US2908212A

US2908212A - Vapor confining air curtain for paper machines

Info

Publication number: US2908212A
Application number: US687201A
Authority: US
Inventors: Bryant James Lewthwaite
Original assignee: ROSS ENGINEERING OF CANADA Ltd
Current assignee: ROSS ENGINEERING OF CANADA Ltd
Priority date: 1957-09-30
Filing date: 1957-09-30
Publication date: 1959-10-13
Anticipated expiration: 1976-10-13

Description

Oct. 13, 1959 .1.1.. BRYANT 2,908,212

- VAPOR CONFINING AIR CURTAIN FORPAPER MACHINES Filed sept. so, 1957 v :s sheets-Shana :Tj n IV l R -mH-n `r if A.: '"'i- I 'IFI Q v z vm Sk* I :IJ *.11 I* lil "gL-E. Hi il; y'I

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Il VI IH l .a l Il :,J^ (n I lg ilk gsi En! w il I II I \1 v [Wye/Ifo# RN; James eat/)weite BRYAN/ 7' or,13,'1959 JgLBRYANT v908,21?

VAPOR CONFINING AIR CURTAIN FOR PAPER MACHINES Filed Sept. 30, 195'( 3 Sheets-Sheet 2 Oct. 13, 1959 j J. L, BRYANT 2,908,212 .VAPOR CONFINING AIR' CURTAIN FOR PAPER MACHINES s sheets-sheet s Filed Sept. 30, 1957 [2102922671 y .fa/nes awt/zweite BRYANT l United Sees Patent A, 2,908,212 VAPOR CONFINING AIR CURTAIN FOR PAPER MACHINES James Lewthwaite Bryant, Dorval, Quebec, Canada, assignor to Ross Engineering of Canada Limited, Montreal, Canada, a corporation l Application September 30, 1957, Serial No. 687,201

' 2 claims. (cl. 9s-36) ture and humidity is due to the -fact that under modern day requirements for higher production, higher temperatures have been applied to stock and equipment to raccelerate paper manufacturing processes.

Since machine rooms in a paper mill are quite large it is practically impossible -tocondition the air in the entire room by known air conditioning methods. It is also impossible from a practical viewpoint to conne the equipment by partitioning or shrouding since it is essential that the equipment be readily accessible on all sides.

The present invention aims to provide a solution to this problem by providing means whereby the water vapor and heated air created around the wet end of a paper machine is conned to the room area `about the machine and withdrawn from this area to the exterior of the room without blocking access to the equipment in any way. This is accomplished in accordance with the invention by providing an air curtain formed by jets of supply air which are directed upwards towards a false ceiling provided over .this area of the machine room. The air jets are supplied from a system of nozzle pipes or conduits which are arranged to completely ring the Vapor producing sections of the Pourdrinier including the head box if open, and the screens if an In accordance with the present invention the supply air volume is small and at relatively high pressure and the nozzle pipes are maintained at the smallest practical diameter so as to interfere or obstruct as little as possible with the operation of the machine. 'I'he actual nozzle emitting the air jet can be in the form of aligned rows of relatively small round openings or alternatively can be m-ade as an elongated slot extending the length of a pipe section, whichever proves to be most desirable from a construction viewpoint 'when the system is applied to a particular machine. Preferably the fan or blower supplying the air to the nozzles is located in the machine room and draws the supply air from the interior of the room.

,With the present system the supply volume induces vapor from the Fourdrinier and air Ifrom the machine room in a ratio generally of about 100 parts of induced air to 1 part of supply air and this total volume is exhausted through a corresponding system of ductwork ringing the false ceiling over the Fourdrinier section. 'Ihe 'lower face of the exhaust ductwork ring or header is preferably provided with a slot which is substantially continuous through which the air-vapor mixture is withdrawn from the room. An exhaust fan, located exteriorly j o Y2,908,2'12 lla'tented Oct. 13,

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2-y of the room, for example, `on the machine room roof, is. connected -to the exhaust ductwork to provide the necessary suction eifect.

Having thus generally described the nature of the invention, particular reference will be made to the accom'- panying drawings which illustrate by way of an example an air control system according to the invention as it would appear installed in paper mill 'machine room, and in which:

Figure 1 is a :somewhat diagrammatic View inside elevation and partially in section of an air supply piping system and exhaust ductwork constituting a conning air curtain in accordance with the invention .in operational position yabout the head box, lslice and wet end `of a Fouvdrinier in a paper millmachine room;A j

Figure 2 is -a planlview .of thefarra-ngement-shown in Figure 1,;

Figure 3 is a sectional viewofvFigure 2 lalong the line 3 3. y t j vWith 'reference to the accompanying drawings, an air curtainsystem in accordance with the invention s` shown somewhat d iagrammatically as it would belocated inthe machine room of a paper mill so as to surroundy and confine the moisture vaporv emitting from the wet end of a paper machine. In these drawings, screens A, head box Band Fourdriner C are indicated in broken'lines in their relative locations within the machine roomlA also indicated in broken lines as having side Walls D' and ia roof; structure E. Y t

VIn accordance with the invention, a continuous system of air supply pipes 10 is mounted on,l or supported ad# jacent to, the screens A, head box B 'and the wet end of Ithe -Fourdrinier C so as to ,-form a continuous ring about these portions of the machine. The pipes 10 are provided, in the sections 12, 13, 14, 115, 16 and 17, in the construction shown, with a plurality of openings or nozzles through which airis jetted upwardly and inwardly as indicated by the arrows F towards a yfalse ceiling 20 suspended from the roof structure E. Air is supplied to the piping system 10 by a supply fan or blower 22. `located within the machine room as shown. A system of ductwork 30 is provided which is mounted on and extends about the periphery of the false ceiling 20 with the lower surface of the interconnected ducts being provided with a substantially continuous slot or slots 32 whereby the air vapor mixture directed against the -false ceiling is entraned within the ducts by the action of an exhaust `fan 33 and discharged through an outlet 31. The exhaust -fan 33 and exhaust outlet 31 are preferably located on the machine room roof E as illustrated.

As will be seen, with particular reference to Figure 2 of the drawings, the exhausting ductwork 30 surrounding the wet end of the Fourdrinier is located beyond or outside of the corresponding air supply pipes and the outer marginal edges of the Fourdrinier wire so as to avoid the possibility of any moisture condensation on the ducts from dripping back onto the wire.

This arrangement provides a continuous current or curtain of air rising upwardly and inwardly over the portions of the paper forming equipment whereby the moisture vapor is substantially confined within the area surrounded by the air supply system pipes and entrained with the supply air against the false ceiling 20 where the air vapor mixture is collected and exhausted by the ductwork 30.

As previously mentioned, the supply volume of air forming the curtain as directed upwardly towards the false ceiling 20 will induce vapor emitting from the Wet end portion of the machine. This air, drawn through the fan 22 from the machine generally of the order of one (l) part of supply air to one hundred parts of induced air and this total room in a ratio` `volume @of air-vapor-mixture, is exhausted through the` i l. An ,apparatus-adapted to lconnexmoistureladen Y gases emitting from the Wet end of a paper-making' machine,. to `the immediate arearof 1a jmachine room. containing xsaid 'paper A'machine `wet f endby collection lof gases within saidfroom f-and exhaust ofsa-id gasessi'n -a remote .'.location,-rcomprising inA combination, anv endless air. (supply `conduit system Asurrounding Y-at least. Vthep `n" tions of y said machine emitting 'said' gases, l portions 'oflthe conduit -makingup-A said 'syste1n"'having fair Vemitting openings directed inwardly and upwardly relative to 1- the upper-'surface ofsaid machine, air induction meanshavf ing kan intake disposed within said ,machineroom and being connected to saidconduit system so as to -be adapted to supply airvunderrpressure t' through saidtconduit airfemittng openings whereby a .moving air `cui'-- ta'inisfcreated about the-machine portions sosurroundcd, a false ceiling suspended within said machine vroom above said paper-making area so surroundedand'be'ing adapted to entrap -and deflectsaid curtain. of `.forced-air and v moisture lvapor -entrained thereby, a Ycontinuous ductwork surrounding the outer peripheryM-f-said false ceiling, said :ductwork having air-vapor entr-aiming openings along the length of its lower -surface and terminating in `an ,exhaust portion extending. from said lfalse ceiling, and airwexhausting =means connected-to Vsaid ductwork exhaustportionnand having an exhaust outlet `disposed exteriorly of said-machine-room 2; An apparatus adapted to conne moisture-laden gases emitting from the wet end of apaper-making l machine, to the immediate area of a machine room containing said paperV machine wet end by collection of gases Within said room andeXhaust of said gases ina remote location, comprising V-in ,combination, an yendless air supply conduit 'systemrsur'rounding at least lthe portions of said machine emitting said gases, portions of the conduit making up said system having air-emitting Qpenings directed inwardly and upwardly relative to'jtheupper surface of said machine, air induction means vhaving an intake disposed :within said `machine room andjgbeing connected to said conduit system so as to be adapted to supply air underfpressure'through said conduit air emit- Y ting openings whereby a moving air curtain is created about the machine portions so surrounded, an air deecting and collecting membersuspendedin said-room above ffsaid pape'rmaking-:areaadapted ito entrapfand' deect said curtain of forced air andanyF'moi'stur-eenl trained therebyWair-vapor gentraining meansi adjacent said :fair `fde'flecting member )adapted ltoentr'ain `said {air- 3 vapor mixturezdeflected by=said memrberandlairy eXhausting means toexhaust said entrained mixture exteriorly. of;said"machine.room.

"References Cited in .fthe ile-iof'lthisl patent.V v UNITED STATES `:PATENTS 2,000,546 Woodsome May 1.9135 2,500,606 ,Dosmar Mar. y.-14, 1950 2,565,933 schneible ,Aug. 2s,v19511 v2,567,716 vLundy spt.;11,1951

2,593,702 schneible ApL 22, 19,52 v

FOREIGN-PATE1-ITS Great vBritain Mar.f2`2,19.1`184