JPH11201440A - Ash clogging detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily and accurately detect ash clocking in a hopper, a chute, or the like being provided at the combustion exhaust gas path of a coal boiler or the like. SOLUTION: Ash H in a combustion exhaust gas being delivered from a coal boiler is captured by an electrical dust-collecting machine and is dropped and then is collected at a hopper 1. The ash H that is supplied from the hopper 1 to a blow tank 5 is sent in an air-blowing pipe 7 by fresh air being blown from a blow nozzle 6 and is carried. Temperature in the air-blowing pipe 7 is detected by a thermometer 9 in a pipe, an atmospheric temperature being blown from the blow nozzle 6 is detected by an atmospheric thermometer 10, the value of the difference between both the temperature detection values is compared with a discrimination device 11, and it is judged that ash is clogged in the hopper 1 when the difference value is equal to or less than a setting value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting clogging of ash in a combustion exhaust gas discharged from a coal boiler or the like in a hopper or the like.

[0002]

2. Description of the Related Art Coal and heavy oil are used as fuel for boilers and the like. However, when cheap coal is used as compared with heavy oil, a large amount of ash is generated. Ash in the combustion exhaust gas discharged from the coal boiler is supplied to an electric dust collector or the like to be captured. The captured ash is collected in a hopper and supplied to a blow tank connected to a lower end of the hopper. The blow tank is provided with a blow nozzle on one side and a pneumatic pipe on the other side, but the ash supplied to the blow tank is sent through the pneumatic pipe by the air ejected from the blow nozzle and is sent to the bucket. It is carried out.

[0003] In such an apparatus, the ash that has fallen into the hopper sometimes becomes clogged due to a shelf hanging phenomenon or the like. If ash clogging occurs, with the fuel switched to heavy oil, ash clogging must be resolved by inserting a vacuum tube from inside the blow tank to the hopper outlet, or removing the blow tank and inserting a rod into the hopper outlet. No. In addition, when the detection of the ash clogging is delayed or when it takes time to clear the ash clogging, the ash of the hopper reaches the electric dust collector and is sometimes stopped.

A conventional ash clogging detection device has a limit switch provided in a hopper, and detects ash clogging by switching the switch according to the weight of the deposited ash. However, the detection accuracy of the conventional device is poor, and the detection of the ash clogging may be delayed. On the other hand, as another device for detecting ash clogging in a hopper or the like, for example, Japanese Unexamined Patent Application Publication No.
An apparatus described in Japanese Patent Publication No. 317 is known. In this device, a temperature detection sensor is provided in an ash chute located below a skirt in a combustion chamber, and when a temperature detected by the temperature detection sensor exceeds a set value, it is determined that clogging of the ash chute has occurred. Device. However,
Since the temperature change in the ash chute due to the presence or absence of ash clogging is small, there has been a problem that the detection accuracy is poor.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to quickly and accurately detect clogging of ash in a flue gas discharged from a coal boiler or the like in a hopper or the like.

[0006]

An ash clogging detection device according to the present invention for solving the above-mentioned problems is a device for feeding ash in a combustion exhaust gas into an air supply pipe by an atmosphere ejected from a nozzle.
A pipe thermometer for detecting the temperature in the air supply pipe, an air thermometer for detecting the temperature of the atmosphere, and a difference between a temperature detected by the pipe thermometer and a temperature detected by the air thermometer are set. It is characterized in that a determining means for determining whether or not the value is exceeded is provided. Preferably, the in-pipe thermometer and the atmospheric thermometer are thermocouples.

[0007]

FIG. 1 is a sectional view of an ash clogging detection device according to the present invention. In FIG. 1, reference numeral 1 denotes a hopper for containing ash H in combustion exhaust gas.
Is provided below an electric dust collector (not shown) provided in a combustion exhaust gas path such as a coal boiler. An ash supply valve 2 that is opened and closed by an actuator 3 is provided at an outlet of the hopper 1. Reference numeral 4 denotes a switching valve.

A blow tank 5 is connected to the outlet of the hopper 1 and a blow nozzle 6 for blowing air is provided at a lower end of the blow tank 5. An air supply pipe 7 for discharging ash H in the blow tank 5 is provided at an upper end portion of the blow tank 5, and is opened when the pressure in the air supply pipe 7 exceeds a predetermined value. A ball valve 8 is provided.

An in-pipe thermometer 9 for detecting the temperature in the pneumatic pipe is provided in the pneumatic pipe 7, and an outside thermometer 1 for detecting the temperature of the atmosphere outside the blow tank 5.
0 is provided. The signal of the temperature detection value by the in-pipe thermometer 9 and the signal of the temperature detection value by the atmospheric thermometer 10 are taken into the discrimination device 11, and the discrimination device 11
Is subtracted from the temperature detected by the atmospheric thermometer 10. By this subtraction, the detection accuracy can be improved by compensating for the fluctuation of the temperature detection value by the in-pipe thermometer 9 that occurs with the fluctuation of the atmospheric temperature.

The discriminating device 11 stores a reference temperature signal for discriminating the presence or absence of ash clogging as a set value. The discriminating device 11 compares the set value with the value after the subtraction,
If the value after subtraction exceeds the set value, it is determined that ash clogging has not occurred, and if the value after subtraction is equal to or less than the set value, it is determined that ash clogging has occurred. In this case, when thermocouples are used as the in-pipe thermometer 9 and the atmospheric thermometer 10, since an electric signal can be directly taken in, the discriminating device 11 is used.
Is easy.

Next, the operation of the present apparatus will be described. As shown in FIG. 1, the ash supply valve 2 is normally closed. Ash in the combustion exhaust gas discharged from a coal boiler or the like is captured by passing through an electric dust collector (not shown), and falls and deposits on the hopper 1. When the ash level in the hopper 1 reaches a predetermined value, the switching valve 4 and the actuator 3 operate to open the ash supply valve 2, and the ash H in the hopper 1 is supplied to the blow tank 5.

Next, after the ash supply valve 2 is closed and the pressurized air is blown from the blow nozzle 6, the blow tank 5
Ash H in the space floats. When the pressure in the blow tank 5 reaches a predetermined value, the ball valve 8 opens and the ash H in the blow tank 5 is carried out through the air supply pipe 7 to the outside.

At this time, when ash clogging does not occur in the hopper 1, high-temperature ash H is supplied to the air supply pipe 7, and the temperature detected by the pipe thermometer 9 is, for example, 40 ° C.
And a high value. The discriminating device 11 subtracts the temperature detection value (for example, 20 ° C.) from the temperature detection value (40 ° C.) from the temperature detection value (40 ° C.), and compares the subtracted value (20 ° C.) with a set value (for example, 10 ° C.). . In this case, since the value after subtraction (20 ° C.) exceeds the set value (10 ° C.), it is determined that ash clogging has not occurred.

When ash clogging occurs in the hopper 1,
Since high-temperature ash H is not supplied to the air supply pipe 7, the temperature detected by the pipe thermometer 7 is a low value, for example, 25 ° C. The discrimination device 11 subtracts the atmospheric temperature detection value (20 ° C.) from the temperature detection value (25 ° C.), and compares the subtracted value (5 ° C.) with the set value (10 ° C.). In this case, the value after subtraction (5 ° C.) is equal to or less than the set value (10 ° C.)
The determination device 8 determines that ash clogging has occurred, outputs a signal to the display device 12, and the display device 11 displays the ash clogging and issues an alarm if necessary.

Since the ash clogging detection device of the present invention can detect ash clogging in the hopper at an early stage, when a display or an alarm of the ash clogging is issued, the ash clogging valve 3 is opened and an impact is applied to the hopper 1. By adding the ash, the ash in the hopper 1 can be easily dropped.

[0016]

According to the ash clogging detection device of the present invention, a thermometer for detecting the presence or absence of ash clogging in the hopper is provided in an air supply pipe having a large temperature change due to ash clogging, so that ash clogging can be performed quickly. It can be detected accurately. Further, since the detected temperature is corrected with the atmospheric temperature, the fluctuation of the atmospheric temperature can be compensated to further improve the detection accuracy. As a result, ash clogging in coal boilers and the like using inexpensive fuel can be dealt with early,
The problem due to ash clogging can be advantageously solved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ashes clogging detection device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hopper 2 Ash supply valve 3 Actuator 4 Switching valve 5 Blow tank 6 Blow nozzle 7 Air supply tube 8 Ball valve 9 In-tube thermometer 10 Atmospheric thermometer 11 Judgment device 12 Display device H ash

Claims (2)

[Claims] 1. An apparatus for sending ash in flue gas into an air supply pipe by means of air ejected from a nozzle, comprising: an in-tube thermometer for detecting a temperature in the air supply pipe; and an atmospheric thermometer for detecting a temperature of the atmosphere. An ash clog detection device, further comprising: a determination unit configured to determine whether a difference between a temperature detected by the in-pipe thermometer and a temperature detected by the atmospheric thermometer exceeds a set value. 2. The ash clogging detecting device according to claim 1, wherein the in-pipe thermometer and the atmospheric thermometer are thermocouples.