GB2174373A

GB2174373A - A bulk material bunker for underground operations

Info

Publication number: GB2174373A
Application number: GB08609353A
Authority: GB
Inventors: Josef Muller
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-04-24
Filing date: 1986-04-17
Publication date: 1986-11-05
Also published as: DE3514722C2; GB2174373B; GB8609353D0; DE3514722A1

Abstract

A bulk material bunker for underground operations. more particularly in a perpendicular circular bunker, whose bulk material chamber is formed by walling 14 of a shaft 15 and is charged with the bulk material from above preferably with the aid of a spiral chute 11 which reaches as far as a bunker outlet and through which the bulk material arrives in the bulk material chamber of the bunker, in which is a climbing and ventilation shaft 33 having hollow facing, there being a recess 48 for the climbing and ventilation shaft 22 arranged on the bunker wall 14 and the recess 48 is in a part of the facing 52 of the shaft 50 which, together with the facing 44 of the recess 48 and with the shaft walling 45 directed to the latter, forms an airway into which the climbing shaft 50 is integrated. <IMAGE>

Description

SPECIFICATION A bulk material bunker for underground operations The invention concerns a bulk material bunker for underground operations, more particularly a perpendicular circular bunker whose bulk material chamber is formed by the walling of a shaft and is charged with the bulk material from above, with the aid of a spiral chute, which reaches as far as a bunker outlet and through which the bulk material arrives in the bulk material chamber, out of which is a climbing and ventilation shaft having hollow facing.

Bulk material bunkers in underground mining serve as intermediate stores and are disposed either between two consecutive continuous conveyors or at the intersection of a continuous conveyor and a conveying device travelling to and fro, which can for instance be developed as conveyance by cars. The invention concerns more particularly the first-named arrangement and is preferably applicable in the form of bulk material bunkers which extend over a relatively small vertical interval in relation to their cross-section. Preferably in these cases the bulk material bunker is a circular bunker, because in this way the relationship of rock flow and volume of the bulk material bunker is optimal and in any case more favourable than with square cross-sections.

Such bulk material bunkers can be fitted in the main line and are then served directly by the conveying device connected on the input side, or they are disposed in a shunt and are then acted upon by a conveying device that can be bypassed with the conveying device connected on the input side. The harmonisation of the conveying depends on the fact that, according to conveying capacity, either the bunker chamber is wholly or partially filled if the conveying capacity of the conveying device connected at the output side is exceeded, or the conveying proceeds through the bunker if the quantity conveyed out of the bunker is equal to or less than the conveying capacity of the conveying device coupled at the output side.

The fitting of a spiral chute in the bunker prevents the free fall of the bulk material through the bunker, which happens with tip bunkers. The grain disintegration, causing a reduction in proceeds, and the associated dangerous development of dust, which arise in particular as the product is conveyed, can be prevented with the inbuilt spiral chute. The latter automatically brings about the equalisation function of the bulk material bunker as described, because the material conveyed, when exceeding the fill cross-section of the spiral chute, fills the bunker chamber spontaneously and is drawn away out of the latter through the bunker outlet.Spiral chutes of this kind must of course be built in such a way that they are not carried away, in the course of removal of the bulk material from the bunker chamber, by the suction that the bulk material exerts in this process on stationary parts in the bunker which are disposed in or near to the centre of the bunker.

The fitting of a climbing-shaft in the bulk material bunker serves on the one hand as a means of enabling the distances between the conveying devices coupled one after another to be directly overcome, that is to say a means of shortening the path for passenger transport between the discharge of the continuous conveyor coupled at the input side and the infeed of a conveying device on the output side. On the other hand, such a climbingshaft also facilitates the surveillance of the bulk material bunker as well as the clearing of stoppages if necessary. For this purpose, frequent peepholes are provided in the casing of the climbing-shaft, which can be closed at any time with a slide or a flap.The installation of a ventilation shaft, by contrast, mostly becomes necessary in order to ensure the passage of air when the bunker is full and when the bunker cross-section is then no longer passable for ventilation, at least in so far as the latter is necessary for the supply of air to the area in which the intake and outlet of the conveying devices coupled on the input and output sides are accommodated. Furthermore, the ventilation shaft has the function of supplying air to the climbing-shaft if this is, as is usual, a route designed to be passable. Such a passage must consequently be protected against rockfalls and against falling objects. It therefore needs a facing. A planned airway must as a rule be protected with walling.

The invention stems from an already known intermediate bunker (DE-OS 30 16 789). In this, the climbing-shaft comes together with the ventilation channel, that is to say the walling of the airway is identical with the facing of the climbing-shaft. The whole is accommodated in the bulk material bunker which is a circular bunker, preferably in the centre of the latter and is realised with an inner cylinder on which a spiral chute is mounted outside. In order to maintain the necessary cross-section, but on the other hand to keep down the loss in volume of the bulk material space which is caused thereby, the climbing and ventilation shaft has a circular shaft cross-section, whose circumference is formed by the facing, which lays down the ventilation cross-section in which the upcast-lead is accommodated.

When the bulk material bunker is emptied, the suction effect on the facing of the climbing and ventilation shaft is inordinately great.

This endangers the fastening of the spiral chute, and also of the facing itself, which can lead to considerable damage. Given the usual cross-sections in pit coal mining, such a bulk material bunker has a quantity of bulk material which makes up approximately 3 to 5 cubic metres per metre of perpendicular iength of bunker. If one proceeds from the basis that in many cases it is a question of bunker heights of approximately 5 metres, on the same floor, as the upper limiting value, then the capacity of such bunkers, at 15 to 30 cubic metres, is substantially too small in relation to the necessary bulk material space of about 100 cubic metres to be related to the conveyor capacity.

This leads to appreciable difficulties in the conveying process, or makes intermediate bunkering underground illusory from the start, how ever desirable it might be in gallery branches in particular, or in crossings of conveying tracks.

The object of the invention is to create a bulk material bunker which is better suited in particular for intermediate bunkering associated with efficient continuous conveyors in local circumstances which allow only a relatively small perpendicular height for the intermediate bunker, and where furthermore the danger caused by the suction effect of the bulk material when the bunker is emptied has to be neutralised.

In accordance with the invention there is provided a bulk material bunker for underground operations, more particularly a perpendicular circular bunker whose bulk material chamber is formed by the walling of a shaft and is changed with the bulk material from above, with the aid of a spiral chute, which reaches as far as a bunker outlet and through which the bulk material arrives in the bulk material chamber, out of which is a climbing and ventilation shaft having its facing hollowed and in which a recess for the climbing and ventilation shaft is fitted on the bunker wall and its facing on a part of its cross-section is formed by the shaft walling, and the recess is in a part of the facing of the climbing-shaft which, together with the facing of the recess and with the shaft walling directed to the latter, forms an airway into which the climbing-shaft is integrated.

In this arrangement the overlap of the venti lation cross-section and the upcast cross-section of the climbing and ventilation shaft, spe cified in the mode of construction, is such that the ventilation function is divided off to form a part of the upcast function. This sepa rated part can hence exhibit a form of cross section which is unusable for direct ascent or descent but can be used by the ventilation system. On the other hand the cross-section of the climbing-shaft can be reduced to the function of ascent/descent, although of course this cross-section too is ventilated. This is achieved by the integration of the climbing shaft cross-section into the ventilation cross section. This arrangement, is shifted on to the side of the bunker and incorporates the bunker walling in the facing.By this means the partial cross-section, as a whole, of the bunker loading chamber which has to meet the demands of the climbing and ventilation shaft, and detracts from the bunker volume, is substantially diminished.

Experience shows that by this means the bunker loading chamber can have a specific magnitude of approximately 20 to 25 cubic metres, with which the requisite bunker volume of 100 cubic metres with the given perpendicular height is attainable without further ado. The invention has the advantage that the suction forces of the bulk material acting upon the facing during withdrawal from the bunker no longer arise in practice, and hence do not need to be taken into account in calculations for the dimensioning of the facing.As has in fact surprisingly emerged, the bulk material flows from the walls of the bulk material chamber in the bunker in the direction of the centre of the bunker, and only then downwards, which causes the suction effect originating from the bunker walls to increase considerably in the centre of the bunker, while at the bunker walls it is practically no longer detectable.

Preferably and particularly when the bulk material bunker is formed as a circular bunker, the cross-section of the recess is bounded on the side of the bulk material chamber by a segment of a circle and the facing of the climbing shaft is of arched form with straight sidepieces which, at a distance from the ends of the segment of the circle are joined to the facing of the recess. With other than squared cross-sections, with the application of steelgirder construction to the partitioning of the climbing and ventilation shaft, a relatively great rigidity of form can be attained. The crosssections resulting from this are also suitable for reaching, from the climbing-shaft, all parts of the ventilation shaft in order to be able to carry out repairs, if the need arises.

