JPS5974207A - Safety device of top pressure energy recovering device of blast furnace - Google Patents

Abstract

PURPOSE:To decrease the temp. of the waste gas of an abnormally high temp. by blow-through down to a safe temp. by detecting the temp. of the waste gas in a blast furnace on the upper stream side of a dry cust collector and ejecting a cooling fluid from plural places of the pipeline on the upper stream side of the dry dust collector in accordance with the detected value. CONSTITUTION:The waste gas from the top of a blast furnace 1 is fed through a coarse particle removing device 3 and a dry dust collector 4 to a turbine 9 which converts the energy stored in the waste gas by a power generator 10 to electric energy. A temp. sensor 15 is disposed in the pipeline 2 on the upper stream side of the collector 4 near the blast furnace 1. Two cooling fluid injectors 16A, 16B are disposed wit the device 3 in-between in the pipeline 2 on the upper stream side of the collector 4. The cooling fluid is ejected from the injectors 16A, 16B in accordance with the temp. detected with the sensor 15, by which the temp. of the waste gas is decreased down to a safe temp. The cooling fluid of the amt. conforming to the temp. of the waste gas is ejected successively from the injectors 16A, 16B, so that the recovering device system is protected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for an energy recovery device for blast furnaces, which protects the inside of a system including a dry precipitator from abnormally high temperatures of exhaust gas caused by blast furnace blow-through.

The exhaust gas that comes out from the top of the blast furnace is at high temperature and has considerable pressure, and the amount of gas is large. Therefore, a so-called top pressure energy recovery turbine is used as a device to recover and utilize the energy contained in this exhaust gas. (hereinafter referred to as a turbine for convenience) is used.

However, in a blast furnace, during operation, a part of the loading material melts and solidifies, becomes suspended in the air, and then 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 120 to 180 degrees Celsius. The temperature exceeds 250°C, and this abnormally high temperature exhaust gas causes damage to the system including the turbine and dust collector.

On the other hand, as a dust collection method for the exhaust gas supplied to the turbine of such blast furnace energy recovery equipment, a dry dust collector that collects dust using a dust catcher, cyclone bag filter, etc. is used to reduce the exhaust gas temperature. Although it is widely known that such dry dust collectors are advantageous in that they have less dust, they are generally not suitable for high temperatures, and there is a problem that blast furnace vents cannot withstand the high temperatures that occur.

Accordingly, the present invention provides an energy recovery device for three blast furnaces using a dry dust collector, in which the blast furnace atrium is designed to protect the inside of the system during times.

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 temperature sensor that detects the temperature of the exhaust gas from the blast furnace is installed in the pipe line upstream of the dry dust collector, and a signal from this temperature sensor is used to direct the cooling fluid to the upstream side of the dry dust collector. The system is constructed by disposing cooling fluid injection devices capable of injecting liquid at a plurality of locations in the pipe line.

An embodiment of the present invention will be described below with reference to the drawings.
The drawing is a system diagram of three blast furnace energy recovery devices in the embodiment.

First, the exhaust gas discharged from the top of the blast furnace 1 passes through the pipe 2 and reaches a coarse dust remover 6 such as a dust catcher. The dust is sent to a dry dust collector 4 such as a filter, and collected there.

Next, the exhaust gas reaches the pipe 5, passes through the stop valve 6, the emergency shutoff valve 7, and the regulating valve 8, and is sent to the turbine 9. The energy of the exhaust gas is converted into electrical energy by the generator 1°, and the turbine The exhaust gas exiting from 9 is passed from pipe 11 to pipe 13.
It is then discharged from the system.

Furthermore, a bypass pipe 12 is provided that connects the downstream side of the dry precipitator 4 and the pipe 13 on the downstream side of the turbine 9. A controlling septum valve 14 is provided.

Therefore, in this embodiment, a temperature sensor 15 is disposed in a position close to the blast furnace 1 in the pipe line 2 on the upstream side of the dry dust collector 4, and the temperature sensor 15 detects the temperature of the exhaust gas from the blast furnace 1. , when the temperature is higher than a predetermined temperature, a signal is issued to direct the cooling fluid to the pipe line 2 on the upstream side of the dry precipitator 4.
Two cooling fluid injection devices 16A and 16B are respectively disposed before and after the coarse particle dust remover 6 in the pipe line 2 so as to inject the cooling fluid at a plurality of locations, for example, two locations as in this embodiment.

In the safety device of the blast furnace three energy recovery device of the present invention having the above configuration, the blast furnace 1 sometimes immediately detects the high temperature exhaust gas temperature by the temperature sensor 15, and cools the blast furnace 1 from the cooling fluid injection devices 16A and 16B. conduit 2
The exhaust gas temperature is injected into the interior to lower the exhaust gas temperature to a safe temperature.

Further, when the temperature sensor 15 detects that the exhaust gas temperature from the blast furnace 1 has returned to the normal temperature, the operation of the cooling fluid injection devices 16A and 16B is stopped.

The temperature sensor 15 is installed in the pipe line 2 upstream of the dry dust collector 4, but as in this embodiment, it is better to install it closer to the blast furnace 1 than the cooling fluid injection devices 16A and 16.
The cooling fluid injection device 16A is desirable in order to provide a margin for the operation time of the cooling fluid injection device 16A.

and 16B are arranged at appropriate intervals in the pipe line 2, and in response to a signal from the temperature sensor 15 that detects a sudden rise in exhaust gas temperature due to the blow-through of the blast furnace 1, an amount of cooling fluid commensurate with the temperature rise is sent to the upstream side. The cooling fluid is injected sequentially from the cooling fluid injection device 16A and then from the downstream side 16B. Also, when the temperature of the atrium of the blast furnace 1 decreases after returning from the state to the normal state, the cooling fluid injection device 16A1 on the upstream side and the cooling fluid injection device 16 on the downstream side are injected sequentially.
The operation is stopped in sequence with B.

As a result, the exhaust gas can be cooled in proportion to the temperature rise and fall of the exhaust gas.

Therefore, the safety device of the present invention provides that the blast furnace atrium in the three energy recovery devices using a dry dust collector is sometimes
It is extremely effective in safely protecting the inside of the system, including the dry precipitator and turbine.

In addition, in the present invention, the blow-through from the blast furnace is detected by temperature on the upstream side of the dry type dust collector, and cooling is performed on the upstream side, so it is possible to prevent delays in temperature detection, and This has the advantage that the inside of the system can be reliably protected and the turbine side is not affected.

In particular, in the present invention, two or more cooling fluid injection devices are provided, which enables highly accurate temperature control commensurate with the temperature rise and fall of the exhaust gas, and the temperature of the exhaust gas flowing into the dry precipitator. can be kept almost constant at all times, so
The reliability of the blast furnace three energy recovery devices as a safety device is extremely high.

[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...Pipeline, 6...Coarse dust remover, 4
...Dry dust collector, 5...Pipe line, 6...Turbine,
15... Temperature sensor, 16A, 16B... Cooling fluid injection device.

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 cooling fluid injection device is installed in the pipe line upstream of the dry dust collector, and is capable of injecting cooling fluid to a plurality of locations in the pipe line upstream of the dry dust collector based on a signal from the temperature sensor. A safety device for three energy recovery devices in blast furnaces, which is characterized by the following: