US2365658A

US2365658A - Apparatus for the removal of water, liquors, or other liquids from soaked masses of fibrous materials

Info

Publication number: US2365658A
Application number: US383415A
Authority: US
Inventors: Schumacher Fritz
Original assignee: American Voith Contact Co
Current assignee: American Voith Contact Co
Priority date: 1939-06-20
Filing date: 1941-03-14
Publication date: 1944-12-19
Anticipated expiration: 1961-12-19

Description

Dec; 19, 1944. F. SCHUMACHER 2,365,653 APPARATUS FOR THE REMOVAL OF WATER, LIQUQRS OR OTHER LIQUIDS FROM SOAKED MASSES OF FIBROUS MATERIALS I I Filed March 14, 194], 2. Sheets-Sheet l 3 F J, INVE%TOR. 1 I! Z lZi/Zlll 6V. @25 BY C 7 7 Dec. 19, 1944. F. SCHUMACHER 2,365,658 APPARATUS F THE REMOVAL OF WATE LIQUORS OTHER LIQUIDS M SOAKED MASSES OF F ROUS MAT ALS Filed March 14, 1941 2 Sheets-Sheet 2 IN VENTOR.

M ATTORNEY Patente Dec. 19, 1944 APPARATUS FOR THE .LIQUORS, R OT REMOVAL OF WATER, HER LIQUIDS FROM SOAKED MASSES 0F FIBROUS MATERIALS Fritz Schumaeher, Oberlenningen, Wurttemberg, Germany, assignor to American Voith Contact Co. Inc., New York, N. Y.,

York

a corporation of New Application March 14, 1941, Serial No. 383,415

In Germany June 20, 1939 v 1 Claim.. (Cl. 100-37) This invention relates to anew and useful improvement in apparatus for the removal of water,

I liquors or other liquids from soaked masses of fibrous materials, such as cellulose, mechanical wood pulp, or the like, to thicken the latter,and has for its object to provide a device of this character which is continuous in operation with high liquid-removal efiiciency and without damage to the fibers of the material being treated.

The invention consists in introducing the fibrous material between the periphery of a rotating perforated drum and an endless belt which partly surrounds the latter; and gradually increasing the pressure of the belt against the periphery of the drum toward the end of the belt run, whereby the liquid is more moved from the fibrous material.

The invention also resides in a cylindrical drum provided on its outer periphery with a plurality of annular grooves, the bottom of which communicate with the interior of the drum through the medium of transverse openings.

With the above and other objects in View which will appear as the description proceeds, the invention resides in the novel feature hereinafter set forth, illustrated in the accompanying drawings and more particularly pointed out in the appended claim.

Referring to the drawings in which numbers of like character indicate similar parts throughout the several views, I I

Fig. 1 is a diagrammatic end view of the apparatus with the drum shown in cross-section, and illustrating the arrangement of the guide and compression rollers for the endless belt, the washing device, and a drive for the drum.

Fig. 2 is a view similar to Fig. 1 but showing a drive connection for the endless belt instead of (a drive for the drum shown in Fig. 1.

Fig. 3 is a fragmentary detailed view of the Fig. 4 is an enlarged horizontal sectional view of a portion of the drum shown in Fig. 3.

Fig. 5 is a diagrammatic view wherein the endless belt forms a feeding conveyor for the material to the cylindrical drum, said drum being shownin section.

Fig. 6 is a view similar to Fig. 5 having preliminary water-removal means in the conveyor completely rerun of the endless belt.

Fig. 7 is a diagrammatic view wherein the endless belt forms a delivery conveyor for the treated material leaving the periphery of the drum, and

E18. 8 is a view similar to Fig. 7 but including supplemental water removing means in the de- 'livery conveyor run of the endless belt.

