FR2553976A1 - Continuous filter press for grapes etc. - has convergent filter bands with hopper spreading grapes and pre-pressing on upper band - Google Patents

Abstract

A filter press of the continuous type in which food prods., partic. winemaking grapes, are pressed between a pair of superimposed conveyor bands converging in the direction in which their adjacent faces are both moving. A feed hopper delivers prod. on to the upstream end of the lower band which is perforated to allow expressed juice to pass through. The angle of convergence of the bands is adjustable. The upper band is guided to follow a horizontal path and the feed hopper delivers on to the upper surface of this band. The hopper is equipped to spread the prod. over the full width of the band and also to subject the spread prod. to a preliminary pressing operation before transferring it to the gap between the two bands. USE/ADVANTAGE - A filter press for extn. of juice from fruit or vegetables, esp. from grapes. Spreading and pre-pressing greatly increase extn. yield. Band washing avoids stoppages to clear blocked mesh in the bands.

Description

 The invention relates to improvements in continuous filter presses, with converging bands, intended for pressing food products in general and grapes in particular.

It has long been known to use continuous filter presses which comprise: a pair of overlapping converging bands, moving in the same direction and of which at least the lower band is provided with meshes allowing the filtering of the liquid part of the pressed product, a loading hopper for supplying product to be treated to the lower strip, and means for varying the angle of convergence of said strips according to the type of pressing desired and the type of product being treated. Presses of this kind are described, for example in Patents FR-An "583.406,
FR-A-2.096.883, FR-A-2.272.828, US-A- 3.106.152, US -A- 3.330.

206 and US-A-3,796,149.

 The output of these conventional presses does not reach optimal values, because the product to be treated is supplied from the loading hopper directly to the lower belt, this supply taking place practically according to a fixed jet; thus the product is collected on the lower strip in a continuous line of substantially horizontal direction: practically, there is no distribution of the product along the width of the strip, which results in an irregular pressing action when the product is fed to the wedge-shaped region delimited by the two converging bands.

 Another drawback, which reduces the yield of conventional filter presses, is rapid in clogging of the filter meshes with solid residues, requiring the machine to be stopped to clean it.

 The object of the present invention is to provide improvements to continuous filter presses with converging bands, with a view to eliminating the aforementioned drawbacks and thus bringing the efficiency of said devices to values close to 100%.

 The continuous filter press with converging bands, according to the invention, which is of the type comprising a pair of bands placed one above the other and moving in the same direction to delimit a region in the form of a corner and at least the lower band of which is provided with filtering meshes, a loading hopper for supplying the product to be treated with the lower band, and means for varying the angle of convergence of said bands, is characterized in that the upper strip of the pair of strips is guided along a substantially horizontal path, and the loading hopper surmounts said substantially horizontal path, this hopper being equipped with: means capable of distributing the product under treatment over the entire width of the upper strip, means for preliminary pressing of said product, means for collecting the liquid deriving from this pretreatment.

 According to another characteristic of the invention, the filter press is equipped with means associated with each of the aforementioned bands, which make it possible to carry out the washing thereof without it being necessary to stop the operation of the press.

 These characteristics and others will emerge clearly from the following description.

To fix the subject of the invention illustrated in a nonlimiting manner in the figures of the drawings where:
Figure 1 is a schematic side view of the press as a whole.

 Figure 2 is a perspective view illustrating, on a larger scale, the loading hopper, the pretreatment device and the washing device.

 Referring now to the above figures, it can be seen that the press according to the invention comprises, in a conventional manner, a first lower strip (1) driven in the direction of arrow F, for example, by a motorized roller (2 ) of horizontal axis, and returned by rollers (3), (3 '), the roller (3') being equipped with pneumatic bearings (4) ensuring the tension adjustment of the strip (1). Above the strip (1) is disposed a second upper strip (5) driven in the direction of the arrow F, for example by a motorized roller (6) which can be actuated by the same motor group (M) controlling the roller (2) .The belt (5) is returned by rollers (7), (7 '), the roller (7') being equipped with pneumatic pads (4) allowing to adjust the tension of the belt (5).

 The superimposed bands (1) and (5) delimit between them a region forming a wedge (8) whose angle of convergence can vary by usual means, not illustrated; the bands pass, overlapping, on a first roller (9) of a row of rollers (9 ') of final pressing, to separate again near the motorized rollers (2) and (6).

 The upper strand of the strip (5) is guided along a substantially horizontal path and this path is surmounted by a loading hopper - generally designated by the reference (10) - inside which the product to be treated is brought by a conventional duct (11). This conduit (11) is connected by a connector (12) to a distributor member (13) which a suitable motor, not shown, oscillates in the direction of the arrows H in a vertical plane and transverse to the strip (5).

The hopper (lo) is extended by two side walls forming edges (14) which enclose the strip (5) near the return roller (7) placed at the start of the region forming the corner (8).

 A bar of square section, mounted between the edges (14), is maintained substantially in contact with the strip (5), this bar being controlled in rotation in the direction of arrow G by a suitable motor (16). Alternatively, the bar has roughness or edges over its entire length.

