US2033215A - Drier - Google Patents

Description

March 10, 1936. H. B. WHITMORE DRIER Filed Dec. 15, 1932 2 SheetsSheet 1 IN VEN TOR.

March 10, 1936. B. WHIT R; 2,033,215

DRIER Filed Dec. 15, 1952 2 Sheets-Sheet 2 IN VEN TOR.

ffaraaefi Zr/Zara W A BY Patented Mar. 10, 1936 DRIER Horace Bryan Whitmore, San Francisco, Calif. Application December 15, 1932, Serial No. 647,334

9 Claims.

This invention relates to driers and more particularly to a continuous rotary type of drier suitable for vaporizing the liquid constituents from a semi-fluid slurry as, for example, in the industrial chemical field.

One of the principal objects of this invention is to provide a continuous drier which is simple in construction, inexpensive to operate, and which will have a high surface area for adhesion with the semi-fluid substances which are to be partially dried or thickened.

Another important object of the invention is to provide a novel method of drying or thickening semi-fluid sludges or slurries by dipping suitable projections into the slurry and then drying the adhesively contacted material and finally discharging the solid matter.

Another object of the invention is to provide a rotary drum type of drier adapted for intermittent or continuous operation and provided with a series of projecting slurry pick-up elements of relatively long length and small cross section having a large surface area to pick up a surface layer of slurry, the pick-up elements being secured to the drum in a simplified and easily demounted manner.

Another object of the invention is to provide a drier with an improved discharging device cooperating with long flexible projecting elements which will tend to deflect them from their normal path, thus causing a discharge on both the rebound and primary movement.

Another object of the invention is to provide a hood particularly adapted to increase the loca1- ized heat adjacent the elements carrying the mixture to be dried.

A still further object of the invention is to provide a plurality of unit pick-up elements of projecting channel or U-shape, the entire group of units forming multiple surface areas for temporarily carrying adhered slurry while the volatile constituents are removed and until the solid constituents can be discharged.

Further objects and advantages of the invention will appear from the following description thereof taken in connection with the attached drawings which illustrate preferred forms of embodiment of the invention and in which;

Figure 1 is an end view partly broken away of a continuous rotary drier;

Figure 2 is an end elevation also partly broken away, showing another view of the drier in Figure 1;

Figure 3 is a detail side elevation of a modified unit of discharge element held in demount- The drum or other form of conveyor is provided with a plurality of slurry pick-up elements such as the spiny projections l 6, such pick-up elements being secured to the conveyor in any desired manner. A tank it at the bottom of the drier contains the semi-fluid substance which may be a mixture of solids or colloidal matter and liquid, which matter is to be dried or evaporated. The tank l8 may be filled in any desired manner through the pipe l9.

The drier hood 29 is preferably of C-shape and preferably covers more than half of the circumference of the drum, and is preferably crenellated in shape as shown in Figure 2 to receive each of the rows of pickup elements it to localizethe heat in channels 22. If desired, steam or other hot gases may be introduced within the chamber as of the hood as by the intake pipe 26 and discharged at 28 or vice versa.

In operation, the conveyor carrying the pickup elements is moved so that the pick-up elements are dipped into the semi-fluid mass of slurry in the tank and some of the slurry adheres forming a surface layer on the pick-up elements. The pick-up elements are then carried through the localized heat range in the hood 2t, and the vapors, moisture, etc., will be driven ofi to escape through suitable conduits 38. At a subsequent point in the rotation the pick-up elements which may be of flexible wire type, discharge through the action of a tripping or defiectingdischarger element 32 which may be held in adjustable position adjacent the periphery of the pick-up element is and which will tend to defleet the pick-up elements out of their normal path. As the pick-up elements are deflected, the solid matter which is sufficiently dried is disturbed and on the release of the pick-up element by its passage past the edge of the trip 32, the solid material will be violently shaken and will discharge by gravity over the discharge guard 34. As shown in Figure 2, the discharge guard is also preferably crenellated to engage all of the solids which may be discharged from the rows of pick-up elements 16.

The pick-up elements l6 as shown in Figures 1 and 2 are preferably of a spiny or needle shape and they may be secured to the drum either individually or in pre-secured groups. They may be of round, flat or other shape and arepreferably arranged in one or more rows, each of which projects from the surface of the drum a substantial amount. As their principal function is to cause some adherence of the slurry or semi-fluid material carried in the tank and as they are deflected for discharging they are preferably flexible, of substantial length, and of relatively small cross-section and have a substantial surface area.

In Figures 1 and 2, the pick-up elements I6 are shown secured to the drum which may be brought about by securing the elements to an intermediate collar or retainer member which can be of arcuate form and secured to the drum. The drum may also be perforated and the elements l6 inserted therein. One form of construction showing the intermediate retainer member which may be found to be most suitable is shown in Figures 3 and 4 in which the projections I [6 are secured to a backing or retainer member H8 which in turn is bolted to the drum I H] by suitable bolts I20. This is of particular advantage in that the projections may be removed and replaced as a unit if broken. In the particlar instance the pick-up element projections H6 are of the flat, slat type and may be secured to the backing similar to the construction of a comb and by any preferred means such as welding or bolting or other desired means.

To cover the drum a plurality of these backing elements H8 containing the pick-up elements H6 are mounted together with suitable spacers H4 between them and the entire group secured by a transverse bolt I22. It is of course to be understood that one or more rows on the surface of the drum I I0 may be used and in all events a number of rows will probably be used. Although the particular rows shown are in a plane perpendicular to the axis of rotation, the rows may equally as well be parallel to the axis of rotation or spiral as desired. This particular construction is of special advantage inasmuch as the projections may be removed and replaced if undue damage occurs.

