JPS5974206A - Safety device for top pressure recovering device of blast furnace - Google Patents

Abstract

PURPOSE:To cool the waste gas of an abnormally high temp. owing to blow- through down to a safe temp. by detecting the waste gas temp. of a blast furnace on the upper stream side of a dry dust collector, and ejecting a cooling fluid into the pipeline between the dry dust collector and a turbine in accordance with the detected value thereof. CONSTITUTION:The waste gas from the top of a blast furnace 1 is fed through a coarse particle removing device 3 and a dry collector 4 to a turbine 9, which converts the energy stored in the waste gas by a power generator to electric energy. Two sensors 15A, 15B are provided in the pipeline 2 on the upper stream side of the collector 4 near the blast furnace 1, and a cooling fluid injector 16 is provided near the pipeline 5 between the downstream side of the collector 4 and the upper stream side of the turbine 9. The sensors 15A, 15B detect the temp. of the waste gas and input the same to a high selector 17, then the selector 17 actuates the injector 16 to eject the cooling fluid into the pipeline 5 in accordance with the higher temp. thereof so that the temp. of the waste gas is deceased down to the safe operating temp. of the turbine 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for an energy recovery device in a blast furnace for protecting the inside of a system including a turbine etc. from abnormally high temperatures of exhaust gas caused by blow-through of the blast furnace.

The exhaust gas emitted from the top of the blast furnace is at high temperature and has considerable pressure, and the amount of gas is large.
A so-called furnace top pressure energy recovery turbine (hereinafter referred to as a turbine for convenience) is used as a device for recovering and utilizing the energy contained in the furnace.

However, in a blast furnace, during operation, a part of the loading material melts and solidifies, becomes suspended in the air, and falls, causing a so-called blow-through in which a large amount of high-temperature gas is blown up at once.

Under normal operating conditions of a blast furnace, the temperature of the exhaust gas used in the turbine is lowered by a dust collector, so the temperature at the turbine inlet is usually 1.20 to 180 degrees Celsius, whereas this temperature is lower than that in the blast furnace atrium. The temperature sometimes reaches 250° C. or more, and this abnormally high temperature exhaust gas causes damage to the system including the turbine and dust collector.

On the other hand, various types of dust collectors are used for high-temperature exhaust gas, and various types of dry-type dust collectors are widely used because they are advantageous in that the exhaust gas temperature does not drop much. Even if a dust collector is used that can withstand the high-temperature exhaust gas of the blast furnace, there is a problem that other parts of the system, including the turbine, cannot withstand the high temperatures of the blast furnace.

Therefore, in the present invention, in an energy recovery device for blast furnaces, the blast furnace atrium is designed to protect the inside of the system, including the turbine, from high-temperature exhaust gas.

That is, the safety device of the blast furnace three energy recovery device of the present invention includes three blast furnaces in which a blast furnace, a coarse dust remover, a dry dust collector, and a furnace top pressure energy recovery turbine are arranged in this order via a pipe line. In the energy recovery device, a plurality of humidity sensors that detect the temperature of the exhaust gas from the blast furnace are installed in the pipe line upstream from the dry dust collector, and the humidity sensor detects the temperature of the exhaust gas from the blast furnace based on the higher temperature of each signal from these temperature sensors. A cooling fluid injection device capable of injecting cooling fluid into a conduit between the dry precipitator and the top pressure energy recovery turbine is provided.

An embodiment of the present invention will be described below with reference to the drawings, which are system diagrams of three blast furnace energy recovery devices in the embodiment.

First, exhaust gas discharged from the top of the blast furnace 1 passes through a pipe 2 to a coarse dust remover 6 such as a dust catcher, and after large-sized dust is removed, it is transferred to an electrostatic precipitator or cyclone. , the exhaust gas is sent to a dry dust collector 4 such as a bag filter, where it collects dust.Next, the exhaust gas reaches a pipe 5, passes through a stop valve 6, an emergency shutoff valve 7, and a speed regulating valve 8, and is then sent to a turbine 9. The energy of the exhaust gas is converted into electrical energy by the generator 10, and the exhaust gas leaving the turbine 9 is passed from the pipe 11 to the pipe 16.
It is then discharged from the system.

