US3230138A - Pulp dewatering apparatus - Google Patents

Description

Jan. 18, 1966 A. c. BERGES PULP BEWATERING APPARATUS 7 Sheets-Sheet 1 Filed May 21, 1963 Jan. 18, 1966 A. c. BERGES PULP DEWATERING APPARATUS 7 Sheets-Sheet 2 Filed May 21, 1963 w mo Jan. 18, 1966 A. c. BERGES 3,

PULP DEWATERING APPARATUS Filed May 21, 1963 '7 Sheets-Sheet 3 5/ 62 6/ 22 6/ g {4 x A 1 g\ g LY. 52 45 l V t l i 45 1a Iv ue'moa Jan. 18, 1966 A. c. BERGES 3,230,138

PULP DEWATERING APPARATUS Filed May 21, 1963 7 Sheets-Sheet 4.

in vewm E i! wm Jan. 18, 1966 A. c. BERGES PULP DEWATERING APPARATUS '7 Sheets-Sheet 5 Filed May 21, 1963 Jan. 18, 1966 A. c. BERGES PULP DEWATERING APPARATUS 7 Sheets-Sheet '7 Filed May 21, 1963 K L Q United States Patent 3,230,138 PULP DEWATERING APPARATUS Andre Charles Berges, Lorp par St.-Lizier, Ariege, France Filed May 21, I963, Ser. No. 282,669 Claims priority, application France, .Iune 6, 1962, 899,926 7 Claims. (Cl. 162-307) This invention relates to pulp processing apparatus of the type used to remove part of the liquid content in :pulps of fibre and similar wet divided materials, and is especially though not exclusively directed to paper making apparatus.

In the manufacture of paper and similar fibre pulp products, a wet pulp of comparatively high water content is delivered on to one end of an endless wire cloth which is continuously advanced over an underlying flat surface, which is provided with spaced slots or apertures through which suction is applied to the under surface of the Wire cloth so as to draw out part of the liquid from the pulp as it progresses towards the delivery end of the machine. In Fourdrinier machines used in the paper industry and embodying the above operating principle, a so-called wet press is frequently mounted beyond the delivery end of the wire cloth, said press usually including an endless movable felt adapted to receive the partly dried pulp from the wire cloth, and a pair of press rolls or cylinders engaging the upper and lower surfaces of said felt to wring further liquid out of the pulp, and simultaneously flatten the pulp fibres. Sometimes suction is also applied at the wet press to further these operations.

Objects of this invention are, broadly, to provide a number of improvements in pulp processing apparatus of the kind just outlined. Specific objects are to provide improved drying means, involving the joint actions of compression and suction, whereby the ultimate dryness of the pulp issuing from the wire cloth can be brought to a point substantially higher than was heretofore generally possible; to provide rolls in the suction chambers of such apparatus for engagement with the under surface of the wire cloth, and improved supporting means for such rolls whereby their pressure engagement with the wire can be more effectively controlled; to provide improved pulp drying apparatus operable to impart a higher degree of dryness to pulp fed thereto without increasing the general dimensions of the apparatus; simultaneously to facilitate the effective recovery of the valuable or harmful liquid constituents of the pulp to permit recovery or destruction, respectively, of such constituents; to provide in such apparatus combined suction and compression drying means as single separate units, readily insertable and with drawable into and from the frame of the apparatus from a side thereof; to provide such drying means in which the degree of pressure applied to the pulp will be more closely and easily controllable; to provide such drying means including drier rolls that can be made to extend the full width of the wire cloth without having to be enlarged or made convex in their mid-regions; to provide apparatus of the type specified above having improved provision for easy removal and replacement of the wire cloth. Other objects relate to the provision of improved wet presses, especially wet suction presses, for use with pulp drying apparatus of the general class referred to.

Exemplary embodiments of the invention will now be described in detail for purposes of illustration but not of limitation and with reference to the accompanying drawings, wherein:

FIGURE 1 is a side elevational view of a Fourdrinier machine embodying important teachings of the invention.

3,230,138 Patented Jan. 18, 1966 ice FIGURE 2 is a horizontal section on line IIII of FIGURE 1.

FIGURE 3 is a transverse section on line III-III of FIGURE 1.

FIGURE 4 is an end view of the machine on the line of view indicated by the arrow F in FIGURE 1.

