Title of Invention

"A DEVICE FOR REMOVING LIQUID FROM A MIXTURE OF LIQUID AND SOLID MATTER"

Abstract A device for removing liquid from a mixture of liquid and solid matter, provided with an endless conveyor belt (28) which is previous to liquid and with one or more casings (29) over which a conveying portion of the conveyor belt (28) moving the mixture during operation is led, whereby means are provided for intermittently effecting a relative movement between the casings (29) and the conveyor belt (28) and a relative standstill between the casings (29) and the conveyor belt (28), as well as means (5-7) for generating a sub-atmospheric pressure in said casings (29) during the periods when the conveyor belt (28) and the casing(s) (29) do not move with respect to each other, characterized in that a plurality of pressure rollers (9) extending transversely to the direction of movement are disposed above a conveying portion of the conveyor belt extending over a casing (29) having a fixed position, whilst means are provided by which said pressure rollers (9) can be independently pressed down in the direction of the conveying portion and be moved in a direction away from the conveying portion.
Full Text The invention relates to a device for removing liquid from a mixture of liquid and solid matter, whereby the mixture is led over one or more casings by means of a conveyor belt which is pervious to liquid, whreby during operation first periods, in which said casing(s) and said conveyor belt are stationary with respect to each other and in which a sub-atmospheric pressure is maintained in said casing(s), are alternated with second periods in which a relative movement between the conveyor belt and the casing(s) is effected and the pressure in the casing(s) is kept at that of the surrounding atmosphere.
From FR-A-2,194,466 there is known a device which while being satisfactory by itself, there are a number of cases where it may be desirable to effect an even better removal of liquid from a mixture of liquid and solid matter.
By using the device according to the present invention a particularly effective removal of liquid from the mixture can be obtained during the periods when the casing(s) and the belt are stationary with respect to each other, as a result of the sub-atmospheric pressure in the casing(s) and the simultaneous compression of the mixture by means of the pressure rollers. By not exerting a force in the direction of the conveyor belt by means of the pressure rollers during said second periods, the casing(s) and the belt can move with respect to each other, without undesirably large forces being exerted on the parts formed by the casing(s) and the conveyor belt which are moving with respect to each other, which forces might lead to excess wear and/or rupture of the parts in question.
It is noted that from FR-A-2,168,154 a device is known which is provided with a filter belt which moves over a trough. Near said trough a few pressure rollers are disposed above the filter belt, said rollers only being supported on the belt under the inflence of their own weight. It is

not possible hereby to release the pressure exerted on the material by the rollers, nor is it possible to control the pressure exerted by the rollers independently. Consequently such a construction will not be suitable for use in a device wherein the belt moves over casings in which a sub-atmospheric pressure can be generated.
US Patent No. 4101400 discloses a device having a filter belt supported by rollers. Above said filter belt there has been arranged a further belt which is passed over further rollers, said further rollers cannot be displaced independently of each other.
A similar device is known from US Patent No. 3,531,404. This publication does not relate to a device in which the extraction of liquid from a mixture is promoted by means of a vacuum either. Also with this known device the rollers occupy a fixed position with respect to the conveyor belt, by means of which the material to be de-watered is moved. Said publication does mention, however, that the rollers are mounted in such a manner that it is possible to adjust the pressure exerted by the rollers, but no means are provided for moving the rollers, once they are arranged in a certain position, to and fro between a position in whcih they exert an effective pressure on the mixture to be de-watered and a position, in which no substantial pressure is exerted on said mixture.
Further there is known from FR-A-2416043 a device haivng a filter belt which is continuously driven during operation of the device. The filter belt is vibrated by a vibrating device and downstream of said vibrating device there are arranged pressure rolls continuously pressing the mixture on the filter belt.
According to the present invention there is provided a device for removing liquid from a mixture of liquid and solid matter, said device being provided with an endless conveyor belt which is pervious to liquid, one or more casings over which a conveying portion of said conveyor belt moving the mixture during operation is led, means being provided for

