US3192647A

US3192647A - Drying rolls

Info

Publication number: US3192647A
Application number: US196746A
Authority: US
Inventors: Strube Hauri Robert
Original assignee: S R R I SOC DE RECH S ET DE RE
Current assignee: S R R I SOC DE RECH S ET DE RE; Srri Recherches Et De Realisations Industrielles Ste
Priority date: 1962-03-21
Filing date: 1962-05-22
Publication date: 1965-07-06
Anticipated expiration: 1982-07-06
Also published as: FR1318127A

Description

H- R. STRUBE DRYING ROLLS July 6, 1965 Filed May 22, 1962 United States Patent 3,192,647 BRYENG R6155 Henri Rohe t dtrsshe, iaris, France, assigns: to Albert Madeleine, Nerd, France and SRRJ. Societe de Recherches et de Reaiisahons Industrielies, Paris, France, a French joint-stock company Filed May 22, 1962, Ser. No. 1%,746 Qiaims prioria application France, Mar. 21, 1962, 891,776

The present invention relates to drying rolls which are intended to serve in a general manner for the purpose of drying material in the form of a band which is permeable either to a gas, to a mixture of gas or to steam and, more especially, for the purpose of drying the bands of felt employed in the drying sections of paper machines, board machines, textile machines and the like. The invention is more especially directed to rolls which comprise on the one hand a central body or core which is rotatably mounted in two bearings and is integral with a plurality of radial fins which are preferably equidistant and form channels covered at each end of the roll by an annular wall forming closed passages which are parallel to the axis of the roll and which open into the said channels and, on the other hand, at least one distributor which is placed in contact with one of the ends of said roll and is connected to a chamber inside which there prevails an internal pressure which is diiferent from the pressure prevailing in the interior of the channels, in such manner as to produce inside those channels only which follow that peripheral portion of said roll which is in contact with the band to be dried a circulation of fluid which flows through said band and, lastly, means for providing at least relative fluidtightness in the passage provided for the flow of fluid between the rotary roll and the stationarily fixed distributor.

It can frequently be observed in paper machines that the dryness of the sheet is not uniform over the whole width thereof and in particular that the degree of dryness of the marginal areas diifers from that of the central area.

This irregularity can especially arise from the following causes:

(1) A badly air-conditioned machine room;

(2) An inadequately ventilated machine in which the circulation of air does not take place in a normal fashion in the center of the drying section;

(3) A machine in which the width of the drying rolls is employed to the maximum extent and in which the thermal exchanges are difi'erent at the center and in the marginal areas;

(4) A sheet which reaches the drying section with a degree of dryness which is variable in the direction of the width as a result either of faulty operation of the pulpsupplying unit, or of variation of pressure, or due to any other cause.

These ditferences in drying treatment frequently make it necessary either to reduce the speed of the machine in order to reduce the extent of such differences, or to reduce the effective width of the paper manufactured.

The improvement which forms the subject of the present invention tends to eliminate the aforementioned disadvantages in the drying rolls of the type contemplated and consists in arranging at the periphery of the channels at least one obturating partition which is adapted to slide axially and which is intended to cause the width of the blowing zone to vary and, in the interior of the said channels, stationary directing partitions which are employed in conjunction with an auxiliary distributor for the purpose of producing blowing jets which are distributed according to the requirements of each particular case.

One form of execution of the invention will now be described below, reference being made to the accompanying EJ9164 1 fi a'terrted July 6, 1965 drawings which are given solely by way of example without implied limitation, and in which:

FIG. 1 is a view in elevation of a drying roll, the felt being shown in cross-section;

FIG. 2 is a view in half-elevation and in partial axial half-section on a larger scale, of a drying roll comprising at each end one set of obturating partitions and two sets of directing partitions;

FIGS. 3, 4 and 5 are views in transverse cross-section taken respectively along the line II1III, IV-IV and V V of FIG. 2; and

FIG. 6 is a view in partial axial cross-section showing a telescopic directing partition.

