US2678504A

US2678504A - Apparatus for drying cut staple

Info

Publication number: US2678504A
Application number: US231607A
Authority: US
Inventors: Wallace A Knopp
Original assignee: American Viscose Corp
Current assignee: Akzo Nobel UK PLC
Priority date: 1951-06-14
Filing date: 1951-06-14
Publication date: 1954-05-18
Anticipated expiration: 1971-05-18

Description

May 18, 1954 w. A. KNOPP 2,678,504

APPARATUS FOR DRYING'CUT STAPLE Filed June 14, 1951 INVENTOR. )1 WALLACE A. KNOPP N BY - ATTORNIK LL v Patented May 18, 1954 UNITED STATES PATENT OFFICE APPARATUS FOR DRYING CUT STAPLE Wallace A. Knopp, Parkersburg, W. Va., assignor to American Viscose Corporation,.Wilmington,. DeL, a, corporation of Delaware Application June 14, 1951, Serial No. 231,607

7 Claims. 1

This invention relates toan' apparatus for drying out staple. More particularly, the invention is concerned with drying out staple continuously in spread-out fashion and provides a method and means for periodically redistributing the staple in the layer during the course of drying thereof.

It is generally the practice when drying staple fibers to form the same into a mat or blanket of varying thickness depending upon the type of fiber, but usually on the order of one to three inches in thickness, and then to pass such mat or blanket through a dryer comprising a chamber or housing. Various problems and difllculties are encountered in such a system. For example, it is diiiicult to form mats or blankets of staple fibers which are uniform in depth and density and this results in spottyover-drying and spotty under-drying in the blanket. In addition, the outside of the blanket dries faster than the interior thereof which results in nonuniform drying. Also, to insure thorough drying, the blanket of staple must be kept in the dryer a long length of time which naturally limits production. Thus, there is still much to be desired in the use of a conveyor type dryer in drying out staple fibers.

It is an objectof the present invention to overcome the aforementioned difficulties and disadvantages and provide an improved apparatus for drying out staple fibers. Specifically it is an object of the present invention to provide a new apparatus of the conveyor dryer type which \villdry staple fibers more uniformly and at an increased rate of speed. Further, it is another specific object of the present invention to provide a new apparatus for drying a blanket or mat of staple fibers continuously comprising means for redistributing the fibers in the mat or blanket without the use of movable-mechanical parts which are subject to wear. Other objects and advantages, of the. present invention will be apparent from the description thereof hereinafter. J

In general, the objects of thepresent invention are accomplished by forming, the staple fibers into a mat or'blanket in the usual manner, such as on a screen or roller, etc, and then passing the so-formed blanket onto an endless foraminous conveyor belt which passes through a heated chamber or housing. While in the chamber, the blanket is directed up 'an in cline'd plane and then passed back to thebel'tin such a manner as to break up the blanketand' thus redistribute the' staple fibers therein. The

blanket of staple fibers is assisted up the inclined plane by means of air pressure, that is, a series of nozzles arranged transversely of the direction of travel of theblanket and directed substantially parallel to the direction of travel and against the blanket to thus force the same up the incline.

The belt is made of a foraminous material which is pervious to air. Directly under the belt and at a position coincident with the termination of the inclined plane in an upward direction or slightly back of such point with respect to the direction of travel of the blanket, a vacuum line or duct is arranged transversely of the belt and underneath the same. The vacuum helps to break up the clumps of fibers in the blanket as it comes off the inclined plane and tends to turn the blanket back under the edge of the incline thus facilitating the redistribution of the fibers therein.

The chamber or housing through which the blanket passes maybe heated by any suitable means such as steam coils, electric lamps, and the like. If desired,v hot air may be circulated through the chamber or housing to facilitate the drying of the blanket passing therethrough, care being taken however that the force of the air or velocity thereof is such as not to disturb or disrupt the blanket of staple fibers excessively while on the conveyor belt. Any number of inclined planes may be positioned throughout the chamber depending-of course, upon the amount of redistribution that is required of the fibers in the blanket in order to insure uniform and quick drying thereof.

In order tomore clearly understand the present invention, reference should be had to the accompanying drawing which depicts a preferred embodiment of the invention, it being understood, of course, that thisis merely intended in an illustrative sense and the invention is not to be limited thereby, but only insofar as the same may be limited by the appended claims.

In the drawing:

Figure 1 is the diagrammatic sectional side elevation view of a preferred form of apparatus,

Figure 2 is a plan view, partly in section, of the apparatus shown inFigure l, and

Figure 3 is a plan view of an alternative em bodiment of the invention.

For the" purpose of simplicity of description ofthe invention, the same will be described as it is applicable to'the' drylng' of a rayon staple I to the drying of all types of fibers and in addition other materials, such as molding powders, and similar materials in granular form which may be dried in a manner in accordance with the present invention. For example, there may be mentioned wool, cotton, flax, hemp, regenerated cellulose, cellulose ethers, cellulose esters, casein, alginates, resinous fibers, such as nylon, vinyl acetate, vinyl chloride, and other resins which are well-known in the art.

Referring to the figures of the drawing, the apparatus of the present invention comprises a housing or chamber 3 having steam coils 4 arranged in the top portionthereof. An endless conveyor belt 5 passes around the rollers B and l and through the chamber 3. The belt 5 may be driven by any suitable means (not shown). As pointed out hereinabove, the belt 5 is made of any material which is pervious to air and which will support a blanket of staple fibers.

Positioned directly above the belt 5 intermediate the entrance and exit ends of chamber 3 is a flat, rectangular, plate-like member 8 extending transversely of the belt and forming an incline therewith. The lower end of the plate-like member 8 rides snugly on the conveyor 5. Positioned above the member 8 and transversely of the conveyor belt 5 is a plate or bafile-member 9, If desired, the members 8 and 9 may have a gently curved surface, i. e., convex or concave. V

Positioned in the lower part of the chamber 3 is a high-speed blower or fan 10 having a conduit I l attached to the exit port thereof Conduit H extends upwardly alongside of the conveyor belt and is fastened or connected to the transverse conduit !2 which is positioned above the belt 5. Extending outwardly from conduit I2 is a series of small pipes or nozzles 13 which are directed against the inclined plate-like member8 and nearly parallel to the conveyor belt 5.

To the intake port of the blower fan it there is attached a conduit I 4 which is in turn connected to the upwardly extending conduit [5. The conduit le'in turn is attached to the duct an open mouth across the top in very close proximity'therewith, said duct being positioned directly below the top edge of the inclined member 8. While in the embodiment shown the air is pulled through the duct I6, conduits l5'and l4 to the blower fan l0 and then out through conduits H and I2 and then out the nozzles or jets iii, the air may be drawn into the blower from the outside the chamber 3, as shown in Figure 3. vacuum pump liic would have to be attached to the duct 53. Drawing the air from outside the chamber 3 would be satisfactory provided some means were employed for preheating the air in order not to lower the temperature inside the chamber 3 below the minimum required for efileient drying. The embodiment shown in Figures 1 and 2 of the drawing has the advantage of providing a closed type air circulating system across the dryer and it is'not necessary to pro- In such a case, however, a suitable attained.

blast of air and contains the blanket on the member 8. The blanket rides over the edge of the member 8 and is pulled back under the edge of the member due to the force of the vacuum in the duct I6 under the belt 5. As the blanket passes over the edge of incline 8 and tumbles back onto the belt, it is broken into separate pieces or chunks by the stream of air passing the edge of member 8 induced by vacuum duct I6. The pieces or chunks fall back onto the conveyor belt in a disheveled and turned-over pattern thus redistributing the fibers in the blanket. The blanket then proceeds out the chamber 3 through the exit port 19 and may then be wound on rollers or deposited in cartons or other suitable containers as desired.

An important feature of the present invention is the use of vacuum immediately below the top edge of the inclined member 8. It is important that this vacuum line be positioned di- 'rectly below the top edge or slightly back of such edge, in the direction of travel of the blanket in order to insure the breaking up of the staple fiber blanket and the redistribution of the fibers therein. Without the-assistance of the vacuum, that is, merely allowing the blanket to pass up the inclined plane and then drop back onto 7 the conveyor belt of its own weight, it frequently happens that the blanket is merely flexed and it returns to the conveyor belt with the fibers therein in approximately their same relative position that they had prior to passing over the inclined plane. Naturally, in such a case, proper redistribution of the fibers in the blanket is not In many instances, however, flexing action alone may be desirable. For example, in the case of a blanket of long length staple fibers, i. e., 5 to 6 inches or more, it is extremely matty due to such long fiber length. This matty condi tion makes it extremely difiicult to completely break up the blanket and turn it over. Hence, the flexing action alone is valuable in such a case in that it disturbs the matty condition thus exposing new surfaces and creates a more porous it which extends transverse of the belt 5 and has blanket. However, the best results are obtained when using the vacuum in accordance with the present invention, since the fiber blanket is pulled back under the edge of the member 8, because of the stream of air passing the edge of member 8 induced by the vacuum, in such a manner as to break it up thus insuring good redistribution of the fibers.

