US3837092A

US3837092A - Apparatus for cooling or drying pourable material

Info

Publication number: US3837092A
Application number: US00355664A
Authority: US
Inventors: O Mayer
Original assignee: Georg Fischer AG
Current assignee: Georg Fischer AG
Priority date: 1972-05-01
Filing date: 1973-04-30
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24
Also published as: DE2312440B2; FR2183074A1; CH555283A; DE2312440A1; GB1424274A; IT984236B; FR2183074B1

Abstract

Pourable material is introduced into the upper end of a tank and moves downwardly about a centrally arranged feed pipe perforated along its length for introducing a gaseous medium into the material, and the material is removed from the bottom of the tank. Horizontally arranged, vertically spaced ring discs are located outwardly from the feed pipe and inwardly from the tank so that the downwardly moving pourable material enters between adjacent ring discs and forms a frusto-conically shaped layer of material. By varying the cross sectional size of the openings in the feed pipe and/or varying the size and/or spacing of the ring discs the treatment of the pourable material by the gaseous medium can be varied.

Description

United States Patent 1 Mayer Sept. 24, 1974 APPARATUS FOR COOLING OR DRYING POURABLE MATERIAL Inventor: Otto Fritz Mayer, Schaffhausen,

Switzerland Assignee: Georg Fischer Aktiengesellschaft,

Schaffhausen, Switzerland Filed: Apr. 30, 1973 Appl. No.: 355,664

Foreign Application Priority Data May 1, 1972 Switzerland 6474/72 US. Cl 34/168, 34/173, 34/174 Int. Cl F26b 17/12 Field of Search 34/165-179, 34/181, 187, 64-66 References Cited UNITED STATES PATENTS 10/1925 Sherban 34/174 11/1947 Allinson 34/173 11/1958 Lellep 34/174 3,025,043 3/1962 Ruelle et al 34/167 Primary Examiner-Kenneth W. Sprague Assistant Examiner james C. Yeung Attorney, Agent, or Firm-Toren, McGeady and Stanger E 5 7 ABSTRACT Pourable material is introduced into the upper end of a tank and moves downwardly about a centrally ar-' ranged feed pipe perforated along its length for introducing a gaseous medium into the material, and the material is removed from the bottom of the tank. Horizontally arranged, vertically spaced ring discs are located outwardly from the feed pipe and inwardly from the tank so that the downwardly moving pourable material enters between adjacent ring discs and forms a frusto-conically shaped layer of material. By varying the cross sectional size of the openings in the feed pipe and/or varying the size and/or spacing of the ring discs the treatment of the pourable material by the gaseous medium can be varied.

16 Claims, 4 Drawing Figures PAIENTEDSEPZMW 3.637; 092

' sum 3 or 4 Fig. 3

SUMMARY OF THE INVENTION The present invention is directed to an apparatusfor cooling or drying at pourable material or bulk material, such as a pretreated foundry sand, by means of a gaseous medium traversing the pourable material, and, more particularly, it is directed to the arrangement of the apparatus including a tank into which thematerial is introduced at its upper end through a tubular passageway so that it flows downwardly about a feed pipe containing openings along its length for introducing the gaseous mediuminto the material and, further, it concernsthe arrangement of horizontally arranged, vertically spaced ring discs located outwardly from the feed pipe and'inwardly from the tank. At the lower end of the tank a device is arranged for discharging the treated pourable material.

Among the-various apparatus known for cooling and drying pourable material is a sieve drum centrifuge which includes a central feed drum for the material which is provided with conveyor elements. The centrifuge is concentrically enclosedby a'housing and circulating drying air enters-the centrifuge in the axial direction and issues-radiallyfrom it passing through the material layer which adheres to the wall of the centrifuge. The operation of such an apparatus is difficult, however, because the-material adhering to the wall of the centrifuge is aerated only at those locations where openings are-provided-for the drying air. Further, because the bearings of the centrifugal drum are in the range of the material being treated, they are subjected to considerable'wear.

In another known apparatus, a tank is provided into which the material is supplied at its upper end and is removed at its lower end and the tank contains channels which have the form of parallel screw turns about a common axis and eachchannel consists, in the longitudinal direction, of two parts elastically connected to gether with each part having a separate drive and a device for aerating the material is located within the tank. The aeration of the bulk material depends, to a great extent, on the sliding capacity of the material, accordingly, a uniform passage of the material through the tank is not ensured when the material is sticky. Furthermore, where movable parts are located within the pourable material, particularly when the material is foundry sand, there is excessive wear in such parts.

