US2918070A - Apparatus for material treatment - Google Patents

Description

Dec. 22, 1959 R. M. CARRIER, JR 2,918,070

APPARATUS FOR MATERIAL TREATMENT Filed Jan. 2, 1957 INVENTOR. 9055/? T M CARP/ER JP.

BY I A TTORNE Y5 Fnited htates APPARATUS FOR MATERIAL TREATMENT Application January 2, 1957, Serial No. 632,204

7 Claims. (Cl. 134-132) The present invention relates generally as indicated to apparatus for material treatment and more particularly to apparatus including a vibrating spiral conveyor which has a unique arrangement of helical material supporting pins or flights for effecting continuous heat treatment, chemical treatment, cooling, drying, heating, washing, or other treatment of the material during the course of its travel around such pans or flights. This is a continuation-in-part of my application Serial No. 333,940 which was filed January 29, 1953 for Spiral Conveyor for Material Treatment, now abandoned.

In the heat treatment of castings, the cooling, drying, washing, or heating of various conveyable materials, or the chemical or other treatment of such materials, it has been found desirable to continuously perform such treatments rather than doing the same in batches; but, if a conveyor belt or other known type of horizontal or inclined conveyor is employed, it must often be several hundred feet in length in order that proper treatment will be effected during the course of travel of the material therealong. Obviously, such a conveyor occupies a large floor space and the treating zone similarly must be disposed around a substantial portion of the length of the conveyor.

In order to reduce the floor space occupied by the conveyor to a minimum while yet providing a desired length of conveyor, several hundred feet for example, I have formed the conveyor so that the material to be treated is conveyed in a helical path through the treating zone, first in one direction into the treating zone and then in the opposite direction out of the treating zone whereby, in a relatively small floor space, without requiring excessive height a substantial length of the conveyor is disposed in the treating zone to effect the desired treating of the material during its conveyance.

While in the more specific aspects of the present invention the spiral conveyor is immersed in a liquid treating medium such as an oil quench for metal castings, it is to be understood that the treatment to which the material is subjected may include air cooling, heating, or drying in which event the long length of conveyor and material thereon is exposed to the treating medium or may include coolant sprays or heating sprays, or the like directed against the under surfaces of the flights and/or on the material. The treatment, whatever its nature, may be applied to any materials which are capable of being conveyed; and included are metal castings as aforesaid, gravel, chemicals, aggregates, or any bulk material. Of course, where the material is to be subjected to liquid treatment, the material should be of such character as to be capable of being conveyed while in the liquid. For such purposes, powdered materials and other finely divided materials such as fine sand are generally not so well suited for conveying while immersed in liquid because the particles thereof tend to more or less float in the liquid.

The present application discloses further improvements in the apparatus such as disclosed in my copending ap- "ice plication Serial No. 294,882, filed June 21, 1952, now Patent No. 2,760,503 dated Aug. 28, 1956. It is to be understood that here, as in said patent, perforated flights may be provided through which the fines in the material being treated may drop and thereby be separated from the remaining material. This application also discloses further improvements over my Patent. 2,847,767 which issued August 19, 1958 from co-pending application Serial No. 285,020, filed April 29, 1952, which discloses various arrangements for treating materials during conveying thereof and of providing spiral conveyors having relatively long material supporting surfaces and occupying a small floor space.

It is one object of my present invention to provide a spiral conveyor which has a plurality of helical flights by means of which the material to be treated is conveyed in opposite directions and in helical paths to reduce the floor space occupied by the conveyor to a minimum while yet achieving prolonged time of exposure of the material to the treating medium whether that be a liquid contained as in a tank, a gas surrounding the conveyor, coolant sprays directed at the material supporting surfaces of the conveyor, or equivalent means for effecting drying, cooling, heating, or other treatment of the material during conveying thereof.