FIGURE 5 is a vertical section on line V-V of FIGURE 2, but on an enlarged scale.

FIGURE 6 is a transverse section on line VI-VI of FIGURE 5.

FIGURE 7 is a detailed view in vertical section of one of the suction boxes, on a further enlarged scale.

FIGURE 8 is a horizontal section on the line VIIIVII of FIGURE 7.

FIGURE 9 is a further horizontal sectional view, on the line IXIX of FIGURE 7.

FIGURE 10 is a fragmentary view similar to FIG- URE 7 but relating to a modification in detail.

FIGURE 11 is a view illustrating the delivery end of a Fourdrinier machine which may be similar to the one generally shown in FIGURE 1 and following, but including a wet press according to a further feature of the invention.

FIGURE 12 is a horizontal section on line XIIXII of FIGURE 11.

FIGURE 13 is a fragmentary view in section on the line XIl1XIII of FIGURE 11, illustrating a detail on an enlarged scale.

FIGURE 14 is a view illustrating the end part of an improved wet press in elevation, with parts in section.

FIGURE 15 is a transverse section on the line XV-XV of FIGURE 13.

FIGURE 16 is a partial front view showing the end of the wet press as shown in FIGURE 14.

FIGURES 1'7 and 18 are partial sectional views on the lines XVII-XVII and XVIII-XVIII of FIGURE 14, respectively.

The paper making machine illustrated comprises a main frame including upper and lower side members 1a, uprights 1b and cross members 1c in the form of suitably interassernbled channel sections in the present example. The main frame is pivoted at its rear end about about a transverse pivot axis 2 on a pair of brackets 3 upstanding from the floor. Secured to the under side of the frame in a central part of it is a fiat under-frame or base 4 made of interassembled sectional members and projecting laterally beyond one side of the main frame as shown at 4a in FIGURES 2, 3 and 4. The front part of the under-frame 4, 4a rests upon a suitable transverse support or cradle 5 in such a manner that the main frame of the machine is supported in an upwardly forwardly slanting position as is apparent from FIGURE 1. The angle of slope can be adjusted depending on the nature of the pulp to be treated, as by substituting for the cradle 5 another cradle of different height or interposing shims or spacer blocks between the cradle and the under-frame.

Secured to the upper part of the laterally projecting sub-frame part 4a in longitudinally spaced relation are uprights or arms 5 that serve to support within the main frame 1, in cantilever relation to said arms, an inner frame presently described, which contains a number of suction boxes disposed in a row lengthwise of the path of the pulp through the machine. The suction hoses are four in the illustrated example and are shown at 7, 8, 9 and 10 in FIGURES 1 to 5. The upper surfaces of said suction boxes define a continuous table or wire frame. The inner frame containing the suction boxes includes the lower and upper side members 13 and 14 respectively, and cross members or bulkheads 12, 12a and 12b which constitute extensions of the supporting arms which as shown in FIGURES 5 and 6 are bent inwards at their upper ends and extend the width of the inner frame. The lower side members 13 extend the full length of the row of suction boxes 7, 8, 9 and 10 (FIGURES 1 and whereas the upper side members 14 are limited in length to that of the last three boxes 8, 9 and 10.

The upper side members 14 are assembled to the cross members or bulkheads 12 by means of screws 15 some of which engage threaded holes formed in bosses 16 projecting from the cross members 12 while others are similarly connected to a bracket 17 projecting from one of the cross members 12, and yet other screws 15 connect with a box 118 secured to the end cross member 12b. The lower side members 13 of the inner frame are welded to the end cross members 12a and 12b and are further connected rigidly by way of angle members 18 to the intermediate cross members 12.

The inner frame thus supported in cantilever relation from the arms 6 has its longitudinal sides opened throughout their vertical extent and divided longitudinally by the bulkheads or cross members 12.

Supported from the end bulkheads 12a and 12b beyond the ends of the inner frame are bearings 19a and 19b respectively in which horizontal shafts 20a, 20b are journalled. Secured on the shafts 20a and 20b are drums 21a, 21b which serve as means for supporting and driving an endless wire cloth 22. Tension rollers 23a, 23b are suitably supported for engagement with intermediate points of the lower run of the wire cloth 22. The bulkheads 12 are suitably cut out as at 120 (FIGURE 6) to permit the wire 22 to pass through them.

