BE664492A - - Google Patents

Description

       

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  IMPROVED PRESSES FOR PAPER MACHINES AND CYLINDERS EQUIPPING THESE PRESSES.



   The present invention relates to an improvement in devices intended to extract a liquid from a strip material containing liquid, and more particularly relates to improved paper machine presses and press cylinders for equipping these machines.



   Although the present invention can have a large number of uses in different fields, it is particularly advantageous in the art of papermaking and will be described primarily in connection with this technique. In a tape press, such as is used in a papermaking machine, a web clamping zone is formed between two opposed press rolls, and a moving web of paper is passed through this clamping zone. contact with a felt.

   In prior art structures, the press rolls used were smooth, or

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 well the cylinder covered by the felt in the clamping area was formed with a perforated casing having a suction fitting facing the clamping area to help remove moisture from the tape through the felt, cam is the case in conventional vacuum presses. In other instances, as disclosed in Walker U.S. Patent No. 3,023,805 of March 6, 1962, the felt-covered press cylinder includes a non-perforated, rubber-covered casing pierced with blind holes to accommodate at least temporarily the water squeezed from the strip through the felt in the tightening area of the strip.

   In still other web presses, the press cylinder covered by the felt has other types of blind hollows or a fine pore structure, or a structure in the form of a woven fabric wound on top of the cylinder. , or parts of the cylinder surface may have non-perforated envelopes, and in such cases the felt ordinarily serves to dry the web by removing a significant amount if not all of the water which is to be removed from the web at the bottom. clamping area. This then requires a separate operation and / or apparatus to rid the felt of water before returning it to the band tightening area.

   In the French patent application filed the same day as the present in the name of the same applicant, and entitled, "Mechanism and method for the removal of moisture from the felt, in a paper machine", certain improvements to the devices intended for removing water from the felt at a separate "felt only" wiping zone, are described in further detail in said

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 Described herein are some press cylinder structures for removing water from the felt at a felt-only spin zone, in a compartmentalized press as well as for helping to remove water from the felt at the web press (i.e. (i.e. to help remove from the felt the water that was squeezed from the tape through the felt at the tape clamp area).

   The present invention relates to presses comprising a grooved press cylinder, and the grooved press cylinder itself or with certain ancillary accessories functioning remarkably in combination with the grooved press cylinder,
Heretofore, some press arrangements have been used to attempt to remove the water from the felt at the web clamp area. Each of these arrangements has required a structural modification with respect to a press clamp area. smooth, either by incorporating additional materials in the clamping zone, or by modifying the smooth press cylinder which supports the felt in this zone, for example by replacing the cylinder with a suction cylinder.

   The suction cylinder is capable of giving excellent results for certain uses, but it must be realized that the manufacture of the perforated bodies of suction cylinders, to which must be added the essential auxiliary equipment to maintain in the cylinder connection them desired depressions or partial voids is relatively expensive. In addition, the use of a connection on the suction cylinder, inside the perforated body of the cylinder, makes it impossible to use conventional or improved devices preventing the cylinder from deflecting and

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 which are mounted inside the body to maintain completely uniform pressures in the tightening zone.

   The relatively large dimensions of the perforations of the suction cylinder (plus the pressure difference created by the suction fitting at the periphery of the cylinder), facilitate the removal of water from the felt, but in cases which involve the use of light weight markers and / or when producing relatively sensitive paper tapes or high quality paper tapes, these tapes tend to exhibit what is known as "shadow marks" which originate from these tapes. cylinder perforations, even when covered with felt in the clamping area of the suction press.



   In 16s presses recently studied and called "compartmentalized presses" efforts have been made to avoid the use of suction press cylinders at the web clamping area, by replacing these cylinders with a smooth press cylinder or with cylinders. of the general type comprising unperforated walls but covered with a multitude of blind holes, small blind hollows, pores, etc. These cylinders having such hollows are used mainly to avoid overloading the clamping of the band with water and to allow some of the water to lodge in the hollows in this area although the water load in this area. the hollows generally return almost completely to the felt on the exit side of the band clamping zone.

   Other various press roll arrangements, including suction press rolls, were then used on a separate press for felt alone.

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 to rid the felt of water in an amount necessary to prepare it and allow it to return to the tape clamping area in such a compartmentalized press assembly. The present invention relates directly to improvements not only to the structure of the web press but also to the structure of the press for felt alone, which are due mainly to the use of certain grooved press rolls in these structures. .

   An important advantage of such press rolls, which have grooves generally aligned on their peripheries or on their circumferences, is that the cylinder surfaces in the clamping region are connected to the ambient atmosphere through the grooves. so as to facilitate drying of the press cylinder in the clamping area. It will be appreciated that with such grooved press cylinders, the grooves are applied to a wall devoid of perforations which can be mounted with a device preventing it from deviating and without expensive auxiliary suction equipment. Still other important advantages can be obtained by using particular grooved cylinder structures and auxiliary equipment which will be described in more detail herein.



   Consequently, the present invention proposes in particular to provide $
An advanced press assembly for removing liquid from liquid-containing web material (which may be wet felt alone or in combination of felt and tape)
An advanced compartmentalized press assembly in which the rollers of the belt press and / or press for

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 felt alone have improved structure and functioning,
An improved press structure in which the advantages of "anti-deflection" cylinder mountings, inexpensive cylinder structures, and simplified structures can be utilized for removing water from a wet belt or. a felt and / or the surface of the press cylinder itself;

   
An improved grooved press cylinder structure which is inexpensive to manufacture, particularly useful and safe in its function of removing water, and which can be easily maintained in operating condition, and
Improved devices intended to cooperate with such a grooved cylinder for cleaning and maintaining the latter in good condition. rid it of water during its operation, and advantageously use this function of removing water from the latter,
Other characteristic objects and advantages of the present invention will emerge from the detailed description which follows, with reference to the accompanying drawings, in which.



   Figure 1 is a schematic side view of a press mechanism according to the present inventions
Figure 1A is a partial detail view taken along the line A-A of Figure 1;
Figure 2 is a partial detail sectional showing part of the clamping area of the prior art vacuum press,
FIG. 3 is a view similar to FIG. 2, showing part of the clamping zone under a press using blind holes drilled on a cylinder, according to the prior art $

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Figure 4 is a view similar to Figures 2 and 3 but showing a press clamping area according to the present invention;

   '
Figure 4A is a partial axial section of detail taken by line A-A of Figure 4,
Figure 4B is a partial enlargement in section, taken on the part surrounded by a circle designated by IV B in Figure 4A;
Figure 5A is a partial axial section, similar to that of Figure 4A but showing another embodiment of the present inventions
Figure 5B is a partial enlargement taken in Figure 5A roughly on the part surrounded by a circle and marked V B;
Figures 6 and 8 are elevational views, essentially schematic, of press assemblies according to the present invention,
Figures 7 and 7A are detail, partial, and enlarged views, taken from the circled parts of Figure 6, and marked VII and VII A, respectively.



   Figure 7B is a slight enlargement of the view of Figure 7A showing a cleaning device of the present invention and Figure 7C is a view of Figure 7B taken along the line VII C-VII C thereof ,
Figure 9 is a substantially schematic elevational view of a compartmentalized press assembly according to the present invention.

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Figure 10 is a substantially schematic elevational view of a compartmentalized hot press assembly according to the present invention;

   
Figures 11 and 12 are elevational views, substantially schematic of different sets of compartmentalized presses according to the present invention, and
Fig. 13 is a substantially schematic elevational view of the press section of a paper machine, showing the universal character of the grooved cylinder of the present invention.



   Referring to Figure 1, it can be seen that a press assembly, generally indicated by the numeral 10, comprises a loop-shaped press felt 11 mounted on guide rollers 11a, 11b, 11c, 11d , lle and a tension roller llf. A first smooth press cylinder 12 and a second lower press cylinder 13 form a first band clamping zone N-1 receiving the felt 11 and a wet band W-1, in order to transfer the water from the band W-1 felt 11 in this clamping zone Nl. A third press cylinder 14 and a fourth ¯ / lower press cylinder 15 form a second spin zone N-2 for felt alone, Press cylinders 13 and 14 are inside the loop of felt 11 and the press rolls 12 and 15 are outside this loop.

   The second press cylinder 13 is formed of a body or basic structure devoid of perforations as in the case of the blind hole cylinders of the prior art, such as those described in the aforementioned patent No. 3,023,805 and in French patent application

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 already mentioned.

   The second press cylinder 13 thus differs from the conventional perforated suction cylinder (which has perforations such as those shown here in Figure 2) and the cylinder 13 has a top which has a large number of fine recesses for retaining the press cylinder. water between the surfaces of the flats of the partitions which support the felt 11 in the clamping zone Nl, The cylinder 15 has a similar top structure, More particularly, with reference to Figure 1A, the structure of cylinders 13 and 15, which is shown in section at 15a in FIG. 1A, has a number of flattened surfaces of partitions aligned at the periphery (or generally at the circumference) with relatively fine or narrow grooves 15c between the surfaces of the flats of the partitions,

   intended to receive the water coming from the felt 11 at the wiping zone (for example at the wiping zone N-2 for the cylinder 15). One realizes that the crosses 15b have a sufficient width and that the grooves 15c are sufficiently narrow to allow the felt 11 to be easily supported in the wiping zone N-2 (or in the corresponding clamping zone N-1 by the cylinder 13), so that water can be squeezed out of the felt 11 and go into the grooves 15c, but the felt 11 itself is not compressed in the grooves 15c to any significant extent;

   and in the case of the clamping zone N-1, that the felt 11 is not deformed or temporarily modified in any other way, passing through the clamping zone N-1 which would produce pronounced shadow marks or very pronounced on the W-1 strip coming from the relief of the flats and grooves on the surface of the cylinder 13.



   Referring in particular to the operation of the press cylinder 15, it can be seen that at a point remote from the outlet side of

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 the spinning zone N-2, the press cylinder, grooved 15 is first subjected to a water jet 15d, then to the action of a scraper 15e fitting into the grooves 15c and operating in conjunction with the water jet 15d to sweep and / or scrape fibers, fines, water, etc. and bring them out of the grooves 15c. As can be seen in FIG. 1A, in which the scraper 15e is shown partially but clearly visible, it is provided with a certain number of fingers 15f which function in the very vicinity of the grooves 15c, to scrape or sweep d 'efficiently all the solids and get them out of the grooves 15c.

   The water jet 15d naturally contributes to this sweeping action and to keeping the front face of the scraper 15e clean, the rinsing water flowing into a conventional trough 15g. A 15h rotating brush is also mounted to brush the water droplets and push them out of the grooves in a region remote from the spin zone N-2. The brush 15h can be replaced by flexible sheets or by similar elements intended to sweep the interior of the grooves 15c and to brush the droplets out. Finally, a jet of air or an air scraper 15i spread over the periphery of the brush cylinder 15h, finishes removing the moisture from the grooves 15c.

   It will be appreciated that the air scraper 15i also serves to wipe and completely dry the surfaces of the wall flats 15b almost immediately on the entry side of the area.
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 jy 5 N-2 spin.



   From this point of view, it should be noted that the "longitudinal" direction indicated here, always refers to the direction of travel of

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 tape or felt or other object indicated as following that direction, while the "transverse" or "cross-machine" direction or direction is at right angles to the longitudinal direction generally in the plane of the felt of the band to which we relate.

