US2285290A - Drier - Google Patents

Description

`In order that the' the manner desired the drier is provided with a pair of longitudinally'extending main airducts which has been released as a result of the drying of the web fromthe middle portions of the pocketsgtowards thei outer vends thereof and thereby effects a more'uniform distribution of moisture throughoutl'the full width of the web. moisture may be controlled inl I4 disposed along either 'side of .the machine.

Eachair duct Il is provided with a plurality of depending air pipes l5 lwhich are so shaped as to extend horizontally into the respective pockets l2 and Il and terminate at approximately the middle of the length of the pockets. The ends of the opposed Pipes I5 .are disposed in slightly overlapped relation as vindicated at I5 in order that the iiow of air from the ends thereof will not be in uopposed lrelation and thereby create Ian undesired turbulent eifect. The overlapping ends I5. of the pipes may be secured together by .weldi ing l1 or by any suitable form of hand'clamps or thelike.` vItis preferable that the axes of pipes I5 be disposedsubstantially parallel tothe plane of the web in order that thev air currents emitted thereirom'will'not directly impinge upon the web and should be'located in those portions of the complementary pockets il and I 3 in which the web is entering into contact withA a lower cylinder 5. Heated air `may be supplied to the v'pipes l5 through the mediurnA of a vheater and blower assembly generally indicated at A.

litwill be readily apparent that when heated airisl directed through"y the pipes I5, theoppositely vdirected currents set up 4thereby inthe `space of'thefpockets with which thel pipes'are associated. willeect a removal of moistureladen Vairfrom the central portions of the `'pockets towards the ends thereof,y and the majorl quantity lof the moisturel laden air so directed outwardly `Willfbecarried completely out of .the pockets. Therefore most of the moisture laden air which had heretofore been entrapped inthe pockets .will be disposedlof and the drying of the webs will be `rendered more .eilicientv v)Through `the use of the outwardly directed currents of air i carrying the moisture ladenair as described, the

'lower cylinder 5. It is, .of course, possible to havethe pipes. disposed in such manner that they will beeffective to distributethe moisture `over both that portion. or the web which is entering into contact with the upper cylinder andlalso that portion of the web which is entering into contactwith the lower cylinder.. A

i' Fig. 5 of the drawingsy discloses a diagram- 'matic elevation' of 'a multi-section drier in which the sections are separated bya size tub. It will be seen that the airpipes `I5 can be disposed throughout lthe full'length 4of even a drier of the multi-section type `to thereby assure a substantially evenlateral distribution of moisture across the full width of the I web throughout the full-length of the drier.: .n c

The drier may be provided with the usual hood I5 which serves the dual purpose of minimizing heat losses due to radiation and to carry oil the moisture laden air that is displaced from the pockets by the air currents from the pipes l5.

It should not be necessary to provide air pipes *l5 adjacent either the first lower or nrst upper cylinder of the drier, since the web merely has itstemperature raised to drying temperature by contact with those nrst two cylinders and does not give off any great amount of water vapor at that location in the machine.

Thus it will be seen that the herein disclosed invention provides novel means for the handling and disposing of moisture ladenair entrapped Vin the pockets of a drier; which eiIects a movement of moisture from the central portions of the pockets to and out of the ends thereof to thereby provide asubstantially uniform moisture gradient across the full width of the web.

It is, of course, to be understood that certain details yof arrangement in proportions of parts may be variously modified without exceeding the scopeofthe appended claims. A

"I claim: l f

l; In acontinuous web drier having a plurality of vcylinders over which the webis carried, laterally extending open-ended pockets defined by the cylinders and web, and means associated with said` pockets andincluding pairs of generally opposed unrestricted horizontally disposedair pipes having' their open, inner endsdisposed in overlapping relation and terminating in the central portions of said pockets for discharging streams of air in a direction parallel-to the web and slightly spaced therefrom to'thereby carry moisture laden air entrapped in the central portions thereof outwardly towards the ends thereof whereby the moisture content adjacent the central portion of the web will be decreased and the moisture content adjacent the edge portionsA of 'the web will be increasedto thereby effect a substantially uniform moisture gradient across the full width of the web, said pipes being' disposed in substantial parallelism with' 'respect to said web. whereby said currents of air will not Y impinge on the web.

2. In a continuous web drier having a plurality of upper and lower cylinders over which the web iszcarried. laterally extending open-ended pockets defined by the cylinders and web, and moisture regulating means associated with each of said pockets and including pairs of generally opposed air pipes having their open` unrestricted inner ends disposed in overlapping relation and terminating in the central portions oi.' said pockets, said pipes being disposed 'substantially parallel to the planes of the web for discharging streams of air in a direction parallel to the-web withoutV direct impingement thereon and each pair being located inthat portion of a pocket where the web is entering intocontactfwith a cylinder whereby moisture laden air entrapped in the central portions of the pockets will be carried outwardly towards the ends thereof and the moisture content adjacent the'central portion of the web will be decreased and the moisture content adjacent the edge portions of the web will be increased to thereby` provide a substantially uniform moisture gradient across the full width of the web. c v

FRANK 4J. LANG.

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