JPS60114689A - Spraying method of refractory in molten metal receiving vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for spraying refractories in a molten metal storage container, and more particularly to an improvement in a dry spraying method for refractories.

(Conventional technology) Generally, in containers containing molten metal.

In order to maintain a long lifespan under harsh conditions of use under high temperatures, refractory (c) refractories are repaired midway through use. There are 1 intermediate repair methods for such containers.
Repair by spraying refractories has been widely adopted from the viewpoint of improving the working environment, construction efficiency, and construction cost. Then,
A wet method and a dry method are used for spraying refractories on the inner wall of a container, but in the wet method, the refractory slurry from side 1 clogs the spraying device, and the refractory sprayed on the construction surface The dry method is mainly used because of the large loss of refractories as the refractories flow down and the quality of the finished product after construction is poor.

However, spraying of refractories using this dry method cannot sufficiently suppress the generation of dust from the refractories on the surface of the construction object, and there is a lot of band loss (repulsion falling) of the refractories. Construction efficiency due to poor mixing of auxiliary agents and finish due to peeling of the surface of the construction work') fr? There are drawbacks such as being too generous. Therefore.

In order to solve the problems of the dry spraying method described above, for example, as in Japanese Utility Model Publication No. 52-9236, a method has been proposed in which swirling motion is applied to the refractory powder particles at the base of the nozzle tip.
A spraying method using a spray nozzle (hereinafter simply referred to as a ring-type nozzle) equipped with a water addition mixer having a ring with a plurality of small ejection holes has been carried out.

This spraying method using a ring type nozzle involves applying a swirling motion to the powder while supplying water to the powder with the nozzle,
Additionally, by blowing in secondary air.

By promoting the above-mentioned swirling motion and promoting the mixing of water and refractories, it is possible to remove dust and prevent band loss to some extent, but simply imparting swirling motion to the powder will definitely prevent dust generation. as well as deterring.

It has not yet been possible to prevent adhesive band loss of refractory material on the surface of a construction body and to improve construction efficiency and finishing accuracy.

(Object of the Invention) The present invention is a spraying method that sufficiently suppresses dust generation, which are the drawbacks of the conventional spraying methods described above, reduces glue band loss on the surface of a construction object, and improves construction efficiency and finishing accuracy of the construction surface. Its feature is the supply pressure P of the primary gas that supplies the + i4 fire powder.

is 1 to 3 KF//ca, and the supply pressure P1 of the negative gas and the supply pressure P2 of the secondary gas are P2/P+=1
．． 2 to 3.0, this is an extremely excellent method for spraying refractories.

(Structure and operation of the invention) A method for spraying refractories according to the present invention will be described in detail below.

In the dry method/spraying method of refractories, in order to remove dust from the surface of the construction object and prevent band loss, it is possible to reduce the properties to some extent by adding sufficient water to the refractory powder particles that are barking. This is because the distance from the water supply point to the spout at the tip is short.

The printed material and water or additives cannot be mixed sufficiently,
If the nozzle is clogged due to considerable dust and reno (and loss) and uneven water content in the refractory, the refractory will flow down on the surface of the construction body. Therefore, the present invention focuses on the importance of suppressing dust generation during spraying and reband loss on the surface of the construction object when dry spraying refractories, and moreover, By sufficiently mixing water and refractories in a short distance from the base of the nozzle tip to the spout at the tip, without increasing the amount of water added, rather with an extremely small range of water addition, the above-mentioned dust generation and construction The present invention is based on the discovery that it is possible to extremely effectively suppress adhesive band loss on the body surface. In addition, by reducing the loss of refractories during spraying, the adhesion rate of refractories has been improved and construction efficiency has been improved, as well as more uniform humidity control and improved finishing accuracy on the surface of the construction object. It is based on

In this way, one aspect of the present invention is to mix the hydrated refractory powder and the refractory supply in order to mix the added water sufficiently and evenly while the refractory powder flow passes through a very short distance in the nozzle. In the flow of primary gas (hereinafter simply referred to as primary air),
A secondary gas (hereinafter simply referred to as secondary air) is pressurized to impart turbulence to the mixed flow of the primary air and surface-1 large powder inside the vicinity of the nozzle light trail, thereby obtaining excellent uniform mixing; Effective spraying of refractories was achieved.

That is, the method for spraying refractories according to the present invention, as shown in the experimental results in FIG. We ensure a sufficient supply of material and carry out spraying work in a short time.
Moreover, it prevents clogging in the nozzle and improves the adhesion rate of large objects. It's simple, simply.

Since there is a limit to the adhesion rate when the refractory is supplied only at the air pressure P1, as shown in FIG.
1 and secondary air pressure P2 and f P27 Pl = 1.2 ~
30, and by pressurizing secondary air through a short pipe inserted inside the nozzle tip, turbulence is added to the mixed flow of secondary air and refractory powder inside the nozzle tip. Thoroughly mix the water and refractory powder.

Mata 1 As shown in Figs. 1 and 2, the spraying method for refractories according to the present invention is based on simply optimizing the -order air pressure or satisfying only P2/"l, which does not lead to the onset of fire resistance problems. In order to prevent reband loss and improve the item 1 coverage rate when spraying refractories, the negative air pressure P is in the range of 1 to 3 Kg/Cni, and P2/P is -1, 2 to 3.0. By satisfying both of the above, the turbulence imparted to the mixed flow of the refractory powder is strengthened, and the refractory and additive water or auxiliary agent are sufficiently mixed.Furthermore, , refractory supply - next air pressure P1.

When it is less than 1.0 Kfj/cm, it becomes impossible to fill and spray the refractory into the refractory transport pipe or the spray nozzle.

