US2403800A - Method of and apparatus for drying moisture laden articles - Google Patents

Method of and apparatus for drying moisture laden articles Download PDF

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Publication number
US2403800A
US2403800A US425170A US42517041A US2403800A US 2403800 A US2403800 A US 2403800A US 425170 A US425170 A US 425170A US 42517041 A US42517041 A US 42517041A US 2403800 A US2403800 A US 2403800A
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Prior art keywords
drying
stations
articles
station
cakes
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US425170A
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English (en)
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Cyril N Hoyler
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RCA Corp
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RCA Corp
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Priority to BE474928D priority Critical patent/BE474928A/xx
Priority to FR954488D priority patent/FR954488A/fr
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/46—Dielectric heating
    • H05B6/48—Circuits
    • H05B6/50—Circuits for monitoring or control
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
    • D01D10/04—Supporting filaments or the like during their treatment
    • D01D10/0418—Supporting filaments or the like during their treatment as cakes or similar coreless thread packages
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
    • D01D10/06—Washing or drying
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B5/00—Drying solid materials or objects by processes not involving the application of heat
    • F26B5/04—Drying solid materials or objects by processes not involving the application of heat by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum
    • F26B5/048—Drying solid materials or objects by processes not involving the application of heat by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum in combination with heat developed by electro-magnetic means, e.g. microwave energy

Definitions

  • Cyril N'HOyZer Patented July 9, 1946 METHOD OF AND APPARATUS FOR DRYING MOISTURE LADEN ARTICLES Cyril N. Hoyler, Audubon, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application December 31, 1941, Serial No. 425,170
  • This invention relates to a method of and apparatus for expelling moisture irom moisture-laden articles and has special reference to the drying of water-laden rayon cakes, the present invention being an improvement upon that disclosed and claimed in thecopending application of Rudolph A, Bierwirth, Serial No. 407,619, filed August 20, 1941, now Patent No. 2,325,652, and assigned to Radio Corporation of America.
  • Still another difliculty which is encountered resides in the fact that not only do the outside layers of the cakes dry first with some attendant shrinking and consequent tensioning of the threads at the outer layers, but the inner layers of the thread frequently buckle up and wrinkle as a result of the pressure exerted by the tense, outer thread layers, and an increased possibility of tangling of the thread results. Furthermore, in each strand of thread, a skin shrinkage occurs by reason of the outer surface thereof drying before the inner portion thereof dries with resultant nonuniform appearance in the strand.
  • the primary object of my present invention is to provide an improved method of and apparatus for drying moisture-laden articles, such as rayon cakes, employing the teachings of Bierwirth but utilizing the output of the radio frequency generator much more efficiently,
  • Another object of my present invention is to provide an improved method of and apparatus for drying moisture-laden articles as above set forth in which the drying may be effected rapidly and in great quantities.
  • I provide an arrangement which includes a plurality of operating stations at least one of which is a loading and unloading station, a second of which is an evacuating station, and ne or more other ones of which are drying stations. These stations are arranged in endless fashion and the cakes loaded at the loading station are carried around through the various stations and eventually returned to the first station for unloading the dried cake and loading a new. moisture-laden cake. Suitable means are provided for evacuating. at the evacuating stations, the chambers in which the cakes have been de posited and for thereafter maintaining the vacuum at the successive drying stations.
  • each cake becomes drier, its impedance increases and it becomes more difficult to get power into the cake.
  • Figure 2 is a central sectional view of one of the drying chambers formed according to my present invention
  • Figure 3 is a curve showin the oscillator input for drying a single rayon cake
  • Figure 4 is a set of curves showing the oscillator input requirements per cake for a number of such cakes, and the total input to the oscillator when a fresh cake is added at suitably spaced intervals,
  • Figure 5 is a central sectional view of a modifled form of drying chamber.
  • Figure 6 is a fragmentary, sectional view of one form of apparatus which may be employed for maintaining a vacuum in the drying chambers and for supplying coolin fluid to the condenser coils therein, and
  • Figure 7 is a somewhat enlarged, sectional view taken on the plane of the line VII-VII of Figure 6.
  • FIG. 1 I have shown a suitable enclosure I of dielectric material supported on a base or platform 3 and providin a chamber within which are a pair of spaced, primary electrodes 5 and 1 connected to the tuned circuit 9 of a suitable oscillator through a variable capacitor i i in series with the tuned circuit 9.
  • the interior of the enclosure i may be evacuated by a. su table 4 vacuum pump (not shown) coupled to the charm her through a conduit i3.
  • a cooling coil i5 "within the enclosure I may be connected to a suitable source of cooling fluid for condensing the moisture which is expelled from the cakes, the condensed moisture being "withdrawn in any suitable manner, as through the vacuum line ii.
  • the primary electrodes 5 and I are preferably constituted by circular plates, the lower electrode 1 being supported on an insulator il.
  • One or more rayon cakes i8 may be placed between the electrodes 5 and l and a high frequency electric field applied thereto by the oscillator.
  • a pair of secondary electrodes, such as the guard rings II and 23, are preferably arranged around the primary electrodes 5 and 1 external to the container i and are connected in shunt relation with the primary electrodes, the secondary electrodes serving to help make the field through the cake or cakes i9, as the case may be, more uniform by confining the end effects between the primary electrodes ii and I to a region well outside of the cake IS, with a consequent improvement in the uniformity of drying.
  • a rotatable platform or turntable 25 adapted to be rotated by any suitable means, such as a motor 21, in a manner such that any point on the turntable will successively pass a plurality of stations I to VI, inclusive, arranged in an endless path.
  • stations I to VI At each of the stations may be located an enclosure i and associated parts, as described above in connection with Figure 2.
  • station I represents the loading and unloading station from which a fresh, moistureladen cake is started on its path in the drying cycle, and to which it is subsequently returned when dry
  • stations II and III constitute evacuating stations at which the respective enclosures or chambers l are evacuated
  • stations IV, V and VI constitute successive drying stations at which the drying operations take place, in turn.
  • each 01' the enclosures I may have united therewith one plate or electrode A1 to Avr, inclusive, of the capacitor H, the plates Ar-Avr moving in unison with their respectively associated enclosures I.
  • the capacitor II may, in each case, be completed by a cooperating elec- -trode Brv, Bv, Bvr in each or the load circuits- 28a, 29b and 290, respectively,'the electrodes BIV,
  • each chamber I after being suitably evacuated at stations II and III, will first reach station IV at which its electrode A will cooperate with the electrode Brv o1 capacitor I Ia to apply a predetermined voltage to the cake or cakes contained therein. Subsequently, when the particular chamber under consideration is moved to station V, its electrode A will cooperate with the capacitor plate Bv and a higher voltage will be applied to the cake or cakes therein. Finally, when the same chamber is moved to station VI,
