WO2006049550A1

WO2006049550A1 - Destruction facility

Info

Publication number: WO2006049550A1
Application number: PCT/SE2005/001569
Authority: WO
Inventors: Johnny Ohlson
Original assignee: Olcon Engr AB
Current assignee: Olcon Engr AB
Priority date: 2004-11-04
Filing date: 2005-10-21
Publication date: 2006-05-11
Anticipated expiration: 2007-05-04
Also published as: SE0402676L; SE526958C2; SE0402676D0

Abstract

The present invention relates to a method and an arrangement, in conjunction with an actively initiated thermal destruction, involving detonations, of bodies filled with explosive substances, for restricting the effect on the environment of detonation waves produced by the detonations of the bodies and of shrapnel formed from the outer casings of the aforementioned bodies accompanying the detonation waves. In accordance with the invention, movements of the detonation waves and the aforementioned shrapnel are attenuated in that the space inside which the detonations are carried out is surrounded by a multi-shell labyrinthine outlet comprising groups of shrapnel-absorbing means (13,16) which force the detonation waves and the shrapnel, to the extent that they are not fully arrested by the aforementioned means (13,16), to change direction at least to a certain extent and, in conjunction with their continued propagation, to move along gaps or channels (14,17) arranged between the aforementioned means.

Description

Destruction facility

TECHNICAL FIELD The present invention relates to a method, in conjunction with an actively initiated thermal destruction, involving detonations, of bodies filled with explosive substances, for restricting the effect on the environment of detonation waves produced by the detonations of the bodies and of shrapnel formed from the outer casings of the aforementioned bodies accompanying the detonation waves.

The invention also relates to an arrangement, in accordance with the method, in conjunction with the destruction of bodies filled with explosives inside a chamber intended for the purpose provided with an essentially gas-tight outer shell by means of an actively initiated thermal destruction, involving detonation, for restricting the effect on the inside of the outer shell of the chamber of detonation waves produced in conjunction with detonations of the bodies and shrapnel formed from the outer casings of the aforementioned bodies accompanying the detonation waves.

The invention thus relates in its most generally applicable form to a method, in conjunction with the thermal destruction of bodies filled with explosives involving the heating of explosives 'Contained therein thereby causing them to detonate or to be incinerated inside a limited space, for restricting the effect on the environment of detonation waves produced by the detonation of the bodies and of shrapnel formed from the outer casings of the aforementioned bodies accompanying the detonation waves. The method in accordance with the invention thus has its greatest value in facilities of a kind in which shrapnel-forming charges are detonated continuously inside a restricted _ p —

space. In its fully developed form, the invention consists of a destruction facility for the thermal destruction of bulk materials with an associated risk of detonation, such as all types of ammunition, land mines and equivalent types of explosive-filled bodies.

PRESENTATION OF THE PROBLEM AND BACKGROUND ART

Large quantities of such materials are kept in storage at many locations in the form of ammunition that is surplus to requirements or obsolete, of which the individual shells, service charges, etc., and/or the propellant charge, do not contain quantities of explosive sufficiently large for their dismantling and recovery of the explosive for reuse to be worthwhile, or present a risk in conjunction with dismantling, which is the case with corroded ammunition. Any metal components contained therein only constitute scrap metal in any event, although they cannot be utilized as scrap until it is known with absolute certainty that they no longer contain any undetonated explosive.

For the purpose of the thermal destruction of such material, it is introduced in batches with limited explosive power into a stationary or rotating furnace or other destruction chamber, inside which the material is heated until the explosive contained therein is incinerated, which will take place to a certain extent through detonation, at the same time as any metal components present in the products in question are transformed into harmless scrap. In order for the destruction of such bulk materials with an associated risk of detonation to be capable of being performed in a more or less continuous process, which is necessary for economic reasons, it is essential for the material to be capable of being supplied in batches to the destruction chamber intended for the purpose under acceptable conditions of safety, which chamber must also be capable of being emptied of scrap subsequent to its destruction without excessive disruption of the continuity of the process. A continuous destruction process of this kind will nevertheless produce exceptionally severe wear on the destruction chamber or furnace inside which it is performed. It is certainly possible, by continuously retaining a proportion of the scrap material bed that is successively being formed inside the destruction chamber, to achieve a certain degree of protection for that part of the interior of the chamber in which the scrap material bed is present, although remaining parts of the interior of the chamber will be exposed continuously to both detonations and the detonation waves associated therewith and shrapnel distributed as a result thereof, at the same time as the continuous exposure of the chamber in its entirety to high temperatures will soften the steel material from which the wall of the chamber is manufactured to a greater or lesser degree.

