System for providing improved dewatering performance in a papermaking machine

ES 2 666 331 T3

DESCRIPTION

System for providing improved dewatering performance in a papermaking machine

Priority

This application claims priority from US Patent Document Serial No. 61 / 146,885 filed on January 23, 2009.

Background

1. Field of the invention

This invention relates to doctor blade systems, and is particularly concerned with an improved design that facilitates water or debris removal performance while maintaining the desired performance of the doctor blade holder.

two. Description of the prior art

Many roll cleaning and sheet peel applications in paper machines and other web handling applications include doctor blade holder devices commonly referred to as doctor blade holders. Typically, a scraper blade holder is mounted on a back of the scraper blade, which is a sturdy bundle that spans the width of the paper machine. The rear portion of a doctor blade is inserted into the holder, which holds the blade in a predetermined position relative to the surface to be cleaned. The holder works in concert with the scraper assembly to apply the working edge of the blade, which is located at the front of the blade, to an adjacent moving surface.

Certain conventional scraper apparatuses for paper machines are equipped with double scrapers; The primary scraper cleans the surface of the roll, while the secondary blade removes water and dirt that may have come loose from machined features, such as through holes, blind holes, or grooves on the moving surface, usually under the effect of force. centrifugal, with some additional influence from a reduction in the surface tension of the fluid. However, this is often not enough to adequately drain the rolls.

US Patent Document. No. 6,491,791 discloses a method and apparatus for cleaning roll or fabric surfaces used in papermaking machines, wherein a scraper element includes one or two integral scraper blades as well as an integral gas chamber that provides pressurized gas, for example , compressed air, to the projecting side of a scraper apparatus having one scraper blade and to the interblade area of ​​a scraper apparatus having two scraper blades. Compressed air is provided to improve water or dirt removal capabilities. Each of the disclosed apparatus, however, involves scraper blades that are integral with the structure that forms the gas chamber within the scraper element.

The use of these integral scraper blades requires the entire scraper element to be replenished every time the scraper blades become too worn. It is also not disclosed that the scraper apparatus is adjustable in position relative to the roll, and it is not entirely clear how an integral gas chamber can be incorporated into a scraper apparatus that provides adjustable positional accuracy relative to a roll, as well. as flexibility to scrape a roll along an elongated length of the doctor blade. Other shortcomings of such systems include: 1) The apparatus is not integral with the stand. 2) The appliance is part of the blade and therefore when it is worn or damaged it must be replaced, which is very expensive. 3) The apparatus is very rigid and does not have the ability to adapt well to the surface of the roll. 4) Air discharge characteristics and geometry used for dewatering may not produce adequate dewatering. 5) The air discharge of the device is always open, which allows the entry of pollutants from the environment when the device is not pressurized; The entry of contaminants can be avoided by applying pressurized air when the machine is under maintenance, but with the disadvantage of the additional cost associated with it.

Patent document US 6,139,638 discloses a scraper blade holder apparatus including a flat upper support member that is pivotally mounted on a tray so that the position of the upper support member relative to the tray can be adjusted by unloading and loading tubes. The upper support member also includes a plurality of distribution passages that are respectively coupled outside of the upper support member through a plurality of bypass conduits to a common manifold. The pressurized fluid, therefore, must travel separately through the conduits to reach each of the individual areas along the scraper blade apparatus, while maintaining a sufficiently equalized pressure as the fluid is directed into the roll along the elongated length of the scraper blade.

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Document US 5,021,124 discloses a double scraper for a paper machine, comprising a first scraper blade and a second scraper blade, which are equipped to scrape the same face of the roll. The double scraper includes a first scraper bundle and there a first scraper blade as well as a second scraper bundle and therein a second scraper blade. The first scraper bundle and the second scraper bundle are interconnected at their ends by means of end plates, whereby an opening remains between the scraper bundles and the end plates, through which the paper material or web is opened scraped off the face of the roll can be freely passed into a pulper. US Patent 5,021,124 also discloses a method for adjusting the double scraper. The pressure fluid is provided through openings in the scraper blade holder. It is therefore still necessary for a cost-effective scraper blade holder system that facilitates the constant removal of debris without limiting the flexibility of the scraper blade system or the efficiency of the scraping process, and in particular that improves the dewatering performance of an appliance. scraper that works on various paper machine rolls, while preserving or improving the cleaning performance of the scraper blade, such as on a paper machine suction press scraping machine.

