A high-temperature protection control method for a blast furnace dry dedusting cloth bag

Abstract

The present application relates to the technical field of metallurgical equipment manufacturing, and particularly relates to a high-temperature protection control method for a bag filter of a blast furnace dry dedusting system, which can promote safe and stable operation of the blast furnace dry dedusting system and effectively prolong the service life of the dry bag filter.

Description

[Technical Field]

[0001] This invention belongs to the field of metallurgical equipment manufacturing technology, and specifically relates to a method for high-temperature protection and control of dry dust collector bags for blast furnaces. [Background Technology]

[0002] Dry dust collector bags for blast furnaces are used to purify and remove dust from high-temperature blast furnace gas. The operating temperature of these bags must be below 300℃. Prolonged operation at temperatures above 300℃ will reduce the lifespan of the bags and may even cause damage. Currently, when the blast furnace gas temperature is excessively high, the main method of protection is to manually close some of the inlet and outlet butterfly valves of the dry dust collector bag housing. However, this method has the following drawbacks:

[0003] 1. Failure to detect excessively high blast furnace gas temperature in a timely manner resulted in delayed closure of the inlet and outlet butterfly valves of the dry process box, and even instances of neglecting high temperature alarm signals and failing to take protective measures.

[0004] 2. The process of manually closing the inlet and outlet butterfly valves of the dry filter bag one by one takes a long time and still causes some damage to the filter bag.

[0005] 3. The inability to quickly select the latest replacement bag for protection reduces the lifespan of the bag.

[0006] Based on this, the present invention proposes a high-temperature protection control method for dry dust collector bags in blast furnaces. [Summary of the Invention]

[0007] In view of the above, it is necessary to provide a high-temperature protection control method for dry dust collector bags in blast furnaces. This method can promote the safe and stable operation of dry dust collector systems in blast furnaces and effectively extend the service life of dry dust collector bags.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A method for high-temperature protection and control of dry dust collector bags in blast furnaces, the method comprising the following steps:

[0010] (1) Setting up a control system: The control system includes a blast furnace, a gravity dust collector, and a dry dust collector bag box connected in sequence by pipelines. The blast furnace is equipped with a first temperature detection element and a pressure detection element. There are several dry dust collector bag boxes. A second temperature detection element, an inlet butterfly valve, and an inlet gate valve are sequentially installed on the pipeline connecting the gravity dust collector and each dry dust collector bag box. The second temperature detection element, the inlet butterfly valve, and the inlet gate valve are all located on the inlet pipeline of the dry dust collector bag box. An outlet gate valve and an outlet butterfly valve are installed on the outlet pipeline of the dry dust collector bag box. The control system also includes a controller and an alarm device. The alarm device, the first temperature detection element, the second temperature detection element, and the pressure detection element are all electrically connected to the controller.

[0011] (2) High temperature protection:

[0012] A. Closing the first N dry dust collector bag boxes: When the first or second temperature detection element detects a temperature value greater than the set value, and the pressure detection element detects a pressure value greater than the set value, the alarm device is activated. After 5 seconds of alarm, the high-temperature protection control program is activated, specifically: automatically and quickly closing the inlet and outlet butterfly valves of the first N dry dust collector bag boxes in a pre-set sequence. The value of N is determined based on the minimum number of bags K corresponding to the required cold air flow rate Qmax during blast furnace full-air production; N = total number of dry dust collector bag boxes - K; K ≤ N;

[0013] B. Closing the dry dust collector bag boxes after sequence N: The high temperature protection control program is activated. After closing the inlet and outlet butterfly valves of the first N dry dust collector bag boxes, if the temperature value detected by the first or second temperature detection element still exceeds the set value, the inlet and outlet butterfly valves of the dry dust collector bag boxes after sequence N will be automatically closed gradually according to the decreasing rate of the blast furnace cold air flow Q.

[0014] (3) Resumption of use: When the first temperature detection element and the second temperature detection element detect a temperature value less than or equal to the set value, an alarm is issued saying "Gas temperature drops, please put the box into use in time". At this time, the operator shall restore the dry dust collector bag box into use in time according to the blast furnace production situation.

[0015] In this invention, further, in step (2), the number of the first temperature detection elements is four, and the detected temperature value is the average of the four detection values.

[0016] In this invention, further, the number of dry dust collector bag boxes in step (1) is 14.

[0017] In this invention, the pre-set sorting of dry dust collector bag boxes in step (2) is determined according to the order in which the bags are put into use, with the most recently put bag box being sorted as 1, and so on.

[0018] In this invention, further, in steps (2) and (3), the set value of the temperature detected by the first temperature detection element is 600°C, the set value of the temperature detected by the second temperature detection element is 350°C, and the set value of the pressure detection element is 50 kPa.

[0019] Furthermore, this invention also includes an instrument detection step, specifically: before executing the high-temperature protection control program, it is first determined whether the instrument detection is normal. When the instrument detection is normal, the high-temperature protection control program is effective; when the instrument detection is abnormal, the high-temperature protection control program is ineffective.

[0020] The present invention has the following beneficial effects:

[0021] This invention combines processing systems and control methods to quickly and automatically shut down part of the dry dust collector bag housing for protection when the blast furnace gas temperature is too high. This reduces the number of bags burned, promotes the safe and stable operation of the blast furnace dry bag dust collection system, effectively extends the service life of the dry bags, and has a high degree of automation, making it worthy of promotion in actual production. [Attached Image Description]

[0022] Figure 1 This is a schematic diagram of the dry dust removal system for blast furnaces according to an embodiment of the present invention;

[0023] In the figure, the reference numerals are: 1. Blast furnace; 2. Gravity dust collector; 3. Dry dust collector bag housing; 4. First temperature detection element; 5. Pressure detection element; 6. Second temperature detection element; 7. Inlet butterfly valve; 8. Inlet slide gate valve; 9. Outlet slide gate valve; 10. Outlet butterfly valve.

[0024] Figure 2 This is a schematic diagram illustrating the high-temperature protection control principle of the dry dust collector bag in a blast furnace according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram illustrating the exit principle of the high-temperature protection control program for the dry dust collector bag in a blast furnace according to an embodiment of the present invention.

Detailed Implementation Methods

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Example

[0028] This embodiment provides a method for high-temperature protection and control of dry dust collector bags in blast furnaces, the method comprising the following steps:

[0029] (1) Set up a control system: such as Figure 1 As shown, the control system includes a blast furnace 1, a gravity dust collector 2, and a dry dust collector baghouse 3 connected in sequence by pipelines. The blast furnace 1 is equipped with a first temperature detection element 4 and a pressure detection element 5. There are several dry dust collector baghouses 3. A second temperature detection element 6, an inlet butterfly valve 7, and an inlet gate valve 8 are sequentially installed on the pipeline connecting the gravity dust collector 2 and each dry dust collector baghouse 3. The second temperature detection element 6, the inlet butterfly valve 7, and the inlet gate valve 8 are all located on the inlet pipeline of the dry dust collector baghouse 3. An outlet gate valve 9 and an outlet butterfly valve 10 are installed on the outlet pipeline of the dry dust collector baghouse 3. The system also includes a controller and an alarm device. The alarm device, the first temperature detection element 4, the second temperature detection element 6, and the pressure detection element 5 are all electrically connected to the controller.

[0030] Specifically, firstly, set values ​​are input to the first temperature sensing element 4, the second temperature sensing element 6, and the pressure sensing element 5. Then, the temperature and pressure are measured, and the measured information is transmitted to the controller. The controller compares the received temperature / pressure information with the internally stored values ​​to determine whether the temperature / pressure has reached the set value. When the first temperature sensing element 4 or the second temperature sensing element 6 detects that the temperature value is greater than the set value, and the pressure sensing element 5 detects that the pressure value is greater than the set value, the controller controls the alarm device to sound an alarm; (the controller and alarm device are not shown in the figure).

