US1557921A

US1557921A - Process of and apparatus for drying materials

Info

Publication number: US1557921A
Application number: US462439A
Authority: US
Inventors: Buel Hillhouse
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-04-18
Filing date: 1921-04-18
Publication date: 1925-10-20
Anticipated expiration: 1942-10-20

Description

uc ZU, H. BUEL PROCESS OF AND APPARATUS FOR DRYING MATERIALS Filed April 18, 1921 5441mm tor V HILLHUUSE EL/EL Y Patented Oct. 20, 192 5.

. HILLHOUSE BUEL, OF SEATTLE, WASHINGTON.

raoonss or AND nrrnniirusron. DRYING mnrrmmns. Y

Application flle'd April 18, 1921. Serial 110,462,439.

I To all whom it'may concern; i

Be it known that I, HILLHOUSE BUEL, a citizen of the United States, residing'in the borough of Manhattan, city, county, and State of New York, har e invented certain. new and useful, Improvements in Processes of and Apparatus for Drying-Materials, of which the following is a full, clear, and complete description.

My invention relates the art ofv extract-.

ing moisture from materials and has as its principal object the provision of a process whereby moisture may be removed frogn materials economically and at a high rate of speed. A second object of my invention is to provide a process whereby materials may be comminuted in a rapid and economical manner with a minimum damage to the granular or the fibrous structure. A further object of my invention is to provide a process whereby materials may be dried at a maximum rate of speed without injury to the material. A further object of my invention is to provide a drying apparatus adapted for use in accordance wlth my process, and which will be convenient and efficient in operation. v

The novel features of' my invention are pointed out. with. particularity in the appended claims. The invention itself, however, with further objects and advantages,

will best be'understood from the following description taken in connection with the accompanying drawing in which Fig. 1 is a vertical central section of a moisture extractor according to my invention.

Fig. 2 is an elevation of a liquid separator preferably used in connection with the apparatus shown in Fig. 1.

-Fig. 3 is a diagrammatic elevational view of the condenser used in connection with the I apparatus illustrated in Fig. 1.

Fig. 4 is a detail view illustrating the heating elements of the extractor shown in F ig. 1.;

In the drawing, 1 is a vacuum chamber having an outer heat insulating covering 2 and a lining 3 adapted to serve not only as an additional means for preventing the es-' cape of heat from the interior of the chamber 1, but more particularly for preventing harmful reaction between the metal wall of -most point in their rotation. livered to the conduit 6 from a hopper 8' chamber 13 and is surrounded the chamber and the material being treated,

as well as to protect the metal wall from the temperature within chamber 1.

Material is supplied direct] pockets 5 therein, in which the material lodges as the pockets pass through the lower portion of conduit'6. The drum 4 rotates within a block 7 and the surface of the drum,

with the exception of the pockets 5, makes a working fit with. said block whereby excluded,-but material which'lodges 1n pockets-7 is conveyed out of the I dropped into'the central upper portion of p to the chama ber by a rotating-feeding rum 4" having air is conduit 6- and chamber 1 as the pockets pass by the lower- Material is deinto which-it is fedby'feed pipe 9. pre

fer. to providean agitator 10 in the hopper 8 and a conveyoror feed worm 11 in the conconveniently mounted-on a common shaft 12. The major portion of conduit 6 is preferably enclosed within --a heat insulated ing coil 14 or other means for maintaining the temperature. within the conduit 6110- initially heat the material.

In case the materials solids mixed with excess of liquid, I remove the excess of liquid-by passing the materials over a screen or by means for eifecting such separation being i1- lu'strated in Fig. 2, in ,which 15 indicates a chamber'contalning an inclined screen 16. Material mixed with water is introduced into the chamber 15 through pipe 17, the

to be dried comprise other suitable means, a

duit 6, agitator 10 and worm 11 both being -7 by the heatsolid matter passing down stream 16 under" the influence of pipe 9 by whic itis conducted to the feed hopper 8 of the apparatus previously described. The liquid passing through screen 16 is drained out of chamber15 through pipe 18, and runs to waste.

Within the chamber 1 I arrangeheated

elements

19 and 20.

Elements

19 and 20 are preferably arranged near thewall of the chamber 1, and are covered on their outer sides by heat insulation 21, their inner sides radiating heat toward ,the centre of'the chamber. Preferably,,moreover, the inner surfaces of these elements are so arranged as (Donate a zone of intense radiant heat at gravity and out through the diant energy ;in,-a. circular line whose plane will be understood, however, that the lines is above drum",4, ithe major portion of the rays of energy from opposite sides of the element 19 crossing immediately below drum 4, as indicated by the lines 22 in Fig. 1. It

22 and 24 represent only diagrammatically a portion of the energy rays, and that other rays radiate in various directions from the heat sources in the element 19 and that while the zone ofinost intense heat will be as illustrated at the intersection of the

diagrammatic lines

22 and 24, the entire interioror-bowl' of the radiant elements will be at a high heat. The circle on which element 19 tends to focus is indicated on Fig.