As will be described later, the drums 21a, 21b are rotated in operation to drive the wire 22 in the direction indicated at f1.

The first suction box 7 traversed in the direction of travel f1 of the wire cloth 22 comprises a pair of channels 24a, 24b (FIGURE 5) equal in length to the angles 18 as shown in FIGURE 6. The channels 24a, 24b extend the full width of the inner frame from the front lower side member 13a to the rear lower member 13b. The channels 24a and 24b have their lower flanges assembled to the ends of a plate 25 and their upper flanges secured to a plate 26 the upper surface of which is flush with the lower surfaces of the upper side members 14 (FIGURES 5 and 6). Said plate 26 is formed with a series of transversely extending slots 27 extending over a length somewhat less than the width of the wire cloth 23 (FIGURE 2), so that the side margins of the wire cloth tightly engage the upper surface of plate 26 beyond the ends of the slots 27.

The suction box 7 has its front side i.e. the side adjacent side member 13a, sealed by a panel 28 formed with an inspection hole 29 normally sealed with a cover 30 provided with latching means31. On the opposite side, adjacent frame side member 13b, the box 7 is sealed by a panel 32 formed with an opening 33 over which is secured a suction nozzle 33a connectable with a source of suction. Secured to the upper wall of box 7 and depending therefrom are partial upper partitions 34, positioned between the adjacent slots 27 in the plate 26 over which the wire 22 slides. The suction box 7 is blocked in position in the inner frame by being tightly fitted between the cross members or bulkheads 12a and 12 (FIGURE 5).

The suction box 8 which follows box 7 in the direction of pulp travel comprises two channels 35a and 35b also equal in length to the angles 18. The channels 35a and 35b have their lower flanges interconnected by a plate 36 and their upper flanges interconnected by a plate 37 formed with a central opening somewhat shorter than the width of the wire 22 (FIGURES 2 and 5) as was the case for the slots 27. A support 39 having its ends secured to the respective channels 35a, 35b supports a set of three rolls 40 freely rotatable about spaced transverse axes, constituting a cradle on which are supported a further pair of freely rotatable rolls or cylinders 41, the upper parts of which are positioned within the opening 38 so as to engage the under surface of wire 22. The cylinders 40 and 41 are equal in length to the width of the opening 38. The suction box 8 has its front side, adjacent frame member 13a, sealed by a panel 42 and its opposite side sealed by a panel 43 formed with an opening 44 over which is attached a suction nozzle 44a connected with a vacuum source. The box 8 is held in position within the inner frame by means of screws 45 extending upwards through the side members 13 and applying the upper plate 37 of the box into engagement with the under face of the upper side members 14.

The third suction box 9 comprises a pair of channel members 46a and 46b, an under plate 47 and an upper plate 48 assembled thereto, said upper plate having an aperture 49 also a little shorter than the width of the wire 22. The box is sealed on the front side 13a by a panel 50 and on the opposite side by a panel 51 having an opening 52 surrounded by a suction nozzle 52a connected with a vacuum source. The box is held in position within the inner frame with screws 45 similarly to box 8,

The fourth suction box 10 is generally constructed and mounted in a similar manner to box 9, and corresponding parts have been designated with the same references.

The internal arrangement of each of the suction boxes 9 and 10 is illustrated in FIGURES 7, 8, and 9 and in FIGURE 3. As there shown, the channels 46a and 46b are interconnected within each box by braces 53 connected thereto by brackets 53a, and are further interconnected through three partition plates 54 and 54b secured thereto through flanges 54a. The plates 54, 54b serve to support a shaft 55 extending longitudinally of the box and blocked in position by means of nuts 55a engaging the end plates 54b. In each of the two spaces defined between the central plate 54 each of the end plates 54b are mounted flanges 56, one pair in each said space. The said flanges are mounted for free pivotal movement about the shaft 55 and each pair of them is connected at one side to a plate 56a engaging an elastic diaphragm 57 defining one end wall of a casing 58, the opposite end wall of which is formed by parts of the channel 46b; secured to said channel, within the casing, is a block 59 herein made of wood. A conduit 60 opens into the casing 58 and is outwardly connected to a source of pressure fluid, e.g. compressed air, whereby force can be applied to the diaphragm 57 to rotate the flanges 56 in an upward direction about shaft 55.