intermittently effecting a relative movement between said casings and said conveyor belt and a relative standstill between the casings and the conveyor belt as well as means for generating a sub-atmospheric pressure in said casing(s) during the periods when the conveyor belt and the casing(s) do not move with respect to each other, characterized in that a plurality of pressure rollers extending transverse to the direction of movement are disposed above a conveying portion of the conveyor belt extending over a said casing(s), presser means being provided by which said pressure rollers are independently pressable down in the direction of said conveyor portion and removable in a direction away from said conveying portion and driving means are connected to supporting rollers below said casing(s) opposite the pressure rollers whereby the peripheral velocity of the parts of said supporting rollers making contact with the casing(s) is at least substantially equal to the velocity of displacement of the part of said conveyor belt supporting the mixture.
When using such a device it is possible, if required, to exert additinally and independently pressures on the mixture present on the conveyor belt, by means of the various rollers, during those period in which a vacuum is generated in the casing(s), as a result of which a very effective de-watering adapted to the material to be processed can be achieved.
The invention will be explained in more detail hereafter, with reference to a few possible embodiments of a device according to the invention diagrammatically illustrated in the accompanying drawLr«g,s.
Figure 1 is a diagrammatic side elevational view of a first embodiment of a device according to the invention.
Figure 2 is a larger-scale view of a part of the device shown in Figure 1.
Figure 3 is a cross-sectional view of Figure 2.
Figure 4 is a diagrammatic, larger-scale view of a part of the device shown in Figure 1, illustrating a modified embodiment.
Figure 5 is a diagrammatic side elevational view of a second embodiment of a device according to the invention.
Figure 6 is a larger-scale cross-sectional view of a part of Figure 5, wherein for easy reference certain parts have been left out.
Figure 7 is a side elevational view of a third possible embodi¬ment of a device according to the invention.
The device shown in Figure 1 comprises a endless conveyor belt 1 which is pervious to liquid, said conveyor belt being passed over guide rollers 2 and a drive pulley 3.
The upper part of the conveyor belt 1, on which the mixture of liquid and solid matter is present during operation, and which thus forms the mixture-moving conveying portion of the conveyor belt, is "ed over one or more casings 4 which are coupled together, said casings being connected, by means of pipes 5, to vessels 6 in which a sub-atmospheric pressure can be generated by means of a vacuum pump 7 connected to said vessels. Liquid collected in said vessels 6 can be discharged via the pipes 8. The casings 4 can be moved to and fro in the direction indicated by the arrow A by driving means (not shown).
The construction of such a device, as far as described above, is generally known per se.
According to the invention a plurality of rollers 9, three in the illustrated embodiment, are provided near the downstream end of the upper conveying portion of tne conveyo" belt 1. Said rollers 9 are resting on a part of a pressure belt 11 supported by guide rol lers 0 said part exten¬ding parallel tc tne upper part of the conveyor belt 1.
As is illustrated in more detail in Figures 2 and 3, each of tne
rollers 9 is freely rotatably supported by a shaft 12. The ends of each shaft 12 are coupled to setting cylinders 13, by means of which the shaft 12, and with it the roller 9 supported by the shaft 12 in question, can be moved in vertical direction.
Three supporting rollers 14 extending parallel to the rollers 9 are disposed under the casing(s) 4, near the pressure rollers 9. Each supporting roller 14 is mounted on a shaft 15. Each shaft 15 has a sprocket wheel 16 mounted on one of its ends. An endless driving chain 18 is passed over said sprocket wheels and over a sprocket wheel 17 coupled to the driving drum 3, as is diagrammatically indicated in Figure 2.
Near the supporting rollers 14 a reinforcing place 18 is provided between the supporting rollers and the bottom side of the casing(s) 4.
During operation the conveyor belt 1 wi11 generally be driven continuously by means of the driving drum 3, in such a manner that the upper part of said conveyor belt 1 is moved in the direction according to the arrow B. As already said before the casing(s) 4 are moved to and fro during operation by driving means (not shown). When the casings move in the same direction as the upper part of the conveyor belt 1 a sub-atmospheric pressure will be generated in at least some of the casing(s) 4, so as to suck liquid from the mixture of liquid and solid matter present on the belt 1. During the movement of the casing(s) 4, in a direction opposite the direction of movement of the conveyor belt, generally no vacuum will be maintained in the casing(s! 4, in order to prevent the conveyor belt from adhereing to the casings during the return movement.
Whilst the casings 4 are moved in the same direction as the upper part of the conveyor belt 1, the rollers 9 wi11 be pushed downwards by means of the setting cylinders 13, so as to exert pressure, via the pressure belt 11, on the material present on the conveyor belt 1, in order to squeeze moisture from said material. The compressive force exerted on the casing(s) 4 is thereoy transmitted, via the plate 18, to tne supporting rollers 14. Tne drive of said suoporting rollers by means of the chain 18 and the sprocket wheels 16 and 17 is thereby chosen such that the peripheral velocity of the parts of the supporting rollers 14 making contact witn the plate 18 is at least substantially equal to the rate of displacement of the conveyor belt 1 in the direction indicated by
the arrow B.
During the return movement of the casings the pressure rollers 9 will be moved upwards, so as to prevent the occurrence of undesirable
forces in the system.
Preferably the forces exerted on the pressure rollers 9 by means of the setting cylinders 13 can be independently adjusted for each pressure roller, so as to be able to squeeze out the material present on the conveyor belt 1 in the most optimal manner.
Of course modifications and/or additions to the above-described embodiment are possible within the spirit and scope of the invention.
Thus it is e.g. conceivable, as is also the case with similar known devices, to drag along the casings 4 in the direction according to the arrow B by means of the conveyor belt 1, by the forces which are generated as a result of the conveyor belt being sucked against the casing(s) 4. Since large forces are exerted by the pressure rollers, however, it is preferred to provide a positive drive for the casings 4.
Furthermore a casing 20 may be provided beside the pressure rollers 9, as is diagrammatically shown in Figure 4, via which pressur¬ized air or a suitable gas can be blown through the layer of mixture present on the conveyor belt 1, so as to blow off moisture present in said layer of mixture in this manner. The casing 20 may occupy a fixed position thereby, or be reciprocatingly movable by means of setting cylinders, in a similar manner as the pressure rollers 9.
Also it will be possible within the spirit and scope of the invention to provide the pressure rollers 9 and/or the casing 20 without using the pressure belt 11.
With the embodiment according to Figure 5 use is made of a number of casings 21 which are pivotal-y coupled together so as to form an endless chain, sa^d casings being passed over guide rollers 22, whereby at least one of said guide rollers is driven. Said device is furthermore provided witn an endless conveyor belt or filter belt 23 whose path, guided by guide rollers 24, is such that the upper part of said conveyor belt 23 is supported on the upper part of the endless chain formed by the casings 21. The bottoms of the casings 21 are provided with perforations, which move, in tne upper part of the chain formed by the casings 21, over casings 25 disposed under said upper part, in which casings a
sub-atmospheric pressure can be generated by means similar to those described with reference to the first embodiment.
Near the downstream end of the upper part of the conveyor belt 23 pressure rollers 9 and a pressure belt 11 are provided again, in a similar manner as explained with reference to the first embodiment. Near said pressure rollers 9 the casings 21 are supported by supporting rollers 26 provided under the casings 21 and on both sides of the casings 25, which supporting rollers 26 can again be rotated via a chain 27.
With this device the endless chain formed by the casings 21 and the conveyor belt 23 moves continuously in the direction according to the arrow C, whilst a sub-atmospheric pressure is being generated in the casings 25. By means of the rollers 9 a pressure may be exerted again, in a similar manner as described above, on the layer of mixture present on the upper part of the conveyor belt 23. Said pressure may be exerted continuously or intermittently and/or different for each roller, as required.
Figure 7 shows an embodiment wherein an endless conveyor belt 28 is moved over a number of stationary casings 29, in which a sub-atmos¬pheric pressure can be generated in a manner similar to the one described above. The belt 28 will thereby be driven in steps in the direction indicated by the arrow D.
In this embodiment the pressure rollers 9 and the pressure belt 11, if provided, are accommodated in a frame part which is reciproca-tingly movable, by means of a setting mechanism 30, in the direction according to the arrow E.
During the movement of the conveyor belt 28 in the direction according to the arrow D the rollers 9 wi11 be pressed down, in the manner described above, on the layer of mixture which is present on the conveyor belt 28 and which is simultaneously moved, by means of the setting mechanism 30, in the same direction as the upper part of the conveyor belt 28. During the standstill period of the intermittently moving belt 28 the pressure rollers 9 wi11 be moved upwards and the frame part supporting the pressure rollers will be returned to its initial position in a direction opposite the direction of movement of the upper part of the belt 28.




We claim:
1. A device for removing liquid from a mixture of liquid and solid
matter, provided with an endless conveyor belt (28) which is previous
to liquid and with one or more casings (29) over which a conveying
portion of the conveyor belt (28) moving the mixture during operation
is led, whereby means are provided for intermittently effecting a
relative movement between the casings (29) and the conveyor belt (28)
and a relative standstill between the casings (29) and the conveyor
belt (28), as well as means (5-7) for generating a sub-atmospheric
pressure in said casings (29) during the periods when the conveyor
belt (28) and the casing(s) (29) do not move with respect to each other,
characterized in that a plurality of pressure rollers (9) extending
transversely to the direction of movement are disposed above a
conveying portion of the conveyor belt extending over a casing (29)
having a fixed position, whilst means are provided by which said
pressure rollers (9) can be independently pressed down in the
direction of the conveying portion and be moved in a direction away
from the conveying portion.
2. Device for removing liquid from a mixture of liquid and solid matter
substantially as hereinbefore described with reference to and as
illustrated in the accompanying drawings.


Documents:

1674-del-1997-abstract.pdf

1674-del-1997-claims.pdf

1674-del-1997-correspondence-others.pdf

1674-del-1997-correspondence-po.pdf

1674-del-1997-description (complete).pdf

1674-del-1997-drawings.pdf

1674-del-1997-form-1.pdf

1674-del-1997-form-13.pdf

1674-del-1997-form-19.pdf

1674-del-1997-form-2.pdf

1674-del-1997-form-3.pdf

1674-del-1997-form-4.pdf

1674-del-1997-form-60.pdf

1674-del-1997-gpa.pdf

1674-del-1997-petition-137.pdf

1674-del-1997-petition-138.pdf


Patent Number 214859
Indian Patent Application Number 1674/DEL/1997
PG Journal Number 10/2008
Publication Date 07-Mar-2008
Grant Date 18-Feb-2008
Date of Filing 20-Jun-1997
Name of Patentee PANNEVIS B.V.
Applicant Address ELEKTRONWEG 24, 3542 AC UTRECHT, THE NETHERLANDS
Inventors:
# Inventor's Name Inventor's Address
1 ALPHONS ARNOLDUS JOHANNES ANTONIUS PRINSSEN VAN STRAELENLAAN 31,5224 GN'S-HERTOGENBOSCH, THE NETHERLANDS
PCT International Classification Number B01D 33/04
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA