JPS61175476A - Method of molding refractory body and lance for flame spraying granular heat-generating oxidation material - 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 The present invention relates to a method for forming a refractory body, and more particularly, the present invention relates to a method for forming a refractory body, and more particularly, a mixture of exothermic oxidizing granules and refractory granules is thermally sprayed onto a work surface in a flammable gas. A method for forming a refractory on a surface, wherein the material to be thermally sprayed is transported along a lance to the head of the lance and the mixture is discharged, and the conditions at the time of discharge are such that the oxidizing particles are combustible. The present invention relates to a method in which heat is generated by reacting with a reactive gas, and at least the surface of the sprayed refractory particles is melted by the heat to form the refractory body.

The present invention relates to a thermal spray lance, and more specifically,
The present invention relates to a lance for spraying granules of exothermic oxidizing material and granules of refractory material in a combustible gas, the lance having a head for discharging the granular material and suitable for the method described above.

This type of method is particularly suitable for repairing furnaces and other refractory equipment at high temperatures. The above method may also be useful when forming refractory elements, such as when coating with refractory metals or other refractory materials, and especially when forming refractory linings in areas prone to corrosion. Beneficial.

When refurbishing a furnace, it is preferable, and preferably, to perform the refurbishment at the operating temperature of the furnace. Furthermore, when repairing a glass melting furnace structure or the like, the repair may be performed while the furnace is still operating. In either case, it is desirable that repair work at high temperatures be completed in a short time, to avoid problems associated with cooling and reheating the repaired equipment as much as possible, and to allow commercial work to resume as soon as possible. .

Previous experience has shown that this type of method has problems in reliably forming durable refractory welds, which may lead to defects in the formed refractories. Many studies have been conducted on the subject. Laboratory tests of cross-sections of welds have shown that in many cases, welded refractory materials exhibit some degree of layering. The reason for this layering is that a weld of any thickness is made up of multiple weld layers on the working surface, but as the surface of adjacent weld layers cools,
This is thought to be due to the occurrence of non-uniform areas in the refractory material at the boundary between adjacent welding material layers.

When layering occurs due to this lack of homogeneity, the strength of the refractory decreases. When the furnace is activated, thermal gradients are created in the repaired area, resulting in differential thermal distortion of adjacent layers and, over time, delamination of the refractory material. In other words, it is necessary to perform repair work, etc. again. Depending on various conditions, serious problems other than those described above may occur. For example, in the case of a glass melting furnace, any refractory material that flakes and falls into the molten glass can seriously contaminate the contents of the furnace.

From what we have observed so far, the degree of layering depends on the number of weld layers required for the work, and thermal theory, the required number of weld layers depends on the rate of formation of material on the work surface and the approximate amount of weld resistance. Ru. The theoretical formation rate of refractory on the working surface is:
To match the rate of discharge of material from the lance and therefore reduce the number of layers required to grow the refractory weld layer to a given thickness and reduce stratification, injecting the weld material at a high discharge rate. is desirable.

It is basically impossible to increase the material flow rate above a certain speed in any nozzle.

If the discharge rate of the material is too high, the lance is likely to become clogged because the granules become overheated during transportation due to friction between themselves and the lance passage walls.

When a gas containing oxygen, such as air, is used as the transport gas, if blockage occurs, the oxidizing particles will spontaneously ignite. In addition, increasing the size of the nozzle exit beyond a certain limit creates a problem in that the yield ratio of the process, ie, the proportion of the sprayed material remaining as a refractory on the work surface, tends to decrease.

The reason for this is believed to be that the rate of ambient air entrained in the thermal spray jet stream is too high, thereby cooling and diluting the thermal spray stream.

The present invention aims to provide a method for solving the above problems.

According to the present invention, there is provided a method for spraying a mixture of exothermic oxidizing granules and refractory granules onto a work surface in a combustible gas to form a refractory body on the surface, the method comprising: The thermal spraying material is transported to the lance head and the mixture is discharged, and the conditions at the time of discharge are such that the oxidizing particles react with the combustible gas to generate heat, and the heat sprays the refractory particles. In a method set such that at least the surface of the body is melted to form the refractory body, a mixture of oxidizing particles and refractory particles is thermally sprayed in a flammable gas from a group of nozzle outlets, and during the thermal spraying, The total nozzle exit area is 1 square c.
thicker than 50Kf per hour for m, above 1
Viewing the spaced arrangement of the nozzle outlets of the group from the end side, each nozzle outlet has a positive impact on itself or on the other nozzle outlets of said j11 with respect to the first other nozzle outlet of said group. a distance of not more than 3 times the minimum diameter of the cross-section, and a distance of not more than 8 times the minimum diameter of the cross-section of itself or of said second other nozzle outlet from said second other nozzle outlet of said group; The nozzle exit centers of at least some of the nozzles in the group are set to form vertices of a virtual polygon.

According to the present invention, in addition to the nozzles constituting the above group, a lance having one or more nozzles arranged in a manner other than the above may also be used. However, in order to effectively prevent the stratification phenomenon, it is preferable that the nozzle group is composed of all the nozzles located within the lance.

According to the method of the present invention, it has been confirmed that almost no stratification phenomenon occurs in the refractory welded layer. In fact, even if a fairly thick weld layer is formed by the Q-sprayed layer from multiple passages of the lance on the work surface, a weld layer with a generally homogeneous structure can be formed. Therefore, it is thought that the thermal factor can be improved by combining the nozzle arrangement and high discharge rate described above.

When repairing high temperature refractory surfaces, lance effluents initially act to locally increase the temperature of the surface, often preventing the thermal spray material from properly adhering to the surface. Good adhesion will only begin once the temperature of the work surface has risen to an appropriate level. When working according to the method of the invention,
Due to the high evacuation rate and the relatively close proximity of the jets from different nozzles, heating of the surface occurs rapidly. Due to the adjacency of the jet streams, each jet stream is shielded to some extent from the surrounding atmosphere by the other jet streams and is therefore more susceptible to combustion and high temperatures.