Conveniently, the spiral chute with its outer edge following the shaft walling is fitted adjacent to the facing and reaches as far as the inner rim of a funnel forming the bunker outlet. In such an arrangement of the bulk material bunker, the spiral chute is provided which fulfils the function previously described.

The pitch of the spiral chute then corresponds to the actual bunker height, but can also be freely chosen on the basis of technical considerations of conveyor processes in so far as the bunker height permits this.

Advantageously, the inner rim of the bunker outlet funnel forms the upper end of a funnel inlet whose walls represent an extension of the outlet funnel.

With a concept of steel-girder construction for a bunker of this kind it is possible to apply this to various bunker diameters. This is made practical by means of the separately shaped funnel inlet which is necessary for larger bunker diameters, while smaller bunker dia meters can be controlled with the bunker out let.

The climbing and ventilation shaft may be formed as an airlock.

Ventilation blocks may thus be prevented.

The climbing and ventilation shaft may be hollowed out of the wall of the funnel outlet and/or of the outlet funnel.

This is convenient when one has to shift the funnel inclination of the bunker outlet partially into the shaft outflow, which can become necessary when the gallery height is limited, irrespective of the angle of slide of the bulk material.

The invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a bulk material bunker, constructed according to the invention, as an intermediate store between continuous conveyors, shown in longitudinal section, Fig. 2 is a section along the line ll-ll of Fig.

1,and Fig. 3 is a plan view of the bunker of Fig. 1 in the direction of the arrow A.

A perpendicular, cylindrical shaft 1 connects the ridges 2 of a conveying track 3, whose floor is reproduced at 4, with the upward discharge of a continuous conveyor 5. The continuous conveyor 5 is in the form of a belt, whose discharge end pulley is shown in dotted lines at 6. The discharge end pulley works together with a transfer 7, which is provided with a facing 8. The outlet 9 of the transfer 7 is connected with the inlet 10 of a spiral chute 11 which is assembled from individual flights 12, 13 fitted to the walling 14 of the shaft 15. The walling 14 consists of a ferro-concrete cylinder which merges into the gallery walling 16 of the track 3.

On several I-girders 17, 18 cross-arms 19 are laid which take a cover 20 of the shaft and also take the transfer 7 which has been described.

On several posts 21, 22 which are joined together with cruciform fitted struts 23, 24 there is a platform 25 on which the parts of a vibrating trough 26 are fitted. The vibrating trough serves to act upon the unreturned infeed of the continuous conveyor disposed in the conveying track 3, which can likewise be formed as a conveyor belt. The transfer of the vibrating trough 26 is provided with a facing 27. On the platform 25 a traversing platform 28 is accommodated which is safeguarded by a lattice 29 and can be reached from the floor 4 by a ladder 30. The traversing platform 28 allows access to a further ladder 31 which leads into the lower entrance 32 of a climbing and ventilation shaft 33. The cross-section of the climbing and ventilation shaft 33 is recessed out of the loading chamber 34 of the shaft 1 which serves as a bunker.An upper facing 34 safeguards the entrance of the climbing and ventilation shaft against falling objects and the cover 20 closes the bunker on top.

The bunker outlet in general is marked 35 and has a funnel 36 below. Over a vane 37 the outlet funnel 36 is connected with a funnel inlet 37. The upper rim of the funnel inlet 37 is marked 38 and picks up the last spiral flight which is marked 38.

The funnel outlet 35 is divided with the aid of a ridged roof 39 whereby the bulk material in the funnel is split into two streams which are taken in by the vibrating trough 26.

As the plan view of Fig. 3 makes clear, the cross-arms 19 are locked together into a squared frame 40. The arrow 41 reproduces the direction of conveyance of the continuous conveyor accommodated in the track 3. The centre of the bunker is indicated at 42, while the centre of the outlet funnel 35 is shown at 43. The centre of the outlet thus coincides with the centre of the circular bunker and/or its walling 14.