1 by the

points

23, 23. Not all the rays of energy will, however, focus exactly at these points. The element 20 is arranged, as illustrated, to have a cylindrical inner face projecting its rays of radiant heat horizontally in a zone lying immediately below the block 7, as indicated by the lines 24. Where therays 22 cross rays 24 immediately below drum 4- is of course the point of most intense heat.' I may increase focusing, as shown, in order that the mate-- rial dropping from the pockets 5 and drum 4 may be acted on somewhat longer by the the intensity of the radiant-heat or energy immediately below drum'4 by forming the element20 so as to focus atth'is point, but I prefer that element 20 should be nonradiant heat. The elements 1 9 and 20 are supported from the wall of chamber 1 by suitable brackets, such as 25. I prefer to make these heaters or

radiators

19 and 20 of the electric type wherever cheap electric power is available as in regions adjacent ydro-electric developments, but where electric power is expensive, it is more economical to use other methods of heating the radiators and have illustrated insulating bushings 26 extending throughthewall of chamher 1 through which electric conductors" 27 may be connected with the heaters. In the apparatus illustrated in Fig. II have arranged the resistance members ofelements19- and 20 in series so that only two bushings 26 are necessary. However I do not limit myself-to this. The

elements

19 and 20 preferably are made of insulating material of somewhat refractory character, such as-fire clay and the resistance members are arranged in the refractory material in a well known manner, as indicated at 28, Fig. 4, the resistance wires being insulated-from the radiating body by a layer 28 of mica or like material. However, I do not limit'myself to any particular design of radiator.

The upper portion of chamber 1 connects with

vapor conduits

29, 29, which are combined and connected toa pipe 30 (Fig. 3)-

removed. As the radiant energy is intense inthe zone immediately below the inlet drum 4, the moisture in the material bursts into steam, and if the material is not comminuted, the steam causes such comminution, at the same time that drying occurs. For instance, by myprocess and apparatus, I can produce a dried wood pulp with maximum economy by feeding moist partially digested chips to my apparatus. Due to the action are completely separated, but are of maximum length and strength.

The

temperatureof radiating elements

19 and 20 is preferably as high as the resistance material will stand, as the higher the temperature the more rapid the drying action. The practical operating temperature limit when using nicrome wire as resistance materialis about 1800 F. Other resistance elements, olferi'ng a wide range oftemperatures may, however, be employed. Evidently, however, the higher the temperature of the heater or radiator, the morev rapidly a given material can be passed through the apparatus.

time it falls to the bottom ofthe vacuum chamber: The temperature of the material treated is kept down while in the zone of concentrated radiation by the evaporation and expansion of moisture therefrom and it of the steam, as described above, the fibres The material is dried by the is removed from the vacuum chamber assoon as or almost as soon as dry. The point of outlet for the material being only slight ly exposedto the radiant energy, the material can receive no damage while in the act of being removed from the chamber. -Moreover the sensibletemperature of the portions I be substantially a duplicate of the drum 4. r

The material may then be baled or otherwise prepared for shipment by means of a press 34: or other suitable apparatus. Preferably,

the discharge drum 33 delivers the comminuted and dried material directly to the compressing or packing apparatus illustrated in Fig. 1. The chamber and outlet pipes 29 must be of ample size so that water vapor will pass to the condenser without evidently reducing the vacuum in chamber 1. Moreover I do not wish the active surfaces of

radiators

19 and 20 ever to fallbelow a red heat as then the vapor escaping from the material will slow down the transference of radiant energy to the material to such an extent that the material is not -sutlicientlydried in the zone of concentrated energy. In order to cause comminution of most organic solids the surfaces of these radiators must be at a bright red heat. I

It will be seen that I havedevised a process and apparatus whereby'materials may be dried rapidly with high economy of heat, and without damage to materials, even of a delicate character. I also accomplish comminution of the materials treated at the same time they are dried, provided their character makes it possible and desirable'to do so.

It will be understood that where I have used the word comminute or comminuted in the foregoing description and appended claims, I intend to include the idea of shredding. p

I anticipate using my invention in drying pulp, milk, cotton for spinning, cotton and otherfibrousv material, minerals, and other inorganic and organic substances, as well as simultaneously comminuting and drying woodchips and other materials.

While I have disclosed the preferred. man ner of practicing my invention, and illustrated and described the preferred apparatus according to my invention, I do not wish to be limited to details of description or illustration. 1

Having thus described my invention, 1

' claim 1. The method of comminuting moisture bearing materials comprising suddenly converting the. moisture in the materials to steam by'exposing the materials to intenseradiant energy in vacuo.

2. The method of removing moisture from materials in a vacuum chamber comprising exposing the materials to radiant heat while unsupported in said chamber.

3. An apparatus for drying materials comprisipg in combination a chamber means for maintaining a part1al vacuum 1n sald chamber, means for introducing and removing materials from said chamber, and means for creating a zone of radiant heat through which said materials pass within said chamber.

4. An apparatusfo'r removing moisture from materials comprising in combination a chamber, means for maintaining a vacuum in said chamber, means for introducing ma- 'terial into said chamber, means for creatheat within said'chamber arranged to confcentrate the heat energy radiated thereby within a restricted field.