It is another object of my invention to provide a conveyor of the character referred to in which the material is conveyed around the helical flights thereof in one direction only, while travelling downwardly around one flight and upwardly around another flight to thus expose the material to the treating medium for the desired length of.

time while the material is continuously in motion from the inlet to the discharge of the conveyor.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. 1 is a central vertical cross-section view of one embodiment of this invention, the drive mechanism being shown in elevation; and

Pig. 2 is a fragmentary elevation view of the upper end portion of the conveyor as viewed from the lefthand side of Fig. 1.

Referring now in detail to the drawing, the conveyor comprises for example, a vertically disposed tube 1 having an external helical flight 2 therearound and an internal helical flight 3 therein, said flights 2 and 3 being of opposite hand as shown, whereby, when said tube 1 is vibrated about its vertical center axis along the path designated by the arrow 4, material to be treated which is supplied as by means of the chute to the upper end of the internal flight 3 will be conveyed downwardly therearound. When the material reaches the lower end of said internal flight 3, the same will be discharged therefrom onto the external flight 2 as by means of the connecting flight portion 6 which extends through an opening 7 in said tube 1. The material will continue to move around the external flight 2 in the same rotary direction, but, because of the opposite hand of said external flight 2, the material will now be conveyed upwardly and will ultimately be discharged from the conveyor through the chute 8.

The treating medium in the particular embodiment of the invention herein shown comprises an oil quench contained within a tank 9 in which the lower end portion of the conveyor is immersed to any desired depth, said conveyor having a center shaft at its lower end which is slidable and rotatable in the bearing 11 mounted on the bottom of said tank. Thus, as the heated castings, for example, are introduced onto the upper end of the internal flight 3, the same will be conveyed through the treating medium, first downwardly and then upwardly to thereby subject the material being treated to the desired action and for a substantial length of time. The two flights 2 and 3 herein taken together may be several hundred feet in length While the only floor space occupied by the apparatus is that of the tank 9 which need be only slightly larger than the diameter of the external flight 2. It is to be understood that the tube 1 is perforate so that the treating medium has access to the internal flight 3 and the material conveyed thereby.

As previously mentioned, the treating medium need not be a liquid in which the conveyor is immersed, but, instead, the material being treated may be cooled, dried, heated, or subjected to any other action by exposure of the flights 2 and 3 and/or the material thereon to the particular media in question. In some instances, it may be desirable to simply spray (coolant or heating medium) the under surfaces of the flights whereby the cooling or heating of the flights, as the case may be, results in cooling or heating of the material while the material is being continuously conveyed.

The vibration of the conveyor along the path 4 is obtained by suspending the conveyor and its top platform 14 from a platform 15 by means of obliquely disposed coil springs 16 and pivoted rods 17 extending from said platform 14 to the platform 15 whereby transmission of vertical energy impulses to the conveyor will, through said rods 17 and springs 16, effect a vibration of the conveyor along a generally helical path 4. The longitudinal axes of said springs 16 are preferably disposed generally parallel to such desired path of vibration 4 and the pivotal connections of said rods 17 to the conveyor platform 14 and to the platform 15 are such that the pivots also move along a path generally parallel to such desired path of vibration. The rods 17 are, of course, rubber bushed or otherwise arranged so that the conveyor can partake of the necessary helical vibration.

Vertical energy impulses are transmitted to the center of the conveyor through an eccentric shaft 20 which operates the connecting rod 21, the latter in turn being linked to the conveyor through an intermediate lever 22 which is pivotally connected to the conveyor bracket 23 and pivotaliy connected to one end of a hydraulic shock absorber 24 or the like. Said shock absorber has its other end pivoted to the platform 15 and provides a fixed pivot 25 at the operating frequency of 500 cycles per minute, for example. However, said shock absorber 24 may gradually lengthen or shorten to allow said pivot 25 and the conveyor to gradually shift vertically to different positions in accordance with the weight of the conveyor and the load of the material being conveyed. It is to be noted that, in the various settled positions of the conveyor, the amplitude of the vertical energy impulses will remain substantially constant whereby said shaft 20 may be rotated to impart energy impulses in resonance with the natural frequency of the springs 16.

