US2553516A

US2553516A - Drying apparatus

Info

Publication number: US2553516A
Application number: US733404A
Authority: US
Inventors: Charles A French
Original assignee: Industrial Heat Engineering Co
Current assignee: Industrial Heat Engineering Co
Priority date: 1947-03-08
Filing date: 1947-03-08
Publication date: 1951-05-15
Anticipated expiration: 1968-05-15

Description

y 1951 c. A. FRENCH 2,553,516

DRYING APPARATUS Filed March 8, 1947 v s Sheets-Sheet 1 I amp/ 6- 'ajf zzw. Mag/,-

May 15, 1951 c, FRENCH 2,553,516

- 1mm; APPARATUS Filed March 8, 1947 Sheets-Sheet 2 IN V EN TOR. Z WZmk y 1951 I I c. A. FRENCH 2,553,516

DRYING APPARATUS Filed March 8, 1947 3 Sheets-Sheet s INVENTO Industrial Heat Engineering Company, Greenville, 0., a partnership Patented May 15 1251 r 1.:

Application March fl, 1947, Serial No. 733,404

' Claims.

My invention relates to a methodofand ap paratus for drying cloth and the like. 7 In textile establishments, it is frequentlynecessary to dry cloth after a treatment thereof such, for exampleQas a bleaching operation in which the cloth advances in the form of a very longstrip through a. treating bath. So far as I know, no fullysatisfactory method of and apparatus for drying cloth is known. In accordance with" one practice, the cloth isadvanced rela tively slowly over a series of very large. heated drums. 'Of more recent development isthe practicefby means of suitable apparatus, of bringing th'ecloth into contact with heated air. Various types of apparatus for bringing the cloth in contact with theheated air have been suggested and have, for the'most part, been utilized in recent years'in preference to the heated drum type of apparatus.

I- 'have found that there is much to be desired infthe method of and apparatus for drying cloth Wherethe'principIe employed involves the movemerit of heated air in contact with the cloth.

Y'Theprincipal objectof my invention is the provision of an improved drying method and apparatus.

j Another object is greatly to speed up the dry;

ing operation without deleteriously affecting the cloth, and preferably by improving the sameias contrasted with cloth drying by other methods.,

Still another object is to utilize in a .drying operation in avery'efi lcient manner a mixture of nitrogen and carbon dioxide formed by substantially complete combustion of a hydrocarbon and'super heated steam resulting in part from said combustionand in part from evaporation of moisture from the cloth. f

In carrying out my invention, I provide a plurality'of relatively very narrow passageways adjacent? the. path along .whichthef cloth travels,

and deliver throughsuch narrow passageways in contact With'the cloth at a pluralityo'f locations and successively along the cloth a relatively high temperature gaseous mixture including super heated steam, nitrogen and carbon dioxide. From the standpoint of practice of the method and apparatus therefor I have found the best results to be obtained by causing the cloth to pass over a; series of spaced parallel rollers so arranged that sections of the cloth are parallel to each other. Baffles disposed parallel to the axis of the rollers and in spaced relation therebetween are so di-,

mensioned as to provide'avery narrow passage between thecloth andthe edge ofthe bafile. Hot products ofcombustion' are forced under pressure into a compartment which holds said 'cloth sup porting" rollers and bafiles in such a way as to cause it to pass through allofthe passageways formed betweenthe side edges of the bafiles and the cloth, so that the heated, vapor "successively contacts the cloth with very great intimacy 'at a plurality of points along "the path over which the cloth travels between any two identified rollers. It will be understood, or course, that dure ing the drying movement. of the hot vaporous products, the cloth is continuing to advance so that every part of it will several times be scrubbed by the moving hot vapor by series parallel con 'tact with the cloth. The gases may move with or countercurrent to the movement of the cloth,

or, in some embodiments, at times flowing in'the same direction that the cloth moves, and at times in a direction contrary to the movement of the cloth. The gas, in other words, passes parallel to the cloth in a series of exchanges thereby contacting the cloth several times at several locations.

