JPS6183394A - Apparatus and method for conditioning felt for papermaking machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a felt conditioning device that has particular application for paper machines of the type in which a moving felt absorbs moisture from paper or cardboard formed by the paper machine. To ensure efficient machine operation, it is necessary to dewater the felt and remove other materials picked up by the felt from the paper wrapper, such as loose fibers, clay, etc.

PRIOR ART AND ITS PROBLEMS In the press section of a paper machine, upper and lower endless compression fels are used to remove moisture from some paper or cardboard. In order for the endless felt to function properly, it is necessary to remove all water absorbed by the felt with each revolution, otherwise the felt will become supersaturated. To ensure that the felt is properly conditioned, i.e. that water is removed to allow the felt to absorb the maximum amount of water from the paper stock, remove the felt from the felt before it reaches the press mesh. It is especially important to remove absorbed water.

Conventional practice has been to operate the paper machine in a humidified state, i.e. to monitor the back flow of water against the input side of the anastomosis of the press - a clear indication that the felt is oversaturated. . Does the suction box for felt adjustment measure the amount of water absorbed by the felt during each felt operation cycle? Since it is not removed, a humid state of interlocking occurs.

When the felt roller is moved in a supersaturated state at approximately 910 m/min (3000 fpm), (lO
) Requires a reduction in the pressure at the meshing part to remove fine fibers from the paper material under the pressure of the filtration water and to avoid water output forces that may damage the paper material.

In theory, as the pressure at the interlocking area decreases, less water is removed from the paper material.

Therefore, conventional techniques for conditioning felts in paper machines in motion have individual limitations to ensure that the press felts are not properly dried.

When adjusting felt using a suction box, is the saturated felt placed under the felt in the paper machine? Approximately 910 m/min (910 m/min) passing through a vacuum port or slot extending across the
At a machine operating speed of 30 [10 fpm'), any part of the felt has a residence time of 1.6 milliJ seconds above the 1 inch vacuum slot. As the speed of the paper machine increases, this residence time decreases, limiting the amount of water that can be drawn by the vacuum through the slot.

Furthermore, the removal of moisture from the moving felt to the suction box is as follows:
In order to deflect each droplet of moisture moving with the felt at the speed of the paper machine, the action of suction air is required to force it through the felt.

As paper machine speeds increase, more air force is required to remove moisture from the felt. In order to overcome these limitations and to increase the amount of water removed as the operating speed of the paper machine increases,
The use of suction slots in Y-T can be achieved, but the trade-off for such an improvement is a shorter felt life.

In practice, since the contaminants to be removed are present on the paper sheet side of the felt, a suction box is installed against the claw side of the felt. Because of this, the suction box will wear out the fuzz of the felt, and the moisture of the felt? Ability to attract? diminish. The suction box is also attached to the horizontal portion of the two-piece felt after the claw side of the felt has passed over the outer roll, forcing the foreign material against the felt before reaching the suction box.

Another technique for felt conditioning is Cardincr
It is a nicum roll (described in Japanese Patent No. 116,762). According to Cardiner, the felt passes over the rotating honeycomb roll while conditioning air passes through the porous structure of the rotating roll and the felt. As the honeycomb roll rotates, conditioning air is supplied to a stationary pressurized chamber inside the roll axially from both ends of the honeycomb roll. It is impractical to move the required amount of air through the Y because it requires very high air velocities.The high velocity air loses pressure as it moves through the axial supply pipe, resulting in pressure,
- Temperature and volume will decrease, which will also reduce the adjustability of the felt. Since the maximum pressure of conditioning air is inversely proportional to the radius of curvature of the felt passing over the roll, the felt tension is inversely proportional to the radius of curvature of the felt passing over the roll. It cannot be increased because it cannot be obtained. As a result, honeycomb
In order to increase the roll diameter, it is necessary to lower the pressure of the conditioning air to prevent the felt from floating up from the honeycomb roll surface.

Felt manufacturers recommend a minimum flow rate of conditioning air for a honeycomb roll of approximately 6 cubic feet per minute per square inch of felt, or approximately 25.4 runs per inch of felt width. 2,83
We recommend a minimum air flow of 37 m (10 Dcfm) for approximately 762 cm (300 in) wide felt.
The air volume for adjustment at 0 m/min is approximately 7620 m/min (25, D
OOfpm). When the conditioning air expands through the honeycomb roll under these conditions, its temperature drops to the freezing point of the moisture retained by the felt. Furthermore, as the temperature decreases, the viscosity of the water increases by 1- making removal from the felt impossible.