   With respect to each tightening or wringing zone (for example N-1 or N-2), the "entry" side of the zone is the side of the zone along which the band and / or the moving felt approaches; while the "exit" side of the clamping or wringing area is in the longitudinal direction with respect to the entry side of any clamping area and is on the side of the clamping area along which the web or strip is felt move longitudinally away from this area. Likewise, the inlet and outlet sides of any part of the auxiliary equipment, such as the air scraper 15i are, respectively, the direction in which the rotating surface of the cylinder approaches and the direction in which the cylinder is approached. surface of the rotating cylinder leaves this air scraper 15i.

   Thus, for example, the brush 15h is on the inlet side of the air scraper 15i and the wiping zone N-2 is on the outlet side of the air scraper 15i. On each of the drawings given here, the arrow heads indicate the direction of travel of the elements on which they are placed.



   As regards the cylinder 13, it can be seen that it is also provided with a water jet 13d on the side of the cylinder 13 rotating downwards, preferably cooperating with a scraper
13th (on the outlet side of it) fitting into the grooves on the surface of cylinder 13. There is also a 13g trough

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 and on the upward rotating side of cylinder 13, a suitable brush 13h and air jet or air scraper 13i (on the outlet side of the brush 13h) complete the removal of moisture from the grooves and surfaces flats of partitions by sending water into the trough 13g.



   Referring now to Figure 4A and Figure 4, it is seen that Figure 4A is a sectional detail view similar to Figure 1A, except that it is taken along the line IVA-IVA of figure 1 at the clamping area N-1, so as to partially show the upper cylinder 12, the lower cylinder 13, the strip W-1 (all in section) and the felt 11 in full view for simplicity the drawing. It can be seen that the cylinder 13, like the cylinder 15 of FIG. 1A has grooves 13c and) flats surfaces of partitions 13b of approximately equal dimensions (the surfaces of flats of partitions 13b forming the peripheral cylindrical surfaces of edges also designated by the reference 13b).

   Figure 4 is another partial detail view in section along the line IV-IV of Figure 4A and Figure 4 shows the upper cylinder 12, the lower cylinder 13 (with some elements shown in section and others cut away), tape W-1 and felt 11 (in full view, with an arrow indicating the longitudinal direction). The groove 13c is shown in figure 4 as constituting a part of the set of ridges 13b and grooves 13c alternating and aligned on the circumference of the cylinder 13, but the detail of figure 4 is taken from a part of the set of the press so small, that the curvatures of the cylinders 12 and 13, as well as those of the bottoms of the rain @@ es 13c are not highlighted.

   In itself

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 Referring to Figure 4B however, it is seen that the grooves 13c each have a very small or narrow axial dimension 16 at their entrance or at their peripheral part which is aligned with the cylindrical outer surfaces 13b or surfaces of the ridges partitions, these partitions d 'ridge having an axial dimension 17 which is shown in Fig. 4B as being approximately the same as the axial dimension 16 of the grooves 13c at or at the entrance to the outer periphery,

   It can also be seen that the grooves 13c are between radial walls 13c-1 and 13c-2 which extend parallel to one another and which are spaced at least at the axial dimension 16 over the large radial distance of their depth 18 which is greater than the axial dimension 16 of the inlets of the grooves and the axial dimension 17 of the partitions (in fact, it is about twice the one and the other axial dimensions 16 or 17).



   Referring now to FIG. 6, it can be seen that it represents a press assembly generally indicated by the reference 20, which comprises a significant improvement on the embodiments of the present invention indicated so far. to the clamping zones N-1 and N-2 of figure 1. The press assembly 20 comprises a smooth upper press cylinder 21 whose structure is comparable to that of the smooth press cylinder 12, and a lower press cylinder grooved 22 comparable in some respects to the grooved press rolls 13 and 15 described above.

   The press rolls 21 and 22 form a press clamping zone which receives a wet web W-6 in contact with the smooth press roll 21 and which is carried by a felt 23 passing over guide rollers 24a and 24b, this 23 felt moves with the W-6 strip in contact with it, ...

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   on the inlet side, in the pressure zone, and on the outlet side of the clamping zone N-3, as shown here, The grooved cylinder
22 is provided with a trough indicated generally at 25 and shown as formed of three parts 25a, 25b and 25c.



   . The grooved cylinder 22 is shown partially in detail in Figures 5A and SB (with Figure 5A taken approximately along the line VA-VA of Figure 6), and the grooved cylinder 22 is seen to have a top 22a in solid elastomer (rubber) on a 22x envelope in malleable iron without perforations. The top 22a may be formed of stainless steel which is preferable in some cases and also allows fine grooves 22c to be cut between partitions 22b which in size and shape are shown in Figures 5A and 5B.

   Referring more particularly to Figure 5B, it will be seen that the top 22a of the grooved cylinder 22 is shown in the view without hatching to facilitate its detailed description, the grooves 22c are shown here as having a substantially uniform axial dimension 26 which is 0.635 mm between cylindrical (smooth) partitions 22b on ridges alternating with the grooves 22c, these partitions 22b having an axial dimension 27 of 2.54 mm, that is to say about four times the dimension 26 of the entry of the groove, resulting in an open contact area of the grooved cylinder 22 of approximately 20%. The grooves 22c extend radially inward to a depth 28 by 3,

  175 mm which is greater both than the axial dimension of the grooves 26 and that of the partitions 27; these grooves 22c are comprised between walls extending radially and in parallel 22c-1 and 22c-2, axially spaced apart by the distance
26, axial dimension of the inlet of. the groove or which is superior

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 at this dimension (but not more than 100% because of the inconvenience of hollowing out the partitions 22b), so that the water which enters the peripheral inlets of the grooves 22c is not constrained to flow radially inwardly of the groove 22c.



   Referring again to Figure 6, it can be seen that the water expressed from the strip W-6 through the felt 23 at the clamping area N-3 goes into the grooves 22c of the grooved cylinder 20 and for the most part is carried away from the felt 23 on the exit side of the clamping zone N-3. The first trough portion 25a is mounted as close as possible to the exiting felt 23 and the exit side of the cylinder 22 so as to catch water droplets excited by the centrifugal force of the grooves 22c immediately upon exiting the trough. the clamping zone N-3. However, the grooves 22c resist the centrifugal force which tends to eject these droplets out of the cylinder 22, particularly at slow working speeds.

   However, at higher working speeds of 150 m per minute and more, the tendency of the narrow grooves 22c to resist the expulsion of water from the cylinder 22 as a result of the centrifugal force is overcome at least. in part, and the trough portion 25a acts to reduce the possibility of the underside of the W-6 rewetting as a result of this ejection.



   However, a large amount of water remains trapped in the narrow grooves 22c on the grooved cylinder 20 until this cylinder passes in front of a sweeper 29, which is remarkably simple, and which is simply constituted by a flat sheet d 'a moderately elastic material such as

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 sheet of metal 29a fixed to a transverse bar 29b, pushed continuously transversely against the partitions 22b at the periphery of the cylinder 22.

   In this way, the sheet 29a of the sweeper does not enter the grooves 22c but simply presents an axially continuous surface on the transverse peripheral dimension of the cylinder 22 along a transverse line of contact (i.e. actually on a limited peripheral contact surface), on which the sweeper 29 ', extends axially continuously from the exit side of this contact line L-1 and slowly separates or diverges' from the periphery exiting from the grooved cylinder 22 so as to produce a pumping effect, a withdrawal of the water contained in the grooves 22c (which in reality is swept from the grooves 22c by the air which rushes in to fill the partial vacuum produced by the pumping action of the sweeper 29).

   Water which has been held in the grooves despite the combination of centrifugal force and gravity, on the downward rotating side of the grooved cylinder 22, is thus roughly completely swept away from the grooves 22c and for a large part, goes into the second or lower part 25b of the trough.



   Part of the water which is thus withdrawn from the grooves 22c remains on the partitions (in the form of a meniscus), as well as the humidity or the droplets which are generally found in the immediate vicinity of the high speed press rolls in the machines. paper which also tend to settle on the partitions 22b on the upward rotating side of the grooved cylinder 22, and this water on the partitions 22b is then removed by a conventional scraper, preferably by simply having

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 the shape of a blade scraper 30, which at high speeds effectively rejects water droplets from the surface of the cylinder, as shown in Figure 6, against the third part 25c of the trough which flows into the lower part 25b thereof.

   The blade scraper 30 here forms a scraper right up against the inlet side of the clamping zone N-3 and allows the partitions to be dried. Preferably the scraper 30 acts in cooperation with the partitions 22b within what constitutes at least the last 120, and preferably the last 90 of the path of the grooved cylinder 22 approaching the clamping zone N-3, so that the partitions 22b come out dry at the immediate entrance to the clamping zone N-3, If a few water droplets are carried by the scraper 30 from the partitions 22b and go to the bottom of the grooves 22c, it has been found that the particular function of the grooved cylinder 22 is not significantly altered,

   while if moisture remains on the partitions 22b this makes a considerable difference to the operation of the grooved cylinder 22, for reasons which will be described in detail later.



   Theory and advantages of the inventions shown in Figure 1 and Figure 6.



   As indicated above, certain aspects of the embodiment of the present invention shown in FIG. 6 apprt important and remarkable improvements to the embodiment according to FIG. 1; and although it is not desired to limit the invention to any particular theory, it is believed that certain theoretical considerations will explain the superiority of the embodiment of Figure 6 over that of

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 Figure 1, as well as the superiority of the embodiments shown in both Figures 1 and 6 over the prior art.



   The use of grooved cylinders for the paper pressing technique has been considered for several generations and has been rejected. For example in 1915, U.S. Patent No. 1,123,388 of January 5, 1915 was issued to Schanning, it related to a grooved press cylinder with which it was claimed to replace the felt-covered cylinders, and it disclosed grooves having a shape which according to Schanning had to retain water by capillary effect. Already in 1905, Fletcher (US Patent No. 800,845 of January 30, 1904) proposed a grooved cylinder made with some parts in the form of segments.

   During the 1920s, Goodfellow (U.S. Patent No. 1,369,365 of February 22, 1921) proposed a press cylinder having circumferential grooves as well as axial grooves which interrupted the circumferential continuity of the partitions, this cylinder was covered with felt; and Wagner obtained U.S. Patent No. 1,483,562 dated February 12, 1924 relating to grooved rolls used with two press felts co-operating with certain suction mechanisms outside the press rolls. US Patent No. 1,321,956 of November 18, 1919 to Wagner referred to grooved cylinders in a coating mechanism.

   U.S. Patent No. 1,520,489 of December 23, 1924 to Wagner relates to a cylinder having a grooved liner. U.S. Patent No. 1,517,036 of November 25, 1924 to

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 Wagner's name refers to a pair of press rollers intended to compress a moving web of paper with their bare surfaces unprotected, one such roll having grooves on its surface, "
More recently in 1958, however, Wagner obtained a United States Patent No.

   2,858,747 of November 4, 1958 which referred to grooved press rolls operating with a suction apparatus mounted outside the cylinder body, but with these exceptions in the art, it has been found that almost the entire press industry Papermaking turned its attention to the perforated cylinders, the suction cylinders, for removing water, in a squeeze-on press, once this structure was discovered and introduced into industry.

   In fact, for the last thirty or forty years, the perforated type suction cylinder has been used predominantly and in practice exclusively in the papermaking industry, to remove water in n Any large quantities of wet paper webs in papermaking machine press assemblies.



   As shown here in figure 2, in the wiping area N-4 of the suction press, the cylinder body 31 is perforated, that is, it is closed with a large number of holes 32 , 32 of large dimensions (i.e. having at least
6.35 mm in diameter and generally comprising inlets 32a flared at the periphery, of larger dimensions) which are drilled completely through the body 21 of the cylinder (the latter having at least a thickness of 25.4 mm), to ensure the

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      communication with the suction strainer G which extends over the entire width of the wall 31 of the cylinder inside, in
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 'j] b opposite the spin zone N-4.

   At the wiping zone N-4 of the -,: suction press, a press felt 33 is interposed between the strip W-2 and the perforated wall 31 of the suction cylinder, (mainly as a protective layer, permeable to l (water, strip W-2), and the water which is squeezed from strip W-2 completely passes through the felt 33 and goes into the holes 32-32, of the perforated wall 31. Part of the water continues and goes into the strainer G, part of it is usually retained in the holes 32-32 on the outlet side of the spin zone N-4, where the pressure below the atmospheric pressure prevailing in the strainer G tends to oppose the centrifugal force which pushes the water droplets outside the holes 32,32 and against the felt 33 which is subjected to atmospheric pressure.

   The felt 33 can thus remain in contact with the strip W-2 on this exit side of the spinning zone N-4 without the strip W-2 being wetted again in a significant way (by the water which is projected onto the felt 33 through the holes 32,32 of the suction cylinder).



  In addition, troughs (not shown) are placed in a conventional manner between the felt 33 and the wall 31 of the perforated cylinder, immediately on the outlet side of the strainer G to catch droplets escaping from the holes 32, 32 of the suction cylinder, especially after these holes have passed the limit (i.e. the outlet seal, not shown), of the internal suction strainer G serves that there is no longer any pressure difference to maintain the droplets in the holes 32,32. The outgoing felt 31 must be guided to avoid

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 this trough and this often results in the need to guide the felt with or against the web on the exit side of the spin zone N-4.

   The perforated suction cylinder, with its suction strainer, and with or without the trough, thus serves to carry almost all the water expressed from the belt to the spin zone.



   Despite the excellent results obtained with perforated suction rolls for a number of uses in papermaking, it must be recognized that these rolls and their auxiliary equipment are expensive to manufacture. The suction strainer placed inside, almost completely prevents the use of conventional "anti-deflection" cylinder structures allowing greater flexibility and giving greater uniformity to the pressure setting in the clamping area. .

   In addition, the large dimensions of the inlets 32 of the perforations, acting with the pressure difference produced by the suction strainer against the unsupported portions of the felt 33 in front of these perforations 32, tend to produce "shadow marks. "on the tape, in some cases.



   It is only recently, after many years of industrial use of perforated perforated cylinders, that what is known as a "side press" type structure has been developed which does not require the use of. perforated suction cylinders, for the belt press. In the compartmentalized press, the felt alone is cleaned, freed from water and put into condition in a separate press spin zone, then introduced with the bandeumide into what is called

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 a * band clamping region which is formed between rolls having walls without perforations (unlike the walls of perforated suction rolls).

   As shown in Fig. 3, ordinarily the water load in such an N-5 band clamping area is such that at least one of the press rolls 35,35a has on the surface of the recesses 36 which temporarily take charge of the pressure. Water entering the N-5 band clamping area to prevent crushing of the W-3 band carried by the felt 37.

   As shown in Figure 3, a preferred form of such recesses 36 is obtained by giving a press cylinder 35 a rubber top which contains a multitude of relatively fine blind holes (i.e. having a diameter of d. 'about 1.5 to 6 mm or even less as in the case of U.S. Patent No. 3,023,805 supra) and in the case of most W-3 tapes and conventional felts, these holes Fine 36,36 almost completely avoid or eliminate the "shadow marks" characteristic of some perforated suction cylinders. In the compartmentalized press, the principle of water removal is quite different.

   The water is not carried away from the wiping zone N-4 by the wall 31 of the suction cylinder but instead, the water squeezed from the strip W-3 into the felt 37 is carried away from strip 'W-3 roughly all the way through felt 37 on the exit side of clamp area N-5.

   The excess water at the N-5 clamping area, which is entrained in the blind perforations 36,36 and which removes the water load from the N-5 clamping area, usually contains a certain amount of air at the bottom of these blind perforations 36, 36 and this, cooperating with the capacity of the felt to absorb

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 of water as it expands on the outlet side of the zone, clamping N-5, results in a significant amount of water being removed from the system through the felt 37 which is then passed through , as previously mentioned, through a press for felt alone where it is stripped of the desired amount of water, in a separate press wringing zone.

   The principle of removing water from an N-5 band press clamping area of the compartmentalized press also features a relatively good balance of forces in the clamping area itself, where the W- band 3 is compressed so that it is freed of its water but where it is pressed against a felt 37 which is held over a large area of flats of partitions 36a between the inlets of the multiple perforations 36,36 and these perforations 36, 36 fill with water under considerable pressure (especially when air is trapped at the bottom of blind holes 36,36)

   so that overhanging or unsupported felt areas at clamp area N-5 and which correspond to perforation openings up to 3 or 6 mm in diameter are actually very well supported from below and usually show little sign of lack of support for these felt areas on the resulting compressed web W-3 (i.e. little, if any, signs in the form of "shadow marks").

   In addition, the unperforated walls 35,35a which effectively pierce the band clamping area N-5 are so constructed that they easily lend themselves to being supported by various anti-deflection devices, so that the band press N-5 has important advantages of flexibility in adjusting the pressure at the clamping area and in the

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 maintenance of uniform loads in the axial clamping zone.



   . The present invention, however, as shown in the embodiments of Figures 4, 4A and 4B, as well as for its improvements shown in Figures 5A, 5B and 8 is based on another different basic principle. , for water removal, in press clamping areas.

   First, the present invention presents a unique improvement in the compartmentalized press assembly (fig. 1) by using a grooved cylinder in place of the cylinder 35-described in connection with FIG. 3 (or, as will be explained further into the dewatering zone for felt alone) so as to obtain either a number of marked advantages over the compartmentalized strip press structure which has just been described (at the expense of certain other advantages), or to obtain all the advantages of the compartmentalized press which has just been described, with a certain number of additional advantages.



   One of the essential concepts of the present invention involves the use of a grooved cylinder with flats of partitions 13b and 22b (of the series of figure 4 and figure 5) which are roughly continuous around its circumference, so that the flats of the partitions have continuous, cylindrical working surfaces of which the outside or the outer periphery is smooth, and which come into contact with the strip or the felt 11, 23 and which support the latter. Circumferentially discontinuous bulkhead flats are almost impossible to clean during cylinder rotation.

   Also an essential idea of this first concept is that the use of such

 <Desc / Clms Page number 25>

 flats of partitions having an axial dimension 17, 27 very narrow between alternating grooves 13c, 22a which also have a small axial dimension 16, 28, but which are connected (at the periphery) to the ambient atmosphere so that the water expressed at the press clamping zone Nl, N-2 and N-3 does not experience resistance in this respect, to flow through the material of the web or felt, axially as well as radially and go in these grooves entries connected to. atmosphere (which are large enough to easily receive pressurized water).

   The grooves are of sufficient size to enable them to receive the water load at the press clamping area, while remaining connected to the ambient atmosphere and this in such a way that they do not exhibit resistance to water. The flow of water in the grooves, mainly as a result of the depth of the groove, which is formed to increase the axial dimension 16,26 of the groove to enable it to receive greater water loads. The depth of the grooves 18,28 in most use of paper machines must thus be considerably greater than the opening 16,26 of the groove at the periphery of the cylinder, so that the very essential function of communi- cation with the atmosphere is spared.

   In practical embodiments of the present invention the ratio of the depth 18.28 of the groove, to the axial dimension 16.26 thereof at the periphery of the cylinder is preferably at least 2. / 1, approximately, and may be up to approximately 10/1 or more depending on additional practical considerations such as cylinder strength, ease of cutting grooves, etc.

 <Desc / Clms Page number 26>

 



   In addition, it has been found important to ensure that the groove can easily receive the water load, by the fact that it has side walls 13c-1, 130-2, 1 or 22c-l, 22c-2 which (being radially aligned) are axially spaced from each other, by at least the width of the entrance to the groove 13,26 for at least an initial groove depth of approximately equal to the axial dimension 16,26 of the entry of the groove (at least 1.27 mm and preferably 3 mm) and preferably over the entire radial dimension of the groove 18,28.

   This concept would make it possible to give the interior of the groove axial dimensions greater than those of the axial dimensions.
16,26 of the inlet, if the formation of the latter was practical and did not decrease the resistance of the cylinder or interfere with other maintenance considerations such as its cleaning, but this concept would prohibit the use of little grooves. deep bevels which would be intended to oppose the entry of water (and / or their communication with the atmosphere) but which would not prevent an extremely slow inclination between the walls of relatively deep grooves, such as the walls would be approximately parallel in order to allow their operation in the region of the entrances of the grooves.



   In addition to the possibility that the grooves 13c and 22c have to be connected to the ambient atmosphere in the press clamping area and thus easily receive water, it has been found that an even more important consideration was part of this concept, and this consideration involves the use of a minimum axial dimension 17.27 for the flats of smooth cylindrical walls on the ridges between the grooves. As

 <Desc / Clms Page number 27>

 shown in Figure SB, the maximum axial distance that the water flow through the felt 23 (in compressed form) is approximately the distance between the midpoint M of the wall flat 22b and the edge of the adjacent groove 22c.

   This midpoint M is in a radial plane cutting in two equal parts the individual edge and the wall flat 22b and the axial distance
27-1 / 2 to the groove is approximately half of the wall flat 27.



   The liquid itself, in any medium such as water in a strip-type medium, exhibited by the felt 23, exhibits resistance to flow under any circumstance, and in the compressed felt 23, which has a dimension in the range from 1.6mm to 3.18mm, the water resistance is large enough that it is necessary to be very careful in delimiting the dimension 27- to maintain maximum efficiency in removing water from the clamping area.

   From this point of view the axial dimension of the wall plate 17,27 should be about 25% at 2005 of the radial thickness 23a of the compressed felt to obtain the best results for the water flow 'axially, laterally to. through the compressed felt and into the grooves 22c on each side of each wall plate 22b. Preferably the ratio of the axial dimensions of the flats of the partitions
17.27 to the thickness 23a of the compressed felt is found e.itre 1/2 and 1/1.



   Another important consideration in the practice of the present invention with respect to the axial dimension of the grooves 16,26, at the entrance to them, is that of "shadow marks" in the case of the webs passing through. the clamping area.



   We realize that the "shadow marks" in themselves are not important when it comes to a press for ...

 <Desc / Clms Page number 28>

 felt alone, nor is an important factor in the case of certain types of inferior webs or in the case of certain paper machines in which extremely heavy felts are used. In such cases, it might be possible to use grooves having large axial dimensions 16, 26 of up to about 3 mm, above which the felt would tend to enter the grooves by a significant amount, this which would produce unnecessary additional wear of the felt, possible clogging of the water flow and / or the communication to the atmosphere, etc.

