JP2007238977A - Thermal spraying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal spraying device capable of preventing any complicated or expensive configuration thereof and preventing any increase in the operational cost by preventing backfire to the hopper of a raw powder. <P>SOLUTION: In the thermal spraying device, a raw powder is mixed with a combustion-supporting carrier gas to form a mixture, and the mixture is ejected and subjected to the combustion to form a refractory composition. The thermal spraying device comprises a hopper having a delivery port for storing and delivering the raw powder at a bottom part, an ejector for sucking the raw powder from the delivery port by the flow of the pressurized carrier gas, and mixing the carrier gas with the raw powder to form the mixture, and a spraying means for spraying the mixture generated by the ejector; and further comprises an outside air communication unit to be communicated with the outside air provided to a raw material powder transfer passage for transferring the raw material powder from the delivery port to the ejector. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal spraying apparatus, and more particularly, a raw material powder containing a combustible powder (for example, a metal powder) and a refractory powder (a refractory aggregate powder). The present invention relates to a thermal spraying apparatus that is used for thermal spraying work that forms a refractory composition (usually layered) by being transported by gas, injected, and melted by ignition.

  Raw material powder containing combustible powder (for example, metal powder) and fire-resistant powder (fire-resistant aggregate powder) is conveyed and injected by a combustion-supporting carrier gas (for example, oxygen gas). The refractory powder is heated and melted (or melted) using combustion energy generated by burning the mixture of the injected raw material powder and carrier gas (mainly combustible powder and carrier gas are combusted). Thermal spraying that forms a coating layer (refractory composition) by spraying on the object to be coated has been widely used so far (for example, Patent Document 1 and Patent Document 2).

  For example, Patent Document 1 states that “when a powder containing a combustible powder is sprayed onto a covering using a support gas, a backfire at the nozzle tip or a combustibility in a powder feeder. It was made in order to prevent ignition of powder reliably (paragraph number 0008 in the detailed description of the invention of Patent Document 1). Powder supply method for refractory spraying in which mixed powder is transported in a conduit using a combustion-supporting carrier gas and sprayed from a discharge nozzle onto a work surface or mold to form an ignited / molten refractory layer In the present invention, a powder feeder for storing the supplied mixed powder is provided at the front position of the discharge nozzle, and the inside of the feeder is sealed with an inert gas to hold the pressure ”(invention of Patent Document 1) In the detailed description, paragraph number 0009) device etc. are disclosed That.

  Patent Document 2 states that “a thermal spray repairing material that melts and repairs a refractory powder by burning metallic silicon, and the metallic silicon can be stably supplied and attached without reducing fluidity, Thermal spray repair characterized in that the required amount of particle size that does not cause flashback is mixed with the required amount of coke material of particle size that contributes to the ignitability and flame stability of the metal silicon and maintains fluidity. It is disclosed that no flashback is caused by using “material” (paragraph number 0016 in the detailed description of the invention of Patent Document 2).

JP-A-8-109461 (for example, paragraph numbers 0001 to 0004, 0013 to 0014, FIG. 1 and the like in the detailed description of the invention) JP-A-9-132470 (for example, paragraph numbers 0001 to 0016 in the detailed description of the invention)

  As described above, such thermal spraying is performed by conveying and injecting a raw material powder containing a combustible powder and a refractory powder with a carrier-supporting carrier gas, and the injected raw material powder and carrier gas. The combustion of the mixture (mainly the combustible powder and the carrier gas are combusted), the flame of the mixture being injected and combusted causes the raw material powder and the carrier gas to flow. There has been a problem (so-called “backfire”) that it moves in the direction opposite to the direction in which it reaches and reaches the hopper that stores the raw material powder. In such a case, a fire or explosion may occur in the hopper of the raw material powder, which has been a major problem in thermal spraying.

  In order to solve the backfire of the raw material powder to the hopper, various investigations have been made in a thermal spraying apparatus and the like. For example, in Patent Document 1, a powder feeder for storing the supplied mixed powder is provided at a position in front of the discharge nozzle, and the inside of the feeder is sealed with an inert gas to hold the pressure. However, this requires a powder feeder that is sealed and maintained with an inert gas, and thus the thermal spraying apparatus is complicated and expensive, and the use of the inert gas increases operating costs. There was a problem of increasing.

  Therefore, in the present invention, in order to prevent backfire of the raw material powder to the hopper, a thermal spraying device is provided in which the configuration of the thermal spraying device does not become complicated or expensive, and the operating cost does not increase. The purpose is to do.

  The thermal spraying apparatus of the present invention (hereinafter referred to as “the present apparatus”) mixes a raw material powder containing a combustible powder and a refractory powder and a combustion-supporting carrier gas into a mixture, A thermal spraying apparatus for injecting and combusting a mixture to form a refractory composition, the hopper having a discharge outlet at the bottom for storing the raw material powder and discharging the raw material powder, and the pressurized carrier gas An ejector for sucking the raw material powder from the discharge outlet by flow and mixing the carrier gas and the raw material powder into the mixture; and an injection means for injecting the mixture generated by the ejector. A thermal spraying apparatus in which a raw material powder transfer path for transferring the raw material powder from the discharge port to the ejector is provided with an outside air communication portion communicating with the outside air.

This apparatus, like the conventional thermal spraying apparatus, injects and burns a mixture of raw material powder (including combustible powder and refractory powder) and a flammable carrier gas, and burns it. In general, the combustible powder in the raw material powder is combusted by the combustion-supporting carrier gas, and the refractory powder in the raw material powder is dissolved (melted) by the heat generated by the combustion. Or it forms a refractory composition by becoming a state close | similar to it.
And this apparatus is provided with a hopper, an ejector, and an injection means. The hopper has a discharge outlet at the bottom (below the stored raw material powder) for storing the raw material powder and discharging the raw material powder. In the ejector, when the pressurized carrier gas is injected inside the ejector, the inside of the ejector becomes a negative pressure (pressure lower than the pressure of the surrounding environment (usually atmospheric pressure)), and this causes the hopper discharge port Inhalation of raw material powder. The ejector mixes the sucked raw material powder and the injected carrier gas inside the ejector to obtain the mixture. Then, the mixture of the raw material powder and the carrier gas is sent from the ejector to the injection means and is injected by the injection means. The jetted mixture burns, and the refractory powder is dissolved (melted) or close to the heat-resistant powder to form a refractory composition.
In this device, the raw material powder transfer path for transferring the raw material powder from the hopper outlet to the ejector is provided with an outside air communication portion communicating with the outside air, and even if a backfire occurs from the injection means to the ejector, It is possible to prevent or reduce the backfire from reaching the hopper that stores the raw material powder by dissipating the backfire from the outside air communication portion.

The outside air communication part may be configured by a pipe having one end communicating with the outside air and the other end communicating with the raw material powder transfer path.
In this way, an outside air communication portion communicating with the outside air can be easily provided in the raw material powder transfer path, and the one end communicating with the outside air (backfire is dissipated) is taken from the hopper for storing the raw material powder. It can be easily separated and the influence on the hopper due to flashback can be reduced.

The ratio (S1 / S2) of the channel cross-sectional area S1 of the outside air communication portion to the channel cross-sectional area S2 of the raw material powder transfer path may be 0.05 or more and 1.0 or less (hereinafter, “ Predetermined cross-sectional area ratio apparatus ”.
Note that both the cross-section of the raw material powder transfer path and the cross-section of the outside air communication section have a direction in which fluid flows at each position (in the case of the cross-section of the raw material powder transfer path, the raw material powder is hopper In the case of the cross section of the flow path of the outside air communication portion, it is the direction in which fluid such as air moves between the outside air and the raw material powder transfer path. A cross section of a simple flow path. Further, in both of the cross section of the raw material powder transfer path and the flow path cross section of the outside air communication portion, when the area of the cross section of the flow path varies depending on the position of the flow path, the minimum areas are set as S2 and S1, and the ratio (S1 / S2) is calculated.
If the ratio (S1 / S2) is too small, backfire cannot be sufficiently dissipated from the outside air communication part. Conversely, if it is too large, the raw material powder flows out from the outside air communication part or a large amount of air from the outside air communication part. Therefore, it is preferable to satisfy both of these conditions. Usually, it is 0.05 or more, preferably 0.1 or more, and most preferably 0.2 or more. Or less, preferably 0.7 or less, most preferably 0.6 or less (thus usually 0.05 to 1.0, preferably 0.1 to 0.7, most preferably 0.2 to 0). .6)).

Predetermined cross-sectional area ratio In the case of this apparatus, the flow passage cross section of the outside air communication portion may be a substantially circular shape having a diameter of 10 mm to 50 mm.
In addition, when the area of the channel cross section differs depending on the position of the channel, the channel cross section of the outside air communication portion refers to the channel cross section at the position where the area is the minimum.
The cross section of the flow path of the outside air communication part can dissipate backfire well from the outside air communication part, and prevents raw powder from flowing out from the outside air communication part and inhaling too much air from the outside air communication part. Any shape and size (dimension) may be used, for example, and the cross-sectional shape may be a circle, an ellipse, a sector, an n-gon (where n is a natural number of 3 or more), and the like. However, normally, if the cross section of the flow path of the outside air communication portion is made into a substantially circular shape with a diameter of 10 mm to 50 mm, the backfire can be dissipated well from the outside air communication portion and the outflow of the raw material powder from the outside air communication portion or Of large amounts of air can be prevented or reduced.

It is provided with a baffle member disposed inside the hopper so as to exist in at least a part of the projection area of the discharge outlet in a direction parallel to the payout direction (hereinafter referred to as “baffle member disposition main device”). May be.
“Discharge direction” refers to the flow direction of the raw material powder at the discharge port when the raw material powder is discharged from the discharge port of the hopper toward the raw material powder transfer path. The “direction parallel to the payout direction” refers to the direction of a straight line parallel to such a payout direction (therefore, one direction in which the straight line extends and another direction opposite to the one direction, There are two directions.) The projected area of the payout opening in a direction parallel to the payout direction (the projected area is formed by a straight column body having the payout opening as a bottom surface and a generatrix along the direction parallel to the payout direction). Of these, the area of the hopper inside is subjected to a large amount of backfire jet power when backfired inside the hopper via the discharge outlet, so that the raw material powder existing in the area inside the hopper is blown out of the hopper and scattered, etc. Problems can arise. For this reason, if a baffle member is provided inside the hopper so as to exist in at least a part of the projection area of the payout outlet in a direction parallel to the payout direction, the flashback when the backfire is caused inside the hopper via the payout opening When the baffle member receives the jet power, the jet power of backfire to the raw material powder existing in the region inside the hopper can be reduced, and the above problem can be prevented or reduced.

In the case of this apparatus having a baffle member, the horizontal cross-sectional area is a downwardly enlarged portion that monotonously increases from the top to the bottom, and an arbitrary horizontal cross-section that is an arbitrary cross-section in the horizontal direction is changed from the arbitrary horizontal cross-section. In addition, the baffle member may have a lower enlarged portion which is present in any horizontal cross section even if projected onto any horizontal cross section located below.
The baffle member disposed inside the hopper is such that it does not prevent the raw material powder stored inside the hopper from being discharged from the discharge port, and the reverse when the back hopper is backfired through the discharge port. It is preferable that the fire jet power can be effectively shielded from the raw material powder, and for this purpose, it should be as large as possible near the discharge outlet (the reverse fire jet power is effectively reduced from the raw powder). And when the raw material powder moves from above to below (there is a discharge outlet), the raw material powder is not caught or accumulated (the raw material powder is smoothly discharged from the discharge outlet). May be. In order to obtain such a shape, the baffle member may have a lower enlarged portion. The lower enlarged portion is any horizontal cross section in which the horizontal cross-sectional area monotonously increases from the upper side to the lower side, and an arbitrary horizontal cross section that is an arbitrary cross section in the horizontal direction is positioned below the arbitrary horizontal cross section. Since it is present in any horizontal cross section even if projected to the bottom, it is large below the discharge outlet (which effectively blocks the backfire jet power from the raw material powder) and any vertical plane. Since there is no recess in the cross-sectional shape of the material powder, the raw material powder is not caught or stored when moving from the upper side to the lower side (where the discharge port exists). To pay). If the entire baffle member is a lower enlarged portion (if the baffle member is composed only of the lower enlarged portion), it is less likely to prevent the raw material powder from being discharged from the discharge outlet, and the discharge outlet. Thus, it is possible to effectively block the backfire jet power from the raw material powder when backfired inside the hopper.

In the case of this apparatus, the baffle member is attached to the hopper by a mounting member arranged inside the hopper, which is constituted by a plate-like member arranged so that its main surface is substantially along the vertical direction. (Hereinafter referred to as “attachment member main device”).
The baffle member placed inside the hopper needs to be supported with sufficient strength so that it can catch the backfire jet output when backfired inside the hopper via the discharge outlet. Therefore, it is usually attached to the hopper by some means. Any means may be used as the means, and it is not limited at all. For example, the hopper and the baffle member are connected to each other by a member (for example, a rod-like member or a plate-like member), and the baffle member is connected to the hopper. Install. If the baffle member is attached to the hopper by a mounting member that is constituted by a plate-like member that is disposed so that the main surface thereof is substantially along the vertical direction, the baffle member with respect to the hopper As well as mounting the plate, the plate-shaped member constituting the mounting member (the main surface is substantially along the vertical direction) can successfully guide the raw material powder stored inside the hopper to the lower side where the discharge outlet exists. (The plate-shaped member constituting the mounting member serves as a guide plate for the raw material powder), and effectively prevents or reduces the fact that the raw material powders are pressed together and not discharged (so-called shelf-hanging phenomenon). be able to.
In addition, “the main surface is substantially along the vertical direction” means that an angle (referred to as an inferior angle) formed by a plane along the main surface of the plate-like member and a vertical surface is approximately 0 degrees. Preferably it is 15 degrees or less, more preferably 10 degrees or less, and most preferably 5 degrees or less (of course, 0 degrees or more).

Attachment member In the case of this apparatus, the attachment member may comprise a first plate-like member and a second plate-like member whose main surfaces intersect each other.
Thus, by setting it as the attachment member containing the 1st plate-like member and the 2nd plate-like member which a mutual main surface crosses, by the plate-like member (a main surface follows a substantially vertical direction) which constitutes an attachment member, The raw material powder stored inside the hopper can be guided well below the outlet and effectively prevents or reduces the fact that the raw material powders are pressed together and not discharged (so-called shelving phenomenon). be able to.
The angle at which the main surfaces of the first plate-like member and the second plate-like member intersect (referred to as an inferior angle) is preferably close to 90 degrees, usually preferably 75 degrees or more, more preferably 80 degrees. As mentioned above, it is most preferably 85 degrees or more (of course, 90 degrees or less).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited by these.

FIG. 1 is a schematic view showing an embodiment of a thermal spraying device (present device) 11 of the present invention. The apparatus 11 will be described with reference to FIG.
In general, the apparatus 11 includes an oxygen supply unit 21, an emergency stop unit 31 that shuts off oxygen supply from the oxygen supply unit 21 in an emergency, a hopper unit 41 that stores the raw material powder 91, an ejector 61, The transfer pipe 53 disposed between the hopper 41 and the ejector 61, the communication pipe 51 with one end communicating with the transfer pipe 53, and the oxygen that has passed through the emergency stop section 31 from the oxygen supply section 21 are directed toward the ejector 61. A check valve 39 that allows flow only to the hose, a hose portion 71 (flexibility) for flowing a mixture containing oxygen from the ejector 61 and the raw material powder 91, and a lance that receives and injects the mixture from the hose portion 71. Part 81.

The oxygen supply unit 21 includes an oxygen cylinder 23 filled with pressurized oxygen gas, a pressure adjustment valve 25 that adjusts the pressure of the oxygen gas from the oxygen cylinder 23, and a flow rate of oxygen gas that flows out from the pressure adjustment valve 25. And a flow rate adjusting valve 29 for adjusting the flow rate of oxygen gas. Using such an oxygen supply unit 21, the pressure adjustment valve 25 and the flow rate adjustment valve 29 can be adjusted to supply oxygen gas having a desired pressure and a desired flow rate to the emergency stop unit 31. Here, the pressure of the oxygen gas was 0.5 MPaG (gauge pressure), and the flow rate was 25 Nm ³ / h.

The emergency stop unit 31 includes an emergency cutoff valve 33 and an emergency stop switch 35 that operates the emergency cutoff valve 33. By operating the emergency stop switch 35, the emergency shutoff valve 33 can be fully closed (shut off) or fully opened.
Oxygen gas having a desired pressure and a desired flow rate supplied by the oxygen supply unit 21 flows into the check valve 39 after passing through the emergency shut-off valve 33, and the check is performed by operating the emergency stop switch 35. The supply of oxygen gas to the valve 39 can be interrupted (for example, when the device 11 is in an emergency state, the oxygen gas is supplied to the check valve 39 by operating the emergency stop switch 35. When the emergency state is released, the emergency stop switch 35 can be operated to restart the supply of oxygen gas to the check valve 39).

The oxygen gas that has passed through the emergency shut-off valve 33 of the emergency stop unit 31 flows into the check valve 39. The check valve 39 allows flow from the emergency shut-off valve 33 toward the ejector 61, but prohibits flow from the ejector 61 toward the emergency shut-off valve 33.
The oxygen gas that has passed through the check valve 39 flows into the ejector 61.

  In the internal space 65 of the ejector 61, oxygen gas is ejected at a high speed from the tip of the tapered nozzle 63 toward the outlet 67, thereby making the internal space 65 a negative pressure (here, a pressure lower than the atmospheric pressure). On the other hand, one end (lower end) of the transfer pipe 53 communicates with the internal space 65 (the transfer pipe 53 is a hollow cylindrical pipe disposed so as to face in a substantially vertical direction. Here, the lower end is the internal space. 65.)

The other end (here, the upper end) of the transfer pipe 53 communicates with a discharge outlet 43 formed at the bottom of the hopper 41. Furthermore, one end of the communication pipe 51 communicates between the one end (lower end) of the transfer pipe 53 and the other end (upper end). The other end of the communication pipe 51 (the end opposite to the one end) is open to the outside air.
The hopper portion 41 will be described in detail later, but combustible powder (specifically, silicon that is a metal powder here) and refractory powder (specifically, here is silica stone that is a powder of refractory aggregate). The raw material powder 91 that is generally commercially available for coke oven repair is stored, and the raw material powder 91 is discharged to the transfer pipe 53 through a discharge port 43 formed at the bottom of the hopper 41. It comes out.

  Since the internal space 65 of the ejector 61 is set to a negative pressure as described above, the raw material powder 91 of the hopper portion 41 from the discharge outlet 43 and the ambient atmosphere (here, air) from the communication pipe 51 are generated. The air is sucked into the internal space 65 of the ejector 61 through the transfer pipe 53. Then, in the internal space 65 of the ejector 61, the raw material powder 91 and the surrounding atmosphere (air in this case) are mixed with oxygen gas ejected from the tip of the nozzle 63, and the mixture is discharged from the outlet 67 and hose. The lance part 81 is reached via the part 71.

  The lance part 81 has a pipe part 83 with one end 83a connected to the terminal part of the hose part 71 and the other end 83b closed, and a nozzle part 85 connected in the vicinity of the other end 83b of the pipe part 83. Become. The mixture (a mixture of the raw material powder 91, the surrounding atmosphere (air), and oxygen gas) enters the one end 83a of the pipe portion 83 of the lance portion 81 through the hose portion 71, and then the pipe portion 83 is connected to the other end. It flows in the 83b direction and is sprayed from the nozzle portion 85 onto the refractory wall surface 98 (the wall surface temperature is usually heated to about 600 ° C. to 1000 ° C.). The injected mixture is ignited and combusted by coming into contact with the high-temperature refractory wall surface 98, and the refractory powder is dissolved (melted) or close to it by the heat generated by the combustion. Z).

Next, the hopper portion 41 will be described in detail. FIG. 2 is a diagram showing the hopper portion 41. Specifically, FIG. 2A is a plan view of the hopper portion 41 (shown from the direction of arrow Y in FIG. 1), and FIG. 2B is a front view of the hopper portion 41. (In FIG. 2 (a), it is seen from the direction of arrow C). 3A is a cross-sectional view showing only the mounting plate 47 and the baffle 49 in the AA cross section of FIG. 2A, and FIG. 3B is a cross-sectional view taken along the line B-B of FIG. It is sectional drawing which shows only the attachment board 47 and the baffle part 49 among the cross sections. With reference to FIG.2 and FIG.3, the hopper part 41 is demonstrated. In addition, the place which removed the raw material powder 91 from the inside of the hopper part 41 is shown here.
The hopper portion 41 roughly includes a hopper 45 that forms an outer portion of the hopper portion 41, a mounting plate 47 (attached to the inner surface of the hopper 45) disposed inside the hopper 45, and a mounting plate. And baffle portions 49 attached to the hopper 45 by 47.

  Here, the hopper 45 rotates about a straight line 42 extending in a substantially vertical direction (see FIG. 2, in which a vertical upward direction is indicated by an arrow D 1 and a vertical downward direction is indicated by an arrow D 2). A body-shaped hollow right circular truncated cone (the smaller bottom surface of both bottom surfaces is located below), and a hollow straight cylinder (straight line) formed such that the lower edge is connected to the upper edge of the lower portion 45b. And an upper portion 45a having a shape of a rotating body centering on 42. A discharge outlet 43 is formed at the lower end of the hopper 45 (lower end of the lower portion 45 b), and an opening 44 is formed at the upper end of the hopper 45 (upper end of the upper portion 45 a). Is communicated with the outside by a discharge outlet 43 and an opening 44. Here, the hopper 45 has an internal volume of about 20 liters.

The mounting plate 47 includes first plate members 47a1, 47a2, 47a3 whose main surfaces are arranged substantially parallel to each other, and second plate members 47b1, 47b2, whose main surfaces are arranged substantially parallel to each other. 47b3, and the main surfaces of the first plate members 47a1, 47a2, 47a3 and the second plate members 47b1, 47b2, 47b3 are substantially along the vertical direction. The first plate members 47a1, 47a2, 47a3 are arranged at substantially equal intervals, and the second plate members 47b1, 47b2, 47b3 are also arranged at substantially equal intervals. The main surfaces of the first plate-like members 47a1, 47a2, 47a3 and the main surfaces of the second plate-like members 47b1, 47b2, 47b3 intersect so as to be substantially orthogonal (from above as shown in FIG. 2A). As can be seen, the first plate-like members 47a1, 47a2, 47a3 and the second plate-like members 47b1, 47b2, 47b3 are combined in a so-called cross-beam shape, and the first plate-like member 47a2 and the second plate-like member. 47b2 intersects along the straight line 42.) The cross-sectional shape of the mounting plate 47 by a plane perpendicular to the straight line 42 is substantially point-symmetric with respect to the point where the straight line 42 and the plane intersect. The mounting plate 47 formed by the first plate-like members 47a1, 47a2, 47a3 and the second plate-like members 47b1, 47b2, 47b3 has two planes perpendicular to the straight line 42 (virtual surfaces that are separated from each other). The upper edge (the upper edge of all of the first plate members 47a1, 47a2, 47a3 and the second plate members 47b1, 47b2, 47b3) is in contact with the upper plane of the plane, and the lower edge ( The first plate-like members 47a1, 47a2, 47a3 and the second plate-like members 47b1, 47b2, 47b3 are all in contact with each other.
Note that the mounting plate 47 is disposed mainly in the lower portion 45b of the lower narrow shape of the hopper 45 (see FIG. 4 described later), but the outer edge of the mounting plate 47 is attached to the inner surface of the hopper 45 (lower portion 45b). As a result (for example, welding), the mounting plate 47 is supported by the hopper 45.

The baffle portion 49 is attached to the first plate-like member 47a2 and the second plate-like member 47b2, and has a square pyramid having a substantially square bottom surface (here, substantially horizontal) (the axis of this square pyramid is on the straight line 42). The quadrangular prisms are arranged so that the bottom surface of the quadrangular prism is downward and the apex is upward, and two of the four sides extending from the apex of the quadrangular pyramid to the bottom surface are the first plate members 47a2. And the remaining two are substantially present in the second plate-like member 47b2. In practice, the baffle portion 49 has a bottomless (bottom open) hollow rectangular quadrangular pyramid shape, and has a wall portion only on the four side portions of the rectangular pyramid (that is, A concave portion is formed when viewed from the payout opening 43. By using such a concave portion, when the pressure rise due to the backfire from the payout opening 43 occurs, the pressure rise can be received and absorbed. ). Each of the four wall portions corresponding to the four side portions of the square pyramid is formed of a plate-like member having the same shape and size (the isosceles triangle having the same main surface), and the first plate-like member 47a2 and the second plate member 47b2 are attached to both members (first plate member 47a2 and second plate member 47b2) so as to cross over.
The baffle portion 49 has a straight quadrangular pyramid axis formed on the straight line 42 and the bottom surface portion is directed downward, so that the substantially cylindrical discharge port 43 having the straight line 42 as an axis is discharged. At least of a projection region projected in a direction parallel to the direction (here, a direction parallel to the straight line 42) (a right circular cylinder shape drawn by the trajectory of the payout opening 43 when the payout opening 43 moves in parallel along the straight line 42). It is arranged inside the hopper 45 so as to exist in a part.

FIG. 4 is a cross-sectional view showing the mounting plate 47 and the baffle portion 49 disposed inside the hopper 45 (FIG. 4A is a cross-sectional view taken along the line AA similar to FIG. 3A). For ease of explanation, the cross section of the hopper 45 is a cross sectional view taken along the line QQ in FIG. 2A. FIG. 4B is a cross sectional view taken along the line BB similar to FIG. It is sectional drawing which shows. With reference to FIG. 4, the flow of the raw material powder 91 (not shown in FIG. 4) in the hopper 45 will be described.
The raw material powder 91 is put into the hopper 45 through the opening 44 formed in the upper part of the hopper 45 and stored. The stored raw material powder 91 is gradually discharged from the discharge outlet 43 formed at the bottom (lower part) of the hopper 45 to the transfer pipe 53 (the upper end). In response to the discharge of the raw material powder 91 from the discharge port 43, the raw material powder 91 existing above the discharge port 43 descends in the direction of the discharge port 43 due to gravity (finally discharged from the discharge port 43). ), The lowering is communicated in the vertical direction formed by the first plate members 47a1, 47a2, 47a3, the second plate members 47b1, 47b2, 47b3, and the baffle portion 49 in the inside 46 of the hopper 45. Through the space W (for example, in FIG. 2A, the first plate-like members 47a1, 47a2, 47a3, the second plate-like members 47b1, 47b2, 47b3, and the baffle 49 in the interior 46 of the hopper 45). After joining in the lower joining space Z, it is performed by paying out from the payout opening 43.

Using the present apparatus 11 described in this way, a backfire simulation state that is close to the case where a backfire occurs is formed, and the state of the apparatus 11 in the backfire is confirmed in a simulated manner. In the backfire, backfire is transmitted from the lance part 81 through the hose part 71, the ejector 61 and the transfer pipe 53 to the discharge port 43 of the hopper 45 to the inside 46, and the pressure in the inside 46 increases, thereby opening the hopper 45. The raw material powder 91 is ejected from 44. In order to form a state similar to the pressure increase in the inside 46 of the hopper 45 due to the backfire, the apparatus 11 is operated here (pressure 0.5 MPaG (gauge pressure), oxygen gas with a flow rate of 25 Nm ³ / h is ejected by the ejector 61). And the nozzle portion 85 is closed in a state where the raw material powder 91 is stored in the hopper 45. The nozzle portion 85 was closed by conducting a test with various diameters of the communication pipe 51 (a hollow pipe having a substantially circular cross section perpendicular to the longitudinal direction. The pipe diameter is constant in all portions. The vicinity of the other end (the end opposite to the one end (the end communicating with the transfer pipe 53) is open) is bent slightly downward, but this bent portion is inside the communication pipe 51. The influence on the fluid flowing through the flow path is negligible.) The length of the communication pipe 51 is about 80 mm, and the vicinity of the one end of the communication pipe 51 is connected to the transfer pipe 53 substantially vertically (the longitudinal direction of the communication pipe 51 is substantially horizontal here). Yes, and substantially perpendicular to the longitudinal direction of the substantially vertical transfer pipe 53). The results are shown in FIG. The transfer pipe 53 is a hollow pipe having a substantially circular cross section perpendicular to the longitudinal direction (the pipe diameter (inner diameter is 20 mm) is constant in all portions).

In FIG. 5, “caliber (mm)” indicates the inner diameter of the communication pipe 51, and “discharge state from the safety device” indicates the ejection of the raw material powder 91 via the communication pipe 51 when the nozzle portion 85 is closed. (Whether or not the hopper has been ejected) indicates whether or not the raw material powder 91 has been ejected from the opening 44 of the hopper 45 when the nozzle portion 85 is closed. (Note that the description in “Presence / absence of ejection from hopper” describes two types of contents as described in “Description 1 / Description 2”. 47 shows the result when attached to 47, and description 1 shows the result when the baffle 49 is removed from the attachment plate 47).
From this blockage experiment of the nozzle portion 85, even when any of the communication pipes 51 having an inner diameter of 5 to 50 mm is used, the raw material powder 91 is ejected (released) via the communication pipe 51, thereby opening the hopper 45. It is understood that the ejection of the raw material powder 91 from 44 is prevented or reduced. However, in the case where the inner diameter is less than 10 mm, since the raw material powder 91 may be ejected from the opening 44 of the hopper 45 (when the baffle 49 is removed from the mounting plate 47), the inner diameter is preferably 10 mm or more. It became clear.
On the other hand, when the inner diameter exceeds 50 mm, there is a problem that the raw material powder 91 leaks through the communication pipe 51 even when the nozzle portion 85 is not closed.
From the above, the inner diameter of the communication pipe 51 is suitably 10 mm to 50 mm.

  As described above, the apparatus 11 includes the raw material powder 91 including the combustible powder (here, metal powder) and the refractory powder (here, the refractory aggregate powder), and the combustion-supporting carrier gas (here. Is a thermal spraying apparatus that forms a refractory composition by injecting and burning the mixture to form a refractory composition, which stores the raw material powder 91 and discharges the raw material powder 91. A hopper 45 having an outlet 43 at the bottom, and the raw material powder 91 is sucked from the outlet 43 by the flow of the pressurized carrier gas (oxygen gas), and the carrier gas (oxygen gas) and the raw material powder 91 are And an ejecting means (in this case, composed of a hose part 71 and a lance part 81) for injecting the mixture produced by the ejector 61. From exit 43 The raw material powder transfer channel serving transfer tube 53 for transferring the raw material powder 91 to Jekuta 61, is provided with a fresh air communication portion serving communicating pipe 51 communicating with the outside air, a thermal spray apparatus.

The communication pipe 51 serving as the outside air communication portion is constituted by a pipe having one end communicating with the outside air and the other end communicating with the transfer pipe 53 serving as the raw material powder transfer path.
Further, the flow path sectional area S1 of the raw material powder transfer channel serving the channel cross section area S2 of the transfer tube 53 for (314 mm ² in this case) outside-air connection unit serving communication pipe 51 (176.6mm ² in this case) The ratio (S1 / S2 = 0.5624) is 0.05 or more and 1.0 or less. Here, the flow passage cross section of the communication pipe 51 serving as the outside air communication portion has a substantially circular shape with a diameter of 10 mm to 50 mm.

In addition, the flow direction of the raw material powder 91 at the discharge port 43 when the raw material powder 91 is discharged from the discharge port 43 of the hopper 45 toward the raw material powder transfer path (transfer pipe 53) is The projection area of the payout opening 43 in the direction parallel to the straight line 42 (the direction of the straight straight axis formed by the payout opening 43) (here, the direction parallel to the straight line 42). A baffle portion 49 serving as a baffle member disposed in the hopper 45 so as to be present in at least a part of a right columnar shape drawn by the trajectory of the discharge outlet 43 when moving in parallel along Is.
In addition, the entire lower baffle 49 (in this case, the axis is on the straight line 42 (the apex is directed upward)) and the baffle portion 49 having a rectangular quadrilateral shape in which the horizontal cross-sectional area increases monotonously from the upper side to the lower side. A lower enlarged portion), and any horizontal cross section that is an arbitrary cross section in the horizontal direction is projected onto any horizontal cross section positioned below the arbitrary horizontal cross section. The baffle part 49 which is a baffle member has a downward enlarged part which exists in the inside of a horizontal cross section.

Then, the baffle portion 49 serving as the baffle member is formed on the hopper 45 by the mounting plate 47 which is constituted by a plate-like member disposed so that the main surface is substantially along the vertical direction and is disposed inside the hopper 45. It can be attached.
The mounting plate 47 serving as the mounting member includes first plate members 47a1, 47a2, 47a3 and second plate members 47b1, 47b2, 47b3 whose main surfaces intersect each other.

It is the schematic which shows one Embodiment of the thermal spraying apparatus (this apparatus) of this invention. It is a figure which shows a hopper part. FIG. 3A is a cross-sectional view showing only the mounting plate and the baffle portion in the AA cross section of FIG. 2A, and FIG. 3B is a cross-sectional view of the BB cross section in FIG. It is sectional drawing which shows only a board and a baffle part. It is sectional drawing which shows the place which has arrange | positioned the attachment plate and the baffle part inside a hopper. It is a figure which shows the experimental result which experimented the state of this apparatus in the backfire simulation state near the case where a backfire occurred.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 This apparatus 21 Oxygen supply part 23 Oxygen cylinder 25 Pressure adjustment valve 27 Flowmeter 29 Flow adjustment valve 31 Emergency stop part 33 Emergency shut-off valve 35 Emergency stop switch 39 Check valve 41 Hopper part 42 Straight line 43 Discharge outlet 44 Opening 45 Hopper 45a Upper part 45b Lower part 46 Inner 47 Mounting plate 47a1, 47a2, 47a3 First plate-like member 47b1, 47b2, 47b3 Second plate-like member 49 Baffle part 51 Communication pipe 53 Transfer pipe 61 Ejector 63 Nozzle 65 Internal space 67 Outlet 71 Hose Part 81 Lance part 83 Pipe part 83a One end 83b The other end 85 Nozzle part 91 Raw material powder 98 Refractory wall surface

Claims (8)

A thermal spraying apparatus that mixes raw material powder containing combustible powder and refractory powder and a combustion-supporting carrier gas into a mixture, and jets and burns the mixture to form a refractory composition. And
A hopper having a bottom outlet for storing the raw material powder and discharging the raw material powder;
An ejector that sucks the raw material powder from the discharge outlet by the flow of the pressurized carrier gas and mixes the carrier gas and the raw material powder to form the mixture;
Injection means for injecting the mixture produced by the ejector;
With
The thermal spraying apparatus which provided the external air communication part connected to external air in the raw material powder transfer path which transfers this raw material powder from this discharge outlet to this ejector.       2. The thermal spraying device according to claim 1, wherein the outside air communication portion is constituted by a pipe having one end communicating with the outside air and the other end communicating with the raw material powder transfer path.       The ratio (S1 / S2) of the flow path cross-sectional area S1 of the outside air communication portion to the flow path cross-sectional area S2 of the raw material powder transfer path is 0.05 or more and 1.0 or less, according to claim 1 or 2. The thermal spraying apparatus described.       The thermal spraying device according to claim 3, wherein a cross section of the flow path of the outside air communication portion is a substantially circular shape having a diameter of 10 mm to 50 mm.       The thermal spraying according to any one of claims 1 to 4, comprising a baffle member disposed inside the hopper so as to exist in at least a part of a projection area of the discharge outlet in a direction parallel to a discharge direction. apparatus.       Any horizontal cross section that is a lower enlarged portion that monotonously increases as the horizontal cross-sectional area goes from the top to the bottom, and that is an arbitrary horizontal cross section that is an arbitrary cross section in the horizontal direction, is located below the arbitrary horizontal cross section. The thermal spraying device according to claim 5, wherein the baffle member has a lower enlarged portion that exists in any of the horizontal cross sections even when projected onto the horizontal cross section.       7. The structure according to claim 5, wherein the baffle member is attached to the hopper by a mounting member that is configured by a plate-like member that is disposed so that a main surface thereof is substantially along the vertical direction. The thermal spraying apparatus described.       The thermal spraying device according to claim 7, wherein the attachment member includes a first plate-like member and a second plate-like member whose main surfaces intersect each other.

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