A METHOD FOR TREATING GARBAGE AND A DEVICE FOR PERFORMING THE METHOD

Abstract: In a device for treatment of such comparatively solid waste, which at purification plants accompanies the waste water that shall be purified, such waste is transported up to a plant (1) incorporating a cylinder (2) in which the waste is introduced via a hopper (9). By means of a feed piston (3) arranged displaceably in the cylinder the waste is moved towards a counterstay shaped as a displaceable wall portion (11) and is thereby compacted. Through nozzles provided in the end of the feed piston (3) water is injected under high pressure in the waste and this water like the liquid pressed out at the compacting of the waste, leaves the cylinder via grooves or channels (15) provided in the wall portion (11). After completed compacting the wall portion (11) is moved away and the compacted and purified waste is discharged from the cylinder.

Description: The present invention refers to a method and a device for treating such, comparatively solid waste that accompanies waste water, which for purification flows through a chute or the like to a purification plant. Background of the invention It is earlier known by means of elements projecting down into such a chute to catch solid waste and to transport it from the chute, which waste is thereupon subjected to a pressing operation for removal of the water The residual products that have been pressed out often contain fæces, which results in that these waste products are very nasty-smelling, bacterious and unpleasant to handle. Such prior art is described in EP-A-0 244 765. Purpose and most essential features of the invention The purpose of the invention is therefore first to remedy these inconveniences and to provide an automatic process for treatment of waste of the above mentioned type in such a manner that the solid waste as far as possible can leave the plant for further destruction or for other treatment, whereas the biologically destructable products may be brought back to the waste water. These tasks have been solved by the method of claim 1. The invention also refers to a device for accomplishing the method and having the features defined in claim 2. Description of the drawings In the accompanying drawings is shown an embodiment as an example of the invention, whereby the drawings schematically show a plant for treatment of the waste transported in the manner mentioned above and where the different drawing figures illustrate different steps of the treatment process. Fig. 1 thereby shows schematically and partially in section a plant according to the invention in a ready position, Fig. 2 shows the same plant but in a treatment step, where a certain compression of the waste has been made and where water under high pressure is forced through it, Fig. 3 shows the plant according to Fig. 1 and Fig. 2 but at termination of the compression step, and Fig. 4 finally shows the plant after completed compression and in position for feeding out the treated waste from the plant. Description of the invention Such as mentioned in the introduction the invention refers to a method and a device for further treating such a mainly solid waste, which shall not be fed to the very purification plant and which therefore before reaching this is caught and conveyed up to the plant shown in the drawings. As the invention does not concern the catching or conveying of the waste and as devices for such purpose are earlier known, that part of the process will not be further described. It shall only be mentioned that such devices generally comprise some member, which may be lowered into the chute, and through which the waste water may pass, but not the solid waste here concerned. This member is further combined with a conveyor, e.g. a bucket chain, which conveys the collected waste to the device shown in the drawings, which in the figures have been given the general designation 1. At the embodiment shown the plant incorporates a compactor 1 formed as a cylinder 2, in which is displaceably arranged a feed piston 3, which as can be seen in fig. 1 is tubular, thus that it can house a pressure medium actuated cylinder 4, which at 5 is articulatedly connected to the rearmost end of the compactor cylinder 2. The piston bar of the cylinder 4 is at 6 articulatedly connected to the feed piston 3. Through this extends one or more channels, which terminate with nozzles 7 opening in the end surface of the feed piston 3. At the upper side of the compactor cylinder 2 is connected a feeding portion 8, which has a preferably hopper-formed opening 9, through which the waste is introduced into the cylinder 2. To the cylinder 2 is further connected a chamber 10 arranged perpendicularly thereto in which is displaceably arranged a slide 11, which has a wall portion 11' with a shape and size adapted so to the cross section of the cylinder 2, that it covers the through opening of the cylinder when the slide 11 is in the positon shown in fig. 1 A cylinder 12, which is actuated by pressure medium, is at 13 articulatedly connected to an attachment in the chamber 10 and the piston bar 14 of the cylinder is articulatedly connected to the slide 11. In the wall portion 11' thereof is provided a number of channels or grooves 15, which communicate with openings 16 situated outside the compactor cylinder 2. 17 designates a high pressure pump formed as a piston pump, incorporating a cylinder 18 with a tandem piston 19, which is displaceable, on one hand in the cylinder 18, and on the other hand in a pressure medium actuated cylinder 20. Through a conduit 21 provided with a non-return valve 23 the cylinder 18 is connected to a water reservoar 22 and from the cylinder 18 extends a conduit 24 provided with a non-return valve 23, which is in direct connection with the channel or those channels in the feed piston 3, which lead to the nozzles 7. By means of actuators known per se the now described pressure medium actuated units are acutated in such a manner that the operation processes, which will now be described, can be accomplished automatically. In the position of the active members shown in fig. 1, these members can be defined as situated in an inactive ready position. In this position the feed piston 3 is retracted thus, that waste can fall down freely into the compactor cylinder 2 via the hopper-formed opening 9. The cylinder 4, which is double acting, thereby has its piston bar in a retracted position. The piston bar of the cylinder 12, which is likewise double acting, is however in extended position, whereby the slide 11 separates the compactor cylinder 2 from a pipe socket formed as an extension of the cylinder. The cylinder 19, which also is double acting has its piston bar withdrawn, whereby also the piston 18 is in its retracted position in the cylinder 17. This is filled with water, which has earlier been sucked up from the water reservoar 22. As the non-return valves 23 are adapted to open for flow upwards in Fig. 1 but to block flow in opposite direction, it is understood that the sucking up of water is effected at the movement of the piston 18 to the right in the figure, whereas the water under pressure flows through the conduit 24, when the piston 18 moves in opposite direction. According to fig. 2 the feed piston has moved the waste introduced through the opening 9 in a direction against the slide 11, by activating the cylinder 4. In this connection it should be mentioned that the cylinder 4 and its piston bar never will come in contact with the waste or the waste water, which has accompanied this as the cylinder 4 acts inside the feed piston 3, which last-mentioned therefore must stand all contact with the waste and the water. As the slide 11 is situated in its lowermost blocking position, it is evident that the waste, during this feed movement, has been compressed to some extent. Simultaneously with this pressing movement the cylinder 20 is activated, whereby the piston 19 under high pressure presses water via the conduit 24 and the channels in the feed piston 3 to nozzles 7 under generation of strong water jets. The waste will thereby be washed, which means, that the main part of the nasty-smelling matters present in the waste, will be mixed with the water and be displaced with this. Such as earlier mentioned the wall portion of the slide 11 has a number of channels, grooves or the like 15, through which the water is distributed to the openings 16 from which it is brought back to the chute, which leads the water to the purifying plant. At the following compression of the waste the piston 3 of course can make a number of reciprocating strokes in order to collect a bigger quantity of waste whereby is effected, depending on the circumstances, such as the nature of the material and the amount of compacting, a more or less dry and rather solid consistency of the press-cake formed from the waste residuals. In fig. 4 is shown a situation where the cylinder 12 is in its raised position thus that the passage to the adjoining pipe socket is free. For terminating an operation cycle cylinder 4 is then again actuated, thus that the feed piston 3 can continue its movement to the left, thus that the compressed waste mass B is moved past the chamber 10, where it bumps into a mass A which has been compacted during an earlier operation cycle. The waste mass which leaves the cylinder 2 has mainly lost its nasty-smelling tone and can be in form of a stiff cake or be formed as briquettes, which can be supplied to a destruction plant, e.g. an incineration station or be taken care of in another manner. It is evident that the steps now described in a operation cycle can be distinct or more or less successively change over into each other. Compression and water injection can be performed several times within the same cycle. In practice the supply of waste takes place from the chute generally at non-regular intervals and with varying quantities. It can then be chosen to let the operation cycle start first after the part of the cylinder 2 situated between the feed piston 3 and the wall portion 11 in fig. 1 is entirely or partly filled with waste or it is possible to let the feed piston make several strokes for successively forwarding the waste prior to the performing of the actual compression step. For this purpose is of course used conventional sensing and actuating means. Instead of the feed piston 3 which is displaceable in the cylinder 2 it is possible to use a compacting screw, e.g. of the type which nowadays is used for injection moulding of thermal plastic materials. Beside or instead of the nozzles 7 provided at a feed piston for injection of water it is also possible to effect a water injection through the part of the cylinder wall 2 which is situated between the feeding part 8 and the slide 11. At least one of the channels 15 should extend outside the cylinder for discharge of the liquid. It is also possible to open and close the channels 15 and/or the openings 16 alternatingly for obtaining a chock-formed liquid through flow. Such a chock-formed effect can of course also be obtained by corresponding control of the cylinder 19 or by particular valve provisions. The wall portion 11' can also consist of a rotatable disc or the like provided in slots in the cylinder, and which in turn can have nozzles 7 connected to the high pressure pump 17. It is evident that the operation process with conventional means can be made entirely automatic.