Another form of construction is shown in Figures 5 and 6 in which the spiny projections I50 are in fan or brush formation, a group being secured in a ferrule l52 in a retaining ring I54 which may be the drum itself. As shown in Figure 6, these projections are relatively wide although thin and if desired may be somewhat fan shaped so that the entire greater periphery at the edge of the spiny projections I50 will be substantially continuous. All of the spiny projections spread out in fan shape both laterally and transversely and substantially contact with the spiny projections of adjacent groups at their outer edges.

In all of these forms of construction it will be obvious that the projections from the retaining collars or rings permit great increases in the area of contact for adherence with the slurry which contacts with the projections and forms a surface layer of material which is easily dried from the outside or inside as desired. It is to be understood that the projections may be of steel, aluminum, copper, or other desired metals, or non-metallic products such as wood, rubber, etc.,

depending on the nature of the slurry and the amount to be picked up.

Internal heating of the drum ID in any of these constructions may take place by introduction of heated media through the shafts l2 which are preferably hollow. Steam, for example, may be introduced in one end and discharged through the other, or in fact any other heated gas may be used. The internal heating of the drum effects an additional heat exchange with the spiny projections so that the slurry will become dried a suitable amount.

It is also possible to have the center of the drum provided with spiny projections rather than the periphery of the drum so that the material to be dried will contact with the projections having very much greater surface area and thus causing a quicker drying. This construction may be like the typical cement kiln and the heat may be supplied either directly by internal conduits such as the hollow shafts E2 or by suitable heat applied to the outer diameter of the drum itself.

The projections may be of any desired type and in either circular paths around the periphery of the drum or in longitudinal paths transverse to the drum. It is also to be understood that the speed of rotation of the drum which controls the rate of drying is variably controlled by any suitable motor drive, it being understood that such control may be any standard or preferred device.

It is also possible to have a polygonal type of drum as well as cylindrical and the drum construction as shown in Figure 1 is merely illustrative of the general features of the invention rather than limitive thereof. Other modifications may also be made within the spirit and scope of my invention and I therefore desire a broad interpretation thereof and of the claims appended hereinafter.

I claim:

1. A drier of the class described comprising a movable conveyor, pick-up elements secured to said conveyor, a slurry containing tank in the path of said pick-up elements, and a drying hood covering a portion of said pick-up elements, said pick-up elements being of small cross sectional area and relatively long length and means to flex and vibrate said elements whereby the solid constituents of slurry picked up by said elements and dried by said hood may be discharged from said pick-up elements.

2. A drier of the class described comprising a movable conveyor, pick-up elements secured to said conveyor, a slurry containing tank in the path of said pick-up elements, and a drying hood covering a portion of said pick-up elements, said pick-up elements beingof small cross sectional area and relatively long length and means to flex and vibrate said elements whereby slurry picked up by said elements and dried by said hood may be discharged therefrom, said pick-up elements forming a continuous row affording a substantially large area for adhesive contact with the slurry..

3. A drier of the class described comprising a rotatable element having a plurality of projections secured on one end to the rotatable element and materially increasing the surface area thereof, means to dip said projections in slurry and a heated hood cooperating with said projections to drive off the volatile constituents in the slurry contained thereon, said hood being substantially hollow, and means to detect the other end of said projections to discharge dried slurry therefrom.

4. In a vaporizer of the class described in combination with a slurry tank, a conveyor, a plurality of projections thereon, means to dip said projections into the slurry tank and adhesively contact some of the slurry, means to vaporize the volatile constituents thereof, and means to discharge the residuum from said projections, the projections having a small cross sectional area and a relatively long length, said discharge element consisting of a fixed element projecting into the path of the projections and deflecting them therefrom to discharge the residual dried slurry.

5. A drier of the class described comprising a movable conveyor, a plurality of flexible pick-up elements secured to the conveyor, a slurry tank in the path of said pick-up elements, said elements adhesively picking up some of the slurry, and a drying hood adjacent a part of said conveyor, means to heat the hood, said pi k-up elements passing adjacent the heated hood to reduce the liquid content of the slurry, and means to discharge the dried slurry cake prior to the re-entry of the pick-up elements into the slurry tank, said discharging means deflecting the pick-up elements.

6. In a drier of the class described, the combination of a rotatable drum and a plurality of projecting elements, said projectin elements being secured to an intermediate collar, and means to secure said collars to the drum, said collars and projecting elements having the relation of teeth and the back of a comb, and means to deflect said elements to break the film between adjacent teeth, and set up vibratory motion in said elements.

7. The method of continuously thickening a slurry which comprises the steps of continuously passing a series of separate projecting elements of large surface area and small total volume through said slurry to adhesively form a coating of slurry thereon, subsequently drying said slurry, finally flexing said elements separately and freeing said elements while flexed to vibrate said elements and discharge the solid constituents therefrom.

8. A drier of the class described, in combination with a slurry containing tank and a drying hood, a rotatable drum, a plurality of pick-up elements and means to secure said pick-up elements to the outer surface of said drum, said pick-up elements being secured in rows forming intermediate channels therebetween, said drying hood being crenelated and projecting into said channels, and means to vent said hood above its channels, each of said pick-up elements being relatively long and of small cross section and movable through said slurry containing tank, and means to vibrate said projections to discharge slurry therefrom.

9. The method of drying semi-fluid slurries which comprises the steps of dipping a series of flexible elements into the slurry to adhesively pick up some of said slurry, heating the elements to partially evaporate the volatile constituents and subsequently flexing and freeing said elements While flexed to set up vibrations therein, said flexing of the elements initially breaking the film between adjacent elements, the vibration of an element discharging the solid constituents of the slurry therefrom and rebounding against the adjacent element to set up vibrations therein.

HORACE BRYAN WHITMORE.

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