Further, a bypass pipe 12 is provided that connects the downstream side of the dry precipitator 4 and the pipe 16 downstream of the -pin 9. A septum valve 14 is provided to control the flow rate.

Therefore, in this embodiment, two or more temperature sensors 15A, 15B are arranged in the pipe line 2 on the upstream side of the dry dust collector 4 at a position close to the blast furnace 1, and the temperature sensors 15A , 15B detects the exhaust gas temperature from the blast furnace 1 and sends these signals to the high selector 17, and the high selector 17 starts dry dust collection using a cooling fluid based on the higher humidity of the signals. A cooling fluid injection device 16 for injecting fluid into the pipe line 5 between the downstream side of the turbine 4 and the upstream side of the turbine 9 is disposed near the pipe line 5.

In the safety device of the blast furnace three energy recovery device of the present invention having the above-mentioned configuration, the atrium of the blast furnace 1 sometimes immediately detects the temperature of the high-temperature atrium using the temperature sensors 15A and 15B, and detects the temperature of the higher one. Based on this, the cooling fluid from the cooling fluid injection device 16 is sent to the dry precipitator 4 and the turbine 9.
to reduce the exhaust gas temperature to the safe operating temperature of the turbine 9.

Further, when all of the temperature sensors 15A and 15B detect that the temperature of the exhaust gas from the blast furnace 1 has returned to the normal state, the operation of the cooling fluid injection device 16 is stopped.

In addition, as described above, a plurality of temperature sensors 15 are provided.
A and 15B are provided in the pipe line 2 on the upstream side of the dry dust collector 4, but as in this embodiment, it is better to provide them at a position closer to the blast furnace 1 in order to provide more time for the operation of the cooling fluid injection device 16. Desirably, the cooling fluid injection device 16 may be provided near the downstream side of the dry dust collector 4 as in this embodiment, but it may also be provided in any part of the pipe line 5 to the turbine 9.

Therefore, the safety device of the present invention is extremely effective in safely protecting the inside of the turbine and other systems in the blast furnace atrium in the blast furnace energy recovery device.

In particular, in the present invention, since a plurality of temperature sensors are arranged on the upstream side of the dry collector, the reliability of wetness detection can be improved compared to the case where one temperature sensor is arranged. At the same time, even when the temperature detected by the temperature sensor of the exhaust gas at the top outlet of the blast furnace returns to normal temperature, the high temperature exhaust gas from the blast furnace remains in the pipe between the temperature sensor and the turbine. If there is, it can be detected by another temperature sensor and these high-temperature exhaust gases can be cooled by the cooling fluid injection device, which has the advantage of being highly reliable as a safety device for turbines and the like.

The present invention can be effectively applied mainly as a safety device for an energy recovery device for blast furnaces having a dry dust collector that does not require cooling the atrium of the blast furnace.

[Brief explanation of the drawing]

The drawing is a system diagram of three energy recovery devices for blast furnaces in one embodiment of the present invention. 1...Blast furnace, 2...Pipe line, 6...Coarse dust remover, 4
...Dry type dust collector, 5...Pipe line, 6...Turbine,
15A. 15B... Temperature sensor, 16... Cooling fluid injection device, 17... High selector.

Claims (1)

[Claims] In three energy recovery devices for blast furnaces, which are arranged in the order of blast furnace, coarse dust remover, dry dust collector, and furnace top pressure energy recovery turbine via pipelines, a temperature sensor is installed to detect the temperature of the exhaust gas from the blast furnace. , a plurality of them are arranged in the pipe line upstream from the dry type precipitator, and based on the higher temperature of each signal from these temperature sensors, the cooling fluid is connected to the dry type precipitator and the furnace top pressure energy. 1. A safety device for an energy recovery device for blast furnaces, characterized in that a cooling fluid injection device capable of injecting cooling fluid is disposed in a conduit between the recovery turbine and the recovery turbine.