Resume

The invention is defined in the independent claim, to which reference should now be made. Furthermore, optional features can be found in the subclaims appended hereto.

In accordance with one embodiment, the invention provides a scraping system for a papermaking machine in which the scraping system includes a doctor blade and a fluid assist means. The scraper blade is attached to a scraper blade holder and is for cleaning a moving surface. The scraper blade holder is attached to the back of the scraper. The fluid assisting means is to provide a fluid under positive pressure that is higher than atmospheric pressure and is directed in a direction generally along a direction of movement of the moving surface so that a negative pressure that is lower at atmospheric pressure develops in a negative pressure zone adjacent to the moving surface and a tracking surface of the scraper blade during movement of the moving surface

According to another embodiment, the doctor blade is for dewatering a roll including holes, and the fluid assisting means is for providing air at positive pressure that is greater than atmospheric pressure. The air is directed in a direction generally along a direction of rotation of the roll so that a negative pressure less than atmospheric develops in a negative pressure zone adjacent to the movable surface and a subsequent surface of the doctor blade during rotation of the roll to draw water from within the holes in the surface of the roll.

Brief description of the drawings

The following description can be better understood with reference to the accompanying drawings in which:

Figure 1 shows an illustrative diagrammatic view of a scraping system in accordance with one embodiment of the invention;

Figure 2 shows an illustrative schematic view of the underside of the scraper blade holder shown in Figure 1;

Figures 3A and 3B show illustrative schematic views of the scraper blade holder of Figure 2 with evenly spaced apertures and with irregularly spaced apertures respectively;

Figure 4 shows an illustrative schematic view of a scraping system in accordance with another embodiment of the invention;

Figure 5 shows an illustrative diagrammatic view of the underside of the doctor blade and the doctor blade holder of Figure 4;

Figure 6 shows an illustrative diagrammatic view of the proximal side of the doctor blade and doctor blade holder of Figure 4;

Figures 7 and 8 show illustrative schematic views of scraping systems in accordance with other embodiments of the invention;

Figures 9 and 10 show illustrative schematic views of the underside of the doctor blades and doctor blade holder according to other embodiments of the invention;

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Figures 11 and 12 show illustrative schematic views of the underside of a doctor blade and a doctor blade holder in accordance with other embodiments of the invention; Y

Figures 13-16 show illustrative schematic views of scraper systems in accordance with other embodiments of the invention.

Drawings are for illustrative purposes only and are not necessarily to scale.

Detailed description of the drawings

The present invention provides an improved scraping device for dewatering paper machine rolls, such as suction press rolls, in which features machined on the roll or other moving surface such as through holes, blind holes (partially drilled holes) and grooves remove unwanted water that needs to be removed. The scraper device includes several features including dewatering ability. The flexibility of the scraper device is retained by making the dewatering characteristics integral with the loading characteristics of the support in certain embodiments. This is accomplished through the use of fiber reinforced pultrusion or metal extrusion.

The device includes a plurality of mounting structures that are integrally formed as a result of the extrusion or pultrusion process in certain embodiments. In addition, the conventional doctor blade wear item can be retained to clean the roll surface, and remains a separate low-cost consumable component. Proper support with drainage characteristics never requires replacement due to wear. Air would be adequate for most applications, although the systems of various embodiments of the device of the invention are also suitable for use with other fluids, such as steam, or even liquids.

