Patent Application
20110042033
This invention relates to apparatus for laying elongate elements.
In one aspect there is provided apparatus for laying an elongate member, the apparatus having means for continuous forming the elongate member, and means for laying the elongate member as it is formed and as the apparatus travels on a ground surface.
The apparatus may include means for forming molten material and means for forming the elongate member therefrom. The means for forming may form the elongate member by continuous forming. The continuous forming may be effected by continuous casting. The apparatus may have means for storing in flowable the material or at least one component for forming the material in flowable form, such as in granular or particulate form. Means may be provided for delivering the material or said component, in flowable form, to the means for forming molten material, and for delivery thence to the molten material to mould means for casting the elongate member therefrom.
The material from which the elongate member is formed may be metal, and the apparatus for forming may be in the form of a furnace for forming the material as metal, such as by smelting. The apparatus for forming may be a plasma arc furnace.
The elongate member may for example be a pipe, cable or the like, and the apparatus may have excavating means for forming a trench into which the elongate member is in use of the apparatus laid. The elongate member may be a rail, and the apparatus may be arranged to lay the rail forwardly of the apparatus, so that the apparatus may travel on the rail during laying.
In another aspect, the invention provides a method of laying an elongate member, wherein the elongate member is continuously formed on a transport vehicle, and laid by the transport vehicle as the transport vehicle travels.
The method may include forming material in molten form and forming the elongate member by casting of the molten material. The elongate member may be continuously cast. The material, or at least one component for forming the material, may be stored in particulate or other flowable solids form on the transport vehicle, prior to causing the material to be formed in the molten state. The molten material may be delivered to a casting head to form the elongate member therefrom by a continuos casting process.
The molten material may be metal, which may be formed by smelting, such as in a plasma arc furnace.
The elongate member may for example be a pipe, cable, rail or the like.
The method may include excavating, by an excavator on the transport vehicle, to form a trench into which the elongate member is laid. Where the elongate member is a rail, the rail may be laid forwardly of the vehicle, and the vehicle may travel on rail so laid.
The invention is further described by way example only with reference to the accompanying drawings in which:
The apparatus 300 shown in
Apparatus 300 has a support frame 316 to which are mounted pairs of side by side tractor drives 318 for moving the apparatus over the ground surface 308.
At a forward location, a control cabin 302 is provided from which the operation of the apparatus is controlled by one or more operators. Also at the forward end, the apparatus has a rotary digger 320 for excavating earth to form the trench 314.
At the rear, apparatus 300 has a plasma arc furnace 340 for producing molten metal from materials in hoppers 322, 324, 326 at the forward end of the apparatus. The molten metal is fed from the furnace 340 to a casting head 342 at the rear of the apparatus and from which the pipe 306 is extruded into the trench 314.
As shown in
The furnace 340 is formed in the manner described in our Australian Patent Application No. 2005904332 filed 11 Aug. 2005 and our Australian Patent Application entitled “Improved Smelting Furnace”, filed the same day as the present application. The contents of these specifications are hereby incorporated into the present specification to form part thereof.
The following is a brief description of the furnace 340. For a fuller understanding of its operation, reference should be made to the mentioned patent specifications.
The furnace 340 has a double walled metal vessel 420 having a highly polished dome-like interior upper surface 422. Cooling liquid, such as liquid sodium, is circulated in the space between the two walls of vessel 420 for cooling the vessel. Material in duct 405 is delivered centrally at the top of the vessel 420 into an internal chamber 424 thereof via an electrode forming head 412, more particularly through a central upright opening 425 in the head 412. A hollow cylindrical electrode 426 of carbonaceous material is formed by downwards extrusion from the head 412 between parallel concentric annular walls 428 which extend downwardly from the head 412. Particulate carbonaceous material and liquid pitch for forming the electrode 426 are fed to the head 412 via ducts 430, 432.
A lower electrode 440 is formed in the base of the vessel 420 in internal chamber 424. As material from the kiln 390 is passed down through the head 412, it falls down the hollow interior of the electrode 426 to accumulate on the floor of the interior of the furnace. Inert gas, such as argon, is passed into the chamber 424 via a central downwardly extending pipe 427 within the electrode 426. Means (not shown) is provided for applying DC electric potential across the electrodes 426, 440, with electrode 426 as a cathode and electrode 440 as an anode. By this application of electric potential, the introduced gas in the furnace from pipe 427 is ionised to form a plasma and the material introduced into the vessel 420 is heated to a high temperature, aided by the internal reflective surface 422 of the vessel 420. As a result, the material in the furnace is smelted. Resultant liquid slag 442 is removed from vessel 420 via an outlet 444, and resultant molten metal 446 accumulating at the bottom of the interior of the vessel 420 is removed via an outlet 448.