  • a system such as shown in Figures 6 and 7 may be employed. This may consist of three concentric, stationary pipes l0. I2 and ll of which the pipes Ill and I2 are closed at their upper ends by fluid-tight closures I6 and I8, respectively, and the pipe I4 is open at its upper end.
  • the pipe III is connected to any suitable vacuum pump and is formed, near its upper end, with a plurality of ports IOa, I01), I Do and Ifld.
  • the port Illa is preferably elongated and may extend from a point X between the stations I and II to a point Y shortly in advance of the station IV.
  • the port Iflb may be relatively short and is located between the stations IV and V.
  • the ports IDc and Illd are short and are located, respectively, between the stations V and VI and between the stations VI and I.
  • the pipe I0 is formed with an opening We in which a tube or pipe 20 is secured with a fluid-tight connection. the pipe 20 being brought out to the atmosphere in any suitable manner.
  • a sleeve valve 22 Surrounding the ports IUa to I02 and rotatable on th pipe I0 is a sleeve valve 22 having a plurality of internally threaded bosses 24 thereon corresponding in number to the number of stations I to VI and spaced circumferentially from each other on the same angles as are the several stations I to VI.
  • Each conduit I3 is connected to a separate one of the bosses 24 whereby each chamber I may be evacuated in a manner shortly to be set forth.
  • the pipes I2 and I4 extend above the closure I 8, as can be seen from Figure 6, and the pipe I2 is formed near its upper end with a plurality oI. closely spaced ports I 2a extending' circumi'erentially around it.
  • a sleeve valve 26 which is formed with the same number of internally threaded bosses 28 as there are bosses 24 surrounds the ports I2a and is rotatably mounted on the pipe I2.
  • Each of the bosses 28 is connected to the inlet of a separate one of the condenser coils I5 by a coupling tube 20, the outlet of each coil I5 being brought outto the top 01' the pipe I4 by a tube 22.
  • the condenser plate associated with the particular chamber under consideration (for example, the electrode A!) will have come into cooperative relation with the condenser electrode Biv whereby the wet cakes will become coupled to the oscillator and drying will begin.
  • the condenser coil I5 is coupled to the water inlet pipe I2 through the ports I2a. Cool water will flow continuously therethrough and the water vapor driven out of the cakes being dried will be condensed to liquid form and will collect at the bottom of the chamber.
  • the port IUb is eventually reached. This connects the chamber to the vacuum line again for a short period to withdraw the water which has been condensed in the chamber, and this step is repeated at the ports I00 and Illd. Shortly after the chamber being considered has passed the port IUd, its conduit I3 is brought into communication with the opening or port We and the air inlet pipe 20.
  • the curves C of Figure 4 show the loading requirements of each individual cake for a plurality of cakes (assuming only one cake is placed in each of the chambers i at one time). It will be noted that each of the individual curves is similar to the curve shown in Figure 3. It will also be noted that, for drying a single cake, the ratio of maximum to minimum oscillator input is about 3 to 1.
  • the curve D of Figure 4 shows the loading requirements in a system such as that illustrated in Figure l on the basis of a new cake of maximum moisture content added every twenty minutes. From the curve D, it will be noted that the ratio of maximum to minimum oscillator input is approximately 6 to 5.
  • the oscillator may be employed much more emciently than when a single cake is dried at one time, and at the same time the output of dried cakes can be very greatly increased.
  • any number of evacuating and drying stations may be employed, the number shown in Figure 1 being used merely for the purpose of illustration.
  • FIG 5 I have shown a somewhat different form of drying chamber which may be used on the turntable 25 instead of the One shown in Figure 2.
  • the enclosure may be constituted by a metal base 3i and a metal cover 33 fitted together with a cylindrical glass drum or spacer 35.
  • Two or more gaskets I1 may be employed for providing airtight connections between the plates 3
  • the advantages oifered by this form of chamber are (1) that a relatively small volume of air would have to be evacuated, (2) that each cake would be dried under uniform ideal conditions, and (3) that high electrica1 efficiency would be obtained because of the insulation afforded by the glass cylinder 36.
  • a plurality of enclosures constituting a plurality of drying chambers each adapted to receive at least one article to be dried, means for maintaining a vacuum in each of said chambers, means for simultaneously supplying heating energy in at least certain of said chambers for drying the articles therein, a plurality of control elements for controlling the energy supplied to said stations by said second named means, said elements being each adapted to cooperate with a separate one of said chambers during a predetermined drying interval, and means for successively bringing each of said elements into cooperative relation with each of said chambers for successive drying intervals.
  • apparatus for drying moisture-laden articles including a loading station, an evacuating station and a drying station
  • means providing a closed chamber adapted to receive at least one of said articles at said loading station means for successively advancing the loaded chamber to said evacuating and drying stations, means for creating a vacuum in said chamber at said evacuating station and for maintaining the vacuum in said chamber while said chamber is subsequently at said drying station, and means for supplying heating energy to said chamber at said drying station for drying said article.
  • apparatus for drying moisture laden articles including a loading station, at least one evacuating station, and a plurality of drying stations
  • means providing a closed chamber adapted to receive at least one of said articles at said loading station means for successively advancing the loaded chamber first to said evacuating station and then to each of said drying stations in turn, means for creating a vacuum in said chamber at said evacuating station and for maintaining the vacuum in said chamber while said chamber is subsequently at each of said drying stations, means for supplying heating energy to said chamber at each of said drying stations for drying said article, and means located at each of said drying stations for controlling the amount of energy delivered by said last named means at the respective drying stations.