According to one embodiment, the invention provides a flow and mechanical device assembly that is used to scrape paper machine rolls that carry, for example, water. The figure. 1 shows an embodiment of such a system in which the system includes a separate scraper blade 10 for application to a roll 12 that rotates in a direction as seen at 11. Scraper blade 10 is removably housed within a receiving area of ​​a scraper blade holder 14. Scraper blade holder 14 is coupled through a tubular tray 16 (which is attached to a scraper backing 18) by a mounting frame 24 which is integral to the scraper blade holder 14, which are attached to structures 26 on the tubular tray by a rod 28. Discharge tube 20 and loading tube 22 (generally referred to as loading tubes 20, 22) alternately extract or apply scraper blade 10 to the surface of roll 12 by alternately introducing or releasing a fluid pressure within the tubes. load 20, 22.

Positive pressure fluid is provided to distribution chamber 30, and is released from distribution chamber 30 through one or more openings 32. The one or more apertures 32 may comprise a series of apertures along the elongated width of scraper blade holder 14 as further shown in Figure 2, or in accordance with other embodiments, may comprise a single elongated aperture or slot as shown. discussed further below, for example, with reference to Figures 4-6. The mounting device is loaded via the charging tubes 20, 22 in a conventional manner, and includes the integral distribution chamber 30 within the scraper blade holder 14 to supply pressurized air through the discharge opening 32. Assembly includes separate scraper blade 10 that can be removed and replaced without disturbing the positive pressure assembly.

The scraper blade holder 14 may be formed of a fiber reinforced pultrusion, or it may also be a metal extrusion therein or other embodiments. The pultrusion may include a mounting structure 24 that is integrally formed as a result of the pultrusion or extrusion process, as further shown in Figure 2. In accordance with other embodiments, mounting structure 24 may be provided as a series of integrally formed mounting structures as explained below, for example, with reference to Figures 4-6. The device mount can be used to remove water from rolls with holes (either through through holes or knockouts), to remove water from rolls with such holes and grooves, or to remove water from other moving surfaces in one operation. papermaking such as mobile networks. In other embodiments, the dispensing chamber feature can be integrated into the stationary tube holder or can be mounted directly to the back of the scraper.

The series of openings 32 in the scraper blade holder 14 adjoins the distribution chamber 30, and allows fluid such as air to be released from the distribution chamber as shown at A in Figure 1 in a direction that is generally along the along a direction of roll rotation, causing a low pressure area to develop between the blade tracking surface 10 and the roll surface 13 as shown at B. The low pressure draws water out of the holes 15 in the roll 12. The holes 15 can be through holes or blind holes. The

ES 2 666 331 T3 air shower is directed mainly parallel but slightly towards the roll, rather than away from the roll. A boundary wall 35 helps guide air in the desired direction.

The main function of the integral flow distribution chamber and discharge is to create a vacuum under the holder and the blade as shown at B in Figure 1, to help the centrifugal force to evacuate the water residing in the holes 15 Referring back to Figure 2, the apertures 32 should not be spaced too far apart, and if they are spaced too far, a reserve stream of fluid may develop between the apertures as shown at 33. These discrete openings, therefore, can have the disadvantage of introducing a flow path to replenish air back upstream between the openings if they are spaced too far apart. To limit this sealing deficiency, the openings should be spaced less than one inch (25.4 mm) apart. Opening spacing of more than 25.4 mm (one inch) allows for increasingly additional make-up air, compromising (reducing) the vacuum level. The use of such a scraper blade holder, which contains both the fluid nozzle and the fluid supply distribution chamber, is well suited for both upgrades of existing scraping equipment (e.g. direct adaptation for DST-E holders) and for new facilities.

Figure 3A illustrates that for those cases where the machine is large, an air pressure drop in the central region within the chamber can be large enough to make the distribution chamber pressure not uniform as shown. shown at 34, that is, the pressure may be higher near the inlets 36, 38 of the distribution chamber 30 of the scraper blade holder 14, and lower near the center as shown at 37. This will cause non-uniform air discharge and may have some non-uniform influence on water removal. To compensate for this pressure bias of the dispensing chamber, the aperture spacing can be variable (for example, the apertures may be closer to each other near the middle 37 'for a dispensing chamber 30' of a scraper blade holder 14 'than at ends 36' and 38 ') to compensate for pressure variation, thus keeping the air discharge flow rate uniform as shown at 34' in Figure 3B.

