US 6,306,258 B1Granted

Air press

AssigneesMetso Paper, Inc., Mitsubishi Heavy Industries, Ltd., Kimberly-Clark Worldwide, Inc.

InventorsDavid V. Lange, Roger A. Kanitz, Richard D. Hauser, Patrick W. Murry, Doug A. Rounds, Robert L. Clarke, Frank S. Hada, Michael A. Hermans, Charles R. Tomsovic

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Abstract

A pressurized box is positioned opposite a vacuum box. The pressurized box has a leading cross machine direction baffle with a ceramic shoe which engages a forming fabric, and a trailing cross machine direction baffle of similar construction. Two end deckles complete the pressurized box. The leading cross machine direction baffle presses against a resilient seal which causes a web contained between upper and lower forming fabrics to wrap about the baffle shoe a few degrees forming an effective end seal which does not allow air to bypass the baffle. The trailing cross machine direction baffle is positioned over a vacuum box which prevents air from leaking around the trailing baffle. A vacuum box draws air through the forming fabrics and the web, from the pressurized box increasing the total pressure gradient across the web to 20 to 30 psi or more. The pressure box and opposed vacuum box form an air press. The pressure box is positioned and held against the forming fabrics by opposing air tubes. An alternative embodiment utilizes a suction roll positioned beneath the pressure box and having a suction gland positioned beneath the portion of the roll which backs the pressure box.

Claims17

Dependent claims

An apparatus for removing water from a web formed of fibers comprising:

a first forming fabric which is permeable to air;
a second forming fabric which is permeable to air;
a web of fibers containing between about ten and about forty percent fibers dry weight and about ninety to about sixty percent water, the web being positioned and held between the first forming fabric and the second forming fabric;
a first box rigidly mounted with respect to the first forming fabric and connected to a source of pressurized air;
a plurality of baffles extending between the box and the first forming fabric and defining an area of the first forming fabric, the plurality of baffles extending into the first box so as to seal the source of pressurized air to the area of the first forming fabric, the baffles being substantially devoid of surfaces on which pressure in the first box acts in a way to force the baffles towards or against the first forming fabric;
a seal formed between the plurality of baffles and the first box so that air supplied to the first box is substantially constrained to flow through the first forming fabric, the web of fibers and the second forming fabric;
a means for urging each of the baffles towards the first forming fabric;
and
a means for drawing a vacuum positioned adjacent to the second forming fabric, the vacuum means engaging the second forming fabric over an area which at least encompasses substantially all of an area opposite the area of the first forming fabric which is sealed to the source of pressurized air;
wherein the vacuum means comprises a vacuum box with a plurality of cross machine direction forming fabric supports, at least two of said cross machine direction forming fabric supports defining a pocket into which the first forming fabric and second forming fabric and web are urged by at least one of said plurality of baffles overlying the first forming fabric, the pocket defining a seal, and wherein the pocket is filled with a resilient material and underlain by a rigid support.

7 more elements

An apparatus for removing water from a web formed of fibers and held between opposed forming fabrics, the apparatus comprising:

a first forming fabric which is permeable to air;
a second forming fabric which is permeable to air;
a first box fixed with respect to the first forming fabric and connected to a source of pressurized air;
a plurality of baffles extending between the box and the first forming fabric and defining a first area of the first forming fabric, the plurality of baffles extending into the first box to seal the source of pressurized air to the first area of the first forming fabric;
a seal formed between the plurality of baffles and the first box so that air supplied to the first box is substantially constrained to flow through the first forming fabric, the web of fibers and the second forming fabric, wherein the plurality of baffles are positioned in the first box and sealed to the first box by the seals so that air pressure in the first box does not act on the baffles to urge the baffles towards or away from the forming fabric;
an actuator extending between each baffle of the plurality of baffles and the first box to move the baffles towards and away from the first forming fabric;
and
a structure positioned adjacent to a second area defined on the second forming fabric, the structure drawing a vacuum on the second forming fabric over the second area which at least encompasses substantially all of an area opposite the first area of the first forming fabric which is sealed to the source of pressurized air, wherein the structure positioned adjacent to the second area on the second forming fabric is a vacuum box with a plurality of cross machine direction forming fabric supports, at least two of said cross machine direction forming fabric supports defining a pocket into which the first forming fabric and second forming fabric are urged by at least one of said plurality of baffles overlying the first forming fabric, the pocket defining a seal, and wherein the pocket is filled with a resilient material and underlain by a rigid support.

5 more elements

Dependencies are inferred from the claim text.