JP6882877B2 - Thermal spraying device - Google Patents

Description

The present invention relates to a thermal spraying device for forming a refractory composition.

Conventionally, as a thermal spraying device for forming a fire-resistant composition, a raw material powder containing a flammable powder (for example, metal powder) and a fire-resistant powder (fire-resistant aggregate) is used as a flammable carrier gas (flame-supporting carrier gas). There is known a thermal spraying device that forms a fire-resistant composition by transporting and injecting with oxygen gas) and igniting and melting (for example, Patent Document 1).

In such a spraying apparatus, as described above, the raw material powder containing the flammable powder and the fire-resistant powder is conveyed by the flammable carrier gas and injected to ignite and melt, so that the raw material powder is injected to ignite and burn. A hopper (storage means) that stores the raw material powder by moving the flame of the mixture of the raw material powder and the carrier gas in the direction opposite to the direction in which the raw material powder and the carrier gas are flowing. There was a problem that a so-called "backfire" occurred. When a flashback occurs, the pressure inside the hopper rises abnormally, causing a phenomenon in which the raw material powder is blown up inside the hopper (hereinafter referred to as the "raw material powder blowing up phenomenon"), which may cause a fire or explosion. It was a big problem in. In addition, for example, in the configuration described in Patent Document 1, if the hose portion is bent or the hose portion or the lance portion is clogged with the raw material powder, the pressure inside the hopper rises abnormally and the raw material powder is blown up. There was a problem that occurred.

The Patent Document 1 describes that an outside air communication portion is provided in the raw material powder transfer path from the hopper so that the raw material powder does not blow up in the hopper when a flashback occurs. Further, Patent Document 2 describes that a valve member capable of closing the outlet of the hopper from below is provided so as to be able to move up and down, and when a flashback occurs, the valve member rises to close the outlet. There is.

However, even if the measures described in Patent Documents 1 and 2 are taken, the occurrence of the raw material powder blowing-up phenomenon cannot be completely eliminated.

JP-A-2007-238977 Registered Utility Model No. 3171530

An object to be solved by the present invention is to provide a thermal spraying device capable of eliminating the phenomenon of blowing up raw material powder.

According to one aspect of the present invention, the following thermal spraying apparatus is provided.
"A thermal spraying device for forming a fire-resistant composition by injecting and burning a mixture of a raw material powder containing a fire-resistant powder and a flammable powder and a flammable carrier gas.
A hopper that stores the raw material powder and discharges the raw material powder,
A transport means for mixing the raw material powder discharged from the hopper and the carrier gas and transporting the mixture as a mixture.
An injection means for injecting the conveyed mixture is provided.
A through hole is provided on the side surface of the hopper, and a member having more flexibility than the hopper is provided on the outside of the through hole as a closing member for closing the through hole.
At all times, the closing member is in a state of closing the through hole.
A thermal spraying device characterized in that when the pressure in the hopper rises , a member having more flexibility than the hopper is deformed to open the through hole. "

In the thermal spraying device of the present invention, even if the pressure inside the hopper increases, the pressure is released from the through hole. This makes it possible to eliminate the phenomenon of blowing up the raw material powder.

It is sectional drawing of the main part which shows one Embodiment of the thermal spraying apparatus of this invention. It is the schematic perspective view of the main part which shows the internal structure (lower hopper part) of the thermal spraying apparatus of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a main part showing an embodiment of the thermal spraying apparatus of the present invention.

The thermal spraying apparatus shown in FIG. 1 includes a hopper 20 for storing the raw material powder 10, an ejector 30 as a transport means, and an injection means 40. The raw material powder 10 includes a flammable powder (for example, a metal powder) and a fire-resistant powder (fire-resistant aggregate).

The hopper 20 is a combination of the upper hopper 21 and the lower hopper 22. The upper hopper 21 has an input port 21a for charging the raw material powder 10 in the upper part thereof, and the lower hopper 22 has a payout port 22a in the lower part thereof for discharging the raw material powder 10. The inlet 21a of the upper hopper 21 is provided with a lid member 23 for opening and closing the inlet 21a, and the outlet 22a of the lower hopper 22 is provided with an on-off valve 24 for opening and closing the outlet 22a. The hopper 20 is configured by combining the lower end portion of the upper hopper 21 and the upper end portion of the lower hopper 22 so as to overlap each other. That is, the portion where the lower end portion of the upper hopper 21 and the upper end portion of the lower hopper 22 overlap is a double cylinder portion 25 (double cylinder structure).

To specifically explain the configuration of the double cylinder portion 25, a collar portion 21b is formed on the outer periphery of the lower portion of the upper hopper 21 over the entire circumference. Further, two pins 21c are provided at 180-degree intervals in the circumferential direction from the side surface of the upper hopper 21. Further, two support portions 22b are provided on the outer periphery of the upper portion of the lower hopper 22 at intervals of 180 degrees in the circumferential direction. A hook-shaped support groove 22c is formed in each support portion 22b. Then, by inserting each pin 21c of the upper hopper 21 into each support groove 22c of the lower hopper 22 and rotating the upper hopper 21 in the circumferential direction, each pin 21c is fitted into each support groove 22c, and the upper hopper 21 A double tubular portion 25 is formed in which the lower end portion of the hopper and the upper end portion of the lower hopper 22 overlap each other. If each pin 21c is removed from each support groove 22c by the reverse operation of the above, the hopper 20 can be divided into an upper hopper 21 and a lower hopper 22.

An opening / closing damper 26 is provided as a partition mechanism in the upper hopper 21 above the double cylinder portion 25. The opening / closing damper 26 has a function of partitioning the inside of the hopper 20 into an upper region including an inlet 21a and a lower region including a payout port 22a so as to be openable / closable. That is, when the opening / closing damper 26 is closed, the inside of the hopper 20 is divided into the upper region and the lower region, and when the opening / closing damper 26 is opened, the upper region and the lower region communicate with each other.

Further, the double cylinder portion 25 is located in the lower region, and a through hole 27 is provided in the double cylinder portion 25. The through hole 27 of the double cylinder portion 25 is composed of a combination of through holes 27 provided in the lower end portion of the upper hopper 21 and the upper end portion of the lower hopper 22, respectively, and the through hole 27 on the upper hopper 21 side and the lower hopper 22 side. The through hole 27 is provided so as to be aligned with the radial direction of the hopper 20 when the double cylinder portion 25 is formed. Further, as shown in FIG. 2, a plurality of through holes 27 are provided at equal intervals in the circumferential direction of the hopper 20. As a closing member for closing these through holes 27, a flexible band member (rubber band) 28 is provided so as to surround each through hole 27 from the outside.

Next, the configuration after the ejector 30 will be described. The ejector 30 sucks the raw material powder 10 from the outlet 22a of the hopper 20 by the flow of the pressurized carrier gas (oxygen gas), and the carrier gas and the raw material powder 10 To make a mixture. The injection means 40 is connected to the outlet side of the ejector 30 via a horizontal transfer pipe 50 and a rubber hose 60, and injects the mixture produced by the ejector 30.

Here, the configuration of the ejector 30 will be described in detail. The ejector 30 has a container portion 31 having an internal space communicating with the outlet 22a of the hopper 20 and an internal space of the container portion 31 from the tip of the pressurized carrier gas. It is provided with a tapered ejection nozzle 32 that ejects into the air. That is, in the internal space of the container portion 31, the carrier gas is ejected at high speed from the nozzle hole at the tip of the tapered ejection nozzle 32 toward one end (base end) of the horizontal transfer pipe 50, whereby the internal space of the container portion 31 is formed. Is a negative pressure (here, a pressure lower than the atmospheric pressure). On the other hand, the outlet 22a of the hopper 20 communicates with the internal space of the container portion 31 via a vertical transfer pipe 70. Therefore, the ejector 30 sucks the raw material powder 10 into the internal space of the container portion 31 from the outlet 22a by the flow of the pressurized carrier gas, and ejects the raw material powder and the raw material powder from the nozzle hole at the tip of the ejection nozzle 32. 10 and 10 are mixed in the internal space of the container portion 31 to form a mixture.

In the above configuration, the horizontal transfer pipe 50 and the rubber hose 60 are clogged with the raw material powder, the rubber hose 60 is bent, and a flashback occurs (hereinafter, these are collectively referred to as a flashback or the like), and the pressure in the hopper 20 is increased. When the pressure rises, the pressure is released from the through hole 27 provided in the lower region (double cylinder portion 25). That is, the through hole 27 is always closed by the rubber band 28 as shown in FIG. 1, but when the pressure in the hopper 20 rises, the rubber band 28 faces outward due to the pressure. It is deformed and released, and its pressure is released from the through hole 27. Therefore, the phenomenon of blowing up the raw material powder can be eliminated.

When the raw material powder is additionally charged into the hopper 20 during the thermal spraying construction, the opening / closing damper 26 is closed, and the inside of the hopper 20 includes an upper region including the charging port 21a and a lower region including the payout port 22a. Divide into. By partitioning the inside of the hopper 20 into an upper region and a lower region in this way, even if a flashback or the like occurs during the thermal spraying construction, the phenomenon of blowing up the raw material powder is stopped in the lower region and does not reach the upper region. Therefore, the raw material powder can be safely charged into the hopper 20 even during the thermal spraying construction.

Specifically, in the past, there was a case where the raw material powder was put into the hopper in a batch system by interrupting the thermal spraying work because of concern about the occurrence of the raw material powder blowing-up phenomenon. That is, the raw material powder is put into the hopper before the start of the thermal spraying work, then the thermal spraying work is started, the thermal spraying work is interrupted when the raw material powder in the hopper runs out, and the raw material powder is put into the hopper again. In some cases, batch-type work was being performed. It is preferable that the raw material powder is continuously charged into the hopper during the thermal spraying construction in order to improve the efficiency of the construction work. However, if a flashback or the like occurs, the raw material powder is blown up by the hopper. , The worker who puts the raw material powder into the hopper is in great danger. However, with the configuration of this embodiment, even if a flashback or the like occurs during the thermal spraying construction, by closing the opening / closing damper 26, the phenomenon of blowing up the raw material powder is stopped in the lower region and the upper region is reached. Therefore, it is possible to safely charge the raw material powder into the hopper 20 even during the thermal spraying construction.

Further, even when the pressure in the lower region of the hopper 20 rises due to flashback or the like, the rubber band 28 is deformed and opened outward by the pressure, and the pressure is released from the through hole 27. Therefore, the raw material powder can be safely charged into the hopper 20 even during the thermal spraying work.

In the present embodiment, when the charging of the raw material powder into the hopper 20 is completed, the charging port 21a is closed by the lid member 23, and then the opening / closing damper 26 is opened. As a result, the charged raw material powder naturally falls from the upper region to the lower region, and is further discharged from the discharge port 22a to the ejector 30, so that the thermal spraying work can be continued without any problem.

In the present embodiment, the opening / closing damper 26 is provided as the partition mechanism, but the opening / closing damper 26 may not be provided. However, as described above, it is preferable to provide the opening / closing damper 26 from the viewpoint that the raw material powder can be safely charged into the hopper 20 even during the thermal spraying operation.

Further, in the present embodiment, since the flange portion 21b is provided so as to cover the double cylinder portion 25 provided with the through hole 27 and the rubber band 28 from above, it is discharged through the through hole 27 by flashback or the like. The raw material powder and flame that have been made go downward. Therefore, it is possible to prevent the raw material powder and the flame from coming into direct contact with the operator. Further, by providing the flange portion 21b, dust and dirt are less likely to collect in the double cylinder portion 25, and deterioration of the rubber band 28 can be suppressed.

Further, in the present embodiment, a rubber band 28 is provided as a closing member for closing the through hole 27, and the rubber band 28 is deformed by an increase in pressure due to the occurrence of flashback or the like to open the through hole 27. However, the blocking member can also be a member that is burnt or destroyed and disappears due to the occurrence of flashback or the like. The closing member that disappears in this way can also individually close the through hole 27 from the inside. If the closing member disappears due to flashback or the like, it is necessary to re-install the closing member at the lost part. On the other hand, when a flexible member is used, it can be used continuously, so a flexible member is preferable as the closing member.

Further, although a plurality of through holes 27 are provided in the present embodiment, one through hole may be provided in the present invention. However, in order to efficiently release the pressure due to the occurrence of flashback or the like, it is preferable to provide a plurality of through holes.

Further, since the through hole 27 is intended to release the pressure in the hopper that has risen abnormally, it is preferable that the through hole 27 has a sufficient area for releasing the pressure due to the occurrence of flashback or the like in a short time.

Further, in the present embodiment, the plurality of through holes 27 are closed by the rubber band 28, but each of the plurality of through holes 27 may be closed individually. However, in order to efficiently close the plurality of through holes 27, the closing member is a flexible band provided so as to surround the plurality of through holes 27 from the outside like the rubber band 28 of the present embodiment. It is preferable to use it as a member.

Further, in the present embodiment, the hopper 20 is a divided type divided into an upper hopper 21 and a lower hopper 22, but the hopper 20 may be a normal integrated type. However, if the split type is used as in the present embodiment, the rubber band 28 (closing member) can be easily installed or replaced, so that the split type is preferable.

Further, in the present embodiment, the configuration is provided with the ejector 30, but the present invention is not limited to this. For example, a means for cutting out the raw material powder (for example, a table feeder, a screw feeder, etc.) may be provided under the hopper 20, and the raw material powder may be cut out by the means, and the cut out raw material powder may be conveyed by the carrier gas. ..

Further, in the present embodiment, the carrier gas is ejected by the ejection nozzle 32, but the present invention is not limited to this. For example, in addition to the ejection nozzle 32, a mechanism for ejecting carrier gas may be provided on the downstream side of the outlet 22a or in the hopper 20.

The spraying apparatus of the present invention is flammable such as a coke oven, a converter, a melting furnace, an AOD furnace, a ladle, a tandesh, a vacuum degassing furnace, a brazing wheel, an electric furnace, an incinerator, an induction furnace, a heating furnace, and a glass furnace. It can be used in industrial kilns and the like where metal powder-containing spraying is used.

10 Raw material powder 20 Hopper 21 Upper hopper 21a Input port 21b Collar 21c Pin 22 Lower hopper 22a Outlet 22b Support 22c Support groove 23 Lid member 24 Open / close valve 25 Double cylinder part 26 Open / close damper (partition mechanism)
27 Through hole 28 Rubber band (closing member)
30 Ejector 31 Container 32 Ejection nozzle
40 Injection means 50 Horizontal transfer pipe 60 Rubber hose 70 Vertical transfer pipe

Claims (5)

A thermal spraying device for forming a fire-resistant composition by injecting and burning a mixture of a raw material powder containing a fire-resistant powder and a flammable powder and a flammable carrier gas.
A hopper that stores the raw material powder and discharges the raw material powder,
A transport means for mixing the raw material powder discharged from the hopper and the carrier gas and transporting the mixture as a mixture.
An injection means for injecting the conveyed mixture is provided.
A through hole is provided on the side surface of the hopper, and a member having more flexibility than the hopper is provided on the outside of the through hole as a closing member for closing the through hole.
At all times, the closing member is in a state of closing the through hole.
A thermal spraying device characterized in that when the pressure in the hopper rises , a member having more flexibility than the hopper is deformed to open the through hole.
The transport means
It is an ejector that sucks the raw material powder from the hopper by the flow of the pressurized carrier gas and mixes the carrier gas and the raw material powder to obtain the mixture.
The injection means
The thermal spraying apparatus according to claim 1, wherein the mixture produced by the ejector is ejected. A partition mechanism for partitioning the inside of the hopper into an upper area including an inlet and a lower area including a payout port is provided.
The thermal spraying apparatus according to claim 1 or 2, wherein the through hole is provided in the lower region of the hopper. The through hole is spray apparatus according to any one of claims 1 to 3, characterized in that are provided along the circumferential direction of the hopper.
The hopper includes an upper hopper having the inlet and a lower hopper having the outlet, and has a double-cylinder portion in which a lower end portion of the upper hopper and an upper end portion of the lower hopper overlap.
The partition mechanism is provided above the double cylinder portion.
The thermal spraying device according to claim 3 or 4, wherein the through hole is provided in the double cylinder portion.

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