Also, the refractory material forming a working surface is heated to a relatively large extent and, during operation, a certain area of the working surface is surrounded by a hot jet flow; therefore, the degree of cooling of said surface is low. It must also be maintained at a sufficiently high temperature to not only allow proper adhesion of the refractory but also to maintain a homogeneous refractory weld structure formed by successive weld layers of the lance in each given area of the work surface. I can do it.

In order to obtain good results as described above, there are no strict limitations on the manner in which the lance is moved relative to the work surface when forming the refractory weld layer. For example, if a crack in a fireproof wall is deep, it can be repaired by moving a lance along the crack and gradually forming a weld layer of a predetermined thickness along the crack, or by moving the lance along the entire length of the crack. It is also possible to form a desired welded layer by moving it back and forth several times. Conventionally known methods are unable to obtain satisfactory work results in any of the above cases, whereas by employing the method of the present invention, repairs can be performed with high quality in any of the above cases.

According to the embodiment of the present invention, the average gas discharge speed from each nozzle in the group is set such that the difference is within 101 compared to the average gas discharge speed from each other nozzle in the group. By employing this feature, the formation rate of the refractory body can be further increased. If the average velocity of the jet stream from a nozzle is much higher than the average velocity of adjacent jet streams, there is a risk that the jet stream will entrain material from its periphery. In that case, the material ignites too quickly in the high velocity jet flow, reducing the deposition or formation rate.

Further, the spaced apart arrangement state of the nozzles in the group may be such that when the nozzle outlets in the group are viewed from the end side, each nozzle outlet in the group has a distance between itself and the first other nozzle outlet. Alternatively, it is preferable that the first other nozzle outlet is separated by a distance that is twice or less the minimum diameter of the cross section of the first other nozzle outlet. Adoption of this feature of the present invention has the advantage of promoting heat concentration on the surface being worked on, as well as restricting dilution of the jet stream from the nozzle outlet by the surrounding outside air. The advantage is that the reaction conditions are further improved and, as a result, the formation rate of the refractory is further improved.

Further, the spaced arrangement of the nozzles in the group is such that when the nozzle outlets in the group are viewed from the end side, each nozzle outlet in the group has no relation to itself or to the other nozzle outlets in the group. Advantageously, they are spaced apart by a distance at least equal to the minimum diameter of the cross-section of each other outlet.

The main advantages of adopting this feature of the invention include:
The advantage arises that the material jets from the nozzles are less likely to interfere with each other during their flight towards the work surface. This further improves the oxidation reaction during thermal spraying and promotes the formation of a uniform, high-quality refractory.

According to an embodiment of the invention, the nozzle group for spraying the granular mixture comprises at least two rows of spaced apart nozzle outlets. Such a nozzle arrangement is suitable for spraying over very large areas of the work surface. Furthermore, since the spacing between the rows of nozzle outlets can be relatively easily changed to increase the sprayed area, the heating condition does not become too intense. In the above arrangement, the spacing between the nozzle exit rows is relatively wide (8% of the minimum nozzle exit diameter).
It is suitable for forming a welded layer of a refractory material such as silica, which has a relatively low melting temperature. If the working temperature is particularly high, the reactions in the sprayed material can cause significant heat concentrations, softening the refractory material that has just been welded to the surface to the extent that it flows away from the area where it was sprayed, thus preventing the formation of refractories. It has been found that this has an adverse effect on the ratio. By appropriately spacing the rows of nozzle outlets to match the melting temperature of the sprayed refractory material, the material is viscous enough to remain in place after being welded, and the mixture is sprayed from the nozzle outlets. It is possible to prevent the above phenomenon from occurring when It is also possible to move the nozzle relative to the work surface, in which case l-! Since the jet stream from the Nenana nozzle is sprayed first, and then the jet stream from the other nozzle row is sprayed, the work surface can be heated effectively. It has been found that by appropriately spacing the nozzle rows, the refractory material immediately deposited from one jet stream remains at least partially molten when the next row is sprayed. . As a result, the refractory material from the next row is welded on top of the previously deposited material without any distinct layering occurring. For example, a jet stream can be sprayed from two rows of three nozzles, and if the die has a "6" face, the nozzle exits are all circular and have the same diameter, and the nozzles in each row The edges of the nozzle outlets are spaced apart by no more than 3 times the diameter, and the rows are spaced apart by no more than 8 times the diameter between the edges of the nozzle outlets.

In an embodiment of the present invention, the nozzle group includes at least one inner nozzle and a plurality of peripheral nozzles, the center of the outlet of the peripheral nozzle forms the vertex of the virtual polygon, and the outlet of the inner nozzle is located inside the above polygon. Such an arrangement is particularly suitable for relatively intense heating of the work surface for spraying high melting point refractory materials such as alumina, magnesia, zirconia, etc.

When operating with the method of the embodiment of the invention, the jet of material sprayed from the inner nozzle outlet is at least partially surrounded by the jet of material sprayed from the peripheral nozzle outlet.

The presence of jet streams from suitably spaced peripheral nozzle outlets provides a screening effect, suppressing the escape of particulates from the inner stream into the surrounding atmosphere, resulting in relatively low temperatures.
It has been found that dilution of the internal flow by ambient air can be regulated. Further, the peripheral flow portion is similarly protected by the inner flow, and particulate material is prevented from flowing out into the surrounding outside air or being diluted by the outside air. The extent to which the outflow of granular materials into the surrounding air and the dilution of the jet stream can be suppressed is as follows:
Depends on screen effects due to peripheral flow. It is preferable that the linear spacing between the outlets of adjacent peripheral nozzles is not more than three times the minimum diameter of any one of the adjacent peripheral nozzle outlets, since this can promote the screen effect.

In accordance with embodiments of the invention, the linear spacing between the outlet of each peripheral nozzle and the outlet of its closest inner nozzle is no more than three times the smallest diameter of one of those nozzle outlets.

By adopting this feature, the conditions for the oxidation reaction that takes place during thermal spraying can be controlled easily and in good conditions, and the work surface can be strongly heated to weld the highly refractory material, increasing the formation ratio of the refractory material and A refractory body of very high quality can be formed.

It has been found that if the single nozzle exit size is increased beyond practical tolerances, the injected material will not flow well. In reality, material tends to flow out of the spray jet stream into the surrounding atmosphere, which dilutes the stream, thereby reducing the temperature of the stream to such an extent that self-twisting of the oxidizing material ceases. As the formation ratio of refractory bodies decreases, low-quality refractory bodies are formed.

The spraying jet flow from the inner nozzle outlet has further significance.

The advantage is that the inner nozzle outlet is surrounded by peripheral nozzle outlets, allowing the inner nozzle outlet to have a larger diameter than other outlets, with virtually no risk of material spillage from the inner flow or dilution of the flow. As a result, it is possible to increase the spray amount ratio of granular material and form a high quality refractory body at a high rate. Therefore, in the embodiment of the present invention, the overall discharge rate from the inner nozzle outlet is set to be larger than the discharge rate from each peripheral nozzle outlet. The total cross-sectional area of the inner nozzle outlet is preferably 300 square meters or more, and in some cases, it is preferable that the total cross-sectional area of the inner nozzle outlet is 500 square meters or more, thereby reducing the rate of refractory discharge from the outlet. can be increased.

It is most convenient to use only one outlet from the inner nozzle, since this simplifies the feeding of the material to be discharged.

Most preferably, the cross-sectional area of each peripheral nozzle outlet is less than or equal to 320 square irises. When spraying a jet stream from a peripheral nozzle with such a restricted outlet size, the outward flow of particulate material from the peripheral stream and the dilution of the jet stream are suppressed, thus reducing the refractory formation reaction rate. is enhanced.

When using a peripheral nozzle with a limited outlet size as described above in combination with an inner nozzle having a relatively large diameter outlet,
The above advantages are particularly noticeable.

Regardless of the overall discharge rate of the material, when looking at the entire material discharged per unit time, there will be some material outflow and dilution of the peripheral jet stream, but the peripheral jet stream will be better compared to the larger inner jet stream. Since it is possible to form a screen with a high degree of stability, the proportion of the above-mentioned adverse effects is small.

Preferably, the granular mixture is sprayed from at least six nozzle outlets to increase the discharge rate of the sprayed material.

In an embodiment of the invention, at least six nozzle outlets for spraying the granular mixture are located at approximately equal radial distances and at approximately equal angular intervals with respect to the axis of the lance head. .

This can promote circular symmetry of the thermal spray jet flow in the axial rotation. Therefore, during thermal spraying, the lance is moved relative to the work surface, and material can be deposited on the work surface regardless of the orientation of the lance relative to the direction of movement.

As mentioned above, the present invention is also directed to a lance for spraying particles of exothermic oxidizing material and particles of refractory material in a flammable gas.

It is also an object of the present invention to provide a lance that can rapidly form high quality refractories.

Accordingly, the present invention provides a lance for thermal spraying granules of exothermic oxidizing material and granules of refractory material in a combustible gas, the lance having a head for discharging the granular material. The lance head includes a group of nozzles, and the spaced arrangement of the nozzle outlets is shown when the nozzle outlets of the group are viewed from the end side, and each nozzle outlet is connected to a first other nozzle of the group. away from the outlet by a distance not more than three times the minimum diameter of the cross-section of itself or said first other nozzle outlet, and with respect to the other nozzle outlets of 'lJ2 of said group, itself or said first other nozzle outlet. Nozzles that are spaced apart by a distance not more than 8 times the minimum diameter of the cross-section of the other nozzle outlets in the above group, such that the centers of the nozzle outlets of at least some of the above groups form the vertices of a virtual polygon. It provides:

An example of a lance head equipped with a nozzle group under the above-mentioned limiting conditions is shown in FIG.
It is described in Figure 2. The applicant does not claim any rights in this application to the tortoise-headed lance shown in those drawings.

The present invention also provides a lance for spraying granules of a heat-generating oxidizing material and granules of a refractory material in a combustible gas, the lance having a head for discharging the granular material. The lance head includes a group of nozzles, and the spaced arrangement of the nozzle outlets is shown when the nozzle outlets of the group are viewed from the end side, and each nozzle outlet is connected to a first other nozzle of the group. separated from the outlet by a distance not more than three times the minimum diameter of the cross-section of itself or the first other nozzle outlet, and with respect to the second other nozzle outlet of the group;
separated by a distance υ not more than 8 times the minimum diameter of the cross-section of itself or said second other nozzle outlet, such that the centers of the nozzle outlets of at least some of said group form vertices of an imaginary polygon. The present invention provides a lance characterized in that the lance is provided with at least three longitudinal feed passages leading to the head.

The multi-configuration lance of the present invention is particularly useful for intensively depositing refractory materials to increase volume fraction. By arranging a plurality of nozzles in the above groups in a special relationship, it is possible to rapidly form refractories of excellent quality and durability, provided that the discharge rates of the individual nozzles are suitable. If the feed paths are provided separately, the feed conditions in those paths can be controlled individually, which improves the feed distribution to each nozzle and also improves the feed distribution between multiple nozzles, subgroups, or individual nozzles in a nozzle group. The flow conditions at the nozzle can be controlled.

Under certain working conditions, the lance described above can form a refractory body of higher quality than conventionally known lances, and has a wider range of working applications than conventional lances.

It has been found that by using the lance according to the invention, the structure of the bath deposit layer can be made generally homogeneous even when thick deposit layers are formed by multiple movements of the lance relative to the work surface. In particular, the layering phenomenon hardly occurs in the refractory weld layer.

The above-mentioned lance can be used, for example, when performing the above-mentioned method. With the lance structure of the invention, the method of the invention can be carried out very easily. By configuring as described above, the interval between the nozzle outlets can be set so that the above method can be carried out and the effect can be obtained.

According to the present invention, in addition to the nozzles constituting the above group, a lance having one or more nozzles arranged in a manner other than the above may also be used. However, it is preferable that the nozzle group is composed of all the nozzles located within the lance, which further prevents multi-layer formation.

It is preferable that each of the plurality of thermal spray nozzles is provided with an independent feeding passage. With this embodiment of the invention, there is no need to provide distribution chambers to feed the individual nozzles, thus reducing the possibility of irregular flow to the nozzles. When using the above distribution chamber, the direction of flow changes rapidly in the chamber once or several times, so if the granules to be sprayed are highly abrasive, the high-speed granules will wear out the lance in a short period of time. .

Preferably, at least some of the feed passages are provided with means for independently adjusting the material flow rate. Using this embodiment, the average velocity of at least some of the jet streams from the nozzle exit can be independently controlled. As mentioned above, if the average gas exhaust velocity of each jet stream is set so that the difference is within 10 inches compared to the average gas exhaust velocity of the other jet streams of the plurality of jet streams, the formation of the refractory The ratio and its quality can be increased.

The arrangement state in which the nozzles in the above group are arranged at intervals is as follows when the nozzle outlet in the above group is viewed from the end side.
It is preferable to set the distance away from the first other nozzle outlet of the group by a distance not more than twice the minimum diameter of the cross section of itself or the first other nozzle outlet. This feature brings the nozzle exits closer together, thus concentrating the heat more on the surface being worked on and directing the jet stream from the nozzle exits closer to the surrounding air, e.g. when using the method of the invention. It is possible to further suppress dilution, and as a result, it is possible to obtain the advantage that the formation ratio of the refractory body is improved.

The arrangement state in which the nozzles in the above group are arranged at intervals is as follows when the nozzle outlet in the above group is viewed from the end side.
Preferably, it is spaced apart from other nozzle outlets of the group by a distance at least equal to the minimum diameter of the cross-section of itself or the respective other outlet. A major advantage of this feature of the invention is that the jets of material from the nozzles are less likely to interfere with each other as they fly towards the work surface. This further improves the oxidation reaction during thermal spraying and promotes the formation of a uniform, high-quality refractory.

Preferably, the nozzle group is provided with at least two rows of spaced apart nozzle outlets. Such a nozzle arrangement is very simple, and the lance can easily be constructed with a variety of different nozzle outlets to suit the spraying of different types of refractory granules.

In an embodiment of the present invention, the nozzle group includes at least one inner nozzle and a plurality of peripheral nozzles, the center of the outlet of the peripheral nozzle forms the vertex of the virtual polygon, and the outlet of the inner nozzle is located inside the above polygon. When this feature is adopted, the advantage is that the material can be thermally sprayed from the nozzle while the work surface is relatively intensely heated, especially when welding refractory materials with high melting points such as alumina, magnesia, and zirconia. be.

When working with the lance according to the embodiment of the present invention,
The material jet stream sprayed from the inner nozzle outlet is
Surrounded at least partially by a jet stream sprayed from a peripheral nozzle outlet. The presence of jet streams from suitably spaced peripheral nozzle outlets provides a screening effect, inhibiting the escape of particulates from the inner stream to the ambient atmosphere, and diluting the inner stream with the relatively cooler ambient air. It is known that it is possible to regulate Further, the peripheral flow portion is similarly protected by the inner flow, and particulate material is prevented from flowing out into the surrounding outside air or being diluted by the outside air.

The degree to which particulate material outflow into the surrounding air and dilution of the jet flow can be suppressed depends on the screen effect of the surrounding flow. It is preferable that the linear spacing between the outlets of adjacent peripheral nozzles is not more than three times the minimum diameter of any one of the adjacent peripheral nozzle outlets, since this can promote the screen effect.

In accordance with embodiments of the invention, the linear spacing between the outlet of each peripheral nozzle and the outlet of its closest inner nozzle is no more than three times the smallest diameter of one of those nozzle outlets.

By adopting this feature, the conditions for the oxidation reaction that takes place during the use of the lance can be controlled easily and in good conditions, and the working surface can be strongly heated to weld the highly refractory material, thereby increasing the rate of formation of the refractory material, and A refractory body of very high quality can be formed.

Preferably, the (total) area of the inner nozzle outlet is larger than the area of each peripheral nozzle outlet.

When this feature is adopted, the screen effect mentioned above,
It is possible to increase the discharge rate of the sprayed material by preventing material spillage from the material stream sprayed from the inner nozzle and dilution by the surrounding outside air, and at any maximum allowable discharge rate, the lance construction is extremely simple. can be converted into One of the factors that determines the maximum permissible discharge rate from a nozzle is its exit area; therefore, a single nozzle with a certain exit diameter, for example, four nozzles each with a diameter half the said exit diameter. Can be used in place of the nozzle. Therefore, for any permissible discharge rate, the number of nozzles incorporated in the lance can be significantly reduced and the construction simplified.

The (total) area of the inner nozzle outlet is preferably 300 square meters or more, and in some cases it is preferable that the area is 500 square meters or more, so that the ratio of the amount of discharge from the outlet can be increased.

Preferably, only one outlet of the inner nozzle is provided to simplify the lance structure.

Most preferably, the cross-sectional area of each peripheral nozzle outlet is less than or equal to 320 square inches. This limits the dimensions of the thermal spray jet stream and sets the dimensions to an extent that prevents particulate material from flowing outward from the surrounding stream and prevents dilution of the jet stream, thereby reducing the material spray rate from the lance. The formation rate of the refractory body can be increased. The above advantages are particularly pronounced when a peripheral nozzle with a limited outlet size as described above is used in combination with an inner nozzle having a relatively large diameter outlet. Regardless of the overall discharge rate of the material, a better screen can be formed with a peripheral jet stream versus a large inner jet stream.

Preferably, the granular mixture is sprayed from at least six nozzle outlets to increase the discharge rate of the sprayed material.

In an embodiment of the invention, at least six nozzle outlets of the lance are located at generally equal radial distances and at generally equal angular intervals relative to the axis of the lance head. This can promote circular symmetry of the thermal spray jet flow in the axial rotation. Therefore, during thermal spraying, the lance is moved relative to the work surface, and material can be deposited on the work surface regardless of the orientation of the lance relative to the direction of movement.

The present invention will now be described in detail with reference to the accompanying drawings.

In FIGS. 1 and 2, the lance shaft 1 is connected to the inner tube 20.
, an intermediate tube 3, and an outer tube 4 are provided concentrically. these tubes 2
, 3.4 each have one end expanded to form a part of the lance head 5. The inner tube 2 forms a feed channel 6 for supplying particulate material to the head 5 by means of a transport gas. The inner tube 2 and the intermediate tube 3 are held at intervals by a plurality of small-diameter feed tubes 7 for supplying auxiliary combustion oxygen to the head 5. The small-diameter feed pipe 7 can be welded to the inner pipe 2 and the intermediate pipe 3 via a web (not shown), if necessary, or the welded part (if a web is provided, the welded part and the web) can be continuous in the longitudinal direction of the shaft portion 1, or can be provided intermittently. The intermediate tube 3 and the outer tube 4 are held at a distance by a web 8 fixed therebetween by welding or the like.

As shown in FIG. 2, the end 9 of the small diameter feed tube 7 projects into the enlarged head 5 of the lance, and its outlet 10 opens into a mixing chamber 11. In use, the lance may contain granules of refractory material consisting of silica, alumina, zircon, zirconia, magnesia or a mixture of two or more of these substances, silicon, aluminum, zirconium, manesium or a mixture of two or more of these substances. Together with the particles of the exothermic oxidizing substance comprising the mixture, they are transported through the central feed passage 6 by air or oxygen-enriched air or a transport gas comprising oxygen, and auxiliary oxygen is supplied from each small-diameter feed pipe 7. Air alone is unlikely to support the explosion of oxidizing material in the mixture, especially considering the moderately low temperatures, so if air is used alone as the transport gas, it will not flash along the central feed passage 6. The risk of pack occurrence can be kept low. The expanded ends of the inner tube 2 and the outer tube 3 are connected by an annular closing member 12, and the expanded end of the intermediate tube 3 has its tip located in front of the closing member 12. Therefore, in order to maintain the temperature of the lance at a suitably low level, it is necessary to
It is also possible to circulate a coolant in the space between the outer tube 4 and the outer tube 4. For example, a counterflow type cooling jacket may be provided so that water flows between the inner tube 2 and the intermediate tube 3 toward the lance head, and between the intermediate tube 3 and the outer tube 4 toward the lance base.

Attach the plug member 13 (Figs. 2 and 3) to the screw 14 of the lance head 5.
Figure) is screwed into the nozzle group for thermal spraying.

The plug member 14 is formed with eight nozzles 15 arranged in an annular shape, and the center of the outlet of the nozzle 15 forms the apex of an octagon.

The outlets 10 of the small diameter feed tubes 7 are each directed to one nozzle 15, and each feed tube 7 is provided with a regulating valve as indicated by the reference numeral 16.

With this configuration, the discharge speed from each nozzle outlet can be independently controlled.

According to an example of a practical structure, the outlet diameter of each nozzle 15 is 2
The center of the reed is 65 meters away from the center O of the end face of the lance head 5. The distance between the centers of the nozzles is approximately 59.3
m, so the linear spacing S between adjacent nozzle outlet circumferences is approximately 30.3 m, and each nozzle outlet has a width of approximately 1.5 of its diameter with respect to two adjacent outlets. It's twice as far away.

The center portion of the plug member 13 is recessed outward), and the recess is filled with asbestos or other heat-resistant material 17 for heat insulation.

In each of FIGS. 4 and 5, the two ends of the lance are shown in longitudinal cross-section, and the center of each figure shows a cross-section of the lance shaft.

In these figures, each nozzle is connected separately to its own feed tube. When a feed pipe is attached to each nozzle, their centers coincide and the dimensions are the same, so the nozzle placement in front of the end of the lance head is easy from the cross section of the corresponding lance shaft. It can be inferred that The inner tube 2 of each lance shank forms a feed passage 6, which in each case terminates in an inner nozzle 18.

A plurality of small diameter feed pipes 7 (only six are shown) are connected to the inner nozzle 1.
It is continuous with an annular peripheral nozzle 15 surrounding the nozzle 8 .

The lance shaft of the embodiment shown in FIG. 4 is provided with an intermediate tube 3 and an outer tube 4 concentrically with the inner tube 2, as in the case of FIGS. 1 and 2, and these are for the lance shaft. forming a backflow cooling jacket. The head end of the outer tube 4 is closed by a closing plate 12 through which a nozzle 15.18 is inserted.
protrudes, and the end of the intermediate tube 3 is open at the head. At the proximal end of the lance shaft, the outer tube 4 is closed by a closing member 19 through which the proximal ends of the various tubes 2, 7 and the intermediate tube 3 project. Further, the intermediate tube 3 itself is closed by a closing member 20, through which the various tubes 2, 7 protrude.

A coolant outlet 21 is provided at the base end of the intermediate tube 3, and a coolant outlet 22 is provided at the base end of the outer tube 4. Therefore, the coolant such as water flows between the inner pipe 2 and the intermediate pipe 3 while contacting all the feed pipes 2 and 7, and then flows between the intermediate pipe 3 and the outer pipe 40.
circulate in reverse. The small diameter feed tube 7 is fixed at a predetermined position between the inner tube 2 and the outer tube 3 by a web 8.

As is clear from the cross section shown in the center of FIG. 4, the center of the outlet of the peripheral nozzle 15 forms a virtual polygon (in this case, a hexagon).

The cooling system shown in FIG. 5 is slightly different from that shown in FIG. In FIG. 5, the lance shaft outer tube 4 is shown, but the intermediate tube is not shown. As in the previous case, the head side end of the outer tube 4 is closed by the closing plate 12.
A nozzle 15.18 projects through the plate 12. Between the inner tube 2 and the outer tube 4, a plurality of open-ended tubes 24 are arranged alternately with respect to the small-diameter feed tube 7. At the proximal end of the lance shank, these tubes 24 open into a closed box 25 . The box 25 closes the proximal end of the outer tube 4, and
Also, various feed pipes 2, 7 protrude through the box 25.

The closed box 25 is provided with a coolant population 21, and after flowing through the pipe 24, the coolant flows back between the inner pipe 2 and the outer pipe 4 while contacting all the feed pipes 2 and 7, and flows through the outer pipe. The coolant is discharged from the coolant outlet 22 at the proximal end of the coolant. The small diameter feed tube 7 is fixed to the outer tube 4 by a short web 8, so that the coolant is circulated between the feed tube and the outer tube over a large part of their length to promote the cooling effect. There is.

In a specific embodiment of the lance manufactured according to FIGS. 4 and 5, the diameter of the central feed pipe 2 and the inner nozzle 18 is 3
0 m, and the diameters of the small diameter outer feed pipe 7 and nozzle 17 can each be 16 m. The centers of the peripheral nozzles 15 are separated from the centers of the inner nozzles 18 by 40+m, which distance is the same as the linear distance between the centers of the peripheral nozzles. The distance between their exits is therefore 24 cabinets. The outlet of the peripheral nozzle is 17 m away from the outlet of the inner nozzle. The various feed pipes are supplied with the same thermal spray mixture from a common source or from different sources. Preferably, a flow control regulator valve (not shown) is provided in the fluid passageway leading to each nozzle passageway 15.18. The valve may be integrated into the lance itself or may be provided as part of a device for supplying the material to be sprayed to the lance.

FIG. 6, jJ7 shows another embodiment of a lance having a shaft 1 and a head 5. In FIG. The lance is provided with a rectangular cross-section tube 26 including six feed tubes 27, which supply granular materials by air as a transport gas to six nozzles 28 arranged in two rows of three nozzles. There is. The nozzle 28 has a larger diameter than the feed pipes 27, and is adapted to receive a flow of supplementary combustion oxygen that is supplied separately. The auxiliary combustion oxygen is supplied from the central oxygen feed 2-in 29 via the manifold 30 to the nozzle 28 at the head of the lance. The lance shaft tube 26 has plates 31 and 32 at its head end and proximal end, respectively.
The tube 26 is also provided with a pair of open end tubes 33. A coolant such as water is fed into the lance through the pipe 33 and circulates in the lance in the opposite direction while contacting the feed pipe 27 and returns to the outlet pipe 34. Preferably, a flow control regulator valve (not shown) is provided in the fluid path leading to each nozzle 28 to individually adjust the nozzle exit velocity of each nozzle. The valve may be integrated into the lance itself or may be provided as part of a device for supplying the material to be sprayed to the lance.

Figure 8 is a schematic end view of the lance head, with nozzles 2 at the four corners.
The exit centers of 8 form a virtual polygon (a quadrilateral in this case). Since each row of nozzles is straight, the exit center of the central nozzle 28 of each row is located on opposite sides of the quadrilateral. In a specific visit, nozzle 2
The outlet diameter of all No. 8 is 13 m. The outlets of the three nozzles in each row are separated by a distance S1 of 17 m, and the outlets of the two rows are separated by a distance B2 of 47 m.

! In a modification of the embodiment shown in FIGS. 1a-8, the feed tubes 27 can each have the same diameter as the nozzles 28, and the oxygen feed twin 29 and manifold 30 can be eliminated.

In use, the lance according to the invention is supplied with a suitable mixture of particulate material by means of a combustible transport gas. As with known methods, the delivery rate of the transport gas has a significant influence on the working results, and such delivery rate can be easily selected by a person skilled in the art based on known criteria. In short, oxygen must be supplied at a higher rate (for example, twice) than the theoretically required value.

Various examples of the invention are described below.

Example 1 A plurality of cracks of approximately the same size and shape were formed in a furnace wall formed of silica blocks, primarily in the form of tridymite. These cracks were repaired by spraying the starting mixture at a furnace wall temperature of 1150°C. The above mixture is
It was composed of 87 inches of silica, 12 qb of silicon, and 1 inch of aluminum in a weight ratio, and was connected to six nozzle outlets as shown in Figure 8 at a rate of 360 to 4/hour using oxygen as a transport gas. The placed lance was sprayed. The silica used was composed of cristobalite and tridymite in a weight ratio of 3=2, and the particle size was 100μ.
m and 2. The average particle diameters of the silicon and aluminum particles are each less than 10 μm.

The specific surface area of silicon is 4000 cd/l, and the specific surface area of aluminum is 6000 cd/f'. In all cases, all nozzles were circular and female, with an exit diameter of 125 wg. Therefore, the total nozzle exit area is 6.
78, the material discharge rate is 53 Kf per hour for a total nozzle exit area of 1 square α.