Preferably the hot vapor moves from one side of the compartment to the other and in making several contacts with the cloth in the manner de-v scribed is reduced markedly in temperature showing a highly efficient operation in evaporating moisture from the surfaces and interstices of the cloth. One compartment may be sufiicient to perform a particular drying operation or several compartments may be utilized. I have found that for many drying operations a two-compartment apparatus can be used to advantage with the efiluent from one compartment discharged into the other together with an additional source of heat such as products of complete combustion of a gaseous or liquid hydrocarbon.

Other objects and features of the invention will be apparent from the detailed description which follows, taken with the accompanying drawings showing one embodiment'of the invention which; has been used to advantage in dryingbleached cotton cloth. p

In the drawings:

i Fig. 1 is a bottom perspective view of a drier constructed in accordance with the features of my invention, with part of the exterior wall broken away to show construction of interior 3 portions;

Fig. 2, is a transverse sectional view takenon the line 2-2 of Fig. 1;

is a longitudinal sectional view taken:

on the line 33 of Fig. 1; r

Fig. 4 is an enlarged'fragmentary perspective view showing the interior construction and cloth arrangement of one'ofthe drying compartments (in this instance the right hand compartment, looking at Fig. 1)

Fig. 5 is a fragmentary perspective view of a single roller and showing the ballle arrangement a and the relation of the cloth thereto, the view being takenat a different angle than that of Fig.

4; and

taken on the line 66 of Fig. 4.

The embodiment shown in the'drawi two cloth compartments Ill and H with a compartment l2 between them housing-a pair of blowers l3 and M. The arrangement within the Fig. 6 is a fragmentary plan sectional view;

ngs utilizes V partment, I provide a plurality of rollers l6.

over which the cloth I1 is advanced. The cloth enters the compartment I!) through a, relatively.

narrow slit I8, is festooned over the several rollers l6, advances to a roller l9 and passes horizontally from the compartment II] to the compartment H where it engages a roller 2|. Thence it is festooned over the plurality of rollers I6 in'the come partment I l and is discharged through a narrow slit 22 at the bottom of the compartment I II The drier may be arranged in'various ways, but it will bemoted that theform shown in the drawings m y; tb'advantage, be supported at or near a ceilins so that the cloth may be moved upwardly and downwardly and to and from the drier and a minimum of space occupied.

The compartment [2 is divided into two

parts ors ections

23 and 24 in which are housed the blowers! 3 and I l, respectively. An opening 23 between the section'24 and the compartment ll permits air to be Withdrawn from said compartmen; H by the'blower I l, and the blower [4 has an outlet 21 to the compartment [0. So also the section 23 is in communication with the compartment I0 through opening 28 and the blower I3 has an outlet 29 to the compartment H; A plurality of burners 3l discharge hot products of combustion into the'section 25$ and at least one burner 32 delivers hot products of combustion to the section 23. A combusible air vaporous fuel mixture is delivered to these burners through a manifold 33. The combustible fuel may be gas premixed with air for substantially perfect combustion, or such products of combustion may comprise fuel oil vapors produced in accordance with the method shown in my prior Pa.ent No. 2,122,684 and premixed with complete combustion.

To bring hot products into contact with the cloth in the manner concemplated by my invention, I provide a plurality of baffles 34, the ends of which are secured to brackets 35 carried on the inside wall of the compartments. These baf fies are so dimensioned and positioned that only areljativelysmall slit, between approxima-.el inch and inch, and'preferably about inch in width, is left on opposite sides of the cloth. The baffles extend entirely across the compartnrnt'and, asparticiilarly shown in Figs. 4 to 6, the edge of the clothpreferably extends almost to the edge of the supporting brackets 36. Above and below the rollers in each of the compart-' ments, I provide a plurality of spaced plates '31 withrelatively narrow slots 38 betweenthem. These plates formseparate semi-closed chambers communicating with the portion of the compartments in which the cloth is disposed only through the slots 38 with the result that pressure is sub stantially equalized and there is a substantially uniform movement of-gaseous products through outth'e entire compartment; structurally, the invention may take various forms, depending upon'the particular type of drying operation, the, accessibility necessary and the type of equipment available. It will be noted by reference to Fig. 1 that I provide for easy access to each compart ment or section of the drier by means of suitable doors capable of being closed to produce a sub} stantially air-tight seal. These are of advantage from a service standpoint and to facilitate intro; duction of the cloth. The blowers may be, operd' n any a le ner s y, m n f air for substantially motor 39 with a pulley drive arrangement 4| to drive the shafts of both blowers from the same motor. In operating the arm of my present invention, the cloth is passed through the drier in the manner shown particularly in Fig. 3 by drawing the same therethrough, although, as in the usual practice, some or all of the rollers over which the cloth is -festooned may be positively driven, if desired. The burners deliver hot prodnets of combustion into the blower compartments where the said hot products of combustion enter the intake side of the blowers and are delivered to"the"compartments for the drying operation. The hot products, of combustion comprise principally nitrogen, 'carbond'ioxide and water vapor. For reasons which will be more fully explained, superheated steam from the cloth itself also is include'din the circulated products. The average pressure within t'h'e 'drier is slightly above atmo's pheric so'tha't no air can enter but within the drier itself there are differences in pressure to promote proper flow."