[0031] (2) High temperature protection (control principle as follows) Figure 2 As shown):

[0032] A. Closing the first N dry dust collector bag boxes 3: When the first temperature detection element 4 or the second temperature detection element 6 detects a temperature value greater than the set value, and the pressure detection element 5 detects a pressure value greater than the set value, the alarm device is activated, emitting an alarm sound of "gas temperature too high". After 5 seconds of alarm, the high temperature protection control program is activated, specifically: automatically and quickly closing the inlet butterfly valve 7 and outlet butterfly valve 10 of the first N dry dust collector bag boxes 3 in a pre-set order. The pre-set order of the dry dust collector bags is determined according to the order in which the bags are put into use, with the most recently put bag box being number 1, and so on; the value of N is based on the cold air flow rate Qm required during full-air production of the blast furnace. The minimum number of boxes K corresponding to ax is determined; N = total number of dry dust collector bag boxes 3 - K; K ≤ N; (For example, there are 14 dry dust collector bag boxes, and the minimum number of boxes K corresponding to the cold air flow rate Qmax required for full blast production in the blast furnace is 10, then N is set to 4); where the first temperature detection element 4 measures the temperature of the blast furnace top gas, the pressure detection element 5 measures the pressure value of the blast furnace top, and the second temperature detection element 6 measures the temperature of the raw gas at the inlet of the dry dust collector bag box 3; the set value of the temperature detected by the first temperature detection element 4 is 600℃, the set value of the temperature detected by the second temperature detection element 6 is 350℃, and the set value of the pressure detection element 5 is 50kPa;

[0033] The control principle of the high-temperature protection control program is as follows:

[0034] When the temperature of the blast furnace top gas is ≥A or the temperature of the raw gas at the inlet of the dry bag filter is ≥B, and the pressure at the furnace top is ≥C, and the above conditions are met for 5 seconds, the high temperature protection control program will be activated; A, B, and C are numbers greater than 0, the units of A and B are ℃, and the unit of C is kPa.

[0035] Furthermore, A takes the value 600.

[0036] Furthermore, B takes the value 350.

[0037] Furthermore, C takes the value 50.

[0038] B. Closing the dry dust collector bag box 3 after sorting N: The high temperature protection control program is activated. After closing the inlet and outlet butterfly valves 10 of the first N dry dust collector bag boxes 3, if the temperature value detected by the first temperature detection element 4 or the second temperature detection element 6 still exceeds the set value, the inlet and outlet butterfly valves 10 of the dry dust collector bag boxes 3 after sorting N will be automatically closed gradually according to the decreasing rate of the blast furnace cold air flow Q.

[0039] The closing control principle of the dry-process bag filter box after sorting N is as follows:

[0040] The cold air flow rate Qmax during blast furnace full-air production is divided equally according to the minimum number K of the required operating boxes. For every 1 / K decrease in the cold air flow rate Q, in addition to closing N dry-process box inlet and outlet butterfly valves 10, one more set of box inlet and outlet butterfly valves 10 is closed according to the pre-set dry-process bag filter box sequence. That is:

[0041] When [(KD-1) / K]*Qmax<Q≤[(KD) / K]*Qmax, close the inlet butterfly valve 7 and outlet butterfly valve 10 of the N+D boxes in the sorting sequence, where D is a natural number; the value of S is the minimum number of boxes to be put into use corresponding to the cold air flow rate Qmax required for safe production of the blast furnace, S≤D≤K. For example:

[0042] When [(K-2) / K]*Qmax<Q≤[(K-1) / K]*Qmax, close the inlet butterfly valve 7 and outlet butterfly valve 10 of box N+1;

[0043] When [(K-3) / K]*Qmax<Q≤[(K-2) / K]*Qmax, close the inlet butterfly valve 7 and outlet butterfly valve 10 of box N+2;

[0044] This process continues until the Sth enclosure is closed.

[0045] (3) Resumption of use: When the first temperature detection element 4 and the second temperature detection element 6 detect a temperature value less than or equal to the set value, an alarm is issued that “gas temperature drops, please put the box into use in time”. At this time, the operator shall restore the dry dust collector bag box 3 into use in time according to the blast furnace production situation.

[0046] (4) Instrument detection: Before executing the high temperature protection control program, first determine whether the instrument detection is normal. When the instrument detection is normal, the high temperature protection control program is effective; when the instrument detection is abnormal, the high temperature protection control program is ineffective.

[0047] Specifically, if any of the following conditions are met, the instrument detection is abnormal and the high-temperature protection control program is ineffective;

[0048] If the temperature of the blast furnace top gas is <0 or >1500℃, the blast furnace top gas temperature detection is considered distorted.