Further limitations of honeycomb rolls are due to the nature of the honeycomb roll itself. When the moving felt engages the surface of the honeycomb roll, pockets of ambient air are trapped within the cells defined by the honeycomb structure between the felt and the pressurized chamber within the roll. Therefore, the felt conditioning air in the inner chamber of the honeycomb roll is compressed before the trapped ambient air passes through the felt. It must be compressed first. Furthermore, the trapped ambient air will reduce the hot conditioning air temperature. As a result of these constraints, time is wasted and the I effect of conditioning air is diminished. Such air pockets are unlikely to be eliminated since the honeycomb structure requires a certain depth of latticework to obtain sufficient roll strength to maintain the felt under tension. Furthermore, with today's industry trends toward increasing the width of paper machines, honeycomb structures must increase in radius dimension 7 to accommodate strength requirements. Therefore, the honeycomb roll is compressed by pressurized air kefelt'a: II! It is not used commercially in the paper industry because its purpose is to condition the felt by passing it through the paper.

Another felt conditioning device is disclosed in Goumeniouk, US Pat. No. 3,347,740. This device uses a rotating or stationary tube member that supplies air under pressure to fill the pores formed in the moving felt as it expels moisture under the action of centrifugal force. do. Very small diameter tubes or rolls may be required to generate sufficient centrifugal force for water removal. Therefore, for the reasons mentioned above, the method of adjusting felt by using a centrifugal knife or by moving the air through the Y (fell) is a method that cannot be used interchangeably technically, and it is recommended that they be used together effectively. I can't.

Structure of the Invention The present invention provides a method for removing moisture from paper material or cardboard during formation. The present invention relates to a felt conditioning device that supplies air under pressure to the felt for the removal of moisture and trapped substances such as paper fibers, clay, etc. that accumulate in the felt during the removal process.

According to the invention, a stationary air supply pressurized chamber for supplying conditioning air to the felt is arranged on the back side of the felt. The air outlet from the pressurized chamber is fitted with a plurality of supporting ribs which diffuse in conjunction with the back side of the felt which moves in the radial direction vc, i@ the conditioning air passing through the pressurized chamber. It is desirable that the heat (I6) air from a convenient source, such as the final drying section of a paper machine, be compressed and supplied as pressurized conditioning air to the air pressurization chamber.

Vanes are mounted inside the pressurized chamber to direct conditioning air radially toward the felt. In this device, the temperature of the air is only slightly reduced, and the pressure difference before the heated and pressurized air passes through the felt tube to remove moisture can be ignored. The hot air reduces the viscosity of the water, thus facilitating the removal of moisture from the felt.

In a preferred embodiment of the invention, the felt support ribs may be arranged in a "chevron pattern" or at an acute angle to the direction of the paper machine so that the felt spreads out during conditioning.

According to the present invention, the acute supporting ribs have a relatively small radius of curvature, so that in the removal of saturated water, the centrifugal force only assists in this and is of negligible value thereafter. Centrifugal force can be used as an aid in removal.

With continued use, the felt accumulates contaminants that reduce its permeability, thus causing the felt to float away from the support ribs of the air supply pressurized chamber. Avoid the amount of air supplied to the felt? It is necessary to reduce the According to the invention,
Adjust the amount of conditioning air passing through the felt (7) by monitoring the air pressure in the pressurized chamber and the tension in the felt.

One object of the present invention is to ensure that the paper machine operates in a dry state and at relatively high interlocking pressures in the press rolls, so that the amount of moisture absorbed by the felt during each operating cycle is maintained at a relatively high interlocking pressure. The purpose of the present invention is to provide a felt adjusting device for a removing paper machine.

Another object of the invention is to engage the back side of the felt to
To provide a felt adjusting device that does not wear away the fuzz on the paper side.

Another object of the present invention is to provide a felt conditioning system that effectively provides a sufficient amount of heated air to remove moisture and contaminants from the felt.

Another object of the present invention is to provide a filter felt conditioning device for spreading the felt across the machine to facilitate the removal of moisture and contaminants.