   Further study of this issue has shown, however, that 16.26 axial dimensions of grooves, which are much greater than about 0.89mm tend to produce unwanted marking on some tapes and / or allow the felt of most. of the weights used to temporarily enter the grooves in a disadvantageous manner, under the change of the clamping area, which increases the wear of the felt and it was found that a groove dimension, at most 089 mm a very important limited point for most pressing operations. The axial dimension of the grooves 16.26, the minimum practicality which allows water to be received and performs the essential function of communication with the atmosphere, is in the vicinity of about 0.127 mm.



  As previously indicated, the best results are obtained using an axial groove dimension of approximately 0.635 mm.



   The foregoing concept of communication with the atmosphere which is essential for the practice of the present invention is based on certain fundamental theories.

 <Desc / Clms Page number 29>

 which involve the design of grooves having the best qualities to receive water and to connect to the atmosphere the pressure of the clamping zone to which is added the design of flat surfaces of partitions having superior qualities to produce axial or transverse flow of water through the compressed felt to send it into the grooves with minimal discomfort and minimal pressure gradients, across the surfaces of the flats of the partitions.

   In the case of a band clamping area such that the pressure gradient is a function of the pressure of the fluid that exists at the interface between the felt and the band, it is important for the pressing to connect to the atmosphere this fluid pressure in the felt, or to relax it to as low a level as possible, which is best obtained by uncovering the "back" of the felt so that it is sufficient that the water only passes through the thickness compressed felt to join the ambient atmosphere that exists in the grooves.



   Another aspect of the present invention which has been found to be very important is that of reducing the flow of water through the felt compressed in these grooves, obtained by preparing the surfaces of the flats of the partitions. on the entry side of the clamping area. From this point of view, reference should be made to FIG. 7A, which shows in a view directed transversely, the surfaces 22b of the flats of the outer peripheral partition wall alternating between the grooves 22c but carrying water droplets D (in the form of 'a meniscus) which adhere to the flats of the partitions 22b.

   We realize that in the operation of paper machines which include

 <Desc / Clms Page number 30>

 pressing parts, a significant amount of water is handled and this water comprises droplets in the form of mist in the air as well as water which actually remains as droplets on the surface of the cylinder , so that the surface of the cylinder usually tends to remain continually wetted.

   It should be realized, however, that any droplet carried by a wall flat 22b in the nip zone N-3 (or N-1, N-2) is first immediately compressed in the body of the felt and must then travel the axial dimension indicated above, through the compressed felt and go into the grooves in communication with the atmosphere on each side of the partition 22b. This phenomenon is avoided according to the practice of the present invention by means of a very simple process.

   In Fig. 1, the scraper in the form of an air apparatus blows on these droplets and pushes them from the flats of the partitions to dry them on the inlet side of the clamping area N-1, N -2 (within an arc of at least 120 on the entry side the clamping areas on grooved press rolls, and preferably within roughly the last quadrant or
90 of rotation of the grooved cylinder which approaches the clamping area), The press assembly 20 of FIG. 6 shows the use.

   sation of a simpler, robust, inexpensive and advantageous scraping device to obtain the desired result with greater ease and without the need to atomize or blow the droplets into the ambient atmosphere so that they are redeposit on other elements in operation. This is essentially achieved by the use of the blade scraper 30 which is a

 <Desc / Clms Page number 31>

 classic blade scraper in all other respects and which has this advantage.

   He went up, however Immediately to the side. entry of the clamping zone N-3 so as to be sure that the flats of partitions 22b are dry when they approach the clamping zone N-3, From this point of view, it can be seen that the scraper
 EMI31.1
 30 which presents what aonsitue a c4nti surface, naked ac.à3.eamen. pushed against (or all against) the rotating periphery of the cylinder, has a structure considerably simplified in that it is not complicated by devices intended to reach the interior of the grooves 22c.

   An important aspect of the present invention is that devices for reaching the interior of the grooves 22c at this particular location are not essential, as the grooves
22 are provided with sufficient depth 28 to allow the return of at least a small quantity of water in the clamping zone N-3, in the grooves, without hindering the overall operation of the press 20 The important point to consider here is that unnecessary additional water flow axially through the compressed felt is avoided by introducing water onto the surfaces of the wall flats 22b at the clamping area.
N-3,

   
Ericore another very important point to consider is the fact that on the press cylinder 22 which constitutes the preferred embodiment of the invention the grooves 22c and the circumferential and alternating ridges 22b ,, on-1; the volume of continuous spirals, which differs from the grooves and ridges exactly aligned around the circumference and exactly spaced axially around the entire periphery of the cylinder.

   This last structure

 <Desc / Clms Page number 32>

 of cylinder can be used in the practice of the present invention giving a number of advantageous results and the spiral grooving is clearly superior from the point of view of manufacture and use as will be demonstrated. far, there are machine tools for cutting the desired grooves (in the form of spiral threads) on the surface of such cylinders with much more ease and precision than can be done in the practical operation of workshop 'which peddles the cutting of exactly circumferential grooves.



     In addition, the ranger 30 has a continuous axial surface which is able to cooperate only with a spiral groove to rid the flats of the partitions of their water, while neither any apparatus which needs to reach the interior of the spiral groove. could not be maintained at a fixed point, and have an operation as simple as that of the apparatus 30.



     Referring now to Figure 7, it will be seen that the sweeper 29 also has a unique arrangement for generally removing water from grooved cylinders, and particularly for removing water from cylinders having grooved grooves. spiral of the type just described.

   The sweeper 29 does not enter the grooves 22c, but performs its function of pumping water from the grooves 22c by means of its new and simple structure, and performs this function on the inlet side of the scraper 30, so that it does not take water in the ures 22c to put it on the surfaces of the flats of the partitions 22b so that the water is carried away in
 EMI32.1
 the H-3 clamping xone on these partitions.

   Essentially, the sweeper 29 has an axially continuous surface portion 29a

 <Desc / Clms Page number 33>

   which extends from a close vicinity of the cylinder surface 22 (and which is actually pushed against this surface) on peripheral surface portions or on wall flats 22b thereof, this surface 29a moving apart gradually from said surface of the cylinder or surfaces of the flats of partitions 22b (from the contact region L-1) so as to form with the periphery of the cylinder, which turns away,

   two gradually diverging surfaces used to pump liquid out of grooves 22c as the surface of the cylinder passes the sweeper
29. As shown in Fig. 7, the combination of centrifugal force, gravity and vacuum produced on underside 29c of sheet 29a of sweeper 29 results in:. withdrawing the water (indicated schematically at 29d) to bring it out of the grooves 22c and send it in the general direction of the underside 29c of the sheet 29a.

   This is, of course, achieved primarily by the purge air A-7 which rushes (as shown schematically) along the peripheral surface of the grooves 22c to fill the partial vacuum produced by this pumping effect. It will be appreciated that the structure of the scanning apparatus thus represented is remarkable for its simplicity, for its ease of assembly, installation, operation, maintenance, etc., and moreover for its function at the same time. 'With regard to grooves 22c having a general spiral shape,

   because the device rids them of their water without having to reach the interior of the grooves and consequently without proper axial displacement necessary for a sweeping device
29 which should run continuously through the spiral grooves.

   It was found that the basic and simple structures

 <Desc / Clms Page number 34>

   of the sweeper 29 and the scraper 30 cooperate in a highly efficient manner with the press assembly 20 to give the best working results. The scraper 30 itself has the unique function of improving the efficiency of the press at the area. clamp N-3, and 1 sweeper 29 that of drawing water from the grooves 22c by a very simple structure and phenomenon, These two devices
 EMI34.1
 29 and 30 #.

   individually and in cQm.bimd..son, are very helpful to work with the spiral grooved press cylinder in that they improve the basic operation thereof.



   In addition to the previously mentioned advantages of spiral grooving on the cylinder 22, which involves the least expensive size and the most safe from mishandling of these cylinders on a lathe, there is a special cooperation between the surfaces of the flats. 22b spiral partitions and the scraper
30 and / or the sweeper 29 which causes no damage to the felt 23. around the clamping zone N-3 the spiral grooves 22c and the ridges 22b momentarily come into contact with the felt 23 under compression (which moves exactly circumferentially ).

   and during this momentary contact the course of the grooves 22c and the ridges 22b is approximately (and practically) aligned circumferentially, and their axial course is so small that no damage results to the felt. The ridges 22b fill a exactly opposite function vis-à-vis the scraper 30 and / or the sweeper 29.

   These devices remain in a fixed position and come into contact with the ridges 22b of, so that the spiral component of their displacement (axial movement) has the net effect of continuously cleaning, sweeping and / able to scrape the contacting surfaces of the machine. scraper 30 and / or sweeper 29,

 <Desc / Clms Page number 35>

 
In many respects, the foregoing structures of grooved cylinders 13 and 22 are particularly useful even when the inlets of grooves 16, 26 may have larger dimensions (eg up to 2.5mm or more at the area of spin N-2 for felt only), even when they go so far as to produce certain marks at one of the tightening or spin zones N-2 or N-3.

   In the preferred embodiment, these marks are avoided by using very narrow groove openings 16,26, having an axial dimension of less than about 0.89 mm (and preferably having about 0.79 mm). It has been found that this maximum axial dimension is significantly greater when used in the practice of the present invention. It has been found that axial dimensions much larger than this do not give a much better result for any ordinary use of the present cylinder, while larger axial dimensions tend to produce marks on the web, in the process. most cases.

   In manufacturing and selling grooved press rolls for the uses contemplated in the practice of the present invention, it has thus been found to be particularly advantageous to maintain the axial dimensions of the grooves at 0.89 mm or less. Among other things, this has the advantage of avoiding the need to give special instructions on the use in the workshop of grooved rolls, since such grooved rolls can be used in presses for felt alone, as well as presses for felt-only presses. strips, using felt of different weights and paper strips of different qualities and types.

 <Desc / Clms Page number 36>

      



   Within the limits stated above, it is understood that certain relationships between the grooves and ridges in the felt-covered press cylinder (eg cylinder 15 of Fig. 1) of a web press in a compartmentalized press may not be so delicate because the felt 11 is intended to take away the greater part of the water expressed from the strip Wl and that rewetting of the strip is avoided, in FIG. 1, by guiding devices separating the strip and the felt at the immediate exit of the clamping zone Nl.

   The ratio of the axial dimension 16 of the groove to the axial dimension of the partition 17 is at least about 1/1 and preferably within the limits of 1/1 to 1/3 (i.e. say 0.79mm to 1.59mm and up to 2.38mm) to remove water from the strip satisfactorily, which assumes an open area of between 50% and about 25%.



   Extensive research has revealed, however, that significantly better results are obtained using a considerably smaller open area, not exceeding 25% (e.g. less than 0.79mm for the groove with 2.38mm for the bulkhead. ). This constitutes an important difference between the cylinders 13 and 22, without taking into account that an essential aspect of the present invention is the ease of the grooves to receive large amounts of water. The reasons why this upper limit of open area of about 25% (and preferably
20% with 0.635 mm grooves and 2.54 mm partitions, in fig. 5B) is that it has been found that this relatively small open area does not appreciably prevent water removal of the tape (by the felt)

   with the clamping zone pressures used,

 <Desc / Clms Page number 37>

 while it makes it possible to fulfill what is perhaps the second most important function, that which gives great flexibility to the grooved cylinders according to the invention, This function consists in reducing the possibilities of rewetting the felt at the exit from clamping zone N-3.