Large quantities of combustion gases that are harmful to the environment will, of course, be formed in the course of the continuous destruction of explosive- filled bodies of the kind proposed here. In order to permit these to be dealt with in a satisfactory fashion, it is accordingly necessary for the destruction chamber that is utilized for destruction to be provided with an impervious outer casing. One possible means of extending the service life of the outer casing of the destruction chamber can thus involve the arrangement, in the interior of the chamber, of a replaceable inner protective shell intended for the purpose, so to speak, of absorbing most of the detonation waves and shrapnel produced in conjunction with the detonations.

PURPOSE OF THE INVENTION AND ITS DISTINCTIVE FEATURES

The present invention could now be defined essentially as a means for providing a destruction chamber of this kind with a specially executed multi-walled inner protective shell, which not only exhibits the ability - A - to absorb the shrapnel and detonation waves produced in conjunction with the destruction, but also contributes actively to restricting the force of the detonation waves produced in conjunction with the destruction.

The invention could thus be defined firstly as a means, in conjunction with the thermal destruction of explosive-filled bodies, for restricting the effect on the environment of detonation waves produced in conjunction with the detonations of the bodies and of shrapnel formed from the outer casings of the aforementioned bodies accompanying the aforementioned detonation waves. The movements of the detonation waves and the shrapnel, at least in the directions of propagation that can be expected to be of the greatest detriment to the environment, are deflected in this way towards detonation wave-deflecting and shrapnel- absorbing means arranged transversely to the aforementioned directions of propagation, which means force the detonation waves and the shrapnel, to the extent that they are not fully arrested by the aforementioned means, to change direction at least to a certain extent and, in conjunction with their continued propagation, to move along gaps or channels arranged between the aforementioned means, within which the velocity of the detonation waves is further attenuated at the same time as any accompanying shrapnel is caught inside the channels. It is also possible to arrange a second set of detonation wave-deflecting and shrapnel- trapping means in turn transversely to the actual openings to these gaps or channels, although at a certain distance from the aforementioned openings, which means in turn exhibit between them gaps or channels of a corresponding type. Having regard for the fact that the aforementioned second set of detonation wave-deflecting and shrapnel-trapping means lies transversely to the aforementioned first set of gaps or channels, the aforementioned second set of means will arrest the continued movement of the detonation waves and the shrapnel in the direction in which they were previously guided by the previously mentioned gaps. The aforementioned second set of detonation wave-deflecting and shrapnel-trapping means thus, in turn, imposes a further change in direction on the detonation waves and any shrapnel by which they are still accompanied. In this way, these different sets of detonation wave- deflecting and shrapnel-trapping means, which can consist of two or more sets of such means arranged concentrically outside the active interior of the detonation chamber, together constitute a form of labyrinthine outlet. In their most practical design, these means consist of robust metal rings arranged concentrically around the active interior of the detonation chamber and concentrically outside one another at a certain distance from one another, between which rings are provided gaps of the kind described above, which gaps lie axially offset between the different sets of means.

The underlying principle is thus, quite simply, that the detonation waves and the shrapnel are caused to decelerate in a first stage as they encounter a first set of means arranged transversely to the direction of propagation of the detonation waves, between which means there is arranged a first set of gaps into which the detonation waves are forced in order subsequently to be caused to decelerate in the original direction of propagation of the detonation waves beyond the aforementioned first set of means outside the outlets for the first set of gaps between them by a second set of detonation wave-deflecting means that are arranged transversely to the aforementioned outlet. There is thus present between the first and second sets of the aforementioned means an in principle tubular gap which links together the gaps between the different means in the first and second set of detonation wave-deflecting means. The use of two sets of such sets of means arranged outside one another thus provides at least two surfaces arranged transversely to the direction of propagation of the detonation wave and two changes in direction with compressions into narrow gaps associated therewith. This type of labyrinthine outlet on the whole affords highly effective deceleration of both detonation waves and shrapnel. It will also be clearly appreciated from the following that the means utilized for this purpose can be made very robust and, in addition, easy to replace in the event of any damage.

The underlying principle referred to above that is applied in a destruction chamber for the thermal destruction of explosive-filled bodies results in an arrangement or a chamber consisting of an essentially gas-tight outer shell, which encloses that part of the chamber in which the destruction of the explosive- filled bodies is undertaken, and of an easily replaceable inner double shell in the form of groups of robust metal rings arranged concentrically within one another at a certain distance from one another and in turn enclosing this inner part of the chamber arranged inside the outer wall of the chamber, which rings exhibit within each group a gap between the rings in the group, at the same time as a concentric annular, or rather tubular, gap is maintained between the groups, and in conjunction with which the gaps between the rings in both groups are so arranged that the gaps that are formed in an axial sense by the clearance between the inner rings in the direct radial sense are covered by the outer rings, at the same time as a free tubular space is present between the outside of the outer rings and the inside of the chamber. This fundamental design gives a product with an easily replaceable double- walled inner protective shell which functions as a labyrinthine outlet and as such is capable of withstanding very high internal pressures and large shrapnel loadings and for this reason can be used with advantage for the purpose proposed here. As already indicated, the principle can also be utilized for multi-shelled labyrinthine outlets with three or more shells arranged successively and concentrically outside one another.

In accordance with further aspects of an arrangement in accordance with the invention, it is true that:

- every ring within the aforementioned group of inner rings exhibits studs included in the respective rings, which studs are oriented on the one hand towards neighbouring rings within the group and in so doing will adapt to the gap between the rings within the group, and on the other hand outwards towards the surrounding group of outer rings and in so doing will hold a tubular gap open between the groups of rings.

- every ring in the aforementioned group of outer rings consists of a plurality of interconnected ring parts, in which every joint between the ring parts is arranged directly opposite a guide cam or baffle arranged in the outer shell of the chamber and extending into the chamber, which cam or baffle holds the outer rings at a certain distance from the inside of the chamber wall where it forms an annular space divided up by the baffles.

- every outer ring consists of four ring parts engaged in one another and with one another with a certain overlap, where each ring part also exhibits a locking edge which engages over the far edge of the respective baffle, relative to the position of the ring part, by which the ring part is terminated in that direction.

- it comprises more than two groups of rings arranged concentrically outside one another at a certain distance from one another, of which the gaps that are arranged between the rings in each group and between the groups together form a labyrinthine outlet for pressure waves and accompanying shrapnel. DESCRIPTION OF THE DRAWINGS

The invention is defined in the following Patent Claims, and it is now described in rather more detail in conjunction with the accompanying Figures:

In the Figures,

Fig. 1 shows a sectioned oblique projection of a destruction chamber with certain accessories, Fig. 2 shows a sectioned side view of the actual destruction chamber in accordance with Fig. 1 on a larger scale,

Fig. 3 shows the cross-section A-A in Fig. 2,

Fig. 4 shows on a larger scale a detailed view of the joints between the various ring segments of the outer protective rings,

Fig. 5 shows the same detail as in Fig. 4 viewed from the side, while,

Figs. 6 and 7 show the details contained in Figs. 4 and 5 in an oblique projection,

Fig. 8 shows the destruction chamber in accordance with

Fig. 1 lowered and rotated for the purpose of emptying same.

DETAILED DESCRIPTION OF THE EMBODIMENT

To the extent that the same details can be seen in several of the Figures, these have been given identical reference designations.

The destruction arrangement illustrated in Fig. 1 comprises a destruction chamber 1, the individual features of which are discussed in more detail primarily in conjunction with Fig. 2. The destruction chamber 1 is enclosed in turn by a gas-tight outer shell 2 and, immediately inside the latter, by thermal insulation and an extra safety barrier 3. The interior of the destruction chamber 2 exhibits an upward transition into a charging neck 5, via which the material for destruction is supplied to the interior of the chamber 1. The material for destruction is introduced into the neck 5 via a charging lock 6, of which the many component parts included in Fig. 1 have nothing to do with the invention and are accordingly for the most part not described here in any greater detail. Nevertheless, it is relevant to state that the charging lock 6 is provided with special hatches that are capable of being opened and closed to provide the locking function necessary for safety reasons. The material for destruction is supplied from the charge lock β to the neck 5 via an opening 7 in the outer wall of the neck 5. The opening 7 can in turn be blocked by a hatch 8 capable of being opened inwards into the neck, which hatch is illustrated in the open position in the Figure. In the event of a detonation inside the interior of the chamber 2, the hatch 8 will thus be forced by the pressure waves against the edges of the rim on the opening of the hatch 7. In view of the relative length of the neck 5, it is the space inside the neck that absorbs the pressure waves and any accompanying shrapnel distributed in the longitudinal direction of the neck. The neck 5 exhibits an opening hatch 9 at the top.