I have'found that in actual practice with a drier constructed substantially exactly in accordance with the embodiment shown, the average temperature of the gases at the bottom of the compartment 10 will be approximately 500 degrees F. with an average temperature at the top of said compartment of approximately 300 degrees F. The vaporous products from the top of' compartmentll) are delivered into the blower section 23 and are additionally heated by the introduction of hot products of combusthan of the burner 32. 'The temperature at the top of the compartment, I have found to average approximately 3'75 degrees F., while the temperature at the bottom of the compartment H is about 20.0 degrees F. Thus, there is about a 200 'degree temperature drop in the compartment in which the cloth first enters and a degree drop in the compartment in which the final drying operation takes place. The passage of the gas is at] all times parallel to the cloth but the bafile arrangement issuch that a very intimate "contact is obtained between the gas and cloth at"suc c essive stages and, moreover, at each such intimate contact the speed of the gas is greatly increased and there is a much greater scrubbing and. drying action.

The 'nianner of circulatin the hot vaporous products which dry the cloth, may vary greatly depending upon the particular. type and location of installation. It. will be noted by reference particularly to Fig. 3 thatl provide a substantially closed system in which the only additional va ol" introduced into the system results from introduction of hot products of combus: tion' throughthe burners 3,! and 32 and the water vapor, evaporated from the cloth itself. The equipment can be so constructed as to permit venting intdthe room atmosphere, but prefer ably, IfPlQY de' an exhaust duct 42, in 'which is placed a-suitably driven relatively small fan 13. The duct [2; connects to aseparate small chamber formed by the partition 44, and preferably leads to a point exterior, of the building. The

fan 43 has only enough-capacity. to withdraw.

excess vapor, leaving the system as a whole with a pressure slightly, above ambient so that no residual air drawn into the system from the room in swhich thefeguiizvnient is placed. The compartment atmosphere isv forfall practical pur- Q'Ses. th r fo e, ch m call inert '11-. 1 will bese'ni therefore; that the blower. M- drawsv gas. t rnip "the. bpttonr of; the chamber H which gas, comprising principally water vapor,

nitrogen and carbonidioxide, is mixed withhot products of combustion from the burners 3| andv delivered by the blower [4 to the bottom of compartment In. Here, by reason of the plates 31, the mixed hot products are moved upwardly between the bailies 34, thus making high velocity contact with the cloth at; a plurality of points in their movement to the .top of the compartment. The blower l3 wihdraws gases from the top of compartment 10, mixes them with hot products of combustion from the burner 32, and

deliversthe hot products to the top of comparti ment 1 l. where they move downwardly in contact with the cloth between the baffles in the samageneral manner as in compartment [0. Erom; here, except for the .relatively small amount of mixed gases evacuated through the duct 42, the cycle is repeated.