[0049] If the raw gas temperature at the inlet of the dry bag filter is <0 or >1500℃, the raw gas temperature detection at the inlet of the dry bag filter is determined to be distorted.

[0050] If the furnace top pressure is <0 or >460kPa, it is determined that the furnace top pressure detection is distorted.

[0051] In summary, by adopting the method of this application, when the blast furnace gas temperature is too high, a portion of the filter box can be quickly and automatically shut down for protection, reducing the number of filter bags burned, promoting the safe and stable operation of the blast furnace dry bag dust removal system, and effectively extending the service life of the dry filter bags.

[0052] The above embodiments are merely examples of several implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention.

Claims

1. A high-temperature protection control method for a bag filter for dry dedusting of a blast furnace, characterized by, The method includes the following steps: (1) Setting up a control system: The control system includes a blast furnace, a gravity dust collector, and a dry dust collector bag box connected in sequence by pipelines. The blast furnace is equipped with a first temperature detection element and a pressure detection element. There are several dry dust collector bag boxes. A second temperature detection element, an inlet butterfly valve, and an inlet gate valve are sequentially installed on the pipeline connecting the gravity dust collector and each dry dust collector bag box. The second temperature detection element, the inlet butterfly valve, and the inlet gate valve are all located on the inlet pipeline of the dry dust collector bag box. An outlet gate valve and an outlet butterfly valve are installed on the outlet pipeline of the dry dust collector bag box. The control system also includes a controller and an alarm device. The alarm device, the first temperature detection element, the second temperature detection element, and the pressure detection element are all electrically connected to the controller. (2) High temperature protection: A. Closing the first N dry dust collector bag boxes: When the first or second temperature detection element detects a temperature value greater than the set value, and the pressure detection element detects a pressure value greater than the set value, the alarm device is activated. After 5 seconds of alarm, the high-temperature protection control program is activated, specifically: automatically and quickly closing the inlet and outlet butterfly valves of the first N dry dust collector bag boxes in a pre-set sequence. The value of N is determined based on the minimum number of bags K corresponding to the required cold air flow rate Qmax during blast furnace full-air production; N = total number of dry dust collector bag boxes - K; K ≤ N; B. Closing the dry dust collector bag boxes after sequence N: The high temperature protection control program is activated. After closing the inlet and outlet butterfly valves of the first N dry dust collector bag boxes, if the temperature value detected by the first or second temperature detection element still exceeds the set value, the inlet and outlet butterfly valves of the dry dust collector bag boxes after sequence N will be automatically closed gradually according to the decreasing rate of the blast furnace cold air flow Q. (3) Resumption of use: When the first temperature detection element and the second temperature detection element detect a temperature value less than or equal to the set value, an alarm is issued saying "Gas temperature drops, please put the box into use in time". At this time, the operator shall restore the dry dust collector bag box into use in time according to the blast furnace production situation.

2. The method for high-temperature protection and control of dry dust collector bags in blast furnaces according to claim 1, characterized in that, In step (2), the number of the first temperature detection elements is four, and the detected temperature value is the average of the four detection values.

3. The method for high-temperature protection and control of dry dust collector bags in blast furnaces according to claim 1, characterized in that, The number of dry dust collector bag boxes in step (1) is 14.

4. The high-temperature protection and control method for dry dust collector bags in blast furnaces according to claim 1, characterized in that, The pre-set sorting of dry dust collector bag boxes in step (2) is determined according to the order in which the bags are put into use. The most recently put into use bag box is sorted as 1, and so on.

5. The method for high-temperature protection and control of dry dust collector bags in blast furnaces according to claim 1, characterized in that, In steps (2) and (3), the set temperature of the first temperature sensing element is 600℃, the set temperature of the second temperature sensing element is 350℃, and the set pressure sensing element is 50kPa.

6. The method for high-temperature protection and control of dry dust collector bags in blast furnaces according to claim 1, characterized in that, It also includes the instrument detection step, specifically: before executing the high temperature protection control program, first determine whether the instrument detection is normal. When the instrument detection is normal, the high temperature protection control program is effective; when the instrument detection is abnormal, the high temperature protection control program is ineffective.

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