FIG. 1 is a diagrammatic drawing on a small scale which recalls the structural make-up of a drying roll R of the type referred to above, that is to say which is provided with radial fins a (as shown in FIG. 5), the said radial fins forming channels g which are closed-ofi at each end by means of sleeves A A in such manner as to form passages for the supply of drying fluid which are parallel to the axis of the roll. The said rolls are rotatably mounted with interposition of a labyrinth joint I (as shown in FIG. 2) in distributor bearings P P so designed that the blowing aperture I (FIG. 3) of the distributor D is in most cases provided with an angular opening of which corresponds to the arc of winding of the felt band on the drying roll.

In accordance with a preferred form of embodiment of the invention, obturating partitions 0 (as shown in FIGS. 2 and 5) in the form of segments of a cylinder which are iittcd inside the sleeve A are mounted to slide parallel to the axis of the roll inside grooves provided in the fins a which form the channels; the said partitions 0 are designed to permit the width L of the blowing zone to be varied in dependence on the width of the felt band to be dried. This arrangement makes it possible to employ a single set of rolls for one installation, irrespective of the width of the felt and of the sheet of paper to be dried.

In accordance with another form of embodiment which has not been illustrated in the drawings, each obturating partition is formed by a sleeve which is adapted to slide over the periphery of the corresponding annular wall, this latter being preferably arranged in such manner as to ensure that said obturating partition is located in the line of extension of the periphery of the roll.

Directing partitions B B in the shape of a segment of a cylinder are fitted at each end into the fins of each chan nel and comprise end portions b 12 which are bent back transversely with respect to the axis of the roll. The directing partitions B form inside each channel, in combination with the obturating partitions 0 a small passage c in the shape of an annular sector and, in combination with the directing partition B a small passage 0 also in the shape of an annular sector, whilst the partitions B form with the walls of each channel a passage 0 of substantially triangular section. Accordingly, at the outlet of the distributor, the drying fluid is thus subdivided in each channel into three streams 0, c c which are arranged in concentric tiers from the centre of the periphery; the stream 0 follows the central portion of the roll which is limited by the end of each marginal directing partition B whilst the stream c is limited by the two terminal edges [2 b and the stream 0 is limited by the edge b and the extremity of the obturating partition 0 It will be understood that by obturating or closingoi certain passages 0, c and c it is possible to compensate any irregularities in the degree of dryness produced. This is carried into effect by virtue of the invention, by interposing between the main distributor plate D which forms the opening of the blowing arc and the drying roll an auxiliary distributor plate D (as shown in FIGS. 2 and 4) having a central opening which is subdivided, in the example which is illustrated in the' drawings, into three circle sectors S S and S each making an angle of 120 and having respectively a radius equal to that of the obturating partition the directing partition B and the directing partition B It will be understood that when the sector S is located opposite the blowing aperture I of the distributor D the drying fluid will be distributed through the passages c, 0 0 when the sector S comes into position opposite the aperture I the passages 0 will accordingly be closed ott and, when the sector S comes into a similar position, the passages c and c will be closed off and the drying fiuid will be distributed solely through the passages c which are located at the bottom of the channels. The keying in position of the auxiliary distributor D with respect to the main distributor D will be efifected by the penetration of lugs t t and t of the said distributor D in housings l l 1 of the distributor D and by the tightening of a screw V (shown in FIG. 6). It will naturally be understood that the said lugs could be formed on the distributor D and the housings in the distributor D If the felt and the roll are brought into contact over an angle greater than 180, it Will not be possible to form the three sectors S S 53;; on a same auxiliary distributor and it will be necessary to make use of a second auxiliary distributor; the same would apply if more than two sets of directing partitions were employed.-

In accordance with an alternative form which is illustrated diagrammatically in FIG. 6, each directing partition B comprises an extension r in which is formed. a longitudinal elongated slot designed to permit the possibility of securing the said extension in a suitable position by .means of a bolt e This arrangement provides an additional possibility of adjustment.

