JPS6229101B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies to various types of kilns (e.g., continuous steelmaking furnaces, top-blown, bottom-blown converters, Q-BOP, AOD) constructed with refractories.
Furnaces, DH furnaces, RH furnaces, special smelting furnaces, ladles, pails,
Adding thermosetting resin to refractories, especially refractories, for hot or cold spraying of electric furnaces, pig iron trucks, pig iron mixed furnaces, reduction furnaces, blast furnaces, hot blast furnaces, non-ferrous metal smelting furnaces, rotary kilns, coke ovens, etc. The present invention relates to a refractory spray pipe used in a spray device for effectively depositing spray refractories.

Traditionally, hot spraying repairs have been carried out on various types of kilns. These methods are classified into dry methods, wet methods, etc., depending on the timing of water addition, but both are thought to follow the adhesion process described below. In other words, in the hot adhesion process of these refractory materials, in view of the phenomenon that in normal spraying, there is no adhesion at the beginning of the spraying, but the adhesion suddenly starts after a certain point, firstly, the mixed water is applied to the sprayed surface. is cooled until the water vapor pressure falls below the adhesion strength of the material, after which adhesion starts from the fine powder portion of the material, followed by full-fledged adhesion of the material. This sprayed construction body is dried and hardened by the heat retained in the non-sprayed refractory after the spraying is finished or the spray nozzle is moved to another location. The above is considered to be the adhesion process of conventional spray material. In view of this process, conventional spraying has two major drawbacks. One is the cooling of the surface of the non-sprayed refractories, which is an essential factor for adhesion, and this generates severe thermal stress on the sprayed refractories, causing further damage. The sprayed material is wasted as ineffective material while the sprayed refractory cools until it is suitable for deposition. On the other hand, from the perspective of the sprayed material, water is essential for improving the adhesion rate, improving strength, and transporting the sprayed material without generating dust by imparting plasticity to the spraying material or causing a reaction with the hardening agent. The above-mentioned drawbacks were unavoidable.

As a result of research to overcome the above drawbacks, the present inventor has
By adding a thermosetting resin to the refractory material, we have succeeded in developing a refractory material that has a high adhesion rate and can prevent damage due to cooling. The preferable adhesion process for the above-mentioned sprayed refractory is that in hot conditions, the thermosetting resin in the sprayed material is softened by the heat retained in the kiln, etc. while flying from the outlet of the spraying pipe to the furnace wall. The sprayed material collides with and adheres to the refractory to be sprayed, and then the thermosetting resin hardens due to the heat retained by the refractory to be sprayed, and is fixed to the refractory to be sprayed.
Further, by repeating this process of carbonization, a strong carbon bond can be obtained.In cold conditions, the furnace wall surface is at room temperature, so the necessary amount of heat is supplied to the material to be sprayed before it adheres to the furnace wall during spraying. As a result, the thermosetting resin in the sprayed material softens, and the sprayed material collides with and adheres to the sprayed refractory. Thereafter, by heating the spray material and the refractory to be sprayed, the thermosetting resin is cured and carbonized to adhere to the refractory to be sprayed, thereby obtaining a carbon bond spray body.

The present invention provides a spray pipe structure that allows the spray material to be efficiently attached to the furnace wall surface during spray construction, that is, it has a structure that is sufficient to soften the spray refractory to the extent necessary for sufficient adhesion during flight. It is an object of the present invention to provide a blowing pipe structure for use when atmospheric heat or retained heat of a workpiece cannot be obtained.

In order to achieve the purpose, the refractory spray pipe of the present invention is a spray pipe used for spraying a refractory containing a thermosetting resin onto the surface of a furnace wall to be constructed. It is characterized by consisting of a rear pipe having a heated gas mixing mechanism for mixing heated gas into the refractory, and a front pipe having a cooling mechanism arranged in the pipe.

Note that hot air, heated steam, inert gas, etc. can be considered as the heated gas.

The above-mentioned spray pipe will be described in detail below.

