GB2107276A

GB2107276A - Extraction apparatus for silos

Info

Publication number: GB2107276A
Application number: GB08226064A
Authority: GB
Inventors: Dr Theodor Hesse; Hans Barkmeyer
Original assignee: Engelbrecht & Lemmerbrock; Engelbrecht and Lemmerbrock GmbH and Co
Current assignee: Engelbrecht & Lemmerbrock; Engelbrecht and Lemmerbrock GmbH and Co
Priority date: 1981-09-19
Filing date: 1982-09-13
Publication date: 1983-04-27
Also published as: GB2107276B; IT1153193B; FR2513230A1; IT8223319A0; BE894393A; DE3137325C2; SE8205347D0; NL8203550A; SE8205347L; ES515734A0; DE3137325A1; ES8306352A1

Abstract

This invention relates to apparatus for extracting bulk goods from a silo 1 of the kind which has a bearer 5 comprising clearing members 6 and being rotarily entrainable and lowerable, said clearing members conveying and bulk material from the momentary top layer of the bulk material to central vertical gravity shaft 2 having a bottom removal facility. The invention consists in that a funnel 8 starting from the top surface of the material and having a tip downwardly directed towards the axis of the shaft is produced at the gravity shaft 2 by a clearing member or members 6a of different configuration. <IMAGE>

Description

SPECIFICATION Extraction apparatus for silos The present invention relates to apparatus for extracting bulk goods, being industrial bulk goods in particular, from a silo from which the momentary top layer of the material is conveyed by means of bearers comprising clearing members and said bearers being rotatable and lowerable and operating radially inwards from the outside, to a stationary central gravity shaft preferably formed by annular plates arranged one above another with mutual spacing from and parallel to each other and having a bottom transfer or removal facility utilising a transverse conveyor.

It is known that bulk goods may be extracted from silos by conveying the material from the momentary top layer by means of rotating and lowerable bearers comprising clearing members to a central vertical so-called ring-plate column acting as a gravity shaft, from which it is fed to optional locations at the lower extremity by means of a transverse conveyor. To this end, the ring-piate column comprises ring plates installed one above another with mutual spacing from and parallel to each other, the annular width of which is so selected as to result in an angle of repose of material which does not extend into the shaft formed by the ring plates.

The clearing members mounted on the bearers and conveying inwards from the outside have hitherto worked uniformly deeply into the top layer of the material which they feed to the gravity shaft formed by the column of plates, the material accumulating to some slight extent before the plate column. The material fed to the gravity shaft may consequently penetrate into the gravity shaft substantially only via the gaps between a few ring plates so that the bottom transverse conveyor is only partially loaded.

It is an object of the invention to enable a substantially increased quantity of material to be fed to a gravity shaft in the form of a column of plates for preference, as compared to that which it receives as a result of the known arrangement of clearing members.

According to the invention, this problem is resolved in that in the apparatus as hereinbefore referred to, the rotating bearers are each provided with at least one clearing member right at or close to the periphery of the gravity shaft which, at the shaft, produces a funnel of material starting from the surface of the material and having its tip downwardly directed towards the axis of the shaft. Due to this arrangement, an optional number of open gaps is made available between the ring plates for passage of the material into the gravity shaft, not only above but also below the level of the material, and an increased clearance of the top layer of the material on the one hand, and an adaptation of the feed of material into the gravity shaft to the high performance of the transverse bottom conveyor receiving the material on the other hand, are possible thereby.The overall efficiency for extraction of bulk goods from silos, in particular of industrial bulk goods, is considerably raised thereby.

In order that the invention may be more clearly understood, an embodiment of silo extraction device will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a diagrammatical axial section through the upper section of a silo which is filled with and to be cleared of industrial bulk goods, and Figure 2 shows a cross-section along the line Il-Il of Figure 1.

Referring now to Figures 1 and 2, a circular silo 1 is shown which provided with a stationary central gravity shaft 2 which is constructed as a so-called ring-plate column, meaning that the individual ring plates 3 installed one above another with mutual spacing from and parallel to each other form the gravity shaft, the width of the rings being so selected that an angle or repose or slope 4 of the industrial bulk material loaded in and shown in dash-dotted lines is formed below each ring plate, which does not however extend into the actual gravity shaft 2.

