JPH07158837A - Powder transporting apparatus - Google Patents

Abstract

PURPOSE:To securely detect in an early time clogging of powder by measuring a difference between pressures at two points of a transport tube serving to gas-transport the powder, and actuating an alarming oscillator when variations of the measured difference pressure exceed a set value. CONSTITUTION:Powder in a powder hopper 1 is supplied to an ejector 4 by a rotary valve 2, and is entrained with gas introduced from a gas carrying piping 3 and is transported to a container 7 after passage through a transport tube 5. In this instance, a pressure difference detector 6 for detecting a pressure difference between two points of the transport tube 5 is disposed on the transport tube 5 and a detected output is inputted into a computer 9. When the variations of the difference pressure at the two points A, B exceed a set value in the computer 9, alarming is issued from an alarming generating 10 to open a flow rate adjusting valve 11 for prevention of clogging with the aid of increased carrying gas. When there is not yet eliminated the clogging, an interruption valve 12 is them closed and a purging gas interruption valve 14 is opened to introduce high pressure purging gas for elimination of the clogging of powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder transportation device applied to gas transportation of powder such as pulverized coal.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view of a conventional powder transportation device used for gas transportation of powder such as pulverized coal. In FIG. 1A, the powder stored in the powder hopper 1 is mixed with the gas supplied to the ejector 4 by the rotary valve 2 and introduced from the pipe 3 for the carrier gas, and the powder is fed through the transport pipe 5. It is transported therethrough into the container 7. A differential pressure gauge 6 is arranged in the transport pipe 5 to detect a differential pressure between two points A and B on the way, and a differential pressure gauge between the two points A and B is set via a detection pipe 8. When the value becomes larger than the value, it is determined that the clogging of the powder has occurred between the two points A and B in the middle of the conveying pipe 5, and the alarm transmitter 9 gives an alarm.

[0003]

As described above, in the conventional powder transport device, when the powder is clogged between two points A and B in the middle of the transport pipe 5, the clogging can be detected by the differential pressure gauge 6. However, if a blockage occurs between the other two points C and A, or between the two points B and D, the differential pressure detected by the differential pressure gauge 6 does not become larger than the set value. Not detected by. If the point A is installed adjacent to the ejector 4 and the point B is adjacent to the container 7, it is possible in principle to detect where the transport pipe 5 is clogged. . However, in such a powder transportation device, the flow rates of the powder and the carrier gas are not always constant in practice, and generally change with the load fluctuation of the powder transportation device. Since it also fluctuates greatly, it is necessary to set the set value of the differential pressure for detecting clogging to a sufficiently high value. That is, FIG. 3B shows the transport pipe 5 when the powder supply amount and the carrier gas flow rate are changed.
The differential pressure and the set value of the differential pressure for detecting clogging are shown.When the flow rate of powder supply amount or carrier gas is small, the difference between the differential pressure and the set value during normal operation is shown. Is too large, the clogging of the powder in the transport pipe 5 cannot be detected early.

[0004]

A powder transporting device according to the present invention is intended to solve the above problems, and a differential pressure gauge for measuring a differential pressure between two points in a transport pipe for transporting powder by gas.
An alarm transmitter that issues an alarm when the fluctuation range of the differential pressure measured by the differential pressure gauge becomes equal to or greater than a set value.

Further, the powder transport apparatus according to the present invention comprises a differential pressure gauge for measuring a differential pressure between two points in a transport pipe for transporting powder by gas, and a fluctuation range of the differential pressure measured by the differential pressure gauge. A feature is a configuration including an alarm transmitter that issues an alarm when the ratio of the differential pressure to the average value is equal to or greater than a set value.

Further, the powder transport apparatus according to the present invention is a differential pressure gauge for measuring a differential pressure between two points in a transport pipe for transporting powder by gas, and a fluctuation range of the differential pressure measured by the differential pressure gauge or An alarm transmitter that issues an alarm when the ratio between the fluctuation range of the differential pressure and the average value of the differential pressure is greater than or equal to the set value, and the flow rate of the carrier gas that conveys the powder in gas is automatically increased when the above alarm is issued. Alternatively, it is characterized by a configuration including means for automatically reducing the amount of powder supplied.

Further, the powder transporting apparatus according to the present invention comprises a differential pressure gauge for measuring the differential pressure between two points in a transport pipe for transporting powder by gas, and a fluctuation range of the differential pressure measured by the differential pressure gauge or When the ratio between the fluctuation range of the differential pressure and the average value of the differential pressure becomes equal to or greater than the set value, an alarm transmitter that issues an alarm, and when the alarm is issued, the purging gas is used instead of the carrier gas that gas-transports the powder. And a means for introducing it into the transportation pipe.

[0008]

That is, in the powder transport apparatus according to the present invention,
The differential pressure between two points in a transport pipe that transports powder by gas is measured by a differential pressure gauge, and when the fluctuation range of the measured differential pressure exceeds a set value, an alarm transmitter will issue an alarm. When the powder is not clogged in the pipe, the fluctuation of the differential pressure between the two points in the transport pipe is small, but when the powder starts to stay at the bottom of the transport pipe, the flow velocity of the carrier gas that transports the powder by gas increases. The fluctuation range of the differential pressure becomes large because the powder that has started to stay is suspended and conveyed. When the transport pipe is clogged with powder, the fluctuation range of the differential pressure gradually increases while repeating such retention and transportation by floating. Therefore, by monitoring the fluctuation range of the differential pressure and issuing an alarm, the clogging of the powder can be detected early even when the load fluctuation in the transport pipe is large.

Further, in the powder transport apparatus according to the present invention, the differential pressure between two points in the transport tube for transporting the powder gas is measured by the differential pressure gauge, and the fluctuation range of the differential pressure and the average of the differential pressure are measured. When the ratio with the value exceeds the set value, the alarm transmitter issues an alarm.By monitoring the ratio between the fluctuation of the differential pressure and the average value of the differential pressure and issuing the alarm, Even if the load fluctuation is large, the clogging of the powder can be detected early.

Further, in the powder transport apparatus according to the present invention, the differential pressure between the two points in the transport tube for transporting the powder gas is measured by the differential pressure gauge, and the differential pressure fluctuation width or differential pressure fluctuation measured. When the ratio between the width and the average value of the differential pressure exceeds the set value, the alarm transmitter issues an alarm and automatically increases the flow rate of the carrier gas that conveys the powder as a gas, or automatically supplies the powder. Even if the load fluctuation in the transport pipe is large by monitoring the differential pressure fluctuation range or the ratio between the differential pressure fluctuation range and the average differential pressure value and issuing an alarm, The clogging can be detected at an early stage, and the clogging can be automatically cleared by increasing the flow rate of the carrier gas or decreasing the powder supply amount.

Further, in the powder transport apparatus according to the present invention, the differential pressure between the two points in the transport tube for transporting the powder by gas is measured by the differential pressure gauge and the fluctuation width of the differential pressure or the fluctuation of the differential pressure is measured. When the ratio between the width and the average value of the differential pressure exceeds the set value, the alarm transmitter issues an alarm and the purge gas is introduced into the transport pipe instead of the carrier gas that transports the powder by gas. By detecting the fluctuation range of the differential pressure or the ratio between the fluctuation range of the differential pressure and the average value of the differential pressure and issuing an alarm, the clogging of the powder can be detected early even if the load fluctuation in the transport pipe is large. Moreover, by introducing the purging gas into the transportation pipe, the clogging can be automatically cleared.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are explanatory views of a powder transport device according to an embodiment of the present invention. In the figure, the powder transport device according to the present embodiment is used for transporting powder gas such as pulverized coal. Reference numeral 1 in the figure is a powder hopper, 2 is a rotary valve, 3 is a carrier gas pipe, 4 is an ejector, 5 is a powder transportation pipe, 6 is a differential pressure gauge, 7 is a container, 8 is detection pipe, 9 is a computer (computer), 10 is an alarm transmitter,
Reference numeral 11 is a carrier gas flow rate adjusting valve, 12 is a carrier gas cutoff valve, 13 is a purge gas pipe, and 14 is a purge gas cutoff valve. The powder stored in the powder hopper 1 is mixed with the gas supplied to the ejector 4 by the rotary valve 2 and introduced from the carrier gas pipe 3, and is transported into the container 7 through the transport pipe 5. To be done. A differential pressure gauge 6 is arranged on the transport pipe 5 to detect a differential pressure between two points A and B on the way, and a differential pressure gauge 6 is input to a calculator 9 via an output pipe 8. . In the computer 9, the fluctuation width X of the differential pressure between the two points A and B, the average value Y of the absolute values of the differential pressure, and the ratio Z of these X and Y.
= X / Y is continuously calculated, and when the value of the fluctuation range X or the ratio Z exceeds the preset set values X ₀ and Z ₀ , an alarm is issued from the alarm transmitter 10, and at the same time as the alarm is issued. The carrier gas flow rate adjusting valve 11 is opened to increase the carrier gas flow rate. Then, if the alarm is still being issued after the lapse of a certain period of time, the rotation speed of the rotary valve 2 is slowed to reduce the powder supply amount, and a certain period of time has elapsed. If the alarm still continues after that, the shutoff valve 12 for the carrier gas is closed and the shutoff valve 14 for the purge gas is opened to introduce the high-pressure purge gas into the powder transport pipe 5. The clogging of the powder in the transport pipe 5 is removed.

When the transport pipe 5 is not clogged, the fluctuation range X of the differential pressure is small, but when the powder starts to stay at the bottom of the transport pipe 5, the flow velocity of the carrier gas increases, and the powder starts to stay. Since the particles are floated and conveyed, the fluctuation of the differential pressure becomes large. In general, when clogging occurs in the transport pipe 5, the fluctuation width X of the differential pressure gradually increases while repeating such powder retention and transportation. Therefore, by monitoring the fluctuation width X of the differential pressure, it is possible to detect clogging in the transport pipe 5 at an early stage. In particular, by monitoring the ratio between the fluctuation range X of the differential pressure and the average value Y of the absolute values of the differential pressure, the clogging can be detected early even when the fluctuation of the load is large. As shown in FIG. 2, the fluctuation range X of the differential pressure and the ratio Z of the fluctuation range X of the differential pressure and the average value Y of the absolute values of the fluctuation ranges increase remarkably when the transport pipe 5 starts to be clogged. When the set values X _{0 and} Z ₀ are reached, an alarm is issued and the flow rate of the carrier gas is immediately increased. Therefore, the fluctuation width X and the average value Y of the differential pressure are reduced to substantially the same values as before clogging, and the transport pipe Blockage of 5 is prevented. Note that the average value Y of the differential pressures also increases slightly during this period, but the increase of the average value Y is small, so early detection by the average value Y of the differential pressures is impossible. As described above, when the clogging of the transport pipe 5 progresses at a high speed, it may not be possible to reduce the fluctuation width X of the differential pressure only by increasing the supply amount of the purge gas, but in that case. By reducing the powder supply amount, the fluctuation width X of the differential pressure is reduced and clogging is prevented. Further, depending on the case, the variation width X of the differential pressure may not be reduced even if any of the measures is taken, and in such a case, if left as it is, the transportation pipe 5 will be completely blocked, and
It takes a lot of work to remove the clogged powder, so
If the two measures are not effective, the carrier gas shutoff valve 12 is closed, the purge gas shutoff valve 14 is opened, and the purge gas is introduced into the transport pipe 5 to remove the clogging and transport it. By preventing the tube 5 from being completely closed, the operation can be restarted within a relatively short time.

In the conventional powder transport device, when the powder is clogged between two points A and B in the middle of the transportation pipe, the clogging can be detected by the differential pressure gauge. When the clogging occurs, it is not detected because the differential pressure detected by the differential pressure gauge does not exceed the set value. If point A is installed adjacent to the ejector and point B is adjacent to the container, it is possible in principle to detect where the transport pipe is clogged. However, in such a powder transport apparatus, the flow rates of the powder and the carrier gas are not always constant in practice, and generally change with the load fluctuation of the powder transport apparatus,
Along with this, the differential pressure also fluctuates greatly, so it is necessary to set the set value of the differential pressure for detecting clogging to a sufficiently high value. That is, when the powder supply amount or carrier gas flow rate is low, the clogging of the powder in the transport pipe must be detected early because the difference between the differential pressure and the set value during normal operation is too large. However, in this powder transporter, such a problem can be solved to enable the early detection of clogging and the automatic removal of clogging regardless of the load or the installation position of the differential pressure gauge. 2 points A on tube 5,
When the differential pressure between B is measured and the fluctuation range X of the differential pressure becomes equal to or greater than the set value, or the ratio Z between the fluctuation range X of the differential pressure and the average value Y of the absolute values of the differential pressure is the set value. In case of above, increase the flow rate of carrier gas until they fall below the set value, further reduce the powder supply amount, and if the differential pressure still does not fall below the set value, purge gas Transport pipe 5
It is possible to automatically detect the clogging of the transportation pipe 5 by automatically introducing it into the inside, and to automatically eliminate the clogging.

[0015]

The powder transport apparatus according to the present invention is configured as described above, and the clogging of the powder can be detected early even when the load fluctuation in the transport tube is large. It becomes possible to detect from a clogged state, and clogging can be easily eliminated.

[Brief description of drawings]

FIG. 1 is a flow system diagram of a powder transportation apparatus according to an embodiment of the present invention.

FIG. 2 is an operation explanatory view showing the operation result.

FIG. 3 (a) is a flow system diagram of a conventional powder transport device, and FIG. 3 (b) is an operation explanatory diagram thereof.

[Explanation of symbols]

 1 Powder Hopper 2 Rotary Valve 3 Carrier Gas Pipe 4 Ejector 5 Powder Transport Pipe 6 Differential Pressure Meter 7 Container 8 Detection Pipe 9 Computer 10 Alarm Transmitter 11 Carrier Gas Flow Control Valve 12 Carrier Gas Shutoff Valve 13 Purge gas piping 14 Purge gas shutoff valve

Claims (4)

[Claims] 1. A differential pressure gauge for measuring the differential pressure between two points in a transport pipe for transporting powder by gas, and an alarm for issuing an alarm when the fluctuation range of the differential pressure measured by the differential pressure gauge exceeds a set value. A powder transportation device comprising a transmitter. 2. A differential pressure gauge for measuring a differential pressure between two points in a transport pipe for transporting powder by gas, and a ratio between a fluctuation range of the differential pressure measured by the differential pressure gauge and an average value of the differential pressure is set. A powder transportation device, comprising: an alarm transmitter that outputs an alarm when the value exceeds a value. 3. A means for automatically increasing the flow rate of a carrier gas for gas-transporting powder or automatically decreasing the supply amount of powder when the alarm is issued. Alternatively, the powder transportation device according to claim 2. 4. The device according to claim 1, further comprising means for introducing a purging gas into the transportation pipe in place of the carrier gas for pneumatically transporting the powder when the alarm is issued. Powder transport device.