Each of the above cracks was repaired using various lances. The specific relationship between the nozzle outlets of the five lances A-11i is as shown in Table I below. Table 3 shows the amount of granular material needed to repair by welding approximately the same amount of refractory material, as well as the result (repair quality).

Table I Spacing in each column Spacing between columns Emission amount Result B1w
x B2ws K? A 18
48 8 No layering B 18
84 8.5 No perceptible stratification 0* 18 100* 9 Weak stratification D* 40* 84 9 Occasional stratification x* 50” 100* 1
0 Significant stratification This invention is not based on this invention.

As is clear from the above examples, the work according to the invention makes it possible to form refractories of high quality (as evidenced by the absence of layering phenomena) and, moreover, with respect to the dimensions of the cracks to be repaired. This has the advantage that the above results can be achieved with a smaller amount of emissions required.

Example 2 An electroformed C!orhart Zac (trademark) block (composed of zirconia, alumina, and silica) was sprayed with a starting mixture to form a uniform layer of refractory material of the same thickness. The temperature of the coated block in that case was approximately 1200°C.

The composition of the mixture used was 35 parts zirconia and 53 parts alumina, as well as additives of silicon and alumina, in a weight ratio of 8 parts silicon and 4 parts aluminum. The starting mixture was sprayed at various rates depending on the lance used and oxygen was used as the transport gas.

The particle sizes of the alumina and zirconia granules are 50 μm to 500 μm), and the silicon and aluminum particle sizes are the same as in Example 1, respectively.

Various lances were constructed based on FIG.

In Table 1 below, 115 indicates the outlet diameter of each of the six peripheral nozzles 15, and FIJ18 indicates the outlet diameter of the inner nozzle 18. 815 is the adjacent peripheral nozzle 1
Compare with the interval day in Figure 3 showing the interval between the exits of 5)
315-18 indicates the spacing between the outlet of each peripheral nozzle 15 and inner nozzle 18.

Table ■ e 15 a 18 S 15 S 15-18 Emission rate Usage Result 16 16 24 24
53.3 35 Excellent 16 30
24 17 52.3 40 Excellent 1
6 16 48 48 52.3 38
Satisfied 16 30 65 58* 52.3
50 Layering* *Not based on the present invention.

Diameter 16! The agglomeration rate of the granules discharged from the lance with an internal nozzle outlet of I+ is 750 Kr/h, diameter 3C
) 1000 for a lance with an internal nozzle outlet of s
Kf/hour.

As is further evident from this example, the operation according to the invention makes it possible to form a refractory body of high quality while saving the required output of material, regardless of the amount of refractory body to be welded.

[Brief explanation of drawings]

Figure 1 shows the lance shaft corresponding to the I-1 section in Figure 2.
A cross-sectional view of the i41 embodiment; FIG. 2 is a sectional view showing the lance shaft section taken along the line ■-■ in FIG. 1 and the end of the lance head; FIG. 4 and 5 are partially cutaway cross-sectional schematic diagrams showing two other embodiments of the present invention, and WIG and FIG. 7 are lances of yet another fourth embodiment of the present invention. End front view and cross-sectional view, No. 8
The figure is a schematic end view corresponding to FIG. 6. 1--Lance, 5--Lance head, 6--Feeding) passage, 15-m-Peripheral nozzle, 18--One inner nozzle

Claims (1)