   While this feature greatly helps to remove water in a (compartmentalised) web press clamping area, and reduces or weakens the water load carried by the felt from the web into the compartmentalized press, it is capable of actually removing just about all the water (through the grooved cylinder in a tape press clamping area) and allows the grooved cylinder to replace a conventional suction cylinder in a tape press, as shown in Figure 6 , particularly on a second or third press in a set of presses (eg the set shown in Fig. 13).



   In Figure 6, it will be noted that the felt 23 is roughly aligned on a tangent plane TT to the clamping area (or preferably slightly above) on both the inlet 23a and outlet 23b sides, by means of the upper surfaces of the guide rollers 24a, 24b which are placed on the side of the tangent plane TT opposite to the cylinder 22 so that the felt 23 has only minimal contact with the cylinder 22 (only at the area N-3), that some of these parts do not tend to be trapped in the grooves 22c, that it does not tend to obstruct the ambient pressure on the entry and exit sides of the clamping area N -3, that it only undergoes a minimum of wear by its contact with the edges of the partitions (for example in 22b-1 in fig.SB,

     edges which are preferably sharp to achieve the other benefits

 <Desc / Clms Page number 38>

 described here), that it undergoes only a minimum of wear as a result of the axial displacement of the spiral partitions 22b at the clamping zone N-3, that it allows to properly position the trough 25, and . that it does not withdraw or receive a minimum of water from the grooves 22c on the outlet side 23b of the clamping zone N-3.

   The grooves 22c, of course, oppose the expulsion of water by centrifugal force (particularly more on the side of cylinder 22 which turns upwards or on its top, than on the side which turns downwards. when gravity is added to the centrifugal force) but what is expelled (in D-3) is almost entirely thrown against the upper part of the trough 25a immediately at the exit of the clamping zone N-3 between the cylinder 22 and the felt 23b.



   Although the path of the felt 23b on the exit side is important for many uses, the open area is still very important because some rewetting of the felt 23b on the exit side of the clamping zone N-3 is roughly instantaneous because the felt expands when released from the pressure of the clamping area and is then very absorbent, At this point the "path" of the water is reversed outside the grooves 22c to go to the most distant parts of the absorbent felt 23, which would be along the center line or, plane M (fig.SB) above each partition 22.

   It has been found that this reversal of the water path in a preferred construction of cylinder 22 can be reduced by using a ratio of the width of groove 26 to the width of a partition 27 having a practical minimum value of. 1/3 to a practical maximum of about 1/20 above which removal of water from the web and / or felt is unduly hampered in the press clamping area N-3 (and using preferably an open area ranging from about 25%

 <Desc / Clms Page number 39>

 around 10%, in practice).



   In particular, when using the combination of the previous ratios (grooves to partitions) of 1/3 to 1/20, partitions having approximately a width ranging from 1.27 mm to 3.81 mm, grooves having With a width ranging from 0.25 mm to 0.89 mm, a remarkably flexible press cylinder is obtained which can be used in any press assembly (eg the one shown in Figure 13). Best results have been obtained using approximately the exact dimensions given for cylinder 22.

   Groove depths 28 at least sufficient to carry the water load are used and preferably the preceding combination includes grooves which have depths (approximately radial) of at least two to ten times their width and equal to less than the width of the partition, and having at least 0.25 mm, with a maximum groove depth limited mainly by practical considerations, although angled or rounded groove bottoms not exceeding a depth of about 6 mm are generally superior to other structures when it comes to combining strength, cleaning and ease of manufacture.



   Within the limits of the previous parameters, open areas of 25%, 20% and 15% (successively) can be used on the first, second and third web presses of a machine, each time removing a little less of water to each press.

   Using the press cylinder 22 hereof. invention in a compartmentalized press (for example at the positions of the cylinders 13 and 15 in fig. 1), an adjustment is obtained

 <Desc / Clms Page number 40>

 of the condition of the strip which enters the strip press clamping zone and the guiding devices 11a, 11b, 11c, 11d can advantageously be used to keep the felt approximately tangent to the zones N-1, N -2, with additional guiding devices, 19,19 to separate the strip W-1 from the felt 11 immediately at the entrance and at the exit of the clamping zone N-1 to better act on the water transfer from tape W-1 to felt 11, and vice versa,
Further embodiments of the present invention,

   - Referring now to Figure 8, it can be seen that this embodiment of the present invention, generally indicated by the reference 40, represents a band press in which the press clamping area N-8 is formed between a grooved upper cylinder 42 and a lower liana cylinder 41, which is in contact with the strip W8 moving on the underside of the felt 43. The elements of Figure 8 which correspond to those of Figure 6 have been designated by the same reference numbers in the 40 series.

   It can be seen that the smooth bottom cylinder 41 may tend to carry a small amount of water from the strip W-8 and this cylinder 41 is cleaned by a scraper 41 on the inlet side of the spinning zone N-8, the scraper discharging water and the like into a trough 41b. Grooved cylinder 42 has much the same construction as cylinder 22 previously described except that preferably the width of the grooves is only 3.81mm for a 15% open area and press 40 is used as the third. press to remove a relatively insignificant amount of water. The reduced open area decreases rewetting of the felt 43 on the exit tee of the spin zone N-8.

   Part 45a of the trough on the exit side of the N-8 dewatering area

 <Desc / Clms Page number 41>

 extends between the felt 43 and the surface of the cylinder 42 approximately immediately at the exit of this zone N-8 and it collects some water droplets as shown schematically.



   On the side of the grooved cylinder 42 which rotates downwards, a scraper 49 having roughly the structure of the scraper 29 and a scraper 50 which has approximately the structure of the scraper 30 are mounted to cooperate together, as well as with the part 45c of a trough. Trough 45c carries scraper 50 as close to the inlet side of spin zone N-8 as is practical to allow trough 45c to collect and draw water swept from partitions 42b of cylinder 42 by scraper 50.



   Referring now to Figure 9, it can be seen that it represents a compartmentalized press generally indicated by the reference 60, with a band clamping zone N-9 between a smooth upper cylinder 61 and a grooved lower cylinder 62 in which the elements are arranged roughly as shown and described in connection with Fig. 6, except that the web W-9 is guided by rollers 71a and 71b at the entrance and exit of the zone of tightening N-9 so that the strip W-2 is in contact with the felt 63 only about only in this zone N-9 (the strip W-9 tending to adhere to the side of the upper cylinder 61 which turns upwards (granite) at the exit of, the nip zone N-9, which helps to separate the web W-9 and the felt 63 immediately at the exit of the nip zone N-9,

   even if the felt F-3 is mounted on guide rollers 64and 64b which keep it just a little above the tangent plane passing through the clamping area N-9).

 <Desc / Clms Page number 42>

 



  The removal of the water and the cleaning of the groove cylinder 62 are carried out by elements whose structure and function correspond to those already described for figure 6 and which are designated by corresponding reference numerals in the series of 60, the scraper being designated by 70.



     In Fig. 9 there is also a felt-only wiping zone generally indicated at N-9A which is formed by a smooth press cylinder 73 placed inside the loop formed by the felt 63 and by a grooved press cylinder 72, which has the same structure as the grooved press cylinder 62 and the grooved press cylinder 22 previously described, and which is placed outside the loop formed by the felt 63 to act on the outer peripheral "working" surface 63a of the felt 63 to be cleaned, repaired and freed of its water.

   The grooved cylinder 72 is provided with a trough 75 for mounting a sweeper 79 having the same structure and function as the previously described sweepers 29 and 69 as well as a scraper 80 having approximately the same structure and function as the scraper 50 of the machine. Figure 8, which also acts with the turning side down of a grooved cylinder. The scraper 80 is placed against the inlet side of the spin zone N-9A for felt only, and. in order to be more efficient at removing water from this area N-9A, it is mounted so as to cooperate with the trough 75 to trap the water removed in this way to cooperate with the trough 75 to trap the water removed in this way and water which is thrown from the periphery of cylinder 72 by the action of sweeper 79.

   The felt 63 is mounted so that it moves approximately beyond an indicated tangent plane

 <Desc / Clms Page number 43>

 generally in T-9A, in order to have minimum contact with the surface of the grooved cylinder 72, and to separate quickly at the exit of the spinning zone N-9A and to be able to place d Advantageously, the leading edge 75a of the trough 75 immediately at the exit of the dewatering zone N-9A for felt alone between the felt 63 and the surface of the grooved cylinder 72.



  The compartmentalized press 60 is used to obtain an extremely efficient action on the movement of water in the two areas of clamping N-9 and spinning N-9A.



   Referring now to Figure 10, it can be seen that the embodiment of the present invention shown in Figure 10 includes a heat press 100 which receives a heated web W-10 from the last dryer 101, which it passes over a roll. guide 102 and goes into the clamping zone N-10, from which the hot strip W-10 passes over a guide roller 103 separating the strip W-10 and the press felt 104 immediately upon exiting the zone N-10 clamp, by passing the W-10 web over the first dryer 105 of the next drying section, The heat press 100 has a web press clamping area formed by a smooth upper cylinder 106 and a cylinder lower press 107 which has roughly the same structure as the cylinder 22 described above,

   with a trough 108 which corresponds to the trough 25, a sweeper 109 which corresponds to the sweeper 29 and a scraper 110 which corresponds to the scraper 30, all of which have been described in more detail with regard to the cylinder 22. The cylinder 107 however has a top 107a of stainless steel, which is grooved as described in connection with grooves 22c and flats of partitions 22b of cylinder 22;

   but it is advantageous to use a steel structure 107a

 <Desc / Clms Page number 44>

   in the N-10 hot press clamping area. The felt 104 is mounted on felt guide rollers IIIa-IIIb, IIle and III plus a tensioning roller IIle, in a conventional manner, and the zone of The N-10A felt-only spinner is between a smooth press cylinder 112 placed inside the loop of the felt 104 and a grooved press cylinder 113 placed outside the loop of the felt 104.

   The . Groove press cylinder 113 is provided with an assembly trough 114 whose function is comparable to trough 108, with a sweeper 115 and a scraper 116 which correspond to the sweeper 109 and the scraper 110, except for the fact that the elements are reversed, the scraper 116 being mounted on the upward rotating side of the cylinder 113 for cleaning the latter immediately in front of the entrance to the spin zone N-10A.



  On the press assembly shown in FIG. 10, a control box 117 is shown schematically, it is intended to receive a signal from a conventional humidity detector device (beta gauge). A shower 119 controlled by a control valve 120 is placed inside the loop of the felt 104 to give it the desired quantity of water on the inlet side of the spin zone N-10A for felt alone. The control valve 120 may be manually operated, or it may be, and preferably is, operated through the control panel 117 either automatically or by an operator who can read the moisture content on a device in the machine. control panel 117.

   In addition, it is seen that conventional fluid actuated clamping pressure control devices indicated by the

 <Desc / Clms Page number 45>

 Double headed booms at 122 and 123 on the lower press rolls 107 and 113 respectively are provided with usual controls which are connected to the control panel 117.

   It is thus seen that the grooved cylinders 107 and 113 can be readily used in compartmentalized, pressure-controlled press assemblies in which the pressure at the N-10A felt-only wringing zone is controlled such that it is at least as great as the pressure in the band clamping zone N-10 and preferably slightly higher, to allow the felt 104 which passes through it to be cleaned, repaired and free of water from it, and the overall operation of the press assembly 100 can be performed automatically using the control box 117 in which the elements 122,123 and / or 120 can be controlled in response to signals received by the control box 117 from the detector apparatus humidity 118,

   or they can be controlled by the operator who sends conventional pneumatic signals to the control box 117 according to his own observations and the reading of the device indicating: the moisture content.