From Fig. 3 it can further be seen that the climbing and ventilation shaft recessed out of the bunker or loading chamber 34 is fitted on the bunker wall, that is to say on the walling 14. This purpose is served by a facing 44 as well as a part of the shaft walling 14 which is marked 45. The facing 44 consists of steel plates which follow the delimitation line of the segment of a circle. The diameter of this circle is relatively great. It corresponds approximately to the diameter of the shaft walling 14. The ends 46, 47 of the facing 44 are immediately adjacent to the shaft walling 14.

The ends 46, 47 of the facing 44 are immediately adjacent to the shaft walling 14.

From Fig. 2 it can be seen that in the recess 48 of the climbing and ventilation shaft a part of the facing, marked 49 as a whole, of the climbing shaft 50 is accommodated. This facing is arched on the outside as shown at 51 and exhibits two sidepieces 52 and 53.

The sidepieces are parallel and are joined on the inside to the facing 44 following the segment of the circle.

Fig. 3 shows that the upper end of the ventilation shaft, which is marked 54, is covered by a protective grille 55 which safeguards the ventilation shaft against falling objects but which allows the passage of air. The climbing shaft is thus incorporated in the ventilation shaft, that is to say in the recess 48. The structure consisting of both parts is divided into flights 56 which are joined to one another with flanges 58. As the illustration of Fig. 2 demonstrates, the facings 54 and 49 are also recesed out of the wall 59 of the funnel, so that a climbing and ventilation way, safeguarded on all sides, is attainable with the ladder 31.

In operation, the material conveyed, coming from the discharge end pulley 6, follows the dotted line 60 of Fig. 1 and thereby passes into the spiral inlet 10. When the bunker is empty, the material follows the spiral chute 12 and via the latter's outlet 38 it reaches the funnel wall. It follows the latter to the funnel outlet and thereby reaches the vibrating conveyor trough 26, by means of which the next conveyor is charged. If the latter's conveying capacity is too small to accept the total quantity of material fed in, the vibration amplitude of the vibrating conveyor trough can be adjusted through the drive 61, so that the quantity drawn out of the loading chamber 34 of the bunker is reduced. Conveyance through the vibrating trough 26 can also be interrupted for the same purpose. In this case the material follows the vibrating chute 12 until the funnel 35 and its headpiece are filled. Then the material conveyed flows over the inner edge 62 of the spiral chute into the bunker chamber located in the eye of the spiral chute which is thereby filled. The facing 44 then secures the climbing and ventilation shaft visa-vis the bunker chamber.

As soon as the loading of the flow conveyor device connected on the output side diminishes, the quantity conveyed out of the bunker loading chamber 34 can be increased with the aid of the vibrating conveyor trough 26 until the chamber is emptied. Subsequently the storage function can automatically be reestablished as the need arises.

Claims

1. A bulk material bunker for underground operations, more particularly a perpendicular circular bunker, whose bulk material chamber is formed by the walling of a shaft and is charged with the bulk material from above, with the aid of a spiral chute, which reaches as far as a bunker outlet and through which the bulk material arrives in the bulk material chamber, out of which is a climbing and ventilation shaft with hollow facing, in which a recess for the climbing and ventilation shaft is fitted on the bunker wall and its facing on a part of its cross-section is formed by the shaft walling, and the recess is in a part of the facing of the climbing-shaft is fitted which, together with the facing of the recess and with the shaft walling directed to the latter, forms an airway into which the climbingshaft is integrated.

2. A bulk material bunker according to Claim 1, wherein the cross-section of the recess is bounded on the side of the bulk material chamber by a segment of a circle and the facing of the climbing-shaft is of arched form with straight sidepieces which, at a distance from the ends of the segment of the circle are joined to the facing of the recess.

3. A bulk material bunker according to either of Claims 1 and 2, wherein the spiral chute with its outer edge following the shaft walling is fitted adjacent to the facing and reaches as far as the inner rim of a funnel forming the bunker outlet.

4. A bulk material bunker according to any one of Claims 1 to 3, wherein the inner rim of the bunker outlet funnel forms the upper end of a funnel inlet whose walls represent an extension of the outlet funnel.

5. A bulk material bunker according to any one of Claims 1 to 4, wherein the climbing and ventilation shaft is hollowed out of the wall of the funnel outlet and/or of the outlet funnel.

6. A bulk material bunker according to any one of Claims 1 to 4, wherein the climbing and ventilation shaft is formed as an airlock.

7. A bulk material bunker for underground operations substantially as hereinbefore described with reference to and as shown in the accompanying drawings.