US2714839A - Apparatus for extracting water from paper stock - Google Patents

Description

J. MAZER Aug. 9, 1955 APPARATUS FOR EXTRACTING WATER FROM PAPER STOCK Filed Feb. 28, 1951 INVENTOR f /C05 MAZEQ TTOR VE) United States Patent APPARATUS FOR EXTRACTING WATER FROM PAPER STOCK Jacob Mazer, Rockville Centre, N. Y.

Application FebruaryZS, 1951, Serial No. 213,119

14 Claims. (Cl. 92 -51) This invention relates to paper manufacture and, more particularly, to an improved method of, and apparatus for, morerapidly and more efficiently extracting water from the stock carried on the wire in the form of a pulp web.

Inpaper making machines presently in use, once the stock is deposited on the wire as a pulp web of high water content, successive water removal or drying steps are applied, in addition to the normal water drainage through the wire as the pulp web progresses through the machine. In one type thereof, suction is applied as the wire carrying the pulp web passes a series of spaced fiat suction boxes, and this is followed by successive mechanical or squeeze pressures applied at the couch roll and thereafter, the press roll series. In another type thereof, suction is applied as the wire carrying the pulpweb passes a series of spaced flat suction boxes, and this is followed by the further application of suction atthe suction box I in an extractor drum or suction couch, after which mechanical pressure is applied at the press roll series.

The invention method and apparatus herein involved are directed to improvements in the application of suction applied to the pulp Web on the wire as it passes the suction boxes, so that a greater amount of water may be extracted from the pulp at the respective suction boxes, whether fiat or in a roller drum.

In the present type of rotary extractor drum or suction 1 couch, known to the trade as the Millspaugh type, the

shell of the drum or couch over which the 0 wire carrying thelpulpaweb passes, is perforated, and suction mechanically developed by external pumps is applied to: the stock in the pulp web through a suction box rigidly mounted against rotation within the drum or couch, the suction.

box being essentially of the confonnation of a trough,

the sidewalls of which are in sealing engagementwiththe interior and end walls of the shell of the drum. orcouchw to subtend an arc area defining an arcuate zoneof up.-

aforementioned may vary from 2% to dependent upon the variable factors. above mentioned, but with medium Weight stock and the standard external suction pump above referred to, is about 5%, i. e. the stock at the entry of the pulp web'to the suction zone is about bone dry and at the exit thereof fromthe suction zone isabout bone dry.

In the present type offlat suction box arrangement at the wet end of the paper making machine, thehorizontal planar surface of the box over which the wire carrying thepulp webpasses, is perforated and suction mechani- 2,714,839 Patented Aug. 9, 1955 "ice cally developed by external suction pumps is applied to the stock passing thereover, the amount of vacuum developed in the suction box being on the order of 8" to 16" Hg, dependent upon the thickness of the sheet, the

freeness of the fibres and the size of the suction pump used, and the amount of extraction of water from the stock in the pulp web passing over the area defining the planar. suction zone aforementioned being relatively small for each such box for medium weight stock and the standard external pump used in the industry, a plurality of such suction boxes being arranged in spaced series so that the pulp web by the time it passes the last of the suction boxes is usually about 15% bone dry.

The action at the suction box, whether in the drum or roll or in the spaced flat type, involves a drawing in of air through the pulp web and the perforations on the surface of the box over which the wire passes, with the result that a mixture of air, water and Water and entrained air is drawn into the suction line.

While various attempts have been made to increase the amount of water extracted from the stock by the suction boxes, whether in the suction couch roll or an extractor drum of the character aforesaid, or of the fiat type, the same have not been successful because of the high cost of mechanical equipment and power for developing the higher degree of vacuum requisite for such purpose.

In accordance with the present invention, the water extraction from the. stock at the suction couch roll or extractor drum. and/or the flat suction boxes, is very substantially increased in an. inexpensive manner and without requiring any increase of the amount or size of the mechanical equipment or power consumption, the method and apparatus of the invention being applied to a standard suction couch roll or extractor drum and/ or a standard flat suction box modified as hereinafter outlined.