   Another feature of the present invention involves the use of anti-deflection mounting devices, which are shown here schematically as part of the pneumatic charging device 122 and 123 of the cylinders 107 and 113. It will be appreciated that the mounting devices Cylinder deflection protection is now known in the art and is shown in patents such as US Patents Nos.



  2.648.122 of August 11, 1953, no. 2.651.103 of September 8, 1953, and no. 2,651,241 of September 8, 1953. Moreover, in the French patent application of April 23, 1963 in the name of the same applicant

 <Desc / Clms Page number 46>

 and titled "Anti-deflection cylinder, in particular for papermaking", are described preferred embodiments of anti-deflection mounting devices - for such rolls, and anti-deflection devices of the type described therein. requests are used for editing. cylinders 107 and 113, as well as for all other cylinders shown below, with the schematic symbol of a two-headed arrow for control of clamping pressure or load.

   The embodiment described here is that which comprises mounting on rubber parts clamped on a through shaft, shown in the aforementioned French patent application of April 23, 1963,
A common feature of all these anti-cylinders. deviation is the fact that the cylinders have unperforated walls which are supported almost completely or largely axially inwardly from the ends of the walls by support devices placed therein , carried by a shaft allowing the body to turn.

   The term "anti-deflection cylinder" used here means a cylinder having a telle structure, which moreover cannot be used with suction cylinder bodies (because inside these is necessarily mounted the strainer),
Referring now to Figure 11, we see that the press it represents and which is indicated in a way. General by reference 120 is a compartmentalized press formed only of three cylinders 121, 122 and 123, the central cylinder 122 being a grooved cylinder having a structure approximately identical to that which has already been described for cylinder 22.

 <Desc / Clms Page number 47>

 



  As indicated on the press 120, the W-11 strip passes through the N-11 strip clamping area but only contacts the felt 124 almost only in the pressure area of the clamping area to remove the desired amount. of water from the strip W-11 and transfer the latter partly to the felt 124 and partly to the grooves of the grooved cylinder 122. The felt 124 then passes around guide rollers 124b and 124c and passes through a dewatering zone N -11A for felt only. The water is removed by the scrapers 123a and 123b which cooperate in a conventional manner with a trough 123c.



   The grooved press cylinder 122, however, performs a dual function of removing water from the felt alone in the wiping zone. N-11A from the felt alone, and this water is removed from the upward rotating side of the grooved cylinder 122 by the cooperation of a sweeper 126, a scraper 127 and a bucket 128 having the functions already described here. On the side of the grooved cylinder 122 which rotates downward, the water removed from the web at the band clamping area N-11 is removed from the cylinder in the same manner, by a sweeper 126a, a scraper 127a and a trough. 128a which operate as already described, except that their positions are reversed compared to those of elements 126, 127 and 128.



   Referring now to Figure 12, it will be seen that the elements shown there correspond largely to the elements shown in the press assembly 120 of Figure 11, and the elements which have the same structures and functions as those of figure 11 are designated on the

 <Desc / Clms Page number 48>

 figure 12 with the same reference numerals throughout the series
130. An important difference in the compartmentalized press assembly 113 is the fact that the lower press cylinder '
123 is a grooved cylinder whose structure is approximately the same as that of the central grooved cylinder 132 (which in turn is identical to that of cylinder 122 in Fig. 11).



   The lower groove cylinder 123 serves to remove a larger quantity of water from the felt 134 in the wiping zone
N-12A for, felt alone, so that a better action is obtained on the water content of the felt and this allows the strip
W-12 to move to enter and exit the clamping area
N-12 'tape press, on felt 134.

   Removal of the water in the band clamping area N-12 is carried out almost completely by the grooved press cylinder 132, which can be operated without the sweeper 136a and the scraper 137a acting on the rotating side. down, if desired, for the reason that it can transfer almost completely all the water removed from the N-12 clamping area of the web to the N-12A felt spin area alone, where it is finally transferred into the grooves of the lower cylinder 123.

   The N-12A dewatering zone of the felt alone thus has the additional function of effecting the substantially complete removal of water from the grooved cylinder 132 as well as from the felt.
134, up to the desired value, in the spin zone N-12A for felt only. The grooves on the two cylinders 132 and 133 are preferably slightly offset axially. The sweeper 133a (which is combined here with a scraper 133d cooperating with it) and the scraper 133b, as well as the trough elements 133c serve

 <Desc / Clms Page number 49>

 removing water from the grooves of the lower grooved cylinder 133 as previously described.

   Fluid actuated anti-deflection mounts, generally indicated at 139 and 139a for the upper and lower rolls 131 and 133, are also used in the compartment press 130 to control the loads at the clamping areas and. spinning, in the manner already described.



   Figure 13 schematically shows an overall assembly of presses, generally indicated by the reference numeral 200, for the purpose of showing the flexibility of the grooved rolls of the present invention. In assembly 200, the W-13 strip is removed from an FW forming wire mesh (which runs again by rotating around a roll 201) by a removal felt 202 wound around a conventional removal cylinder. suction 203, the suction zone being shown schematically at 203a. then the band W-13 passes through a first press P-1, a second press P-2 and a third press P-3, in which the clamping pressures are successively 36 kg, 54 kg and 72 kg per linear centimeter to effect the 'W-13 strip water removal.

   Each of the press rolls 222. 242 and 272 has essentially the same structure and function as the grooved press rolls 22, 42, and 72 previously described; and the grooved press cylinder 242a has a structure and function comparable to that of cylinder 242 except that it has grooves having a width of approximately 0.89 mm and an open area of approximately 25%, to accommodate the maximum water charge and operate as transfer press cylinder in the first press P-1 in cooperation

 <Desc / Clms Page number 50>

 with conventional suction cylinder 290 to transfer web W-13 to lower press felt 291.

   The removal feutra 202 then passes around conventional guide rollers as shown in the figure and enters the N-14 spinner zone for felt only of a compartmentalized press formed by an anti-deflection cylinder 293 and a suction cylinder.



  294.



   The second press P-2 has approximately the same structure as the press 20 in Figure 6 and the corresponding elements have the same references in Figure 13 in the 200 series. The web W-13 is taken at the exit of the machine. second press P-2 and pass over a web guide roller 296 and go to the clamping area N-208 of the third press P-3, which is composed of elements whose structure and function correspond roughly to those of the elements described for figure 8, and which have the same reference numerals in the 200 series.

   As in the case of the previously mentioned grooved cylinder 242a, the grooved cylinder 242 is provided with a trough 245 on which is mounted a scraper 250 right up against the inlet side of the clamping area and a sweeper 249, shown here as operating on the side of the grooved cylinder which rotates upwards, to remove water from the grooves (mainly for convenience of representation in the drawing, as the sweeper 49 in figure 8 works best on the side of the cylinder which rotates downwards ).



   The third press P-3 also differs from the press 40 of Figure 8 in that it is part of an assembly. compartmentalized press with an N-209A spin zone for felt only which roughly corresponds in function and structure "

 <Desc / Clms Page number 51>

 to the dewatering zone N-9A for felt alone (vertical) previously described in FIG. 9, and the elements shown in connection with the dewatering zone N-209A for felt alone, which roughly correspond in structure and as a function those which are associated with the previously described spin zone N-9A bear the same numbers in the 200 series.

   In addition, it is seen that the felt 243 passing through the third clamping zone N-208 is mounted on guide rollers 296a, 297b, etc., which cooperate with the paper guide rollers 296 and 297 to separate the web W -13 of the felt 243 both entering and exiting the N-208 clamping area.



   In the press assembly 20C of Fig. 13, it will be appreciated that the suction rolls 290 and 294 can both be grooved press rolls having the structure previously described for the press roll 22.



  In fact, the flexibility of the present invention is particularly appreciated in Fig. 13, since the press cylinder 22 could be used as a press cylinder in positions 242,242a, 222,272, 290 and / or 294. In addition, from such grooved press rolls, the walls of which have no perforations, and which are mounted on the anti-deflection devices described above, can be used in press assemblies with automatic or semi-automatic control or by an operator , such that the assembly 200 comprises control panels C1, C2, C3 of conventional type, able to receive one or more signals giving the moisture content and coming from humidity measuring devices (beta gauges) placed in B1 , B2 and / or B3,

   to selectively operate the various

 <Desc / Clms Page number 52>

 fluid pressure-actuated anti-deflection cylinder mounting devices, indicated by double-headed arrows and designated by FP in the drawing, The showers shown schematically at S-1 and S-2 also operate at approximately. the same way as that which has been described for the shower 119 of FIG. 10, they are likewise capable of being controlled from the control panels C1 to C3, according to the known control methods and with control apparatuses known, The different lines for the control signals are shown in dotted lines in Figure 13.

   Referring now to Figures 7B and 7C, it is seen that in a further aspect, the present invention includes a device for cleaning a spiral grooved cylinder such as cylinder 22 while it is in use. This device . ,
300 is safe and has a quite simple structure, which includes. a support element 301 which can be made of wood and on the underside
310a of which are rigidly mounted or embedded a number of spaced apart, thin, relatively short and approximately parallel guide devices in the form of metal strips 302a through
302e, Each of the strips 302a to 302e is intended to run through the adjacent grooves 22c, between the partitions 22b at the periphery of the cylinder 22.

   The outer guides 302a, 302b, 302d and
302e have a shallow (radial) dimension such that they do not reach the bottom of the grooves 22c but simply run through them to guide the element 300. The central element 302c, however, is preferably the element which performs cleaning and this element has a thickness or a radial dimension more

 <Desc / Clms Page number 53>

 large, so that it runs along the bottom of one of the grooves 22c as shown in FIG. 7B, and that it cleans the latter by traveling it. The support element 301 is also provided with a leading edge 301b which generally forms an acute angle with the backs of the guide elements 302a, etc.

   (or the general plane in which they all lie), so that the leading edge of the scraper 30 fits against this leading edge 301b and allows for relative axial displacement between the blade scraper 30 and the element. bearing 301. In this way, the spiral grooves
22c give an axial movement to the comb 300, while the cylinder 22 operates with:

  Continuous way by pushing the comb
300 against the scraper 30, The grooves 22c will of course be placed on the cylinder 22 so as to extend beyond the axial dimensions of the scraper 30 or to the full edge of the body of the cylinder 22, so that ' we can remove the comb
300 from one edge of cylinder 22 and then separate it from scraper 30 at the opposite end of cylinder 22 when comb 300 has passed the full width of cylinder 22 (transversely).

   It will be appreciated that the overall angle of the spiral of the grooves 22c is only a few degrees, so that nearly straight guides 302a, etc., will easily run through the grooves 22c although they are axially displaced by as described above, as the cleaning guide 302c removes unwanted material from the groove it traverses along its drive edge indicated at 302c-1.



   It can thus be seen that the comb 300 is an apparatus intended to clean the bodies of continuously rotating press rolls, comprising a peripheral surface

 <Desc / Clms Page number 54>

 having grooves 22c aligned circumferentially and alternating with ridges 22b also aligned, the grooves
22c forming a continuous spiral at the periphery of the cylinder
22. The comb 300 is intended to have sliding contact with the edge of the scraper 30 to move relatively axially carrying a number of parallel guides, aligned at the periphery, 302a, b, etc. ., sliding in the grooves at the periphery of the cylinder, the guide device 302c coming into contact with the bottoms of the grooves 22c.