Another object of the present invention is to provide an apparatus for adjusting the flow rate of regulating air to a constant pressure in order to maintain a substantially constant felt tension.

Other objectives of the invention will be apparent to those skilled in the art upon practicing the invention, and will be understood from the following description.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention, selected for illustration and explanation of its principles, are shown first in the drawings, and in particular in FIG. An endless felt 18.20 for removing debris, clay, etc. and a cooperating press roll 14.
A press section 10 of a paper machine is shown including an unsupported cardboard strip W passing between 16 and 16. Each felt has a plurality of felt rolls 22 and guide rolls 24
JJ'lE is carried through 26 felt conditioning stations equipped with felt conditioning devices 28 of the present invention. A collection pan 30 collects and discharges moisture and contaminants removed from the felt at each felt conditioning station. 1 felt adjustment device for each press felt
It should be understood that a single unit is not required. Although the felt conditioning stations shown in FIG. 1 are common, these stations can be located at any accessible mobile location. A water tank 29 for flooding the felt is located upstream of each felt conditioning station.

Next, in FIGS. 2 to 5, the felt adjustment device according to the present invention includes a VA wall surface 4, a front wall surface 6. Rear wall surface 6B and end wall surface 40.42'
The air supply header 44, which includes a pressurized chamber 62 in the form of a box-like structure having a Y, is preferably disposed on one of the end walls as shown in FIGS. 2 and 3. For the purpose of directing the conditioning air radially towards the felt and past the fangs 1, air directing vanes 46 are arranged within the space between the front wall 6 and the rear wall 38. If desired, air supply headers 7 can be placed on each end wall of the pressurized chamber, in which case air directing vanes cooperate with each header to deflect conditioning air radially towards the felt. .

As shown in FIGS. 3 to 5, the felt adjustment pressurized chamber includes a plurality of ribs 50 extending along a predetermined radius of curvature from the front wall surface 36 to the rear wall surface 68 of the pressurized chamber. It has an open end defined by. Preferably, the ribs are made from a steel rod having a circular cross section that provides minimal frictional contact with the felt and minimizes the area of the felt that is obscured by the ribs during felt conditioning operations. Each rib is fixed at its front and rear ends 52,53 to the front and rear pressurized chamber walls. A metal shield 54 covers the front and rear ends of the ribs 50. Spaced reinforcing bars 56 maintain the required spacing between adjacent ribs.

To aid in the spreading of the felt during adjustment operations, the support ribs are oriented at an acute angle in the direction of the paper machine and away from the centerline of the machine. Therefore, the felt is
When moved over support ribs angled in the direction indicated by the arrows in the figure, the felt extends cross-machine to open the gap and further increase the efficiency of moisture removal by the conditioning air. do better In order to equalize the airflow to all parts of the felt, the supporting ends 53 of each rib are offset in the cross direction of the machine from its front end 52 by a distance approximately twice its cross-sectional diameter. It is desirable to place the ribs.

This desired positional relationship is best shown in FIG. 5 with arrow A pointing in the direction of the machine and the front end of rib 50 offset from its end 53 by twice the diameter in the cross-machine direction. . This spacing and orientation of the ribs is necessary to obtain an even development area of the felt in the cross direction of the machine.

For the felt conditioning operation, a press felt filled with moisture and contaminants received from the cardboard strip and the felt saturation shower is hung over the open end of the conditioning pressurized chamber. As noted above, the support ribs, which diverge in the direction of felt travel, extend in the cross direction of the felt Y machine to develop the gap to provide a conditioning air purge action. Heated air, preferably obtained from the final drying stage of the machine, is compressed and passed through the air inlet 44 to the pressurized chamber 2.
B and then passed radially through a felt trough to remove moisture and contaminants as indicated by the arrows in FIGS. 3 and 4.

For ease of manufacture, the supporting ribs forming the open end of the air pressurization chamber are slotted into the rolled plate (7a). Supporting ribs formed by notching can be formed from a stainless steel plate rolled to the required radius of curvature.The ribs formed in this way ensure that each rib is in engagement with the moving felt. Its side edges are machined to have curved surfaces. In such a form of the present invention,
The ribs are also divergently oriented such that the leading end of the rib is spaced from the trailing end by twice the effective cross-sectional diameter of the machine.