In accordance with the present invention, steam is discharged on the stock in the form of the pulp Web carried on the wire in a substantially enclosed area along a zone directly above the subtended perforated arc area of the suction box mounted in the extractor drum or couch roll and/or the perforated horizontal planar surface area of the flat suction boxes over which the pulp Web passes,

so that as the steam impinges against the surface and penetrates throughthe interstices of the pulp web in the aforesaid zone thereof, the same is drawn through the perforations and into the suction box by the vacuum maintained therein by the pumps. Such steam, in its movement, upon contact with the pulp web, raises the temperature of the water in the pulp web through heat exchange, whereby a small part of the steam condenses and the remaining steam, as it passes through the pulp web, is mixed and entrained with the water thereof, so that as both water and steam pass into the suction box under the influence of the mechanical suction, further condensation of the steam takes place, with the result that a vacuum, which is independent of, and additive to, the mechanical. suction of the pumps, is developed in the suction box.

By virtue of the condensation of steam aforesaid, there is established within the suction box a degree of vacuum considerably greater than that developed by the external.

mechanical pumps and, consequently, since this is translated into a greater suction effect upon the stock of the pulpweb at the suction zone in the subtended arc area or planar surface aforesaid, a greater extraction of water is attained.

Ina further embodiment of this invention, instead of relying solely upon the extracted Water from the pulp webmixed and entrained with the discharged steam in the suction zone as the mediumfor condensing the steam and thereby increasing the vacuum in the suction box, this invention contemplates the provision within the suction box of a cooling spray of water which, acting on the steam mixed and entrained with the water as it enters into the suction box, serves to condense the steam in the manner of a jet condenser. In this embodiment, a vacuum in excess of 20" Hg may be attained within the suction box and consequently, the amount of extraction of water from the stock in the pulp web may be greatly increased.

Wherever the expression paper is herein applied, it is to be understood that the Same includes pulp, board or other fibrous material in the form of aweb of stock carried on a wire and subjected to Water extraction.

For an understanding of the invention principles, reference is made to the following description of typical embodiments thereof illustrated schematically in the accompanying drawing, in which:

Fig. 1 is a partial diametric sectional view of an extractor drum in the form of a suction couch roll arrangement, embodying the structure and illustrating the method of the invention; and

Fig. 2 is a partial diametric sectional view of a flat suction box arrangement, embodying the structure and illustrating the method of the invention.

Referring to the drawing, and particularly to Fig. l, the Wire coming from the apron or forming roll (not shown), as the case may he, carries a web of paper stock over a longitudinally spaced series of suction boxes (not shown in this embodiment) and in its movement in the direction of the arrow from the right of the drawing, is trained over the rotating extractor drum or suction couch roll 20.

The suction couch roll has formed along the surface of its cylindrical shell 21 a series of perforations 22, which perforations may be in angular spaced relation so as to provide a zig-zag formation, said perforations being spaced sufficiently close to each other so that the peripheral surface thereof is substantially reticulated. The pulp web 15 of stock entering from the right of the drum or roll 20 is approximately 15% bone dry as a result of drainage through the wire and the action of the suction boxes in advance of said drum or roll 20.

The rotating extractor drum or suction couch roll 20 has mounted interiorly of the shell thereof, for maintenance in fixed angular and non-movable relation thereto, a suction box 25 of trough-shape configuration, the sidewalls 26, 26 defining the walls extending axially of the drum or roll 20 to subtend an arcuate area or zone 23 hereinafter called the suction zone of the couch roll. The edges of the sidewalls 26, 26 and the end walls (not shown) of the suction box 25 mount packing members 27, which engage the inner face of the shell 21 to form a substantially airtight seal therewith, the packing mem bers 27 being firmly held against the shell for defining the suction zone 23, by the action of springs 28, which press against the bottom wall 29 of suction box 25.