In the drawings, a hollow rotatable perforated cylindrical member or drum I, having end shaft portions la (Fig. 3) is rotatably supported in suitable bearings, not shown. An endless member or belt 2, partially surrounds the drum I and is guided over rollers 3, 4,-5, 6 and 1, of which rollers 5 and I are preferably designed as tension rollers for taking up any slack in the belt 2. Along the inner run of the belt 2, compression rollers 8, 9, III, II, and I2 are provided, whose compression may be adjusted whereby the belt 2 is .forced against the drum I with a gradually increasing pressure from the compression roller 8 to the compression roller I2, as clearly shown in Fig. 1. It will beseen in the drawings that the space between the belt 2 and the drum I, is larger at the entrance roller 3 than at the discharge roller 1, the entrance end having more water than the discharge end, the compression rollers bein correspondingly adjusted.

- By this arrangement of guide rollers and compression rollers, the belt 2 encircles the drum I for approximately of its circumference.

Drum I is rotated by any suitable means such as belts, gear wheels, etc., that?" shown in the drawings being a worm shaft 26 driven from a suitable source of power, not shown, said shaft meshing with a complementary gear 26a on the shaft lajEof I to drive the latter in the directionof. the arrow shown in Fig. 1. Due to the frictional engagement of the belt 2 with the drum I, rotation of the drum by the driving means above described moves the endless belt 2 in the same direction so thatthe material to be treated entering the inner run of the belt 2 adjacent the guide roller 3 is gradually compressed to remove the water therefrom.

Any foreign matter or impurities collecting on c the belt 2 can be removed by a scraping and washing device cooperating with the outer run of the belt 2 and comprising a number of pipes I3 for spraying jets of water against the belt, and brush rollers II for loosening any encrustations so that the same can be washed by'the spraying jets of water. The cleansing water runs off the belt 2 and is collected in the trough I5 from whence it can be conducted to any suitable point.

The cylindrical drum as shown in Figs. 3 and 4 is provided about its periphery with a series of circumferential grooves 33 in the bottom of each of which are a plurality of apertures 34 communicating with the interior of the drum I.

Having described the construction of one embodiment of my invention, its operation is as follows:

The soaked fibrous material enters the inner run of the endless belt 2 adjacent the guide roller 3 where the belt is spaced a predetermined distance from the periphery of the drum to form an entrance.

As the fibrous material travels about the periphery of thedrum I, the inner run of the belt 2 compresses said material into a layer to expel the water therefrom into the apertures 34 and into the interior of the drum I from whence the water flows through outlet openings in the end faces of the drum. During this operation, on the first quadrant of the drum I, the layer of material moves downwardly and water will flow in abundant quantity into the interior of the drum through the above-mentioned apertures 34. The second quadrant of the drum circumference, or the bottom thereof will be covered in part on the inside by the water removed from the material during the first quadrant; however, the gradually increasing pressure of the compression rollers 8 and I compresses the layer of the fibrous materials sufiiciently to prevent such water from becoming reabsorbed by the layer. On the third or last operation quadrant of the drum the layer of material moves in an ascending direction and is further compressed between compression rollers II and I2 pressing the belt 2 against the periphery of the drum l. After the layer of the material passes compression roller I2, the pressure thereon is reduced to that pressure exerted by the tension on the belt 2; consequently this drop in pressure allows the layer of material to expand prior to being removed at the upper run of the belt adjacent the roller 1. During this upward travel, due to the annular grooves 33 on the drum I, the layer of fibrous material does not come into contact with the apertures 34 so that should there be any water in said apertures due to adhesion, it cannot come in contact with the layer of material to be reabsorbed thereby during expansion of said layer which occurs between compression roller I2 and roller 1. Furthermore, the grooves 33 in the upward travel of the drum I form downwardly directed channels betwen the individual apertures 34, in which channels the water pressed out of the layer flows downwardly and finally is driven into the interior of the drum I through apertures 34. It will thus be seen that at the point of removal of the treated layer, the annular grooves 33 are substantially free from water so that no water can return into said layer.

