JP2505869B2 - Method for detecting blockage of slag outlet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for detecting blockage of a slag flow port in a cyclone combustion furnace that combusts pulverized coal, char, sludge, etc., especially in a pressurized cyclone combustion furnace. It is about.

[Prior Art] Fine powder, which is put into a cyclone combustion furnace together with combustion air from a tangential direction of a cylindrical cross section of the combustion furnace, or is given from the axial direction of the combustion furnace while being swirled by a swirler or the like. Fuel such as coal crushed into high temperature
It burns while swirling in an atmosphere of high heat load, and most of the combustion ash is melted and made to flow down along the inner peripheral wall of the combustion furnace, and it is arranged below the slag flow port formed at the bottom of the combustion furnace. Pour it into the slag tank. Slag cooling water is injected into the slag tank, and the slag flowing down into the slag cooling water is cooled and solidified, and then carried out of the slag tank by a drag chain conveyor or the like. While the temperature inside the combustion furnace is maintained at a high enough temperature to melt the slag, the inside of the slag tank at the bottom of the slag outlet is relatively cold, so the molten slag flowing down from the slag outlet is Part of it cools and solidifies.
During the operation of the combustion furnace for a long period of time, the cooling and solidification of the molten slag gradually progress, and finally the slag flow port may be blocked by the solidified slag.

Conventionally, as a means for detecting and preventing the blockage of the slag flow port, a slug is installed above or below the slag flow port, and after visually confirming that the slag flow port is blocked. , Or after confirming that the amount of cooled and solidified slag discharged from the slag tank decreases, or regardless of the blockage of the slag flow port, the slag slag penetrates into the slag flow port at regular intervals. By doing so, blockage of the slag flow port was prevented.

[Problems to be Solved by the Invention] As described above, also in the above-described conventional technique, the slag flow-out port formed in the bottom of the combustion furnace is closed by the cooled and solidified slag, and the molten slag in the combustion furnace accordingly. Is 2
It was possible to prevent the situation such as flowing into the next furnace and to operate the combustion furnace safely and continuously. However, in the above-mentioned conventional technology, it is not always possible to cope with the case where the state inside the combustion furnace changes abruptly due to a change in load, a change in fuel, etc., and the blockage of the slag downstream rapidly progresses, or labor, power, etc. There was a problem such as a large loss.

[Means for Solving the Problem] A means for solving the above problem is the method for detecting blockage of the slag downflow port described in the first and second claims. That is, 1. An optical sensor is provided on the downstream side of the slag flow-outlet in the cyclone combustion furnace, the light amount at the slag flow-outlet is measured, and the slag flow-down that detects whether or not the slag flow-out port is blocked based on the measurement result Mouth blockage detection method.

2. Measure the differential pressure between the internal pressure of the cyclone combustion furnace and the gas pressure in the slag tank that is placed downstream of the slag flow port and into which the sealing air is fed, and based on the change in the differential pressure, the slag flow port A method for detecting blockage of a slag flow outlet that detects the presence or absence of blockage.

Hereinafter, the operation and the like of the present invention will be described based on Examples.

[Embodiment] FIGS. 1 to 3 show an embodiment based on the present invention. FIG. 1 shows combustion of fuel such as coal pulverized into fine powder to form combustion ash in a molten state at the bottom of a combustion furnace. Partly cutaway perspective view of the cyclone combustion furnace that is made to flow down from the installed slag downflow port. Figure 2 shows the light in the flow path that connects the slag downflow port formed at the bottom of the combustion furnace and the slag tank installed at the bottom. FIG. 3 is a vertical cross-sectional view of the vicinity of the slag flow port when the sensor is installed, and FIG. 3 is a vertical cross-sectional view of the vicinity of the slag flow port when the detectors of the combustion furnace internal pressure and the slag tank internal pressure are installed. In FIGS. 1 to 3, 1 is a cyclone combustion furnace, 2 is a fuel and combustion air inlet, 3 is a slag downflow port, 4 is a secondary furnace, 5 is a slag tank, 6 is an optical sensor, 7 is a pressure detection inside the furnace. Reference numeral 8 denotes a tank internal pressure detector. In FIGS. 1 to 3, the fuel and the combustion air input port 2 installed on the upstream upper side of the cyclone combustion furnace 1 are pulverized into fine powdery pulverized coal, etc., which are injected in the tangential direction of the cylindrical cross section of the combustion furnace 1. Fuel and combustion air
Under the atmosphere of high temperature and high heat load in the combustion furnace 1,
It burns while swirling along the inner peripheral wall of the slag, and most of the combustion ash (80 to 90%) becomes a molten state and flows down to the furnace bottom along the peripheral wall, and the slag outlet formed in the furnace bottom. 3 flows into the slag tank 5 arranged below the flow-down port 3. The slag tank 5 has a double structure as shown in FIGS. 2 and 3, and water is injected into the slag tank 5 to cool and solidify the molten ash (hereinafter referred to as slag) in a molten state flowing down. The inside of the combustion furnace 1 and the outside air are water-tightly closed to prevent leakage of combustion gas to the outside or invasion of the atmosphere into the furnace. The molten slag flowing down into the water in the slag tank 5 is immediately cooled and solidified, and is carried out from the bottom of the slag tank 5 to the outside by a drag chain conveyor or the like. While the temperature in the combustion furnace 1 is maintained at a high temperature sufficient to melt the slag, the inside of the slag tank 5 arranged below the slag downflow port 3 is always filled with water to a certain level. Since the temperature of the molten slag is relatively low due to the fact that the molten slag flows down from the slag downflow port 3, part of the molten slag flows down through the downflow port 3
May cool and solidify in the vicinity of the outlet. While the combustion furnace 1 is operated for a long time, the cooling and solidification of the molten slag gradually progress, and finally the slag flow-down port 3 is blocked by the solidified slag, and the operation of the combustion furnace 1 cannot be continued. May be

The present invention has been made to solve the above problems. FIG. 2 shows the first embodiment, and in the flow path connecting the slag flow-down port 3 and the slag tank 5, in a direction in which the amount of light around the lower part of the slag flow-down port 3 part can be measured from the outside air side, The optical sensor 6 is installed. While the combustion furnace 1 is operated for a long time, cooling and solidification of the slag in the slag flow-down port 3 part proceed, and the opening area of the slag flow-down port 3 decreases, so that the light amount measured by the optical sensor 6 also gradually decreases. However, as the slag downflow port 3 approaches a completely closed state, the light amount measured by the optical sensor 6 sharply decreases. When the slag downflow port 6 is completely closed, heat radiation from the inside of the combustion furnace 1 to the lower part of the slag downflow port 6 or convection of high-temperature combustion gas is blocked, thereby closing the slag downflow port 6 part. The slag that forms is rapidly solidified to increase its strength, and it becomes difficult to remove the slag adhering to the slag downflow port 3 part by slag lance. Therefore, when the amount of light measured by the optical sensor 6 falls below a predetermined value, the slag lance is immediately actuated by a manual operation or automatically to cause the slag lance to penetrate into the slag downflow port 3 and soften. The adhered slag having various properties is separated from the slag flow-down port 3 and dropped into the slag tank 5.

FIG. 3 shows a second embodiment, in which a furnace pressure detector 7 for detecting the pressure in the combustion furnace 1 and a gas pressure in the slag tank 5 arranged below the slag flow-down port 3 are detected. The tank internal pressure detector 8 is attached. When the slag downflow port 3 is sufficiently open, the furnace pressure and the tank pressure are:
Although the values are almost equal to each other, during the long-time operation of the cyclone combustion furnace 1, the slag downflow port 3 is cooled and solidified through the same process as described in the first embodiment. When it is blocked by continuing, the heat radiation from the combustion furnace 1 and the convection of the high temperature combustion gas are blocked in the slag tank 5, and the gas temperature decreases due to contact with the water in the slag tank 5, Although the gas pressure initially drops accordingly, the sealing air having a pressure higher than the pressure in the cyclone combustion furnace 1 always flows into the slag tank 5, so that the slag tank 5 will eventually have a higher pressure. The pressure is slightly higher than the pressure inside the cyclone combustion furnace 1. Therefore, the differential pressure between the pressure in the furnace and the pressure in the tank is detected, and when the differential pressure reaches a predetermined value or more, the slag slag is actuated by immediately or manually operating the slug. The adhering slag is peeled off from the slag flow-down port 3 part in a state before being penetrated into the flow-down port 3 part and solidified, and dropped into the slag tank 5.

[Effects of the Invention] Since the present invention is configured as described above, it has the effects described below.

That is, the conventional slag downflow port can be visually inspected directly, or the amount of cooling slag discharged from the slag tank can be viewed to detect blockage of the slag downflow port, and the slag lance is activated, or the slag downflow port can be operated. While the slag lance was actuated to prevent the blockage regardless of the blockage condition, the present invention, as shown in the first or second embodiment, automatically, quickly and accurately by the measuring instrument. Since it became possible to obtain information on the blockage of the slag flow port, it is possible to prevent the slag flow port from being blocked by the completely hardened slag even when there is a change in the load or a sudden change in the fuel properties. In addition to preventing the above, it is possible to automatically and effectively prevent the slag flow port from being blocked by inputting the measured value into the slug drive device. A.

[Brief description of drawings]

1 to 3 show an embodiment based on the present invention.
Figure is a partially broken perspective view of the cyclone combustion furnace. Figure 2 is a vertical cross-sectional view of the vicinity of the slag flow port when an optical sensor is installed on the lower side wall of the slag flow port. Figure 3 is the combustion furnace internal pressure and slag tank. It is a longitudinal cross-sectional view of the vicinity of the slag downflow port when an internal pressure detector is installed. 1 ... Cyclone combustion furnace, 2 ... Fuel and combustion air input port, 3 ... Slag downflow port, 4 ... Secondary furnace, 5 ... Slag tank, 6 ... Optical sensor, 7 ... Reactor pressure detection Bowl, 8
…… Tank pressure detector.

Claims (2)

(57) [Claims] 1. An optical sensor is provided on the downstream side of a slag downflow port in a cyclone combustion furnace to measure the amount of light at the slag downflow port, and to detect whether or not the slag downflow port is blocked based on the measurement result. A method for detecting blockage of a slag flow outlet, which is characterized by: 2. The differential pressure between the internal pressure of the cyclone combustion furnace and the internal gas pressure of the slag tank, which is disposed downstream of the slag flow port and into which sealing air is fed, is measured, and the slag is changed based on the change in the differential pressure. A method for detecting blockage of a slag flow-out port, which comprises detecting whether or not the flow-out port is blocked.