Still another known apparatus is a ring disc dryer which contains rotating discs formed of segmentshaped plates which are arranged side-by-side on a circular ring with at least two and not more than three charging and transfer zones being arranged for charging the material onto the uppermost disc and for transferring the material from one disc to another. The ring discs form an interior in which several tu'rbofans are provided for air circulation. A disadvantage of this arrangement is that the moving parts are exposed to excessive wear in the range of the pourable material.

Therefore, it is the primary object of the present invention to overcome the problems and disadvantages experienced in the known apparatus by utilizing a tank for the flow through of the material to be treated which does not contain any moving parts in contact with the material. Further, the structure within the interior of the tank is arranged so that a vertically extending annular cavity is provided outwardly from the material and inwardly from the tank wall to assure a constant flow of the gaseous medium through the pourable material.

In accordance with the present invention, horizontally arranged, vertically spaced ring discsare mounted in fixed positions within the tank encircling the feed pipe which supplies the gaseous medium. The inner edges or peripheries of the discs are-spaced outwardly from the feed pipe so that the downwardly flowing material enters between adjacent ones of the discs and forms a frusto-conically shaped layer with itsouter surface spaced inwardly from the tank wall. ;As a.res ult, the gaseous medium flowing between the two adjacent ring discs exits from the surface of the material into an open space outwardly of the ringdiscs. The treatment of the pourable material over the height of the tank can be varied by varying the cross sectional area of the openings in the feed pipe, by varying the spacing of-the ring discs and by varying the dimensions of the ring discs.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure.

For a better understanding of the invention, its operating advantages and and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a vertical sectional view of one embodiment of the present invention;

FIG. 2 is a vertical sectional view, similartoFIG. 1 of another embodiment of the present invention;

FIG. 3 is a vertical sectional view similar to FIGS. 1 and 2 of still another embodiment of the present invention; and

FIG. 4 is a vertical sectional view similar to FIGS. 1 to 3 showing'still another embodiment of the present invention.

DETAILED DESCRIPTION OF THEINVENTION In FIG. 1 a vertically arranged treatment tank l is shown with a tubular shaped feed passageway 2 connected to its upper end for introducing a pourablematerial into the tank. Concentrically arranged about the vertical axis of the tank is a frusto-conically shaped feed pipe 4 which extends downwardly through the tank and has circular openings 5 for supplying a gaseous medium into the tank for flow through the pourable material. The feed pipe extends for substantially the full height of the tank. Extending about the feed pipe are horizontally arranged vertically spaced ring discs 6 fixedly secured within the tank. The discs are arranged about the feed pipe from its upper to its ,lowerend. The inner periphery of each annular or ring disc is spaced outwardly from the feed pipe and, similarly,,theouter peripheryof eachring disc is spaced inwardly from the At the lower or outlet end 7 of the tank, a device 8 is arranged for discharging the pourable material after its passage downwardly through the tank. A. variable drive is provided for the discharge device 8 and the drive can be operated from a central control plant, not shown, over a control line 18 and a control device 16. In the lower end of the tubular passageway 2, above the openings in the feed pipe 4, a level gauge 17 is arranged which is connected over a control line 19 to the central control plant and also controls the conveyor for supplying the pourable material. At the upper end of the tank an exhaust pipe 12 is arranged in communication with the upper end of the annular outer cavity or space for withdrawing the gaseous medium after its passage through the pourable material. A feed line 13 extends into the tubular passageway 2 and is connected to the upper end of the feed pipe 4 for supplying the gaseous medium and a valve 14 is located in the feed line and it is actuated by a control device connected to the central control plant. I

In FIG. 1, due to the downwardly and inwardly tapering configuration of the feed pipe 4 the spacing between the inner periphery of the ring discs 6 and the feed pipe 4 increases in the downward direction. Further, because of its frusto-conical shape, the number of openings 5 in the feed pipe 4 between adjacent ones of the ring discs 6 decreases in the downward direction.

In FIGS. 2, 3 and 4 different embodiments of the apparatus are shown, as compared to FIG. 1, however, similar parts are designated with the same reference numerals. In FIG. 2 a cylindrically shaped feed pipe 21 extends downwardly through the tank and contains rectangularly shaped openings 5' spaced along its length between each pair of adjacent ring discs. Further, as can be noted in FIG. 2, the outside diameter of the ring discs increases in the downward direction while the spacing between the discs is maintained the same. In FIG. 3 a cylindrically shaped feed pipe 23 extends downwardly through the tank 1, however, its circular openings 5 decrease in cross sectional area in the downward direction of the feed pipe. Further, in the embodiment of FIG. 3 the ring discs 6 are uniformly dimensioned and spaced. In FIG. 4 the feed pipe 24 is formed of a plurality of slightly overlapping frustoconically shaped rings 25 with the smaller diameter ends of the rings spaced upwardly above the larger diameter ends. As can be seen, the larger diameter end of each ring extends downwardly below and about the smaller diameter end of the next lower ring. Further, the end diameters of the overlapping rings 25 are arranged so that openings are provided between their respective outer and inner surfaces. Further, in FIG. 4, the ring discs 22 increase in outside diameter in the downward direction and the spacing between adjacent ring discs also increases in the downward direction.

