JPS6017564B2 - How to avoid temperature control malfunction of dry dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for avoiding temperature control malfunctions in temperature control at the time of abnormality in a blast furnace when a dry dust collector is used.

In general, dry dust collectors do not pass through high temperatures, and when used in energy recovery turbine equipment that uses blast furnace gas, they cannot withstand the excessive rise in gas temperature caused by abnormalities such as blast furnace blow-through or slippage. It is.

For this reason, it is essential to have a device that controls the temperature by injecting cooling water into the blast furnace gas passage, but as is well known, temperature detection has problems with accuracy and detection time delay, The types of thermometers that can be used for this purpose are limited; for example, a sheathed thermocouple or the like must be used, and a protective tube must be omitted in order to avoid a delay in detection. However, when a temperature detection method that does not include a protective tube is used, it is susceptible to the effects of static electricity, etc., and as a result, the generated current value increases, and as a result, the detected temperature value may show a value that is larger than the actual value.
When water fog control is performed based on the detected temperature value,
The moisture content of the blast furnace gas increases and eventually reaches a supersaturated state. If a dry bonito collector using a bag (furnace cloth) is used as a dust collector, the oven cloth will cause vomiting due to oversaturation of moisture, which will have a fatal effect on subsequent use. Therefore, if you use a thermometer without a protective tube,
Measures are needed to avoid such malfunctions. The present invention is intended to solve this problem, and a thermoelectric thermometer equipped with a protective tube is provided in the gas passage leading to the dry dust collector, and the dry dust collector protects the clean gas passage fed to the furnace. A dry dust collector equipped with a thermoelectric thermometer without a protective tube, and constantly checking the temperature detected by the thermoelectric thermometer without a protective tube with the temperature detected by the thermoelectric thermometer with a protective tube. This provides a method for avoiding temperature control malfunctions.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, blast furnace gas discharged from the top of a blast furnace 1 passes through a coarse dust collector 2 and a dry dust collector 3, and is guided from a septum valve 4 to a gas holder 6. Reference numeral 6 denotes a power generation facility installed in parallel with the septum valve 4, which is connected to the in-house power grid and takes the load.The energy recovery turbine 8 that drives the generator 7 is connected to the blast furnace from the inlet side of the septum valve 4. Gas is introduced and driven.

In this case, the septum valve 4 is closed and the furnace top pressure is appropriately adjusted on the turbine side and kept constant. The blast furnace gas that has driven the energy recovery turbine 8 is returned to the output side of the septum valve 4. Further, the coarse particle dust collector 2 is provided with a cooling fluid injector 9, and a cooling fluid is sprayed through an electric valve 10. Reference numeral 11 denotes a normal type thermocouple thermometer equipped with a protective tube, which is installed in a gas passage leading to the dry dust collector 3, for example, between the blast furnace 1 and the coarse dust collector 2. Although it involves errors and detection time delays, it is a type of thermometer that is not affected by static electricity.

Reference numeral 12 is a sheathed thermocouple thermometer installed in the path of the clean gas filtered by the dry dust collection bag hawk 3, which directly detects the gas temperature without using a protective tube, and is highly sensitive and accurate. , susceptible to static electricity, etc.

In the case of the bag-type dry dust collector 3, the important factors in temperature control using the thermometers 11 and 12 are to keep the heat-resistant temperature of the furnace cloth below, for example, 21 pi or less, and to keep the temperature at a temperature of, for example, 1.5 k9.
The temperature does not reach 70° C. for ground gas, and the control device 13 takes into account the temperature detection values of the thermometers 11 and 12 and controls the electric valve 10 to maintain the temperature within the above temperature range, for example. For example, the thermocouple thermometer 11 on the exit side of the blast furnace 1 forms a feedforward control system in the event of an abnormality such as blast furnace blow-through or slip, and the sheathed thermocouple thermometer 12 on the exit side of the dry dust collector 3 provides feedback during normal times. Form a control system. Now, let T be the temperature detection value of the thermocouple thermometer 11 on the exit side of the blast furnace 1, and let L be the temperature detection value of the sheathed thermocouple thermometer 12 on the exit side of the dry dust collector 3. At a detected temperature value T, below a certain set value that does not reach the temperature of , the calculated value (T, /T2) or (T2
/T, ), T, /T2《1.0 or L/T
, >> When the value is 1.0, it can be determined that the detected temperature value 2 has a large error toward the higher temperature side than the actual value, and this may be due to the influence of static electricity due to the omission of the protective tube. Also T,/
T2》1.0 or L/T,《0.1. In this case, it can be determined that the temperature detection value port 2 has a large error toward the lower temperature side than the actual value, and a failure such as disconnection of the electrostatic couple due to the omission of the protective tube is considered.

Therefore, in the control device 13, a computing unit 1 as shown in FIG.
4, 15, and T. <Setting value T, /T2《If 1.0 or T. <T, /T2 at the set value> In the case of 1.0, a motorized valve closing signal is generated to either stop the fluid misting by the motorized valve 10 or prevent the fluid misting operation.

This makes it possible to avoid temperature control malfunctions that may occur due to the use of the sheathed thermocouple thermometer 12 without the protective tube. Note that the calculated value based on the temperature detection value T,, T2 is not limited to (T, T2) or (T2/T,),
A calculated value of (T, 10T2) or (T, 1T2) may be adopted. In addition, the number of thermoelectric types that exclude the protective tube provided in the dry type dust collector is not limited to one, but if the dry type dust collector is formed of a plurality of bag elements 16 as shown in FIG. A total of three thermometers 20, 21, 22 may be provided in the two clean gas branch passages 17, 18 to which the 16 groups of bag elements are connected, and in the clean gas main passage 19 where these are integrated. , in this case, the maximum temperature detection value T2', T2''.T2''' obtained from this is used in the control device 13.

As described above, according to the present invention, the temperature detection value of the first thermoelectric thermometer equipped with a protective tube provided in the blast furnace gas passage leading to the dry dust collector and the clean gas filtered by the dry dust collector A predetermined calculation value is calculated from the temperature detection value of a second thermoelectric thermometer provided in the passage without a protective tube, and when the calculation value does not satisfy a predetermined limit value, the fluid spray is stopped or not operated. Since the control of Not only is it possible to avoid temperature control malfunctions due to false detections, which can easily occur by eliminating the protective tube,
Its industrial value is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a system diagram for explaining temperature control of a dry dust collector, Fig. 2 is a block diagram of main parts showing an embodiment of the present invention,
FIG. 3 is a configuration diagram showing another arrangement of the thermometer fin type thermometer on the exit side of the dry dust collector. 1... Blast furnace, 2... Coarse particle collection machine counterfeit, 3
...Dry dust collector, 9...Cooling fluid injector, 10...Electric valve, 11...Thermocouple thermometer (1
thermocouple thermometer), 12... sheathed thermocouple thermometer (
second thermoelectric thermometer), 13...control device, 1
4, 15... Arithmetic unit. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. The first thermoelectric thermometer equipped with a protective tube was installed in the blast furnace gas passage leading to the dry dust collector, and the protective tube installed in the clean gas passage filtered by the dry dust collector was omitted. A predetermined set value of the temperature detection value of the first thermoelectric thermometer when performing temperature control using the second thermoelectric thermometer to lower the gas temperature by liquid spray when the blast furnace gas reaches an abnormally high temperature. In the following, a predetermined calculated value is taken from the temperature detection values of the first and second thermoelectric thermometers, and when the calculated value does not satisfy a predetermined limit value, the fluid spray is stopped or not operated. Features: A method for avoiding temperature control malfunctions in dry dust collectors.