An external vacuum pump unit (not shown) is connected in the usual manner to the interior of suction box 25 and in connection with the formation of medium weight stock, develops and maintains within the suction box a vacuum in the range of about 12" Hg, as a result of which the stock of the pulp web 15 carried on the wire as it passes the furthermost or left edge of the suction zone 23, is about 20% bone dry.

The structure of the apparatus described to this point is that of the known prior art, and the structure from this point on to be described involves the apparatus which, when applied in accordance with the novel method of the invention, produces the increased extraction of water from the pulp web at the extractor drum or suction couch roll.

In accordance with the present invention, there is mounted above the extractor drum or suction couch roll 29, and axially of the suction box 25, a steam discharge unit which comprises a steam pipe 30, having arcuate deflector shields 31, which may be welded to or formed integral with said steam pipe, said steam pipe and deflector shields being of length co-extensive with that of the extractor drum or couch roll. The free edges of the deflector shields extend to encompass or supertend a steam arc area or zone 24, slightly less in width than the arcuate area or suction zone 23 subtended by the suction box 25, the aforesaid free edges extending radially a slight distance from the upper surface of the pulp web 15, and laterally the distance of one perforation from the edges of the subtended suction zone, so that an air seal is formed between the inner edges of the packing members 27 of the suction box 25 and the outer edges of the deflector shields 31, whereby air drawn into the suction box at the outer edges of the deflector shields and passing between the free edges thereof and the pulp web, prevents the escape into the atmosphere of steam discharged from the steam pipe 36, and effectively provides a steam chest discharging only into the supertended steam zone. The steam pipe 30 has formed therealong two series of spaced angularly directed discharge apertures 33, 33, so that steam issuing therefrom is angularly directed against the inner surfaces of deflector shields 31 and as so defiected, impinges in relatively evenly distributed volume along the entire surface of the pulp web 15, passing through the steam zone" 24, the representative angular movement of the steam being indicated by lines 34.

Within suction box 25 and extending axially of the extractor drum or roll 20, there is provided a water discharge pipe 35 having two angularly disposed series of spaced orifices 36, the orifices being in the form of perforations defining a spray nozzle through which water from the cold Water supply line may be discharged as a spray 37 preferably (although not necessarily) upwardly and radially toward the sidewalls 26, 26' of the suction box 25 for deflection. The water discharge pipe 35 is preferably (although not necessarily) mounted within and extending axially of vacuum pump conduit 38 leading from an end of the suction box to the vacuum pump.

In one embodiment of the invention, the steam discharge assembly alone is applied in connection with the suction box 25 of the extractor drum or couch roll 20, while in the other embodiment of the invention there is additionally applied the cold water spray 37.

Referring particularly to Fig. 2, wherein is illustrated a flat suction box being one of a spaced series disposed in advance of the extractor drum or couch roll and in connection with which like numbers are applied to elements identical with those disclosed in the embodiment of Fig. 1, the wire 15 coming from the apron or forming roll (not shown), as the case may he, carries, in the direction of the arrow, a web 15 of paper stock over the planar top surface 21 of suction box 25.

The suction box is of a standard rectangular type, the top surface of which has perforations 22, which are preferably in zig-zag formation, such top surface 21 being made of wood or metal as the case may be, and being fixedly mounted on and to the sidewalls 26, 26' forming the trough of the suction box, as by bolting and joint sealing. Directly above the planar surface 21 aforesaid of the suction box, there is disposed axially thereof a steam discharge unit which comprises a steam pipe 30 having arcuate deflector shields 31, which may be welded to or formed integral with said steam pipe, the length of the steam pipe and deflector shields being of a length co-extensive with that of the planar surface of the suction box, and the free edges of the deflector shields extending to encompass or supertend a steam area or zone 24 slightly less in width than the subtended area 23 of the planar surface subtended by the walls of the suction box, the aforesaid free edges of the deflector shields extending a slight distance from the upper surface of the pulp web 15 and laterally the distance of one perforation from the edges of the subtended area I 23, so that an air seal is formed between the trough walls of the suction box and the outer edges of the deflector shields, whereby air drawn in by the suction box at the outer edges of the deflector shields and passing between.

the free edges thereof and the pulp web, prevents the escape into the atmosphere of steam discharged fromthe steam pipe and effectively provides a steam chest discharging only into the supertended steam zone.