The outer edge of the open end of the pressurized chamber is provided with a sealing strip that engages the side edges of the felt to prevent air from the pressurized chamber from escaping laterally. Should.

In FIGS. 7 and 8, an open end 86 with a small radius of curvature and a closed end J with a radius of curvature R are shown.
Also shown is a modification of the pressurized chamber 80 having a rear portion 88 and side wall surfaces 82,84 having a generally oval cross-section. With such a pressurized chamber structure, when the felt F moves over the open end, the felt F is connected to the small diameter part so that the tension T of the felt is kept at a minimum value for a certain air direction. 7-Io Therefore, all the advantages of the present invention are that the entire amount of air can be passed through the felt with the force of the felt without the need to increase the tension and breakage of the felt. This is achieved by directing the air to as small a radius as possible to provide six air seals.
8 and 8, the felt is initially small relative to the pressurized chamber at a distance of 24), for example about 5'O, Bmyn(2 In an implementation where it is desirable to initiate contact at a distance of approximately 3 to 12 inches (76.2 to 304.8 mm), the egg-shaped pressurized chamber 80 extends approximately 76.2 to 304.8 mm (3 to 12 inches) along the curvature α between points a and b. ), preferably about 76.2 to 88.9 m
about 50.8 to 127 mm (2 to 5 inches) with an opening of about 76.m (s to 65 inches).
It may have an open end defined by a small radius of curvature from 3 to 6.5 inches. The rear section 88 of the pressurized chamber is approximately 6' to 14 inches to provide a pressurized chamber of sufficient volume to accommodate the amount of air required for purging the felt. It has a large radius of curvature between. Air flow may enter the pressurized chamber through suitable end openings, as in the embodiment of FIG. The outer surface of the side wall is curved to increase rigidity. A plurality of ribs 50 having the same configuration as in FIG. 5 are fitted into the open end of the egg-shaped pressurized chamber. The side wall surfaces 82° 84 of the pressurized chamber are shown in Figures 3 and 11.
It extends across the entire width of the machine. The pressurized chamber is designed to have such a size range.

The fresh air pressure is approximately 0.21 to 0.70 Kq/αn2 (
(0 to 10 psi), preferably about 0.21 to 0.4
9 hcm2 (3 to 7 psi') and a temperature range of about 40 to 12 D'F, the opening 17? ? 'Perhaps felt? The flow rate of the air passing through is approximately 307~1010
98 (/m mark). This air flow range is approximately 508
A permeability of 20 to 120 inches (water column gauge) is sufficient to purge water from the felt. Furthermore, this range of air flow rates and felt purge action is achieved regardless of the operating speed of the machine, which is one of the major advantages of the present invention.

In FIGS. 9 and 10, a seventh chamber is provided with a tapered air supply duct 90 for supplying purge air through an opening 92 extending the entire length of the large end of the pressurized chamber.
Yet another modification of the present invention is shown for constructing the impaction pressurized chamber 80 of FIGS.

The maximum pressure of the conditioning air is a function of the felt tension and the radius of curvature of the conditioning section. At a given radius of curvature, it is necessary to maintain the tension in the felt at some known constant so that the conditioning air has sufficient pressure for effective leaning of the felt. For proper operation, the tension in the felt is greater than the product of the air pressure in the pressurized chamber (pounds per linear inch) times the radius of curvature of the open end of the pressurized chamber (6 inches). When using new felt tra
Fell N4 elongation or creep 2 is likely to occur and therefore it is necessary to take up slack in order to maintain constant felt tension. Hence the change in felt tension? For sensing, an Emery load cell 62 (FIG. 3) or Φ gage is provided on the bearing of the felt roll 22.

This load cell cooperates with a telescoping roll 64 movable via a working diaphragm 66 to restore the required felt tension. As shown in FIG. 3, the loading cell 62 detects the felt tension w and signals the differential pot 6B which compares the signal to a reference value for the felt tension. If the felt tension is lower than the required value,
The differential pot actuates an air valve to introduce compressed air against a diaphragm 66 which moves a slidably mounted telescoping roll 64 to restore the tension in the felt 20 to the desired value. do. Blow valve 72 allows the diaphragm output to be reduced if it is necessary to reduce felt tension in an emergency situation during operation.