The flanges 56 are formed with cutouts in which are supported two shafts on which are secured rolls 61, there being one roll between the flanges 56 of each pair. The rolls 61 are disposed in a pair of parallel rows, forming a cradle on which is supported a roll 62 having convex ends 62a abutted against plates 63 from which project set screws 64 extending through the braces or spacers 53. The rolls 62 are disposed within the openings 49 and are equal in length with the latter, and are in engagement with the under face of the wire cloth 22 the upper face of which engages the larger-diameter press rolls 65, there being one press roll provided for each of the boxes 9 and 10. Each press roll is preferably provided around its periphery with a rubber or equivalent lining 66, and is secured on a shaft 67 driven through suitable means in the direction indicated by arrow f2. The shafts 67 (also see FIGURE 5) are carried on arms 68 pivoted at 69 (see FIGURE 1) in bearings 70 secured to the underside of the upper side member 1a of the main frame. The arms 68 are adjustable in position by means of screws 71 operated from handwheels 72.

As a modification of the construction described, the roll 62 cradled on the rows of rollers 61 within the boxes 9 and 10 may, as illustrated in FIGURE 10, be replaced by a hollow roll 73 having perforations 74 in its side wall.

A casing 118 (see FIGURE 5) secured to the forward end cross member 12b is internally connected to a source of pressure fluid, e.g. the same source of compressed air as that to which the casings 58 are connected.

The upper surface 118:: of casing 118 (FIGURE 5) is in engagement with the under face of the wire cloth 22 and is formed with a set of perforations 118b.

The main frame 1 has secured to its rear extremity, as referred to the direction f1 of travel of wire 22, projecting brackets 75 (see FIGURES 1, 2 and 4) serving to support trunnions 76 projecting from the sides of a supply or feeder casing 77 into which the pulp to be treated is delivered. The feeder casing 77 is internally provided with four pairs of partition walls 78a, 78b between the front wall 77a and rear wall 77b thereof, dividing said easing into upwardly flared passageways. Se cured to the front wall 77a are four tubes 79 which open in between the partitions 78a, 78b of each pair. The tubes 79 extend from a manifold 80 to which pulp is supplied by way of a conduit 81.

The casing 77 is followed by a feeder passage or channel defined by plates 82 to 87, and extending along a sinuous path. This passage includes a lower generally horizontal plate 84 secured to and extending from a point of the front Wall 7712 of feeder 77 somewhat below its top, an upper generally horizontal plate extending from the top of the rear wall 77:: and spaced above plate 84 to define therewith a horizontal passage section, a plate 85 attached to the front end of lower plate 84 and extending upwardly from it, and a plate 82 attached to the front end of upper plate 83 and extending upwardly from it to define with plate 85 a vertical passage section. Further, the passage includes a plate 86 attached to the upper end of plate 85 and extending forwardly from it, and a plate 87 spaced above plate 86 to define with it a forwardly extending passage section. The front end of plate 86 lies flush with the upper surface of the wire 22 at the point where said wire is supported by the drum 21a. The upper plate 87 rather than being attached at its rear end to the plate 82 is mounted for vertical adjustment by means of bolts 88 (see FIGURE 5) positionable in vertical slots 89 formed in side flanges of the plate 87.

The side walls 77 of the feeder box or hopper extend up to the level of the rear end of the lower plate 86. Extending beyond each of these side walls in the same plane as it is one side run 90a of a related endless belt 90 trained around pulleys 91 supported on a frame 92 secured to the side walls of the hopper. The endless belts 90 are engaged by tension rollers 93 biassed by springs 94 urging the two sides or runs of each belt 90 toward each other. The belts 91 are driven at a linear velocity equal to that of the wire cloth 22 in the same direction (f1) as it and serve as means for confining the pulp issuing from the hopper within the width dimension of the wire 22.

Projecting from the top of plate 82 is a bracket 95 to which is pivoted a :clevis 96 from which extends a screw rod 97 extending through a guide bushing 98 pivoted on a transverse axis from a fixed bracket 99. Threaded on the screw rod 97 is a nut 100 to which is secured a handwheel 109a. Manual rotation of the handwheel to displace the screw rod 97 axially eg in the direction f3 (FIGURE 1) will rotate the feeder togethetr with the belts 90 bodily around the trunnions 76 relatively to the brackets 75. This action serves to move the plate 86 and belts 90 away from the wire 22 for servicing especially for the purpose of replacing the wire when desired.