While in the foregoing form of the invention the drum 1 has been the member to be driven from a suitable source of power, movement of the endless belt 2 having been dependent upon the frictional engagement of the belt with the drum, it may be desirable and advantageous to connect the driving means to the belt 2 instead of to the drum as shown in Fig, 1. Such an arrangement is shown in Fig. 2, where the tension roller l of Fig. 1 at the discharge end of the belt run is replaced by a driving roller 21 preferably of larger diameter than the guide and

tension rollers

3, 4, 5, and 6, to provide a larger traction surface for the belt. Roller 21 may be driven from any suitable source and by any suitable belt or gearing arrangement, such for example as a motor M driving belt 29 which runs over the shaft 28 of the driving roller 21. If desired, the driving roller 21 may be rotated by a worm shaft arrangement similar to that shown in Fig. 1 for the drum I. As in the form heretofore described in connection with Fig. 1, compression rollers 8, 3, III, II and I2 are provided for forcing the inner run of the belt 2 -against the periphery of the drum I with a gradually increasing pressure.

With this arrangement, the endless belt 2 is positively driven from the discharge end of the run about the periphery of the drum I and is tensioned in a uniform manner between the

rollers

3 and 21, thereby eliminating the possibility of folds forming in the belt 2 which may develop when the drum is the member being driven due to the uneven compression about the drum and the consequent uneven traction tension.

An arrangement of guide and tension rollers for the endless belt whereby a portion of the belt may be used as a conveying means for the material to be treated, is shown in Fig. 5. In this arrangement, the outer run of the belt 2a extends from

rollers

6a, 5a, and 4a, and instead of running directly over the roller 3a adjacent the periphery of the drum Ia for the beginning of the inner run of the belt, it is led to a roller I6 located a predetermined distance away from the periphery of the drum Ia. From roller I6 the belt is conducted over roller 3a so that there is formed between rollers I6 and 3a a horizontally extending run I8 in the nature of a supply conveyor.

To remove some of the water from the material prior to being compressed between the drum and the inner run of the endless belt, pairs of rollers I9 and 20 as shown in Fig. 6, have the conveyor run I8 of the belt pass between them.

To form a horizontal conveyor run 22 for the treated layer of material discharged from the periphery of the drum lb, the endless belt 2b is guided over rollers 3b, 4b, 5b, 6b and lb, and adjacent the discharge end of the inner run about the drum II), the belt is led away from the roller lb to a roller 2| disposed in substantially the same horizontal plane as roller lb and located a predetermined distance away therefrom as shown in Figure 7. From roller 2 I, the outer run of the belt 2b is guided over rollers 6b, 5b, 4b and 3b from which last-named roller it begins its inner run in engagement, with the periphery of the drum I b which extends to the roller lb.

To further remove water from the layer of material after being treated on the drum Ib,

rollers

23, 24, and 25 as shown in Fig. 8, have the conveyor run pass between them, so that the material conveyed by said conveyor run 22 is further compressed between the

rollers

23, 24 and 25.

The relation of the belt to the drum as shown in the drawings of Figures 5, 6, 7 and 8 are diagrammatic, and in practice of course show the general relationship as shown in Figures 1 and 2.

A device constructed in accordance with the present invention, is especially advantageous in respect to removing continuously water from fibrous materials which possess fairly great initial thickness, such for example, digestor materials and the like. pressure to which the layer of material is subjected may be varied to suit different conditions of operation, and the elastic pressure of the belt does not injure the fibers. Th parts are accessible, the pressure of the belt can be maintained constant. In the suction-cell or pressure filters heretofore used for th removal of water from fibrous materials and the like, the only materials which could be treated had at most a density of 1.5%.