   It can thus be seen that the comb 300 of the present invention constitutes a remarkable device, robust and immune to false operations for easily cleaning the grooved rolls. (spiral grooves) of the present invention while in operation, the apparatus can be used with any blade scraper, for example the scraper blade, 30, it can be used with a separate guide member having an edge comparable to the edge of the blade scraper, preferably on the inlet side of the scraper and preferably for a number of operations, on the side of one of the downward rotating grooved rollers, so that the comb is pushed against this device not only by a friction or drag effect of the grooved cylinder,

     but also by gravity and that it has less chance of escaping from the end of a scraper, when the operator does not observe the operation and there is a risk of falling in certain parts of the operation. the machine. An experienced operator will be able to prepare

 <Desc / Clms Page number 55>

 against such a situation, and the essential structural need for cooperation between the cylinder and the crosspiece is that the spiral grooving on the cylinder must extend transversely beyond the fixed crosspiece or scraper, where although .spiral grooves should extend to the end of the cylinder shell,

   so that we can start the comb and remove it without moving the scraper or other cross piece used to guide the comb during its axial movement.



   Referring to the grooves 22c shown in Figure 7C as being approximately vertical and aligned parallel to each other on the small portion of the cylinder surface shown in this view, it will be appreciated that the angle of the spiral or angle of these grooves 22c with the centroid axis of the cylinder body should be a relatively small angle, alpha, which can be expressed by saying that for a 20 inch press cylinder diameter (i.e. a radius of 25.4 cm) the tangent of the angle alpha should be approximately t
 EMI55.1
 The alpha tangent should be in a range of from about 0.003 to about 0.03, preferably

   
It goes without saying that the present invention is not limited to the embodiments described and shown and is capable of receiving all variants falling within its scope and within its spirit.


    

Claims (1)

