Blast furnace tuyere with replaceable liner

Claim 2

A liner assembly as recited in claim I wherein: said liner is composed of a metal having a substantially lower thermal conductance than that of the metal of which the tuyere is composed.

Claim 3

A liner assembly as recited in claim I or claim 2 wherein: said metallic liner has a main metallic liner portion terminating at a downstream nose portion; means on said liner for cooperating with the tuyere for providing a gas-tight seal between the inside surface of said tuyere and said liner, without attaching the liner to the tuyere; said means for providing said gas-tight seal comprising a metallic flange extending radially outwardly from said nose portion to a peripheral flange edge located at a predetermined radial distance from said nose portion at ambient temperature, said flange being continuous around the periphery of the liner nose portion; and said plurality of layers of refractory fibre paper disposed around said main liner portion are of a total paper thickness not substantially exceeding the radial dimension of said flange.

Claim 4

A liner assembly as recited in claim 3 and for use with a tubular, metallic, blast furnace tuyere having a nose portion with a predetermined inside diameter, and wherein: said flange on the liner is undivided and has a predetermined outside diameter which is less than the inside diameter of the tuyere's nose portion at ambient temperature but which expands during blast furnace operation so that the peripheral edge of said flange is in abutting relation with the inside surface of the tuyere's nose portion to provide a substantially gas-tight seal between the two nose portions during blast furnace operation.

Claim 5

A liner assembly as recited in claim 4 wherein: said peripheral edge on said flange is machined relatively smooth to enhance said seat.

Claim 6

A liner assembly as recited in any one of claims 3 to 5 for use with a tubular, metallic tuyere including a main tubular portion having an inside surface and terminating at a downstream nose portion, and wherein: said peripheral edge comprises means cooperating with said inside surface at the tuyere's nose portion to provide a substantially gas-tight seal between the two nose portions.

Claim 7

A liner assembly as recited in any one of claims 3 to 6 and for use with a tubular, metallic tuyere having a flared upstream end portion, and wherein: said metallic liner comprises a flared upstream end portion, connected to said main liner portion, and comprising means for cooperating with said flared, upstream end portion on the tuyere to provide a gas-tight seal between the two flared end portions, and means normally to urge said flared portion of the liner in a downstream direction.

Claim 8

A liner assembly as recited in any one of the preceding claims wherein: said tubular metallic liner is composed of a metallic material resistant to oxidation at temperature greater than 2000°F (1093°C) and having a melting point substantially exceeding 2500°F (1371°C).

Claim 9

A liner assembly as recited in any one of the preceding claims wherein: said metallic material has a melting point of at least about 4000°F (2204°C).

Claim 10

A liner assembly as recited in any one of the preceding claims wherein: said liner is removably mountable within said tuyere.

Claim 11

A liner assembly as recited in any one of the preceding claims in a blast furnace comprising: a tubular, metallic tuyere including a main tubular portion having an inside surface and terminating at a downstream nose portion.

Claim 12

A liner assembly as recited in claim 11 when dependent on claim 3 or any one claims 4 to 10 when dependent on claim 3, wherein: the inside surface at said nose portion of the tuyere is machined relatively smooth where it is abutted by the peripheral edge of the flange on the liner nose portion, to enhance the seal there.

Claim 13

A blast furnace comprising: a tubular, metallic tuyere including a main tubular portion terminating at a downstream nose portion; said main tubular portion having an inside surface; a plurality of layers of refractory fibre paper lining said inside surface; protective means for holding said layers of refractory fibre paper againt said inside surface and for minimising contact between said refractory fibre paper and the atmosphere within said blast furnace; and means on said protective means cooperating with the tuyere for providing a gas-tight seal between said protective means and the inside surface of said tuyere without attaching said protective means to the tuyere.

Claim 14

A blast furnace as recited in claim 13 wherein said protective means comprises: a tubular protective member which cooperates with said main tubular portion of the tuyere to sandwich therebetween said layers of refractory fibre paper.

Claim 15

A blast furnace as recited in claim 14 wherein: said tubular, protective member is composed of a metallic material substantially resistant to oxidation by the hot air blast introduced into said furnace and having a melting point exceeding the temperature to which the inside of the protective member is subjected during normal operation of the blast furnace.

Claim 16

A blast furnace as recited in claim 14 wherein: said tubular, protective member has a downstream nose portion and is composed of a metallic material having a melting point substantially exceeding the temperature to which the protective member's nose portion is subjected during normal operation of the blast furnace.

Claim 17

A blast furnace as recited in any one of claims 14 to 16 wherein: said tubular, protective member has an upstream end portion and a downstream nose portion; said tuyere has an upstream end portion; and said means for providing said gas-tight.seal comprises means at the downstream nose portion of the tuyere and the protective member for forming a gas-tight seal there.

Claim 18

A blast furnace as recited in claim 17 wherein said means for providing the gas-tight seal further comprises: means at the upstream end portions of the tuyere and the protective member for forming a gas-tight seal there.

Claim 19

A blast furnace as recited in any one of claims 13 to 18 wherein: said tubular, protective member comprises means cooperating with said tuyere to permit the removal of said protective member from within said tuyere without removing the tuyere from the blast furnace.

Claim 20

A blast furnace as recited in any one of claims 13 to 19 wherein: said tubular protective member is composed of a metallic material having a lower thermal conductance than the metal of which the tuyere is composed.

Claim 21

A blast furnace as recited in any one of claims 13 to 20 wherein: said tubular, protective member is removably mounted within said tuyere.

Claim 22

A blast furnace as recited in claim 21 further comprising: at least one other tubular protective member removably mountable within said tuyere as a replacement for said first recited tubular protective member; said other tubular protective member having an inside diameter different than that of said first recited tubular protective member so as to change the effective inside diameter of said tuyere when said other tubular member replaces the first recited tubular member within the tuyere; said other tubular protective member comprising means cooperating with said main tubular portion of the tuyere to sandwich therebetween said layers of refractory fibre paper.

Claim 23

A blast furnace as recited in claim 17 or any one of claims 18 to 22 when dependent on claim 17, wherein: said means at the downstream nose portion of the tubular, protective member comprises flange means extending radially outwardly therefrom for engaging with the inside surface of the tuyere's downstream nose portion; said flange means being continuous around the periphery of the tubular protective member's nose portion.