US2306607A - Web drying method and device - Google Patents

Description

Dec. 29, 1942. H I "2,306,607

I WEB DRYING METHOD- AND DEVI/CBS Filed Dec. 30-, 19:51 4 2 Sheets-Sheet 1 fi t 4 INVE2NTOR. L A L \JZLb enZLI HOr EO f i I a Dec. 29, 1942. A. J. HORTON 2,306,607

WEB DRYING'METHODY AND DEVICES Filed Dec. 50, 1937 2 smug-sheet 2 m'v'zu'roa.

Patented Dec. 29, 1942 UNITED STATES lA'lENT 'oFF'iicE 2,306,607 was name Ms'rnon AND DEVICE Albert J. nei-ien, White Plains, N. in, minor to R. Hoe & 00., Inc., New York, N. Y., a corpora tion of New York Application December 30, 1937, Serial No. 182,594

3 Claims. (01. 34-23) ders and led over aheated drum or subjected to the drying action of .preferably heated air.

When the web is thus heated, its moisture content is greatly reduced thereby resulting in variation in length of the web with the. consequent difiiculty in effecting accurate register during the printing operationsg Furthermore, the lack of requisite moisture in the paper causes it to become roughened and its strength weakened.

Attempts have been made to moisten the web during the drying operation by passing the freshly printed'web through an'enclosure or housing into which aqueous vapor is fed in the form of 2 including an enclosure or duct communicating.

steam jets which impinge heated air circulated in the enclosure or housing about the web. With such method, however, it is difllcult to accurately control the moisture content of the drying air, because an excess quantity of steam raises the percentage of humidity in the drying air to a degree that interferes with the proper drying of the web.

An object, therefore, of this invention is to provide a method of and mechanism for drying a freshly printed web or sheet by subjecting the freshly printed web or sheet to the drying action of heated air to which aqueous vapor is added in accurately controlled quantities to thereby maintain the moisture content of the web substantial- -ly constant throughout the entire web drying operation. 7

Another object of this invention is to providemeans for drying a freshly printed web by passing the web through an enclosure or housing to 40 which heated air. is supplied, and passing the heated air over a receptacle containing water so that the air is thus properly humidified before impinging the web.

A further object of this invention is to provide heated air in passing through the enclosure or duct on its way to the web housing passing over a receptacle-containing water or other suitable liquid in accurately controlled quantity, so that the heated air picks up the requisite quantity of of moisture content in the web-drying air durin the entire web drying operation. 1 I

A specific object of this invention is to provide a web drying device in which a freshly printed web is led through a housing and heated air directed through an enclosure or duct into the housing and circulated therein against the web,

7 the heated air in passing through the duct on its way to the web housing passing over a receptacle or receptacles containing water or other suitable liquid in predetermined quantity, and

the area of water surface exposed to the passing heated air being controllable so that the heated air'picks up the requisite quantity of moisture to maintain a predetermined percentage f moist'ure content in the web-drying air during the drying operation.

A more specific object of this invention is to provide a web drying device in which a freshly printed web is led through a housing, the' device with the housing, a liquid-containing recept cle located within the duct and communicating ith a source of liquid supply, heating means loc ted in the duct in advance of the liquid container to thereby heat air passing through the duct on its ,way to the web housing before this air passes the quantity of liquid supplied to the container, the

container being arranged to expose the liquid to the passing heated air throughout a surface area which isdetermined by the quantity of liquid in the container, so that the heated air in passing the exposed surface of the liquid picks up the requisite quantity of moisture to maintain a determin'ed percentage of moisture content in the durable and inexpensive in construction, as well as convenient, practical and serviceable in. its

use. v p

With the foregoing and other objects in view, which will appear as the description proceeds.

theihvention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood that various changes'in form, proportion, and minor details of construction may be made within the scope of the claims without departing, from the spirit or sacrificing any advantages of the invention.

For a complete disclosure of the invention, a moisture to maintain a determinedpercentage detailed description of it will now be given in with an exhaust Figure 4 is a detail elevation looking in the direction of the arrow 4 in Figure 3 and depicting the adjusting mechanism for the liquid level con-.

trol float, and

Figure 5 is a vertical longitudinal sectional view taken through a modified air conveying and humidifying duct.

Referring to the drawings in which similar reference characters designate corresponding parts, there is depicted a machine frame l0 arranged to support a plurality of printing units H, but, in-

asmuch as these units are similarly constructed,

only one unit is shown in the drawings of this application. Each printing unit includes an intaglio form cylinder l2 and a cooperating impression cylinder l3. The impression cylinder I3 is engaged by spaced rollers M which reinforce it against movement away from the form cylinder l2 during the printing operation. This printing unit is of conventional construction well known to and understood by those skilled in the art, therefore, it is thought that no further disclosure thereof need be made in this application.- I

- A plurality of web guide rollers |5 are provided to guide a web W to the printing unit from another unit or from a suitable web supply, not shown. The web'W is guided from the printing unit H by a plurality of rollers l6 operably supported in a fan casing 34, that, in turn, communicates with an exhaust pipe which may lead to. any preferred destination. Suitably constructed blower type centrifugal fans 36 and 31 are operably disposed in the casings 26 and 34,

respectively, and these fans are rotated by an electric motor- 38 of conventional construction mounted upon a component of the machine frame I0.

'A housing 4| extends downwardly" from the drum and is provided with a front wall 42 and a rear wall 43, the housing being best shown in Figure 1. Between the front and rear walls 42 and 43 spaced partitions 44 and 45 are provided, which, together with the walls 42 and 43 form separate ducts 48, 41 and 48. The duct 46, formed by the front wall 42 and the partition 44, is in communication with a chamber 49 formed within the drum 20 at the exhaust side of the partition 2| through an elongated opening 5| formed in the wall of the drum at the side of the partition 2| which is disposed towards the exhaust conduit 33. The

duct 48 formed by the rear wall 43 and the p'arti 3 disposed towards the intake conduit 25. A wall web drying device H of known construction which is hereinafter described and which is also disclosed in United States Patent No. 2,126,778, granted to Albert J. Horton on August 16, 1938. After the web leaves the web drying device I1, it is guided by rollers I8 to the next printing unit or to the delivery mechanism of the printing machine, but,

inasmuch as such delivery mechanism forms no part .of this invention it has not been depicted in I the drawings of this application.

An improved web drying device is provided which includes a hollow cylindrical drum 28 having a transverse partition 2| therein, as indicated in Figure 2, for a purpose to be hereinafter dis is spaced from and parallels a portion of the wall 42, and this wall and its marginal flanges provide a receptacle. which'houses the web guide rollers l6. ported by a bracket or a component of the machine frame so that the air supply or directing device may be swung on its supporting rollers 22 away from the wall 55 to permit access to the web guide roller l8. Theair receptacle 56 is in communication with the duct 46 through an elongated pas sage 51 which extends substantially across the entire width of the front wall 42 of the housing 4|. The air receptacle 58 is in communication with the I ducts 41 and through similarly formed elonclosed. The opposed terminals of the drum 28 are preferably rotatably supported'uponantifriction rollers22 mounted on brackets 23 forming componentsof the machine frame ID. A stationary intake conduit 25 is connected to one end of the drum 20 and communicates with a fan casing 28 which is, in turn, communicated with an air intake conduit 21. A heating unit is provided and includes a plurality of parallel pipe sections 28 having their adjacent terminals interconnected by U-shaped pipe sections 38, and one terminal pipe 28 of the heating unit is connected with an intake pipe 3|, and the opposed terminal pipe 28 is connected with an outlet pipe 32. The pipe 3| communicates with any suitable source of heated fluid supply, preferably steam, to thereby cause the heating-unit to heat air passing through the conduit 21, as will be hereinafter explained. The pipe 32 may lead back to the source of steam supply or to any suitable exhaust terminal not shown. The other terminal of the drum 28 is connected with an exhaust conduit 33 which communicates gated passages 88 and 58 respectively. This arrangement for supplying air currents to the running web is disclosed in the hereinbefore cited Horton Patent No. 2,126,778.

