SU1206314A1 - Tuyere for bottom blowing of metal - Google Patents

Description

1206314

2. The lance according to Clause I., distinguished- 3. The lance according to Clauses. 1 and 2, so that the helix is such that the coil has at least three entranced tubes connected to the path of the cooler. The coolant supply pipes are installed inside the steel pipe.

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This invention relates to metallurgy, in particular, to devices for blowing melts.

The purpose of the invention is to increase the stiffness of the tuyere.

FIG. 1 shows a lance, a general view, in section in FIG. 2 is a section A-A in FIG. 1.

The lance contains path 1 for supplying the reagent, path 2 for supplying the cooler, path 3 for discharging the cooler and the immersion nozzle 4 consisting of a steel pipe 5 and a separate reinforcement 6 located on the outer surface of the pipe 5 and made in the form of a multiple spiral with step In from copper cooled tubes connected to the coolant supply and discharge paths by tubes 7 located inside the steel pipe 5. Outside the steel pipe is protected with a refractory coating 8.

The lance works as follows.

The reagent from path 1 enters the immersion nozzle 4 and enters the melt. The refractory coating 8 on the outer surface of the steel pipe 5 is held by a spiral of copper tubes of reinforcement 6. The cooler from tract 2 through tubes 7 located inside the steel pipe 5 enters the tubes of spiral reinforcement 6 and flows through them upwards, cools them and leaves Tract 3 outlet cooler. Due to the cooling of the spiral tube, they do not lose their reinforcement capacity for the refractory coating of the immersion nozzle, even at very high temperatures of the blown hot metal (up to 1950 ° C), characteristic of oxidative blowing of stainless steel in an electric arc furnace.

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The need to perform multiple spirals is explained by a low flow rate of the cooler through one tube due to high hydraulic resistances with a large nozzle length. A multiple lead helix (consisting of several cooled tubes wound on a steel tube) allows an increase in the flow rate of the cooler in proportion to the number of entries. In addition, the hydraulic resistance in X1 of each tube (helix) is significantly reduced, as the number of turns of each individual helix decreases.

When the number of visits is less than three

the durability of the tuyere is significantly reduced, since the amount of coolant passed through the helix tubes is not enough to cool the tuyere. This leads to a boil of the cooler (water), the formation of scale and the subsequent burnout.

The optimum, from the point of view of fixing the refractory coating on the pipe with a spiral, is the ratio of the pitch of the helix h to the diameter of the cooled helix tube, in the range of 1.5-3.0. When the ratio h / j is less than 1.5, the gap between the tubes is too small and completely disappears at, 0. In this case, the refractory coating is adjacent to the tubes only on the 4th (outer) side, t, e. the reinforcement capacity of the helix is deteriorated. Therefore, the coiling step of the helix must ensure the application of refractory gasket around the cooled tubes. At a ratio h / (more than 3.0, the tubes are too KOI.S far from one another and the refractory coating is not well supported by the coil, it can peel off and wash out.

The consistency of the spiral pitch along the height of the immersed nozzle provides

, the same degree of fixing refractory packing.

The optimum ratio of the diameter of the steel pipe to the diameter of the cooled spiral tube is 6.0-10.0. At a ratio of less than 6.0, the winding of cooled tubes on a steel pipe is difficult due to the small bend radii, which leads to a decrease in the wall thickness of the cooled helix tube on the outer surface and, as a consequence, a decrease in the lance resistance due to mechanical damage. Increasing the ratio of the diameter of the steel pipe to the diameter of the cooled helix tube more than 10.0 is inefficient. This is sv. This is due to the fact that the maximum diameter of the outer pipe is limited by real constructive

06314 -.

values and a further increase in the ratio can only be due to a decrease in the diameter of the spiral tube. However, its reduction leads to

5 to increase the hydraulic resistance, decrease the amount of cooler and, as a result, decrease the durability.

Cooling tube connection

10 Spirgish with a coolant supply path with tubes installed inside a steel pipe provides increased durability due to more rational organization of the flow of the coolant through the spiral tubes in the bottom-up direction with M1 | the smallest possible outer diameter of the nozzle itself. At the same time, fixing of the refractory on the 20 bivki is improved.

Editor N. Yatsola Order 8653/27

Sost) speaker A.Protasov Tehred 3.Paly

Corrector;

Circulation 5 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PSh1 Patent, .g. Uzhgorod, st. Project, 4

Fug.2

Corrector; B. But ha

Claims (3)

1. FURMA FOR DEPTH METAL PURGEING containing a reagent supply path, cooler supply and exhaust paths and an immersion nozzle consisting of a steel pipe with spiral reinforcement on its outer surface and a refractory coating, characterized in that, in order to increase the lance resistance, the spiral reinforcement is made of cooled tubes, connected to the paths of supply and removal of the cooler, the ratio of the pitch of the spiral to the diameter of the cooled tube is 1.53.0, and the ratio of the diameter of the steel pipe to the diameter of the cooled tube is 6.0-10.0. 2. The lance on π. I, about t and h and - 3. Tuyere according to 1 and 2, this is due to the fact that the spiral is cooled by at least three removable tubes connected to the travel path. supply cooler tubes installed inside the steel pipe.