[Claims] 1. A method for forming a refractory on a work surface by spraying a mixture of exothermic oxidizing particles and refractory particles onto a work surface in a flammable gas, the method comprising: The material to be thermally sprayed is transported to the head of the lance along the line and the mixture is discharged, and the conditions at the time of discharge are such that the oxidizing particles react with the flammable gas to generate heat, and the thermal spraying is caused by the heat. In a method set such that at least the surface of the refractory granules is melted to form the refractory body, a mixture of oxidizing granules and refractory granules is thermally sprayed in a flammable gas from a group of nozzle outlets; The discharge rate during thermal spraying is set to 1 per square cm of total nozzle exit area.
50 Kg per hour, and the spaced arrangement of the nozzle outlets of the group is such that, when viewed from the end side, each nozzle outlet is relative to the first other nozzle outlet of the group. separated by a distance not more than three times the minimum diameter of the cross section of itself or the first other nozzle outlet, and the second of the group
with respect to other nozzle outlets of said group by a distance not more than eight times the minimum diameter of the cross-section of itself or said second other nozzle outlets, such that the center of said nozzle outlets of at least some of said group is A method for forming a refractory body, characterized in that settings are made to form vertices of a virtual polygon. 2. The refractory forming method according to claim 1, wherein the nozzle group is composed of all nozzles located within a lance. 3. The average gas discharge rate from each nozzle in the above group is 10% compared to the average gas discharge rate from each other nozzle in the above group.
3. The method for forming a refractory body according to claim 1 or 2, wherein the difference is within a range of less than 100%. 4. When viewing the nozzle outlets of the group from the end side, the spaced arrangement of the nozzles of the group is such that each nozzle outlet of the group has its own position with respect to the first other nozzle outlet. or the refractory molding according to any one of claims 1 to 3, wherein the refractory molding is set to be separated by a distance that is equal to or less than twice the minimum diameter of the cross section of the first other nozzle outlet. Method. 5. The spaced arrangement of the nozzles in the group is such that when the nozzle outlets in the group are viewed from the end side, each nozzle outlet in the group has no relation to itself or to the other nozzle outlets in the group. 5. The refractory forming method according to claim 1, wherein the refractory forming method is set to be separated by a distance at least equal to the minimum diameter of the cross section of each other outlet. 6. The granular mixture is thermally sprayed from the nozzle group comprising at least two rows of nozzle outlets spaced apart from each other. The refractory forming method described. 7. The nozzle group includes at least one inner nozzle and a plurality of peripheral nozzles, and the center of the outlet of the peripheral nozzle forms the apex of the virtual polygon, and the outlet of the inner nozzle is located at the center of the polygon. 7. The method for forming a refractory body according to claim 1, wherein the refractory body is positioned on the inside. 8. The method for forming a refractory body according to claim 7, wherein the linear interval between the outlets of adjacent peripheral nozzles is set to three times or less the minimum diameter of one of the adjacent peripheral nozzle outlets. 9. Claim 7 or 9, characterized in that the linear distance between the outlet of each peripheral nozzle and the outlet of the inner nozzle closest thereto is not more than three times the minimum diameter of one of those nozzle outlets. The method for forming a refractory body according to item 8. 10. The refractory forming method according to any one of claims 7 to 9, characterized in that the overall discharge rate from the inner nozzle outlet is greater than the discharge rate from each peripheral nozzle outlet. 11. The total cross-sectional area of the inner nozzle outlet is 300 square meters.
The refractory forming method according to any one of claims 7 to 10, characterized in that the refractory forming method is made to be at least m. 12. The total cross-sectional area of the inner nozzle outlet is 500 square meters.
12. The method for forming a refractory body according to claim 11, wherein the refractory forming method is made to be at least m. 13. The refractory forming method according to any one of claims 7 to 12, wherein the number of the inner nozzle outlet is one. 14. The cross-sectional area of each peripheral nozzle outlet is 320 square mm.
A refractory forming method according to any one of claims 7 to 13, characterized in that: 15. The refractory forming method according to any one of claims 1 to 14, characterized in that the granular mixture is thermally sprayed from at least six nozzle outlets. 16. A patent characterized in that at least six nozzle outlets for thermally spraying the granular mixture are located at approximately equal radial distances and at approximately equal angular intervals with respect to the axis of the lance head. A refractory forming method according to claim 15. 17. Contents of the disclaimer: A lance for spraying granules of exothermic oxidizing material and granules of refractory material in flammable gas, the lance having a head for discharging the granular material. , the lance head is provided with a group of nozzles, and the nozzle outlets are arranged at intervals, when the nozzle outlets of the group are viewed from the end side, each nozzle outlet is
separated from the first other nozzle outlet of said group by a distance not more than three times the minimum diameter of the cross-section of itself or of said first other nozzle outlet; , the center of at least some of the nozzle outlets of said group is a vertex of an imaginary polygon. Lance set to form. 18. A lance for spraying granules of exothermic oxidizing material and granules of refractory material in a combustible gas, the lance having a head for discharging the granular material, the lance head is provided with a group of nozzles, and the spaced arrangement of the nozzle outlets is such that, when the nozzle outlets of the group are viewed from the end side, each nozzle outlet is relative to a first other nozzle outlet of the group. a distance not more than three times the minimum diameter of the cross-section of itself or said first other nozzle outlet, and with respect to a second other nozzle outlet of said group; 8 of the minimum diameter of the cross-section of the nozzle outlet of
the nozzle exit centers of at least some of said groups form vertices of a virtual polygon, and said lance has at least three longitudinal directions extending to said head; A lance characterized by having a feeding passage. 19. The lance according to claim 17 or 18, wherein the nozzle group is composed of all nozzles located within the lance. 20. The lance according to any one of claims 17 to 19, wherein each of the plurality of thermal spray nozzles is provided with an independent feeding passage. 21. A lance according to claim 20, characterized in that at least some of the feed passages are provided with means for independently adjusting the material flow rate. 22. The spaced apart arrangement of the nozzles in the group is such that when the nozzle outlets in the group are viewed from the end side, each nozzle outlet in the group is self-contained with respect to the first other nozzle outlet. The lance according to any one of claims 17 to 21, characterized in that the lance is set to be separated by a distance that is equal to or less than twice the minimum diameter of the cross section of the first other nozzle outlet. 23. The spaced arrangement of the nozzles in the group is such that when the nozzle outlets in the group are viewed from the end side, each nozzle outlet in the group has no relation to itself or to the other nozzle outlets in the group. 23. A lance according to any one of claims 17 to 22, characterized in that the lances are spaced apart by a distance at least equal to the minimum diameter of the cross-section of each other outlet. 24. Claim 1, wherein the nozzle group includes at least two rows of spaced apart nozzles.
The lance according to any one of Items 7 to 23. 25. The nozzle group includes at least one inner nozzle and a plurality of peripheral nozzles, and the center of the outlet of the peripheral nozzle forms a vertex of a virtual polygon, and the outlet of the inner nozzle is located inside the polygon. The lance according to any one of claims 17 to 23, characterized in that the lance is located at. 26. The lance according to claim 25, wherein the linear spacing between the outlets of adjacent peripheral nozzles is not more than three times the minimum diameter of one of the adjacent peripheral nozzle outlets. 27. Claim 25 or 26, characterized in that the linear distance between the outlet of the peripheral nozzle and the outlet of the inner nozzle closest thereto is not more than three times the minimum diameter of one of those nozzle outlets. The lance described in Section. 28. The lance according to any one of claims 25 to 27, wherein the total area of the inner nozzle outlet is larger than the area of each peripheral nozzle outlet. 29. The lance according to any one of claims 25 to 28, characterized in that the total area of the inner nozzle outlet is 300 square mm or more. 30. The lance according to claim 29, wherein the total area of the inner nozzle outlet is 500 square mm or more. 31. The lance according to any one of claims 25 to 30, characterized in that the number of the inner nozzle outlet is one. 32. The cross-sectional area of each peripheral nozzle outlet is 320 square mm.
The lance according to any one of claims 25 to 31, characterized in that: 33. The lance according to any one of claims 17 to 32, characterized in that the lance is provided with at least six nozzles. 34. The lance is provided with at least six nozzles located at approximately equal radial distances and at approximately equal angular intervals with respect to the axis of the lance head. The lance described in item 33.