US2936084A - Alleviating contrivances for silos, drying shafts and the like - Google Patents

Description

y 1960 F. G. H. LAMKE 2,936,084

ALLEVIATING CONTRIVANCES FOR SILOS, DRYING SHAFTS AND THE LIKE Filed April 1, 1957 v 3 Sheets-Sheet 1 F/GZ May 10, 1960 F. e. H. LAMKE 2,936,084

ALLEVIATING CONTRIVANCES FOR SILOS, DRYING SHAFTS AND'THE LIKE Filed April 1, 1957 3 Sheets-Sheet 2 y 1960 F. G. H. LAMKE 2,936,084

ALLEVI TI F/QS W 7L 1 4; 4 :1

-- ALLEVIATING CONTRIVANCES non SIL DRYINGSHAFISANDTHELIKE Gustaf Hugo Lamke, Stockholm, Sweden Application'April'1,'19$7, Serial No. 650,039

. 1- Claim.; 01. 214-17 r fl he present invention relates, to silos, drying shafts and the like, and more particularly to contrivances for taking otherwise contained in 1 such shafts;

[The main object of the invention is to provide an alcated, at the bottom of the; silo or shaft. The upper side) of a beam of the known kind has the form of two planes disposed at right angles to one another, and the space between two;,adj.acfent .be'ams' will thus vary in. a manner such that the free cross section of the shaftis reduced.

Thus, the material passing between the beams fromthe plane through the top to the lower edge'of the beams will have to} move continuously decreasing spaces, "and this restriction of-the free cross section causes angeven sinking of the material passing down the shaft and may cause the formation ofabridges and other disadvantages. It ,such disadvantage, in the first place, that should be' r'e'moved by the" present invention? A further object of the invention is to provide a combination of gratings capable of surely taking up the load of the contents of relatively high silos, shafts and the like.

A still further object of the invention is to provide a contrivance for taking up the load substantially in the lower portion of a shaft to relieve underlying means such as discharging means from the load of materials of any kind consisting of grains or particles of a most varying size, and particularly material in ground condition.

A further object of the invention is to provide gratings for shafts which immaterially restrict the free cross section of the shaft.

According to the invention the contrivance comprises a grating ofinclined plates or the like extending transversely through the shaft, said plates being so arranged that the space between an arbitrary pair of adjacent plates has a constant or nearly constant cross section, or a cross section possibly flaring in the direction of movement of the material passing between said plates. Material passing from the upper edge of such a row to the lower edge thereof consequently moves at a uniform velocity in the various spaces between the plates, inasmuch as-the free cross section is constant, and the invention therefore involves the solution of the problem of attaining an even United States Patent 0 I i I. v H v I of one' 'and'the saniehorizontal sectionthe shaft."

2,936,084 P a tented May 1Q, 9

If all plates in the horizontal portion of the'shaft, wherein the grating is located, are straight and extend in parallel to each other, the load of the superimposed material will give birth to forces'on the plates that have horizontal componentsdirected in the same direction. These' forces consequently tend to displace the plates horizontally toward one side of the shaft. To prevent this, the-plates located on one side of a'middle plane may 0 slope in the one direction to the horizontal plane, while the plates locatedon the other side slope in the opposite direction,- the angles of inclination being then in bothup the load ofgranular-or powdered materials stored or 7 cases preferably equal numerically, so that the horizontal component of theforces acting on one side of said middle ponent of the forces acting on the other side.

Further features of the invention will appear from the following description of a few forms of embodiment illustrated in the accompanying drawings. Fig. 1 shows a" vertical central section through a portion of a shaft provided with .an alleviating contrivance according to the invention, and Fig. 2 shows on a larger scale and in vertical projection afew plates comprised in said contrivance.- Fig. 3 shows, in thesame manner as Fig. l, asecon'd' embodiment of the invention, and Fig.4 shows a corresponding: horizontal projection with the upper gratingpartly removed. Figs. 5 and 6 show a third embodiment corresponding horizontal having the. alleviating contrivance arranged therein. In"

the embodiment according to Figs. l and 2, said contrivanc'e' consists of two rows of plates located above one another, each of said rows'forming a grating. Two arbitrary zadjacentplates 2, 3 in the upper grating extend r irraparallel to each-other, so that a passage 4 is and uniform sinking of the material in the shaft. If

the shaft is provided with such inclined plates evenly distributed along the whole of its cross section, a uniform discharge of the material in the lower opening of the formed between: them, saidpa'ssage broadly taking the form of a 'parallelo'graminthe transverse vertical section shown. The free passage section within each row of such parallel plates is consequently constant from the upper edge 5 of the plates counted to the lower edge 6. The plates extend in each horizontal grating in parallel to one another and bridgethe whole cross section of the shaft.