The apparatus as so far described operates as follows. The aqueous pulp of fibre material is delivered to the base of feeder 77 through the pipe 81 (FIGURES 1 and 4) manifold 80 and inlet tubes 79 and rises up the flaring passageways defined between the partitions 78a, 78]), then passes into the sinuous passage defined by the plates 82 to 87, in which any turbulence present in the stream of pulp subsides owing to the sinuous nature of the passage and quiescent flow conditions are imparted to the stream. The pulp spreads over the surface of wire cloth 22 to form a sheet laterally confined by the belts 9b which accompany the wire in its slowly rising path of advance. The liquid is drawn out of the pulp through the Wire 22 by the suction present in the sequence of suction boxes. In the last two suction boxes of the series the action of the vacuum combines with that of the press rolls 62, 65. Beyond the last suction box 10 the drained pulp is subjected to the action of compressed air jets issuing from the casing 118 and serving to detach the pulp from the wire. The sheet of pulp is then collected in any suitable way e.g. in a pit, not shown, located under the end drum 21b One typical application of the above described apparatus is to the production of kraft pulp by the sulphate process. The cellulose fibre at the outlet from the digesters is suspended at a concentration in the range of from 5 to 10% in an aqueous medium rich in valuable constituents known as black liquor. This black liquor is desirably collected both for the recovery of valuable inorganic salts therefrom and to extract organic constituents also for recovery and/or for burning them in order to avoid polluting the river waters used for disposal.

In this application the main frame of the apparatus may be mounted at an inclination to the horizontal plane providing a slope of about 10% for the wire, and the wire may be driven at a linear velocity within the range of from 15 to 35 meters per minute. The suction pumps or fans serving as sources of vacuum are controlled to provide increasingly high degrees of suction in the se quence of suction boxes, one suitable pattern being from 50 to cm. water in suction box 7, from 120 to 150 cm. water in box 8, and from 250 to 400 cm. water in each of the final boxes 9 and 10. The rolls 62, 65 are adjusted to apply to the pulp in the box 9 a pressure of from 10 to 15 kg. per linear centimeter, and in box 10 a pressure of from 15 to 25 kg. per linear cm. The rolls 65 are lined peripherally with a coating of rubber having a hardness number of from 70 to Shore.

By this procedure a kraft pulp weighing about 1000 grams per square meter can be obtained with a dryness of from 30 to 35%. Such a degree of dryness represents a considerable advance over what is obtainable wtih priorart apparatus with which dryness degrees of about 15% were all that could be obtained. In practice, a series of apparatus units similar to the one described can advantageously be used, with the drained pulp being replaced in suspension between successive units, whereby substantially all of the black liquor content of the pulp can be extracted.

According to an important feature of the invention, the frame of the Fourdrinier machine is adapted to have a wet press mounted thereon, said wet press generally comprising a pair of rolls mounted one above the other and having an endless belt or felt fed between them. The pulp sheet from the Fourdrinier is picked up by the felt and fed thereby between the two rolls to be thereby subjected to a controlled pressure for draining the pulp, the water draining out through the felt ahead of the lower roll and being discharged. The pressure rolls or cylinders are advantageously mounted in a manner similar to that described with reference to FIGURES 7 to 10 in connection with the suction boxes 9 and 10 of the Fourdrinier.

As described each of the lower rolls 62 (or 73) is supported on a cradle formed by a row of rollers 61 whereby the vertical position of the roll 62 (or 73) can be adjusted through suitable pneumatic actuator means as described. Similar advantages can be derived if the Wet press used is constructed according to the modified embodiment now to be described with reference to FIG- URES 11 to 18.

