US1694349A - Apparatus for controlling the drying operation in paper machines - Google Patents

Description

Dec. 4, 1928. 1,694,349

' G. S. WITHAM, JR

APPARATUS FOR CONTROLLING THE DRYING OPERATION 1N PAPER MACHINES Filed April 2, 1928 INVENTOR s. BY 5 2L Patented Dec. 4, 1928. i i

arssr'rr are,

GEORGE S. WITHAM, JR, OF HUDSON FALLSL'REW YORK.

APPARATUS FOR CONTROLLING THE DRYING OPERATION IN P APER MACHINES.

Application filed April 2, 1928. Serial No: 266,777. r

This invention relates to apparatus for ordinarily a large gap. In order to close controlling the drying operation in paper this gap, a sealing member 16 of any suitmachines and more in particular to apparaable flexible material is attached to the doctus for controlling the moisture content of tor 14 along its whole upper edge and so 60" the paper at a certain stage of its manufacdisposed as to ride against the felt roll,13,'

t as indicated. Vhile there are many mate- 'The in vention is closely related to appararials available for the purpose of sealing the tus of the type disclosed in my- Patents gap, I prefer at. present rubber belting or. 1,626,060,1,646,515 and 1,646,516 and has for the like. 65-

its general object a simplification of struc- To carry out the object of theinvention,

t air is blowninto the collector space-referred For a full understanding of the invention, to, to thereby take up the moisture given off reference is made to the accompanying drawby the paper and the moisture-charged air i h i is then passed" to a moisture-responsive de- 70 Fig. 1 is a fragmentary side view of apvice As indicated in dotted lines inFig. 3, paratus embodying the invention; a I an 1s preferably prepared or conditioned in Fig. 2 is an enlarged view of parts shown a conditioning' apparatus 17 and then passed in Fig. 1; I by a blower 23 or the like into the space men- I Fig. 3 is a sectional view taken on line tioned. With the nozzle 18 is preferably asso- 20 3 3, Fig, 2, ciated aboard 19 for roughly sealing the Having reference to Fig. 1, 10 are the dryspace adjacent to the nozzle against influx ing rolls of a typical installation consisting of air from the body of-air surrounding the of two or more'rows of drying drums or cyl machine. It is not practically possible and inders in super position. The web 11 of the not necessary to entirely close off cornmuni 80 paper is carried around the drying .cyllncation between the collector space and the ders 10 in the usual way and the felt roll outside, leakage of air into the collector space 1-2 with the-felt 13 passing over the drying being avoided by producing a sufiicient posicylinders in superposition on the web ofpative pressure at the nozzle end? per also constitutes part of a usual form of Into. the end of the collector space oppo- 85 36 paper machines. I j site to the nozzle 18, I place a. pipe 21 for In the space between the drying cylinpassing a sampling stream of the moistureders 10, below the felt roll 13 is disposed a charged air to a moisture sensitive element metal blade 14 generally referred to in the 22 actuating an indicating device 24 or a trade as a doctor, the lower edge of which. recording device or a regulating device as 90 is in intimate contact with the roller cylinmay be desired. For practical reasons I der 10. The doctor, which serves the emerprefer to produce a continuous flow of a gency purpose of loosening and lifting the sampling stream by means of a suction blowweb of paper free from the cylinder is also er 23 l a'st andard part of an equipment of this i The operation and its significance are as .95

40 type. i follows:

' The invention consists in an arrangement The paper manufactured is passed over the whereby the parts referred toare utilized to drying cylinders. The surface portion of form a collector box for directing a gas or the web forming part-of the collectorspace .air into contact with a surface portion of the described has a definitely limited area. The 100 web of paper, at the exclusion of the atmosamount of moisture given off in a unit of time "phere mormally surrounding the paper. by this changing surface of constantarea is Having special reference to Figs. 2 and 3," therefore a measure of the moisture content the space between the doctor, the lower dryof the web of paper at the particular point ing cylinder 10, the web of paper 11 on the of travel, assuming that the other conditions 105 upper left-hand drying cylinder 10, the felt of operation are fairly constant. roll 12 and the felt 13 is converted into a By preparing air of constant temperature collector box for the passage of air in conand constant relative humidity,i. e. of contact with the portion of the paper'web passstant properties as to temperature and hu-.

ing continuously past the space. As seen midity for passage through the collector 110 from Fig. 2, between theupper edge of the space, the moisture content of the air pass doctor blade 14 and the felt roll there is ing o'ut of'the latter is a reliable criterion tions in the moisture content can be indicated, recorded or otherwise utilized for the control of the drying operation.

Provisions may be made to shield the collector space against the effects of heat from the lower cylinder 10'or other parts other than the web, but I have found thatthese effects do not introduce any appreciable errors, but on the other hand, have beneficial action in that they cause a rise of the temperature of the air passing through the collector space and thereby reduce or even prevent condensation or sweating.

In some instances I find it desirable or even practically necessary to at least part-- ly close up the end of the space where the suction nozzle 18 is located in order to obtain the proper amount of positive pressure in the collector space.

In the foregoing I have made reference only to air as a medium for the absorption of moisture, and more in particular to conditioned air. It is understood the invention is not affected by the character of the gaseous medium.

For the sake of brevity in the claims, the word doctor designates a blade so positioned in contact with a roll adjacent to the line at. which aweb of paper passing over the roll normally draws away from the latter, as to immediately lift the paper from the roll in case the paper should stick to the roll beyond the normal line of separation.

I claim:

1. In apparatus of the character described, having two rows of drying rolls in staggered relation, wherein a web of paper passes alternately over a roll of each row, a felt roll between adjoining rolls of one row and opposite a roll of the other row and a doctor disposed between the felt roll and the last mentioned roll and bearing on the latter, the combination with the doctor, of a sheet of flexible material attached to the doctor and bearing upon the felt roll, whereby the doctor and the sheet form a partition connectmg the felt roll and the drying roll upon which the doctor bears.

2. In apparatus of the character described,

having two rows of drying rolls in staggered relation, the combination with two adjoining rolls of one row, a felt roll disposed between the adjoining rolls carrying a belt for movement over the adjoining rolls, the drying roll of the other row, disposed intern'iediate the "said adjoining rolls and a. doctor disposed between the felt roll and the said roll of the other row and bearing upon the latter, of a sheet of flexible material attached to the doctor and bearing upon the felt roll, whereby the doctor and the sheet form a partition substantially coextensive with the rolls.

3. In apparatus of the character described, having two rows of drying rolls in staggered relation, wherein a web of paper passes alternately over a roll of each row, a felt roll between adjoining rolls of one row carrying a felt passing over said adjoining rolls, a doctor disposed between the felt roll and the adjacent roll of the other row bearing upon the latter, the combination with the doctor, of a sheet of flexible-material attached to the doctor and bearing upon the felt roll, whereby the doctor and the sheet form a partition connecting the felt roll and the drying roll upon which the latter bears, and defining with the last mentioned drying roll, the felt on the felt roll and the web of paper a conduitfor a gas, means for passing a gas into one end of said' conduit and means for withdrawing gas from the other end of said conduit.

4. In apparatus of the character described, having two rows of drying rolls in staggered relation, wherein a web of paper passing alternately over rolls of the two rows, in con-- junction with the rolls defines trough-like spaces intermediate the ends of the latter, a felt roller disposed between two rolls of one row, carrying a felt passing over the-two rolls and a doctor disposed between the felt roll and the opposite drying roll of the other row and bearing upon the latter, the combination with the doctor, of a sheet of flexible material attached to the latter and disposed to bear upon the felt roll, the doctor and the sheet forming apartition for separating the trough-like space into two sections and means for passing a gas through one of the said sections to absorb moisture from the web of paper which forms a part of the conduit.

In testimony whereof I afiix my signature.

GEORGE S. WVITHAM, J n.

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