder 8 when the piston 9 is in its forward-most position.

The dily liquid recovered in the tank 1 3 is discharged through the drain cock 14 and may be subjected to a reclaiming process to render it reusable.

The solid material is unloaded from the cells 16, 17, through the apertures 21, by rotating the drum 1 5 and may then be used, for example, as an ingredient of briquettes for the iron and steel industry.

Claims (9)

1. A self-propelled unit for the collection of grinding sludges, comprising a motor vehicle having a device for squeezing the grinding siudges, comprising a piston which is slidable in a cylinder under the action of operating means, and means which load the grinding sludges into the cylinder for compression by the piston, to squeeze from the sludges an cily liquid, which flows through outlet means into a tank carried by the vehicle, leaving compacted solid material, which is controllably loaded into a collection chamber on the vehicle, the tank and the collection chamber being provided with respective discharge means.

2. A self-propelied unit as claimed in Claim 1, in which the collection chamber for the compacted solid material is subdivided internally to form two separate cells for collecting, respectively, compacted material containing fragments of steel, and compacted material containing fragments of cast iron, and in which the loading of the compacted material into the collection chamber is controlled by means selectively operable to feed the material into the cell appropriate to the metal content of the grinding sludge collected by said unit.

3. A self-propelled unit as claimed in Claim 1, in which one end of the cylinder of the squeezing device is provided with a plate which is displaceable, in a plane perpendicular to the axis of the cylinder, between a closure position, which completely closes said end of the cylinder to permit the grinding sludges to be compressed against said plate by the piston, and an open position, which allows the solid material compacted by the piston to be fed into the collection chamber.

4. A self-propelled unit as claimed in Claim 3, in which the outlet means allowing the separated liquid to pass into the tank comprises a passage defined by an axial spacing between said end of the cylinder and said plate.

5. A self-propelled unit as claimed in Claim 1 , in which the means for loading the grinding sludge into the cylinder comprise a hopper, with a feeder screw arranged therein, and an elevator device for loading the grinding sludge into the hopper.

6. A self-propelled unit as claimed in Claim 2, in which the selectively-operable means controlling the loading of compacted material into said collection chamber comprise 3 deflector plate which is displaceable between two positions, each position allowing material to be fed to a respective said cell.

7. A self-propelied unit as claimed in Claim 2, in which the collection chamber is defined by a drum member, the wall of which is provided with a respective aperture for unloading each of the cells, the drum being supported by the fixed structure of the vehicle for rotation about a longitudinal axis, and in which drive means are provided for rotating the drum in either direction of rotation, to facilitate unloading of the cells.

8. A self-propelled unit as claimed in Claim 1, in which the tank is provided with a drain cock.

9. A self-propelled unit for the collection of grinding sludges, substantially as herein described with reference to, and as shown in, the accompanying drawings.