As shown in FIGURES 11 and 12 each of the upper side members In of the main frame has a channel extending from its forward end at a downward angle to provide an auxiliary end frame for supporting rolls 121 over which an endless belt or felt 122 of a wet press is trained. Projecting upwards from the lower side members 1a are L-shaped brackets 123 to the upper ends of which are pivoted crank levers 124, 129. The generally horizontal arms 124 of the crank levers are arranged to provide bearings for a shaft on which is mounted a cylinder 125 forming the upper roll of the wet press and having a length at least equal to the width of the Fourdrinier. The lower cylinder of the wet press is provided by a hollow roll 126 having a perforate wall, and described more in detail presently with reference to FIGURES 13 to 18. The cylinder 126 is equal in length tocylinder 125 and is supported at its ends in bearings supported on base supports 127 projecting up from the lower arms of the L-brackets 123. An endless belt or felt 122 is supported as later described so that its upper run extends between the cylinders 125 and 126. The width of the gap between the cylinders is adjustable by means of set screws 128 engaging threaded holes in the upstanding legs of the brackets 123 and having their tips engaging the depending legs 129 of the crank levers 124-129. Further, a screw rod 130 is threaded through a nut pivoted on a lug projecting from a side of the upright bracket arm 123 and has a point pivotally attached to the lower end of the depending arm 129. Rotation of the screws 130 makes it possible to raise the upper cylinder 125 when required to service or replace the felt 122. In the normal operating condition the screws 130 keep the arms 129 applied in engagement with the ends of screws 128.

Referring now to FIGURES 13 to 18, it will be seen that within the perforate hollow cylinder 126 there extends a pair of longitudinal channels 131 disposed with their flanges directed outwardly and having their lower flanges interconnected by a flat web 132. The sectional assembly 131-132 is greater in length than the cylinder 126, and its ends projecting beyond the ends of the cylinder are secured to the aforementioned base supports 127. Secured to the upper surfaces of the upper flanges of channels 131 are the horizontal flanges or angles 133 each having a small channel 134 secured to the top of the inner surface of its vertical flange. Sealing strips 135 are inserted into the small channels 134 and project upwards therefrom into engagement with the inner surface of cylinder 126 to define a sealed enclosure of generally rectangular cross section extending the full length of cylinder 126. The channels 131 are interconnected at points spaced along them by spacers 131a each formed with a central bushing 135 through which a short rod 136 is slidably positioned. Each rod 136 has a bracket 137 secured to its upper end, said bracket having spaced upstanding flanges serving to journal in parallel spaced relation the pivot pins of a pair of rollers 138. The rods 136 each have a plate 139 secured to its lower end and resting on an elastic diaphragm 140 extending across the width of the web 132 while being maintained spaced above said web so as to define with the latter a flat chamber which is connected by way of a conduit 141 with a source of pressure air.

Resting freely on the rollers 138 is a roll 142 the uppermost generatrix of which is held in resilient engagement with the inner surface of cylinder 126. Thus it will be seen that in this embodiment as in the one described with reference to FIGURES 7 to 10, the roll is supported in accordance with the invention on cradling means that are vertically movable.

The roll 142 is driven in rotation in the direction f4 by way of a suitable drive transmission 143 (FIGURE 12) connecting with one end of the roll. Hence the perforate cylinder 126 will be positively driven in the same direction f4 about its axis. The upper cylinder 125 is mounted for idle rotation about its axis. Consequently the felt 122 will act to feed the sheet of pulp 22 in the direction 1. The cylinder 126 is guided in its rotation by a first set of rollers 144 engaging its inner surface journalled on horizontal longitudinal axes in opposed pairs .being supported from the respective channel members 131 at spaced points along the cylinder, and a second set of single rollers 145 also supported for rotation from the channels 131 intermediate the paired rollers 144. All said rollers are supported in flanges such as 146 mounted across the side flanges of each channel member 131. A small-diameter roll 147 equal in length to the cylinder 126 rests under its own weight on the inner wall surface of the cylinder at the lowermost point thereof, being guided at its ends for free vertical movement in slotted plates 147a depending from the web 132. The axial positioning of the cylinder 126 is effected by rollers 148 (FIGURE 12) supported for rotation about transverse axes in engagement with each of the end surfaces of the cylinder 126. Desirably the end portions of the cylinder 126 are provided with suitable reinforcing hoops, not shown.

Extending through the cylinder 126 near its bottom is a pipe 149 externally connected to a source of water under pressure, and having spaced perforations in its walls for at all times discharging jets of water and/or cleaning agent against the inner wall surface of cylinder 126 to prevent clogging in the perforations thereof. The water discharged from the cylinder 126 is collected in a trough 150 underlying the cylinder and is disposed of.