Within the suction box 25 and extending axially thereof there is provided a water discharge pipe 35 having two angularly disposed series of spaced orifices 36, the orifices being in the form of perforations defining a spray nozzle through which water from the cold water supply line may be discharged as a spray, preferably (although not necessarily) upwardly and radially toward the sidewalls 26, 26 of the suction box 25' for deflection, said water discharge pipe being preferably (although not necessarily) mounted within and extending axially of the vacuum pump conduit 38 leading from one end of the suction box 25 to the vacuum box.

In operation, in accordance with the first embodiment of this invention illustrated in Fig. l, as steam is discharged from steam pipe 30 into the steam zone 24, the saturated steam, upon contacting with the pulp Web 15, heats up the water therein through heat exchange (with resultant condensation of part of the steam) and, under the influence of the mechanical suction at the suction box 25, effective at the suction zone 23,.the steam passes through the interstices of the pulp Web 15 and as mixed, and while entrained with the water of the pulp web, is drawn through the perforations of the shell into the trough of the suction box; the steam, during such passage, becoming condensed as it moves toward the outlet of the suction box, such condensation causing the development of a vacuum in the suction box, independent of the mechanical vacuum maintained by the external pump aforesaid and additive thereto, whereby as a result of such increased vacuum in the suction box, a greater amount of water extraction of the pulp web passing the suction zone is eifectuated. In accordance with this embodiment, the suction, as additively increased, may in connection with medium weight stock, attain a value of approximately 15" to 16 Hg, and the amount of extraction of water is increased, so that at the leaving end of the couch roll, pulp of this character may be from 23% to 25% bone dry.

In accordance with the second embodiment of this invention illustrated in Fig. 1, involving the utilization of the cold water spray 37 within the suction box 25, the steam discharged into the supertended arc defining steam zone 24 performs in the same manner as that outlined in connection with the first embodiment, except that by virtue of the utilization of the cold water spray, the steam entering into the suction box, mixed and entrained with Water, is subjected to a more rapid and more complete condensing effect in the nature of a jet condenser effect, with the result that a much higher vacuum is attained within the suction box and a much greater extraction of water from the pulp web is elfectuated. The vacuum developed in accordance with this second embodiment is in excess of 20 Hg, the only limitation on the approach of the vacuum to be developed in the suction box 25 being that involving the necessity of preventing resistance to the movement of the paper pulp on the wire, the amount of water extraction developed at the vacuum within the range of 20 Hg being from 25% to 28% bone dry.

No detailed description of operation is given with respect to the embodiments of this invention illustrated in Fig. 2 and involving the flat suction boxes, since the operative association of the elements and their functions are identical with those outlined in relation to the embodiments of Fig. 1.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles thereof, it should be understood that the invention may be otherwise embodied without departing from such principles.

6 What is claimed is: 1. In a paper making apparatus of the type inwhich a Web of relatively wet stock supported on a wire is. carried in operative relation over the perforated surface of apump operated suction box to extract water from the .web passing thereover, the combination. therewith comprising means for discharging such steam into contact only with that portion of the pulp web passing over said perforated surface whereby the steam, as it is drawn through the pulp web and the perforated surface and into the suction box by the vacuum maintained therein by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat 'exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump, and accelerating the extraction of water from the pulp web, and means independent of said steam discharging means operable to discharge a spray of relatively cold water from within the suction box into the path of the mixed and entrained steam to amplify the steam condensing action and increase the effective vacuum in the suction box.

