Separating device

Abstract: The invention relates to a device for separating liquids and solids. An endless filter belt is used, beneath which a suction box is placed which can generate underpressure relative to the ambient pressure. The suction box is bounded on at least one of the sides by a stationary underpressure box, wherein the suction box is provided with connecting means co-acting with the underpressure box. This enables embodying of the connection between the suction box and this underpressure box without for example rubber connecting hoses. This is important because rubber material cannot for instance withstand high temperatures.

Description: The invention relates to a device for separating liquids and solids from a mixture, means for supporting the filter belt, means for supplying mixture to the filter belt, a stationary underpressure device for generating a lower pressure, which underpressure device is arranged to extend laterally along the separating device. Such a device is known from document NL-A-8303016. Document NL-A-7210541 discloses a device for separating liquids and solids from a mixture, with an endless filter belt, means for supplying mixture to the filter belt, at least one suction box supporting the filter belt, located under the filter belt and moving along with the filter belt, which suction box is connected to an underpressure device for generating a lower pressure relative to the ambient pressure, and control means for alternately generating this lower pressure and ambient pressure in the suction box, and discharge means connected to the suction box. The suction box is connected to the underpressure device by means of hose connections. This causes various drawbacks. Due to the possible cross-sectional size of the hose the amount of air and liquid which can be sucked through is limited. Because they are bent the hoses cause an undesired force transversely of the direction of movement of the filter. This force is relatively great and varies during the movement of the suction box. In addition, as a result of the material of the hose, rubber, it is not possible to apply higher temperatures. A final drawback is that the reciprocating mass is comparatively large as a result of the weight of hose and coupling means. The invention obviates these drawbacks. This is achieved according to the invention in that the suction box is bounded on at least one of the sides by a stationary underpressure box and the suction box is provided with connecting means co-acting with the underpressure box. By placing a stationary underpressure box on the side of the suction box it is possible to embody the connection between the suction box and this underpressure box without rubber hoses. According to a preferred embodiment it is for instance possible to opt for a slot-like opening in the underpressure box, wherein the suction box is movable with a connecting piece in lengthwise direction through this slot-like opening. The mass displaced during the reciprocating movement is thus limited to that of the suction box itself. There are in addition no limitations imposed by the material of the connecting means for the temperature of the mixture for separating. Finally, it is possible to choose the cross-sectional size of the connecting piece of the suction box such that there is no limitation in respect of the amount of air and liquid which can be drawn through, so that the capacity of the device can be chosen as required. In order to close the slot-like opening on either side of the moving connecting piece of the suction box, the suction box and the underpressure box are equipped with mutually co-acting sealing means. The invention is further elucidated with reference to the drawings. In the figures: Fig. 1 shows a perspective view of the first embodiment of the invention, Fig. 2 shows a sectional view of a part of the embodiment of fig. 1, and Fig. 3 is a perspective view of an alternative embodiment. The separating device according to the invention comprises an endless filter belt which is trained round drive rollers 2, 3. From a feed hopper 4 the mixture for separating is supplied to the upper part of filter belt 1. Arranged under the filter belt is a suction box 5 which on the top side takes the form of a grid with a chosen mesh width 6. The suction box 5 is connected by means of valves 7, 8 to means (not drawn) for generating vacuum. At the end of the upper part of filter belt 1 the product is discharged via means 9 intended for that purpose. Connected to the suction box 5 is a cylinder-piston construction 10 which provides suction box 5 with a resetting force. In the movement according to arrow 11 and the return movement the suction box 5 is guided over roller tracks 12. The guiding can also take place over slide tracks (not shown). According to the invention the suction box 5 is bounded on at least one side by a stationary underpressure box 13. The suction box 5 protrudes with a connecting piece 14 into the slot-like opening of the underpressure box 13. Sealing means 16, 17 are placed between the slot-like opening 15 and connecting piece 14. The underside of suction box 5 is formed by a bottom plate placed in inclining position. The placing of this bottom plate out of alignment increases the hydraulic capacity of suction box 5. The separating device according to fig. 1 and 2 operates as follows. By generating underpressure in suction box 5 a coupling is created between the moving filter belt 1 and the suction box. Suction box 5 is carried along by the belt and the product for separating is sucked in by the suction box 5 and discharged via the underpressure box 13. At the end of the work stroke the underpressure is released, whereby suction box 5 is detached from the filter belt 1. The piston-cylinder construction 10 produces a resetting force whereby suction box 5 moves back to the beginning of the work stroke. The above described operation is then repeated. According to an alternative embodiment as in fig. 3, underpressure boxes 20, 21 are placed on either side of filter belt 1. In this embodiment the filter belt 22, 23 lies at the sides on the respective sloping parts 24, 25 of the respective underpressure boxes 21, 20. Sealing means can be situated at the position where suction box 5 connects onto boxes 20, 21. The operation is the same as that of the embodiment of fig. 1.

Claims: Device for separating liquids and solids from a mixture, said device comprising an endless filter belt (1), means (3) for supporting the filter belt, means (4) for supplying mixture to the endless filter belt, a stationary underpressure device (13) for generating a lower pressure, which underpressure device is arranged to extend laterally along the separating device, characterized in that at least one suction box (5) is located underneath the filter belt, which suction box (5) supports the filter belt and is arranged to move along with the filter belt, wherein the suction box (5) is connected to the stationary underpressure device (13), which stationary underpressure device is bounded lengthwise on at least one lateral side of the suction box to enclose said lateral side of the suction box and that the suction box is provided with connecting means (14) extending along the lateral side thereof to coact with an opening (15) in the stationary underpressure device. Device as claimed in claim 1, characterized in that the underpressure box (13), has a slot-like opening (15) and the suction box is movable with a connecting piece (14) in lengthwise direction through the opening. Device as claimed in claims 1 and 2, characterized in that the suction box (5) and underpressure box (13) have mutually co-acting sealing means (16),(17). Device according to any of the previous claims further comprising automatic resetting means for resetting the suction box under the filter belt. Device according to claim 4 wherein the resetting means comprise a hydraulic cylinder piston(10) arrangement. Device according to any of the previous claims wherein the suction box is guidable over roller (12) and or slide tracks associated with the device. Device according to any of the previous claims wherein the suction box (5) has a top side equipped with a grid (6) having a predetermined mesh width. Device according to any of the previous claims wherein the underpressure box (13) is connected to underpressure inducing means. Device according to claim 8 wherein one or more valves are arranged between the underpressure box and the underpressure inducing means for regulating the underpressure. Device according to any of the previous claims wherein an uppersurface of the stationary underpressure box lies in the same imaginary horizontal plane as the endless filter belt.

Inventors: PRINSSEN ALPHONS ARNOLDUS J A, THISSEN KAREL ANTOON, PRINSSEN, ALPHONS ARNOLDUS J.A., THISSEN, KAREL ANTOON
Applicants: PANNEVIS BV, PANNEVIS B.V.
Application year: 1995
Main classification: B01D33
IPC codes: B01D33, B01D29