Pressed felts typically accumulate a build-up of contaminants during their service life which, if not removed, will result in reduced permeability of the felt to conditioning air. Therefore, as the felt ages, the pressure of a certain amount of conditioning air passing through the felt will increase and try to lift the felt off the supporting ribs, so that the conditioning air is forced into the felt. It escapes from the felt edge without passing through. In such a case, is the same adjustment air pressure? As the felt ages, it becomes necessary to provide a mechanical valve that reduces the amount of air passing through it. As shown in FIG. 3, a field shutter 74 within the air pressurization chamber 28 detects changes in air pressure within the air supply pressurization chamber. The signal of this pressure transducer is.

Compare with the standard value for the air pressure in the pressurized chamber using the differential equation 68. If this signal exceeds a predetermined increment, the differential pot opens and closes the exhaust valve 76 in the pressurized chamber air supply device 7B to change the amount of air entering the pressurized chamber for supplying air at a constant pressure. Thus, if the felt loses its permeability 2, no air pressure will build up within the pressurized chamber.

It will be appreciated that the permeability of the new felt will vary and that the above device can be adjusted to the required values of felt tension and pressurized chamber air pressure.

Functions and Effects The felt conditioner according to the present invention is filled with absorbed moisture and comes out of the meshing part of the press in a state containing impurities picked up from the paper material. As the felt approaches the felt adjustment Stacey 1 yKffj,
Wet the felt thoroughly in the shower to prepare it for purging. The felt is then passed over a pressurized chamber opening for air purging with its back side engaged with a diverging rib to describe a predetermined radius of curvature, and said rib extends the felt to remove moisture. It is also deployed for the purging action of conditioning air to remove impurities.

The pressure of the air in the pressurized chamber is approximately 76 to 680 m of mercury (
6 to 15 inches), approximately 178 inches of mercury.
7 to 8 inches (7 to 8 inches) is desirable. Pressurized, hot air flows radially within the pressurized chamber and past the felt for conditioning. Moisture removal is aided by the centrifugal forces created in the felt as it moves through the conditioning stationer at high speed. With a radius of curvature of approximately 100 ms (4 inches) in the adjustment section, the felt adjustment device offers superior operational advantages over conventional suction boxes with absorption slots approximately 25.4 mm (1 inch) wide. do. This felt conditioning device allows for much more efficient felt purging as the residence time of the felt during the conditioning zone is increased by 10 times.

The device also eliminates the need for expensive vacuum pumps and eliminates the need for vacuum pumps in suction box devices.
[There is no need for 1 ton (I Do, mouth no gallons) of water for stabbing. Tension in the felt is maintained at a constant value by a sliding load cell cooperating with a diaphragm-actuated tension roll to control any creep that may occur in the felt after continuous use. Furthermore.

In order to adjust the gradual loss of permeability as the felt ages, an output monitoring device that detects the formation of air pressure in the pressurized chamber of the conditioning air as the permeability of the felt decreases? When this condition occurs, the flow rate of air into the pressurized chamber decreases, thus providing the maximum adjusting air pressure for a constant felt tension.

From the description hereinafter, the present invention provides a novel and improved method for supplying conditioning air through a papermaking felt for purging the felt so that the felt reaches the meshing part of the press in a dry state. It will be understood that the equipment provided is as follows.

[Brief explanation of the drawing]