2. In a paper making apparatus of the typeinwhich a Web of relatively wet stock supported on a wire is carried in operative relation over the perforated surface of a pump operated suction box to extract water from the web passing thereover, the combination therewith comprising a steamdischargepipe extending axially and above said perforated surface, and axially disposed deflectors extending from both sides of said pipe toward the web, said steam discharge pipe having a series of angular perforation arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the aforesaidperforated surface, whereby the steam, as it is drawn through the pulp web and the perforated surface and into the suction box by the vacuum maintained therein by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to thatof the pump and accelerating the extraction of water from the pulp web.

3. In a paper making apparatus of the type in which a Web of relatively wetstock supported one wire is carried in operative relation over the perforated surface of a pump operated suction box to extract water from the web passing thereover, the combination therewith comprising a steam discharge pipe extending axially and above said perforated surface, axially disposed deflectors extending from bothsides of said pipe toward the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the aforesaid perforated surface, whereby the steam, as it is drawn through the pulp web and the perforated surface and into the suction box by the vacuum maintained therein by the pump, intermixes and is entrained with the water of said web and becomes cendensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web, and means operable to discharge of spray of relatively cold water into the suction box to amplify the steam condensing action and increase the effective vacuum in the suction box.

4. In a paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated surface of a pump operated suction box to extract water from the web passing thereover, the combination therewith comprising a steam discharge pipe extending axially and above said perforated surface, and axially disposed deflectors extending from both sides of said pipe toward the: web and supertending a surface area of less width than that subtended by the suction box to provide air seals between the edges of the deflectors and the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only onthat portion of the pulp web passing over the perforated surface, whereby the steam, as it is drawn through the pulp web and the perforated surface and into the suction box by the vacuum maintained therein by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web.

5. In a paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated surface of a pump operated suction box to extract water from the web passing thereover, the combination therewith comprising a steam discharge pipe extending axially and above said perforated surface, axially disposed deflectors extending from both sides of said pipe toward the web and supertending a surface area of less width than that subtended by the suction box to provide air seals between the edges of the deflectors and the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the perforated surface, whereby the steam, as it is drawn through the pulp web and the perforated surface and into the suction box by the vacuum maintained therein by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of Water from the pulp web, and means operable to discharge a spray of relatively cold Water into the suction box to amplify thesteam condensing action and increase the effective vacuum in the suction box.

6. In paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drurn having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the Web passing over such arcuate area, the combination therewith comprising means for discharging such steam into contact only with that portion of the pulp web passing over said arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum 1,

additive to that of the pump and accelerating the extraction of water from the pulp web, and means independent of said steam discharging means operable to discharge a spray of relatively cold water from within the suction box into the path of the mixed and entrained steam to amplify the steam condensing action and increase the effective vacuum in the suction box.

7. In paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drum having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the web passing over such arcuate area, the combination therewith comprising a steam discharge pipe extending axially of the arcuate area of said drum and having perforations arranged to discharge steam only along that portion of the web passing over such arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web, and means independent of said steam discharging means (.3 operable to discharge a spray of relatively cold Water from within the suction box into the path of the mixed and entrained steam to amplify the steam condensing action and increase the effective vacuum in the suction box.

8. in paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drum having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the web passing over such arcuate area, the combination therewith comprising a steam discharge pipe extending axially of said arcuate area exteriorly of the drum and axially disposed deflectors extending from both sides of said pipe toward the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of Water from the pulp web.

9. In paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drum having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the web passing over such arcuate area, the combination therewith comprising a steam discharge pipe extending axially of said arcuate area exteriorly of the drum and axially disposed deflectors extending from both sides of said pipe toward the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web, and means operable to discharge a spray of relatively cold water into the suction box to amplify the steam condensing action and increase the effective vacuum in the suction box.

