System and method for producing mold-resistant paper with wet scrubber assembly

Patent metadata

Field	Value
Publication number	US-10913087-B2
Application number	US-201615248923-A
Country	US
Kind code	B2
Filing date	Aug 26, 2016
Priority date	Oct 5, 2015
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

Embodiments of a system and a method for preparing mold-resistant paper comprising a wet scrubber assembly in fluid communication with at least one collection plenum disposed at an operational area of a paper manufacturing line. The wet scrubber assembly can be operated to draw a stream of exhaust air from the operational area of the paper manufacturing line through the wet scrubber assembly to remove particulate from the exhaust stream. Such systems and methods can be used to produce mold-resistant paper by coating a paper with an antimicrobial composition including at least one antimicrobial additive at the calendering stage. The collection plenum can be placed in proximate relationship with the calendering stack such that the amount of antimicrobial additive particulate in the air at the calendering stage is reduced. The mold-resistant paper can be used in a gypsum panel.

First claim

What is claimed is:

1. A system for preparing paper for a cementitious panel, the system comprising:
a calender stack, the calender stack including a source of an antimicrobial composition, the antimicrobial composition including an antimicrobial additive, the calender stack being adapted to apply a coating of the antimicrobial composition to the paper;
a rewinder, the rewinder disposed within an operational area including particulate-laden air, the rewinder including a cutting roll adapted to cut to a predetermined width the paper having the coating applied thereto, the rewinder including a roll over which the cut paper is positioned by winding the cut paper upon the roll, the particulate-laden air comprising particles produced by cutting the paper at the rewinder station, the particles comprising the antimicrobial additive;
an exhaust collection assembly, the exhaust collection assembly including a rewinder collection plenum disposed at the operational area, the rewinder collection plenum being disposed in proximate relationship to the rewinder, the rewinder collection plenum defining an intake opening, the intake opening being wider than the width of the cut paper;
a wet scrubber assembly, the wet scrubber assembly in fluid communication with the rewinder collection plenum of the exhaust collection assembly, the wet scrubber assembly including a venturi scrubber, a separator, an exhaust fan, a pump, and a supply of fluid, the venturi scrubber being in fluid communication with, and interposed between, the rewinder collection plenum and the separator, the exhaust fan being adapted to draw particulate-laden air from the operational area into the rewinder collection plenum and to direct the particulate-laden air to the venturi scrubber as a flow of particulate-laden air, the venturi scrubber being adapted to receive the flow of particulate-laden air from the operational area via the exhaust collection assembly, the venturi scrubber being in fluid communication with the pump to receive the supply of fluid therefrom, the venturi scrubber being configured such that the flow of particulate-laden air received from the operational area passes through the supply of fluid inside the venturi scrubber to entrain particulate from the flow of particulate-laden air in the supply of fluid and to create a flow of an exhaust/liquid mixture, the venturi scrubber being adapted to direct the flow of the exhaust/liquid mixture to the separator, the separator being adapted to separate liquid with entrained particulate from the exhaust/liquid mixture to produce a cleaned exhaust air stream and a drain flow of liquid with entrained particulate, the separator having an air outlet and a liquid outlet, the air outlet of the separator being in fluid communication with the exhaust fan, the exhaust fan being adapted to draw the cleaned exhaust air stream from the separator via the air outlet toward the exhaust fan, and the separator being configured such that the drain flow of liquid exits from the separator via the liquid outlet.

2. The system according to claim 1 , wherein the rewinder collection plenum is configured such that the rewinder collection plenum is in encircling relationship with at least an arc segment of the roll.

3. The system according to claim 1 ,
wherein the exhaust collection assembly includes a main collection passage, a rewinder trunk, a calender trunk, and a calender collection plenum, the main collection passage being in fluid communication with the venturi scrubber, the rewinder trunk and the calender trunk being in fluid communication with the main collection passage such that the rewinder trunk and the calender trunk are connected in parallel to the main collection passage, the rewinder trunk being in fluid communication with the rewinder collection plenum, the calender trunk being in fluid communication with the calender collection plenum, the calender collection plenum being disposed in proximate relationship to the calender stack;
wherein the exhaust fan is adapted to draw particulate-laden air from the operational area into the calender collection plenum and to direct the particulate-laden air to the venturi scrubber as the flow of particulate-laden air.

4. The system according to claim 1 , wherein the wet scrubber assembly includes a flooded elbow, the flooded elbow being in fluid communication with, and interposed between, the venturi scrubber and the separator, the flooded elbow including an elbow outlet that defines a fluid reservoir within the flooded elbow below the elbow outlet.

5. The system according to claim 1 , wherein the venturi scrubber includes an exhaust inlet, a fluid inlet, a converging section, a throat, and a diverging section:
the exhaust inlet being in fluid communication with the rewinder collection plenum of the exhaust collection assembly to receive the particulate— laden air therefrom, the fluid inlet being in fluid communication with the pump to receive the supply of fluid therefrom, the converging section being in fluid communication with, and interposed between, the exhaust inlet and the throat, the converging section having a converging shape configured such that a transverse cross-sectional converging area defined by an interior converging sidewall of the converging section decreases along an exhaust flow path from the exhaust inlet toward the throat, the throat being in fluid communication with, and interposed between, the converging section and the diverging section, the throat having a cylindrical shape such that a transverse cross-sectional throat area defined by an interior throat sidewall of the throat is substantially circular and substantially the same in the throat along the exhaust flow path from the converging section to the diverging section, and the diverging section being in fluid communication with, and interposed between, the throat and the separator, the diverging section having a diverging shape configured such that a transverse cross-sectional diverging area defined by an interior diverging sidewall of the diverging section increases along the exhaust flow path from the throat toward the separator.

6. The system according to claim 5 , wherein the wet scrubber assembly includes a flooded elbow, the flooded elbow being in fluid communication with, and interposed between, the diverging section of the venturi scrubber and the separator, the flooded elbow including an elbow outlet that defines a fluid reservoir within the flooded elbow below the elbow outlet.

7. The system according to claim 1 , wherein the separator comprises a cyclonic air separator.

8. The system according to claim 1 , wherein the wet scrubber assembly includes an exhaust stack, the exhaust stack in fluid communication with the exhaust fan such that the cleaned exhaust air stream is conveyed from the exhaust fan out through the exhaust stack.

9. The system according to claim 3 , wherein the rewinder collection plenum is configured such that the rewinder collection plenum is in encircling relationship with at least an arc segment of the roll.

Assignees

• United States Gypsum Co

Inventors

• Hajakian Paula

Classifications

• B01D47/10 Primary

  Venturi scrubbers · CPC title

• B01D2247/105

  by gas flow reversal · CPC title

• B01D2247/14

  Fan arrangements for providing induced draft · CPC title

• B01D2247/08

  Means for controlling the separation process · CPC title

• D21F11/00

  Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines · CPC title