GB2189286A - Improvements in or relating to bunkers - Google Patents

Abstract

A bunker 1 is provided with a base 4 formed in two parts 6, 8 symmetrically disposed about a central longitudinal discharge outlet 10. The parts 6, 8 are pivotted along their edges adjacent an outlet and are resiliently biased through the agency of spring units 14. Two opposing containment walls 11 are pivotted along their top edges and their lower ends are in sliding contact with the base parts 6, 8. Loading of material into the bunker energises the spring units 14 which dissipate their energy by causing the material continually to flow towards the discharge outlet. <IMAGE>

Description

SPECIFICATION Improvements in or relating to bunkers This invention concerns improvements in or relating to bunkers.

In particular the present invention has reference to means forfacilitating the discharge of discrete material from a bunker.

One of the main problems associated with the storage of such material in essentially flat-bottomed bunkers is that of displacing the material from all regions ofthe bunker into a conveyor or outletfor discharge. It has been found that as much as seventy percent of material in afull bunkerwill remain undisturbed and will notflowwhen required. This condition arises due to a combination offactors. For example,theassumption by the material of natural angles of repose around the discharge outlet results in large volumes of material remaining static within the bunkerwith little possibility of movement unless external assistance is provided.Moisture content of the material can also exacerbate this problem as can bridging which leaves voids in the vicinity of the discharge outlets thus preventing free flow of material from the bunker.

One solution already proposed involves the use of inflatable membranes which linethebunkerwalls and base circumjacentthe discharge opening. As and when necessary, the membranes are inflated thus causing movement of the material towards the opening. Although this arrangement is effective, it does require a pressure fluid source, e.g.

compressed air, in order to function. Furthermore, the membranes are liable to wear particularly when hard and/or abrasive material is to be stored.

An object of the present invention is to provide an improved bunker having a means of assisting material flow towards a discharge opening thereof.

According to the invention, a bunkerfor storing discrete material includes a base and containment walls upstanding therefrom, an inlet and a discharge outlet, at least a part of the base and a containment wall being movable underthe action of a resilent bias whereby in use material flowtowards the discharge outlet is assisted by the said bias.

Conveniently, the discharge outlet is located centrally of the base which in the case of a rectangularly shaped bunker, may be in two parts one disposed either side of the outlet and pivotted adjacent thereto. The outlet may be in the form of a longitudinal slot in communication with a screw conveyor situated therein or therebelow.

Each part of the base is provided with at least one resilientbias,forexampleaspring,arrangedto elevate the associated part such that in use material lying thereon will gravitate towards the discharge outlet.

Advantageously, an opposing pair of containment walls are resiliently biased and are pivotted at or below the free upper edges remote from the base, their lower edges contacting the respective parts of the base either side of the discharge outlet, whereby there is an interaction between the walls and the base such that they can move in unison. The opposing walls may also be provided with their own resilient bias.

The bunker is advantegously mounted a structure providing appropriate abutments for the resilient bias.

The resilient bias for the base parts may comprise three concentric springs, primary secondary and tertiary, each disposed within a sleeve telescoping into its neighbouring spring sleeve.

By way of example only, a bunker according to the invention is described belowwith referencetothe accompanying drawings in which: Figure 1 is an isometric view of the bunker; and Figure 2 is a diagrammative cross-section of an half of the bunker.

Referring to the drawings, a bunker for storing discrete material, e.g. coal, is illustrated at 1 and is mounted in a framework 2 shown in ghosted outline.

The bunker 1 is of rectangularform and has a base4 formed in two parts 6,8 each pivotally mounted along the edge adjacent a central discharge slot 10 adapted to receive a conveyor screw (not shown), the pivots being received in the end walls (not shown for the sake of clarity).

The bunker 1 has both end walls and opposing side walls 11 upstanding from the base 4, each wall 11 being hinged along its top edge to the framework 2 and being in sliding contact at is lower edgewith the top surface of a respective base part 6, 8. In the embodiment shown, the lower edge 12 is of curved form to ensure a smooth sliding contact; however, the lower edge may be formed of tubing or equivalent, for example rollers.

A resilient bias is provided for the base 2 and comprises a plurality of spring units 14 arranged beneath the base parts 6, 8, each unit being telescopic with concentric primary, secondary and tertiary springs therewithin and having appropriate spring rates to provide controlled compression and expansion. Similar spring units may be provided for the walls 10. The spring units all operate between the base parts and/or the walls and the framework.

In operation, discrete material,for example coal, is transferred into the bunker 2 through its inlet, i.e.the open top, and the gradually increasing weight deflectsthe base parts 6, 8 downwardly againstthe resilient bias and also forces the walls 11 outwardly.

As the coal is delivered into the bunker 2, the tertiary spring of the spring units 14 contracts into the secondary spring and the secondary spring contracts into the primary spring. In this way, when fully loaded the base 2 lies at a shallow angle with respect to the horizontal thus maximising the bunker capacity. The coal will feed gravitationally into the discharge slot 10 until the material angle of repose of the coal is achieved. Before this angle is reached, the spring units 14 are so designed as to raisethe base 2 allowing the coal to be continually fed into the discharge slot 10. The potential energy ofthe coal operates the base and side walls and this affords an automatic method of assisting material from a bunkerwith minimum supervision.

Claims (10)

1. A bunkerfor storing discrete material includes a baseandcontainmentwallsupstandingtherefrom, an inlet and a discharge outlet, at least a part ofthe baseandacontainmentwallbeing movable under the action of a resilient bias whereby in use material flow toward the discharge outlet is assisted by said bias.

2. Abunkeraccordingto claim 1 inwhichthe discharge outlet is located centrally ofthe base and is formed of a slot.

3. A bunker according to claim 2 in which the bunker is rectangularly shaped and the base is in two parts symmetrically disposed about the discharge outlet, each part being pivotted along its length adjacent to the outlet.

4. A bunker according to claim 2 or3 in which a screw conveyor is situated in association with the slot.

5. A bunker according to claim 3 in which each partofthe base is provided with atleastone resilient bias.

6. A bunker according to claim 4 in which the or each resilient bias is in the form of a telescopicspring unit having primary, secondary and tertiary springs each arranged in a confining sleeve.

7. A bunker according to claim 3 in which a pair of opposing containment walls is resiliently biased and each wall is pivotally mounted along its relatively upper edge, its lower edge being in sliding contact with the upper surface of a respective base part.

8. A bunker according to claim 6 in which the lower edge of each opposing containmentwall is formed of tubing.

9. Abunkeraccordingto anyoneofthe preceding ciaims in which a mounting framework is provided within which the bunker is located.

10. A bunker for discrete material substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.