JPS6229102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies to various types of kilns constructed with refractories (e.g., continuous steelmaking furnaces, top-blown, bottom-blown converters, Q-BOP furnaces, etc.).
Special smelting furnaces such as AOD furnace, DH furnace, RH furnace, ladle, gutter, electric furnace, pig iron mixing car, pig iron mixing furnace, reduction furnace, blast furnace, hot blast furnace, non-ferrous metal smelting furnace, rotary kiln,
The present invention relates to a refractory spray pipe used in a spray device for effectively depositing hot or cold spray refractories, particularly spray refractories made by adding a thermosetting resin to a refractory material, in coke ovens, etc.

Conventionally, hot spraying repairs have been carried out on various types of furnaces. 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, the hot adhesion process of these refractory materials is
Considering that in normal spraying, there is a phenomenon that no adhesion occurs at the beginning of the spraying, but suddenly starts adhesion after a certain point, the mixed water is first applied to the sprayed surface until the water vapor pressure becomes less than the adhesion strength of the material. cool,
After that, the fine powder part of the material starts to adhere, and then the material starts to adhere in earnest. This sprayed construction body is
After spraying is completed or the spray nozzle is moved to another location, the refractory to be sprayed dries and hardens due to the heat retained in it. The above is considered to be the conventional process of adhesion of spray material. In view of this process, conventional spraying has two major drawbacks. One is the cooling of the surface of the refractory to be sprayed, which is an essential factor for adhesion, and this generates severe thermal stress on the refractory to be sprayed, causing further damage. While the sprayed refractory cools until it is suitable for deposition, the sprayed material is wasted as ineffective material. 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 giving the spraying material plasticity 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 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 spray body can be obtained.

That is, it is preferable that the refractory for spraying be softened immediately before attachment, and that the thermosetting resin in the refractory for spraying should be softened immediately before adhesion, and the thermosetting resin in the refractory for spraying should be softened immediately before it is attached. It is important to prevent the material from becoming soft. On the other hand, in the cold process, the furnace is at room temperature, so there is no need to worry about softening due to air around the furnace, but as in the hot process, it is preferable that the sprayed refractory softens just before it is deposited. The present invention provides a refractory spray pipe structure used in the work of attaching such refractories to the required furnace wall surface, that is, an atmosphere with enough ambient air to soften the spray refractories to the extent necessary for sufficient adhesion during flight. Another object of the present invention is to provide a pipe structure for use when the retained heat of the object to be blown 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 a workpiece surface such as a furnace wall brick. The present invention is characterized in that a mechanism for generating heated gas that heats the blowing end and the surface to be worked is provided at the blowing end of the pipe.

The above-mentioned spray pipe will be explained 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. A blowing pipe main body has an open end facing the work surface of the furnace wall, and 7 is a heated gas generating mechanism provided at the blowing end of the blowing pipe main body 5. Note that the heating generating mechanism 7 is not necessarily limited to the blowing end of the blowing pipe main body 5, and may be provided in the middle of the pipe. Various forms of the heated gas generation mechanism 7 can be considered, but in the embodiment, from the base end of the spray pipe main body 5 to approximately the spray end 5.
a pair of fuel gas supply pipes 8 extending to a point a, a jet hood 9 provided around the gas jet port 8a of the same supply pipe, and a jet hood 9 arranged concentrically around the blow end 5a of the jet pipe main body 5. It is shown as having a configuration consisting of a blowing end hood 10 that integrally surrounds the blowing end, gas jetting port 8a, and jetting port hood 9, and a combustion air inflow hole 11 provided at the periphery of the tip of the blowing end hood 10. . Furthermore, in the above structure, in order to prevent refractories from adhering to the inner surface of the blowing end of the blowing pipe 5a due to heating by combustion gas, the insulating pipe 1
2 are provided concentrically, and an air insulation layer 13 is formed between the blowing end and the insulation pipe 12. Note that instead of the heat insulating pipe 12, a heat insulating material may be applied to the spray end.

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. Since the interior of the blast pipe body 5 is at room temperature, the refractory is brought to the blast end of the blast pipe body 5 without increasing the temperature. Thereafter, the refractory is sprayed from the spray end of the spray pipe main body 5 toward the surface to be constructed of the furnace wall. At this time, the fuel gas from the fuel gas feed pipe 8 is ignited by an ignition gas burner (not shown). The combustion gas generated by the combustion is sent to the spray pipe main body 5.
The sprayed refractory 5a and the refractory to be installed (lining) are heated, whereby the sprayed refractory is softened by the heat possessed by the refractory to be installed 12 and the sprayed end 5a during flight, and the sprayed refractory collides with the lining surface. adhere to. Thereafter, the thermosetting resin hardens and carbonizes due to the heat retained by the sprayed refractory, thereby fixing it to the lining. By repeating this process, a strong carbon bond spray body can be obtained. In addition, if sufficient retained heat cannot be given to the sprayed refractory, the sprayed refractory is softened during flight using the method described above, and this process of colliding and adhering to the sprayed refractory is repeated, and the sprayed refractory is laminated and adhered. and complete the lining. Thereafter, the lining is hardened and further carbonized by preheating before using the kiln to obtain a strong carbon bond sprayed body.

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

(1) Using heated combustion gas, refractories can be efficiently attached to the furnace wall even in the cold.

(2) The above effects can be achieved by attaching a heated gas generating mechanism with a simple structure to the blowing end of the blowing pipe.

(3) Even if the sprayed 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 spray device equipped with a spray pipe according to the present invention, FIG. 2 is an enlarged vertical sectional view of the same spray pipe, and FIG. 3 is a cross-sectional view taken along the line shown in FIG. 2.

Claims (1)

[Claims] 1 A spray pipe used to spray a refractory containing a thermosetting resin onto a work surface such as a furnace wall brick, and a mechanism that generates heated gas that heats the blow end of the pipe and the work surface. A refractory spray pipe, characterized in that the following is provided at the spray end of the pipe.