ABSTRACT EMI56.1 , ">. A, Press set characterized by the following, separately or in combinations: 1 It comprises a first smooth press cylinder, a second press cylinder forming a first press clamping area with the first cylinder, a loop-shaped felt wrapped around the second cylinder and passing through the first clamping area with a wet fibrous web, a third press cylinder placed inside the felt loop, a fourth press cylinder placed outside the felt loop and forming a press spin zone for felt alone with the third cylinder, this fourth cylinder having a certain number of flat wall surfaces aligned at its periphery, intended to support the felt in the wiping zone, the grooves placed between the partitions being intended to receive the water coming from the felt at the wiping zone, and a device for sweeping the water from these grooves onto said fourth cylinder at a point remote from the wiping zone formed by the cylindrest 2 The second and fourth press rolls are provided with numerous flats of partitions aligned at their peripheries, intended to support the felt on them in the clamping zone, the grooves placed between the partitions being intended to receive water from the felt at the wiping zone, and a device for sweeping water from these grooves on said second and fourth cylinders at points remote from the clamping zones formed by each of them; 3 The set includes a moving felt forming <Desc / Clms Page number 57> a loop and a number of press rolls and is characterized in that said elements are arranged to form a first press clamping zone between press rolls provided with unperforated roll bodies intended to receive the felt with a wet strip in order to transfer the water from the strip to the felt and a second press wringing zone between rolls intended to receive the felt alone and to rid it of its water, the non-perforated roll body on which is wound the felt at the first clamping zone having part of its peripheral surface with numerous grooves and ridges aligned at the circumference and alternating, these ridges having flats of smooth partitions, cylindrical, and little apart axially, intended to support the felt and to allow the latter to pass over the grooves and consequently protect the strip against significant marks at the first clamping zone, these grooves being connected to the ambient atmosphere on the inlet and outlet sides of the first clamping zone to facilitate the entry of water from the felt and the strip from this first zone, 4 Said grooves are connected to the ambient atmosphere on the inlet and outlet sides of the first clamping zone to facilitate the entry of water from the felt and the strip to this first clamping zone, a scraper being placed against the inlet side of this first zone for removing water from said partition surfaces; 5 Said grooves are connected to the atmosphere <Desc / Clms Page number 58> ambient on the inlet and outlet sides of the first clamping zone to facilitate the entry of water from the felt and web to this first clamping zone, a scanning device having an axially continuous surface extending from the vicinity of said peripheral surface of the cylinder and gradually moving away from it in the direction of rotation of the cylinder to pump the liquid out of the grooves which pass in front of the scavenging device 6 Said grooves are connected to the ambient atmosphere on the inlet and outlet sides of the first clamping zone to facilitate the entry of water from the felt and the strip to this first clamping zone, these grooves forming a continuous spiral on the periphery of the cylinder, a scraper being placed in close proximity to the inlet side of this first clamping zone and removing water from these flat surfaces of the partitions, and a scraper being placed on the on the inlet side of this scraper, this sweeping device having a continuous surface axially extending from the near vicinity of the peripheral surface of said cylinder and gradually moving away from it in the direction of rotation of the cylinder to pump the liquid and make out grooves which pass in front of the scanning device; The assembly comprises a moving felt and forming, a loop, a number of press rolls arranged to form a first clamping zone between press rolls comprising unperforated walls intended to receive the felt with a wet strip for transfer the water from the strip to the felt and a second spin zone between <Desc / Clms Page number 59> press rolls intended to receive the felt alone and to rid it of its water, the wall of the unperforated press roll on which the felt is wound on the first tightening zone having a peripheral surface part comprising a certain number alternating grooves and ridges, aligned on its circumference, these ridges having surfaces of flats of cylindrical partitions, not far apart axially, intended to support the felt and to allow it to pass over the grooves and therefore protect the strip in this way against a significant marking in the first clamping zone, 'these grooves being connected to the 'ambient atmosphere on the inlet and outlet sides of the first clamping zone to facilitate the entry of water from the felt and the strip into this first zone, guiding devices separating the strip of the felt and the felt from the cylinder a press around which it is wound immediately upon exiting the first clamping zone, and a trough placed between the felt and the press cylinder on which it winds, immediately upon exiting the first clamping zone; 8 A second wiping zone between the press rolls is intended to receive the felt alone and to rid it of its water, at least one of the press rolls in contact with the felt in one of the wiping zones having an unperforated press cylinder wall having a portion of its peripheral surface having alternating grooves and ridges aligned around its circumference, these grooves having an axial dimension at the periphery of the cylinder which is sufficiently <Desc / Clms Page number 60> large to receive the liquid squeezed out of the strip but which is small enough to prevent the liquid from coming out of the groove under the action of centrifugal force, these grooves forming a continuous spiral on the periphery of the cylinder, and a scanning device having an axially continuous surface portion extending from the near vicinity of the peripheral surface of the cylinder and gradually moving away from it in the direction of rotation of the cylinder to pump the liquid out of the passing grooves in front of the scanning device; 9 A scraper is placed on the inlet side of the clamping area formed by one of these press rollers and on the outlet side of the sweeper to remove water from the surfaces of the bulkhead flats before the clamping area: The press section of a papermaking machine has a moving felt forming a loop, a number of press rolls arranged to form a first press clamping zone between press rolls comprising unconfined roll walls. perforated, intended to receive the felt with a wet strip for transferring water from the strip to the felt and a second press wringing zone between press rolls intended to receive the felt alone and to rid it of its water, the non-perforated press cylinder wall on which the felt is wound at the first clamping area having a peripheral surface <Desc / Clms Page number 61> comprising a number of alternating grooves and ridges aligned on its circumference, these ridges having smooth partition flat surfaces, cylindrical and not very far apart axially intended to support the felt and to allow it to pass over the grooves and consequently to protect the strip against significant marking in the first clamping zone, these grooves being connected to the ambient atmosphere on the inlet and outlet sides of the first clamping zone to facilitate the entry of water from the felt and web to this first clamping zone and the press cylinder outside the loop of the felt into this second wiping zone comprising an unperforated rotating body having a peripheral surface comprising grooves and alternating ridges aligned on its circumference, these grooves having an axial dimension at the periphery of the cylinder which is large enough to receive the water squeezed out of the felt but which is small enough to prevent liquid from coming out of the groove under the action of centrifugal force has The grooves on each of these cylinder surfaces form a continuous spiral at the periphery of the cylinder, and a scanning device works in association with each of these grooved rolls, this scanning device having an axially continuous surface portion extending from the near vicinity. from the peripheral surface of the cylinder and gradually moving away from it in the direction of rotation of the cylinder to pump the liquid or bring it out of the grooves which pass in front of the sweeping device; <Desc / Clms Page number 62> 12 A cylindrical press cylinder body is intended to be mounted to rotate about its central axis and to press a portion of its rotating peripheral surface against a liquid-containing strip, this surface having alternating grooves and ridges aligned with its aircon - ference, those grooves having an axial dimension at the periphery of the cylinder which is large enough to receive the liquid expressed from the strip but small enough to prevent liquid from flowing out of the groove under the action of force centrifugal, the ridges having flat surfaces of external peripheral walls, cylindrical, smooth, a continuous scraper axially removing the liquid from these flat surfaces of partitions during the rotation of the cylinder, and a sweeper being placed on the inlet side of the scraper in the direction of rotation of the cylinder, said sweeper having an axially continuous surface portion extending from the near vicinity of the peripheral surface of the cylinder and therefrom. gradually spreading in the direction of rotation of the cylinder to pump the liquid out of the grooves passing in front of the sweeper The assembly comprises a first smooth press cylinder, a second press cylinder forming a first clamping area with the first cylinder, a loop-shaped felt wrapped around the second cylinder and passing through the first clamping area with a wet fiber web, a third press cylinder outside the felt loop, a fourth press cylinder outside the <Desc / Clms Page number 63> bend ae felt and forming a wiping zone for felt alone with the third cylinder, the second and fourth press cylinders having a number of alternating grooves and ridges) aligned on their circumference these ridges having flat surfaces of partitions cylindrical peripherals intended to support the felt at the wiping zone while the grooves are connected to the ambient atmosphere to receive water from the felt at the wiping zone, and devices working in association with said second and fourth cylinders to remove water from these grooves, away from the spin areas 14 The press section carries a first cylinder, smooth press, a second press cylinder forming with the first cylinder a first press clamping zone, a felt in the form of a loop wrapped around the second cylinder and passing through the first clamping zone with a wet fibrous web, a third press cylinder with the outside of the felt loop forming a press, for felt alone with the second press cylinder, so that the water is transferred from the wet web to the felt at the first press clamping area and the water is removed from the felt at the felt-only press wringing area, this second cylinder having a number of alternating grooves and ridges aligned around its circumference, these ridges having flat surfaces of cylindrical peripheral partitions intended to support the felt at the wiping zone while the grooves are connected to the ambient atmosphere to receive water from the felt at the zone <Desc / Clms Page number 64> wringing and devices working in association with the second press cylinder to remove water from these grooves away from the clamping and wringing areas; The water is transferred from the felt humido zones to the first press clamping zone and the water is removed from the felt to the felt-only dewatering zone; 16 The assembly comprises a first smooth press cylinder, a second press cylinder forming a first clamping area with the first cylinder, a felt forming a loop wrapped around the second cylinder and passing through the first clamping area with a tape wet fibrous, a third press roll outside the felt loop forming a felt press alone with the second press roll, so that water is transferred from the wet web to the felt at the first area press clamp and water is removed from the felt at the felt-only press wringing area, the second and third rolls having a number of alternating grooves and ridges $ around their circumferences, these ridges having flat surfaces of cylindrical peripheral partitions intended to support? the felt to the clamping area while the grooves are connected to the ambient atmosphere to receive water from: the felt at the clamping area, and devices working in conjunction with the second and third press rolls to remove the 'water from these grooves away from the tightening and wringing areas, B. Cylindrical press cylinder body intended for <Desc / Clms Page number 65> be mounted to rotate about its central axis and to present to a pressurized clamping area, a part of rotating peripheral surface, cylinder body characterized by the following points, separately or in combinations! 1 This part of the surface has grooves and ridges circumferentially aligned and alternating, said grooves having an axial dimension at the periphery of the cylinder of 0.127 mm to 0.89 mm and generally extending radially inward on at least 1, About 27 mm between side walls which are axially spaced apart by an amount at least equal to the axial dimension of the groove at the periphery of the cylinder, said ridges having a partition surface at the cylindrical outer periphery, having an axial dimension of 1.27 mm to 3.8 mm, i.e. 3 to 20 times the axial dimension of the groove at the periphery of the cylinder ' 2 The grooved ditas form a continuous spiral on the periphery of the cylinder; 3 Said surface portion of the cylinder body has alternating grooves and ridges aligned around its circumference, these grooves having an axial dimension at the periphery of the cylinder of approximately 0.635 mm and extending generally radially. ment inwardly over approximately 3.175 mm between substantially radial walls, these grooves forming a continuous spiral around the periphery of the cylinder, and these ridges each having a cylindrical outer peripheral partition land surface having an axial dimension approximately 2.54 mm, 4 Said surface part has grooves and <Desc / Clms Page number 66> alternating edges, aligned on its circumference, these grooves having an axial dimension at the periphery of the cylinder which is large enough to receive the liquid squeezed from the strip but small enough to prevent the liquid from coming out of the groove under the action of centrifugal force; and there is provided a scanning device having an axially continuous surface portion extending from the near vicinity of said peripheral surface portion of the cylinder and gradually moving away in the direction of rotation. of the cylinder. for pumping liquid out of the grooves as they pass the sweeping device 5 The grooves form a continuous spiral around the periphery of the cylinder, and the ridges have smooth, cylindrical wall flat surfaces at the outer periphery, a scraper is provided with an axially continuous scraper blade on these bulkhead flat surfaces to 'remove liquid from these bulkhead flat surfaces during the rotation of the cylinder, a scavenger being placed on the' wall. inlet side of the scraper in the direction of rotation of the cylinder, and having an axially continuous surface portion extending from the near vicinity of the peripheral surface portion of the cylinder and departing therefrom in the direction of rotation of the cylinder to pump the liquid out of the grooves as they pass past the scanning device; Said grooves have an axial dimension at the periphery of the cylinder of 0.127 mm to 0.89 mm and said surfaces; <Desc / Clms Page number 67> bulkhead flats have axial dimensions which are 3 to 20 (the axial dimension of a groove on the periphery of the cylinder) ' 7 The assembly comprises a cylindrical press cylinder body having a peripheral surface having alternating grooves and ridges aligned around its circumference, these grooves forming a continuous spiral on the periphery of the cylinder, a device for rotating the cylinder , a device for presenting to these edges a continuous axial edge and a comb sliding on this edge to move axially according to a relative displacement and carrying a certain number of guide devices, spaced apart, aligned on the periphery, sliding in These neighboring grooves at the periphery of the cylinder. C, Device for cleaning a continuously rotating cylindrical press cylinder body comprising a peripheral sutface having alternating grooves and ridges aligned around its circumference, these grooves forming a continuous spiral around the periphery of the cylinder, characterized device by the following points, separately or in combination! 1 It comprises a means intended to present to said edges an axially continuous edge and a comb sliding on said edge to take a relative axial movement, carrying a number of spaced guide devices aligned on the periphery, fitting into neighboring grooves on the periphery of the cylinder and sliding therein 2 At least one of said guide devices extends to the corrugation of the groove from the comb which slides on <Desc / Clms Page number 68> the edge: 3 The grooves form a continuous spiral at the periphery of the cylinder, and this coppa rotates in the close vicinity of an element having in front of its edges an axially continuous edge, the device further comprising a comb sliding on this edge to moving with a relative axial movement and carrying a number of spaced guide devices aligned on its periphery, sliding in neighboring grooves: '., .. at the periphery of the cylinder and comprising a support member having a surface forming an acute angle with the guide devices to hold the comb against said edge during the; cylinder rotation. D, Press section of a papermaking machine for removing water from a web of paper at a press clamping area receiving the web on a felt between two press rolls, characterized by the following, separately or in combinations, ( 1 It comprises a press cylinder body intended to be mounted to rotate around its central axis and to press a part of its rotating surface against the felt, this surface having alternating grooves and ridges, aligned at its circumference, these grooves having an axial dimension at the periphery of the cylinder which is large enough to receive water squeezed out of the strip and felt but small enough to prevent water from coming out of the grooves under the action of centrifugal force, these ridges each having a flat surface of the external peripheral, cylindrical wall having a dimension <Desc / Clms Page number 69> axial which is 3 to 20 times that of the axial dimension of the groove at the periphery of the cylinder, these grooves forming a continuous spiral on the periphery of the cylinder; 2 Said surface portion of the cylinder body has alternating grooves and ridges aligned around its circumference, these grooves having an axial dimension at the periphery of the cylinder of 0.127mm to 0.89mm, which dimension is large enough to accommodate the cylinder. water squeezed out of the tape and felt but small enough to allow the felt to pass over these grooves to protect the tape from any major marks, these grooves being small enough to prevent water from coming out of the grooves under the action centrifugal force, the ridges each having an outer peripheral, cylindrical wall flat surface having an axial dimension which is 3 to 20 times the dimension of the groove at the periphery of the cylinder, 3 The press section of the paper machine comprises a moving wet felt and, forming a loop, a first press cylinder, a second press cylinder in contact with the felt and forming with the first press cylinder a clamping area intended to receive the felt, this second press cylinder having a cylindrical body intended to be mounted to rotate about its central axis and to press a part of its rotating peripheral surface against the felt, this surface part having grooves and alternating ridges, aligned around its circumference, those grooves having an axial dimension at the periphery of the cylinder which is large enough to accommodate the water squeezed out of the tape and felt <Desc / Clms Page number 70> EMI70.1 but which is small enough to prevent water from Bori: ir QlI, hL, t 3 1 grooves, each of the ridges having an outer, cylindrical, peripheral wall flat surface having an axial dimension which is 3 to 20 times the axial dimension of the groove at the periphery of the cylinder, these grooves forming a continuous spiral at the periphery of the cylinder! 4 These ridges each have an outer peripheral, cylindrical wall flat surface, and an axially continuous scraper is placed close to the clamp area to remove water from these wall flats on the inlet side of the clamp area, during the rotation of the cylinders; These ridges each have a flat surface of cylindrical outer peripheral wall, and a scanning device comprising an axially continuous surface portion extends from the near vicinity of and gradually away from the peripheral surface of the cylinder. in the direction of rotation of the cylinder to pump the liquid and. pull it out of the grooves as they pass the sweeper! 6 The felt has a thickness which is approximately between 1.59 mm and 3.175 mm at the clamping area the second press cylinder having a cylindrical body intended to be mounted to rotate about its central axis and to pressing part of its rotating surface against the felt, this surface having alternate grooves and ridges aligned around its circumference, these grooves having an axial dimension at the periphery of the cylinder which is large enough to <Desc / Clms Page number 71> receive water squeezed out of the tape and felt but which is small enough to prevent water from coming out of the grooves, the ridges each having a cylindrical outer peripheral wall flat surface having an axial dimension which is 50 to 200% of the felt thickness at the clamping region: The ridges of the press cylinder shell each have a cylindrical outer peripheral wall flat surface having an axial dimension which is 50 or 200% the thickness of the felt at the clamping area and which is 3 to 20 times the axial dimension of the groove at the periphery of the cylinder, 8 The press section of the machine comprises a moving wet felt forming a loop, a first press cylinder, a second press cylinder in contact with the felt and forming with the first press cylinder a clamping area to receive the felt , this second cylinder having a cylindrical body intended to be mounted to rotate around its central axis and to press a part of its rotating peripheral surface against the felt, this surface having alternating grooves and ridges, aligned with its oirconference, these grooves having an axial dimension at the periphery of the cylinder which is large enough to accommodate the water squeezed out of the strip and felt but small enough to prevent water from escaping the grooves under the action of centrifugal force, the ridges having each a flat surface of a cylindrical external peripheral partition, a continuous scraper <Desc / Clms Page number 72> axially being mounted near the Clamp Zone to remove water from those bulkhead flats on the inlet side of the Clamp Zone during the rotation of the cylinders and a wiper being mounted on the inlet side of the scraper in the direction of rotation of the cylinder, said scavenging device having an axially continuous surface portion extending from closely adjacent to the peripheral surface of the cylinder and gradually moving away from it in the direction of rotation of the cylinder for pumping liquid and squeeze it out of the grooves passing in front of the sweeper) 9 The ridges on the surface of the press cylinder each have an outer cylindrical peripheral partition land surface having an axial dimension of 3 to 20 times the axial dimension of a groove at the periphery of the cylinder, these grooves forming a spiral. continues on the periphery of the cylinder; The press section for removing water from a web of paper in a clamping area receiving the web on a felt between two press rolls, comprises a cylindrical body intended to be mounted to rotate about its central axis and pressing a part of its rotating peripheral surface against the felt, this surface part having alternating grooves and ridges aligned around its circumference, these grooves having an axial dimension at the periphery of the cylinder which is quite large to accommodate the water expelled from the tape and felt but which is small enough to prevent water from exiting the grooves under the action of force <Desc / Clms Page number 73> EMI73.1 centrifugal, the thickness of the felt in the pincer areaGrG4! f 9 being approximately 1.59 mm to 3.175 mm, and the ridges each having an outer peripheral, cylindrical wall land surface having an axial dimension which is from 3 to 20 times the axial dimension of the groove at the periphery of the cylinder and from 50 to 200% the thickness of the felt in the clamping zone; 11 The press section comprises a moving wet felt forming a loop, a first press cylinder, a second press cylinder in contact with the felt and forming with the first press cylinder a press clamping area for receiving the felt , this second press cylinder having a cylindrical body intended to be mounted to rotate about its central axis and to press a part of its rotating peripheral surface against the felt, this surface part having alternating grooves and ridges, aligned with its circumference, those grooves having an axial dimension at the periphery of the cylinder which is large enough to accommodate the water squeezed out of the tape and felt but which is small enough to prevent water from coming out of the grooves under the action of force centrifugal, said ridges each having a cylindrical outer peripheral bulkhead land surface, a continuous scraper axially near the clamping area for removing water from those bulkhead flat surfaces on the inlet side of the clamping area during rotation of the cylinders , and guiding devices of said felt separating it from the surface part of the <Desc / Clms Page number 74> cylinder immediately on the inlet and outlet sides of EMI74.1 , a-clamping area =. - - ', -.,] ""' ... ". '12 The felt guiding devices separate ;; the latter from the surface of the cylinder immediately upon entering and leaving the clamping area. 'generally along a plane tangent to the two cylinders.