Furthermore, even if spraying becomes possible, the amount of refractory supplied must be extremely small to prevent clogging, which requires a long time for construction. On the other hand, when it exceeds 3.1 K9/cyf, the discharge jet becomes strong and reband loss occurs.

occurs frequently.

Furthermore, if the ratio of P2/P is less than -2, the refractory and moisture will not be mixed uniformly at the tip of the spray nozzle,
This leads to band loss and dust generation due to falling refractory material, P2
/P, is 5. If it is thicker than O, the jet of refractory discharged from the surface J of the nozzle tip will become stronger, resulting in frequent band loss of the refractory on the spraying surface. In this way, in order to suppress dust generation, reband loss, etc. and improve construction efficiency in spraying refractories, the -second air pressure P should be set to 1.5-2.5.
Kg/ca, and the ratio of the secondary air pressure P1 to the secondary air pressure P2 is p2/p, = 1.5 to 2.0, since spraying can be performed more effectively.

The primary and secondary gases used in the above-mentioned spraying may be, for example, air, nitrogen, Ar, or the like.

Also, what is the spraying distance to the refractory powder when spraying?

200 to 700, and the added moisture content of this refractory is also 10 to 700.
It is desirable to set it to 20%.

Here, if the spraying distance is less than 200 rnm, ribbon loss and dust generation will occur, and at the same time, the spreadability of the material will be poor and the spraying time will be longer. On the other hand, if it exceeds 700 n1m, the jet of refractory discharged from the tip of the nozzle will diffuse, making it difficult to add flavor.

Regarding moisture, if the moisture content is less than 10%, the moisture content in the refractory will be low9, reband loss, and dust generation will occur easily.On the other hand, if the moisture content is more than 21%, the nozzle may become clogged or sprayed due to excessive moisture. Peeling due to explosion during drying and refractory flow is more likely to occur.

(Example) Next, an example of the method for spraying refractories according to the present invention will be described based on the drawings.

FIG. 3 shows a spray nozzle having a vibrating short tube at the nozzle tip, and FIG. 4 shows a spray nozzle having a fixed short tube at the nozzle tip.

First, in FIG. 3, numeral 1 is a cylinder such as a steel pipe of an appropriate diameter, and has a restrictor 9 portion 1a at its tip to form a flow path for the refractory. For example, by suppressing the primary air pressure P1 connected to a refractory powder pumping device (not shown), a mixed flow of refractory and primary air is created by the arrow 2. supplied in the direction.

A plurality of water supply holes 3 are bored in appropriate parts of the cylinder 1, and a water supply header 4 communicating with the water supply holes 3 and a water supply pipe 5 fixed to the water supply head 4 are provided. Water is added to the mixed stream of refractory powder and primary air. In addition, secondary air is further pressurized into the water-added mixed flow through an air supply pipe 8 connected to a secondary air pressure inlet 6 bored at the tip and an air supply hose 7. This press-in secondary air is supplied by a hard cloth, for example, provided inside the cylinder l between the straight pipe part and the tip aperture 9 part la.

Alternatively, the vibrating short tube 9 made of hard rubber or the like is press-fitted into the inside through the gap lO between the inner wall surface of the throttle 9 portion 1a and the short tube 9.

By press-fitting the secondary air, turbulence is imparted to the mixed flow of the refractory and primary air supplied near the tip 11 of the short pipe 9 in the two directions of the arrows.

Further, as shown in Fig. 4, instead of the hard comb, a non-vibrating short pipe 9 made of, for example, a steel pipe or ceramic may be used, and it is possible to sufficiently impart turbulence to the mixed flow of refractories. did it.

(-Effect of the invention) Next, using a spray nozzle not shown in FIGS.
%, primary air pressure P with the same water content and spraying distance as Kempo Example 1, which was sprayed at a spraying distance of 350 rtrm,
2. Table 1 shows a comparison with the conventional method in which P2/P1 is outside the scope of this method for OKg/cnj.

It can be seen that this method is excellent as a spraying method because there is no dust generation, no adhesive band loss on the construction surface, no falling of refractories due to falling down, etc.

Table 1 As mentioned above, by using the single method in dry spraying, it is possible to prevent clogging of the piping for transporting large objects and nozzles 9, as well as reband loss and dust generation.

This is an excellent method of spraying refractories that can solve problems such as falling refractories due to falling, and has extremely high construction efficiency due to improved adhesion to the construction surface, and can be applied to a wide range of containers lined with refractories. It is.

[Brief explanation of drawings]

FIG. 1 shows the relationship between the refractory supply-sub-air pressure P and the adhesion rate. FIG. 2 shows the relationship between the ratio of the secondary air pressure P2 and the primary air pressure P1 and the adhesion rate. Fig. 3 shows a schematic cross-sectional view of a spray nozzle in which a vibrating short pipe is provided at the nozzle tip, and Fig. 4 shows a schematic cross-sectional view of a spray nozzle in which a fixed short pipe is provided in the nozzle tip. . l...Cylinder Pl...-Secondary air pressure P2...Secondary air pressure 3...Water supply hole 4...Water supply header 5...Water supply pipe 6...Secondary air pressure inlet 7...Air supply header =8...
・Air supply pipe 9...Short pipe Figure 1 2nd fork

Claims (1)

[Claims] In a refractory spraying method in which a water supply port is drilled at the base of a nozzle tip to add water to a mixed fluid of refractory powder and a primary gas, and then a secondary gas is pressurized into the mixed fluid, the supply of the fire gas. The pressure P1 is 10 to 3.0 KvcnI, and the supply pressure P of fire gas and the supply pressure P2 of secondary gas are p2
A method for spraying refractories in a molten metal storage container, characterized in that /p is 1.2 to 30.