When it is desired to subject the running web W to the drying" influence of air currents, the fans 38 and 31 are rotated to cause a flow of air from the conduit 21, through the casing 26 and intake conduit 25, into the chamber 53 formed" in the intake end of the-drum 20, and from this chamber 53 through the opening 54, duct 41 and passage 58 to the web W. -The air upon impinging the web spreads and flows in opposed direction over the printed surface of the web' thereby drying the ink by evaporation of the ink solvents. This air is then exhausted from the I receptacle 58 through the passages 51 and 59 into the ducts 48 and 48 respectively, from which it flows through openings 5| and 52 into the chamber 48 formed in the exhaust end of the drum 28, and from there through the conduit 33 and the fan casing 34 into the exhaust pipe 35 through which it is directed to any preferred destination.

The incoming air in passing through the conduit 21 is heated by the coil or pipes 28 and then conveyed, as hereinbefore disclosed, to the running web. It has been found that while heated This wall may be independently suppan or receptacle 8|.

air rapidly dries the web by evaporating the ink solvents, it has F'also been observed that the resultant lowered relative humidity of the web drying air aflects the'length of the web, reduces its strength and roughens its surface. In 'order to increase the moisture content of the web drying air to the requisite degree, the conduit 21 is enlarged, as indicated at 88, for the reception of superposed pans or receptaclesv 81. While two pans 6| have been'depicted as disposed in superposed relation, it is of course to beunderstood An inlet port 68 is provided" for each pan or receptacle 8i, and this port terminates in a frusto-conical valve seat 81 positioned within the A pipe nipple or section 88 is threaded into the. outer terminal of each inlet port 86, and the pipe nipples 68 communicate with a supply pipe 18 through interposedbranch pipes 1l,.the supply pipe 18 leading to any source of liquid supply, preferably water, which supplies the moistening liquid for the pans or receptacles 6|, as will be hereinafter more fully disclosed. A conical valve 121s arranged to operably engage each valve seat 81, and each valve 12 is supported by a valve, stem 18 slidably mounted in-a bearing 1| formed in a bracket 15 having a downwardly extending marginal flange or apron 18 which serves as a-baiiie to direct the water supplied through the inlet port "towards the bottom of the pan or receptacle 8!, as will be more fully explained hereinafter. The upper or outer terminal of each valve stem 18 is operably connected to the bifurcated head 11 of an arm 18 by a pin 88 which extends through the head minal of the sleeve 85 by a screw 88, or other suitable securing device, and the outer terminal of the arm 88 has an adjusting screw 81 threaded therethrough, as best shown in Figures 3 and 4,

which screwis preferably provided with a knurled manipulating head .82. The outer terminal of the shaft 82 has an arm 88 rigidly secured thereturn, heated by steam or other suitable heating fluid thereby raising the temperature of this air. As the heated air passes from the coil or pipes 28 through the conduit 21, it passes over the surfaces of the water or fluid contained in the receptacles 8|, thereby picking up moisture from the exposed water or liquid, and this moisture is then conveyed through the-web housing to the web to sufficiently humidify the web-engaging air to, prevent the heated air from changing the length of the web or to weaken .it or to roughen its surface. The quantity of moisture picked up from the pans or receptacles 8| is determined by the hygrometric state of the heated air, andgthe area of .water surfaces exposed, but, principally by the area of water surface exposed to the passing air.

Inasmuch as each panor recept'acleiil is provided with an inclined bottom, it is manifest that the water height or level within each pan determines the area of water surface exposed to the passing air. When the water level is low, as indicated in the upper pan in Figure 2, a relatively small water surface area is exposed to the air, but, when the water level is raised, as indicated in the lower. pan in Figure 2, a relatively great surface area is exposed to the passing air.