As previously pointed out, any type of heating means may be employed in the dryer housing or chamber 3. The housing 3 may be of any desired length and size depending, of course, upon the material being dried and the thickness of the layer or blanket which is passed therethrough. Any number of inclined members and associated apparatus may be employed at spaced intervals in the housing, depending, of course, upon the amount of redistribution of the fibers in the blanket or mat required or desired. Any number of nozzles or jets I3 may be employed to assist the blanket up the inclined plane. The number of nozzles will depend upon the weight of the blanket or thickness thereof andalso upon the angle of inclination that the member 3 makes with the belt 5 and in this connection it should be noted that the angle of inclination may be varied as desired or necessary. An angle of inclination of 5 to 20,'-or more, has been found to be satisfactory.

The present invention provides a convenient means of redistribution, breaking up, or turn ing over of a staple fiber blanket as it passes through a dryer thus insuring quick and even or uniform drying of all the fibers within the blanket. In addition, there are no moving parts inside the dryer and once the apparatus is set and properly adjusted, it will operate indefinitely without any further regulation or close observance. The apparatus of the present invention is easily adapted to use with any of the known standard type of conveyor dryers and in addition, the cost of installation and operation is small. Numerous other advantages of the present invention will be apparent to those skilled in the art.

It is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. An apparatus for drying a continuous blanket of staple fibers comprising a drying chamber, foraminous conveying means in the chamber for conveying the staple fiber blanket through the chamber, a member having a smooth surface mounted in the chamber and extending transversely of the direction of travel of the blanket, said member being inclined upwardly in the direction of travel of the blanket and positioned in close proximity to the conveying means, means for directing the blanket up and over the member, and vacuum means positioned adjacent to and beneath the conveying means and having its open mouth in alignment with the elevated edge of the member for redistributing the fibers in the blanket as it returns to the conveying means. i

2. An apparatus as defined in claim 1 in which the open mouth of the vacuum means is underneath the elevated edge of the inclined member.

3. An apparatus as defined in claim 1 wherein the conveying means comprises an endless conveyor belt pervious to air.

4. An apparatus asdefined in claim 1 wherein the means for directing the blanket up and over the member is pneumatic means.

5. An appartus for drying a continuous blanket of staple fibers comprising a drying chamber, heating means in the chamber, endless belt conveyor means pervious to air for conveying a staple fiber blanket through the chamber, a plate in the chamber extending transversely of the direction of travel of the blanket, said plate being inclined upwardly in the direction of travel of the blanket and having its fiber receiving end contiguous to the conveyor belt, pneumatic means for directing the blanket up and over the plate, and vacuum means positioned adjacent to and beneath the conveyor belt for redistributing the fibers in the blanket as it returns to "the conveyor means, said vacuum means comprising a duct extending transversely of the direction of travel of the blanket and positioned beneath the conveyor means with its open mouth in alignment with the elevated edge of the plate.

6. An apparatus as defined in claim 5 wherein the pneumatic means comprises a conduit arranged transversely of the direction of travel of the blanket and positioned above the conveyor means, a series of nozzles attached to and extending outwardly from the conduit and directed toward the plate, and means for supplying air to the conduit.

7. An apparatus as defined in claim 6 wherein there is a second fiat plate positioned above the first plate to confine the blanket on the first plate.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 473,263 Proctor Apr. 19, 1892 847,038 Ayres Mar. 12, 1907 1,169,682 Sargent Jan. 25, 1916 1,778,318 Haas Oct. 14, 1930 2,360,257 Muller et a1. Oct. 10, 1944 FOREIGN PATENTS Number Country Date 50,883 Austria Nov. 29, 1911 238,094 Switzerland June 30, 1945