JPH04283646A - Method for detecting damage of steam piping of powder humidity controller - Google Patents

Abstract

PURPOSE:To always detect the abnormality of steam piping during operation by continuously measuring the change of the internal pressure of a rotary apparatus during operation to calculate the correlation with a rotary cycle. CONSTITUTION:Steam is subjected to feedback control by a steam pressure controller 4 and the moist powdered coal in a rotary cylinder 1 is indirectly heated from a main pipe 17 through a plurality of steam supply branch pipes 20 to be discharged from steam discharge pipes 21. The steam generated from the moist powdered coal heated in the cylinder 1 is carried from the cylinder 1 at a constant flow rate by the carrier gas blown in the cylinder 1 to be discharged from a flue 25 through an exhaust pipe 22, a dust collector 31 and an exhaust blower 23 while the dust in the steam is removed. Herein, the interior of the cylinder 1 is controlled to + or -5mmAq by a pressure gauge 26, a pressure control valve 24 and a pressure controller 5. The change cycle of the pressure in the cylinder 1 measured at a constant time interval is compared with the rotary waveform signal calculated by the rotation detector 30 of the cylinder 1 by a data analyser 7a to judge the presence of the damage of steam piping.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting damage to steam piping in a moisture control device for pulverized coal used as raw material for coke ovens.

0002

2. Description of the Related Art In general, the following methods are available for detecting damage to piping caused by cracks or abrasion in piping for heating steam or the like in a rotary powder/grain humidifier. One is to stop the humidity control device once and apply 5kg/cm from the heat medium inlet of the heat medium piping.
2. Inject dry air or nitrogen gas with a pressure of about 2. At this time, the drain outlet, which is the outlet side of the heat medium piping, is completely sealed in advance with a blind flange or the like. This method involves leaving the pipe in this state for several hours and detecting changes in the internal pressure of the pipe.

Another method is to have a person enter the equipment and visually inspect each pipe one by one.

0004

[Problem to be solved by the invention] However, once the humidity control device is stopped, dry air or nitrogen gas with a pressure higher than normal pressure is charged from the heat medium inlet of the heat medium piping, and changes in internal pressure are investigated. In the method where a person enters the device and visually inspects it, it is necessary to stop the humidity control device periodically for about one day once a month. Furthermore, even if an abnormality in the steam piping is discovered due to a pressure change, it is difficult to determine which piping among the many pipings installed in the circumferential direction of the cylindrical device is abnormal. Furthermore, with the visual confirmation method, it is necessary to clean the inside of the device beforehand, and
It takes a long time to check each pipe one by one, which is a waste of time.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a technique for detecting piping damage in a powder humidity control device during operation of the device.

[0006]

[Means for Solving the Problems] That is, the present invention provides a powder humidity control device that evaporates moisture in a powder or granular material such as pulverized coal by indirect heating in a rotating device having steam piping. Continuously measures changes in internal pressure within the device,
This is a method for detecting steam piping damage in a powder humidity control device, which is characterized by determining the correlation with the rotation period.

[0007]

[Operation] The operation of the present invention will be explained based on FIG. In FIG. 1, 1 is an inclined rotating cylinder, 9 is a carrier gas (air) intake port, 10 is a carrier gas supply pump, 11 is a carrier gas flow rate adjustment valve, 13 is a carrier gas supply pipe, and the carrier gas is a carrier gas flow rate. It is blown into the rotary cylinder 1 from the inlet of the inclined rotary cylinder 1 while being feedback-controlled to a constant flow rate by the control device 2 . Next, 15 is wet pulverized coal 14
storage hopper, 16 is a measuring device for cutting out powdered coal from the hopper, and wet powder 14 in the hopper is controlled by a control device 16 for cutting out powder quantitatively.
The feedstock is fed back to a constant flow rate and cut out, and continuously charged into the rotary cylinder from the inlet of the tilted rotary cylinder.

Further, 17 is a main steam supply pipe, 18 is a supply steam pressure gauge, and 19 is a steam pressure control valve.
After passing through a plurality of steam supply branch pipes from 7 to indirectly heat the wet pulverized coal in the rotating cylinder 1, it is discharged as drain from a steam discharge branch pipe 21. In this way, 1 part of wet pulverized coal is placed in 1 part of the rotating cylinder.
4 is heated and is accompanied by a carrier gas that is blown into the rotating cylinder at a constant flow rate, and is sucked and removed from one side of the rotating cylinder 1 by an exhaust pipe 22, a dust collector 31, and an exhaust blower 23. After that, it is released into the atmosphere from the chimney 25.

Here, the inside of the rotating cylinder is adjusted to ±5 mmAq, preferably -1 to -2 mmAq by the rotating cylinder internal pressure gauge 26, the rotating cylinder internal pressure control valve 24, and the rotating cylinder internal pressure control device 5.
controlled by. This is to prevent the carrier gas containing dust from blowing out from the rotating cylinder 1 to the surrounding area. The rotating cylinder is driven by a rotating cylinder driving gear 2 by a rotating driving motor 27.
8. The rotary cylinder rotates via a driven gear 29, and the rotation speed is detected by a rotation detector 30 (such as a pulse generator) connected to the drive gear 28, etc., and is feedback-controlled by the rotation speed control device 6.

[0010] According to the present invention in the above configuration, during operation of the humidity control device, (A) the carrier gas flow rate control valve is operated for a period of time required to rotate at least a plurality of times even at fixed time intervals; 11 and the opening degree of the rotary cylinder internal pressure control valve 24 are automatically locked to the current opening degree according to the output signal of the control valve lock command/release command transmitting device 7b.

(B) The waveform of the temporal change in the internal pressure measured within the above-mentioned time period, that is, the pressure signal (PV) of the pressure control device and/or the control signal (MV) of the control valve, is analyzed by the data analysis device 7a to determine the internal pressure. To calculate the fluctuation period of In this case, the pressure inside the rotating cylinder is as small as ±5 mmAq, but the steam pressure is 5 to 9 kg.
/cm2, the following internal pressure fluctuations occur. In other words, if the damaged steam pipe is located below the rotating cylinder and is covered with a layer of powdered coal, no steam will be blown into the rotating cylinder, or if there is, it will be suppressed to a small amount. However, if the damaged steam pipe is located above the rotating cylinder,
Since it is not covered with a layer of powdered coal and remains exposed, the amount of steam blown into the rotating cylinder increases.

[0012] When a part of the steam piping is damaged in this way, the flow rate of steam blown out from the steam piping into the rotating cylinder has periodicity, although it varies depending on the supplied steam pressure value, the size of the crack, etc. Matches the rotation period of the rotating cylinder. (C) The internal pressure fluctuation period obtained above is compared with the rotation waveform signal (DV) obtained by the rotation detector 30 of the rotating container using the data analysis device 7a, and the internal pressure fluctuation period is determined by adding or subtracting the allowable error from the rotation period. If it is outside the range, it is determined that the steam piping is damaged.

Furthermore, by knowing the rotational position of the rotating cylinder and the position at which the internal pressure within the rotating cylinder increases, it is possible to detect which pipe among the plurality of steam pipes arranged in the circumferential direction is damaged. Although an example in which steam is used as the heat medium has been described above, other gases may be used.

[0014]

Embodiment FIG. 2 shows data showing an embodiment of the present invention, which is data taken from the data analysis device 7a. When the data input to the data analysis device 7a is displayed as a trend in the circumferential direction of the rotating device (0 degrees is a relative point) as shown in Fig. 2 along the time axis, the abnormal pressure value 8 is displayed periodically. I was able to capture it.

FIG. 3 shows the data analysis results of the present invention. In this way, by integrating the number of abnormal value data in the circumferential direction for each cycle based on the data in Figure 2,
It is now possible to early detect abnormalities in steam piping within rotating equipment and abnormal locations in the circumferential direction.

[0016]

[Effects of the Invention] According to the present invention, abnormalities in steam piping can be detected at all times even during operation. Therefore, there is no longer a need for periodic equipment stoppages or long piping inspection times as in the past. Another advantage is that even if an abnormality is discovered, it is possible to determine which pipe is abnormal in a limited manner, rather than in a vague manner as in the past.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.

FIG. 2 is an example of data in the data analysis device of the present invention.

FIG. 3 shows data analysis results of the present invention.

[Explanation of symbols]

1 Inclined rotating cylinder 2 Carrier gas flow rate control device 3 Powdered coal quantitative cut-out control device 4 Steam pressure control device 5 Rotating cylinder internal pressure control device 6 Rotation speed control device 7a Data analysis device 7b Control valve lock command/release command transmitting device 8
Abnormal pressure value 9 Carrier gas (air, etc.) intake port 10
Carrier gas supply pump 11 Carrier gas flow rate adjustment valve 12 Carrier gas flowmeter 13 Carrier gas supply pipe 14a Wet pulverized coal 14b Humidity control charcoal 15 Wet pulverized coal hopper 16 Powdered coal cutting and measuring device 17 Steam supply main pipe 18 Steam supply pressure gauge 19 Steam flow rate Shutoff valve 20 Steam supply branch pipe 21 Steam discharge branch pipe 22 Exhaust pipe inside the rotating cylinder 23 Exhaust blower 24 Pressure control valve inside the rotating cylinder 25 Chimney 26 Pressure gauge inside the rotating cylinder 27 Rotating cylinder drive motor 28 Rotating cylinder driving gear 29 Rotating cylinder Driven gear 30 Rotation detector (pulse generator) 31
dust collector

Claims (1)

[Claims] Claim 1: In a powder humidity control device that evaporates moisture in a powder or granular material such as pulverized coal by indirect heating in a rotating device having steam piping, changes in the internal pressure inside the rotating device during operation are continuously measured. , a method for detecting steam piping damage in a powder humidity control device, characterized by determining a correlation with the rotation period.