The air discharge opening may be, according to another embodiment, a continuous slot, with the air shower again directed mostly parallel, but slightly towards the roll, rather than away from the roll. In particular and as shown in Figures 4 and 5, a distribution chamber 40 is provided within a doctor blade holder 42 which also includes integrated mounting structures 44 as well as a blade receiving portion 46 for receiving a doctor blade 48. Integrally formed mounting frames 44 are coupled to integrally formed mounting frames 50 on a tube tray 52 via a rod 54. Tube tray 52 may also include an integral scraper backing mounting structure 56 to engage a rear backrest 57. Loading tubes 58 and 60 are used to position the blade against a surface 62 or roll 64 as discussed. above with reference to the charging tubes 20, 22 of Figure 1.

A continuous slot opening 66 in scraper blade holder 42 abuts distribution chamber 40, and allows fluid such as air to be released from the distribution chamber as shown at C in a direction that is generally along rotation. of the roll (shown at 63), causing a low pressure area to develop between the blade tracking surface 48 and the roll surface 62 as shown at D. The low pressure draws water from within the holes 68 and slots 69 in the roll 64.

A boundary wall 43 helps guide the air in the desired direction. The high velocity air shower interacts with the resident ambient air below the holder, imposing significant shear on it, thus drawing the resident air in the direction of flow that matches the direction of rotation of the roll. This through airflow under the bracket is replenished by air intake from unsealed locations around the bracket. Since the groove is continuous, it in principle seals the flow of make-up air which will otherwise tend to flow back upstream in the unoccupied volume below the holder and blade.

As shown at E in Figure 6, a source of replenishment air comes from the edges of the blade and holder. As long as there is resistance to the make-up airflow, a vacuum will be created under the holder and blade, and that vacuum will help to dislodge the water from the holes. Higher vacuum levels can be achieved by increasing the discharge air flow rate and decreasing the make-up air flow. On the contrary, the through-air flow under the blade and the holder can be raised by increasing the discharge flow rate of the air distribution chamber and replenishing the air through the edges of the blade. In some applications it may be more advantageous to achieve only nominal vacuum, rather than maximizing vacuum, and instead combine higher replenishment flow rates (through the ends) with nominal vacuum, to help transport machine resident water high-speed, such as in fabric-making machines.

As shown in Figure 7, the air discharge area (as shown at 70), either through the continuous slot or series of holes, is located as close as possible (as shown at 74) to travel of through air 72, to allow the most effective cut of resident air, producing greater vacuum. The air discharge area 70 should also be located near the boundary wall 43 (as shown at 76) of the scraper blade holder 42 to produce high vacuum in an area 78 below the tracking surface of the scraper blade 48.

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In accordance with a further embodiment as shown in Figure 8, a discharge opening 80 (provided either as a series of holes or a continuous slot) is in communication with a distribution chamber 82 in a scraper blade holder 84. The discharge opening 80 is also in communication with a preloaded diverter plate spring 86 (formed for example of a synthetic or metallic material) having a discharge end portion 87 that will open to a desired continuous space under pressure, delivering the proper air flow discharge under operating conditions. The preloaded deflector plate spring 86 may be formed into an elongated shape that is received within a complementary elongated shaped recess within the doctor blade holder as shown. Scraper blade holder 84 may also receive scraper blade 88 in a receiving area 90 to clean a surface 92 of a roll 94 that rotates in a direction as indicated at 93. Roll 94 can include holes (through or blind) as well as grooves as discussed above. When air discharge is not needed, the pressure is turned off and the flap will close the gap, preventing the entry of unwanted contaminants. In the absence of the pre-charged diverter plate, pressurized air may be required to prevent contaminants from entering the distribution chamber during machine outages.