The opposite ends of the springs 16 are connected, as shown, to the platforms 14 and 15; and, therefore, said springs 16 are under tension by the weight of the conveyor and the weight of the material thereon.

As aforesaid, where liquid treatment is involved, as shown in Fig. l, the product should have a substantially greater specific gravity than the liquid so that said product during conveying through the liquid will be progressively tossed angularly upward relative to the conveyor flights 2 and 3 as the conveyor is vibrated. Where such liquid is involved, the product will, therefore, be thoroughly washed or otherwise treated by the alternate up 4 and down movement of the product through the body of the liquid.

It is noted that the helical flights 2 and 3 will, by reason of their different diameters and opposite helix angles, have different rates of conveying if the pitches thereof are equal. Therefore, where the material being conveyed and treated moves downwardly around the internal flight 3, said internal flight will preferably have a pitch less than that of the external flight 2 so that there is no possibility of piling up of the material at the bottom of the flights. It is noted further that, because the flights 2 and 3 are at difierent radii from the center axis of the conveyor, the

. horizontal component of the vibration will be less for the internal flight 3 than for the external flight 2; and this, in connection with the reduced pitch of flight 3, will serve to increase the relative length of the internal flight 3 so that the material will be subjected to the desired treatment for a relatively long time as it is conveyed first along the internal flight 3, and then around the external flight 2.

Although the present invention has been herein described as being operated and constructed so that the material is introduced to the upper end of the internal flight 3 and finally discharged from the upper end of the ex ternal flight 2, it is to be understood that it is within the spirit of this invention to reverse such travel, if desired that is, to vibrate the conveyor and provide flights of opposite hand so that the material will be conveyed downwardly around the external flight and upwardly around the internal flight. Likewise, material may be supplied to the lower end of either one of the flights and then be transferred at the top or elsewhere to the other flight for conveying downwardly around the latter. It is further contemplated that more than two flights may be provided, if necessary; and, for example in the embodiment illustrated, the material discharged from the external flight 2 may be carried downwardly by a surrounding flight of opposite hand, and then upwardly by still another surrounding flight, etc.

The instant invention thus provides novel apparatus for material treatement in which spiral conveyors supported and vibrated from above extend downwardly into a treating tank and the material to be treated is conveyed downwardly into the treating medium and thence upwardly, the apparatus occupying little floor space though the material travels a long distance while it is being treated.

The invention is susceptible to modification and change within the spirit and scope of the subjoined claims.

I claim:

1. In apparatus for material treatment, in combination, two helical troughs which spiral in opposite directions about a substantially vertical axis, a tank adapted to contain a processing fluid, the lower ends of said helical troughs extending into said tank, means for transferring material from the lower end of one of said helical troughs to the lower end of the other of said helical troughs, a supporting structure located above the upper ends of said helical troughs, springs connecting said supporting structure and said helical troughs for permitting spiral vibratory movement of said troughs, and means supported by said supporting structure for imparting vibratory impulses to said helical troughs.

2. In apparatus for material treatment, in combination, two helical troughs which spiral in opposite direc tions about a substantially vertical axis, said helical troughs being fixedly connected together, a tank adapted to contain a processing fluid, the lower ends of said helical troughs extending into said tank, means for transferring material from the lower end of one of said helical troughs to the lower end of the other of said helical troughs, a supporting structure located above the upper ends of said helical troughs, springs connecting said supporting structure and said helical troughs for permitting spiral vibratory movement of said troughs, and means supported by said supporting structure for imparting vibratory impulses to said helical troughs.