Fig. 1 is a schematic illustration of the press section of a paper making machine in which the felt adjusting device of the present invention is incorporated.Figure 5 is a detailed explanation of the felt adjusting device of the present invention incorporated in the press section of a paper machine. FIG. 3 is a front view showing a pressurized chamber for felt conditioning air according to the present invention. Figure 4 (also a sectional view of the pressurized chamber in relation to line 4-4 in Figure 3,
Figure 5 is a partial plan view of the center of the chamber showing the felt supporting ribs; Figure 3 shows the tension of the felt in the paper machine and the air pressure in the horse compartment for regulating air kept approximately constant. FIG. 7 is a partial perspective view showing a modified example of the pressurized chamber according to the present invention, and FIG.
FIG. 9 is a side view showing a modified example of the pressurized chamber according to the present invention, and FIG. 10 is a cross-sectional view showing the IIE chamber, and FIG.
o,,1. It is a sectional view regarding 'o:. 10... Press s+, 14... Breath ψ roll. 16...Press-roll, 18...Endless felt. 20...Endless Fell), 22...Felt・
Row #, 24...Guide roll, 26...
Felt adjustment station, 28°°fel)a
Arrangement fit, 29... Shower, 30... Collection pan, Filter 2... Pressurized chamber, Filter 4... Top wall surface,
Ro6...front wall surface, 6B...rear wall surface, 40...
- End wall surface, 42... End wall surface, 44... Air supply header, 46... Air directing vane. 50...rib, 54...shield, 56...
・Reinforcement bar, 62...Load cell, 64
...Telescopic roll, 66...Diaphragm for operation, 6B...Differential pot, 72...Blowout valve 5
74... Pressure cadence juicer, 76... Exhaust valve, 7B... Air supply device, 80... Pressurized chamber,
82.84... Side wall surface, 86... Opening end,
90...Air supply duct, 92...Opening.

Claims (22)