The height of the water level in each pan can be readily adjusted by manipulating the adjusting screw 81' to vary the angular relation between the arms- 88 and 88, which, through the interposed shaft 82 and sleeve 85, control the angular disposition of the float arm 81 relative to the valve arm 18. By adjusting the angular relation between the float arm 81 and the valve arm 18. the valve 12 may be regulated to engage its seat 81 when the fluid head or level has reached a predetermined height. When the valve is opened, as indicated in the upper receptacle in Figure 2, the incoming water impinges the baille "which directs the water towards the bottom of the receptacle to prevent it splashing or flowing from the pan or receptacle GI, and, as-the fluid level reaches a predetermined height the valve 12 is closed, thus shutting of! additional supply of liquid. Thus itisseen that by manipulating the Madiusting screw 82, which is positioned exteriorly in Figure 5, an air-conveying conduit 21 is diato by a key 85, or other suitable securing device,

and the outer or free terminal of the arm 83 is positioned adjacent a terminal of the adjusting with the sleeve 85 through an interposed arm 81, so that up and down movement of the float of the conduit 21, the operator may conveniently control the area of fluid or water surface exposed to the air.

In the modified form of the invention disclosed closed, and the air passes through this conduit on its way to the web housing, as hereinbefore disclosed. A water or fluid receptacle 8i is formed in. the bottom portion of the conduit 21', and suitable heating units or coils 28' are preferably positioned in the receptacle 8| to thereby heat the water or fluid within the receptacle. As the air passes from the atmosphere through the conduit 21', it picks up moisture from the heated water and conveys it to the web housing, as hereinbefore disclosed. In order to vary the amount of moisture picked vup by the air, a, leaf or butterfly valve 88 is operably positioned within the conduit 21', and it has one terminal pivotally secured at the intermediate portion of. the conduit, as indicated at 88. A manipulating handle [88 is 'swiveled or rotatably secured to the wall will oscillate the sleeve for a purpose to be hereinafter disclosed.

In operation, the incoming air passes through the conduit 21, and then into the web housing and engages the web as hereinbefore explained. The incoming'air as it passes through the conduit 21 is heated by the coil or pipes 28, which are, in

of the conduit 21., and a threaded stem iill extends inwardly from the manipulating handle I88. and threadedly engages a nut'lllz carried by the valve 88, so that rotation of the manipulating ,handle I88 will move the valve upwardly and downwardly about its pivotal or fulcrum point 88, as shown in Figure 5 of the drawings.

When a relatively great quantity of moisture is to be conveyed through th conduit 21' to the web housing, the handle IE0 is manipulated to elevate the free terminal I03 of the valve 98 to thus direct a relatively great quantity of air directly over the exposed surface of the body of water in the receptacle 6|. If, however, a lesser quantity of moisture is to be conveyed to the web'housing, the manipulating handle I00 is rotated so that the outer or free terminal.

f I03 of the butterfly valve 98 is moved downwardly, thus directing the desired portion of ,the

air passing through the conduit 21 over the valve 98 and away from the fluid receptacle 6!. From the foregoing it is manifest that the an ular positionof the valve 98 within the conduit 21' determines the quantity of air passing over or impinging the exposed surface of the water body contained in the receptacle 6|, thereby accurately controlling the quantity of aqueous vapor conveyed from the receptacle 6! throug the conduit H to the web housing.

Having thus' described my invention, what I to increase the moisture content of the heated,

air as it passes from the heating unit through the conduitto the web within the enclosure, means for communicating the water receptacle with a source of water supply, a float supported by the water within the receptacle. a valve controlled by the float to control the said water communicating means, and means operably interposed between the float and valve and adjustable from a point outside the conduit to control the height of the water level in the water receptacle.

2. The method of. drying ink oh a freshlyprinted web in multi-stage color printing which consists through an enclosure located between successive printing cylinders, supplying air under pressure through a confined path of travel to the enclosure, heating the-air in the confined path of travel, increasing the moisture content of the heated air in the said confined path by passing the air over and in contact with the exposed surface of a body of water, passing the moistureladen air through the enclosure in contact with the freshly-printed web, and varying the moisture content of the heated air by varying the area of the exposed surface of the body of water.

3. The method of drying ink on a freshlyprinted web in multi-stage color printing which consists in passing the freshly-printed web through an enclosure located between successive printing cylinders, supplying air under pressure through a confined path of travel to the enclosure, increasing the moisture content of the air in the confined path of travel by passing the air over and in contact with the exposed surface ofa heated body or water, passing the moistureladen air from thesaid confined path through the enclosure in contact with the freshly-printed web, and varying the moisture content of the air by varying the quantity of air passing immediately adjacent the exposed surface of the in passing the. freshly-printed webv

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