3. In apparatus for material treatment, in combination, two helical conduits which spiral in opposite directions about a substantially vertical axis, a tank adapted to contain a processing fluid, the lower ends of said helical conduits extending into said tank, means for transferring material from the lower end of one of said helical conduits to the lower end of the other of said helical conduits, a supporting structure located above the upper ends of said helical conduits, springs connecting said supporting structure and said helical conduits for permitting spiral vibratory movement of said conduits, and means supported by said supporting structure for imparting vibratory impulses to said helical conduits.

4. In apparatus for material treatment, in combination, two helical conduits which spiral in opposite directions about a substantially vertical axis, a tank adapted to contain a processing fluid, the lower ends of said helical conduits extending into said tank, means for transferring material from the lower end of one of said helical conduits to the lower end of the other of said helical conduits, a guiding and supporting structure coupled to said helical conduits adjacent their upper ends and above the level of the fluid in the tank to confine said conduits to movement along a spiral path having a substantially vertical axis, and means mechanically coupled to said helical conduits adjacent their upper ends and above said fluid level for imparting vibratory impulses thereto to induce movement along said spiral path.

5. In apparatus for material treatment, in combination, two helical conduits which spiral in opposite directions about a substantially vertical axis, said helical conduits being fixedly connected together, a tank adapted to con tain a processing fluid, the lower ends of said helical conduits extending into said tank, means for transferring material from the lower end of one of said helical conduits to the lower end of the other of said helical conduits, a supporting structure located above the upper ends of said helical conduits, springs connecting said supporting structure and said helical conduits for permitting spiral vibratory movement of said conduits, and means supported by said supporting structure for imparting vibratory impulses to said helical conduits.

6. A helical conveyor device comprising an upright tubular body, inner and outer helical flights of opposite hand respectively secured within and without said body and having their lower ends joined together through an opening in the wall of said body, for conveying of material from one flight to the other, a support, a spring and guide means connected between said support and one end of said body to support the latter, and the flights secured thereto, for vibration along an inclined arcuate path to convey the material loaded on the upper end of said inner flight downwardly therearound and thence upwardly around said outer flight from the lower end thereof for discharge from the upper end thereof, and driving means mounted on said support and connected to said body to vibrate the latter approximately the resonant frequency of said spring means, said inner flight having a pitch less than that of said outer flight to eliminate accumulation of material at the lower ends of said flights, and the connection between said driving means and said body including an element which transmits substantially uniform amplitude resonant vibration to said body and which is extensible to permit settling of said conveyor device on said spring and guide means with respect to said support due to change in load of material on said flights.

7. In apparatus for material treatment, in combination, a tube having a substantially vertical axis, a first helical trough which spirals around the outside of said tube in a first direction, a second helical trough which spirals within said tube in a direction opposite said first direction, the wall of said tube having an aperture adjacent one end, means for transferring material between one end of said first helical trough and one end of said second helical trough through said aperture, a supporting structure, springs connecting said supporting structure and said helical troughs for permitting vibratory movement of said troughs along a spiral path, and means for imparting vibratory impulses to said helical troughs to induce movement along said spiral path.

References Cited in the file of this patent UNITED STATES PATENTS 2,119,191 Wilkinson May 31, 1938 2,190,072 Keys Feb. 13, 1940 2,464,216 Devol Mar. 15, 1949 2,760,503 Carrier Aug. 28, 1956 2,760,504 Spurlin Aug. 28, 1956 FOREIGN PATENTS 681,704 Great Britain Oct. 29, 1952 943,865 France Oct. 11, 1948 Patent Non z ela ozo December 22 1959 Robert M., Carrier Jr,

It is hereby certified that error" appears in the printed specification oi": the above numbered patent requiring correction and that the said Letters Patent should read as corrected below;

Column 1 line 19 for "pins or flights read pans or flights Signed and sealed this 5th day of July 1960.,

(SEAL) Miami:

KARL H, AXLINE ROBERT C. WATSON Arweting Officer Comissioner oi Patents

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