To limit replenishment of air entering through the edges of the blade and bracket, two or more features of the wall wrapped around the scraper blade as shown in Figures 9 and 10, can be added to the scraper blade holder, or both as shown in Figures 11 and 12. In particular, as shown in Figure 9 a cover 100 may be located at each of the two ends (one of which is shown) of a doctor blade 102. The covers inhibit the entry of make-up air into the area below the doctor blade 102. The doctor blade 102 is coupled to a doctor blade holder 104, which in turn is coupled to a tube tray 106 as discussed above. Air is provided to distribution chamber 108 through conduit port 110, and distribution chamber 108 includes a sealed end structure 112 through which hole 110 communicates with distribution chamber 108. An opening in the form of a continuous slot 114 (or series of openings) is in communication with the distribution chamber 108 as discussed above to provide a discharge of a fluid such as air that is directed mainly parallel, but slightly towards the roll. .

As further shown in Figure 10 (where like elements are designated by the same reference numerals as in Figure 9, the scraper blade 102 may further include a plurality of intermediate covers 116 that are positioned at separate locations along the bottom side of scraper blade 102.

As shown in Figures 11 and 12, a cover 120 can be located at each of the two ends of a scraper blade 122 (again only one is shown), and a cover 124 can be located at each of the two. ends (one shown) of a scraper blade holder 126. Covers 120 prevent make-up air from entering the area below the doctor blade 122 and covers 124 prevent make-up air from entering the area below the doctor blade holder 126. The doctor blade 122 is coupled to the doctor blade holder 126, which in turn is coupled to a tubular tray 130 as discussed above. Air is provided to distribution chamber 132 through conduit port 134, and distribution chamber 132 includes a sealed end structure 136 through which port 134 communicates with distribution chamber 132. Aperture 128 is in the form of a continuous slot and is in communication with distribution chamber 132 as discussed above to provide a discharge of a fluid such as air that is directed primarily parallel but slightly toward roll 140 when rotated in one direction. as stated in 139.

As further shown in Figure 12, covers 120 and 124 (as well as covers 100 and 116 in Figures 9 and 20), are positioned near surface 138 of a roll 140 to be processed. The covers 100, 116 and 120 can be formed integral with the doctor blade and the covers 124 can be formed integral with the doctor blade holder.

The doctor blade will wear out as a result of contact with the roll surface. As the blade wears, the holder and integral distribution chamber will rotate and move onto the roll. As your position and orientation to the roll surface changes, performance will change. To maintain a nearly constant position on the roll surface for long periods of time, the preferred blade geometry is one where the blade wear rate is low; One such blade is one in which the wrapped end is reproduced periodically along its length, as discussed above with reference to Figure 10. Alternatively, the thicker covered profile can be extruded along the blades over their entire length, resulting in a blade of constant thick cross section. Such a thick cross-sectional blade also offers an advantageous edge replacement air seal, whereby together with the scraper blade holder it increases the vacuum levels under the scraper blade holder.

The doctor blade holders of certain embodiments of the present invention are designed to receive a single doctor blade as previously disclosed. The individual scraper blades of the scraper retain great flexibility along the elongated direction. Flexibility is important to allow the blade to overcome misalignment and crowned roll surfaces, as well as other variations. This flexibility is a determining factor

ES 2 666 331 T3 principle of effective scraping and Increasing this flexibility has been the goal of blade and scraper assembly design for decades. The use of an integral doctor blade and doctor blade holder, as described, for example, in US Patent No. 6,491,791) inhibits flexibility and decreases the effectiveness of scraping. Specific to the dewatering application, the rigid blade would have a difficult time negotiating the roll surface and as such would allow make-up air to pass under the blade tip at non-contact locations, diluting the vacuum. The elimination of the water would be compromised.

Certain prior art scraper systems include grafted product wear components (scraper blades) in major elements (scraper assemblies) that require removal of the entire major article when the product wear article is depleted. Rather, the present invention keeps the scraper blade of the wear item separate from the important item, requiring replacement of only the scraper blade to restore the scraper assembly to its original performance level.