Furthermore, the water-removal On the other hand, with the present inaccepts vention', materials having a density of as high as 12% admit of being freed from water without difficulty, and even up to dry contents of 40% and over. The apparatus is also adaptable to the pressing out of acid, caustic solutions and the like and is particularly suited for the removal of water from paper pulps which have to be washed repeatedly, that where water has to be removed again and again after repeated washings with liquid. The pressure of the rollers increasing towards the material escape end makes it possible to overcome the capillary forces, which increase as the water has been removed, and which forces hold the water fast between the fibers, and bring about an extensive removal of the water. The grooves in the cylinder assist in a more extensive freeing of the material from the water. These grooves become important since the water forcing operation corresponds only to a travel of about of the circumference of the cylinder. In the groove construction in accordance with the invention, the layer of fibers does not come directly in contact with th upper edges of the individual boreholes; accordingly this suction effect does not occur at the abating of the pressing pressure. Besides that, however, these grooves constitute downwardly directed channels between the individual holes, in which channels the water that has been pressed out of the layer of fibers can collect and, contrary to the slow upward movement of this part of the cylinder, can fiow off downward and emerge into the interior of the cylinder from the holes that are situated lower down. Thus it comes to pass that at the point of removal of the layer of fibers the grooves in the immediate vicinity thereof are practically free from water and that therefore a return of the already pressed-out water into the layer can no longer take place.

The removal of water may be effected in this by means of belts, gear wheels, worm drive, or the a like and carries along by friction the endless belt which partially surrounds it. Since this arrangement, however, makes the endless belt dependent upon the adhesion to the cylinder, and since the belt, in traversing the interval between the cylinder and the guide rollers, tensing rollers, and adpression rollers, may show a tendency to the forming of folds in consequence of unequally acti'ng slippage, there is provided the further arrangement of driving the endless belt or/and by means of a guide roller which is fashioned as a driving roller and which advantageously is situated as close as possible to the discharge of the material. Thereby the endless belt, in its partial surrounding of the sieve drum from the entrance of the material to its escape, is made into a uniformly drawn strip which distributes the traction tension uniformly during the water-removal process and obviatescongestions of the fibrous material as a result of slackening of the band, by which means a uniform removal of water is attained. This arrangement has a favorable effect,

above all, also with respect to the adpression rollers. Instead of and together with perforating the drum, the belt might be perforated.

While the foregoing invention has been described in connection with the removal of water from fibrous materials, it is to be borne in mind that the invention is by no means intended to be limited to this particular application, as the device will operate with equal efficiency to remove acids, caustic solutions, liquors, or any other liquids from fibrous materials. In using the device for removing water, th endless belt is preferably constructed of material which is water repellent, such as rubber and the like, but it will be understood that for treating fibrous materials containing acids or other strong liquids, the endless belt should be constructed of materials which will resist the deleterious effects of such acids and strong liquors.

From the foregoing it is believed that the construction and advantages of the present invention may be readily understood by those skilled in the art without further description, it being borne in mind that numerous changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claim.

What is claimed and desired to be secured by Letters Patent is:

In an apparatus for treating fibrous liquid material to remove liquid therefrom, the combination of a hollow rotatable cylindrical member with an axis horizontally disposed, having a series of annular grooves extending circumferentially about the periphery of said member and having a series of apertures in the bottom of said grooves opening in communication with the interior of said cylindrical member, rollers, one at each side of the cylinder and having their axes above the axis of th cylinder, an endless impervious belt member passing over said rollers and having an inner run portion partially surrounding the peripheral portion of said cylindrical member, said surrounding portlon having its discharge part in contact with the cylindrical member, the remaining part spaced therefrom with its entrance part spaced th greatest distance from said cylindrical member the space between the cylindrical memher. and the belt member at the entrance and discharge ends being above the axis of said cylindrical member forming a hydrostatic head to enable pressure and gravity to act onthe intervening fluid against said member, means for driving one of said members to move the other by frictional engagement between the contacting parts of said members, and a plurality of compression rollers acting on the surrounding belt portion for forcing the material between the members into