JP2020083569A - Powder transporting facility and powder transporting method - Google Patents

Abstract

To prevent blockage of a transport pipe while reducing a gas used amount.SOLUTION: A powder transporting facility 10 includes: a storage tank 11; a powder cutting device 12; a gas supply source 15; a transport pipe 16; a solid-gas ratio setter 17 which sets a solid-gas ratio in a ratio of a limitation solid-gas ratio of gas transportation of powder of 10% or more and 90% or less; a solid-gas ratio controller 20 which controls a gas flow rate and/or powder flow rate so that a solid-gas ratio actual value becomes a solid-gas ratio set value; and first blockage prevention means which increases a transport gas flow rate and/or reduces a powder flow rate on the basis of blockage possibility of the transport pipe 16, and thereby reduces the solid-gas ratio in the transport pipe.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a powder transportation facility and a powder transportation method for supplying powder such as pulverized coal by air current transportation in a solid-gas two-phase form to a cast bed desiliconization facility of a blast furnace.

There are various methods for transporting powder. One of them is air flow transportation in which a powder is fluidized and pressure-fed in a pipe in a mixed state of solid gas and two phases. Since this method transports the powder through a pipe, there is little dust leakage to the outside of the system, the transportation speed can be changed relatively easily, and kinetic energy can be applied to the powder. Taking advantage of this feature, for example, in iron making equipment, it is often used when the components are adjusted by blowing various treatment materials into the hot metal.

In air flow transportation, the weight ratio of solid (powder) and gas, that is, the solid-gas ratio, is important for transporting powder. It is advantageous that the amount of gas used for powder transportation is small in order to reduce the processing cost. However, when the gas flow rate is reduced, the solid-gas ratio increases, and eventually the kinetic energy necessary and sufficient for transporting the powder is lost, and blockage due to the powder occurs in the pipe. This blockage is particularly likely to occur at a bent portion or a rising portion of the pipe, and once the blockage occurs, it takes a lot of time and labor to restore it. For this reason, in terms of transportation cost, it is desirable to transport the powder using the minimum transport gas that does not cause pipe blockage. Since the transportation characteristics are changed due to the aggregation of the gas and the like, there is a problem that the gas is unavoidably supplied excessively and the transportation cost increases.

For example, in Patent Document 1, in order to stably blow pulverized coal into the blast furnace even when the blowing characteristics of the pulverized coal deviate from the set conditions due to operational changes or when various disturbance factors are added, it is necessary to remove the pulverized coal from the blowing tank. A technique for estimating the solid-gas ratio r from the total pressure loss ΔP of the blowing line reaching the supply destination and determining the transport gas flow rate SVg based on the estimated solid-gas ratio r and the powder blowing amount SVi per line is known. Proposed. However, with this method, it is necessary to constantly measure the source pressure and the tip pressure of the transportation piping, and the relationship between the pressure loss and the solid-gas ratio also changes depending on the equipment, so there is the problem that accurate prediction is difficult.

JP-A-11-11671

In powder transportation in which the powder is fluidized and pressure-fed in the pipe by two phases of solid gas, 1) stable transportation without blockage of the pipe, 2) high transportation speed, 3) gas used for transportation It is desirable that the usage amount be reduced as much as possible to minimize the transportation cost, and that 4) when the transportation speed is changed, the transportation speed can be controlled with high accuracy and high response speed. Generally, for stable transportation, the gas flow rate for transportation (transportation speed) may be increased and the solid-gas ratio (flow rate of powder (weight)/flow rate of gas (weight)) may be reduced. However, in this case, the flow rate of gas is large relative to the powder to be transported, and the cost required for transportation increases. Therefore, it is necessary to increase the solid-gas ratio within the range satisfying the transportation function and reduce the gas flow rate required for transportation. In addition, when there is a risk of clogging of the transportation pipe due to various problems or environmental changes, it is important to quickly increase the gas flow rate to increase the flow velocity of transportation and lower the solid-gas ratio to prevent clogging. ..

The present invention has been made paying attention to such a point, and an object thereof is to prevent the clogging of the transportation pipe while reducing the amount of gas used.

In order to solve the above-mentioned problems, the powder transport facility of the present invention has a storage tank for storing powder to be transported, a powder cutting device for cutting out powder from the lower part of the storage tank, and transporting powder. A gas supply source for supplying the gas, and a transportation pipe that connects the gas supply source and a transportation destination of the powder and introduces the powder cut out from the storage tank in the middle thereof. A powder-transporting facility for pneumatically transporting powder in a two-phase form, wherein the solid-gas ratio setter sets a solid-gas ratio within a range of 10% to 90% of a critical solid-gas ratio of powder pneumatic transport. And a solid-gas ratio controller that controls the gas flow rate and/or the powder flow rate so that the actual solid-gas ratio set value becomes the solid-gas ratio set value set by the solid-gas ratio setter. Based on the possibility of blockage, the first blockage prevention means for decreasing the solid-gas ratio in the transportation pipe by increasing the gas flow rate and/or decreasing the powder flow rate is provided.

In an advantageous aspect of the powder transport facility of the present invention, the first blockage prevention means is configured such that when the solid-gas ratio actual value exceeds a predetermined first solid-gas ratio threshold value larger than the solid-gas ratio set value, And/or the gas flow rate is increased and/or the powder flow rate is decreased when the pressure deviation between the actual pressure value and the expected pressure value of the transportation pipe exceeds a predetermined first pressure deviation threshold value. .

In an advantageous aspect of the powder transportation facility of the present invention, when the solid-gas ratio actual value exceeds a predetermined second solid-gas ratio threshold larger than the first solid-gas ratio threshold, and/or the pressure deviation is A second blockage prevention unit is provided for purging the transportation pipe when a predetermined second pressure deviation threshold value larger than the first pressure deviation threshold value is exceeded.

In an advantageous aspect of the powder transportation facility of the present invention, the second blockage prevention means is configured such that when the solid-gas ratio actual value exceeds the second solid-gas ratio threshold value and/or the pressure deviation is the second pressure deviation. There is a purge valve for purging the transportation pipe when the threshold value is exceeded, and the purge valve is an on-off valve that has two positions, an open position and a closed position.

In order to solve the above-mentioned problems, the powder transportation method of the present invention, a storage tank for storing the powder to be transported, a powder cutting device for cutting the powder from the lower portion of the storage tank, and for transporting the powder. A gas supply source for supplying the gas, and a transportation pipe that connects the gas supply source and a transportation destination of the powder and introduces the powder cut out from the storage tank in the middle thereof. A powder transportation method for pneumatically transporting powder in a two-phase form, wherein the solid-gas ratio is set within a range of 10% or more and 90% or less of a critical solid-gas ratio of powder pneumatic transportation. By controlling the gas flow rate and/or the powder flow rate so that the value becomes the set solid-gas ratio, and increasing the gas flow rate and/or decreasing the powder flow rate based on the possibility of blockage of the transportation pipe. This includes lowering the solid-gas ratio in the transportation pipeline.

In an advantageous aspect of the powder transportation method of the present invention, when the solid-gas ratio actual value exceeds a predetermined first solid-gas ratio threshold value which is larger than the set solid-gas ratio, and/or the actual pressure of the transportation pipe. Increasing the gas flow rate and/or decreasing the powder flow rate if the pressure deviation between the value and the expected pressure value exceeds a predetermined first pressure deviation threshold.

In an advantageous aspect of the powder transportation method of the present invention, when the solid-gas ratio actual value exceeds a predetermined second solid-gas ratio threshold larger than the first solid-gas ratio threshold, and/or the pressure deviation is Purging the transport line when a predetermined second pressure deviation threshold greater than the first pressure deviation threshold is exceeded.

According to the powder transport facility and powder transport method of the present invention, by controlling the solid-gas ratio to be at or near the critical solid-gas ratio, the amount of gas used for transportation can be reduced, and low-cost powder Body transport can be realized. Further, when there is a possibility that the transportation pipe may be blocked, the transportation gas flow rate is increased and/or the powder flow rate is decreased, so that the transportation pipe can be prevented from being blocked.

Therefore, according to the present invention, it is possible to prevent clogging of the transportation pipe while reducing the amount of gas used.

It is a schematic block diagram of the powder transportation equipment which showed one Embodiment of this invention. 3 is a graph showing a result of performing solid-gas ratio control using the powder transportation facility having the configuration of FIG. 1.

Hereinafter, embodiments of a powder transportation facility and a powder transportation method of the present invention will be described in detail with reference to the drawings. Here, FIG. 1 is a schematic configuration diagram of a powder transportation facility of one embodiment of the present invention, which is suitable for carrying out the powder transportation method of one embodiment of the present invention.

As shown in FIG. 1, the powder transport facility 10 of the present embodiment mainly includes a storage tank 11, a powder cutting device 12, a powder flow rate setting device 13, a powder flow rate control device 14, and a gas supply device. A source 15, a transportation pipe 16, a solid-gas ratio setter 17, a gas flow rate setter 18, a gas flow rate control device 19, and a solid-gas ratio controller 20 are provided.

The storage tank 11 stores a certain amount of powder to be transported, and is preferably formed in a cone shape having a predetermined angle of repose so that the stored powder efficiently flows from the discharge port at the lower end. Has been done. The inside of the storage tank 11 may be in an atmospheric pressure state, but may be communicated with the transportation pipe 16 via a pressure equalizing pipe 21 as in the illustrated example.

The powder cutout device 12 has a powder cutout mechanism 12a such as a rotary valve and a drive motor 12b for driving the powder cutout mechanism 12a. The drive motor 12b passes through a motor rotation speed control device (inverter) 22. The powder flow rate controller 14 controls the rotation speed. The powder cut out through the powder cutting device 12 is introduced into the transportation pipe 16 through the powder introduction pipe 24 attached to the lower end outlet of the storage tank 11.

The gas supply source 15 is for giving kinetic energy to the powder, and may be the compressor itself, or may be a tank for accumulating the gas pressurized by the compressor. The gas is not particularly limited as long as it is suitable for the powder to be transported, and may be air or an inert gas such as nitrogen.

The transportation pipe 16 connects between the gas supply source 15 and a powder transportation destination, and transports the powder introduced from the storage tank 11 to the transportation destination on the way. Preferably, a gas flow meter 25 of an orifice type or the like and a gas flow rate control valve 26 are provided on the upstream side of the powder introduction pipe 24 in the transportation pipe 16. In this case, the gas used for transportation is controlled by, for example, a feedback method via the gas flow meter 25, the gas flow rate control valve 26, and the gas flow rate control device 19, and merges and fluidizes with the powder at the outlet of the powder introduction pipe 24. Then, it is sent to the destination in the form of gas-solid two-phase.

The powder flow rate is set by the powder flow rate setter 13 according to the demand amount at the destination, etc., and is controlled by the powder flow rate control device 14 in a feedback manner, for example, so as to reach the set powder flow rate. To be done. Specifically, for example, the weight of the storage tank 11 is measured by a weighing device 27 such as a load cell type, and the actual powder flow rate value, which is the change amount of the measured weight per unit time, is measured by the powder flow rate setting device 13. The cutting speed of the powder cutting device 12 is adjusted so as to approach the powder flow rate set value. The cutting speed is controlled by the powder flow rate control device 14 adjusting the rotation speed of the drive motor 12b via the motor rotation speed control device 22.

The gas flow rate is determined so as to have a predetermined solid-gas ratio (powder flow rate (kg/s)/gas flow rate (kg/s)) with respect to the powder flow rate. The solid-gas ratio is set by the solid-gas ratio setter 17 based on the powder flow rate set value set by the powder flow rate setter 13 in the range of 10% or more and 90% or less of the limit solid-air ratio of the air flow of powder. , More preferably 30% or more and 90% or less, further preferably 50% or more and 90% or less, and further preferably 70% or more and 90% or less. Here, the critical solid-gas ratio means the maximum solid-gas ratio at which the transportation pipe 16 is not clogged in a steady state. In other words, the powder flow rate is kept constant and the powder flow rate is set to the gas flow rate. It is a value obtained by dividing by the gas flow rate (minimum gas flow rate) corresponding to the minimum speed (lower limit speed) at which the transport pipe 16 is not clogged when it is reduced. The limit solid-gas ratio can be a value that is empirically or experimentally obtained in the actual powder transportation facility 10 or a value that is theoretically obtained using an estimation formula.

When the solid-gas ratio set value is determined by the solid-gas ratio setter 17, the gas flow rate setter 18 determines the gas flow rate based on the determined solid-gas ratio set value. Specifically, the gas flow rate setting unit 18 obtains the gas flow rate by dividing the powder flow rate set by the powder flow rate setting unit 13 by the solid-gas ratio set value determined by the solid-gas ratio setting unit 17. ..

The solid-gas ratio controller 20 limits the control output value of the gas flow rate by the gas flow rate upper and lower limit limiter 28 so that the solid-gas ratio of the transport pipe 16 (solid-gas ratio actual value) is controlled within a certain range. The flow rate control device 19 controls the gas flow rate control valve 26 based on the limited control output value, for example, in a feedback system. In addition to or instead of this, the solid-gas ratio controller 20 limits the control output value of the powder flow rate by the powder flow rate upper and lower limit limiter 29 so that the solid-gas ratio of the transport pipe 16 is controlled within a certain range. Then, the powder flow rate control device 14 controls the powder cutting speed based on the limited control output value, for example, in a feedback system. By controlling the actual solid-gas ratio to be at or near the critical solid-gas ratio in this manner, the amount of gas used for transportation can be reduced, and low-cost powder transportation can be realized.

However, in the actual powder transportation, the transportation characteristics change due to the adhesion and deposition of the powder on the inner wall surface of the transportation pipe 16, the agglomeration of the powder due to moisture, or the fluctuation of the gas supply amount due to disturbance or the like. Therefore, the transportation pipe 16 may be blocked during the operation near the critical solid-gas ratio. Therefore, the powder transport facility 10 of the present embodiment lowers the solid-gas ratio in the transport pipe 16 by increasing the transport gas flow rate and/or decreasing the powder flow rate based on the possibility of clogging of the transport pipe 16. A first blockage prevention means is provided.

The first blockage prevention unit includes at least one (both in the illustrated example) of the first solid-gas ratio upper limit determiner 30 and the first pressure deviation upper limit determiner 31, and the flow rate changing unit 32.

The first solid-gas ratio upper limit determiner 30 determines whether or not the solid-gas ratio actual value exceeds the first solid-gas ratio upper limit, and when the solid-gas ratio actual value exceeds the first solid-gas ratio upper limit, It is determined that the transportation pipe 16 may be blocked. Instead of or in addition to this, the first pressure deviation upper limit determiner 31 determines, based on the actual pressure value of the transport pipe 16 measured by the pressure gauge 33 and the powder transport amount calculated by the powder transport amount calculator 34, For example, it is determined whether or not the pressure deviation from the predicted pressure value obtained by the pressure calculator 35 including the powder transportation amount-pressure characteristic line exceeds the predetermined first pressure deviation threshold value in the first pressure deviation upper limit judgment device 31. If the pressure deviation exceeds the first pressure deviation threshold value, it is determined that the transportation pipe 16 may be blocked.

The flow rate changing unit 32 performs control for increasing the gas flow rate and/or decreasing the powder flow rate when the first solid-gas ratio upper limit determiner 30 determines that the transportation pipe 16 may be clogged. Run. Further, the flow rate changing unit 32 controls to increase the gas flow rate and/or decrease the powder flow rate when the first pressure deviation upper limit determiner 31 determines that the transportation pipe 16 may be clogged. To execute. In the case where both the first solid-gas ratio upper limit determiner 30 and the first pressure deviation upper limit determiner 31 are provided as in the illustrated example, when it is determined that one of the first solid-gas ratio upper limit determiner 30 and the first pressure deviation upper limit determiner 31 may cause clogging first, It is preferable to perform control to increase the gas flow rate and/or decrease the powder flow rate.

More specifically, the first blockage prevention unit executes one or both of the following 1) and 2) when it is determined that blockage may occur.
1) Turn off the feedback control of gas flow rate control and switch the control output to a predetermined fixed value X (%) larger than the control output value before switching, or add a predetermined fixed value X (%) to the feedback control output. By doing so, the gas flow rate is temporarily increased and the solid-gas ratio is lowered.
2) Turn off the feedback control of the powder flow rate control and switch the control output to a predetermined fixed value Y (%) that is smaller than the control output value before switching, or subtract Y (%) from the feedback control output. Temporarily reduces body flow and lowers the solid-gas ratio.

In the powder transportation facility 10 and the powder transportation method according to the present embodiment, the solid-gas ratio controller 20 performs the solid-gas ratio actual value even while the flow rate changing control (control for reducing the solid-gas ratio) is being performed by the flow rate changing unit 32. When the actual solid-gas ratio value decreases for a certain period of time, it is determined that the possibility of occurrence of blockage of the transportation pipe 16 has been resolved, and the set value of the powder flow rate is set to the original value (before the flow rate is changed). It is preferable to return the value to the value and restart the feedback control, return the set value of the gas flow rate to the original value (before changing the flow rate), and restart the feedback control.

Further, the powder transportation facility 10 of the present embodiment is provided with a second blocking prevention means as a more advantageous aspect. The second blockage preventing means may be configured such that when the solid-gas ratio actual value exceeds a predetermined second solid-gas ratio threshold value that is larger than the first solid-gas ratio threshold value and/or the pressure deviation is higher than the first pressure deviation threshold value. When the large predetermined second pressure deviation threshold is exceeded, that is, when it is determined that the possibility of blockage is higher, the transportation pipe 16 is purged and the gas flow rate is temporarily and rapidly increased to increase the solid-gas ratio. Execute the lowering control.

The second blockage prevention means includes at least one of the second solid-gas ratio upper limit determiner 36 and the second pressure deviation upper limit determiner 37 (both in the illustrated example), and a bypass conduit 38 that bypasses the gas flow rate control valve 26. It has a purge valve 39 installed in the bypass conduit 38 and a purge valve control unit 40. The purge valve 39 is preferably an on/off valve that has two positions, an open position and a closed position, which allows the transportation pipe to be quickly purged.

The second solid-gas ratio upper limit determiner 36 determines whether or not the solid-gas ratio actual value exceeds a predetermined second solid-gas ratio upper limit that is larger than the first solid-gas ratio upper limit, and the solid-gas ratio actual value is determined. Is greater than the second upper limit of the solid-gas ratio, it is determined that the transportation pipe 16 is more likely to be blocked. The second pressure deviation upper limit determination unit 37 determines, for example, the powder transportation amount-pressure characteristic based on the actual pressure value of the transportation pipe 16 measured by the pressure gauge 33 and the powder transportation amount calculated by the powder transportation amount calculator 34. It is determined whether or not the pressure deviation from the expected pressure value obtained by the pressure calculator 35 including the line exceeds a predetermined second pressure deviation threshold value larger than the first pressure deviation threshold value, and the pressure deviation is the second pressure deviation value. If it exceeds the threshold, it is determined that the possibility of blockage is higher.

The purge valve control unit 40 opens the purge valve 39 for a predetermined time, that is, temporarily when the second solid-gas ratio upper limit determiner 36 determines that the possibility of blocking the transportation pipe 16 is higher. When the second pressure deviation upper limit determiner 37 determines that the transportation pipe 16 may be blocked, the purge valve control unit 40 opens the purge valve 39 for a predetermined time, that is, temporarily. When both the second solid-gas ratio upper limit determiner 36 and the second pressure deviation upper limit determiner 37 are provided as in the illustrated example, it is determined that one of them is more likely to block the transportation pipe 16 first. In this case, it is preferable that the purge valve 39 be controlled to be opened. The purge valve control unit 40 may be configured to purge the transport pipe 16 multiple times by opening and closing the purge valve 39 in a pulsed manner multiple times.

According to the powder transportation facility 10 and the powder transportation method of the present embodiment, by controlling the solid-gas ratio to be at or near the critical solid-gas ratio, the amount of gas used for transportation can be reduced and the cost can be reduced. The powder transportation can be realized. Further, when there is a possibility that the transportation pipe 16 may be blocked, the flow rate changing unit 32 of the first blocking prevention unit increases the transportation gas flow rate and/or decreases the powder flow rate, so that the transportation pipe 16 is prevented from being blocked. be able to.

Furthermore, when the actual solid-gas ratio actual value exceeds a predetermined second solid-gas ratio threshold larger than the first solid-gas ratio threshold, and/or the pressure deviation is larger than the first pressure deviation threshold, a predetermined second pressure deviation threshold. According to an advantageous aspect in which the second blockage preventing means for purging the transport pipe 16 when the transport pipe 16 is exceeded, the inside of the transport pipe 16 is more likely to be blocked (the urgency is higher). The gas flow rate can be temporarily and rapidly increased to prevent the occurrence of blockage more reliably and promptly.

FIG. 2 shows an embodiment according to the present invention. In the powder transportation facility having the equipment configuration shown in FIG. 1 and the critical solid-gas ratio measured in the previous experiment being 20, the solid-gas ratio set value is set to 11 (55% of the critical solid-gas ratio). Then, the transportation was started at a powder transportation rate of 50 kg/min. At 5 minutes after the start, the solid-gas ratio exceeded the first solid-gas ratio threshold 13 set by the first solid-gas ratio upper limit determiner, so that the powder and gas feedback control was cut off and the control output was fixed. As a result, the solid-gas ratio returned to 12 or less, and the feedback control was started again 8 minutes after the start. Thereafter, the powder transport rate was gradually increased to 100 kg/min and 150 kg/min. While the transport speed was increasing, the gas flow rate and the powder flow rate were controlled by the solid-gas ratio control of the present invention so as to be in the vicinity of the critical solid-gas ratio, and there was no major problem with the solid-gas ratio, but the transport speed was increased to 150 kg/min. After 27 and 37 minutes from the start, the solid-gas ratio rapidly increased, exceeded the solid-gas ratio 15 set by the second solid-gas ratio upper limit determiner, and pipe clogging was expected, but the purge valve in the bypass line was As a result of the temporary opening and purging of the transportation piping, the solid-gas ratio rapidly decreased, and piping clogging was avoided. After that, transportation was performed at a constant transportation speed of 100 kg/min, but since the solid-gas ratio 12 set by the first solid-gas ratio upper limit determiner was exceeded, the powder and gas feedback control was temporarily cut off and the control output was changed. fixed. After that, since the solid-gas ratio became 12 or less, the feedback control was started again. As a result of a later investigation, it was found that adhered matter adhered to the blow-in nozzle portion at the end of the blow-in pipe, which is the destination of transportation, and the tip portion was about to be blocked.

According to the powder transportation facility and the powder transportation method of the present invention, it is possible to prevent the clogging of the transportation pipe while reducing the amount of gas used.

10 powder transportation equipment 11 storage tank 12 powder cutting device 13 powder flow rate setting device 14 powder flow rate control device 15 gas supply source 16 transport piping 17 solid-gas ratio setting device 18 gas flow rate setting device 19 gas flow control device 20 solid Gas ratio controller 21 Pressure equalizing pipe 22 Motor rotation speed control device 24 Powder introduction pipe 25 Gas flow meter 26 Gas flow rate control valve 27 Weigher 28 Gas flow rate upper/lower limit limiter 29 Powder flow rate upper/lower limiter 30 1st solid-gas ratio upper limit Judgment device 31 First pressure deviation upper limit judgment device 32 Flow rate changing unit 33 Pressure gauge 34 Powder transportation amount calculation device 35 Pressure calculation device 36 Second solid-gas ratio upper limit judgment device 37 Second pressure deviation upper limit judgment device 38 Bypass pipe 39 Purge valve 40 Purge valve control unit

Claims (7)

A storage tank for storing the powder to be transported,
A powder cutting device for cutting powder from the lower part of the storage tank,
A gas supply source for supplying a gas for transporting the powder,
A gas supply source and a powder transportation destination, and a transportation pipe into which the powder cut out from the storage tank is introduced in the middle thereof, and the powder is air-transported in a solid-gas two-phase form. A powder transportation facility that
A gas-solid ratio setter for setting the gas-solid ratio within the range of 10% or more and 90% or less of the limit gas-air ratio of powder air transportation;
And a solid-gas ratio controller that controls the gas flow rate and/or the powder flow rate so that the actual solid-gas ratio value becomes the solid-gas ratio set value set by the solid-gas ratio setter.
Based on the possibility of clogging of the transportation pipe, the first clogging prevention means for decreasing the solid-gas ratio in the transportation pipe by increasing the gas flow rate and/or decreasing the powder flow rate is provided. Transportation equipment. The first blockage prevention unit is configured such that when the solid-gas ratio actual value exceeds a predetermined first solid-gas ratio threshold value that is larger than the solid-solid ratio set value, and/or the actual pressure value and the predicted pressure value of the transportation pipe. The powder transportation facility according to claim 1, wherein the powder transportation facility is configured to increase the gas flow rate and/or decrease the powder flow rate when the pressure deviation from the pressure deviation exceeds a predetermined first pressure deviation threshold value. When the solid-gas ratio actual value exceeds a predetermined second solid-gas ratio threshold that is greater than the first solid-gas ratio threshold, and/or the pressure deviation is a predetermined second pressure that is greater than the first pressure deviation threshold. The powder transport facility according to claim 2, further comprising a second blockage prevention unit that purges the transport pipe when the deviation threshold is exceeded. The second blockage preventing means purges the transportation pipe when the actual solid-gas ratio value exceeds the second solid-gas ratio threshold value and/or when the pressure deviation exceeds the second pressure deviation threshold value. The powder transportation facility according to claim 3, further comprising a valve, wherein the purge valve is an on-off valve that has two positions, an open position and a closed position. A storage tank for storing the powder to be transported,
A powder cutting device for cutting powder from the lower part of the storage tank,
A gas supply source for supplying a gas for transporting the powder,
A gas supply source and a powder transportation destination, and a transportation pipe into which the powder cut out from the storage tank is introduced in the middle thereof, and the powder is air-transported in a solid-gas two-phase form. A method of transporting powder,
Set the solid-gas ratio in the range of 10% or more and 90% or less of the limit solid-air ratio of powder air flow transportation,
The gas flow rate and/or the powder flow rate are controlled so that the solid-gas ratio actual value becomes the set solid-gas ratio,
A powder transportation method characterized in that the solid-gas ratio in the transportation pipeline is lowered by increasing the gas flow rate and/or decreasing the powder flow rate based on the possibility of clogging of the transportation pipeline. When the solid-gas ratio actual value exceeds a predetermined first solid-gas ratio threshold value that is larger than the set solid-gas ratio, and/or the pressure deviation between the actual pressure value and the predicted pressure value of the transportation pipe is a predetermined first value. The powder transportation method according to claim 5, comprising increasing the gas flow rate and/or decreasing the powder flow rate when the pressure deviation threshold value of 1 is exceeded. When the solid-gas ratio actual value exceeds a predetermined second solid-gas ratio threshold that is greater than the first solid-gas ratio threshold, and/or the pressure deviation is a predetermined second pressure that is greater than the first pressure deviation threshold. The powder transportation method according to claim 5 or 6, further comprising purging the transportation pipe when a deviation threshold is exceeded.