For clearing the silo radiai bearers 5 entrainable in rotation and lowerable above the level of the bulk material have installed on them clearing members which comprise freely rotatable entraining discs 6 whose peripheries engage into the momentary top layer of the material, which during the rotation of the gradually lowerable bearers 5 convey the material from the top layer to the gravity shaft 2 and into the latter via the gaps between several ring plates 3. In doing so, the material may accumulate in some degree against the gravity shaft in particular circumstances and produce a small upwardly directed slope.

The rotating clearing members are in a position however to supply the gravity shaft with considerably greater quantities of material corresponding to the top layer shown dotted, and the gravity shaft can receive such larger quantities of descending material which may be removed by a bottom transverse conveyor 7 (Fig. 2 only). To accomplish this purpose, the clearing members are arranged to engage more deeply into the top layer of material, so that the material conveyed to the gravity shaft radially from the outside is piled up in upward direction against the gravity shaft.Complementarily, those clearing members 6a situated right at the periphery of the shaft 2 or close thereto have their diameter or height selected to be of such magnitude and are so arranged in accordance with the invention, that right at the shaft they produce a funnel 8 of material starting from the surface of the material, the tip of which is downwardly directed towards the axis of the shaft. These clearing members 6a complentarily also handle the material upwardly piled up against the shaft.

It is understandable that a considerably greater number of gaps is available between the ring plates 3 for traversal by the material supplied by the clearing members 6, 6a due to this construction. Considerably increased quantities of bulk material are thereby fed to the gravity shaft and easily received for onward transmission at the bottom extremity by the transverse conveyor 7.

Although the tools perform less work, the clearing performance for the silo is considerably improved thereby.

Instead of incident entraining discs 6 installed in rotatable manner to act as clearing members, it is also possible to utilise cutters engaging in the top layer of material to convey material radially to the shaft, the cutter or cutters situated right at the shaft 2 again having their height selected to be of such magnitude as to produce the funnel 8 downwardly directed from the surface of the material and as to deal with the upwardly piled up quantity of material to force the same into the shaft.

The clearing members may alternatively comprise both entraining discs 6 and cutters and several clearing members 6a situated close to the gravity shaft may also be mounted on each bearer 5 whilst being graded in diameter and/or height to increase the funnel, e.g. in the case of a silo of large diameter. Instead of the entraining discs 6 or cutters it is alternatively possbile to utilise scraper belts which feed the material to the gravity shaft above the members 6a producing the funnel.

Claims

1. Apparatus for extracting bulk goods, in particular industrial bulk goods, from a silo from which the momentary top layer of the material is conveyed by means of bearers comprising clearing members and said bearers being rotatable and lowerable and operating radially inwards from the outside to a stationary central gravity shaft preferably formed by annular plates arranged one above another with mutual spacing from and parallel to each other and having a bottom transfer or removal facility utilising a transverse conveyor, wherein the rotating bearers are provided, at least closeiy adjacent to the periphery of the gravity shaft, with at least one clearing member which, at said shaft, produces a material funnel starting from the surface of the material and having its tip downwardly directed towards the axis of the shaft.

2. Apparatus as claimed in claim 1, wherein the or each clearing member forming the tunnel of material comprises an etraining disc or cutter which has a greater height or a greater diameter than the other clearing members which are of lesser height or lesser diameter.

3. Apparatus as claimed in claim 1, wherein the or each clearing member producing the funnel of material comprises an entraining disc or cutter which is mounted at a lower level on the rotating bearer than the other clearing member or members removing the top layer of the material.

4. Apparatus as claimed in claim 1, 2 or 3, wherein several of said clearing members are graded in diameter and/or staggered in height and are arranged to produce the funnel of material.

5. Apparatus as claimed in any of claims 1 to 4, wherein both entraining discs and cutters are provided for said bearers.

6. Apparatus as claimed in any of claims 1 to 4, wherein the entraining discs and/or cutters producing the funnel have associated with them clearing members comprising scraper belts.

7. Apparatus for extracting bulk goods, substantially as hereinbefore described with reference to the accompanying drawings.