- Those skilled in the art will understand that in addition to modifyin the shape of the drying compartments andjthe disposition of rollers and baflles therein, I may also modify the number of compartments. The recirculating feature may be. used, for example, when employing only aisingle .compartment by placing 'a blower in such a position as to withdraw products from the top of the compartment and deliver the same to the bottom thereof mixed with additional hot products, some of the vapors being suitably vented to maintain the desired pressure conditions. I may also provide more than two compartments, feeding one successively into the other and recirculating from the last compartment to the first compartment. The arrangement employed depends substantially entirely upon the-drying capacity needed, the blower capacity, space'requirements and the like. In

those instances in which relatively slight contact with the fabric is desired the number of rollers may be greatly reduced, as, for example, by providing substantially a straight path for the cloth through the compartment with a relatively large number of successively spaced narrow slits at each of which the textile is scrubbed with the drying vapors, or modified rolls such as corrugated rolls may be employed'to decrease contactof the textile with a surface, all in ways known in the art and with which my invention is not primarily concerned. The important factor is the relatively large number of successive stages in which intimate contact between the, textile and gases traveling at high speed is provided. There is obviously an advantage in providing a compact structure with compartments in which the cloth may be festooned in the mannershown and a relativelylargenumber of successive contacts established, as in the embodiment shown in the drawings, but space and other requirements can be disregarded where necessary'to secure other advantages which particular conditions may require.

When employing my invention, I have found that the cloth is 5% to stronger than cloth dried by conventional methods and that the completely dried cloth is flurfier and has a better feel; The thermal efficiency is unusually great. While the invention is shown as applied to the drying ofcotton textile cloth, it may be used for so-called slasher drying and for thedrying of other types of textiles after various kinds'of treatments such, for example, the application of resin finishes, polymerizing processes, the application of water repellents and the like.

What I claim as new and desire to protect.

by Letters Patent of the United States is:

1. A textile drier comprising two drying compartments with two blower compartments dis-Q posed therebetween, vented partitions at transverse positions above and below the drying compartments to form main drying compartments and upper and lower semi-closed compartments, said main compartments being interconnected by a narrow passage between the blower compartments, a plurality of rollers disposed in parallel rows near the top and bottom of the main drying compartments, the cloth adapted to be festooned over said rollers to provide parallel vertical rows of cloth, rollers in the two said compartments to direct the cloth between the two compartments along said narrow passage,

the compartments having narrow slits for admissioniof the cloth to one compartment and with-- drawal from the other compartment, a plurality of baifies extendingacross the compartments and positioned on each side of the cloth to form a plurality of narrow slits at a plurality of locations between the rollers, so that vaporous fluid passing through the compartments will be caused to scrub the cloth at a plurality of positions at each row of cloth, each said compartment being connected at the bottom with one blower compartment and at the top with the other, a blower in each blower'compartment positioned towith draw vaporous fluid from its compartment and one compartment and discharge into the other compartment, the first drying compartment-being unvented except as described and the second drying compartment having a vent to atmosphere 7 controlled to remove therefrom less vaporous fluid than introduced into the drier, so that a pressure slightly above atmospheric is maintained, and means for introducing hot products of combustion into the circulating atmosphere in such manner that the said products and at-' said main compartments being interconnected by a narrow passage between the blower compartments, a plurality of rollers disposed in parallel rows near the top and bottom of the main drying compartments, the cloth adapted to be festooned over said rollers to provide parallel vertical rows of cloth, rollers in the two said compartments to direct the cloth between the two compartments along said narrow passage, the compartments having narrow slits for admission of the cloth to one compartment and withdrawal from the other compartment, a plurality I of baffles extending across the compartments and positioned on each side of the cloth to form a' plurality of narrow slits at a plurality of locations between the rollers, so that vaporous fluid passing through the compartmentswill be caused to scrub the cloth at a plurality of positions at each rowof cloth, each said compartment being connected at the bottom with one blowercompartment and at the top with the other, a blower; in each blower compartment positioned to with-,

draw vaporous'fiuid from its compartment and one compartment and discharge into the other compartment, a plurality of burners discharging their products of combustion into :the blower compartments between the rollers and the said vented partitions, the burners being so arranged that the compartment which the cloth first enters ishotter than the second compartment, the first drying compartment being unvented except as described and the second drying compartment having a vent to atmosphere controlled to remove therefrom less vaporous fluid than introduced into the drier by the said burners, so that a pressure slightly above atmospheric is maintained.