10. In paper making apparatus of the type in which a Web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drum having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the web passing over such arcuate area, the combination therewith comprising a steam discharge pipe extending axially of said arcuate area exteriorly of the drum and axially disposed deflectors extending from both sides of said pipe toward the web and supertending an arcuate area of less width than that subtended by the suction box, to provide air seals between the edges of the deflectors and the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web.

11. In paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drum having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the web passing over such arcuate area, the combination therewith comprising a steam discharge pipe extending axially of said arcuate area exteriorly of the drum and axially disposed deflectors extending from both sides of said pipe toward the web and supertending an arcuate area of less width than that subtended by the suction box, to provide air seals between the edges of the deflectors and the web said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web, and means operable to discharge a spray of relatively cold water into the suction box to amplify the steam condensing action and increase the effective vacuum in the suction box.

12. In paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated shell of an extractor drum having a pump operated suction box subtending an arcuate area of the inner surface of the shell to extract water from the web passing over such arcuate area, the combination therewith comprising a steam dis charge pipe extending axially of said arcuate area exteriorly of the drum and axially disposed deflectors extending from both sides of said pipe toward the web and supertending an arcuate area of less width than that subtended by the suction box, to provide air seals between the edges of the deflectors and the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the arcuate area, whereby the steam, as it is drawn through the pulp web and shell perforations by the vacuum in the suction box maintained by the pump, intermixes and is entrained with the Water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web, and means operable to discharge a spray of relatively cold water into the suction box to amplify the steam condensing action and increase the eflective vacuum in the suction box, said spray discharge means comprising a pipe extending axially through said suction box and having a series of spaced angularly directed perforations for discharging the spray upwardly into the path of movement of the steam and water being drawn into the suction box.

13. In a paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated planar surface of a pump operated suction box to extract water from the web passing thereover, the combination therewith comprising a steam discharge pipe extending axially and above said planar perforated surface, and axially disposed deflectors extending from both sides of said pipe toward the web and supertending a surface area of less width than that subtended by the suction box to provide air seals between the edges of the deflectors and the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the aforesaid perforated surface, whereby the steam, as it is drawn through the pulp web and the aforesaid perforated surface and into the suction box by the vacuum maintained therein by the pump, inter mixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web.

14. In a paper making apparatus of the type in which a web of relatively wet stock supported on a wire is carried in operative relation over the perforated planar surface of a pump operated suction box to extract water from the web passing thereover, the combination therewith comprising a steam discharge pipe extending axially and above said planar perforated surface, and axially disposed deflectors extending from both sides of said pipe toward the web and supertending a surface area of less width than that subtended by the suction box to provide air seals between the edges of the deflectors and the web, said steam discharge pipe having a series of angular perforations arranged to discharge steam against the deflectors for deflection thereof only on that portion of the pulp web passing over the aforesaid perforated surface, whereby the steam, as it is drawn through the pulp web and the aforesaid perforated surface and into the suction box by the vacuum maintained therein by the pump, intermixes and is entrained with the water of said web and becomes condensed through heat exchange therewith, thereby developing in the suction box a vacuum additive to that of the pump and accelerating the extraction of water from the pulp web, and means operable to discharge a spray of relatively cold water into the suction box to amplify the steam condensing action and increase the effective vacuum in the suction box.

References Cited in the file of this patent UNITED STATES PATENTS 1,307,750 Perry June 24, 1919 1,438,286 Ayers Dec. 12, 1922 1,501,179 Peacock et al. July 15, 1924 1,550,304 Dolan Aug. 18, 1925 1,560,331 Ayers Nov. 3, 1925 1,718,573 Millspaugh June 25, 1929 1,722,503 Millspaugh July 30, 1929 1,737,781 Ware Dec. 3, 1929 1,767,889 Jurgensen June 24, 1930 FOREIGN PATENTS 246,048 Great Britain Jan. 21, 1926 565,575 Great Britain Nov. 16, 1944

Images