Figure 13 shows a further embodiment of the invention in which a separate flow device member 150 including a distribution chamber 152 and one or more apertures 154 is attached with fasteners 156 to a top plate 158 of a scraper system. A scraper blade 160 is attached to member 150, and top plate 158 is rotatably coupled to a tube tray 162. In this case, the flow device member 150 also provides the necessary support for the underside of the doctor blade 160. Preferably, this flow device member is made of a pultruded fiber reinforced plastic (FRP) or metal extrusion. The roll-oriented outer profile of this flow device element, together with the air discharge orientation, is identical to that of the first embodiment described above. Tube tray 162 includes loading tubes 164 and 166 (as discussed above), and is coupled to a back of scraper 168. The scraper blade cleans a surface 170 of a roll 172 as discussed above while such a fluid as air that is provided to the distribution chamber 152 is directed through the one or more apertures 154 to provide dewatering of the roll 172 as the roll rotates in a direction as indicated at 171.

Figure 14 shows a further embodiment of the invention in which the flow device element 180 is made of a metal such as stainless steel rather than a pultruded fiber reinforced plastic (FRP) or metal extrusion. Separate flow device element 180 includes an internal distribution chamber 182, an intermediate distribution chamber 184, and one or more openings 186 (as discussed above). Member 180 is attached with fasteners 186 to a top plate 188 of a tube tray 190 that includes loading and unloading tubes 192, 194. Tube tray 190 is attached to a back of scraper 196. A scraper blade 198 is attached to the top plate 188, and the top plate 188 is rotatably coupled to a tube tray 190. The doctor blade cleans a surface 200 of a roll 202 when rotated in a direction as indicated at 201 as discussed above, while a fluid such as air is provided to the distribution chamber 182. The fluid such as air from the The interior of the distribution chamber 184 is directed through the one or more openings 186 to provide drainage of the roll 202 as discussed above.

Figure 15 shows a further embodiment of the invention in which the flow device element 210 is an integral part of the tube tray 212 of a scraper system. This flow device member 210 and tube tray element 212 may be made from a pultruded fiber reinforced plastic (FRP) or metal extrusion, or they could be made from a metal such as stainless steel. The outer, roll-oriented profile of this flow device element, along with the orientation of the fluid discharge opening 214, is the same as in the previous embodiments mentioned above. Flow device element 210 includes an internal distribution chamber 216 and one or more openings 214 for providing fluid such as air generally along surface 218 of roll 220 that rotates in a direction as indicated at 119 as described previously. A top plate 222 is rotatably coupled to tube tray 212, and a scraper blade 224 is attached to top plate 222. The movement of the scraper blade 224 with respect to the tube tray 212 is provided by loading and unloading the tubes 226 and 228 as discussed above. The doctor blade cleans the surface 218 of the roll 220 as discussed above while a fluid such as air that is provided to the distribution chamber 216 is directed through the one or more apertures 214 to provide dewatering of the roll 220 as discussed. previously.

Figure 16 shows a further embodiment of the invention in which the flow device element 230 is attached with fasteners to a rear portion of the scraper 232 in close proximity to the doctor blade 234 and the doctor blade 236. The flow device element 230 includes a distribution chamber 238 and one or more apertures 240 for providing fluid generally along the surface 242 of a roll 244 as described above. Element 230 is directly attached to the back of scraper 232, and a tube tray 246 is attached to the rear of scraper 232, while top plate 234 is rotatably coupled to tube tray 246. Movement of the Scraper blade 236 with respect to tube tray 246 is provided by loading and unloading tubes 248 and 250 as discussed above. Preferably, this flow device element and tube tray element is made of a pultruded fiber reinforced plastic (FRP) or metal extrusion. The outer, roll-oriented profile of this flow device element, together with the orientation of the nozzle, is identical to that of the first embodiment described above. The doctor blade cleans the surface 242 of the roll 244 as discussed above while a fluid such as air is provided to the chamber

Distribution 238 is directed through the one or more apertures 240 to provide dewatering of roll 244 as discussed above.

Those skilled in the art will appreciate that numerous modifications and variations can be made to the embodiments described above without departing from the spirit and scope of the invention.

For the avoidance of doubt, the current application extends to the subject matter described in the following numbered paragraphs (called "To" or "Paras"):

1. A scraping system for a papermaking machine, said scraping system comprising:

a scraper blade coupled to a scraper blade holder, said scraper blade for cleaning a moving surface, and said scraper blade holder is attached to the scraper back;

the fluid assisting means for providing a fluid under positive pressure pressure that is higher than atmospheric, said fluid being directed in a general direction, along a direction of movement of the moving surface such that a negative pressure that is lower than atmospheric pressure develops in a negative pressure zone adjacent to the moving surface and a tracking surface of the scraper blade during the movement of the moving surface.

two. The scraping system according to paragraph 1, wherein said scraper blade holder is formed of a pultruded material.