A collecting tank (17) provided with an orifice (17 ') is placed below the hopper (10), under the substantially horizontal strand of the strip (5). Similar collecting tanks (18), (19) and (20), each provided with a drainage orifice (18 '), (19') and (20 ') respectively, are placed below the region forming corner (8) and rolls (9) and (9 ') of final pressing. Another collecting tank (21) is placed below the tanks (18), (19), (20) and its orifice (21 ') opens into a screening drum (22) provided with fittings (23) for distribution, differentiated in quality, of the liquid from pressing.

 The bands (1) and (5) have a density of filtering meshes which is a function of the type of product to be treated and each band is equipped with a washing device generally designated by the reference (24). These washing devices (FIG. 2) each consist of a box-shaped body (25) provided with a slot (26) for the passage of the associated strip, this body receiving a tube (27) carrying nozzles or nozzles. -es (28) directed to the underlying strip and provided with a connector (29) connecting the tube to a source of clean water. The tube (27) projects beyond the body (25) by an extension (30), the end of which can be provided with a device (not illustrated) of any suitable type allowing the cleaning of the nozzles or nozzles (28). connection (31) is provided below the body (25) and allows the evacuation of the washing water.

 As shown in Figure 1, the devices (24) are stored in suitable locations, for example on the lower strand of the strip (1) and upstream of the loading hopper (10) surmounting the strip (5). During an operation, the product to be treated - grapes, for example - is brought to the distributor (13) through the conduit (11) to be distributed by the latter in a uniform manner over the entire width of the strip (5). As the strip (5) moves, the product is subjected to a combined treatment of stirring and preliminary pressing under the effect of the square section bar (15) driven in rotation. The liquid part thus expressed is collected in the tank (17) placed below. The liquid flowing from this tank (17) is conveyed via a conduit (not shown) connected to the flow orifice (17 '), to the tank (21) and from here, through the sieve tube ( 22) which separates any solid residues, towards a final collecting tank (not shown). Following this pretreatment, the product pours onto the initial part (arrows S) of the lower strip (1) where the product is conveyed to the wedge region (8) to be subjected to pressing proper and pass over the rolls (9) and (9 ') of final pressing. The liquid part collected successively in the tanks (18), (19) and (20) falls back through the orifices (18 '), (19') and (20 ') in the underlying tank (21), then in the screen drum (22) .If you want to separate the liquid parts coming from the pretreatment of the liquids expressed later during the actual pressing and the final pressing, it is enough to connect the different flow orifices (17 '), (18' ), (19 ') and (20'), by appropriate conduits (not shown) to individual final collection bins. By means of the washing devices (24), the bands (1) and (5) can be cleaned without stopping the work of the press by admitting water under pressure into the tubes (29) associated with the devices (24); the pressurized water expelled from the nozzles (28) sweeps the moving moving strips (1) and (5). The solid residues are removed from the press in a conventional manner at the point where the strips (1) and (5) separate from one another.

 From the above, it can be appreciated that the improved filter press according to the present invention makes it possible to obtain a yield very close to 100%, and this thanks to the uniform distribution of the product to be treated over the entire width of the upper strip, to the pretreatment of the product with collection of the liquid thus expressed, and of the fact that the moving bands are cleaned in a constant manner, which prevents any blockage of the filtering meshes.

Claims (1)

CLAIMS -1- Continuous filter press with converging bands intended for the pressing of food products in general and grapes in particular, of the type comprising a pair of superimposed bands driven in the same direction to delimit a wedge-shaped region, at least the lower strip being provided with filtering meshes, a loading hopper intended to supply the product to be treated with said lower strip, and means for varying the angle of convergence of said strips, characterized in that the upper strip (5 ) of the pair of bands is guided along a substantially horizontal path, and in that the hopper (10) surmounts the substantially horizontal path and comprises means (11 - 12 - 13) making it possible to distribute the product under treatment over the entire width of the upper strip, and means (15, 16,  17) to subject the product to a pressing pretreatment and to collect the liquid expressed during this pretreatment. -2- Filter press according to claim 1, characterized in that the hopper (10) comprises a distributor member (13) controlled in oscillation in a vertical plane and transverse to the upper strip, said member being supplied with product to be treated by the way of a conduit (11). -3- Filter press according to claim 2, characterized in that a pair of side walls forming edges (14) extend from the loading hopper (10) to enclose said strip (5) at least along its substantially horizontal path, at least one pretreatment member (15) being arranged transversely between said edges so as to be substantially in contact with the strip or immediately near it. -4- Filter press according to claim 3, characterized in that the pretreatment member (14) is a bar controlled in rotation about its own axis, said bar having aces provided on the entire length of the bar. -5- Filter press according to claim 4, characterized in that said bar is, advantageously, of square section, or has edges. -6- Filter press according to claim 1, characterized in that it comprises means (24) placed along the path of each strip which allow to perform the washing of the associated strip during the movement thereof. -7- Filter press according to claim 6, characterized in that said washing means (24) consist of a hollow body (25) through which the associated strip can pass, this hollow body supporting a means (27) provided orifices forming nozzles (28) which project water onto said associated band driven in movement.