  • apparatus for drying moisture-laden articles including a loading station, at least one evacuating station and a plurality of drying stations all arranged in endless formation, the combination of means providing a closed chamber at each of said stations, means for advancing said chambers in an endless path past said stations whereby each of said chambers is brougt, in succession, first from said loading station to said evacuating station, then from said evacuating station to each of said drying stations in turn. and finally from the last oi.
  • said drying stations back to said loading station, said chambers each being adapted to have a dried article therein exchanged for a moisture-laden article when at said loading station, means for creating a vacuum in each of said chambers while at said evacuating station and for thereafter maintaining the vacuum therein while said chambers are subsequently at each of said drying stations, means for simultaneously supplying heating energy to all the chambers at said drying stations for heating the respective articles therein, and means located at each of said drying stations for controlling the amount of energy delivered by said last named means at the respective drying stations.
  • said apparatus including a loading station, at least one evacuating station and a plurality of drying stations, the combination of means providing a chamber adapted to receive at least one of said articles at said loading station, a pair of cooperative electrodes in said chamber between which said article is adapted to be disposed, means for successively advancing the loaded chamber first to said evacuating station and then to each of said drying stations in turn, means for creating a vacuum in said chamber at said evacuating station and for maintaining the vacuum in said chamber while said chamber is subsequently at each of said drying stations, a source of high frequency electrical energy, and means for coupling said source to said electrodes at each of said drying stations, said means including a plurality of reactance elements in circuit with said source, each of said reactance elements being of different value and each being effective to couple said source to said electrodes at a separate one of said drying stations.
  • each of said capacitors has a different value corresponding to the moisture content of the article being dried when it reaches the respectively associated drying station of each of said capacitors.
  • said apparatus including a, plurality of drying stations, the combination or means providing a plurality of chambers, one at each of said drying stations, and each adapted to contain at least one article to be dried, a pair of cooperative electrodes in each of said chambers between which the respective articles are adapted to be disposed, means for maintaining a vacuum in each of said chambers at each of said drying stations, 9.
  • a plurality of coupling circuits each including a reactance device and each coupling said source to a separate pair of said electrodes, said reactance devices each including a pair of relatively movable elements one of which is united with its associated chamber and the other of which is connected to said source, and said reactance devices being of different value whereby the energy supplied to said respective articles is dependent upon the particular reactance device coupled thereto, and means for effecting relative movement between said chambers and said source whereby to effect relative movement between said respective elements and thereby alter the value of the reactance device connected to any one of said chambers at any particular time.
  • a high frequency oscillation generator including a tuned circuit of a plurality of parallel-related, movable load circuits selectively coupled in series with said tuned circuit, each of said load circuits including a reactance element and being adapted to receive in series with its reactance element a variable impedance element having a different impedance than the impedance of any other of said load circuits, said impedance elements each consisting of at least one of the articles being dried, and said reactance elements being of different values to couple predetermined high frequency power to each of said impedance elements in accordance with the relative positions of said articles.
  • a high frequency oscillation generator including a tuned circuit of a plurality of parallel-related, movable load circuits selectively coupled in series with said tuned circuit, each of said load circuits being adapted to receive therein atleast one of said articles in a different state of dryness than an article of another of said load circuits and including a serially connected variable reactance element, and means for transferring each of said articles successively from one of said load circuits to another, each of said reactance elements having a different value whereby to couple different predetermined high frequency power to each of said articles in accordance with the relative positions thereof.
  • a high frequency oscillation generator including a tuned circuit of a plurality of parallel-related load circuits connected in series with said tuned circuit, said load circuits each being adapted to receive therein at least one of said articles in a different state of dryness than an article of any other of said load circuits, and means including variable reactance elements for altering the voltages applied by said generator across each of said articles in correspondence with the moisture content therein.
  • a high frequency oscillation generator a plurality of parallel load circuits coupled in series with said generator and each adapted to receive therein at least one of said articles in a different state of dryness than an article of any other of said load circuits, and means for periodically varying the coupling between said generotor and said load circuits in accordance with the moisture contents of said articles at predetermined times whereby to maintain the power load on said generator within certain predetermined limits.
  • 17.111 electrical apparatus for drying moisture-laden articles the combination of a pair of primary electrodes disposed in spaced relation to each other and adapted to receive at least one 2,4os,soo