3. The scraping system according to paragraph 2, wherein said pultruded material includes a polymeric resin and fiber composite material.

Four. The scraping system according to paragraph 1, wherein said positive pressure fluid is provided from a distribution chamber within the scraper blade holder.

5. The scraping system according to paragraph 1, wherein said pressurized fluid is provided from a distribution chamber that is structurally separate from the scraper blade holder.

6. The scraping system according to paragraph 5, wherein said distribution chamber is connected to one of the scraper blade and the scraper blade holder of the scraper blade.

7. The scraping system according to paragraph 5, wherein said distribution chamber is attached to the back of the scraper.

8. The scraper system according to paragraph 1, wherein said fluid aid means is formed as a separate structure from the scraper blade, allowing the scraper blades to be attached and removed from the scraper system without affecting the assist means fluid.

9. The scraping system according to paragraph 1, wherein said positive pressure fluid is provided from a distribution chamber through an elongated opening in the scraper blade holder.

10. The scraping system according to paragraph 1, wherein said fluid is provided under positive pressure from a distribution chamber through an elongated opening in the scraper blade holder, said opening formed by deflection of a diverter plate spring.

eleven. The scraping system according to paragraph 8, wherein said diverter plate spring is preloaded against the scraper blade holder, thus sealing the distribution chamber from external contaminants during a machine outage.

12. The scraping system according to paragraph 1, wherein said fluid is provided under positive pressure from a distribution chamber within the doctor blade holder through a plurality of openings along an elongated portion of the doctor blade holder.

13. The scraping system according to paragraph 12, wherein said plurality of openings along the elongated portion of the scraper blade holder are mutually spaced from one another in an uneven manner to facilitate a uniform discharge flow of the fluid along the elongated width of the scraper blade holder.

14. The scraping system according to paragraph 1, wherein said fluid is provided under positive pressure from a distribution chamber within a distribution chamber structure that is coupled to the back of the scraper.

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fifteen. The scraping system according to paragraph 1, wherein said scraper blade holder includes a plurality of mounting structures disposed along at least a portion of an elongated length of a scraper blade, said plurality of mounting structures to facilitate pivotally coupling the blade holder scraper to the back of the scraper.

16. The scraper system according to paragraph 1, wherein said mounting structures help to pivotally couple the scraper blade holder to the back of the scraper by attaching the scraper blade holder to a tube tray including at least one position adjustable tube.

17. The scraping system according to paragraph 1, wherein said mounting structures are integrally formed with the scraper blade holder.

18. The scraping system according to paragraph 1, wherein said scraping system further includes cover walls at each elongated end of the scraper blade holder adjacent the movable surface.

19. A scraping system for a papermaking machine, said scraping system comprising:

a doctor blade coupled to a doctor blade holder said doctor blade for dewatering a roll including holes, and said doctor blade holder is coupled to a doctor back;

fluid assist means to provide air under positive pressure that is greater than atmospheric pressure, said air is directed in a general direction along a roll rotation direction such that a negative pressure that is lower than atmospheric pressure develops negatively in a pressure zone adjacent to the moving surface and a surface doctor blade tracking during roll rotation to draw water from within the holes in the roll surface.

twenty. A method of treating a roll surface during papermaking, said method comprises the steps of:

attach a scraper blade holder to a back of the scraper using;

pivotally adjust the scraper blade with respect to the back of the scraper; and providing a positive air pressure that is higher than atmospheric pressure, said positive air pressure that causes the air to be directed in a direction that is generally towards a direction of rotation of the roll so that a negative pressure that is more Low atmospheric pressure is provided in an area of ​​negative pressure adjacent to a surface of the roll and adjacent to a tracking surface of the doctor blade during rotation of the roll.