It is of importance that the upper edge of one plate of a pair of arbitrary adjacent plates projects past the lower edge of the other plate in the pair, that is to say, in a manner such that the projections of the plates on a horizontal plane overlap. Otherwise, the material in the shaft could pass between the plates without being guided by the latter, whereby the sinking of the material in the shaft could become irregular.

The plates take up the load from the superimposed material in the shaft, which at every individual plate may be represented by a force k acting on the upper side of the plate and directed at right angles thereto. By reason of the inclination of the plate, said force tends to displace the plate not only downwardly but sideways as well. Asshown in Fig. 1, the plates, such as the plates 2, 3, located in the upper row on one side of a middle plane of the shaft are inclined in one direction to the horizontal plane, while the plates 7, 8 located on the other side of said diagonal plane slope in the opposite direction. In both cases, the angle of inclination v is numerically the same, for which reason the horizontal component h of the'forces k, which on account of the load of the contents of the shaft on the plates act on one side of the diagonal plane, is balanced by the horizontal component h of the forces k acting on the other side. The sloping plates are kept together by vertical plates 9 extending at rightangles to them, and these latter plates may be anchored with their ends in opposite walls of the shaft. The ends of the plates may also be anchored in the shaft wall or in-ja frame 9 .extending:a'll' around. The frame forms together with the sloping and vertical plates a grating which covers the cross section of the shaft. v

In' the construction according to Fig. 1, the plates '10, 1 1 of the lower grating slope in a direction opposed to that of the plates in the upper grating, but the longitudinal directions of the plates of the two gratings parallel each other. In this construction the lower plate edges of the: upper grating may be located right above the. upper edges of the lower grating, but the downflow of the material between the plates is facilitated,.if there is a small displacement.

The plates are arranged with approxiz surfaces. They are kepttogether by radial bracingplates mately the same pitch in the grating located above one another, but the-plates of the one grating are displaced by a fraction of the pitch of the plates in the other grating. This is elucidated in Fig. 2, where the :pitchof the plates is denoted by a and the plates 10, 110i the lower row are displaced by %a relatively to the plates 2, 3 of the upper row.

Figs. 34 show an embodiment, wherein two horizontal gratings 12, 14 above one another the plates of the upper grating 12 extend with their longitudinal direction at right; angles to the plates of the lower grating 14. Here'- by afurther distribution of the load is obtained. Both in the upper and in the lower grating the plates are inclined on one side of the middle'plane in a' direction opposed to that of the plates on the other side, whereby the resultant of the horizontal components of the load on the various plates becomes equal to zero.

It should be noted that the shaftwall projects forwardly 17, at least some of which extend into'acentral conical member 18. This member may be connected to a supporting spider 19 through a central rod 20 The spider is located at a distance above the grating. H

What I claim is:

A granular material load supporting apparatus comprising a cylindrical shaft having vertical walls, a horizontal grating traversing said shaft intermediate the upper and lower ends thereof, said grating consisting of a central conical member,-a' plurality of radially-spaced circular plates concentrically mounted about said central conical member and sloping. radially-outwardly front their top edges to their bottom edges, one of two adjacent plates having itsftop edge extending horizontally past the lower edge of the other plate so that the projectionsof the plates on a horizontal plane will overlap, any" two plates forming therebetween a space having a constant crosssection, and radially-arranged bracing plates connecting said circular plates to said-central conical member; spider means in said shaft above said grating; and means connecting the central conical portion of said grating to said spider means, said shaft having ahorizonta'l cross-sectional area below said grating which is at least as great as the horizontal cross-sectional area above the grating;

References Cited in the file of this patent" UNITED STATES PATENTS s79,273 Kinealy Feb. 18. 1908 1,906,408 Persons May 2, 1933;

2,783,898 Ardern et all, Mar. 5, -7"

2,8 54,155 Payne Sept. 30, 1958 it FOREIGN PATENTS I 487,982 Canada Nov. 11', 19 52" mama.

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