What I claim is:

1. A drying roll assembly "for treating sheet material with gas which is introduced into the roll and is in contact with the sheet material arranged thereover comprising:

(A) an elongated hollow roll having peripheral opening means for the passage of gas,

(13) plural partition means extending from at least one end of said roll and terminating Within said roll for defining a plurality of coaxial annular channels about the longitudinal axis of said roll for the passage of gas parallel to said axis,

(C) terminal means secured to the terminating portion of said partition means, said terminal means extending substantially radially of said axis for directing gases radially through said peripheral opening means and terminating substantially at the outer periphery of said roll,

(D) a plurality of elongated fins disposed in a circular array about said axis extending radially therefrom and passing radially across each of said channels,

(E) means for introducing gas into said roll and in Cal communication with said coaxial annular channels, and

(F) adjustable distributor plate valve means disposed coaxia lly and in close juxtaposed relation with at least one end of said roll, said distributor plate valve means comprising adjustable aperture means each being of different radial dimension to control the flow of gas through selected ones of said channels.

2. A roll assembly as defined in claim 1, wherein said roll includes an axial core defining the length of said roll and wherein said fins are fixedly attached to said core in a circular array and are adapted to fixedly hold a plurality of elongated strips constituting said partition means.

3. A roll assembly as defined in claim 1, wherein said terminal means are axially slidably secured to said partition means to vary the width of said peripheral openings.

4. A roll assembly as defined in claim 1, wherein said distributor means comprises:

(A) a main plate disposed coaxially and in close juxtaposed relation with said roll at least at one end thereof, said plate having an aperture for limiting the flow of fluid in said channels to a path having a cross-section substantially of an annular sector, and

(B) an auxiliary plate disposed coaxially and in close juxtaposed relation with said main plate and having an aperture composed of a plurality of concentric sectors each having an angle substantially equal to the angle of said annular sector and each having a difierent radius, each of said concentric sectors adapted to be selectively aligned with the aperture of said main plate for allowing the fiow of fluid in selected ones of said channels.

5. A .roll assembly as defined in claim 4, wherein said roll is mounted for axial rotation and wherein said plates are held stationary with respect to said roll.

References Cited by the Examiner UNITED STATES PATENTS 10/52 Germany.

2/36 Great Britain.

5/61 Great Britain.

WILLIAM F. ODEA, Acting Primary Examiner.

NORMAN YUDKOFF, Examiner,

Claims

1. A DRYING ROLL ASSEMBLY FOR TREATING SHEET MATERIAL WITH GAS WHICH IS INTRODUCED INTO THE ROLL AND IS IN CONTACT WITH THE SHEET MATERIAL ARRANGED THEREOVER COMPRISING: (A) AN ELONGATED HOLLOW ROLL HAVING PERIPHERAL OPENING MEANS FOR THE PASSAGE OF GAS, (B) PLURAL PARTITION MEANS EXTENDING FROM AT LEAST ONE END OF SAID ROLL AND TERMINATING WITHIN SAID ROLL FOR DEFINING A PLURALITY OF COAXIAL ANNULAR CHANNELS ABOUT THE LONGITUDONAL AXIS OF SAID ROLL FOR THE PASSAGE OF GAS PARALLEL TO SAID AXIS, (C) TERMINAL MEANS SECURED TO THE TERMINATING PORTION OF SAID PARTITION MEANS, SAID TERMINAL MEANS EXTENDING SUBSTANTIALLY RADIALLY OF SAID AXIS FOR DIRECTING GASES RADIALLY THROUGH SAID PERIPHERAL OPENING MEANS AND TERMINATING SUBSTANTIALLY AT THE OUTER PERIPHERY OF SAID ROLL, (D) A PLURALITY OF ELONGATED FINS DISPOSED IN A CIRCULAR ARRAY ABOUT SAID AXIS EXTENDING RADIALLY THEREFROM AND PASSING RADIALLY ACROSS EACH OF SAID CHANNELS, (E) MEANS FOR INTRODUCING GAS INTO SAID ROLL AND IN COMMUNICATION WITH SAID COAXIAL ANNULAR CHANNELS, AND (F) ADJUSTABLE DISTRIBUTOR PLATE VALVE MEANS DISPOSED COAXIALLY AND IN CLOSE JUXTAPOSED RELATION WITH AT LEAST ONE END OF SAID ROLL, SAID DISTRIBUTOR PLATE VALVE MEANS COMPRISING ADJUSTABLE APERTURE MEANS EACH BEING OF DIFFERENT RADIAL DIMENSION TO CONTROL THE FLOW OF GAS THROUGH SELECTED ONES OF SAID CHANNELS.