FIG. 1 shows the entirety of a spraying device having a spraying pipe according to the present invention, which generally includes:
A refractory tank 1 filled with a refractory made by adding a thermosetting resin to a refractory material, a machine frame 2 on which the tank is placed, and a refractory feed mechanism that cuts out a fixed amount of refractory from the refractory tank 1. 3. A blowing pipe 4 that communicates with the feeding mechanism and brings the refractory to the required surface in the furnace.
It consists of

The spray nozzle structure which constitutes the gist of the present invention in the above configuration is shown in detail in FIGS. The end is the main body of the blowing pipe which faces the work surface 12 of the furnace wall in an open state, and 7 is a heating gas mixing mechanism provided in the middle of the blowing pipe 5. Various forms and mounting methods of the heated gas mixing mechanism 7 are conceivable, but in this embodiment, a sealed annular cylinder 8 with both ends closed is disposed concentrically at a desired midway point of the blowpipe main body 5, and a sealed annular cylinder 8 is used inside the annular cylinder. The main body 5 of the blowing pipe has a front pipe 5-a and a rear pipe 5-b in order to allow heated gas to flow into the pipe from the annular cylinder 8. Furthermore, the tip of the rear pipe 5-b is tapered to form a heated gas mixing passage 10 between it and the rear end of the front pipe 5-a.

In addition, the blowing pipe main body 5 surrounds the front pipe 5-a over almost the entire length, and prevents excessive temperature rise of the refractory passing through the pipe (excessive heating can be avoided before adhesion to the furnace wall surface). It has a water cooling pipe 11 to prevent refractories from adhering to the inner surface (which may cause adhesion of refractories to the inner surface), and 15 is a water supply port for supplying the water cooling pipe;
13 is a water outlet for discharging water after circulating through the water cooling pipe 11.

Incidentally, instead of providing a cooling device as described above, adhesion of the refractory can be prevented by blowing heated gas through a porous pipe to float the refractory as shown in FIG.

Next, the operation of the spraying device equipped with the refractory spray pipe according to the present invention will be described.

First, the refractory feed mechanism 2 is driven to continuously feed a required amount of refractory from the cooled refractory tank 1 into the spray pipe body 5. On the other hand, heated gas flows into the spray pipe 5 through the annular cylinder 8 and the heated gas mixing passage 10, mixes into the spray refractory being transferred through the pipe, and causes the thermosetting gas contained in the refractory to Heat with resin. Since the spray pipe main body 5 is water-cooled by the water-cooled pipe 11, the refractory is brought to the spray end of the spray pipe 5 without excessively increasing its temperature. Thereafter, the refractory is sprayed from the spraying end of the spray pipe main body 5 toward the surface to be constructed of the furnace wall. granular,
The sprayed refractory that is sprayed onto the lining surface and collides with the lining surface (semi-dry or dry, so it is effectively heated by contact with the heating gas), effectively adheres to the lining surface, and is then heated by the heating gas or the sprayed refractory by the heating device. The thermosetting resin hardens and carbonizes due to the heat retained by the object, making it adhere to the lining. By repeating this process, a strong carbon bond spray body 14 is obtained.

As described above, the spray pipe according to the present invention has the following effects.

Using heated gas, refractories can be efficiently attached to the furnace wall even in cold conditions.

The above effects can be achieved simply by attaching the annular cylinder midway through the spray pipe.

Even if the spray refractory is heated inside the spray pipe, it will not adhere to the inner wall of the spray pipe or become clogged.

[Brief explanation of the drawing]

Fig. 1 is an overall view of a spraying device equipped with a spraying pipe according to the present invention, Fig. 2 is an enlarged longitudinal cross-sectional view of the spraying pipe, Fig. 3 is a cross-sectional view taken along the line of Fig. 2, and Fig. 4 is a FIG. 2 is a cross-sectional view along the line, and FIG. 5 is an explanatory view of another embodiment of the means for preventing the adhesion of refractories to the spray pipe. 1: Refractory tank, 5: Shot pipe body, 5-
a: front pipe, 5-b: rear pipe, 6: coupling, 7: heated gas mixing mechanism, 8: annular cylinder, 9: heated gas inlet, 10: heated gas mixing passage, 11: water cooling pipe.

Claims (1)

[Claims] 1 A spray pipe used for spraying a refractory containing a thermosetting resin onto the surface of a furnace wall to be constructed, and a rear portion having a heated gas mixing mechanism that mixes heated gas into the refractory being transferred within the pipe. A refractory spray pipe characterized by consisting of a pipe and a front pipe with a cooling mechanism arranged on the pipe.