[Claims] (1) In a device for adjusting the felt of a paper machine having a paper side and a back side, the felt is defined by an upright front wall surface, a rear wall surface, and an end wall surface, and extends over almost the entire width of the felt in the cross direction of the machine. An elongated, stationary, air-supplied pressurized chamber is provided, the pressurized chamber having an open end located in opposing relationship with the back side of the felt, the pressurized chamber being adapted to engage the back side of the felt where adjustment is being performed. A plurality of rib members are provided across the open end between the front wall surface and the end wall surface of the pressurized chamber, and each of the rib members is arranged along a certain radius of curvature with respect to the open end of the pressurized chamber. , the rib members are spaced apart from each other in the cross direction of the machine and extend from the front wall surface to the end wall surface of the pressurized chamber, and the open end of the pressurized chamber communicates with the back side of the felt, so that the rib member defining a plurality of air passages having the same radius of curvature as the ribs and pressurizing the felt along the surface of the felt to allow air to flow from the pressurized chamber through the felt with minimal resistance; a device for sealing the periphery of the open end to prevent air from leaking from the chamber, and a mercury column of approximately 76 to 380 mm to flow through the pressurized chamber approximately in the radial direction of the felt.
To supply conditioning air to the pressurized chamber at a pressure of (3 to 15 inches) and to remove contaminants and moisture from the felt, approximately 307 to 1098
A device for passing the felt through the felt at a flow rate of m^3/min). 2. The apparatus of claim 1, wherein the rib member has a curved surface in the cross-machine direction to engage a minimum surface area on the back side of the felt. (3) The rib member has a chevron shape that diverges in the downstream direction in order to extend the felt and open the pores of the felt.
Apparatus according to claim 1, characterized in that it is arranged in a pattern to improve the effect of conditioning air in removing contaminants and moisture from the felt. (4) The apparatus according to claim 3, wherein the front end of each rib member is offset from the rear end by a distance equal to twice the cross-sectional diameter of the rib in the cross-machine direction. . (5) A movement that has a paper side and a back side and is incorporated into the press section of the paper machine to absorb moisture from the paper material on the paper side when the felt and the long paper material pass through the meshing part of the press. An apparatus for adjusting an endless felt, comprising a pressurized chamber defined by upright wall members joined in an airtight manner, and a device for supplying air under pressure to the pressurized chamber, The pressurized chamber has an open end extending across substantially the entire width of the felt and is spaced apart from the back side of the felt, with one end of the pressurized chamber extending along a common radius of curvature. a plurality of ribs extending across the section and engaging the back side of the felt, the ribs being spaced apart to extend the felt and effect the removal of moisture from the conditioned air; oriented, the rib members are spaced from each other in a cross-machine direction, and extend across an open end of the pressurized chamber, and the open end of the pressurized chamber communicates with the back side of the felt. A plurality of air passages having the same radius of curvature as the ribs are defined in the pressurized chamber to allow air to flow from the pressurized chamber to the felt with minimal resistance due to the ribs. a device for supplying pressurized conditioning air, and directing said conditioning air radially within said pressurized chamber and past the felt so that said felt returns dry to the meshing part of the press; and a device for removing moisture and impurities from the pressurized chamber by sealing the periphery of the open end of the pressurized chamber with felt to prevent air from leaking from the pressurized chamber along the back side of the felt. A device characterized in that it is provided with a device. (6) the air supply device further produces a maximum hydraulic pressure drop of about 3 inches on the conditioning air as it enters and moves across the pressurized chamber; 6. The device according to claim 5, characterized in that: (7) a felt roll for monitoring felt tension;
further comprising a load cell cooperating with the movable telescoping roll for varying felt tension, and a device cooperating with the load cell for moving the telescoping roll so as to maintain constant felt tension. The device according to claim 5, characterized in that: (8) The apparatus according to claim 7, further comprising a device for reducing the flow rate of air passing through the felt at a constant pressure as the permeability of the felt decreases. (9) The pressurized chamber has an oval cross-sectional shape characterized by a small radius of curvature at the open end and a large radius of curvature at the rear end.
Equipment described in Section. (10) the pressurized chamber has a small radius of curvature within the range of approximately 50.8 to 127 mm (2 to 5 inches) at the open end and approximately 152 to 356 mm (6 to 14 inches) at the rear end; Claim 5 characterized by having an oval cross-sectional shape characterized by a large radius of
Equipment described in Section. (11) The pressurized chamber has a small radius of curvature within the range of about 76.2 to 88.9 mm (3 to 3.5 inches) at the open end and about 152 to 356 mm (about 152 to 356 mm) at the rear end.
6. The device of claim 5 having an oval cross-sectional shape characterized by a large radius in the range of 6 to 14 inches. (12) Claim 11, characterized in that the rear end of the pressurized chamber is provided with an elongated opening and a tapered duct for allowing air to flow through the pressurized chamber. Apparatus described in section. (13) The opening is approximately 76.2 to 88.9 mm (3 mm) measured along the curvature α of the pressurized chamber between points a and b.
13. The apparatus of claim 12, wherein the device is within the range of 3.5 inches to 3.5 inches. 14. The apparatus of claim 12, wherein said aperture is within a range of about 3 to 12 inches measured along said radius of curvature. (15) Approximately 50 to guide the felt to be adjusted
．． Pressurized air is supplied to a pressurized chamber having an open end defining a curved surface having a radius of curvature between 8 and 127 mm (2 and 5 inches), and from the pressurized chamber about 4 inches
．． 44-48.89°C (40-120F), approximately 0.
21~0.70Kg/cm^2 (3~10psi)
A sufficient amount of air within the range of the gauge is passed through the open end at a rate of about 7 to 25 cfm per square inch of felt.
A method for adjusting felt for papermaking, comprising the step of supplying felt at a flow rate within the range of . (16) Maintaining a felt tension greater than the product of the air pressure in the pressurized chamber per pound (approximately 0.45 Kg) per inch (approximately 25.4 mm) in a straight line x the radius of curvature of the open end; Claim 15 characterized in that it includes
The method described in section. (17) A method for conditioning a papermaking felt having a back side and a paper side, comprising (7) moving the felt through a radius of curvature defined by the open end of an air pressurized chamber; Approximately 0.20 to 0.71 m^3 per 1 square inch (approximately 645 mm^2) at the open end of
76.2 to 381 mm (3 to 15 inches) of mercury to the pressurized chamber at a flow rate of 7 to 25 cfm.
Pressurized air is supplied within the range of , and this air is sent from the pressurized chamber through the back side of the felt at the above flow rate to adjust the felt, and is sealed against the outer periphery of the open end of the pressurized chamber. and preventing air from leaking from the pressurized chamber along the felt surface. (18) The air in the pressurized chamber is approximately 4.44 to 48.89
18. A method according to claim 17, characterized in that the temperature is in the range of 40 to 120F. (19) The method further includes the step of supporting the felt as it crosses the open end of the pressurized chamber so that the pressurized air flows uniformly to all parts of the felt. Claim 17 or 18
The method described in section. (20) The radius of curvature is about 50.8 to 127 mm (2
19. A method as claimed in claim 17 or claim 18, characterized in that the thickness is within the range of 5 inches to 5 inches. 19. A method as claimed in claim 17 or claim 18, including the step of moving the felt across the open end to effectively purge the felt. (22) Claim 1 further comprising the step of passing air from the back side of the felt to the paper side.
The method described in Section 7.