As earlier noted the channels 131, web 132, angles 133 and sealing strips 135 define an inner sealed enclosure in the cylinder and this enclosure is connected through suitable means to a source of suction. The suction generated in this enclosure adjacent the surface of the pulp sheet moving past the presser cylinders enhances the draining of the pulp and the water drained off is discharged from the end of said enclosure by means not shown. A sprayer pipe 151 (FIGURE ll) is preferably provided to spray pressure water against the inner surface of the felt to keep the felt free of fibre fragments ten-ding to cling to the outer surface of the felt.

A pair of small presser rolls 152 is further provided to act on the opposite sides of the felt ahead of the outlet end of the Fourdrinier to drain the felt free from excess liquid.

It will be understood that a great many modifications may be introduced into the embodiments of the invention illustrated and described without exceeding the scope of the invention. Various of the features disclosed may be applicable in various combinations independently of other features. The number and design of the suction boxes in the Fourdrinier shown can be varied from what is illustrated especially in FIGURES 1 and 3, although preferably the general arrangement shown, wherein the upper presser rolls 65 are combined with the lower rolls 6-2 only in one, two or more of the end suction chambers of the sequence provide, is retained. Certain suction boxes or chambers of the sequence, especially those at the supply end of the wire cloth, can be provided as ordinary suction chambers, without the improved rolls of the invention.

What I claim is:

1. A fibre pulp processing machine comprising in combination a main frame; supporting drum means mounted adjacent opposite longitudinal ends of said frame for rotation about transverse axes; an endless wire cloth trained about said drum means and having an upper surface arranged to support wet pulp thereon; means for rotating the drum means to advance said wire cloth with said frame defining a sequence of suction chambers distributed longitudinally underneath said surface of the wire cloth; said suction chambers having upper walls underlying said cloth and transversely elongated apertures in said walls; rolls positioned in said chambers transversely thereto having upper portions extending through said apertures into engagement with the under surface of said cloth; supporting means for said rolls in said chambers including cradling means engaging lower portions of the rolls to permit rotation thereof and means for resiliently biassing the cradling means upwards to urge the rolls into engagement with said cloth, including means for adjusting the vertical elevation of said cradling means; and an inner frame, means supporting said inner frame within said main frame, means mounting said supporting drum means from opposite ends of said inner frame, said end less cloth being trained around said inner frame, and means for removably supporting said suction chamber means in said inner frame for removal therefrom and insertion thereinto through a side of said inner frame.

2. The machine claimed in claim 1, having a blower casing supported from a delivery end of said inner frame and positioned to blow compressed air against the under surface of said wire cloth and means connecting the blower casing to a source of compressed air.

3. The machine claimed in claim 1, wherein said means supporting the inner frame comprise longitudinally spaced supports extending from a common side of said main frame and projecting into said main frame and means supporting the inner frame from said arms in cantilever fashion, and said suction chamber means are mounted in said inner frame for removal and insertion through the opposite side of said inner frame and said main frame.

4. In fibre pulp processing apparatus, a wet suction press assembly comprising a frame, endless felt means movably supported from said frame and arranged to receive pulp on an upper surface thereof, a hollow and perforate lower press roll and an upper press roll supported from said frame for engagement with respective opposite surfaces of the felt means on substantially coincident lines, the supporting means for said lower press roll including a generally horizontal frame member extending through the hollow in the lower roll and having projecting ends secured to the frame, said frame member having a cavity defined therein, a plurality of rollers rotatably supported from said frame member within said hollow and engaging spaced points of the inner periphery of said lower press roll for guiding same in rotation, the cavity in said horizontal frame member being upwardly open to communicate with an upper portion of the inner wall periphery of said perforate lower roll, seal means on said horizontal frame member engaging said inner wall periphery of the lower roll around the walls of said cavity, means participating with said seal means to seal said cavity except for the perforations in said lower roll, and suction means connected with said cavity for drawing off a liquid constituent through said perforations and felt from said pulp.