3. A textile drier comprising two drying compartments with two blower compartments disposed therebetween, said drying compartments being interconnected by a narrow passage between the blower compartments, a plurality of rollers disposed in parallel rows near the top and bottom of the drying compartments, the cloth adapted to be iestooned over said rollers to provide parallel vertical rows of cloth, .rollers in the two said compartments to direct the cloth between the two compartments along said narrow passage, the compartments having narrow slits for admission of the cloth to one compartment and withdrawal from the other compartment, a

plurality of baffles extending across the compartments and positioned on each side of the cloth to form a plurality of narrow slits at a plurality of locations between the rollers, so that vaporous fluid passing through the compartments will be caused to scrub the cloth at a plurality of positions at each row of cloth, each said compartment being connected at the bottom with one blower compartment and at the top with the other, a blower in each blower compartment positioned to withdraw vaporous fluid from its compartment and one compartment and discharge into the other compartment, a plurality of burners discharging their products of combustion into the blower compartments, the burners being so arranged that the compartment which the cloth first enters is hotter than the second compartment, the first drying compartment being unvented except as described and the second drying compartment having a vent to atmosphere controlled to remove therefrom less vaporous fluid than introduced into the drier by the said burners, so that a pressure slightly above atmospheric is maintained, and means for distributing the incoming vaporous drying fluid substantially-equally over the drying compartment.

4. A textile drier comprising two drying compartments and two blower compartments, vented partitions at transverse positions above and below the drying compartments to form main drying compartments and upper and lower semi-closed compartments, said main compartments being interconnected by a narrow passage, a plurality of rollers disposed in parallel rows near the top and bottom of the main drying compartments, the cloth adapted to be festooned over said rollers to provide parallel vertical rows of cloth, rollers in the two said compartments to direct the cloth alongsaid narrow passage from one compartment to the other, the compartments having narrow slits for admission of the cloth to one compartment and withdrawal from the other compartment, a plurality of baifies extending across the 8 positions at each row of cloth, each said com"- partment being connected at the bottom with one blower compartment and at the top with the other, a blower in each blower compartment positioned to withdraw vaporous fluid from its compartment and -nne compartment and discharge into the other -compartment, .a plurality of fburners discharging their products of combustion into the blower compartments, the burners being so arranged "that the compartment which the cloth first enters is hotter than the second compartment, the first drying compartmentrbeing unvented except as described and the second drying-compartment having .a vent to :atmosphere controlled to remove therefrom less vaporous fluid than introduced into the drier by the said burners, so :that-a pressure slightly above atmospheric is maintained.

5. A textile drier comprising two drying compartments with two blower compartments disposed 'therebetween, vented partitions at transverse positions above and below the drying compartments to form main drying compartments and upperrand lower semi-closed compartments, said main compartments being interconnected by a narrow passage between the blower compartments, a plurality of rollers disposed in parallel rows near the'top and bottom of the -main'drying compartments, the cloth adapted to be .festooned over said rollers to provide parallel vertical .rows of cloth, rollers 'in the two said compartments to direct the cloth between the two compartments along said narrow passage, the compartmentshaving narrow slits for admission of the cloth to one compartment and withdrawal from the othercompartment, a plurality of bafiies extending across the compartments and positioned on each side of the cloth to form a plurality of narrow slits at a plurality of locations between the rollers, so that vaporous fluid passing through the compartments will be caused to scrub the cloth at a plurality of positions at each row of cloth, each said compartment being connected at the bottom with one blower compartment and at the top with the other, a blower in each blower compartment positioned to withdraw vaporous fluid from its compartment and one compartment and discharge into the other compartment, a plurality of burners discharging their products of combustion into the blower compartments, the burners being so arranged that the compartment which the cloth first enters is hotter than the second compartment, the first drying compartment being unvented except as described and the second drying compartment having a vent to atmosphere controlled to remove therefrom less vaporous fluid than introduced into the drier 'by the said burners, so'that a pressure slightly above atmospheric is maintained.

CHARLES A. FRENCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 444,860 Stetson Jan. 20, 1891 629,318 Gage. July 18, 1899 1,509,673 Kerst et al Sept. 23, 1924 2,065,636 Whipple 'et al Dec. '29, 1936 2,384,990 French Sept. 18, 1945 2,456,301 Miller et al. Dec. 14, 1948