Claims: A method for treating residues in waste water containing solids and biologically destructible products, wherein said waste water residues are compressed and dewatered in a compacting and dewatering plant (1), characterized in, that after or simultaneously with the compression of the waste water residues to remove part of its liquid content, water under high pressure is forced through the compressed waste water residues to wash the solids therein and to carry along the main part of the biologically destructible products, leading the washing liquid with the biologically destructible products mixed therewith to a waste water purification plant, and further compressing said compressed waste water residues to give off the main part of its liquid content. A device for treating residues in waste water containing solids and biologically destructible products according to the method claimed in claim 1, said device comprises a cylinder (2) having a preferably hopper-shaped feeding-in part (8) for feeding said waste water residues into the cylinder (1) and a compacting member (3) displaceable in said cylinder and being arranged to compress said waste water residues introduced into the cylinder against a wall portion (11) which is displaceable from an active position, in which it mainly covers the cylinder cross-section and act as a counterstay for said compacting member (3), to an inactive position in which it is moved out of the cylinder, characterized in, that in said cylinder there is provided at least one nozzle (7) or opening communicating with means (17) for supplying water under high pressure and forcing it through the waste water residues to wash the solids therein and to carry along the main part of biologically destructible products. A device as claimed in claim 2, characterized in, that the compacting member consists of a feed piston (3) displaceably arranged in the compacting cylinder (2), which piston in is end surface has at least one nozzle (7), through which water is sprayed into the cylinder. A device as claimed in claim 2, characterized in, that the displaceable wall (11) forms part of a slide (11a), which is displaceable perpendicularly to the cylinder. A device as claimed in claim 2, characterized in, that the displaceable will (11) in its end surface facing the compacting member (3) has a number of grooves or channels (15) of which at least one extends outside the cylinder (2) for liquid discharge from the cylinder. A device as claimed in claims 2 or 3, characterized in, that the feed piston (3) has a stroke length exceeding the axial length of the opening (9) of the feeding-in-part (8) so much, that the feed piston covers said opening during its entire compacting and feeding-out stroke, and that said cylinder (2) has an internal axial space having such dimensions that the pressure medium actuated cylinder-piston unit (4) can be housed therein for the displacement of the feed piston.

Inventors: WALLANDER, CARL OTTO
Applicants: HYDROPRESS WALLANDER & CO AB
Application year: 1988
Main classification: B30B9
IPC codes: E03F5, B30B9