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Molecular Biology (AREA)
  • General Engineering & Computer Science (AREA)
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US425170A 1941-12-31 1941-12-31 Method of and apparatus for drying moisture laden articles Expired - Lifetime US2403800A (en)

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BE474928D BE474928A (xx) 1941-12-31
FR954488D FR954488A (xx) 1941-12-31
US425170A US2403800A (en) 1941-12-31 1941-12-31 Method of and apparatus for drying moisture laden articles

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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485609A (en) * 1945-04-19 1949-10-25 American Viscose Corp Drying apparatus
US2490938A (en) * 1945-05-05 1949-12-13 American Viscose Corp Method of drying
US2509181A (en) * 1948-06-22 1950-05-23 Electronic Products Corp Method and apparatus for electronically fusing material in a high partial vacuum
US2546004A (en) * 1947-07-11 1951-03-20 Westinghouse Electric Corp Progressive dielectric heating
US2555450A (en) * 1943-11-29 1951-06-05 Lee Foundation For Nutritional High-frequency dehydrating method and apparatus
US2635352A (en) * 1948-06-24 1953-04-21 American Viscose Corp Method of drying wound packages
US2644073A (en) * 1949-04-01 1953-06-30 Westinghouse Electric Corp Dielectric heating with rotatory work-receiving element
US2650290A (en) * 1949-09-20 1953-08-25 Westinghouse Electric Corp Conveyer system for induction heating
US2655711A (en) * 1950-01-05 1953-10-20 E Z Mills Inc Shrinkproofing of fabrics
US2791173A (en) * 1953-08-10 1957-05-07 Drewry Photocolor Corp Apparatus for making photographic color print
DE1125360B (de) * 1956-07-30 1962-03-08 Magnetic Heating Corp Kammer zum Trocknen fester Gueter im kapazitiven Hochfrequenzfeld
DE1246587B (de) * 1965-04-01 1967-08-03 Siemens Ag Vorrichtung zum kapazitiven Erwaermen zu trocknender zylindrischer oder prismatischer Koerper, z. B. Spinnkuchen
US3615310A (en) * 1969-06-02 1971-10-26 Ppg Industries Inc Method for drying glass fiber forming packages
US5199189A (en) * 1992-07-02 1993-04-06 Davidson Textron Inc. Waterbased clearcoat drying apparatus
EP0548746A1 (en) * 1991-12-26 1993-06-30 Nikku Industry Co., Ltd. Vacuum drying apparatus

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2555450A (en) * 1943-11-29 1951-06-05 Lee Foundation For Nutritional High-frequency dehydrating method and apparatus
US2485609A (en) * 1945-04-19 1949-10-25 American Viscose Corp Drying apparatus
US2490938A (en) * 1945-05-05 1949-12-13 American Viscose Corp Method of drying
US2546004A (en) * 1947-07-11 1951-03-20 Westinghouse Electric Corp Progressive dielectric heating
US2509181A (en) * 1948-06-22 1950-05-23 Electronic Products Corp Method and apparatus for electronically fusing material in a high partial vacuum
US2635352A (en) * 1948-06-24 1953-04-21 American Viscose Corp Method of drying wound packages
US2644073A (en) * 1949-04-01 1953-06-30 Westinghouse Electric Corp Dielectric heating with rotatory work-receiving element
US2650290A (en) * 1949-09-20 1953-08-25 Westinghouse Electric Corp Conveyer system for induction heating
US2655711A (en) * 1950-01-05 1953-10-20 E Z Mills Inc Shrinkproofing of fabrics
US2791173A (en) * 1953-08-10 1957-05-07 Drewry Photocolor Corp Apparatus for making photographic color print
DE1125360B (de) * 1956-07-30 1962-03-08 Magnetic Heating Corp Kammer zum Trocknen fester Gueter im kapazitiven Hochfrequenzfeld
DE1246587B (de) * 1965-04-01 1967-08-03 Siemens Ag Vorrichtung zum kapazitiven Erwaermen zu trocknender zylindrischer oder prismatischer Koerper, z. B. Spinnkuchen
US3615310A (en) * 1969-06-02 1971-10-26 Ppg Industries Inc Method for drying glass fiber forming packages
EP0548746A1 (en) * 1991-12-26 1993-06-30 Nikku Industry Co., Ltd. Vacuum drying apparatus
US5199189A (en) * 1992-07-02 1993-04-06 Davidson Textron Inc. Waterbased clearcoat drying apparatus

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Publication number Publication date
FR954488A (xx) 1950-01-03
BE474928A (xx) 1900-01-01

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