5. The wet suction press claimed in claim 4, including an inner roll mounted for rotation within said cavity of the horizontal frame member about an axis parallel to that of said roll and engageable with an upper portion of said inner peripheral wall of the lower press roll, means in said cavity :for cradlingly engaging an under portion of said inner roll, to support same for rotation, and means for resiliently biassing said cradling means upward including means for adjusting the elevation thereof.

6. The wet suction press claimed in claim 4, including an inner roll mounted for rotation within said cavity of the horizontal frame member about an axis parallel to the axes of said rolls and engageable with an upper portion of said inner peripheral Wall of the lower press roll, rollers in said cavity mounted for rotation about spaced axes parallel to said first mentioned axes and cradlingly engaging an under portion of said inner roll to support same for rotation, means supporting said rollers from said frame member, and fiuid pressure actuator means connected to said roller-supporting means for resiliently biassing said rollers upward and for adjusting the elevation thereof.

7. The wet suction press claimed in claim 6, wherein said roller supporting means comprise a support, means for pivoting said rollers about said spaced axes at the top of said support, means defining a sealed pressure chamber in the bottom of said cavity including a flexible diaphragm defining the top of said pressure chamber and engaging the base of said support, and means connecting said pressure chamber to a source of controllable air pressure.

References Cited by the Examiner UNITED STATES PATENTS 1,853,625 4/ 1932 Lapeyrouse '162--350 2,270,465 1/ 1942 Nash 1623 14 2,950,507 8/1960 Keyser. 3,035,512 5/1962 Beachler 17O 3,084,740 4/ 1963 Carrel 162-37 3 FOREIGN PATENTS 546,471 9/ 1957 Canada. 1,018,583 10/1952 France.

889,244 2/ 1962 Great Britain.

OTHER REFERENCES Pickartz, German application No. R 14,124, published February 1956.

DONALL H. SYLVESTER, Primary Examiner.

J. H. NEWSOME, Assistant Examiner.

Claims (1)

1. A FIBRE PULP PROCESSING MACHINE COMPRISING IN COMBINATION A MAIN FRAME; SUPPORTING DRUM MEANS MOUNTED ADJACENT OPPOSITE LONGITUDINAL ENDS OF SAID FRAME FOR ROTATION ABOUT TRANSVERSE AXES; AN ENDLESS WIRE CLOTH TRAINED ABOUT SAID DURM MEANS AND HAVING AN UPPER SURFACE ARRANGED TO SUPPORT WET PULP THEREON; MEANS FOR RATATING THE DRUM MEANS TO ADVANCE SAID WIRE CLOTH WITH SAID FRAME DEFINING A SEQUENCE OF SUCTION CHAMBERS DISTRIBUTED LONGITUDINALLY UNDERNEATH SAID SURFACE OF THE WIRE CLOTH; SAID SUCTION CHAMBERS HAVING UPPER WALLS UNDERLYING SAID CLOTH AND TRANSVERSELY ELONGATED APERTURES IN SAID WALLS; ROLLS POSITIONED IN SAID CHAMBERS TRANSVERSELY THERETO HAVING UPPER PORTIONS EXTENDING THROUGH SAID APERTURES INTO ENGAGEMENT WITH THE UNDER SURFACE OF SAID CLOTH; SUPPORTING MEANS FOR SAID ROLLS IN SAID CHAMBERS INCLUDING CRADLING MEANS ENGAGING LOWER PORTIONS OF THE ROLLS TO PERMIT ROTATION THEREOF AND MEANS FOR RESILIENTLY BIASSING THE CRADLING MEANS UPWARDS TO URGE THE ROLLS INTO ENGAGEMENT WITH SAID CLOTH, INCLUDING MEANS FOR ADJUSTING THE VERTICAL ELEVATION OF SAID CRADLING MEANS; AND AN INNER FRAME, MEANS SUPPORTING SAID INNER FRAME WITHIN SAID MAIN FRAME, MEANS MOUNTING SAID SUPPORTING DRUM MEANS FROM OPPOSITE ENDS OF SAID INNER FRAME, SAID ENDLESS CLOTH BEING TRAINED AROUND SAID INNER FRAME, AND MEANS FOR REMOVABLY SUPPORTING SAID SUCTION CHAMBER MEANS IN SAID INNER FRAME FOR REMOVAL THEREFROM AND INSERTION THEREINTO THROUGH A SLIDE OF SAID INNER FRAME.

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