Improvements in or relating to blast furnace apparatus

Abstract

 The invention provides blast furnace apparatus wherein granular coal is arranged to be injected, by means of a lance (4), into the furnace through a blast 'pipe (3) thereof, including a check valve assembly in the wall of the blast pipe through which the lance is passed, said check valve assembly including a chamber (8) disposed above and radially outwardly from a bore (7) passing therethrough and adapted to receive the lance; a collar member (10) adapted to be seated at least partially around the bore and opening on one side into the chamber, the collar having an inclined surface generally directed away from the outlet mouth of the blast pipe; and a ball (9) adapted to be held in the chamber by the lance when passed through the valve into the blast pipe and adapted to run down the inclined surface of the collar into the bore upon withdrawal of the lance from the bore so as to close the bore and seal the valve assembly.

Description

[0001] This invention relates to blast furnace apparatus for the production of iron.

[0002] It has been proposed that, in addition to the carbonaceous fuel added in the blast furnace charge, additional fuel should be added to the blast furnace during processing of the charge via the blast pipe and tuyere system.

[0003] It has been further proposed that this should be done by means of a lance projecting through the blast pipe and arranged to inject into the gas passing through the tuyere a fuel of one kind or another.

[0004] With such an arrangement it is necessary that there should be a facility for removing a lance from the blast pipe in the event of blockage or other malfunction. To enable this to happen it is necessary that the lance pass through a port to the blast pipe so arranged that upon removal of the lance this entrance is sealed against the back pressure from the gas within the blast pipe. Whilst check valves to accomplish this have been proposed with regard to liquid or sem-liquid fuel or pulverised fine grain fuel entrained in a gas or a liquid, problems arise in the design of an appropriate check valve in connection with relatively coarse grain material such as granular coal (up to approximately 3 mm in diameter for example).

[0005] It is an object of the present invention to overcome or at least substantially reduce this problem.

[0006] According to the invention there is provided a blast furnace apparatus wherein granular coal is arranged to be injected by means of a lance through a blast pipe thereof including a check valve assembly in the wall of the blast pipe through which the lance is passed, said check valve assembly including a chamber disposed above and radially outwardly from a bore passing therethrough and adapted to receive the lance; a partial collar adapted to be seated around the bore and opening on one side into the chamber, the collar having a face inclined away from the outlet mouth of the blast pipe; and a ball adapted to be held in the chamber by the lance when passed through the valve into the blast pipe and adapted to run down the inclined face of the collar into the bore upon withdrawal of the lance from the bore so as to close the bore and seal the valve assembly.

[0007] The ball is preferably of stainless steel.

[0008] In order that the invention may be more readily understood one embodiment thereof will now be described by way of example with reference to the accompanying drawing which is a sectional side elevation of a check valve for use in apparatus according to the invention.

[0009] Referring to the drawings it will be seen that the check valve assembly 1 is mounted on a cylinder 2 welded to a wall 3 of a blast pipe of a blast furnace (not shown). The b;ast pipe is provided in known manner with a curved gas inlet such that the cylindrical attachment of the check valve can be attached generally tangentially to the curved inlet with the lance 4 extending directly towards the tuyere outlet.

[0010] The valve assembly 1 includes a major body portion 5 attached to the attachment cylinder 2 at one end and a handle carrying sub-assembly 6 at the other end. A bore 7 is provided through the main assembly block 5 and sub-assembly 6, to enable the hollow granular coal injecting lance 4 to be passed therethrough into the blast pipe for fuel injection purposes.

[0011] The main body portion 5 of the check valve 1 includes a chamber 8 disposed above the bore and injection lance, within which a steel ball 9 is held by the lance.

[0012] Mounted within the main body portion 5 below the chamber 8 is a partial collar member 10 having a vertical cross section somewhat in the form of an isosceles triangle. Thus it will be seen that the collar member 10 has a face 11 towards the tuyere generally at right angles to the axis of the lance 4, whilst the face 12 directed away from the tuyere is inclined at an angle of approximately 45° to the axis of the lance 4 . Should it be necessary to remove the lance 4 for reasons of blockage or excess wear or other reasons, this can readily be withdrawn from the blast pipe through the check valve assembly 1. As soon as the lance is free from the stainless steel ball 9 this immediately runs down the inclined face 12 of the partial collar 10 and connects for sealing purposes with edges of an annular recess 13 within the main body portion 5.

[0013] By means of the invention as particularly described, there is provided an arrangement enabling rapid and effective sealing of a lance entrance to a blast pipe despite the large diameter bore . required for a lance used for granular coal injection into the tuyere of a blast furnace.

Claims

1. Blast furnace apparatus wherein granular coal is arranged to be injected, by means of a lance, into the furnace through a blast pipe thereof, including a check valve assembly in the wall of the blast pipe through which the lance is passed, said check valve assembly including a chamber disposed above and radially outwardly from a bore passing therethrough and adapted to receive the lance; a collar member adapted to be seated at least partially around the bore and opening on one side into the chamber, the collar having an inclined surface generally directed away from the outlet mouth of the blast pipe; and a ball adapted to be held in the chamber by the lance when passed through the valve into the blast pipe and adapted to run down the inclined surface of the collar into the bore upon withdrawal of the lance from the bore so as to close the bore and seal the valve assembly.

2. Apparatus as claimed in Claim 1 wherein the ball is of stainless steel.

3. Apparatus as claimed in Claim 1 or 2 wherein the ball is of spherical configuration.

4. Apparatus as claimed in any one of the preceding claims wherein the collar is of generally "U" shaped configuration in end elevation.

5. Apparatus as claimed in any one of the preceding claims, wherin the inclined surface is inclined at approximately 45° to the general axis of the bore passing through the chamber.

6. Apparatus as claimed in any one of the preceding claims wherein the bore passing through the chamber is provided with an internal annular shoulder adjacent to the inclined surface of the collar and on the side thereof away from the outlet mouth of the blast pipe, the internal shoulder having an internal diameter less than the diameter of the ball, the arrangement being such that the ball, upon running down the inclined surface of the collar sealingly engages with the shoulder to close the bore.

7. Blast furnace apparatus substantially as shown in and as hereinbefore described with referenc e to the accompanying drawing .

Drawing