6. An apparatus for removing moisture from materials comprising in combination means for heating the material to be dried, a'chamber, means for introducing said material. into said chamber while in a heated condition, means for maintaining a partial vacuum in said chamber, and means for subjecting said material to radiant hea within said chamber.

. 7. In combination with a vacuum chamber, means for preheating and compressing moisture bearing materials before delivery to chamber, means for continuously injecting-moisture bearing material into the chamber, means to deliver radiant heat onto the material on its injection into the chamber,

and means to discharge the dried and com;-

material with concurrentdehydration thereof, means for continuously injecting moisture bearing material into the chamber, and means to discharge the dried and comminuted material from said chamber in continuous, automatic operation without breaking the vacuum. 1 v

9. The combination with a vacuum chamber or pan, heating means in saidchamber for causing interstitial explosion of the moisture in and the minute separation of the fibres and particles of the moisture 5 bearing material with concurrent dehydrationthereof, a means for maintaining a partial'vacuum in the chamber, means for continuously injecting moisture bearing material into the chamber, means for discharging the dried and comminuted material in continuous automatic operation from the chamber without breaking the vacuum.

10. In combination with a vacuum chamber, heating means in said chamber for causing interstitial explosion of the moisture in and the minute separation of the fibres and particles of the moisture bearing material with concurrent dehydration thereof, means for preheating and compressing moisture bearing materials before delivery to chamber, means for continuously injecting moisture bearing material into the chamber, and means to discharge the dried and comminuted material from said chamber in continuous, automatic operation without breaking the vacuum.

11. The combination with a vacuum chamher or pan, a means for maintaining a par tial vacuum in the chamber, means-for preheating and compressing moisture bearing materials before delivery to chamber, means for continuously injecting moisture bearing material into the chamber, means to deliver radiant heat onto the material on its injection into the chamber until the material is dried and comminuted, means for discharging the dried and comminuted material in continuous automatic operation from the chamber without breaking the vacuum.

12. The combination of a vacuum chamber, means for maintaining a vacuum in the chamber, means for instant and continuous injection of material into the chamber without breaking the vacuum, a white hot source of radiant heat for simultaneously and almost instantly drying and comminuting the material, and means for discharging dried and comminuted materials from the chamber.

13. The combination of a vacuum chamber, means for preheating and compressing moisture bearing materials before delivery to said chamber, means for maintaining avacuum in the chamber, means for instant and continuous injection of said materials into said chamber without breaking the vacuum, a source of radiant heat for simultaneously and almost instantly drying and comminuting thematerial, and means for discharging driedand comminuted materials from the chamber.

14. In an apparatus of the class described, the combination of a vacuum chamber, a radiator in said chamber, means for maintaining said radiator at a temperature of at least a red heat, and means whereby material to be treated may be introduced into and removed from a zone of energy radiated from said radiator and within said chamber.

15. The process of drying and comminuting moisture containing materials consisting in heating said materials under atmospheric pressure and then subjecting them to the simultaneous action of radlant heat and vacuum.

16. The process of drying material consisting in introducing the material into a field or zone of intense radiant energy in not come in' contact with vacuo and removing said materials from said zone as soon as they are substantially dried. 4,

17. The process of simultaneously drying and comminuting moisture containing materials comprising comminuting the' material by the rapid vaporizationof the contained moisture in vacuo under the influence of intense radiant energy, and substantially removing the material'from the influence of said radiant energy as soon as the material is substantially dry.

18. The process of drying material comprising passing them in vacuo through a zone of radiant energy of an intensity to vaporize substantially all the moisture during the passage of the material through said zone.- c

19. The process of drying materials comprising dropping them in vacuo through a zone of radiant energy of such dimensions and intensity that the material is substantially dried during its passage through said .zone.

20. The process of-simultaneously drying and comminuting moisture containing materials comprising dropping them, in vacuo, through a zone of radiant energy and comminuting and substantially drying said substances b the vaporization of moisture 95 while falling through said zone.

21. The process of simultaneously comminuting and drying moisture bearing substances comprising heating the substance,

injecting said substance into a zone of racontained moisture while falling through said zone.

22. The combination of a vacuum chamber, means to introduce moisture containing materials into \said chamber, a luminous radiator in said chamber to whose radiation the material is exposed, and means for removing dried material from said chamber.

23. The -method of removing moisture from materials comprising exposing the material.simultaneously to vacuum and to direct radiant heat from radiating means having at least one portion at a temperature as great as that of thedark blood red and under conditions'such that the material does the surface of said radiating means.

24. A drying apparatus comprising in combination a chamber, means for maintaining a partial vacuum in said chamber,

means for supplying heat within said cham- 5- 1 means to while in the chamber, means to prevent the material from contact with said heat deliv-' er1 ng means, and means to discharge the drle'd and comminuted material from said chamber in continuous automatic operation without breaking the vacuum, said heat del verlng means comprising a surface a port1on of which has at least a dark blood red temperature.

' HILLHOUSE BUEL.