The destruction chamber 1 itself is provided, as can be appreciated from Fig. 2 and Fig. 3, with a double outer shell 10,11 and a very robust inner base plate 12. The chamber is additionally lined internally with the double-walled labyrinthine lining that is characteristic of the invention and consists of a first group of robust internal metal rings 13 stacked axially above one another and arranged horizontally, which rings exhibit between them horizontal gaps 14 produced by the fact that the individual rings 13 exhibit spacer studs 15 facing towards the next circle of rings in at least one direction.

Arranged concentrically outside this first group of rings 13, and at a certain distance from these, is a second group of outer rings 16, and these, too, exhibit gaps 17 arranged between them between the rings in the group. This second group of gaps 17 is displaced to such an extent in the vertical sense, however, that the outer rings 16 lie directly opposite the gaps 14 between the inner rings 13. In view of the fact that, as has already been pointed out, a distance is present between the outer rings and the inner rings, an annular, or rather tubular, gap is formed there, which may be essentially regarded as being equivalent to the wall of a tube where the tube wall is thus the actual gap. This tubular gap is identified in the figures with the reference designation 18.

When utilizing the arrangement in accordance with the invention, material for destruction with an associated risk of detonation is introduced into it via the lock arrangement 6 and the hatch 7 into the neck 5, through which the material drops down into the central interior part of the destruction chamber 1, where it is heated to the point of detonation and incineration. Hot scrap from previous destructions that is retained inside the chamber 1 can be utilized in this way, at least to a certain extent, for the purpose of heating the freshly added material for destruction. Previously produced scrap that is retained in this way also affords a certain level of protection for parts of the interior of the chamber 1.

Detonation of the freshly added material with an associated risk of detonation results in the formation of detonation waves which are propagated radially from the centre of the point of detonation, and scrap produced from the non-explosive parts of the material accompanies the detonation wave, and the first obstacle encountered by the detonation waves and the shrapnel is the inside of the inner rings 13 of the double protective inner lining, which cause the detonation wave to decelerate and force it into the gaps 14 between the various rings 13. Those parts of the wave that directly strike the inside of the rings 13 in this case are forced to change direction and, together with other parts of the detonation wave, are forced into the gaps 14, where, outside their openings, they then encounter the outer group of rings 16 arranged directly opposite their respective gaps, with a further deceleration and a new compression into the gaps 17 as a consequence. Present outside the gaps 17 is a further free space 19, which is ultimately utilized to deprive the detonation waves of their kinetic energy once they have been radically subdued by the effect of the gaps 14, 18 and 17. The pieces of shrapnel that are not arrested directly by the respective rings 13 and 16 will be trapped for the most part in the respective gaps 14, 18 and 17, and any pieces of shrapnel that manage to pass through all the gaps will possess such low residual kinetic energy that they will not actually present a problem when they reach the space 19.

In order to align the outer rings 16 and retain them in position inside the chamber 1 so that the free space 19 has the necessary volume, a number of vertical guide baffles 20-23, also referred to below as guide combs, are arranged against the inside of the chamber, as illustrated mainly in Fig. 3. The outer rings 16 are aligned against these guide baffles with special locking edges, such as guide heels 24,25, which engage around either side of the guide baffles 20-23. The inner rings 13 are in turn provided with radial studs 26, which make contact with the inside of the outer rings 16 and thus automatically adapt to the width of the tubular gap 18.

In the example illustrated in the Figures, the inner rings 13 are executed as a unit with their axial studs 15 and their radial studs 26. Each of the outer rings 16, which are significantly larger units, is divided up into four ring parts, however, in the form of segments 27-30, which are hooked in engagement with one another in pairs at the level of the guide baffles 20-23. The method by which these hooked engagements are effected can be appreciated from Figs. 4-7. The various ring segments 27-30 are thus hooked to one another by means of overlapping hook joints, in which one segment exhibits a broad locking groove 31, into which a locking heel 32 on the other segment engages when the segments are assembled into a ring. Every ring segment also exhibits a guide heel 24 or 25, which, with the complete ring in place, makes contact with the far side of the respective guide baffle 20-23. This means that a radial internal load, for example from a pressure wave from a detonation which acts upon the ring segment from its centre, will be absorbed by the guide baffle. Furthermore, each ring segment is executed with a thickened area 33 at its respective outer ends, i.e. at the point where it exhibits its guide groove 31 and its locking heel 32 respectively. When assembled one on top of the other, these thickened areas 33 give rise to the gaps 17 between the outer rings 16.