Due to the extremely simple design of the apparatus, other variations can be provided, in addition to those shown in the drawing, depending on the type and configuration of the material being treated, since only the ring discs and/or the feed pipe need be changed. Further, the shape of the ring discs and of the openings in the feed pipe can be varied from the circular and rectangular shapes illustrated. In the operation of the apparatus embodying the invention, a pourable material, for example, a pre-treated foundry sand, is fed, from a feeding device, not shown, through the tubular passageway 2 into the tank Landthe sand passes downwardly through the inner annular space 11 gradually filling the space about the feed pipe. As the height of the sand increases a frusto-conically shaped layer of the sand is formed between each pair of adjacent ring discs. The radially outer surface of each layer has a sloping or frusto-conical shape 9. When the level of the material flowing downwardly into the tank finally reaches the level gauge 17, a control impulse is emitted from the gauge to actuate the valve in the gaseous-medium feed line 13 and to start the discharge device 8; Between the surface of the feed pipe 4 and the frustoconically shaped surface 9 of the layer of material between adjacent ring discs, a certain flow path is formed for the gaseous medium flowing through the material and this flow path may be variable over the height of the tank in consideration of the material being treated. The gaseous medium escapes from the material along its laterally disposed frusto-conically shaped surface 9 and enters the outer cavity or space 10 at a very low flow velocity.

The treated material is fedby the discharge device 8 to a conveyor means, not shown, for example, a conveyor belt or conveyor trough. It has been found to be expedient to provide the discharge device 8 with a variable discharge rate to obtain the optimum treatment of the pourable material 3.

Among the advantages achieved with these various embodiments of the apparatus formed according to the present invention, are, in particular, that no moving parts are used and that the gaseous medium after traversing the material issues into a space bounded inwardly by the material and outwardly by the inner surface of the tank without causing damage to any portion of the apparatus.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. Apparatus for cooling or drying a pourable material, such as a pre-treated foundry sand, by passing a gaseous medium through the pourable material, comprising a vertically extending tank, a tubular passageway connected to the upper end of said tank for supplying the pourable material into said tank, a vertically arranged feed pipe positioned within said tank and aligned below said tubular passageway, said feed pipe having a plurality of openings therethrough at spaced positions along its length, said feed pipe arranged to receive the gaseous medium and to distribute it through its openings into the pourable material, ring discs positioned within said tank and extending transversely of the axial direction of said feed pipe, an outlet for the material to be treated located in the lower end of said tank, and a discharge device located below the outlet for the material to be treated for discharging the pourable material after its downward passage through said tank, wherein the improvement comprises that said feed pipe is centrally positioned within said tank and the lower end of said feed pipe is located in the lower end of said tank above said discharge device, said ring discs are horizontally arranged and extend about said feed pipe and are spaced apart in the vertical direction, said ring discs are fixedly mounted within the said tank and each said ring disc has an inner annular periphery .the outer peripheries of said discs and the inner surface of said tank whereby the pourablematerial introduced through said tubular passageway flows downwardly about said feed pipe through said inner space and into the spaces between adjacent said ring discs for forming frusto-conically shaped layers of the pourable material on said ring discs, the openings of said feed pipe are arranged to direct the gaseous medium between adjacent said ring discs and also out of the bottom of said feed pipe, and a gaseous medium outlet opening located in the upper end of said tank communicating with the upper end of said annular shaped outer space so that the gaseous medium flows outwardly through the pourable material between adjacent said ring discs and into said outer space for flow upwardly therethrough to said gaseous medium outlet openings, and means associated with said feed pipe for affording variable flow condi tions of the gaseous medium through the pourable material.

2. Apparatus, as set forth in claim 1, wherein the cross sectional area of the openings in said feed pipe located between adjacent said ring discs varies 'over the length of said feed pipe.

3. Apparatus, as set forth in claim 2, wherein said ring discs are variably spaced apart for varying the cross sectional area of flow through the pourable material between adjacent said ring discs.

4. Apparatus, as set forth in claim 1, wherein the spacing between the inner periphery and outer periphcry of said ring discs varies between said ring discs and affords variable length of flow paths for the gaseous medium flowing between adjacent said ring discs.