Off gas formed during smelting in furnace 340 is removed from the furnace via an upper pipeline 450 and fed back into the cylindrical element 392 of kiln 390, at the lower end thereof, to pass upwardly through the element 392 to exit the kiln via an upper outlet duct 452. A fan 460 may be provided to facilitate this passage of the off gas through the kiln 390.
The hot off gas passed through the kiln 390 serves to preheat the material passing therethough to the furnace 340. The off gas passes from the kiln 390 at the upper end thereof via a duct 452.
The casting head 342 is shown in more detail in
The casting head 342 has a central internal mould element 395 which is of cylindrical form, being positioned in the mould 370 towards the inlet end thereof. It is positioned with its periphery spaced inwardly from the inner periphery of the mould 370 by a distance equal to the intended wall thickness of the pipe 306.
Molten metal 446 for furnace 340 passes into mould 370 from furnace outlet 448, passing between the element 395 and the inner periphery of the mould 370. Accordingly, the molten metal is conformed to an annular cross-sectional shape which, by action of the coolant circulated through the mould 370 is maintained as the metal passes through mould 370. The so formed tubular structure of the metal introduced into the mould 370 is maintained as it passes through the mould 370. At exit from the mould 370, the metal is still quite hot and can be bent. The so formed hot pipe 306 passes between sets of rollers 396 to bend the pipe 306 from the somewhat vertical orientation adopted as the pipe emerges from the mould 370 to a substantially horizontal state. The pipe is progressively deposited at the bottom of the trench 314, as the apparatus 300 moves along ground surface 308.
The preheating of material passing through kiln 390, by action of the hot off gas through the kiln, facilitates operation of the furnace 340. The off gas, after passing into the duct 452 at the upper end of the kiln passes along duct 452 and, as shown in
After leaving the hopper 326, duct 452 conveys off gas to processing apparatus carried by the frame 316 of the apparatus 300 and which is illustrated diagrammatically only in
Material separated from the fine metal dust, carbon and ash in the precipitator 142 is passed to a vortex scrubber 505, which also receives micronised limestone 511. From the vortex scrubber 505, there emerges clean air 507 and separated limestone slurry 509. Slurry 509 has entrapped materials such as sulphur and superfine gases or dust. The slurry may be retained in a suitable receptacle on the apparatus 300 and periodically removed for separate disposal.
Power for the apparatus 300, for driving the tractor drives 318 and otherwise for operating the apparatus 300, may be derived from one or more motor driven generators, such as diesel generators, mounted on the apparatus.
The materials from which the pipe 306 is formed may be varied, depending on requirements. In a typical application, the material may comprise metal in the form of powder or of granular or similar form, stored in hopper 322, a suitable flux material in particulate form such as limestone; stored in hopper 324, and a suitable reductant such as granular coal or coke, stored in hoppers 326. By this, the resultant smelted material for forming the pipe 306 is iron or a suitable alloy containing iron.
In a modification (not shown) there may be more than one furnace 340, with storage and transport arrangements made for supply of differing mixes of constituents thereto. For example, the apparatus may be arranged to feed the casting head 342 with metals of different compositions, derived from separate furnaces 340, such that metals of different compositions are extruded one around the other. By this, an inner portion of the pipe 306 may have one metallic composition and the outer part thereof another metallic composition.
The invention may be adapted to lay elongate elements other than pipes. For example,
In this case, the cast metal to form the rails and the sleepers is formed at the forward end of the apparatus 408, and the apparatus, instead of having tractor drives 318, has wheels 476 which a driven by a suitable motor to enable the apparatus 400 to run on the rail line as it is formed.
The metal section 462 which is extruded by head 406 is cut into sleeper length sections 462 by a suitable cutting means such as a metal saw (not shown) and then transported (by means not shown) forwardly on the apparatus to the front of the apparatus where the lengths are grasped by a swingable mechanical arm and successively laid transversely on the ground at the front the apparatus 408 to form the sleepers 474, and such that the rails 472 are laid on the sleepers as the apparatus moves along the already laid rail line.
The sleepers may be extruded in a suitable cross-section such as the section shown in
Means (not shown) may be provided for securing the rail to the sleepers as the apparatus 400 progresses. Thus, welding heads may be provided for this purpose so as to weld the sleepers to the rails, or apparatus may be provided for drilling the sleepers, possibly before laying, and for subsequently securing the sleepers to the rails by use of conventional rail fasteners.
The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
The described arrangements have been advanced merely by way of explanation and many modifications may be made thereto without departing from the spirit of the scope of the invention which includes every novel feature herein disclosed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005906708 | Nov 2005 | AU | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/AU06/01819 | 11/30/2006 | WO | 00 | 9/21/2010 |