Illustrated finally in Fig. 8 is the destruction arrangement at the time of emptying of the destruction chamber 1, in conjunction with which the destruction chamber 1 in accordance with Fig. 1 is first lowered to a certain extent before being rotated subsequently to its emptying position.

With regard to Fig. 1, it can also be pointed out that the actual furnace or destruction chamber can be turned upside down for emptying of the recovered scrap contained therein. However, the suspension of the furnace and the frame for that purpose, as well as the associated rotating device, have not been included in the Figures in the interests of clarity, like the heating devices necessary for heating the furnace.

ALTERNATIVE EMBODIMENTS The invention is not restricted to the embodiment proposed here, but may be varied in a number of ways within the scope of the Patent Claims.

Claims

Case 1021 - 14 -Patent Claims

1. A method, in conjunction with an actively initiated thermal destruction, involving detonations, of bodies filled with explosive substances, for restricting the effect on the environment of detonation waves produced by the detonations of the bodies and of shrapnel formed from the outer casings of the aforementioned bodies accompanying the detonation waves, characterized in that movements of the detonation waves and the aforementioned shrapnel, at least in the directions of propagation that can be expected to be of particular detriment to the environment, are deflected against detonation wave- deflecting and shrapnel-absorbing means (13,16) arranged transversely to the aforementioned directions of propagation, which means force the detonation waves and the shrapnel, to the extent that they are not fully arrested by the aforementioned means (13,16), to change direction at least to a certain extent and, in conjunction with their continued propagation, to move along gaps or channels (14,17) arranged between the aforementioned means .

2. A method in accordance with Claim 1, characterized in that the detonation waves and the shrapnel, in those directions in which it is particularly wished to afford protection, are forced to change direction by at least two groups of detonation wave-deflecting and shrapnel- absorbing means (13,16) arranged after one another in the aforementioned directions.

3. An arrangement, in accordance with the method in accordance with Claims 1-2, in conjunction with the destruction of bodies filled with explosives inside a chamber (1) intended for the purpose and provided with an essentially gas-tight outer shell (2), by means of an actively initiated thermal destruction, involving detonations, for restricting the effect on the inside of the outer shell (10,11) of the chamber of detonation waves produced in conjunction with detonations of the bodies and shrapnel formed from the outer casings of the aforementioned bodies accompanying the detonation waves, characterized in that at least that part of the interior of the chamber inside which destruction of the aforementioned bodies takes place is surrounded by an easily replaceable inner double shell (13,16) in the form of groups of robust metal rings (13,16) arranged concentrically within one another at a certain distance from one another in turn enclosing this inner part of the chamber arranged inside the outer wall (10,11) of the chamber, which rings exhibit within each group a gap (14,17) between the rings in the group, at the same time as a concentric annular gap

(18) is maintained between the groups, and in conjunction with which the gaps (14,17) between the rings (13,16) in both groups are so arranged that the gaps (14,17) that are formed in an axial sense by the clearance between the inner rings (13) in a directly radial sense are covered by the outer rings (16) .

4. An arrangement in accordance with Claim 3, characterized in that every ring (13) within the aforementioned group of inner rings exhibits studs (15,26) included in the respective rings, which studs are oriented on the one hand towards neighbouring rings within the group and in so doing will adapt to the gap (14) between the rings within the group, and on the other hand outwards (18) towards the surrounding group of outer rings (16) and in so doing will hold a tubular gap (18) open between the groups of rings.

5. An arrangement in accordance with Claims 3-4, characterized in that every ring in the aforementioned group of outer rings (16) consists of a plurality of interconnected ring parts (27-30), in which every joint between the ring parts is arranged directly opposite a guide cam or baffle (20-23) arranged in the outer shell of the chamber and extending into the chamber, which cam or baffle holds the outer rings (16) at a certain distance from the inside of the chamber wall (10,11) where it forms an annular space (19) divided up by the baffles.

6. An arrangement in accordance with Claim 5, characterized in that every outer ring (16) consists of four ring parts (27-30) engaged in one another and with one another and with a certain overlap, where each ring part also exhibits a locking edge (24,25) which engages over the far edge of the respective baffle (21-23) , relative to the position of the ring part, by which the ring part is terminated in that direction.

7. An arrangement in accordance with Claims 3-6, characterized in that it comprises more than two groups of rings arranged concentrically outside one another at a certain distance from one another, of which the gaps that are arranged between the rings in each group and between the groups together form a labyrinthine outlet for pressure waves and accompanying shrapnel.