5. Apparatus, as set forth in claim 1, wherein said feed pipe located within said tank is frusto-conical and tapers inwardly as it extends downwardly toward the lower end of said tank.

6. Apparatus, as set forth in claim 1, wherein said feed pipe located within said tank is cylindrically shaped.

7. Apparatus, as set forth in claim 1, wherein the openings in said feed pipe all have the same cross sectional area.

8. Apparatus, as set forth in claim 7, wherein the openings in said feed pipe are circular.

9. Apparatus, as set forth in claim 7, wherein the openings in said feed pipe are multisided.

10. Apparatus, as set forth in claim 1, wherein the openings in said feed pipe are of different-cross sectional areas.

11. Apparatus, as set forth in claim 10, wherein the openings in said feed pipe have decreasing cross sectional areas in the downward direction of said feed pipe.

12. Apparatus, as set forth in claim 1, wherein the surface of said feed pipe within said tank is formed of a multiplicity of frusto-conically shaped rings secured together and arranged in an overlapping relationship with the smaller diameter end of each ring being lo cated upwardly above the larger diameter end and with the larger diameter end of each ring extending down wardly below and spaced outwardly from the smaller diameter end of the next lower said ring.

13. Apparatus, as set forth in claim 1, wherein each of said ring discs has the same dimensions.

14. Apparatus, as set forth in claim 1, wherein adjacent said ring discs are spaced the same distance apart.

15. Apparatus, as set forth in claim 1, wherein the inner periphery of each said ring disc is aligned below the inner surface of said tubular passageway.

16. Apparatus, as set forth in claim 1, including means for variably driving said discharge device.

Claims

1. Apparatus for cooling or drying a pourable material, such as a pre-treated foundry sand, by passing a gaseous medium through the pourable material, comprising a vertically extending tank, a tubular passageway connected to the upper end of said tank for supplying the pourable material into said tank, a vertically arranged feed pipe positioned within said tank and aligned below said tubular passageway, said feed pipe having a plurality of openings therethrough at spaced positions along its length, said feed pipe arranged to receive the gaseous medium and to distribute it through its openings into the pourable material, ring discs positioned within said tank and extending transversely of the axial direction of said feed pipe, an outlet for the material to be treated located in the lower end of said tank, and a discharge device located below the outlet for the material to be treated for discharging the pourable material after its downward passage through said tank, wherein the improvement comprises that said feed pipe is centrally positioned within said tank and the lower end of said feed pipe is located in the lower end of said tank above said discharge device, said ring discs are horizontally arranged and extend about said feed pipe and are spaced apart in the vertical direction, said ring discs are fixedly mounted within the said tank and each said ring disc has an inner annular periphery spaced outwardly from said feed pipe and an outer annular periphery spaced outwardly from the inner periphery and inwardly from the interior surface of said tank so that a vertically extending annular shaped inner space laterally encloses said feed pipe inwardly of the inner peripheries of said ring discs and a vertically extending annular shaped outer space is located between the outer peripheries of said discs and the inner surface of said tank whereby the pourable material introduced through said tubular passageway flows downwardly about said feed pipe through said inner space and into the spaces between adjacent said ring discs for forming frusto-conically shaped layers of the pourable material on said ring discs, the openings of said feed pipe are arranged to direct the gaseous medium between adjacent said ring discs and also out of the bottom of said feed pipe, and a gaseous medium outlet opening located in the upper end of said tank communicating with the upper end of said annular shaped outer space so that the gaseous medium flows outwardly through the pourable material between adjaCent said ring discs and into said outer space for flow upwardly therethrough to said gaseous medium outlet openings, and means associated with said feed pipe for affording variable flow conditions of the gaseous medium through the pourable material.

2. Apparatus, as set forth in claim 1, wherein the cross sectional area of the openings in said feed pipe located between adjacent said ring discs varies over the length of said feed pipe.

4. Apparatus, as set forth in claim 1, wherein the spacing between the inner periphery and outer periphery of said ring discs varies between said ring discs and affords variable length of flow paths for the gaseous medium flowing between adjacent said ring discs.

10. Apparatus, as set forth in claim 1, wherein the openings in said feed pipe are of different cross sectional areas.

12. Apparatus, as set forth in claim 1, wherein the surface of said feed pipe within said tank is formed of a multiplicity of frusto-conically shaped rings secured together and arranged in an overlapping relationship with the smaller diameter end of each ring being located upwardly above the larger diameter end and with the larger diameter end of each ring extending downwardly below and spaced outwardly from the smaller diameter end of the next lower said ring.